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000
FXUS66 KOTX 211756
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
956 AM PST FRI NOV 21 2014

.SYNOPSIS...
A strong and moist Pacific storm will bring valley rain and
mountain snow to the Cascades this afternoon and spread across
much of the Inland Northwest overnight. Then windy to breezy
conditions with mountain snow showers are expected on Saturday and
Sunday. An active and somewhat wet weather regime will continue
into the next week.

&&

.DISCUSSION...
Made a few updates to the forecast. Patchy fog which was evident
across much of the Columbia Basin to the western Palouse will lift
with the advancing warm front through this morning. Some light
freezing or frozen precipitation is possible in the northern
valleys with increasing isentropic lift through the morning hours.
But the main precipitation band will increase across the Cascades
by midday and gradually spread eastward through the afternoon and
overnight. Based on surface temperatures and temperature profiles,
there is a risk of freezing rain late this afternoon from the
Wenatchee area, across the Waterville Plateau and near Moses Lake.
Otherwise snow will be the main story for much of the Cascades to
the Okanogan Highlands through this evening. /rfox.

&&

.AVIATION...
18Z TAFS: Cigs and vsbys will improve this morning as the low
levels mix ahead of the advancing warm front from KEAT to KGEG.
VFR conditions will prevail from KPUW to KLWS under light east to
southeast winds. A very moist Pacific storm system will spread
-SN/-RA from the Cascades eastward through the afternoon. Did slow
down the timing slightly with the main precipitation reaching KEAT
after 21z, KMWH 22z and KGEG after 00z. Pcpn will vary btwn -SN,
-RA and -FZRA at KEAT and possibly KMWH and could be moderate at
times. Warmer conditions will bring rain to KGEG/KSFF/KCOE/KPUW/KLWS.
Ceilings with the precipitation are once again expected to drop to
MVFR or even IFR conditions. By Saturday morning, post frontal
westerly winds will increase, although some areas of MVFR
cigs/vsbys will linger. /rfox

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        37  36  42  30  38  29 /  30 100  20  20  70  30
Coeur d`Alene  38  36  42  31  39  30 /  40 100  50  20  70  40
Pullman        42  37  44  33  41  31 /  10 100  80  50  70  60
Lewiston       46  41  48  36  46  34 /  10 100  70  30  60  40
Colville       36  34  42  23  37  23 /  90 100  20  10  60  20
Sandpoint      34  34  40  29  37  30 /  80 100  70  30  70  40
Kellogg        36  35  39  31  35  31 /  60 100  90  60  80  60
Moses Lake     36  33  47  28  44  29 /  90 100  10  10  30  10
Wenatchee      34  34  45  33  43  31 / 100 100  20  10  40  20
Omak           34  32  42  26  37  27 / 100 100  10  10  30  20

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Air Stagnation Advisory until Noon PST today for Central
     Panhandle Mountains-Coeur d`Alene Area-Idaho Palouse-
     Northern Panhandle.

     Winter Storm Warning until 6 PM PST Saturday for Northern
     Panhandle.

     Winter Storm Warning until 6 AM PST Sunday for Central Panhandle
     Mountains.

WA...Air Stagnation Advisory until Noon PST today for East Slopes
     Northern Cascades-Lower Garfield and Asotin Counties-Moses
     Lake Area-Northeast Mountains-Okanogan Highlands-Spokane
     Area-Upper Columbia Basin-Washington Palouse-Waterville
     Plateau-Wenatchee Area.

     Winter Storm Warning until 6 AM PST Saturday for East Slopes
     Northern Cascades-Okanogan Highlands-Okanogan Valley-
     Waterville Plateau.

     Winter Storm Warning until 6 PM PST Saturday for Northeast
     Mountains.

     Winter Weather Advisory until 6 AM PST Saturday for Wenatchee
     Area.

&&

$$




000
FXUS66 KOTX 211756
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
956 AM PST FRI NOV 21 2014

.SYNOPSIS...
A strong and moist Pacific storm will bring valley rain and
mountain snow to the Cascades this afternoon and spread across
much of the Inland Northwest overnight. Then windy to breezy
conditions with mountain snow showers are expected on Saturday and
Sunday. An active and somewhat wet weather regime will continue
into the next week.

&&

.DISCUSSION...
Made a few updates to the forecast. Patchy fog which was evident
across much of the Columbia Basin to the western Palouse will lift
with the advancing warm front through this morning. Some light
freezing or frozen precipitation is possible in the northern
valleys with increasing isentropic lift through the morning hours.
But the main precipitation band will increase across the Cascades
by midday and gradually spread eastward through the afternoon and
overnight. Based on surface temperatures and temperature profiles,
there is a risk of freezing rain late this afternoon from the
Wenatchee area, across the Waterville Plateau and near Moses Lake.
Otherwise snow will be the main story for much of the Cascades to
the Okanogan Highlands through this evening. /rfox.

&&

.AVIATION...
18Z TAFS: Cigs and vsbys will improve this morning as the low
levels mix ahead of the advancing warm front from KEAT to KGEG.
VFR conditions will prevail from KPUW to KLWS under light east to
southeast winds. A very moist Pacific storm system will spread
-SN/-RA from the Cascades eastward through the afternoon. Did slow
down the timing slightly with the main precipitation reaching KEAT
after 21z, KMWH 22z and KGEG after 00z. Pcpn will vary btwn -SN,
-RA and -FZRA at KEAT and possibly KMWH and could be moderate at
times. Warmer conditions will bring rain to KGEG/KSFF/KCOE/KPUW/KLWS.
Ceilings with the precipitation are once again expected to drop to
MVFR or even IFR conditions. By Saturday morning, post frontal
westerly winds will increase, although some areas of MVFR
cigs/vsbys will linger. /rfox

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        37  36  42  30  38  29 /  30 100  20  20  70  30
Coeur d`Alene  38  36  42  31  39  30 /  40 100  50  20  70  40
Pullman        42  37  44  33  41  31 /  10 100  80  50  70  60
Lewiston       46  41  48  36  46  34 /  10 100  70  30  60  40
Colville       36  34  42  23  37  23 /  90 100  20  10  60  20
Sandpoint      34  34  40  29  37  30 /  80 100  70  30  70  40
Kellogg        36  35  39  31  35  31 /  60 100  90  60  80  60
Moses Lake     36  33  47  28  44  29 /  90 100  10  10  30  10
Wenatchee      34  34  45  33  43  31 / 100 100  20  10  40  20
Omak           34  32  42  26  37  27 / 100 100  10  10  30  20

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Air Stagnation Advisory until Noon PST today for Central
     Panhandle Mountains-Coeur d`Alene Area-Idaho Palouse-
     Northern Panhandle.

     Winter Storm Warning until 6 PM PST Saturday for Northern
     Panhandle.

     Winter Storm Warning until 6 AM PST Sunday for Central Panhandle
     Mountains.

WA...Air Stagnation Advisory until Noon PST today for East Slopes
     Northern Cascades-Lower Garfield and Asotin Counties-Moses
     Lake Area-Northeast Mountains-Okanogan Highlands-Spokane
     Area-Upper Columbia Basin-Washington Palouse-Waterville
     Plateau-Wenatchee Area.

     Winter Storm Warning until 6 AM PST Saturday for East Slopes
     Northern Cascades-Okanogan Highlands-Okanogan Valley-
     Waterville Plateau.

     Winter Storm Warning until 6 PM PST Saturday for Northeast
     Mountains.

     Winter Weather Advisory until 6 AM PST Saturday for Wenatchee
     Area.

&&

$$




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000
FXUS66 KPQR 211741
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
942 AM PST FRI NOV 21 2014

.SYNOPSIS...MORE TYPICAL FALL WEATHER IN STORE FOR SOUTHWEST
WASHINGTON AND NORTHWEST OREGON TODAY. A FAIRLY STRONG AND MOIST
FRONTAL SYSTEM WILL BRING GUSTY COASTAL WINDS AND HEAVY RAIN TO THE
REGION TODAY AND TONIGHT. COOLER AIR BEHIND THIS SYSTEM WILL CAUSE
THE SNOW LEVELS TO LOWER BELOW THE CASCADE PASSES EARLY SATURDAY
WHILE STRONG ONSHORE FLOW CONTINUES THROUGH THE WEEKEND. AS A RESULT
SNOW MAY BECOME HEAVY AT TIMES ALL THE WAY DOWN TO PASS LEVELS THIS
WEEKEND. ANOTHER SYSTEM IS LIKELY TO AFFECT THE REGION EARLY NEXT
WEEK...THEN PERHAPS SOME DRIER WEATHER BY MIDWEEK.

&&

.SHORT TERM...A FAIRLY STRONG AND MOIST FRONTAL SYSTEM IS RAPIDLY
APPROACHING THE NW COAST TODAY...RIDING A ROBUST 160+ KT UPPER LEVEL
JET. A PRECIPITATION SHIELD ASSOCIATED WITH ISENTROPIC LIFT AHEAD OF
THE LEADING WARM FRONT IS MOVING ONSHORE THIS MORNING. THE STEADIER
PRECIPITATION IS MAINLY CONFINED TO THE COAST SO FAR...BUT WILL
PROCEED INLAND LATER THIS MORNING AND THIS AFTERNOON. THE LATEST
SURFACE OBSERVATIONS ARE STILL SHOWING SOME TEMPS AROUND FREEZING IN
THE CENTRAL COLUMBIA RIVER GORGE AND UPPER HOOD RIVER VALLEY...SO
THERE MAY BE SOME PATCHY FREEZING RAIN DURING THE ONSET OF PRECIP
THIS MORNING. HOWEVER...EXPECT TEMPS TO RISE ABOVE FREEZING OVER THE
NEXT FEW HOURS...EFFECTIVELY ENDING ANY ICING CONCERNS.

SOUTHERLY WINDS SHOULD BEGIN TO PICK UP ALONG THE COAST AROUND
MIDDAY. BASED ON THE LATEST SHORT TERM RAP AND HRRR MODEL
RUNS...DECIDED TO EXPAND THE EXISTING HIGH WIND WARNING FOR THE NORTH
AND CENTRAL OREGON COAST TO INCLUDE THE SOUTH WASHINGTON COAST AS
WELL. IT APPEARS THAT THE SURFACE LOW MIGHT BE TRACKING A BIT FURTHER
NORTH THAN PREVIOUSLY ANTICIPATED...WHICH MAY OPEN THE DOOR FOR AREAS
LIKE CAPE DISAPPOINTMENT TO PICK UP A FEW HIGH WIND CRITERIA GUSTS.
OVERALL...IT STILL LOOKS LIKE A FAIRLY MARGINAL WIND EVENT. SOME
BEACH AND EXPOSED HEADLAND LOCATIONS MAY SEE A FEW GUSTS AROUND 60 TO
65 MPH...BUT THE COASTAL COMMUNITIES WILL LIKELY SEE WINDS TOPPING
OUT AROUND 50 TO 55 MPH. THE COLD FRONT IS EXPECTED TO MOVE ONSHORE
AROUND 4 TO 6 PM...AFTER WHICH THE COASTAL WINDS SHOULD DROP OFF
RAPIDLY. THE INTERIOR LOWLANDS MAY ALSO EXPERIENCE A BRIEF PERIOD OF
GUSTY WINDS IN THE LATE AFTERNOON/EARLY EVENING AS THE COLD FRONT
MOVES THROUGH.

A BATCH OF HEAVY RAIN WILL PUSH INLAND DURING THE LATE AFTERNOON AND
EVENING...WITH 1.5 TO 2 INCHES OF RAIN LIKELY FOR THE
COAST...COAST RANGE AND CASCADES OVER ABOUT A 12 HR PERIOD ENDING
TONIGHT. THE INTERIOR LOWLANDS WILL BE CLOSER TO AN INCH. IT DOES NOT
APPEAR THAT RAINFALL TOTALS WILL BE ENOUGH TO CAUSE ANY FLOODING
CONCERNS.

SNOW LEVELS WILL INCREASE ABOVE ALL BUT THE HIGHEST PEAKS IN
THE AREA TODAY WITH THE WARM FRONT. SNOW LEVELS WILL CRASH
TO AROUND 3000 TO 4000 FT SATURDAY MORNING. OROGRAPHICS BECOME
FAVORABLE IN THIS COLDER AIR MASS. 850 MB WINDS ARE WESTERLY 25 TO
45 KT SAT ALONG WITH ABUNDANT SHOWERS. SNOW WILL BE HEAVIER AT TIMES
AS IMPULSES MOVE THROUGH. IT APPEARS THE PERIOD OF HIGHER SNOWFALL
ACCUMULATION WILL BE SAT INTO EARLY SUN. THIS PERIOD MAY END UP
NEEDING A WINTER WEATHER ADVISORY.  CURRENT SPECIAL WEATHER
STATEMENT COVERS THIS UNTIL THEN.

500 MB TEMPERATURES DROP TO AROUND -25 TO -30 C ON SATURDAY. LIFTED
INDEX LOWERS TO AROUND 0 TO -2. THERE IS ALSO A WEAK VORT MAX THAT
MOVES THROUGH DURING THE DAY TO ASSIST IN THE INSTABILITY. SO HAVE
ADDED A SLIGHT CHANCE OF THUNDERSTORMS OVER THE WATERS AND INLAND TO
THE COAST RANGE. THE INTERIOR LOWLAND MAY NEED TO BE ADDED AS
WELL...BUT THREAT APPEARS TOO LOW AT THIS TIME. PYLE/26


.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY. THE MORE WESTERLY OR
ZONAL FLOW THAT SETS UP OVER THE WEEKEND DURING THE LATTER PART OF
THE SHORT TERM PERIOD BEGINS TO BUCKLE A BIT IN THE EARLY PART OF
THE LONG TERM PERIOD WITH SOME FLAT RIDGING DEVELOPING OVER THE
NORTHEAST PACIFIC. HAVE DECIDED TO CONTINUE TO STICK MORE WITH A
DIRTY RIDGE SCENARIO OF THE ECMWF VS THE HIGHER AMPLITUDE RIDGING OF
THE OPERATIONAL GFS MODEL. CONFIDENCE DECREASES THROUGHOUT THE LONG
TERM PERIOD AS MODEL VARIABILITY INCREASES...THOUGH THE TREND IS
TOWARD DRIER DURING THE MIDDLE TO LATTER PARTS OF NEXT WEEK. TOLLESON

&&

.AVIATION...MIX OF VFR AND MVFR CIGS TO CONTINUE THIS MORNING AS
WARM FRONT LIFTS ACROSS THE AREA. WINDS WILL PICK UP FROM THE
SOUTH BEHIND THIS FRONT...LIFTING MOST THE AREA TO VFR CIGS. MAY
BE SOME SPEED SHEAR JUST ABOVE THE GROUND...AS SOUTHERLIES
INCREASE FROM 10 TO 30 OR 40 KTS BELOW FL030. EXPECT MIX OF VFR
AND MVFR TO PERSIST ACROSS THE AREA...THOUGH STRONG LOW-LEVEL
WINDS MAY KEEP CIGS MAINLY VFR. COLD FRONT MOVES THROUGH AROUND
06Z TO 09Z WHICH WILL ALLOW WINDS TO DIE DOWN THIS
EVENING...BRINGING CIGS BACK DOWN TO MVFR AND SOME IFR TONIGHT.

KPDX AND APPROACHES...VFR CONTINUES THROUGH THIS MORNING...THOUGH
HEAVIER SHOWERS MAY CAUSE OCCASIONAL MVFR CIGS. SOUTHERLIES
INCREASE FROM 10 KTS AT THE SURFACE TO 30 OR 40 KTS BELOW FL030
THIS AFTERNOON...BUT WILL DECREASE BEHIND COLD FRONT AROUND 06Z TO
09Z THIS EVENING.

-MCCOY

&&

.MARINE...GALE WARNING IN EFFECT THROUGH THIS EVENING. SOUTHERLY
WINDS CURRENTLY 20 TO 25 KTS GUSTING TO 35 CURRENTLY...AND WILL
CONTINUE TO RAMP UP THROUGH THIS AFTERNOON. EXPECTING SOLID GALES
WITH SOME STORM FORCE GUSTS POSSIBLE...MAINLY IN THE INNER WATERS
WITH A COASTAL JET. STRONGEST WINDS WILL OCCUR DURING THE
AFTERNOON HOURS...BEFORE DECREASING THIS EVENING BEHIND THE COLD
FRONT.

SEAS 10 TO 12 FT THIS MORNING WILL BUILD QUICKLY THIS AFTERNOON TO
NEAR 20 FT BY 4-6PM THIS EVENING. SEAS WILL SUBSIDE BEHIND THE
FRONT...DROPPING TO 12 TO 14 FT BY MIDNIGHT. SMALL CRAFT ADVISORY
SEAS ABOVE 10 FT LOOK TO PERSIST THROUGH THIS WEEKEND.

-MCCOY

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...HIGH WIND WARNING UNTIL 7 PM PST THIS EVENING FOR CENTRAL
    OREGON COAST-NORTH OREGON COAST.

WA...HIGH WIND WARNING UNTIL 7 PM PST THIS EVENING FOR SOUTH
     WASHINGTON COAST.

PZ...GALE WARNING UNTIL 10 PM PST THIS EVENING FOR COASTAL WATERS
    FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 10 PM
    PST THIS EVENING.

&&

$$

INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND

THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.



000
FXUS66 KPQR 211741
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
942 AM PST FRI NOV 21 2014

.SYNOPSIS...MORE TYPICAL FALL WEATHER IN STORE FOR SOUTHWEST
WASHINGTON AND NORTHWEST OREGON TODAY. A FAIRLY STRONG AND MOIST
FRONTAL SYSTEM WILL BRING GUSTY COASTAL WINDS AND HEAVY RAIN TO THE
REGION TODAY AND TONIGHT. COOLER AIR BEHIND THIS SYSTEM WILL CAUSE
THE SNOW LEVELS TO LOWER BELOW THE CASCADE PASSES EARLY SATURDAY
WHILE STRONG ONSHORE FLOW CONTINUES THROUGH THE WEEKEND. AS A RESULT
SNOW MAY BECOME HEAVY AT TIMES ALL THE WAY DOWN TO PASS LEVELS THIS
WEEKEND. ANOTHER SYSTEM IS LIKELY TO AFFECT THE REGION EARLY NEXT
WEEK...THEN PERHAPS SOME DRIER WEATHER BY MIDWEEK.

&&

.SHORT TERM...A FAIRLY STRONG AND MOIST FRONTAL SYSTEM IS RAPIDLY
APPROACHING THE NW COAST TODAY...RIDING A ROBUST 160+ KT UPPER LEVEL
JET. A PRECIPITATION SHIELD ASSOCIATED WITH ISENTROPIC LIFT AHEAD OF
THE LEADING WARM FRONT IS MOVING ONSHORE THIS MORNING. THE STEADIER
PRECIPITATION IS MAINLY CONFINED TO THE COAST SO FAR...BUT WILL
PROCEED INLAND LATER THIS MORNING AND THIS AFTERNOON. THE LATEST
SURFACE OBSERVATIONS ARE STILL SHOWING SOME TEMPS AROUND FREEZING IN
THE CENTRAL COLUMBIA RIVER GORGE AND UPPER HOOD RIVER VALLEY...SO
THERE MAY BE SOME PATCHY FREEZING RAIN DURING THE ONSET OF PRECIP
THIS MORNING. HOWEVER...EXPECT TEMPS TO RISE ABOVE FREEZING OVER THE
NEXT FEW HOURS...EFFECTIVELY ENDING ANY ICING CONCERNS.

SOUTHERLY WINDS SHOULD BEGIN TO PICK UP ALONG THE COAST AROUND
MIDDAY. BASED ON THE LATEST SHORT TERM RAP AND HRRR MODEL
RUNS...DECIDED TO EXPAND THE EXISTING HIGH WIND WARNING FOR THE NORTH
AND CENTRAL OREGON COAST TO INCLUDE THE SOUTH WASHINGTON COAST AS
WELL. IT APPEARS THAT THE SURFACE LOW MIGHT BE TRACKING A BIT FURTHER
NORTH THAN PREVIOUSLY ANTICIPATED...WHICH MAY OPEN THE DOOR FOR AREAS
LIKE CAPE DISAPPOINTMENT TO PICK UP A FEW HIGH WIND CRITERIA GUSTS.
OVERALL...IT STILL LOOKS LIKE A FAIRLY MARGINAL WIND EVENT. SOME
BEACH AND EXPOSED HEADLAND LOCATIONS MAY SEE A FEW GUSTS AROUND 60 TO
65 MPH...BUT THE COASTAL COMMUNITIES WILL LIKELY SEE WINDS TOPPING
OUT AROUND 50 TO 55 MPH. THE COLD FRONT IS EXPECTED TO MOVE ONSHORE
AROUND 4 TO 6 PM...AFTER WHICH THE COASTAL WINDS SHOULD DROP OFF
RAPIDLY. THE INTERIOR LOWLANDS MAY ALSO EXPERIENCE A BRIEF PERIOD OF
GUSTY WINDS IN THE LATE AFTERNOON/EARLY EVENING AS THE COLD FRONT
MOVES THROUGH.

A BATCH OF HEAVY RAIN WILL PUSH INLAND DURING THE LATE AFTERNOON AND
EVENING...WITH 1.5 TO 2 INCHES OF RAIN LIKELY FOR THE
COAST...COAST RANGE AND CASCADES OVER ABOUT A 12 HR PERIOD ENDING
TONIGHT. THE INTERIOR LOWLANDS WILL BE CLOSER TO AN INCH. IT DOES NOT
APPEAR THAT RAINFALL TOTALS WILL BE ENOUGH TO CAUSE ANY FLOODING
CONCERNS.

SNOW LEVELS WILL INCREASE ABOVE ALL BUT THE HIGHEST PEAKS IN
THE AREA TODAY WITH THE WARM FRONT. SNOW LEVELS WILL CRASH
TO AROUND 3000 TO 4000 FT SATURDAY MORNING. OROGRAPHICS BECOME
FAVORABLE IN THIS COLDER AIR MASS. 850 MB WINDS ARE WESTERLY 25 TO
45 KT SAT ALONG WITH ABUNDANT SHOWERS. SNOW WILL BE HEAVIER AT TIMES
AS IMPULSES MOVE THROUGH. IT APPEARS THE PERIOD OF HIGHER SNOWFALL
ACCUMULATION WILL BE SAT INTO EARLY SUN. THIS PERIOD MAY END UP
NEEDING A WINTER WEATHER ADVISORY.  CURRENT SPECIAL WEATHER
STATEMENT COVERS THIS UNTIL THEN.

500 MB TEMPERATURES DROP TO AROUND -25 TO -30 C ON SATURDAY. LIFTED
INDEX LOWERS TO AROUND 0 TO -2. THERE IS ALSO A WEAK VORT MAX THAT
MOVES THROUGH DURING THE DAY TO ASSIST IN THE INSTABILITY. SO HAVE
ADDED A SLIGHT CHANCE OF THUNDERSTORMS OVER THE WATERS AND INLAND TO
THE COAST RANGE. THE INTERIOR LOWLAND MAY NEED TO BE ADDED AS
WELL...BUT THREAT APPEARS TOO LOW AT THIS TIME. PYLE/26


.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY. THE MORE WESTERLY OR
ZONAL FLOW THAT SETS UP OVER THE WEEKEND DURING THE LATTER PART OF
THE SHORT TERM PERIOD BEGINS TO BUCKLE A BIT IN THE EARLY PART OF
THE LONG TERM PERIOD WITH SOME FLAT RIDGING DEVELOPING OVER THE
NORTHEAST PACIFIC. HAVE DECIDED TO CONTINUE TO STICK MORE WITH A
DIRTY RIDGE SCENARIO OF THE ECMWF VS THE HIGHER AMPLITUDE RIDGING OF
THE OPERATIONAL GFS MODEL. CONFIDENCE DECREASES THROUGHOUT THE LONG
TERM PERIOD AS MODEL VARIABILITY INCREASES...THOUGH THE TREND IS
TOWARD DRIER DURING THE MIDDLE TO LATTER PARTS OF NEXT WEEK. TOLLESON

&&

.AVIATION...MIX OF VFR AND MVFR CIGS TO CONTINUE THIS MORNING AS
WARM FRONT LIFTS ACROSS THE AREA. WINDS WILL PICK UP FROM THE
SOUTH BEHIND THIS FRONT...LIFTING MOST THE AREA TO VFR CIGS. MAY
BE SOME SPEED SHEAR JUST ABOVE THE GROUND...AS SOUTHERLIES
INCREASE FROM 10 TO 30 OR 40 KTS BELOW FL030. EXPECT MIX OF VFR
AND MVFR TO PERSIST ACROSS THE AREA...THOUGH STRONG LOW-LEVEL
WINDS MAY KEEP CIGS MAINLY VFR. COLD FRONT MOVES THROUGH AROUND
06Z TO 09Z WHICH WILL ALLOW WINDS TO DIE DOWN THIS
EVENING...BRINGING CIGS BACK DOWN TO MVFR AND SOME IFR TONIGHT.

KPDX AND APPROACHES...VFR CONTINUES THROUGH THIS MORNING...THOUGH
HEAVIER SHOWERS MAY CAUSE OCCASIONAL MVFR CIGS. SOUTHERLIES
INCREASE FROM 10 KTS AT THE SURFACE TO 30 OR 40 KTS BELOW FL030
THIS AFTERNOON...BUT WILL DECREASE BEHIND COLD FRONT AROUND 06Z TO
09Z THIS EVENING.

-MCCOY

&&

.MARINE...GALE WARNING IN EFFECT THROUGH THIS EVENING. SOUTHERLY
WINDS CURRENTLY 20 TO 25 KTS GUSTING TO 35 CURRENTLY...AND WILL
CONTINUE TO RAMP UP THROUGH THIS AFTERNOON. EXPECTING SOLID GALES
WITH SOME STORM FORCE GUSTS POSSIBLE...MAINLY IN THE INNER WATERS
WITH A COASTAL JET. STRONGEST WINDS WILL OCCUR DURING THE
AFTERNOON HOURS...BEFORE DECREASING THIS EVENING BEHIND THE COLD
FRONT.

SEAS 10 TO 12 FT THIS MORNING WILL BUILD QUICKLY THIS AFTERNOON TO
NEAR 20 FT BY 4-6PM THIS EVENING. SEAS WILL SUBSIDE BEHIND THE
FRONT...DROPPING TO 12 TO 14 FT BY MIDNIGHT. SMALL CRAFT ADVISORY
SEAS ABOVE 10 FT LOOK TO PERSIST THROUGH THIS WEEKEND.

-MCCOY

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...HIGH WIND WARNING UNTIL 7 PM PST THIS EVENING FOR CENTRAL
    OREGON COAST-NORTH OREGON COAST.

WA...HIGH WIND WARNING UNTIL 7 PM PST THIS EVENING FOR SOUTH
     WASHINGTON COAST.

PZ...GALE WARNING UNTIL 10 PM PST THIS EVENING FOR COASTAL WATERS
    FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 10 PM
    PST THIS EVENING.

&&

$$

INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND

THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.



000
FXUS66 KPQR 211741
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
942 AM PST FRI NOV 21 2014

.SYNOPSIS...MORE TYPICAL FALL WEATHER IN STORE FOR SOUTHWEST
WASHINGTON AND NORTHWEST OREGON TODAY. A FAIRLY STRONG AND MOIST
FRONTAL SYSTEM WILL BRING GUSTY COASTAL WINDS AND HEAVY RAIN TO THE
REGION TODAY AND TONIGHT. COOLER AIR BEHIND THIS SYSTEM WILL CAUSE
THE SNOW LEVELS TO LOWER BELOW THE CASCADE PASSES EARLY SATURDAY
WHILE STRONG ONSHORE FLOW CONTINUES THROUGH THE WEEKEND. AS A RESULT
SNOW MAY BECOME HEAVY AT TIMES ALL THE WAY DOWN TO PASS LEVELS THIS
WEEKEND. ANOTHER SYSTEM IS LIKELY TO AFFECT THE REGION EARLY NEXT
WEEK...THEN PERHAPS SOME DRIER WEATHER BY MIDWEEK.

&&

.SHORT TERM...A FAIRLY STRONG AND MOIST FRONTAL SYSTEM IS RAPIDLY
APPROACHING THE NW COAST TODAY...RIDING A ROBUST 160+ KT UPPER LEVEL
JET. A PRECIPITATION SHIELD ASSOCIATED WITH ISENTROPIC LIFT AHEAD OF
THE LEADING WARM FRONT IS MOVING ONSHORE THIS MORNING. THE STEADIER
PRECIPITATION IS MAINLY CONFINED TO THE COAST SO FAR...BUT WILL
PROCEED INLAND LATER THIS MORNING AND THIS AFTERNOON. THE LATEST
SURFACE OBSERVATIONS ARE STILL SHOWING SOME TEMPS AROUND FREEZING IN
THE CENTRAL COLUMBIA RIVER GORGE AND UPPER HOOD RIVER VALLEY...SO
THERE MAY BE SOME PATCHY FREEZING RAIN DURING THE ONSET OF PRECIP
THIS MORNING. HOWEVER...EXPECT TEMPS TO RISE ABOVE FREEZING OVER THE
NEXT FEW HOURS...EFFECTIVELY ENDING ANY ICING CONCERNS.

SOUTHERLY WINDS SHOULD BEGIN TO PICK UP ALONG THE COAST AROUND
MIDDAY. BASED ON THE LATEST SHORT TERM RAP AND HRRR MODEL
RUNS...DECIDED TO EXPAND THE EXISTING HIGH WIND WARNING FOR THE NORTH
AND CENTRAL OREGON COAST TO INCLUDE THE SOUTH WASHINGTON COAST AS
WELL. IT APPEARS THAT THE SURFACE LOW MIGHT BE TRACKING A BIT FURTHER
NORTH THAN PREVIOUSLY ANTICIPATED...WHICH MAY OPEN THE DOOR FOR AREAS
LIKE CAPE DISAPPOINTMENT TO PICK UP A FEW HIGH WIND CRITERIA GUSTS.
OVERALL...IT STILL LOOKS LIKE A FAIRLY MARGINAL WIND EVENT. SOME
BEACH AND EXPOSED HEADLAND LOCATIONS MAY SEE A FEW GUSTS AROUND 60 TO
65 MPH...BUT THE COASTAL COMMUNITIES WILL LIKELY SEE WINDS TOPPING
OUT AROUND 50 TO 55 MPH. THE COLD FRONT IS EXPECTED TO MOVE ONSHORE
AROUND 4 TO 6 PM...AFTER WHICH THE COASTAL WINDS SHOULD DROP OFF
RAPIDLY. THE INTERIOR LOWLANDS MAY ALSO EXPERIENCE A BRIEF PERIOD OF
GUSTY WINDS IN THE LATE AFTERNOON/EARLY EVENING AS THE COLD FRONT
MOVES THROUGH.

A BATCH OF HEAVY RAIN WILL PUSH INLAND DURING THE LATE AFTERNOON AND
EVENING...WITH 1.5 TO 2 INCHES OF RAIN LIKELY FOR THE
COAST...COAST RANGE AND CASCADES OVER ABOUT A 12 HR PERIOD ENDING
TONIGHT. THE INTERIOR LOWLANDS WILL BE CLOSER TO AN INCH. IT DOES NOT
APPEAR THAT RAINFALL TOTALS WILL BE ENOUGH TO CAUSE ANY FLOODING
CONCERNS.

SNOW LEVELS WILL INCREASE ABOVE ALL BUT THE HIGHEST PEAKS IN
THE AREA TODAY WITH THE WARM FRONT. SNOW LEVELS WILL CRASH
TO AROUND 3000 TO 4000 FT SATURDAY MORNING. OROGRAPHICS BECOME
FAVORABLE IN THIS COLDER AIR MASS. 850 MB WINDS ARE WESTERLY 25 TO
45 KT SAT ALONG WITH ABUNDANT SHOWERS. SNOW WILL BE HEAVIER AT TIMES
AS IMPULSES MOVE THROUGH. IT APPEARS THE PERIOD OF HIGHER SNOWFALL
ACCUMULATION WILL BE SAT INTO EARLY SUN. THIS PERIOD MAY END UP
NEEDING A WINTER WEATHER ADVISORY.  CURRENT SPECIAL WEATHER
STATEMENT COVERS THIS UNTIL THEN.

500 MB TEMPERATURES DROP TO AROUND -25 TO -30 C ON SATURDAY. LIFTED
INDEX LOWERS TO AROUND 0 TO -2. THERE IS ALSO A WEAK VORT MAX THAT
MOVES THROUGH DURING THE DAY TO ASSIST IN THE INSTABILITY. SO HAVE
ADDED A SLIGHT CHANCE OF THUNDERSTORMS OVER THE WATERS AND INLAND TO
THE COAST RANGE. THE INTERIOR LOWLAND MAY NEED TO BE ADDED AS
WELL...BUT THREAT APPEARS TOO LOW AT THIS TIME. PYLE/26


.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY. THE MORE WESTERLY OR
ZONAL FLOW THAT SETS UP OVER THE WEEKEND DURING THE LATTER PART OF
THE SHORT TERM PERIOD BEGINS TO BUCKLE A BIT IN THE EARLY PART OF
THE LONG TERM PERIOD WITH SOME FLAT RIDGING DEVELOPING OVER THE
NORTHEAST PACIFIC. HAVE DECIDED TO CONTINUE TO STICK MORE WITH A
DIRTY RIDGE SCENARIO OF THE ECMWF VS THE HIGHER AMPLITUDE RIDGING OF
THE OPERATIONAL GFS MODEL. CONFIDENCE DECREASES THROUGHOUT THE LONG
TERM PERIOD AS MODEL VARIABILITY INCREASES...THOUGH THE TREND IS
TOWARD DRIER DURING THE MIDDLE TO LATTER PARTS OF NEXT WEEK. TOLLESON

&&

.AVIATION...MIX OF VFR AND MVFR CIGS TO CONTINUE THIS MORNING AS
WARM FRONT LIFTS ACROSS THE AREA. WINDS WILL PICK UP FROM THE
SOUTH BEHIND THIS FRONT...LIFTING MOST THE AREA TO VFR CIGS. MAY
BE SOME SPEED SHEAR JUST ABOVE THE GROUND...AS SOUTHERLIES
INCREASE FROM 10 TO 30 OR 40 KTS BELOW FL030. EXPECT MIX OF VFR
AND MVFR TO PERSIST ACROSS THE AREA...THOUGH STRONG LOW-LEVEL
WINDS MAY KEEP CIGS MAINLY VFR. COLD FRONT MOVES THROUGH AROUND
06Z TO 09Z WHICH WILL ALLOW WINDS TO DIE DOWN THIS
EVENING...BRINGING CIGS BACK DOWN TO MVFR AND SOME IFR TONIGHT.

KPDX AND APPROACHES...VFR CONTINUES THROUGH THIS MORNING...THOUGH
HEAVIER SHOWERS MAY CAUSE OCCASIONAL MVFR CIGS. SOUTHERLIES
INCREASE FROM 10 KTS AT THE SURFACE TO 30 OR 40 KTS BELOW FL030
THIS AFTERNOON...BUT WILL DECREASE BEHIND COLD FRONT AROUND 06Z TO
09Z THIS EVENING.

-MCCOY

&&

.MARINE...GALE WARNING IN EFFECT THROUGH THIS EVENING. SOUTHERLY
WINDS CURRENTLY 20 TO 25 KTS GUSTING TO 35 CURRENTLY...AND WILL
CONTINUE TO RAMP UP THROUGH THIS AFTERNOON. EXPECTING SOLID GALES
WITH SOME STORM FORCE GUSTS POSSIBLE...MAINLY IN THE INNER WATERS
WITH A COASTAL JET. STRONGEST WINDS WILL OCCUR DURING THE
AFTERNOON HOURS...BEFORE DECREASING THIS EVENING BEHIND THE COLD
FRONT.

SEAS 10 TO 12 FT THIS MORNING WILL BUILD QUICKLY THIS AFTERNOON TO
NEAR 20 FT BY 4-6PM THIS EVENING. SEAS WILL SUBSIDE BEHIND THE
FRONT...DROPPING TO 12 TO 14 FT BY MIDNIGHT. SMALL CRAFT ADVISORY
SEAS ABOVE 10 FT LOOK TO PERSIST THROUGH THIS WEEKEND.

-MCCOY

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...HIGH WIND WARNING UNTIL 7 PM PST THIS EVENING FOR CENTRAL
    OREGON COAST-NORTH OREGON COAST.

WA...HIGH WIND WARNING UNTIL 7 PM PST THIS EVENING FOR SOUTH
     WASHINGTON COAST.

PZ...GALE WARNING UNTIL 10 PM PST THIS EVENING FOR COASTAL WATERS
    FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 10 PM
    PST THIS EVENING.

&&

$$

INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND

THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.



000
FXUS66 KPQR 211741
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
942 AM PST FRI NOV 21 2014

.SYNOPSIS...MORE TYPICAL FALL WEATHER IN STORE FOR SOUTHWEST
WASHINGTON AND NORTHWEST OREGON TODAY. A FAIRLY STRONG AND MOIST
FRONTAL SYSTEM WILL BRING GUSTY COASTAL WINDS AND HEAVY RAIN TO THE
REGION TODAY AND TONIGHT. COOLER AIR BEHIND THIS SYSTEM WILL CAUSE
THE SNOW LEVELS TO LOWER BELOW THE CASCADE PASSES EARLY SATURDAY
WHILE STRONG ONSHORE FLOW CONTINUES THROUGH THE WEEKEND. AS A RESULT
SNOW MAY BECOME HEAVY AT TIMES ALL THE WAY DOWN TO PASS LEVELS THIS
WEEKEND. ANOTHER SYSTEM IS LIKELY TO AFFECT THE REGION EARLY NEXT
WEEK...THEN PERHAPS SOME DRIER WEATHER BY MIDWEEK.

&&

.SHORT TERM...A FAIRLY STRONG AND MOIST FRONTAL SYSTEM IS RAPIDLY
APPROACHING THE NW COAST TODAY...RIDING A ROBUST 160+ KT UPPER LEVEL
JET. A PRECIPITATION SHIELD ASSOCIATED WITH ISENTROPIC LIFT AHEAD OF
THE LEADING WARM FRONT IS MOVING ONSHORE THIS MORNING. THE STEADIER
PRECIPITATION IS MAINLY CONFINED TO THE COAST SO FAR...BUT WILL
PROCEED INLAND LATER THIS MORNING AND THIS AFTERNOON. THE LATEST
SURFACE OBSERVATIONS ARE STILL SHOWING SOME TEMPS AROUND FREEZING IN
THE CENTRAL COLUMBIA RIVER GORGE AND UPPER HOOD RIVER VALLEY...SO
THERE MAY BE SOME PATCHY FREEZING RAIN DURING THE ONSET OF PRECIP
THIS MORNING. HOWEVER...EXPECT TEMPS TO RISE ABOVE FREEZING OVER THE
NEXT FEW HOURS...EFFECTIVELY ENDING ANY ICING CONCERNS.

SOUTHERLY WINDS SHOULD BEGIN TO PICK UP ALONG THE COAST AROUND
MIDDAY. BASED ON THE LATEST SHORT TERM RAP AND HRRR MODEL
RUNS...DECIDED TO EXPAND THE EXISTING HIGH WIND WARNING FOR THE NORTH
AND CENTRAL OREGON COAST TO INCLUDE THE SOUTH WASHINGTON COAST AS
WELL. IT APPEARS THAT THE SURFACE LOW MIGHT BE TRACKING A BIT FURTHER
NORTH THAN PREVIOUSLY ANTICIPATED...WHICH MAY OPEN THE DOOR FOR AREAS
LIKE CAPE DISAPPOINTMENT TO PICK UP A FEW HIGH WIND CRITERIA GUSTS.
OVERALL...IT STILL LOOKS LIKE A FAIRLY MARGINAL WIND EVENT. SOME
BEACH AND EXPOSED HEADLAND LOCATIONS MAY SEE A FEW GUSTS AROUND 60 TO
65 MPH...BUT THE COASTAL COMMUNITIES WILL LIKELY SEE WINDS TOPPING
OUT AROUND 50 TO 55 MPH. THE COLD FRONT IS EXPECTED TO MOVE ONSHORE
AROUND 4 TO 6 PM...AFTER WHICH THE COASTAL WINDS SHOULD DROP OFF
RAPIDLY. THE INTERIOR LOWLANDS MAY ALSO EXPERIENCE A BRIEF PERIOD OF
GUSTY WINDS IN THE LATE AFTERNOON/EARLY EVENING AS THE COLD FRONT
MOVES THROUGH.

A BATCH OF HEAVY RAIN WILL PUSH INLAND DURING THE LATE AFTERNOON AND
EVENING...WITH 1.5 TO 2 INCHES OF RAIN LIKELY FOR THE
COAST...COAST RANGE AND CASCADES OVER ABOUT A 12 HR PERIOD ENDING
TONIGHT. THE INTERIOR LOWLANDS WILL BE CLOSER TO AN INCH. IT DOES NOT
APPEAR THAT RAINFALL TOTALS WILL BE ENOUGH TO CAUSE ANY FLOODING
CONCERNS.

SNOW LEVELS WILL INCREASE ABOVE ALL BUT THE HIGHEST PEAKS IN
THE AREA TODAY WITH THE WARM FRONT. SNOW LEVELS WILL CRASH
TO AROUND 3000 TO 4000 FT SATURDAY MORNING. OROGRAPHICS BECOME
FAVORABLE IN THIS COLDER AIR MASS. 850 MB WINDS ARE WESTERLY 25 TO
45 KT SAT ALONG WITH ABUNDANT SHOWERS. SNOW WILL BE HEAVIER AT TIMES
AS IMPULSES MOVE THROUGH. IT APPEARS THE PERIOD OF HIGHER SNOWFALL
ACCUMULATION WILL BE SAT INTO EARLY SUN. THIS PERIOD MAY END UP
NEEDING A WINTER WEATHER ADVISORY.  CURRENT SPECIAL WEATHER
STATEMENT COVERS THIS UNTIL THEN.

500 MB TEMPERATURES DROP TO AROUND -25 TO -30 C ON SATURDAY. LIFTED
INDEX LOWERS TO AROUND 0 TO -2. THERE IS ALSO A WEAK VORT MAX THAT
MOVES THROUGH DURING THE DAY TO ASSIST IN THE INSTABILITY. SO HAVE
ADDED A SLIGHT CHANCE OF THUNDERSTORMS OVER THE WATERS AND INLAND TO
THE COAST RANGE. THE INTERIOR LOWLAND MAY NEED TO BE ADDED AS
WELL...BUT THREAT APPEARS TOO LOW AT THIS TIME. PYLE/26


.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY. THE MORE WESTERLY OR
ZONAL FLOW THAT SETS UP OVER THE WEEKEND DURING THE LATTER PART OF
THE SHORT TERM PERIOD BEGINS TO BUCKLE A BIT IN THE EARLY PART OF
THE LONG TERM PERIOD WITH SOME FLAT RIDGING DEVELOPING OVER THE
NORTHEAST PACIFIC. HAVE DECIDED TO CONTINUE TO STICK MORE WITH A
DIRTY RIDGE SCENARIO OF THE ECMWF VS THE HIGHER AMPLITUDE RIDGING OF
THE OPERATIONAL GFS MODEL. CONFIDENCE DECREASES THROUGHOUT THE LONG
TERM PERIOD AS MODEL VARIABILITY INCREASES...THOUGH THE TREND IS
TOWARD DRIER DURING THE MIDDLE TO LATTER PARTS OF NEXT WEEK. TOLLESON

&&

.AVIATION...MIX OF VFR AND MVFR CIGS TO CONTINUE THIS MORNING AS
WARM FRONT LIFTS ACROSS THE AREA. WINDS WILL PICK UP FROM THE
SOUTH BEHIND THIS FRONT...LIFTING MOST THE AREA TO VFR CIGS. MAY
BE SOME SPEED SHEAR JUST ABOVE THE GROUND...AS SOUTHERLIES
INCREASE FROM 10 TO 30 OR 40 KTS BELOW FL030. EXPECT MIX OF VFR
AND MVFR TO PERSIST ACROSS THE AREA...THOUGH STRONG LOW-LEVEL
WINDS MAY KEEP CIGS MAINLY VFR. COLD FRONT MOVES THROUGH AROUND
06Z TO 09Z WHICH WILL ALLOW WINDS TO DIE DOWN THIS
EVENING...BRINGING CIGS BACK DOWN TO MVFR AND SOME IFR TONIGHT.

KPDX AND APPROACHES...VFR CONTINUES THROUGH THIS MORNING...THOUGH
HEAVIER SHOWERS MAY CAUSE OCCASIONAL MVFR CIGS. SOUTHERLIES
INCREASE FROM 10 KTS AT THE SURFACE TO 30 OR 40 KTS BELOW FL030
THIS AFTERNOON...BUT WILL DECREASE BEHIND COLD FRONT AROUND 06Z TO
09Z THIS EVENING.

-MCCOY

&&

.MARINE...GALE WARNING IN EFFECT THROUGH THIS EVENING. SOUTHERLY
WINDS CURRENTLY 20 TO 25 KTS GUSTING TO 35 CURRENTLY...AND WILL
CONTINUE TO RAMP UP THROUGH THIS AFTERNOON. EXPECTING SOLID GALES
WITH SOME STORM FORCE GUSTS POSSIBLE...MAINLY IN THE INNER WATERS
WITH A COASTAL JET. STRONGEST WINDS WILL OCCUR DURING THE
AFTERNOON HOURS...BEFORE DECREASING THIS EVENING BEHIND THE COLD
FRONT.

SEAS 10 TO 12 FT THIS MORNING WILL BUILD QUICKLY THIS AFTERNOON TO
NEAR 20 FT BY 4-6PM THIS EVENING. SEAS WILL SUBSIDE BEHIND THE
FRONT...DROPPING TO 12 TO 14 FT BY MIDNIGHT. SMALL CRAFT ADVISORY
SEAS ABOVE 10 FT LOOK TO PERSIST THROUGH THIS WEEKEND.

-MCCOY

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...HIGH WIND WARNING UNTIL 7 PM PST THIS EVENING FOR CENTRAL
    OREGON COAST-NORTH OREGON COAST.

WA...HIGH WIND WARNING UNTIL 7 PM PST THIS EVENING FOR SOUTH
     WASHINGTON COAST.

PZ...GALE WARNING UNTIL 10 PM PST THIS EVENING FOR COASTAL WATERS
    FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 10 PM
    PST THIS EVENING.

&&

$$

INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND

THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.


  [top]

000
FXUS66 KSEW 211730
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
930 AM PST FRI NOV 21 2014

.SYNOPSIS...A VIGOROUS FRONTAL SYSTEM WILL MOVE THROUGH WESTERN
WASHINGTON TODAY. ANOTHER FRONT WILL MOVE THROUGH THE AREA ON
SUNDAY. A WARM FRONT WILL BE OVER THE AREA MONDAY. AN UPPER RIDGE
WILL BUILD INTO THE AREA TUESDAY. THE RIDGE WILL MOVE INLAND
WEDNESDAY AND A FRONT MAY REACH THE AREA WEDNESDAY NIGHT.

&&

.SHORT TERM...A FRONTAL SYSTEM WILL MOVE THROUGH WESTERN WASHINGTON
TODAY. THE UW 4KM WRFGFS WIND FORECAST SHOWS THE FRONTAL WIND SHIFT
ON A LINE FROM THE CLM-AST AROUND 4PM. A PSCZ WIND PATTERN SETS UP
THIS EVENING AND PERSISTS ALL NIGHT IN THE WAKE OF THE FRONT WITH
SHOWERS. ANOTHER FRONT WILL MOVE THROUGH THE AREA ON SUNDAY...BUT
THE SYSTEM LOOKS WEAKER AND IS MOVING THROUGH A BROAD RIDGE THAT
STARTS TO BUILD ALONG 130W LATER THIS WEEKEND. THE GFS SHOWS WHILE
THE RIDGE BUILDS SUNDAY NIGHT AND MONDAY...A WARM FRONT SLIPS INTO
THE AREA.

.LONG TERM...THE 12Z GFS SHOWS THAT WARM FRONT OVER THE AREA MONDAY
WITH HEIGHTS RISING. THE RIDGE BUILDS FURTHER THROUGH TUESDAY WITH
500MB HEIGHTS REACH THE 570S OVER WRN WA AND THE RIDGE AXIS ALONG
THE WEST COAST TUE AFTERNOON. THE RIDGE MOVES INLAND TUE NITE AND
WED AND THE GFS SHOWS A FRONT MOVING THROUGH THE AREA WED NITE. SOME
PRECIP PERSISTS IN THE GFS ON THU...AND THEN ANOTHER SYSTEM SPLITS
OUT OF THE WESTERLIES AND MOVES MAINLY TOWARD CALIF AND OREGON
FRIDAY.

&&

.HYDROLOGY...RIVER FLOODING IS NOT EXPECTED THE NEXT 7 DAYS.

&&

.AVIATION...A COLD FRONT WILL REACH THE COAST AROUND 4 PM
TODAY...THEN PASS THE I-5 CORRIDOR ABOUT 3-4 HOURS LATER. STRONG
S-SW FLOW ALOFT TODAY IN ADVANCE OF THE FRONT...BECOMING MODERATE
WESTERLY THIS EVENING BEHIND THE FRONT. DEEP MOISTURE AND STRONG
LIFT IN THE PRE-FRONTAL ENVIRONMENT ARE LEADING TO RAIN WITH LOW
CEILINGS AND REDUCED VISIBILITY ALONG THE COAST...AND THE HEAVIER
RAIN IS SPREADING INTO THE INTERIOR OF WRN WA NOW. LOW-LEVEL WIND
SHEAR WILL INCREASE UNTIL THE COLD FRONTAL PASSAGE...MOST NOTABLY IN
PLACES WHERE SFC WINDS REMAIN LIGHT THIS AFTN. BEHIND THE FRONT THIS
EVNG...THE AIR MASS WILL BECOME UNSTABLE WITH CONVECTIVE SHOWERS
ENHANCED BY OROGRAPHIC EFFECTS.

KSEA...COLD FRONTAL PASSAGE MOST LIKELY AROUND 02Z-03Z (6-7 PM).
UNTIL THEN...RAIN WILL GENERALLY PICK UP WITH CEILINGS AND
VISIBILITIES COMING DOWN. WINDS ALOFT AT 4500 FEET MSL WILL PEAK
ARND 50-55 KT AROUND THE TIME OF FROPA. LOW-LEVEL WIND SHEAR WILL
NOT BE MENTIONED IN TAF BUT WILL BECOME A GREATER CONSIDERATION IF
SFC WINDS TAKE ON A MORE EASTERLY COMPONENT THAN FORECAST THIS AFTN.
AFTER THE COLD FRONTAL PASSAGE...SFC WINDS BECOME S-SW. HEAVIER
STRATIFORM RAIN WILL END...TURNING TO CONVECTIVE SHOWERS. CLOSEST
SHOWERS WILL BE FOCUSED IN A PUGET SOUND CONVERGENCE ZONE THAT WILL
LINGER BETWEEN EVERETT AND DOWNTOWN SEATTLE THROUGH SATURDAY AFTN.
HANER

&&

.MARINE...SE GRADIENTS WILL CONTINUE TO PICK UP UNTIL THE PASSAGE OF
A COLD FRONT LATER TODAY. THE FRONT WILL REACH THE COAST AROUND 4
PM...THEN CROSS THE INLAND WATERS ABOUT 3-4 HOURS LATER. FRONTAL
PASSAGE WILL BE ACCOMPANIED BY A SHIFT FROM S-SE WINDS TO SW-W
WINDS. STRONGEST WINDS WILL BE IN ADVANCE OF THE FRONT...WITH GALE
WARNINGS NOW IN EFFECT FOR THE COASTAL WATERS...THE EAST
ENTRANCE...ADMIRALTY INLET...AND THE NORTHERN INLAND WATERS. SMALL
CRAFT ADVISORIES ARE IN EFFECT ELSEWHERE. A WESTERLY PUSH BEHIND THE
FRONT WILL PRODUCE SMALL CRAFT ADVISORY WEST WINDS THROUGH THE
STRAIT...THOUGH A BRIEF GALE IS ALSO POSSIBLE.

ANOTHER SYSTEM ON SUNDAY IS GAINING STRENGTH IN THE MODELS. THIS
COULD GIVE GALES ON THE COAST AND DOWN THE STRAIT. SWELLS IN THE
15-20 FOOT RANGE ARE FORECAST TO REACH THE COAST SUNDAY.    HANER

&&


.SEW WATCHES/WARNINGS/ADVISORIES...
WA...WIND ADVISORIES ARE IN EFFECT FOR THE COAST AND PARTS OF THE
     NORTHWEST INTERIOR.

     WINTER WEATHER ADVISORY IN EFFECT FOR THE CASCADES ABOVE 3500
     FEET FROM 10 AM UNTIL 6 AM SATURDAY.

PZ...GALE WARNING COAST...EAST ENTRANCE...ADMIRALTY INLET...
     AND NORTHERN INLAND WATERS.
     SMALL CRAFT ADVISORY ALL REMAINING WATERS.
     SMALL CRAFT ADVISORY FOR ROUGH GRAYS HARBOR BAR.

&&

$$

WWW.WEATHER.GOV/SEATTLE

YOU CAN SEE AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML









000
FXUS66 KSEW 211313 CCA
AFDSEW

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE SEATTLE WA
512 AM PST FRI NOV 21 2014

CORRECTED THE LONG TERM SEGMENT.

.SYNOPSIS...A STRONG PACIFIC STORM WILL BRING GUSTY WINDS TO THE
AREA AND SNOW TO THE MOUNTAINS THROUGH TONIGHT. EXPECT THE
OCCLUDED FRONT TO SWEEP ACROSS THE REGION LATE TODAY THROUGH THIS
EVENING. UNSETTLED CONDITIONS WILL PREVAIL ON SATURDAY. ALAS...
ANOTHER LOW PRESSURE SYSTEM WILL IMPACT THE AREA ON SUNDAY FOR
MORE SNOW IN THE MOUNTAINS AND LOCALLY GUSTY WINDS.

&&

.SHORT TERM...
PRECIP WAS STARTING TO INCREASE ACROSS THE CWA AHEAD OF THE MAIN
PRECIP SHIELD THAT WAS STILL OFFSHORE AT THIS TIME. SATELLITE
DERIVED PRECIPITABLE WATER /PWAT/ IMAGERY SHOWED THAT THE VIGOROUS
PACIFIC STORM APPROACHING THE PACIFIC NORTHWEST HAS A DECENT
MOISTURE FEED OR PLUME ASSOCIATED WITH IT. THE SATELLITE DERIVED
PERCENT OF NORMAL TOTAL PRECIPITABLE WATER PRODUCT SHOWED THAT
THERE WERE AMOUNTS OVER 200 PERCENT OF NORMAL ASSOCIATED WITH THE
UPCOMING SYSTEM.

THE HEAVIEST PRECIP IS EXPECTED TO FALL ON THE COAST AND IN THE
MOUNTAINS...WHERE TOTAL LIQUID PRECIP AMOUNTS ARE EXPECTED TO BE
IN THE 1 TO 2.5 INCH RANGE DURING THE 24 HOUR PERIOD ENDING AT 4
AM PST SATURDAY. THE CASCADES ABOVE THE 3500 FOOT LEVEL IS
EXPECTED TO RECEIVE 10 TO 16 INCHES OF NEW SNOW BY SATURDAY
MORNING.

STRONG WESTERLY WINDS WILL ALSO HELP TO ENHANCE SNOWFALL AMOUNTS
IN THE CASCADES...SO THERE WILL LIKELY BE LOCALIZED HIGHER
AMOUNTS. ALSO...A PUGET SOUND CONVERGENCE ZONE /PSCZ/ IS EXPECTED
TO DEVELOP LATE TONIGHT OR EARLY SATURDAY AND THIS WILL RESULT
IN LOCALLY HEAVY SNOW IN THE CASCADES NEAR THE KING/SNOHOMISH
COUNTY LINE. THE SNOW LEVELS WILL BRIEFLY RISE LATER TODAY OR
EARLY THIS EVENING BEFORE PLUMMETING TO NEAR 3000 FEET EARLY
SATURDAY. WILL NEED TO KEEP AN EYE ON EXACTLY WHERE THE PSCZ WILL
FORM BECAUSE THERE IS A DISTINCT POSSIBILITY THAT SNOQUALMIE PASS
COULD RECEIVE LOW END ADVISORY CRITERIA SNOWFALL AMOUNTS /6 OR 7
INCHES/ ON SATURDAY.

OTHER THAN THE SNOW IN THE MOUNTAINS...ANTICIPATE GUSTY WINDS
AHEAD OF AND WITH THE OCCLUDED FRONT THAT WILL SWEEP ACROSS LATE
TODAY THROUGH THIS EVENING. A WIND ADVISORY WAS ISSUED FOR THE
MORE WIND PRONE AREAS...NAMELY THE COAST AND PARTS OF THE
NORTHWEST INTERIOR.

THE UPPER TROF WILL MOVE ACROSS THE REGION SATURDAY MORNING BUT
EMBEDDED DISTURBANCES WITHIN THE STRONG WESTERLY FLOW WILL SERVE
TO KEEP WEATHER CONDITIONS UNSETTLED ACROSS THE CWA ON SATURDAY.
THE BEST CHANCE OF PRECIP WILL BE OVER THE MOUNTAINS...COAST...AND
WITHIN THE PSCZ.

THERE MAY BE A BRIEF BREAK IN THE ACTION SATURDAY EVENING BETWEEN
SYSTEMS BUT CANNOT COMPLETELY COUNT ON IT. THE NEXT SYSTEM WILL
QUICKLY FOLLOW ON THE HEELS OF THE DEPARTING ONE...WITH STEADY
PRECIP REDEVELOPING SATURDAY NIGHT. THIS NEXT SYSTEM WILL BE A
FAST ONE...THUS EXPECT THE COLD OR OCCLUDED FRONT TO SWEEP ACROSS
THE CWA LATE SUNDAY MORNING OR EARLY SUNDAY AFTERNOON. SHOWERY
CONDITIONS SHOULD PREVAIL SUNDAY AFTERNOON IN THE WAKE OF THE
FRONT. THE CASCADES ABOVE 3500 FEET CAN EXPECT TO RECEIVE ANOTHER
9 TO 15 INCHES OF NEW SNOW FROM THIS SYSTEM.

.LONG TERM...
CONFIDENCE IN THIS PERIOD WAS NOT HIGH DUE TO LACK OF AGREEMENT
BETWEEN THE MEDIUM RANGE SOLUTIONS AS WELL AS LACK OF RUN TO RUN
CONSISTENCY IN THE MODELS. EITHER THERE WILL BE AN UPPER TROF OVER
THE REGION ON WED OR AN UPPER RIDGE. DECIDED TO LEAVE THE INHERITED
FORECAST PRETTY MUCH INTACT.

&&

.HYDROLOGY...
RIVER FLOODING IS NOT EXPECTED THE NEXT 7 DAYS.

&&

.AVIATION...WESTERLY FLOW ALOFT AS A STRONG FRONTAL SYSTEM
APPROACHES THE COAST. THE AIR MASS IS MOIST AND STABLE EXCEPT FOR
ISOLATED SHOWERS NORTH PART. RAIN FROM THE APPROACHING FRONT WILL
SPREAD INLAND AROUND 15Z. THE FRONT WILL REACH THE COAST AROUND 00Z
AND PUGET SOUND AROUND 04Z. AT THE SURFACE STRONG GUSTY SOUTHEAST
WINDS WILL DEVELOP ALONG THE COAST AND OVER PARTS OF THE NORTH
INTERIOR THIS AFTERNOON AND CONTINUE INTO THE EVENING.

CEILINGS ARE GENERALLY VFR 4K-6K FT. CEILINGS WILL FALL TO MVFR
2K-3K FT IN RAIN 12Z-15Z AND STAY THERE ALL DAY. CEILINGS WILL NOT
IMPROVE MUCH TONIGHT IN ONSHORE SURFACE FLOW AND A SHOWERY PATTERN.

KSEA...DISCUSSION ABOVE APPLIES. WINDS SOUTHEAST 5-9 KT. RAIN AND
MVFR CONDITIONS WILL PREDOMINATE TODAY. WINDS WILL RISE TO SOUTHERLY
8-12 KT IN THE AFTERNOON. CHB

&&

.MARINE...A STRONG FRONTAL SYSTEM WILL MOVE THROUGH THE AREA TODAY.
GALE WARNINGS ARE UP FOR THE COASTAL WATERS AND THE EAST ENTRANCE
AND NORTH INLAND WATERS WITH SMALL CRAFT ADVISORIES ELSEWHERE.
FRONTAL PASSAGE ALONG THE COAST SHOULD BE AROUND 00Z...THEN AROUND
04Z OVER PUGET SOUND. A WESTERLY PUSH BEHIND THE FRONT WILL PRODUCE
SMALL CRAFT ADVISORY WEST WINDS THROUGH THE STRAIT...THOUGH A BRIEF
GALE IS ALSO POSSIBLE.

ANOTHER SYSTEM ON SUNDAY IS GAINING STRENGTH IN THE MODELS. THIS
COULD GIVE GALES ON THE COAST AND DOWN THE STRAIT. SWELLS IN THE
15-20 FOOT RANGE ARE FORECAST TO REACH THE COAST SUNDAY. CHB

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...WIND ADVISORIES ARE IN EFFECT FOR THE COAST AND PARTS OF THE
     NORTHWEST INTERIOR.

     WINTER WEATHER ADVISORY IN EFFECT FOR THE CASCADES ABOVE 3500
     FEET FROM 10 AM UNTIL 6 AM SATURDAY.

PZ...GALE WARNING IN EFFECT UNTIL 10 PM TONIGHT FOR THE COASTAL
     WATERS...EAST ENTRANCE TO THE STRAIT OF JUAN DE FUCA...AND
     THE NORTHERN INLAND WATERS.

     SMALL CRAFT ADVISORIES ARE IN EFFECT FOR THE REMAINING WATERS.

     SMALL CRAFT ADVISORY IN EFFECT FOR ROUGH BAR UNTIL 10 AM
     SATURDAY FOR THE GRAYS HARBOR BAR.

&&

$$

WWW.WEATHER.GOV/SEATTLE

YOU CAN SEE AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML





000
FXUS66 KSEW 211313 CCA
AFDSEW

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE SEATTLE WA
512 AM PST FRI NOV 21 2014

CORRECTED THE LONG TERM SEGMENT.

.SYNOPSIS...A STRONG PACIFIC STORM WILL BRING GUSTY WINDS TO THE
AREA AND SNOW TO THE MOUNTAINS THROUGH TONIGHT. EXPECT THE
OCCLUDED FRONT TO SWEEP ACROSS THE REGION LATE TODAY THROUGH THIS
EVENING. UNSETTLED CONDITIONS WILL PREVAIL ON SATURDAY. ALAS...
ANOTHER LOW PRESSURE SYSTEM WILL IMPACT THE AREA ON SUNDAY FOR
MORE SNOW IN THE MOUNTAINS AND LOCALLY GUSTY WINDS.

&&

.SHORT TERM...
PRECIP WAS STARTING TO INCREASE ACROSS THE CWA AHEAD OF THE MAIN
PRECIP SHIELD THAT WAS STILL OFFSHORE AT THIS TIME. SATELLITE
DERIVED PRECIPITABLE WATER /PWAT/ IMAGERY SHOWED THAT THE VIGOROUS
PACIFIC STORM APPROACHING THE PACIFIC NORTHWEST HAS A DECENT
MOISTURE FEED OR PLUME ASSOCIATED WITH IT. THE SATELLITE DERIVED
PERCENT OF NORMAL TOTAL PRECIPITABLE WATER PRODUCT SHOWED THAT
THERE WERE AMOUNTS OVER 200 PERCENT OF NORMAL ASSOCIATED WITH THE
UPCOMING SYSTEM.

THE HEAVIEST PRECIP IS EXPECTED TO FALL ON THE COAST AND IN THE
MOUNTAINS...WHERE TOTAL LIQUID PRECIP AMOUNTS ARE EXPECTED TO BE
IN THE 1 TO 2.5 INCH RANGE DURING THE 24 HOUR PERIOD ENDING AT 4
AM PST SATURDAY. THE CASCADES ABOVE THE 3500 FOOT LEVEL IS
EXPECTED TO RECEIVE 10 TO 16 INCHES OF NEW SNOW BY SATURDAY
MORNING.

STRONG WESTERLY WINDS WILL ALSO HELP TO ENHANCE SNOWFALL AMOUNTS
IN THE CASCADES...SO THERE WILL LIKELY BE LOCALIZED HIGHER
AMOUNTS. ALSO...A PUGET SOUND CONVERGENCE ZONE /PSCZ/ IS EXPECTED
TO DEVELOP LATE TONIGHT OR EARLY SATURDAY AND THIS WILL RESULT
IN LOCALLY HEAVY SNOW IN THE CASCADES NEAR THE KING/SNOHOMISH
COUNTY LINE. THE SNOW LEVELS WILL BRIEFLY RISE LATER TODAY OR
EARLY THIS EVENING BEFORE PLUMMETING TO NEAR 3000 FEET EARLY
SATURDAY. WILL NEED TO KEEP AN EYE ON EXACTLY WHERE THE PSCZ WILL
FORM BECAUSE THERE IS A DISTINCT POSSIBILITY THAT SNOQUALMIE PASS
COULD RECEIVE LOW END ADVISORY CRITERIA SNOWFALL AMOUNTS /6 OR 7
INCHES/ ON SATURDAY.

OTHER THAN THE SNOW IN THE MOUNTAINS...ANTICIPATE GUSTY WINDS
AHEAD OF AND WITH THE OCCLUDED FRONT THAT WILL SWEEP ACROSS LATE
TODAY THROUGH THIS EVENING. A WIND ADVISORY WAS ISSUED FOR THE
MORE WIND PRONE AREAS...NAMELY THE COAST AND PARTS OF THE
NORTHWEST INTERIOR.

THE UPPER TROF WILL MOVE ACROSS THE REGION SATURDAY MORNING BUT
EMBEDDED DISTURBANCES WITHIN THE STRONG WESTERLY FLOW WILL SERVE
TO KEEP WEATHER CONDITIONS UNSETTLED ACROSS THE CWA ON SATURDAY.
THE BEST CHANCE OF PRECIP WILL BE OVER THE MOUNTAINS...COAST...AND
WITHIN THE PSCZ.

THERE MAY BE A BRIEF BREAK IN THE ACTION SATURDAY EVENING BETWEEN
SYSTEMS BUT CANNOT COMPLETELY COUNT ON IT. THE NEXT SYSTEM WILL
QUICKLY FOLLOW ON THE HEELS OF THE DEPARTING ONE...WITH STEADY
PRECIP REDEVELOPING SATURDAY NIGHT. THIS NEXT SYSTEM WILL BE A
FAST ONE...THUS EXPECT THE COLD OR OCCLUDED FRONT TO SWEEP ACROSS
THE CWA LATE SUNDAY MORNING OR EARLY SUNDAY AFTERNOON. SHOWERY
CONDITIONS SHOULD PREVAIL SUNDAY AFTERNOON IN THE WAKE OF THE
FRONT. THE CASCADES ABOVE 3500 FEET CAN EXPECT TO RECEIVE ANOTHER
9 TO 15 INCHES OF NEW SNOW FROM THIS SYSTEM.

.LONG TERM...
CONFIDENCE IN THIS PERIOD WAS NOT HIGH DUE TO LACK OF AGREEMENT
BETWEEN THE MEDIUM RANGE SOLUTIONS AS WELL AS LACK OF RUN TO RUN
CONSISTENCY IN THE MODELS. EITHER THERE WILL BE AN UPPER TROF OVER
THE REGION ON WED OR AN UPPER RIDGE. DECIDED TO LEAVE THE INHERITED
FORECAST PRETTY MUCH INTACT.

&&

.HYDROLOGY...
RIVER FLOODING IS NOT EXPECTED THE NEXT 7 DAYS.

&&

.AVIATION...WESTERLY FLOW ALOFT AS A STRONG FRONTAL SYSTEM
APPROACHES THE COAST. THE AIR MASS IS MOIST AND STABLE EXCEPT FOR
ISOLATED SHOWERS NORTH PART. RAIN FROM THE APPROACHING FRONT WILL
SPREAD INLAND AROUND 15Z. THE FRONT WILL REACH THE COAST AROUND 00Z
AND PUGET SOUND AROUND 04Z. AT THE SURFACE STRONG GUSTY SOUTHEAST
WINDS WILL DEVELOP ALONG THE COAST AND OVER PARTS OF THE NORTH
INTERIOR THIS AFTERNOON AND CONTINUE INTO THE EVENING.

CEILINGS ARE GENERALLY VFR 4K-6K FT. CEILINGS WILL FALL TO MVFR
2K-3K FT IN RAIN 12Z-15Z AND STAY THERE ALL DAY. CEILINGS WILL NOT
IMPROVE MUCH TONIGHT IN ONSHORE SURFACE FLOW AND A SHOWERY PATTERN.

KSEA...DISCUSSION ABOVE APPLIES. WINDS SOUTHEAST 5-9 KT. RAIN AND
MVFR CONDITIONS WILL PREDOMINATE TODAY. WINDS WILL RISE TO SOUTHERLY
8-12 KT IN THE AFTERNOON. CHB

&&

.MARINE...A STRONG FRONTAL SYSTEM WILL MOVE THROUGH THE AREA TODAY.
GALE WARNINGS ARE UP FOR THE COASTAL WATERS AND THE EAST ENTRANCE
AND NORTH INLAND WATERS WITH SMALL CRAFT ADVISORIES ELSEWHERE.
FRONTAL PASSAGE ALONG THE COAST SHOULD BE AROUND 00Z...THEN AROUND
04Z OVER PUGET SOUND. A WESTERLY PUSH BEHIND THE FRONT WILL PRODUCE
SMALL CRAFT ADVISORY WEST WINDS THROUGH THE STRAIT...THOUGH A BRIEF
GALE IS ALSO POSSIBLE.

ANOTHER SYSTEM ON SUNDAY IS GAINING STRENGTH IN THE MODELS. THIS
COULD GIVE GALES ON THE COAST AND DOWN THE STRAIT. SWELLS IN THE
15-20 FOOT RANGE ARE FORECAST TO REACH THE COAST SUNDAY. CHB

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...WIND ADVISORIES ARE IN EFFECT FOR THE COAST AND PARTS OF THE
     NORTHWEST INTERIOR.

     WINTER WEATHER ADVISORY IN EFFECT FOR THE CASCADES ABOVE 3500
     FEET FROM 10 AM UNTIL 6 AM SATURDAY.

PZ...GALE WARNING IN EFFECT UNTIL 10 PM TONIGHT FOR THE COASTAL
     WATERS...EAST ENTRANCE TO THE STRAIT OF JUAN DE FUCA...AND
     THE NORTHERN INLAND WATERS.

     SMALL CRAFT ADVISORIES ARE IN EFFECT FOR THE REMAINING WATERS.

     SMALL CRAFT ADVISORY IN EFFECT FOR ROUGH BAR UNTIL 10 AM
     SATURDAY FOR THE GRAYS HARBOR BAR.

&&

$$

WWW.WEATHER.GOV/SEATTLE

YOU CAN SEE AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML





000
FXUS66 KSEW 211313 CCA
AFDSEW

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE SEATTLE WA
512 AM PST FRI NOV 21 2014

CORRECTED THE LONG TERM SEGMENT.

.SYNOPSIS...A STRONG PACIFIC STORM WILL BRING GUSTY WINDS TO THE
AREA AND SNOW TO THE MOUNTAINS THROUGH TONIGHT. EXPECT THE
OCCLUDED FRONT TO SWEEP ACROSS THE REGION LATE TODAY THROUGH THIS
EVENING. UNSETTLED CONDITIONS WILL PREVAIL ON SATURDAY. ALAS...
ANOTHER LOW PRESSURE SYSTEM WILL IMPACT THE AREA ON SUNDAY FOR
MORE SNOW IN THE MOUNTAINS AND LOCALLY GUSTY WINDS.

&&

.SHORT TERM...
PRECIP WAS STARTING TO INCREASE ACROSS THE CWA AHEAD OF THE MAIN
PRECIP SHIELD THAT WAS STILL OFFSHORE AT THIS TIME. SATELLITE
DERIVED PRECIPITABLE WATER /PWAT/ IMAGERY SHOWED THAT THE VIGOROUS
PACIFIC STORM APPROACHING THE PACIFIC NORTHWEST HAS A DECENT
MOISTURE FEED OR PLUME ASSOCIATED WITH IT. THE SATELLITE DERIVED
PERCENT OF NORMAL TOTAL PRECIPITABLE WATER PRODUCT SHOWED THAT
THERE WERE AMOUNTS OVER 200 PERCENT OF NORMAL ASSOCIATED WITH THE
UPCOMING SYSTEM.

THE HEAVIEST PRECIP IS EXPECTED TO FALL ON THE COAST AND IN THE
MOUNTAINS...WHERE TOTAL LIQUID PRECIP AMOUNTS ARE EXPECTED TO BE
IN THE 1 TO 2.5 INCH RANGE DURING THE 24 HOUR PERIOD ENDING AT 4
AM PST SATURDAY. THE CASCADES ABOVE THE 3500 FOOT LEVEL IS
EXPECTED TO RECEIVE 10 TO 16 INCHES OF NEW SNOW BY SATURDAY
MORNING.

STRONG WESTERLY WINDS WILL ALSO HELP TO ENHANCE SNOWFALL AMOUNTS
IN THE CASCADES...SO THERE WILL LIKELY BE LOCALIZED HIGHER
AMOUNTS. ALSO...A PUGET SOUND CONVERGENCE ZONE /PSCZ/ IS EXPECTED
TO DEVELOP LATE TONIGHT OR EARLY SATURDAY AND THIS WILL RESULT
IN LOCALLY HEAVY SNOW IN THE CASCADES NEAR THE KING/SNOHOMISH
COUNTY LINE. THE SNOW LEVELS WILL BRIEFLY RISE LATER TODAY OR
EARLY THIS EVENING BEFORE PLUMMETING TO NEAR 3000 FEET EARLY
SATURDAY. WILL NEED TO KEEP AN EYE ON EXACTLY WHERE THE PSCZ WILL
FORM BECAUSE THERE IS A DISTINCT POSSIBILITY THAT SNOQUALMIE PASS
COULD RECEIVE LOW END ADVISORY CRITERIA SNOWFALL AMOUNTS /6 OR 7
INCHES/ ON SATURDAY.

OTHER THAN THE SNOW IN THE MOUNTAINS...ANTICIPATE GUSTY WINDS
AHEAD OF AND WITH THE OCCLUDED FRONT THAT WILL SWEEP ACROSS LATE
TODAY THROUGH THIS EVENING. A WIND ADVISORY WAS ISSUED FOR THE
MORE WIND PRONE AREAS...NAMELY THE COAST AND PARTS OF THE
NORTHWEST INTERIOR.

THE UPPER TROF WILL MOVE ACROSS THE REGION SATURDAY MORNING BUT
EMBEDDED DISTURBANCES WITHIN THE STRONG WESTERLY FLOW WILL SERVE
TO KEEP WEATHER CONDITIONS UNSETTLED ACROSS THE CWA ON SATURDAY.
THE BEST CHANCE OF PRECIP WILL BE OVER THE MOUNTAINS...COAST...AND
WITHIN THE PSCZ.

THERE MAY BE A BRIEF BREAK IN THE ACTION SATURDAY EVENING BETWEEN
SYSTEMS BUT CANNOT COMPLETELY COUNT ON IT. THE NEXT SYSTEM WILL
QUICKLY FOLLOW ON THE HEELS OF THE DEPARTING ONE...WITH STEADY
PRECIP REDEVELOPING SATURDAY NIGHT. THIS NEXT SYSTEM WILL BE A
FAST ONE...THUS EXPECT THE COLD OR OCCLUDED FRONT TO SWEEP ACROSS
THE CWA LATE SUNDAY MORNING OR EARLY SUNDAY AFTERNOON. SHOWERY
CONDITIONS SHOULD PREVAIL SUNDAY AFTERNOON IN THE WAKE OF THE
FRONT. THE CASCADES ABOVE 3500 FEET CAN EXPECT TO RECEIVE ANOTHER
9 TO 15 INCHES OF NEW SNOW FROM THIS SYSTEM.

.LONG TERM...
CONFIDENCE IN THIS PERIOD WAS NOT HIGH DUE TO LACK OF AGREEMENT
BETWEEN THE MEDIUM RANGE SOLUTIONS AS WELL AS LACK OF RUN TO RUN
CONSISTENCY IN THE MODELS. EITHER THERE WILL BE AN UPPER TROF OVER
THE REGION ON WED OR AN UPPER RIDGE. DECIDED TO LEAVE THE INHERITED
FORECAST PRETTY MUCH INTACT.

&&

.HYDROLOGY...
RIVER FLOODING IS NOT EXPECTED THE NEXT 7 DAYS.

&&

.AVIATION...WESTERLY FLOW ALOFT AS A STRONG FRONTAL SYSTEM
APPROACHES THE COAST. THE AIR MASS IS MOIST AND STABLE EXCEPT FOR
ISOLATED SHOWERS NORTH PART. RAIN FROM THE APPROACHING FRONT WILL
SPREAD INLAND AROUND 15Z. THE FRONT WILL REACH THE COAST AROUND 00Z
AND PUGET SOUND AROUND 04Z. AT THE SURFACE STRONG GUSTY SOUTHEAST
WINDS WILL DEVELOP ALONG THE COAST AND OVER PARTS OF THE NORTH
INTERIOR THIS AFTERNOON AND CONTINUE INTO THE EVENING.

CEILINGS ARE GENERALLY VFR 4K-6K FT. CEILINGS WILL FALL TO MVFR
2K-3K FT IN RAIN 12Z-15Z AND STAY THERE ALL DAY. CEILINGS WILL NOT
IMPROVE MUCH TONIGHT IN ONSHORE SURFACE FLOW AND A SHOWERY PATTERN.

KSEA...DISCUSSION ABOVE APPLIES. WINDS SOUTHEAST 5-9 KT. RAIN AND
MVFR CONDITIONS WILL PREDOMINATE TODAY. WINDS WILL RISE TO SOUTHERLY
8-12 KT IN THE AFTERNOON. CHB

&&

.MARINE...A STRONG FRONTAL SYSTEM WILL MOVE THROUGH THE AREA TODAY.
GALE WARNINGS ARE UP FOR THE COASTAL WATERS AND THE EAST ENTRANCE
AND NORTH INLAND WATERS WITH SMALL CRAFT ADVISORIES ELSEWHERE.
FRONTAL PASSAGE ALONG THE COAST SHOULD BE AROUND 00Z...THEN AROUND
04Z OVER PUGET SOUND. A WESTERLY PUSH BEHIND THE FRONT WILL PRODUCE
SMALL CRAFT ADVISORY WEST WINDS THROUGH THE STRAIT...THOUGH A BRIEF
GALE IS ALSO POSSIBLE.

ANOTHER SYSTEM ON SUNDAY IS GAINING STRENGTH IN THE MODELS. THIS
COULD GIVE GALES ON THE COAST AND DOWN THE STRAIT. SWELLS IN THE
15-20 FOOT RANGE ARE FORECAST TO REACH THE COAST SUNDAY. CHB

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...WIND ADVISORIES ARE IN EFFECT FOR THE COAST AND PARTS OF THE
     NORTHWEST INTERIOR.

     WINTER WEATHER ADVISORY IN EFFECT FOR THE CASCADES ABOVE 3500
     FEET FROM 10 AM UNTIL 6 AM SATURDAY.

PZ...GALE WARNING IN EFFECT UNTIL 10 PM TONIGHT FOR THE COASTAL
     WATERS...EAST ENTRANCE TO THE STRAIT OF JUAN DE FUCA...AND
     THE NORTHERN INLAND WATERS.

     SMALL CRAFT ADVISORIES ARE IN EFFECT FOR THE REMAINING WATERS.

     SMALL CRAFT ADVISORY IN EFFECT FOR ROUGH BAR UNTIL 10 AM
     SATURDAY FOR THE GRAYS HARBOR BAR.

&&

$$

WWW.WEATHER.GOV/SEATTLE

YOU CAN SEE AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML





000
FXUS66 KSEW 211313 CCA
AFDSEW

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE SEATTLE WA
512 AM PST FRI NOV 21 2014

CORRECTED THE LONG TERM SEGMENT.

.SYNOPSIS...A STRONG PACIFIC STORM WILL BRING GUSTY WINDS TO THE
AREA AND SNOW TO THE MOUNTAINS THROUGH TONIGHT. EXPECT THE
OCCLUDED FRONT TO SWEEP ACROSS THE REGION LATE TODAY THROUGH THIS
EVENING. UNSETTLED CONDITIONS WILL PREVAIL ON SATURDAY. ALAS...
ANOTHER LOW PRESSURE SYSTEM WILL IMPACT THE AREA ON SUNDAY FOR
MORE SNOW IN THE MOUNTAINS AND LOCALLY GUSTY WINDS.

&&

.SHORT TERM...
PRECIP WAS STARTING TO INCREASE ACROSS THE CWA AHEAD OF THE MAIN
PRECIP SHIELD THAT WAS STILL OFFSHORE AT THIS TIME. SATELLITE
DERIVED PRECIPITABLE WATER /PWAT/ IMAGERY SHOWED THAT THE VIGOROUS
PACIFIC STORM APPROACHING THE PACIFIC NORTHWEST HAS A DECENT
MOISTURE FEED OR PLUME ASSOCIATED WITH IT. THE SATELLITE DERIVED
PERCENT OF NORMAL TOTAL PRECIPITABLE WATER PRODUCT SHOWED THAT
THERE WERE AMOUNTS OVER 200 PERCENT OF NORMAL ASSOCIATED WITH THE
UPCOMING SYSTEM.

THE HEAVIEST PRECIP IS EXPECTED TO FALL ON THE COAST AND IN THE
MOUNTAINS...WHERE TOTAL LIQUID PRECIP AMOUNTS ARE EXPECTED TO BE
IN THE 1 TO 2.5 INCH RANGE DURING THE 24 HOUR PERIOD ENDING AT 4
AM PST SATURDAY. THE CASCADES ABOVE THE 3500 FOOT LEVEL IS
EXPECTED TO RECEIVE 10 TO 16 INCHES OF NEW SNOW BY SATURDAY
MORNING.

STRONG WESTERLY WINDS WILL ALSO HELP TO ENHANCE SNOWFALL AMOUNTS
IN THE CASCADES...SO THERE WILL LIKELY BE LOCALIZED HIGHER
AMOUNTS. ALSO...A PUGET SOUND CONVERGENCE ZONE /PSCZ/ IS EXPECTED
TO DEVELOP LATE TONIGHT OR EARLY SATURDAY AND THIS WILL RESULT
IN LOCALLY HEAVY SNOW IN THE CASCADES NEAR THE KING/SNOHOMISH
COUNTY LINE. THE SNOW LEVELS WILL BRIEFLY RISE LATER TODAY OR
EARLY THIS EVENING BEFORE PLUMMETING TO NEAR 3000 FEET EARLY
SATURDAY. WILL NEED TO KEEP AN EYE ON EXACTLY WHERE THE PSCZ WILL
FORM BECAUSE THERE IS A DISTINCT POSSIBILITY THAT SNOQUALMIE PASS
COULD RECEIVE LOW END ADVISORY CRITERIA SNOWFALL AMOUNTS /6 OR 7
INCHES/ ON SATURDAY.

OTHER THAN THE SNOW IN THE MOUNTAINS...ANTICIPATE GUSTY WINDS
AHEAD OF AND WITH THE OCCLUDED FRONT THAT WILL SWEEP ACROSS LATE
TODAY THROUGH THIS EVENING. A WIND ADVISORY WAS ISSUED FOR THE
MORE WIND PRONE AREAS...NAMELY THE COAST AND PARTS OF THE
NORTHWEST INTERIOR.

THE UPPER TROF WILL MOVE ACROSS THE REGION SATURDAY MORNING BUT
EMBEDDED DISTURBANCES WITHIN THE STRONG WESTERLY FLOW WILL SERVE
TO KEEP WEATHER CONDITIONS UNSETTLED ACROSS THE CWA ON SATURDAY.
THE BEST CHANCE OF PRECIP WILL BE OVER THE MOUNTAINS...COAST...AND
WITHIN THE PSCZ.

THERE MAY BE A BRIEF BREAK IN THE ACTION SATURDAY EVENING BETWEEN
SYSTEMS BUT CANNOT COMPLETELY COUNT ON IT. THE NEXT SYSTEM WILL
QUICKLY FOLLOW ON THE HEELS OF THE DEPARTING ONE...WITH STEADY
PRECIP REDEVELOPING SATURDAY NIGHT. THIS NEXT SYSTEM WILL BE A
FAST ONE...THUS EXPECT THE COLD OR OCCLUDED FRONT TO SWEEP ACROSS
THE CWA LATE SUNDAY MORNING OR EARLY SUNDAY AFTERNOON. SHOWERY
CONDITIONS SHOULD PREVAIL SUNDAY AFTERNOON IN THE WAKE OF THE
FRONT. THE CASCADES ABOVE 3500 FEET CAN EXPECT TO RECEIVE ANOTHER
9 TO 15 INCHES OF NEW SNOW FROM THIS SYSTEM.

.LONG TERM...
CONFIDENCE IN THIS PERIOD WAS NOT HIGH DUE TO LACK OF AGREEMENT
BETWEEN THE MEDIUM RANGE SOLUTIONS AS WELL AS LACK OF RUN TO RUN
CONSISTENCY IN THE MODELS. EITHER THERE WILL BE AN UPPER TROF OVER
THE REGION ON WED OR AN UPPER RIDGE. DECIDED TO LEAVE THE INHERITED
FORECAST PRETTY MUCH INTACT.

&&

.HYDROLOGY...
RIVER FLOODING IS NOT EXPECTED THE NEXT 7 DAYS.

&&

.AVIATION...WESTERLY FLOW ALOFT AS A STRONG FRONTAL SYSTEM
APPROACHES THE COAST. THE AIR MASS IS MOIST AND STABLE EXCEPT FOR
ISOLATED SHOWERS NORTH PART. RAIN FROM THE APPROACHING FRONT WILL
SPREAD INLAND AROUND 15Z. THE FRONT WILL REACH THE COAST AROUND 00Z
AND PUGET SOUND AROUND 04Z. AT THE SURFACE STRONG GUSTY SOUTHEAST
WINDS WILL DEVELOP ALONG THE COAST AND OVER PARTS OF THE NORTH
INTERIOR THIS AFTERNOON AND CONTINUE INTO THE EVENING.

CEILINGS ARE GENERALLY VFR 4K-6K FT. CEILINGS WILL FALL TO MVFR
2K-3K FT IN RAIN 12Z-15Z AND STAY THERE ALL DAY. CEILINGS WILL NOT
IMPROVE MUCH TONIGHT IN ONSHORE SURFACE FLOW AND A SHOWERY PATTERN.

KSEA...DISCUSSION ABOVE APPLIES. WINDS SOUTHEAST 5-9 KT. RAIN AND
MVFR CONDITIONS WILL PREDOMINATE TODAY. WINDS WILL RISE TO SOUTHERLY
8-12 KT IN THE AFTERNOON. CHB

&&

.MARINE...A STRONG FRONTAL SYSTEM WILL MOVE THROUGH THE AREA TODAY.
GALE WARNINGS ARE UP FOR THE COASTAL WATERS AND THE EAST ENTRANCE
AND NORTH INLAND WATERS WITH SMALL CRAFT ADVISORIES ELSEWHERE.
FRONTAL PASSAGE ALONG THE COAST SHOULD BE AROUND 00Z...THEN AROUND
04Z OVER PUGET SOUND. A WESTERLY PUSH BEHIND THE FRONT WILL PRODUCE
SMALL CRAFT ADVISORY WEST WINDS THROUGH THE STRAIT...THOUGH A BRIEF
GALE IS ALSO POSSIBLE.

ANOTHER SYSTEM ON SUNDAY IS GAINING STRENGTH IN THE MODELS. THIS
COULD GIVE GALES ON THE COAST AND DOWN THE STRAIT. SWELLS IN THE
15-20 FOOT RANGE ARE FORECAST TO REACH THE COAST SUNDAY. CHB

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...WIND ADVISORIES ARE IN EFFECT FOR THE COAST AND PARTS OF THE
     NORTHWEST INTERIOR.

     WINTER WEATHER ADVISORY IN EFFECT FOR THE CASCADES ABOVE 3500
     FEET FROM 10 AM UNTIL 6 AM SATURDAY.

PZ...GALE WARNING IN EFFECT UNTIL 10 PM TONIGHT FOR THE COASTAL
     WATERS...EAST ENTRANCE TO THE STRAIT OF JUAN DE FUCA...AND
     THE NORTHERN INLAND WATERS.

     SMALL CRAFT ADVISORIES ARE IN EFFECT FOR THE REMAINING WATERS.

     SMALL CRAFT ADVISORY IN EFFECT FOR ROUGH BAR UNTIL 10 AM
     SATURDAY FOR THE GRAYS HARBOR BAR.

&&

$$

WWW.WEATHER.GOV/SEATTLE

YOU CAN SEE AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML





000
FXUS66 KSEW 211312
AFDSEW

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE SEATTLE WA
512 AM PST FRI NOV 21 2014

CORRECTED THE LONG TERM SEGMENT.

.SYNOPSIS...A STRONG PACIFIC STORM WILL BRING GUSTY WINDS TO THE
AREA AND SNOW TO THE MOUNTAINS THROUGH TONIGHT. EXPECT THE
OCCLUDED FRONT TO SWEEP ACROSS THE REGION LATE TODAY THROUGH THIS
EVENING. UNSETTLED CONDITIONS WILL PREVAIL ON SATURDAY. ALAS...
ANOTHER LOW PRESSURE SYSTEM WILL IMPACT THE AREA ON SUNDAY FOR
MORE SNOW IN THE MOUNTAINS AND LOCALLY GUSTY WINDS.

&&

.SHORT TERM...
PRECIP WAS STARTING TO INCREASE ACROSS THE CWA AHEAD OF THE MAIN
PRECIP SHIELD THAT WAS STILL OFFSHORE AT THIS TIME. SATELLITE
DERIVED PRECIPITABLE WATER /PWAT/ IMAGERY SHOWED THAT THE VIGOROUS
PACIFIC STORM APPROACHING THE PACIFIC NORTHWEST HAS A DECENT
MOISTURE FEED OR PLUME ASSOCIATED WITH IT. THE SATELLITE DERIVED
PERCENT OF NORMAL TOTAL PRECIPITABLE WATER PRODUCT SHOWED THAT
THERE WERE AMOUNTS OVER 200 PERCENT OF NORMAL ASSOCIATED WITH THE
UPCOMING SYSTEM.

THE HEAVIEST PRECIP IS EXPECTED TO FALL ON THE COAST AND IN THE
MOUNTAINS...WHERE TOTAL LIQUID PRECIP AMOUNTS ARE EXPECTED TO BE
IN THE 1 TO 2.5 INCH RANGE DURING THE 24 HOUR PERIOD ENDING AT 4
AM PST SATURDAY. THE CASCADES ABOVE THE 3500 FOOT LEVEL IS
EXPECTED TO RECEIVE 10 TO 16 INCHES OF NEW SNOW BY SATURDAY
MORNING.

STRONG WESTERLY WINDS WILL ALSO HELP TO ENHANCE SNOWFALL AMOUNTS
IN THE CASCADES...SO THERE WILL LIKELY BE LOCALIZED HIGHER
AMOUNTS. ALSO...A PUGET SOUND CONVERGENCE ZONE /PSCZ/ IS EXPECTED
TO DEVELOP LATE TONIGHT OR EARLY SATURDAY AND THIS WILL RESULT
IN LOCALLY HEAVY SNOW IN THE CASCADES NEAR THE KING/SNOHOMISH
COUNTY LINE. THE SNOW LEVELS WILL BRIEFLY RISE LATER TODAY OR
EARLY THIS EVENING BEFORE PLUMMETING TO NEAR 3000 FEET EARLY
SATURDAY. WILL NEED TO KEEP AN EYE ON EXACTLY WHERE THE PSCZ WILL
FORM BECAUSE THERE IS A DISTINCT POSSIBILITY THAT SNOQUALMIE PASS
COULD RECEIVE LOW END ADVISORY CRITERIA SNOWFALL AMOUNTS /6 OR 7
INCHES/ ON SATURDAY.

OTHER THAN THE SNOW IN THE MOUNTAINS...ANTICIPATE GUSTY WINDS
AHEAD OF AND WITH THE OCCLUDED FRONT THAT WILL SWEEP ACROSS LATE
TODAY THROUGH THIS EVENING. A WIND ADVISORY WAS ISSUED FOR THE
MORE WIND PRONE AREAS...NAMELY THE COAST AND PARTS OF THE
NORTHWEST INTERIOR.

THE UPPER TROF WILL MOVE ACROSS THE REGION SATURDAY MORNING BUT
EMBEDDED DISTURBANCES WITHIN THE STRONG WESTERLY FLOW WILL SERVE
TO KEEP WEATHER CONDITIONS UNSETTLED ACROSS THE CWA ON SATURDAY.
THE BEST CHANCE OF PRECIP WILL BE OVER THE MOUNTAINS...COAST...AND
WITHIN THE PSCZ.

THERE MAY BE A BRIEF BREAK IN THE ACTION SATURDAY EVENING BETWEEN
SYSTEMS BUT CANNOT COMPLETELY COUNT ON IT. THE NEXT SYSTEM WILL
QUICKLY FOLLOW ON THE HEELS OF THE DEPARTING ONE...WITH STEADY
PRECIP REDEVELOPING SATURDAY NIGHT. THIS NEXT SYSTEM WILL BE A
FAST ONE...THUS EXPECT THE COLD OR OCCLUDED FRONT TO SWEEP ACROSS
THE CWA LATE SUNDAY MORNING OR EARLY SUNDAY AFTERNOON. SHOWERY
CONDITIONS SHOULD PREVAIL SUNDAY AFTERNOON IN THE WAKE OF THE
FRONT. THE CASCADES ABOVE 3500 FEET CAN EXPECT TO RECEIVE ANOTHER
9 TO 15 INCHES OF NEW SNOW FROM THIS SYSTEM.

.LONG TERM...
CONFIDENCE IN THIS PERIOD WAS NOT HIGH DUE TO LACK OF AGREEMENT
BETWEEN THE MEDIUM RANGE SOLUTIONS AS WELL AS LACK OF RUN TO RUN
CONSISTENCY IN THE MODELS. EITHER THERE WILL BE AN UPPER TROF OVER
THE REGION ON WED OR AN UPPER RIDGE. DECIDED TO LEAVE THE INHERITED
FORECAST PRETTY MUCH INTACT.

&&

.HYDROLOGY...
RIVER FLOODING IS NOT EXPECTED THE NEXT 7 DAYS.

&&

.AVIATION...WESTERLY FLOW ALOFT AS A STRONG FRONTAL SYSTEM
APPROACHES THE COAST. THE AIR MASS IS MOIST AND STABLE EXCEPT FOR
ISOLATED SHOWERS NORTH PART. RAIN FROM THE APPROACHING FRONT WILL
SPREAD INLAND AROUND 15Z. THE FRONT WILL REACH THE COAST AROUND 00Z
AND PUGET SOUND AROUND 04Z. AT THE SURFACE STRONG GUSTY SOUTHEAST
WINDS WILL DEVELOP ALONG THE COAST AND OVER PARTS OF THE NORTH
INTERIOR THIS AFTERNOON AND CONTINUE INTO THE EVENING.

CEILINGS ARE GENERALLY VFR 4K-6K FT. CEILINGS WILL FALL TO MVFR
2K-3K FT IN RAIN 12Z-15Z AND STAY THERE ALL DAY. CEILINGS WILL NOT
IMPROVE MUCH TONIGHT IN ONSHORE SURFACE FLOW AND A SHOWERY PATTERN.

KSEA...DISCUSSION ABOVE APPLIES. WINDS SOUTHEAST 5-9 KT. RAIN AND
MVFR CONDITIONS WILL PREDOMINATE TODAY. WINDS WILL RISE TO SOUTHERLY
8-12 KT IN THE AFTERNOON. CHB

&&

.MARINE...A STRONG FRONTAL SYSTEM WILL MOVE THROUGH THE AREA TODAY.
GALE WARNINGS ARE UP FOR THE COASTAL WATERS AND THE EAST ENTRANCE
AND NORTH INLAND WATERS WITH SMALL CRAFT ADVISORIES ELSEWHERE.
FRONTAL PASSAGE ALONG THE COAST SHOULD BE AROUND 00Z...THEN AROUND
04Z OVER PUGET SOUND. A WESTERLY PUSH BEHIND THE FRONT WILL PRODUCE
SMALL CRAFT ADVISORY WEST WINDS THROUGH THE STRAIT...THOUGH A BRIEF
GALE IS ALSO POSSIBLE.

ANOTHER SYSTEM ON SUNDAY IS GAINING STRENGTH IN THE MODELS. THIS
COULD GIVE GALES ON THE COAST AND DOWN THE STRAIT. SWELLS IN THE
15-20 FOOT RANGE ARE FORECAST TO REACH THE COAST SUNDAY. CHB

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...WIND ADVISORIES ARE IN EFFECT FOR THE COAST AND PARTS OF THE
     NORTHWEST INTERIOR.

     WINTER WEATHER ADVISORY IN EFFECT FOR THE CASCADES ABOVE 3500
     FEET FROM 10 AM UNTIL 6 AM SATURDAY.

PZ...GALE WARNING IN EFFECT UNTIL 10 PM TONIGHT FOR THE COASTAL
     WATERS...EAST ENTRANCE TO THE STRAIT OF JUAN DE FUCA...AND
     THE NORTHERN INLAND WATERS.

     SMALL CRAFT ADVISORIES ARE IN EFFECT FOR THE REMAINING WATERS.

     SMALL CRAFT ADVISORY IN EFFECT FOR ROUGH BAR UNTIL 10 AM
     SATURDAY FOR THE GRAYS HARBOR BAR.

&&

$$

WWW.WEATHER.GOV/SEATTLE

YOU CAN SEE AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML





000
FXUS66 KSEW 211312
AFDSEW

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE SEATTLE WA
512 AM PST FRI NOV 21 2014

CORRECTED THE LONG TERM SEGMENT.

.SYNOPSIS...A STRONG PACIFIC STORM WILL BRING GUSTY WINDS TO THE
AREA AND SNOW TO THE MOUNTAINS THROUGH TONIGHT. EXPECT THE
OCCLUDED FRONT TO SWEEP ACROSS THE REGION LATE TODAY THROUGH THIS
EVENING. UNSETTLED CONDITIONS WILL PREVAIL ON SATURDAY. ALAS...
ANOTHER LOW PRESSURE SYSTEM WILL IMPACT THE AREA ON SUNDAY FOR
MORE SNOW IN THE MOUNTAINS AND LOCALLY GUSTY WINDS.

&&

.SHORT TERM...
PRECIP WAS STARTING TO INCREASE ACROSS THE CWA AHEAD OF THE MAIN
PRECIP SHIELD THAT WAS STILL OFFSHORE AT THIS TIME. SATELLITE
DERIVED PRECIPITABLE WATER /PWAT/ IMAGERY SHOWED THAT THE VIGOROUS
PACIFIC STORM APPROACHING THE PACIFIC NORTHWEST HAS A DECENT
MOISTURE FEED OR PLUME ASSOCIATED WITH IT. THE SATELLITE DERIVED
PERCENT OF NORMAL TOTAL PRECIPITABLE WATER PRODUCT SHOWED THAT
THERE WERE AMOUNTS OVER 200 PERCENT OF NORMAL ASSOCIATED WITH THE
UPCOMING SYSTEM.

THE HEAVIEST PRECIP IS EXPECTED TO FALL ON THE COAST AND IN THE
MOUNTAINS...WHERE TOTAL LIQUID PRECIP AMOUNTS ARE EXPECTED TO BE
IN THE 1 TO 2.5 INCH RANGE DURING THE 24 HOUR PERIOD ENDING AT 4
AM PST SATURDAY. THE CASCADES ABOVE THE 3500 FOOT LEVEL IS
EXPECTED TO RECEIVE 10 TO 16 INCHES OF NEW SNOW BY SATURDAY
MORNING.

STRONG WESTERLY WINDS WILL ALSO HELP TO ENHANCE SNOWFALL AMOUNTS
IN THE CASCADES...SO THERE WILL LIKELY BE LOCALIZED HIGHER
AMOUNTS. ALSO...A PUGET SOUND CONVERGENCE ZONE /PSCZ/ IS EXPECTED
TO DEVELOP LATE TONIGHT OR EARLY SATURDAY AND THIS WILL RESULT
IN LOCALLY HEAVY SNOW IN THE CASCADES NEAR THE KING/SNOHOMISH
COUNTY LINE. THE SNOW LEVELS WILL BRIEFLY RISE LATER TODAY OR
EARLY THIS EVENING BEFORE PLUMMETING TO NEAR 3000 FEET EARLY
SATURDAY. WILL NEED TO KEEP AN EYE ON EXACTLY WHERE THE PSCZ WILL
FORM BECAUSE THERE IS A DISTINCT POSSIBILITY THAT SNOQUALMIE PASS
COULD RECEIVE LOW END ADVISORY CRITERIA SNOWFALL AMOUNTS /6 OR 7
INCHES/ ON SATURDAY.

OTHER THAN THE SNOW IN THE MOUNTAINS...ANTICIPATE GUSTY WINDS
AHEAD OF AND WITH THE OCCLUDED FRONT THAT WILL SWEEP ACROSS LATE
TODAY THROUGH THIS EVENING. A WIND ADVISORY WAS ISSUED FOR THE
MORE WIND PRONE AREAS...NAMELY THE COAST AND PARTS OF THE
NORTHWEST INTERIOR.

THE UPPER TROF WILL MOVE ACROSS THE REGION SATURDAY MORNING BUT
EMBEDDED DISTURBANCES WITHIN THE STRONG WESTERLY FLOW WILL SERVE
TO KEEP WEATHER CONDITIONS UNSETTLED ACROSS THE CWA ON SATURDAY.
THE BEST CHANCE OF PRECIP WILL BE OVER THE MOUNTAINS...COAST...AND
WITHIN THE PSCZ.

THERE MAY BE A BRIEF BREAK IN THE ACTION SATURDAY EVENING BETWEEN
SYSTEMS BUT CANNOT COMPLETELY COUNT ON IT. THE NEXT SYSTEM WILL
QUICKLY FOLLOW ON THE HEELS OF THE DEPARTING ONE...WITH STEADY
PRECIP REDEVELOPING SATURDAY NIGHT. THIS NEXT SYSTEM WILL BE A
FAST ONE...THUS EXPECT THE COLD OR OCCLUDED FRONT TO SWEEP ACROSS
THE CWA LATE SUNDAY MORNING OR EARLY SUNDAY AFTERNOON. SHOWERY
CONDITIONS SHOULD PREVAIL SUNDAY AFTERNOON IN THE WAKE OF THE
FRONT. THE CASCADES ABOVE 3500 FEET CAN EXPECT TO RECEIVE ANOTHER
9 TO 15 INCHES OF NEW SNOW FROM THIS SYSTEM.

.LONG TERM...
CONFIDENCE IN THIS PERIOD WAS NOT HIGH DUE TO LACK OF AGREEMENT
BETWEEN THE MEDIUM RANGE SOLUTIONS AS WELL AS LACK OF RUN TO RUN
CONSISTENCY IN THE MODELS. EITHER THERE WILL BE AN UPPER TROF OVER
THE REGION ON WED OR AN UPPER RIDGE. DECIDED TO LEAVE THE INHERITED
FORECAST PRETTY MUCH INTACT.

&&

.HYDROLOGY...
RIVER FLOODING IS NOT EXPECTED THE NEXT 7 DAYS.

&&

.AVIATION...WESTERLY FLOW ALOFT AS A STRONG FRONTAL SYSTEM
APPROACHES THE COAST. THE AIR MASS IS MOIST AND STABLE EXCEPT FOR
ISOLATED SHOWERS NORTH PART. RAIN FROM THE APPROACHING FRONT WILL
SPREAD INLAND AROUND 15Z. THE FRONT WILL REACH THE COAST AROUND 00Z
AND PUGET SOUND AROUND 04Z. AT THE SURFACE STRONG GUSTY SOUTHEAST
WINDS WILL DEVELOP ALONG THE COAST AND OVER PARTS OF THE NORTH
INTERIOR THIS AFTERNOON AND CONTINUE INTO THE EVENING.

CEILINGS ARE GENERALLY VFR 4K-6K FT. CEILINGS WILL FALL TO MVFR
2K-3K FT IN RAIN 12Z-15Z AND STAY THERE ALL DAY. CEILINGS WILL NOT
IMPROVE MUCH TONIGHT IN ONSHORE SURFACE FLOW AND A SHOWERY PATTERN.

KSEA...DISCUSSION ABOVE APPLIES. WINDS SOUTHEAST 5-9 KT. RAIN AND
MVFR CONDITIONS WILL PREDOMINATE TODAY. WINDS WILL RISE TO SOUTHERLY
8-12 KT IN THE AFTERNOON. CHB

&&

.MARINE...A STRONG FRONTAL SYSTEM WILL MOVE THROUGH THE AREA TODAY.
GALE WARNINGS ARE UP FOR THE COASTAL WATERS AND THE EAST ENTRANCE
AND NORTH INLAND WATERS WITH SMALL CRAFT ADVISORIES ELSEWHERE.
FRONTAL PASSAGE ALONG THE COAST SHOULD BE AROUND 00Z...THEN AROUND
04Z OVER PUGET SOUND. A WESTERLY PUSH BEHIND THE FRONT WILL PRODUCE
SMALL CRAFT ADVISORY WEST WINDS THROUGH THE STRAIT...THOUGH A BRIEF
GALE IS ALSO POSSIBLE.

ANOTHER SYSTEM ON SUNDAY IS GAINING STRENGTH IN THE MODELS. THIS
COULD GIVE GALES ON THE COAST AND DOWN THE STRAIT. SWELLS IN THE
15-20 FOOT RANGE ARE FORECAST TO REACH THE COAST SUNDAY. CHB

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...WIND ADVISORIES ARE IN EFFECT FOR THE COAST AND PARTS OF THE
     NORTHWEST INTERIOR.

     WINTER WEATHER ADVISORY IN EFFECT FOR THE CASCADES ABOVE 3500
     FEET FROM 10 AM UNTIL 6 AM SATURDAY.

PZ...GALE WARNING IN EFFECT UNTIL 10 PM TONIGHT FOR THE COASTAL
     WATERS...EAST ENTRANCE TO THE STRAIT OF JUAN DE FUCA...AND
     THE NORTHERN INLAND WATERS.

     SMALL CRAFT ADVISORIES ARE IN EFFECT FOR THE REMAINING WATERS.

     SMALL CRAFT ADVISORY IN EFFECT FOR ROUGH BAR UNTIL 10 AM
     SATURDAY FOR THE GRAYS HARBOR BAR.

&&

$$

WWW.WEATHER.GOV/SEATTLE

YOU CAN SEE AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML





000
FXUS66 KSEW 211312
AFDSEW

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE SEATTLE WA
512 AM PST FRI NOV 21 2014

CORRECTED THE LONG TERM SEGMENT.

.SYNOPSIS...A STRONG PACIFIC STORM WILL BRING GUSTY WINDS TO THE
AREA AND SNOW TO THE MOUNTAINS THROUGH TONIGHT. EXPECT THE
OCCLUDED FRONT TO SWEEP ACROSS THE REGION LATE TODAY THROUGH THIS
EVENING. UNSETTLED CONDITIONS WILL PREVAIL ON SATURDAY. ALAS...
ANOTHER LOW PRESSURE SYSTEM WILL IMPACT THE AREA ON SUNDAY FOR
MORE SNOW IN THE MOUNTAINS AND LOCALLY GUSTY WINDS.

&&

.SHORT TERM...
PRECIP WAS STARTING TO INCREASE ACROSS THE CWA AHEAD OF THE MAIN
PRECIP SHIELD THAT WAS STILL OFFSHORE AT THIS TIME. SATELLITE
DERIVED PRECIPITABLE WATER /PWAT/ IMAGERY SHOWED THAT THE VIGOROUS
PACIFIC STORM APPROACHING THE PACIFIC NORTHWEST HAS A DECENT
MOISTURE FEED OR PLUME ASSOCIATED WITH IT. THE SATELLITE DERIVED
PERCENT OF NORMAL TOTAL PRECIPITABLE WATER PRODUCT SHOWED THAT
THERE WERE AMOUNTS OVER 200 PERCENT OF NORMAL ASSOCIATED WITH THE
UPCOMING SYSTEM.

THE HEAVIEST PRECIP IS EXPECTED TO FALL ON THE COAST AND IN THE
MOUNTAINS...WHERE TOTAL LIQUID PRECIP AMOUNTS ARE EXPECTED TO BE
IN THE 1 TO 2.5 INCH RANGE DURING THE 24 HOUR PERIOD ENDING AT 4
AM PST SATURDAY. THE CASCADES ABOVE THE 3500 FOOT LEVEL IS
EXPECTED TO RECEIVE 10 TO 16 INCHES OF NEW SNOW BY SATURDAY
MORNING.

STRONG WESTERLY WINDS WILL ALSO HELP TO ENHANCE SNOWFALL AMOUNTS
IN THE CASCADES...SO THERE WILL LIKELY BE LOCALIZED HIGHER
AMOUNTS. ALSO...A PUGET SOUND CONVERGENCE ZONE /PSCZ/ IS EXPECTED
TO DEVELOP LATE TONIGHT OR EARLY SATURDAY AND THIS WILL RESULT
IN LOCALLY HEAVY SNOW IN THE CASCADES NEAR THE KING/SNOHOMISH
COUNTY LINE. THE SNOW LEVELS WILL BRIEFLY RISE LATER TODAY OR
EARLY THIS EVENING BEFORE PLUMMETING TO NEAR 3000 FEET EARLY
SATURDAY. WILL NEED TO KEEP AN EYE ON EXACTLY WHERE THE PSCZ WILL
FORM BECAUSE THERE IS A DISTINCT POSSIBILITY THAT SNOQUALMIE PASS
COULD RECEIVE LOW END ADVISORY CRITERIA SNOWFALL AMOUNTS /6 OR 7
INCHES/ ON SATURDAY.

OTHER THAN THE SNOW IN THE MOUNTAINS...ANTICIPATE GUSTY WINDS
AHEAD OF AND WITH THE OCCLUDED FRONT THAT WILL SWEEP ACROSS LATE
TODAY THROUGH THIS EVENING. A WIND ADVISORY WAS ISSUED FOR THE
MORE WIND PRONE AREAS...NAMELY THE COAST AND PARTS OF THE
NORTHWEST INTERIOR.

THE UPPER TROF WILL MOVE ACROSS THE REGION SATURDAY MORNING BUT
EMBEDDED DISTURBANCES WITHIN THE STRONG WESTERLY FLOW WILL SERVE
TO KEEP WEATHER CONDITIONS UNSETTLED ACROSS THE CWA ON SATURDAY.
THE BEST CHANCE OF PRECIP WILL BE OVER THE MOUNTAINS...COAST...AND
WITHIN THE PSCZ.

THERE MAY BE A BRIEF BREAK IN THE ACTION SATURDAY EVENING BETWEEN
SYSTEMS BUT CANNOT COMPLETELY COUNT ON IT. THE NEXT SYSTEM WILL
QUICKLY FOLLOW ON THE HEELS OF THE DEPARTING ONE...WITH STEADY
PRECIP REDEVELOPING SATURDAY NIGHT. THIS NEXT SYSTEM WILL BE A
FAST ONE...THUS EXPECT THE COLD OR OCCLUDED FRONT TO SWEEP ACROSS
THE CWA LATE SUNDAY MORNING OR EARLY SUNDAY AFTERNOON. SHOWERY
CONDITIONS SHOULD PREVAIL SUNDAY AFTERNOON IN THE WAKE OF THE
FRONT. THE CASCADES ABOVE 3500 FEET CAN EXPECT TO RECEIVE ANOTHER
9 TO 15 INCHES OF NEW SNOW FROM THIS SYSTEM.

.LONG TERM...
CONFIDENCE IN THIS PERIOD WAS NOT HIGH DUE TO LACK OF AGREEMENT
BETWEEN THE MEDIUM RANGE SOLUTIONS AS WELL AS LACK OF RUN TO RUN
CONSISTENCY IN THE MODELS. EITHER THERE WILL BE AN UPPER TROF OVER
THE REGION ON WED OR AN UPPER RIDGE. DECIDED TO LEAVE THE INHERITED
FORECAST PRETTY MUCH INTACT.

&&

.HYDROLOGY...
RIVER FLOODING IS NOT EXPECTED THE NEXT 7 DAYS.

&&

.AVIATION...WESTERLY FLOW ALOFT AS A STRONG FRONTAL SYSTEM
APPROACHES THE COAST. THE AIR MASS IS MOIST AND STABLE EXCEPT FOR
ISOLATED SHOWERS NORTH PART. RAIN FROM THE APPROACHING FRONT WILL
SPREAD INLAND AROUND 15Z. THE FRONT WILL REACH THE COAST AROUND 00Z
AND PUGET SOUND AROUND 04Z. AT THE SURFACE STRONG GUSTY SOUTHEAST
WINDS WILL DEVELOP ALONG THE COAST AND OVER PARTS OF THE NORTH
INTERIOR THIS AFTERNOON AND CONTINUE INTO THE EVENING.

CEILINGS ARE GENERALLY VFR 4K-6K FT. CEILINGS WILL FALL TO MVFR
2K-3K FT IN RAIN 12Z-15Z AND STAY THERE ALL DAY. CEILINGS WILL NOT
IMPROVE MUCH TONIGHT IN ONSHORE SURFACE FLOW AND A SHOWERY PATTERN.

KSEA...DISCUSSION ABOVE APPLIES. WINDS SOUTHEAST 5-9 KT. RAIN AND
MVFR CONDITIONS WILL PREDOMINATE TODAY. WINDS WILL RISE TO SOUTHERLY
8-12 KT IN THE AFTERNOON. CHB

&&

.MARINE...A STRONG FRONTAL SYSTEM WILL MOVE THROUGH THE AREA TODAY.
GALE WARNINGS ARE UP FOR THE COASTAL WATERS AND THE EAST ENTRANCE
AND NORTH INLAND WATERS WITH SMALL CRAFT ADVISORIES ELSEWHERE.
FRONTAL PASSAGE ALONG THE COAST SHOULD BE AROUND 00Z...THEN AROUND
04Z OVER PUGET SOUND. A WESTERLY PUSH BEHIND THE FRONT WILL PRODUCE
SMALL CRAFT ADVISORY WEST WINDS THROUGH THE STRAIT...THOUGH A BRIEF
GALE IS ALSO POSSIBLE.

ANOTHER SYSTEM ON SUNDAY IS GAINING STRENGTH IN THE MODELS. THIS
COULD GIVE GALES ON THE COAST AND DOWN THE STRAIT. SWELLS IN THE
15-20 FOOT RANGE ARE FORECAST TO REACH THE COAST SUNDAY. CHB

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...WIND ADVISORIES ARE IN EFFECT FOR THE COAST AND PARTS OF THE
     NORTHWEST INTERIOR.

     WINTER WEATHER ADVISORY IN EFFECT FOR THE CASCADES ABOVE 3500
     FEET FROM 10 AM UNTIL 6 AM SATURDAY.

PZ...GALE WARNING IN EFFECT UNTIL 10 PM TONIGHT FOR THE COASTAL
     WATERS...EAST ENTRANCE TO THE STRAIT OF JUAN DE FUCA...AND
     THE NORTHERN INLAND WATERS.

     SMALL CRAFT ADVISORIES ARE IN EFFECT FOR THE REMAINING WATERS.

     SMALL CRAFT ADVISORY IN EFFECT FOR ROUGH BAR UNTIL 10 AM
     SATURDAY FOR THE GRAYS HARBOR BAR.

&&

$$

WWW.WEATHER.GOV/SEATTLE

YOU CAN SEE AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML





000
FXUS66 KSEW 211312
AFDSEW

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE SEATTLE WA
512 AM PST FRI NOV 21 2014

CORRECTED THE LONG TERM SEGMENT.

.SYNOPSIS...A STRONG PACIFIC STORM WILL BRING GUSTY WINDS TO THE
AREA AND SNOW TO THE MOUNTAINS THROUGH TONIGHT. EXPECT THE
OCCLUDED FRONT TO SWEEP ACROSS THE REGION LATE TODAY THROUGH THIS
EVENING. UNSETTLED CONDITIONS WILL PREVAIL ON SATURDAY. ALAS...
ANOTHER LOW PRESSURE SYSTEM WILL IMPACT THE AREA ON SUNDAY FOR
MORE SNOW IN THE MOUNTAINS AND LOCALLY GUSTY WINDS.

&&

.SHORT TERM...
PRECIP WAS STARTING TO INCREASE ACROSS THE CWA AHEAD OF THE MAIN
PRECIP SHIELD THAT WAS STILL OFFSHORE AT THIS TIME. SATELLITE
DERIVED PRECIPITABLE WATER /PWAT/ IMAGERY SHOWED THAT THE VIGOROUS
PACIFIC STORM APPROACHING THE PACIFIC NORTHWEST HAS A DECENT
MOISTURE FEED OR PLUME ASSOCIATED WITH IT. THE SATELLITE DERIVED
PERCENT OF NORMAL TOTAL PRECIPITABLE WATER PRODUCT SHOWED THAT
THERE WERE AMOUNTS OVER 200 PERCENT OF NORMAL ASSOCIATED WITH THE
UPCOMING SYSTEM.

THE HEAVIEST PRECIP IS EXPECTED TO FALL ON THE COAST AND IN THE
MOUNTAINS...WHERE TOTAL LIQUID PRECIP AMOUNTS ARE EXPECTED TO BE
IN THE 1 TO 2.5 INCH RANGE DURING THE 24 HOUR PERIOD ENDING AT 4
AM PST SATURDAY. THE CASCADES ABOVE THE 3500 FOOT LEVEL IS
EXPECTED TO RECEIVE 10 TO 16 INCHES OF NEW SNOW BY SATURDAY
MORNING.

STRONG WESTERLY WINDS WILL ALSO HELP TO ENHANCE SNOWFALL AMOUNTS
IN THE CASCADES...SO THERE WILL LIKELY BE LOCALIZED HIGHER
AMOUNTS. ALSO...A PUGET SOUND CONVERGENCE ZONE /PSCZ/ IS EXPECTED
TO DEVELOP LATE TONIGHT OR EARLY SATURDAY AND THIS WILL RESULT
IN LOCALLY HEAVY SNOW IN THE CASCADES NEAR THE KING/SNOHOMISH
COUNTY LINE. THE SNOW LEVELS WILL BRIEFLY RISE LATER TODAY OR
EARLY THIS EVENING BEFORE PLUMMETING TO NEAR 3000 FEET EARLY
SATURDAY. WILL NEED TO KEEP AN EYE ON EXACTLY WHERE THE PSCZ WILL
FORM BECAUSE THERE IS A DISTINCT POSSIBILITY THAT SNOQUALMIE PASS
COULD RECEIVE LOW END ADVISORY CRITERIA SNOWFALL AMOUNTS /6 OR 7
INCHES/ ON SATURDAY.

OTHER THAN THE SNOW IN THE MOUNTAINS...ANTICIPATE GUSTY WINDS
AHEAD OF AND WITH THE OCCLUDED FRONT THAT WILL SWEEP ACROSS LATE
TODAY THROUGH THIS EVENING. A WIND ADVISORY WAS ISSUED FOR THE
MORE WIND PRONE AREAS...NAMELY THE COAST AND PARTS OF THE
NORTHWEST INTERIOR.

THE UPPER TROF WILL MOVE ACROSS THE REGION SATURDAY MORNING BUT
EMBEDDED DISTURBANCES WITHIN THE STRONG WESTERLY FLOW WILL SERVE
TO KEEP WEATHER CONDITIONS UNSETTLED ACROSS THE CWA ON SATURDAY.
THE BEST CHANCE OF PRECIP WILL BE OVER THE MOUNTAINS...COAST...AND
WITHIN THE PSCZ.

THERE MAY BE A BRIEF BREAK IN THE ACTION SATURDAY EVENING BETWEEN
SYSTEMS BUT CANNOT COMPLETELY COUNT ON IT. THE NEXT SYSTEM WILL
QUICKLY FOLLOW ON THE HEELS OF THE DEPARTING ONE...WITH STEADY
PRECIP REDEVELOPING SATURDAY NIGHT. THIS NEXT SYSTEM WILL BE A
FAST ONE...THUS EXPECT THE COLD OR OCCLUDED FRONT TO SWEEP ACROSS
THE CWA LATE SUNDAY MORNING OR EARLY SUNDAY AFTERNOON. SHOWERY
CONDITIONS SHOULD PREVAIL SUNDAY AFTERNOON IN THE WAKE OF THE
FRONT. THE CASCADES ABOVE 3500 FEET CAN EXPECT TO RECEIVE ANOTHER
9 TO 15 INCHES OF NEW SNOW FROM THIS SYSTEM.

.LONG TERM...
CONFIDENCE IN THIS PERIOD WAS NOT HIGH DUE TO LACK OF AGREEMENT
BETWEEN THE MEDIUM RANGE SOLUTIONS AS WELL AS LACK OF RUN TO RUN
CONSISTENCY IN THE MODELS. EITHER THERE WILL BE AN UPPER TROF OVER
THE REGION ON WED OR AN UPPER RIDGE. DECIDED TO LEAVE THE INHERITED
FORECAST PRETTY MUCH INTACT.

&&

.HYDROLOGY...
RIVER FLOODING IS NOT EXPECTED THE NEXT 7 DAYS.

&&

.AVIATION...WESTERLY FLOW ALOFT AS A STRONG FRONTAL SYSTEM
APPROACHES THE COAST. THE AIR MASS IS MOIST AND STABLE EXCEPT FOR
ISOLATED SHOWERS NORTH PART. RAIN FROM THE APPROACHING FRONT WILL
SPREAD INLAND AROUND 15Z. THE FRONT WILL REACH THE COAST AROUND 00Z
AND PUGET SOUND AROUND 04Z. AT THE SURFACE STRONG GUSTY SOUTHEAST
WINDS WILL DEVELOP ALONG THE COAST AND OVER PARTS OF THE NORTH
INTERIOR THIS AFTERNOON AND CONTINUE INTO THE EVENING.

CEILINGS ARE GENERALLY VFR 4K-6K FT. CEILINGS WILL FALL TO MVFR
2K-3K FT IN RAIN 12Z-15Z AND STAY THERE ALL DAY. CEILINGS WILL NOT
IMPROVE MUCH TONIGHT IN ONSHORE SURFACE FLOW AND A SHOWERY PATTERN.

KSEA...DISCUSSION ABOVE APPLIES. WINDS SOUTHEAST 5-9 KT. RAIN AND
MVFR CONDITIONS WILL PREDOMINATE TODAY. WINDS WILL RISE TO SOUTHERLY
8-12 KT IN THE AFTERNOON. CHB

&&

.MARINE...A STRONG FRONTAL SYSTEM WILL MOVE THROUGH THE AREA TODAY.
GALE WARNINGS ARE UP FOR THE COASTAL WATERS AND THE EAST ENTRANCE
AND NORTH INLAND WATERS WITH SMALL CRAFT ADVISORIES ELSEWHERE.
FRONTAL PASSAGE ALONG THE COAST SHOULD BE AROUND 00Z...THEN AROUND
04Z OVER PUGET SOUND. A WESTERLY PUSH BEHIND THE FRONT WILL PRODUCE
SMALL CRAFT ADVISORY WEST WINDS THROUGH THE STRAIT...THOUGH A BRIEF
GALE IS ALSO POSSIBLE.

ANOTHER SYSTEM ON SUNDAY IS GAINING STRENGTH IN THE MODELS. THIS
COULD GIVE GALES ON THE COAST AND DOWN THE STRAIT. SWELLS IN THE
15-20 FOOT RANGE ARE FORECAST TO REACH THE COAST SUNDAY. CHB

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...WIND ADVISORIES ARE IN EFFECT FOR THE COAST AND PARTS OF THE
     NORTHWEST INTERIOR.

     WINTER WEATHER ADVISORY IN EFFECT FOR THE CASCADES ABOVE 3500
     FEET FROM 10 AM UNTIL 6 AM SATURDAY.

PZ...GALE WARNING IN EFFECT UNTIL 10 PM TONIGHT FOR THE COASTAL
     WATERS...EAST ENTRANCE TO THE STRAIT OF JUAN DE FUCA...AND
     THE NORTHERN INLAND WATERS.

     SMALL CRAFT ADVISORIES ARE IN EFFECT FOR THE REMAINING WATERS.

     SMALL CRAFT ADVISORY IN EFFECT FOR ROUGH BAR UNTIL 10 AM
     SATURDAY FOR THE GRAYS HARBOR BAR.

&&

$$

WWW.WEATHER.GOV/SEATTLE

YOU CAN SEE AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML





000
FXUS66 KOTX 211231
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
431 AM PST FRI NOV 21 2014

.SYNOPSIS...
A relatively quiet and cool overnight period with a few snow
showers over the north will give way to a sharp deterioration in
the weather on Friday as a strong and moist Pacific storm brings
valley rain and mountain snow Friday night followed by very windy
conditions on Saturday. An active and periodically wet weather
regime will continue through the next week.

&&

.DISCUSSION...
..BIGGEST SNOW MAKER SO FAR THIS  SEASON TO HIT MUCH OF THE INLAND
NORTHWEST LATER TODAY THROUGH SATURDAY...

Today and tonight ...Right now is the calm before the storm over
the Inland Northwest. All the region will see this morning is
some light precipitation in advance of a much wetter system
scheduled to move in later today. The 285k isentropic surface
continues to depict a fairly steep north-south pressure profile.
And this will become increasingly important this morning...as the
flow back toward more of a southerly orientation. This should make
light precipitation a little more widespread this
morning...especially over the northern third of Washington and the
northern half of the Idaho Panhandle. What makes this situation a
little more difficult than usual is the key dendritic layer will
be far from saturated. In fact only the layer from -10 to -15c
will have any moisture that nears saturation. This could lead to
periods of light freezing drizzle across the northern valleys in
addition to periodic snow. Amounts will be fairly light. By later
this morning though...the precipitation trends will begin to
increase steadily.

This precipitation increase will result from a good influx of
sub-tropical moisture. As of 2am...water vapor imagery was showing
a deep atmospheric river extending from west of Hawaii almost to
the Washington coast. This plume is expected to surge over the
Cascades by afternoon and remain over the region through much of
the night as a warm front invades the region. The front will
contribute to the warming temperatures over most valley locations.
The exception will be in the lee of the Cascades due to cold air
damming. The damming is expected to hold cold air over the
Waterville Plateau...Okanogan Valley...Wenatchee area...and
Cascade Valleys. Most of these locations still look like they will
see snow throughout the event. Models are fairly consistent on
dropping anywhere from .60-1.20 inches near the Cascades between
now and Saturday morning with values from .30-.80 inches across
most of the Inland Northwest. The combination of cold air and
heavy precipitation equates to a very good chance of heavy snow.
Valleys in the Cascades could see anywhere from 5-10 inches of
snow...with heavier amounts over the mountains...especially near
the crest. From Wenatchee to the Okanogan valleys...snow amount
should generally range from 3 to 6 inches...however that`s
assuming all the precipitation falls as snow. That notion is far
from a slam dunk for Wenatchee...the Wenatchee River Valley...and
Waterville Plateau...as there are signs that a fairly small
elevated melting layer will push into this area late this
afternoon or this evening. This would either put a strong damper
on the production of snow...or lead to a period of freezing rain.
The SREF would hedge toward the latter. This is far from a
confident notion as there are significant model differences. The
NAM would move this wedge over these areas almost at the onset of
the event...whereas the EC and GFS hold off until late this
evening. Not sure which model to believe...however the NAM may be
onto something as its handling surface temperatures much better
compared to surface observations. There is a much lesser chance of
this warm wedge moving as far north as Lake Chelan or the Okanogan
Valley. Elsewhere...the event looks primarily like a rain
maker...with snow levels gradually climbing to 3-4k feet over
northeast Washington and the north Idaho Panhandle...and anywhere
from 4-5k feet over the central Panhandle. There will likely be a
transition from snow to rain in the surrounding valleys...with 1
to 3 inches of snow a distinct possibility. Locally heavier
amounts are possible in valley locations close to the Canadian
border including Bonners Ferry...Metaline Falls and Laurier. The
widespread stratiform precipitation associated with the warm front
will transition to an unstable regime with the passage of a
significant shortwave trough and associated cold front. The front
should pass through the Cascades overnight and into the Idaho
Panhandle by early morning.

The front will finally provide the focus for mixing out all the
valleys with moderate to locally strong winds associated with good
downward momentum per cold air advection. Enough moisture and
instability will remain in place for numerous snow showers
primarily over the Idaho Panhandle and near the Cascades crest.
Meanwhile the lee valleys of the Cascades...Columbia Basin...and
the Spokane area will see a drying trend. It`s interesting to note
that with the passage of the cold front we will see a good
atmospheric destabilization and the NAM is actually showing some
small CAPE values over the central Panhandle by afternoon and
evening. This suggests we could see a significant development of
post frontal showers accompanied by locally heavy snow rates.
Elsewhere the main issue will be winds. Looks like the area could
see speeds approach wind advisory levels with sustained speeds of
20-25 mph with gusts of 40 mph possible. The strongest winds are
expected over the southeast Columbia Basin and Palouse. Based on
the myriad of highlights out at this time...we will defer this
issue to future shifts...but will give mention in hazardous
weather outlook. The strong winds will mix out any semblance of
modified arctic air...resulting in warming temps. However when
factoring in the winds...it certainly won`t feel warmer. fx

Saturday night through Tuesday night: A parade of systems will
in the northwest flow will bring precipitation every other day or
so. This comes with the potential for an extended period of wet
weather starting Monday night or Tuesday, accompanied by milder
and perhaps slightly above seasonal normal temperatures. However
model agreement falters by this time frame and forecast confidence
is degraded.

Saturday night one system pulls east. This and the northwest flow
will keep the threat of snow alive across the Panhandle and
southeast WA through evening. Chances will wane overnight as the
system exits. At the same time the lingering threat of snow near
the Cascade crest in the onshore flow will be bolstered by the
moisture and lift increasing with the next warm front overnight.
Meanwhile the remainder of central and eastern WA will continue to
be plagued by low clouds, as well as a threat of patchy fog.

Sunday the warm front moves into eastern WA and north ID,
bringing the next round of snow and rain. Models have sped up the
start of precipitation for the morning, at least slightly. By
afternoon the trailing occluded front comes into central WA,
lessening the precipitation in the lee of the Cascades and western
Basin. Yet east of here the threat will remain high through
evening, due to the passing occluded front, a lingering theta-e
ridge that weakens near the ID/WA border and the northwest flow.
Within this region models place the higher precipitation amounts
over southeast WA through the central Panhandle. The threat
appears to gradually wane overnight as the feature weakens.

As for precipitation-type and amounts: in the morning snow will
be the predominate threat. Exceptions will be over the deeper
Columbia Basin and L-C Valley where rain will be more likely. By
afternoon the main snow threat backs into the Cascades and lifts
toward the northern WA and ID Panhandle mountains, while mainly
rain or a rain/snow mix will be more likely over the Columbia
Basin eastward to the lower elevations of the Panhandle. As
compared to Friday`s system, the lift is weaker and the moisture
tap is not as impressive. So precipitation amounts look lower. Yet
with that said they are still modest in some areas. While models
generally depict less than a tenth toward the lee of the Cascades
and western Basin, they show between a tenth and a quarter of inch
over the eastern Basin. Near half an inch is depicted in the
eastern mountains and near an inch near the Cascade crest. Falling
as snow this could result in more moderate to locally heavy snow
amounts around the mountains. Yet even the lower elevations could
see some accumulations; early total suggest maybe a half inch to
an inch, with local amounts near two in some of the northern
mountain valleys.

Between Monday and Tuesday the next weather maker arrives. There
are still some questions about the evolution of the system,
including precipitation amounts and type. Yet it has the potential
to be a wet and milder period. By Monday afternoon and evening the
next warm front lifts across the region. The associated surface
low tracks from the central BC coast Monday morning to northeast
MT Tuesday morning. However models do not indicate a strong push
from the north behind that low. This is due to yet another system
moving across the Gulf of Alaska into western BC by Tuesday, which
should stalling things. This latter feature keeps a quasi-
stationary front across northeast WA through the central Panhandle
Monday night into Tuesday. Furthermore models show at least two
smaller-scale low pressure centers moves along that stalled front,
a relatively weak one Tuesday morning and a stronger low pressure
center late Tuesday into Tuesday night. Furthermore models show
another good subtropical moisture tap. PWATs rise to between 0.50
and 0.85 inches by Tuesday (or between 130 to 225% of normal).

So this evolution suggests another round of precipitation. Its
precise evolution may easily change. Yet right now models suggest
precipitation developing first around the Cascades and northern
mountains Monday (albeit light), before expanding across the
eastern third of WA and the ID Panhandle Monday night into Tuesday
morning. Chances remain high into Tuesday night with precipitation
rates on the rise, especially if models continue to depict that
stronger low moving along the stalled front. There are caveats to
this high precipitation threat. In the continued west-northwest
flow models paint the highest precipitation amounts across the
Cascade crest and across the Idaho Panhandle, save for the places
like the L-C Valley. Yet in the lee of the Cascades and western
Basin the west-northwest flow may provide enough to keep things
drier, due to the downsloping/shadow effect, at least for at least
a portion of this period. The best threat of precipitation in the
region may come around Tuesday afternoon into Tuesday evening,
when that second strong low moves along that stall boundary. In
addition if the stalled boundary remains further north, then the
precipitation threat may be diminished away from the all but the
Cascades and northern mountains.

As for precipitation-type during this time frame: snow levels
look to be on the rise. Initially models keep colder air in place.
Snow levels are currently projected to be around 1500 to 3500
feet, lowest toward NE WA and north ID. However all models show
the jet stream lifting north and miler air surging in. Monday
night into Tuesday morning models show snow level rise to between
5000 and 8000 feet across the Cascades through southeast WA,
though they linger near 2500 to 4000 feet across northeast WA and
the ID Panhandle. Going into Tuesday afternoon and night models
push snow levels up to between 7000 to 8000 feet over much of the
region, with the main sticky point at this time toward the
Canadian border where some still keep them at low as 3000 feet. So
these will continue to be fine-tuned, I`m sure. Overall this means
the potential for snow early Monday, changes to primarily rain
Monday night into Tuesday, save for the potential for snow to
linger longer at lower elevations northern counties where
confidence is lower. /J. Cote`

Wednesday through Friday: While many are planning for a busy
Thanksgiving travel period, the forecast continues to hinder the
planning process as it remains up in the air at this point with
lots of uncertainty. Just as models started to come into some sort
of agreement earlier today, the latest ECMWF jumped off the deep
end depicting what the GFS was showing several runs ago. While the
latest Euro now shows a fair amount of ridging on the west coast
leading to warmer and drier conditions, the GFS continues to
bring cooler northwesterly flow onshore keeping temps a bit cooler
and the pattern a bit more active. Due to the large amount of
inconsistencies in model comparison and run to run evaluation,
very few changes were made to the forecast as it could have hurt
more than helped at this point. The main change was to raise
temperatures and in turn snow levels as well to values above most
valley floors throughout the extended leading to any precipitation
to fall as valley rain and mountain snow. Both the GFS and ECMWF
had wet bulb zero temps depicted much further north than
previously shown so the mentioned changes were made. POPs were
left essentially untouched and we will hope for considerable
improvements in model consistency in the near future to get a
better sense of what we can expect for the holiday period.
/Fliehman

&&

.AVIATION...
12Z TAFS: MVFR Ceilings and vis continues to be common over the
region this morning as a moist boundary layer and light winds
exists under a strong low level inversion...with a mix of MVFR to
LIFR conditions at the northern and western TAF sites. Downsloping
winds at KPUW and KLWS will keep them in the VFR category. A very
moist Pacific storm system will spread thickening clouds over the
region on Friday with -SN/-RA to develop aft 19z in KEAT and aft
23z at KGEG eastward. Pcpn will vary btwn -SN, -RA and -FZRA at
KEAT and could be moderate at times. Warmer conditions will bring
rain to KMWH/KGEG/KSFF/KCOE/KPUW/KLWS. Ceilings with the
precipitation are once again expected to drop to MVFR or even IFR
conditions. /Fliehman





&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        37  36  42  30  38  29 /  30 100  20  20  70  30
Coeur d`Alene  38  36  42  31  39  30 /  40 100  50  20  70  40
Pullman        42  37  44  33  41  31 /  10 100  70  50  70  60
Lewiston       46  41  48  36  46  34 /  10 100  60  30  60  40
Colville       36  34  42  23  37  23 /  90 100  20  10  60  20
Sandpoint      34  34  40  29  37  30 /  80 100  70  30  70  40
Kellogg        36  35  39  31  35  31 /  60 100  80  60  80  60
Moses Lake     36  33  47  28  44  29 /  90 100  10  10  30  10
Wenatchee      34  34  45  33  43  31 / 100 100  10  10  40  20
Omak           34  32  42  26  37  27 / 100 100  10  10  30  20

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Air Stagnation Advisory until Noon PST today for Central
     Panhandle Mountains-Coeur d`Alene Area-Idaho Palouse-
     Northern Panhandle.

     Winter Storm Warning from Noon today to 6 PM PST Saturday for
     Northern Panhandle.

     Winter Storm Warning from Noon today to 6 AM PST Sunday for
     Central Panhandle Mountains.

WA...Air Stagnation Advisory until Noon PST today for East Slopes
     Northern Cascades-Lower Garfield and Asotin Counties-Moses
     Lake Area-Northeast Mountains-Okanogan Highlands-Spokane
     Area-Upper Columbia Basin-Washington Palouse-Waterville
     Plateau-Wenatchee Area.

     Winter Storm Warning from Noon today to 6 AM PST Saturday for
     East Slopes Northern Cascades-Okanogan Highlands-Okanogan
     Valley-Waterville Plateau.

     Winter Storm Warning from Noon today to 6 PM PST Saturday for
     Northeast Mountains.

     Winter Weather Advisory from Noon today to 6 AM PST Saturday for
     Wenatchee Area.

&&

$$





000
FXUS66 KOTX 211231
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
431 AM PST FRI NOV 21 2014

.SYNOPSIS...
A relatively quiet and cool overnight period with a few snow
showers over the north will give way to a sharp deterioration in
the weather on Friday as a strong and moist Pacific storm brings
valley rain and mountain snow Friday night followed by very windy
conditions on Saturday. An active and periodically wet weather
regime will continue through the next week.

&&

.DISCUSSION...
..BIGGEST SNOW MAKER SO FAR THIS  SEASON TO HIT MUCH OF THE INLAND
NORTHWEST LATER TODAY THROUGH SATURDAY...

Today and tonight ...Right now is the calm before the storm over
the Inland Northwest. All the region will see this morning is
some light precipitation in advance of a much wetter system
scheduled to move in later today. The 285k isentropic surface
continues to depict a fairly steep north-south pressure profile.
And this will become increasingly important this morning...as the
flow back toward more of a southerly orientation. This should make
light precipitation a little more widespread this
morning...especially over the northern third of Washington and the
northern half of the Idaho Panhandle. What makes this situation a
little more difficult than usual is the key dendritic layer will
be far from saturated. In fact only the layer from -10 to -15c
will have any moisture that nears saturation. This could lead to
periods of light freezing drizzle across the northern valleys in
addition to periodic snow. Amounts will be fairly light. By later
this morning though...the precipitation trends will begin to
increase steadily.

This precipitation increase will result from a good influx of
sub-tropical moisture. As of 2am...water vapor imagery was showing
a deep atmospheric river extending from west of Hawaii almost to
the Washington coast. This plume is expected to surge over the
Cascades by afternoon and remain over the region through much of
the night as a warm front invades the region. The front will
contribute to the warming temperatures over most valley locations.
The exception will be in the lee of the Cascades due to cold air
damming. The damming is expected to hold cold air over the
Waterville Plateau...Okanogan Valley...Wenatchee area...and
Cascade Valleys. Most of these locations still look like they will
see snow throughout the event. Models are fairly consistent on
dropping anywhere from .60-1.20 inches near the Cascades between
now and Saturday morning with values from .30-.80 inches across
most of the Inland Northwest. The combination of cold air and
heavy precipitation equates to a very good chance of heavy snow.
Valleys in the Cascades could see anywhere from 5-10 inches of
snow...with heavier amounts over the mountains...especially near
the crest. From Wenatchee to the Okanogan valleys...snow amount
should generally range from 3 to 6 inches...however that`s
assuming all the precipitation falls as snow. That notion is far
from a slam dunk for Wenatchee...the Wenatchee River Valley...and
Waterville Plateau...as there are signs that a fairly small
elevated melting layer will push into this area late this
afternoon or this evening. This would either put a strong damper
on the production of snow...or lead to a period of freezing rain.
The SREF would hedge toward the latter. This is far from a
confident notion as there are significant model differences. The
NAM would move this wedge over these areas almost at the onset of
the event...whereas the EC and GFS hold off until late this
evening. Not sure which model to believe...however the NAM may be
onto something as its handling surface temperatures much better
compared to surface observations. There is a much lesser chance of
this warm wedge moving as far north as Lake Chelan or the Okanogan
Valley. Elsewhere...the event looks primarily like a rain
maker...with snow levels gradually climbing to 3-4k feet over
northeast Washington and the north Idaho Panhandle...and anywhere
from 4-5k feet over the central Panhandle. There will likely be a
transition from snow to rain in the surrounding valleys...with 1
to 3 inches of snow a distinct possibility. Locally heavier
amounts are possible in valley locations close to the Canadian
border including Bonners Ferry...Metaline Falls and Laurier. The
widespread stratiform precipitation associated with the warm front
will transition to an unstable regime with the passage of a
significant shortwave trough and associated cold front. The front
should pass through the Cascades overnight and into the Idaho
Panhandle by early morning.

The front will finally provide the focus for mixing out all the
valleys with moderate to locally strong winds associated with good
downward momentum per cold air advection. Enough moisture and
instability will remain in place for numerous snow showers
primarily over the Idaho Panhandle and near the Cascades crest.
Meanwhile the lee valleys of the Cascades...Columbia Basin...and
the Spokane area will see a drying trend. It`s interesting to note
that with the passage of the cold front we will see a good
atmospheric destabilization and the NAM is actually showing some
small CAPE values over the central Panhandle by afternoon and
evening. This suggests we could see a significant development of
post frontal showers accompanied by locally heavy snow rates.
Elsewhere the main issue will be winds. Looks like the area could
see speeds approach wind advisory levels with sustained speeds of
20-25 mph with gusts of 40 mph possible. The strongest winds are
expected over the southeast Columbia Basin and Palouse. Based on
the myriad of highlights out at this time...we will defer this
issue to future shifts...but will give mention in hazardous
weather outlook. The strong winds will mix out any semblance of
modified arctic air...resulting in warming temps. However when
factoring in the winds...it certainly won`t feel warmer. fx

Saturday night through Tuesday night: A parade of systems will
in the northwest flow will bring precipitation every other day or
so. This comes with the potential for an extended period of wet
weather starting Monday night or Tuesday, accompanied by milder
and perhaps slightly above seasonal normal temperatures. However
model agreement falters by this time frame and forecast confidence
is degraded.

Saturday night one system pulls east. This and the northwest flow
will keep the threat of snow alive across the Panhandle and
southeast WA through evening. Chances will wane overnight as the
system exits. At the same time the lingering threat of snow near
the Cascade crest in the onshore flow will be bolstered by the
moisture and lift increasing with the next warm front overnight.
Meanwhile the remainder of central and eastern WA will continue to
be plagued by low clouds, as well as a threat of patchy fog.

Sunday the warm front moves into eastern WA and north ID,
bringing the next round of snow and rain. Models have sped up the
start of precipitation for the morning, at least slightly. By
afternoon the trailing occluded front comes into central WA,
lessening the precipitation in the lee of the Cascades and western
Basin. Yet east of here the threat will remain high through
evening, due to the passing occluded front, a lingering theta-e
ridge that weakens near the ID/WA border and the northwest flow.
Within this region models place the higher precipitation amounts
over southeast WA through the central Panhandle. The threat
appears to gradually wane overnight as the feature weakens.

As for precipitation-type and amounts: in the morning snow will
be the predominate threat. Exceptions will be over the deeper
Columbia Basin and L-C Valley where rain will be more likely. By
afternoon the main snow threat backs into the Cascades and lifts
toward the northern WA and ID Panhandle mountains, while mainly
rain or a rain/snow mix will be more likely over the Columbia
Basin eastward to the lower elevations of the Panhandle. As
compared to Friday`s system, the lift is weaker and the moisture
tap is not as impressive. So precipitation amounts look lower. Yet
with that said they are still modest in some areas. While models
generally depict less than a tenth toward the lee of the Cascades
and western Basin, they show between a tenth and a quarter of inch
over the eastern Basin. Near half an inch is depicted in the
eastern mountains and near an inch near the Cascade crest. Falling
as snow this could result in more moderate to locally heavy snow
amounts around the mountains. Yet even the lower elevations could
see some accumulations; early total suggest maybe a half inch to
an inch, with local amounts near two in some of the northern
mountain valleys.

Between Monday and Tuesday the next weather maker arrives. There
are still some questions about the evolution of the system,
including precipitation amounts and type. Yet it has the potential
to be a wet and milder period. By Monday afternoon and evening the
next warm front lifts across the region. The associated surface
low tracks from the central BC coast Monday morning to northeast
MT Tuesday morning. However models do not indicate a strong push
from the north behind that low. This is due to yet another system
moving across the Gulf of Alaska into western BC by Tuesday, which
should stalling things. This latter feature keeps a quasi-
stationary front across northeast WA through the central Panhandle
Monday night into Tuesday. Furthermore models show at least two
smaller-scale low pressure centers moves along that stalled front,
a relatively weak one Tuesday morning and a stronger low pressure
center late Tuesday into Tuesday night. Furthermore models show
another good subtropical moisture tap. PWATs rise to between 0.50
and 0.85 inches by Tuesday (or between 130 to 225% of normal).

So this evolution suggests another round of precipitation. Its
precise evolution may easily change. Yet right now models suggest
precipitation developing first around the Cascades and northern
mountains Monday (albeit light), before expanding across the
eastern third of WA and the ID Panhandle Monday night into Tuesday
morning. Chances remain high into Tuesday night with precipitation
rates on the rise, especially if models continue to depict that
stronger low moving along the stalled front. There are caveats to
this high precipitation threat. In the continued west-northwest
flow models paint the highest precipitation amounts across the
Cascade crest and across the Idaho Panhandle, save for the places
like the L-C Valley. Yet in the lee of the Cascades and western
Basin the west-northwest flow may provide enough to keep things
drier, due to the downsloping/shadow effect, at least for at least
a portion of this period. The best threat of precipitation in the
region may come around Tuesday afternoon into Tuesday evening,
when that second strong low moves along that stall boundary. In
addition if the stalled boundary remains further north, then the
precipitation threat may be diminished away from the all but the
Cascades and northern mountains.

As for precipitation-type during this time frame: snow levels
look to be on the rise. Initially models keep colder air in place.
Snow levels are currently projected to be around 1500 to 3500
feet, lowest toward NE WA and north ID. However all models show
the jet stream lifting north and miler air surging in. Monday
night into Tuesday morning models show snow level rise to between
5000 and 8000 feet across the Cascades through southeast WA,
though they linger near 2500 to 4000 feet across northeast WA and
the ID Panhandle. Going into Tuesday afternoon and night models
push snow levels up to between 7000 to 8000 feet over much of the
region, with the main sticky point at this time toward the
Canadian border where some still keep them at low as 3000 feet. So
these will continue to be fine-tuned, I`m sure. Overall this means
the potential for snow early Monday, changes to primarily rain
Monday night into Tuesday, save for the potential for snow to
linger longer at lower elevations northern counties where
confidence is lower. /J. Cote`

Wednesday through Friday: While many are planning for a busy
Thanksgiving travel period, the forecast continues to hinder the
planning process as it remains up in the air at this point with
lots of uncertainty. Just as models started to come into some sort
of agreement earlier today, the latest ECMWF jumped off the deep
end depicting what the GFS was showing several runs ago. While the
latest Euro now shows a fair amount of ridging on the west coast
leading to warmer and drier conditions, the GFS continues to
bring cooler northwesterly flow onshore keeping temps a bit cooler
and the pattern a bit more active. Due to the large amount of
inconsistencies in model comparison and run to run evaluation,
very few changes were made to the forecast as it could have hurt
more than helped at this point. The main change was to raise
temperatures and in turn snow levels as well to values above most
valley floors throughout the extended leading to any precipitation
to fall as valley rain and mountain snow. Both the GFS and ECMWF
had wet bulb zero temps depicted much further north than
previously shown so the mentioned changes were made. POPs were
left essentially untouched and we will hope for considerable
improvements in model consistency in the near future to get a
better sense of what we can expect for the holiday period.
/Fliehman

&&

.AVIATION...
12Z TAFS: MVFR Ceilings and vis continues to be common over the
region this morning as a moist boundary layer and light winds
exists under a strong low level inversion...with a mix of MVFR to
LIFR conditions at the northern and western TAF sites. Downsloping
winds at KPUW and KLWS will keep them in the VFR category. A very
moist Pacific storm system will spread thickening clouds over the
region on Friday with -SN/-RA to develop aft 19z in KEAT and aft
23z at KGEG eastward. Pcpn will vary btwn -SN, -RA and -FZRA at
KEAT and could be moderate at times. Warmer conditions will bring
rain to KMWH/KGEG/KSFF/KCOE/KPUW/KLWS. Ceilings with the
precipitation are once again expected to drop to MVFR or even IFR
conditions. /Fliehman





&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        37  36  42  30  38  29 /  30 100  20  20  70  30
Coeur d`Alene  38  36  42  31  39  30 /  40 100  50  20  70  40
Pullman        42  37  44  33  41  31 /  10 100  70  50  70  60
Lewiston       46  41  48  36  46  34 /  10 100  60  30  60  40
Colville       36  34  42  23  37  23 /  90 100  20  10  60  20
Sandpoint      34  34  40  29  37  30 /  80 100  70  30  70  40
Kellogg        36  35  39  31  35  31 /  60 100  80  60  80  60
Moses Lake     36  33  47  28  44  29 /  90 100  10  10  30  10
Wenatchee      34  34  45  33  43  31 / 100 100  10  10  40  20
Omak           34  32  42  26  37  27 / 100 100  10  10  30  20

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Air Stagnation Advisory until Noon PST today for Central
     Panhandle Mountains-Coeur d`Alene Area-Idaho Palouse-
     Northern Panhandle.

     Winter Storm Warning from Noon today to 6 PM PST Saturday for
     Northern Panhandle.

     Winter Storm Warning from Noon today to 6 AM PST Sunday for
     Central Panhandle Mountains.

WA...Air Stagnation Advisory until Noon PST today for East Slopes
     Northern Cascades-Lower Garfield and Asotin Counties-Moses
     Lake Area-Northeast Mountains-Okanogan Highlands-Spokane
     Area-Upper Columbia Basin-Washington Palouse-Waterville
     Plateau-Wenatchee Area.

     Winter Storm Warning from Noon today to 6 AM PST Saturday for
     East Slopes Northern Cascades-Okanogan Highlands-Okanogan
     Valley-Waterville Plateau.

     Winter Storm Warning from Noon today to 6 PM PST Saturday for
     Northeast Mountains.

     Winter Weather Advisory from Noon today to 6 AM PST Saturday for
     Wenatchee Area.

&&

$$





000
FXUS66 KOTX 211231
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
431 AM PST FRI NOV 21 2014

.SYNOPSIS...
A relatively quiet and cool overnight period with a few snow
showers over the north will give way to a sharp deterioration in
the weather on Friday as a strong and moist Pacific storm brings
valley rain and mountain snow Friday night followed by very windy
conditions on Saturday. An active and periodically wet weather
regime will continue through the next week.

&&

.DISCUSSION...
..BIGGEST SNOW MAKER SO FAR THIS  SEASON TO HIT MUCH OF THE INLAND
NORTHWEST LATER TODAY THROUGH SATURDAY...

Today and tonight ...Right now is the calm before the storm over
the Inland Northwest. All the region will see this morning is
some light precipitation in advance of a much wetter system
scheduled to move in later today. The 285k isentropic surface
continues to depict a fairly steep north-south pressure profile.
And this will become increasingly important this morning...as the
flow back toward more of a southerly orientation. This should make
light precipitation a little more widespread this
morning...especially over the northern third of Washington and the
northern half of the Idaho Panhandle. What makes this situation a
little more difficult than usual is the key dendritic layer will
be far from saturated. In fact only the layer from -10 to -15c
will have any moisture that nears saturation. This could lead to
periods of light freezing drizzle across the northern valleys in
addition to periodic snow. Amounts will be fairly light. By later
this morning though...the precipitation trends will begin to
increase steadily.

This precipitation increase will result from a good influx of
sub-tropical moisture. As of 2am...water vapor imagery was showing
a deep atmospheric river extending from west of Hawaii almost to
the Washington coast. This plume is expected to surge over the
Cascades by afternoon and remain over the region through much of
the night as a warm front invades the region. The front will
contribute to the warming temperatures over most valley locations.
The exception will be in the lee of the Cascades due to cold air
damming. The damming is expected to hold cold air over the
Waterville Plateau...Okanogan Valley...Wenatchee area...and
Cascade Valleys. Most of these locations still look like they will
see snow throughout the event. Models are fairly consistent on
dropping anywhere from .60-1.20 inches near the Cascades between
now and Saturday morning with values from .30-.80 inches across
most of the Inland Northwest. The combination of cold air and
heavy precipitation equates to a very good chance of heavy snow.
Valleys in the Cascades could see anywhere from 5-10 inches of
snow...with heavier amounts over the mountains...especially near
the crest. From Wenatchee to the Okanogan valleys...snow amount
should generally range from 3 to 6 inches...however that`s
assuming all the precipitation falls as snow. That notion is far
from a slam dunk for Wenatchee...the Wenatchee River Valley...and
Waterville Plateau...as there are signs that a fairly small
elevated melting layer will push into this area late this
afternoon or this evening. This would either put a strong damper
on the production of snow...or lead to a period of freezing rain.
The SREF would hedge toward the latter. This is far from a
confident notion as there are significant model differences. The
NAM would move this wedge over these areas almost at the onset of
the event...whereas the EC and GFS hold off until late this
evening. Not sure which model to believe...however the NAM may be
onto something as its handling surface temperatures much better
compared to surface observations. There is a much lesser chance of
this warm wedge moving as far north as Lake Chelan or the Okanogan
Valley. Elsewhere...the event looks primarily like a rain
maker...with snow levels gradually climbing to 3-4k feet over
northeast Washington and the north Idaho Panhandle...and anywhere
from 4-5k feet over the central Panhandle. There will likely be a
transition from snow to rain in the surrounding valleys...with 1
to 3 inches of snow a distinct possibility. Locally heavier
amounts are possible in valley locations close to the Canadian
border including Bonners Ferry...Metaline Falls and Laurier. The
widespread stratiform precipitation associated with the warm front
will transition to an unstable regime with the passage of a
significant shortwave trough and associated cold front. The front
should pass through the Cascades overnight and into the Idaho
Panhandle by early morning.

The front will finally provide the focus for mixing out all the
valleys with moderate to locally strong winds associated with good
downward momentum per cold air advection. Enough moisture and
instability will remain in place for numerous snow showers
primarily over the Idaho Panhandle and near the Cascades crest.
Meanwhile the lee valleys of the Cascades...Columbia Basin...and
the Spokane area will see a drying trend. It`s interesting to note
that with the passage of the cold front we will see a good
atmospheric destabilization and the NAM is actually showing some
small CAPE values over the central Panhandle by afternoon and
evening. This suggests we could see a significant development of
post frontal showers accompanied by locally heavy snow rates.
Elsewhere the main issue will be winds. Looks like the area could
see speeds approach wind advisory levels with sustained speeds of
20-25 mph with gusts of 40 mph possible. The strongest winds are
expected over the southeast Columbia Basin and Palouse. Based on
the myriad of highlights out at this time...we will defer this
issue to future shifts...but will give mention in hazardous
weather outlook. The strong winds will mix out any semblance of
modified arctic air...resulting in warming temps. However when
factoring in the winds...it certainly won`t feel warmer. fx

Saturday night through Tuesday night: A parade of systems will
in the northwest flow will bring precipitation every other day or
so. This comes with the potential for an extended period of wet
weather starting Monday night or Tuesday, accompanied by milder
and perhaps slightly above seasonal normal temperatures. However
model agreement falters by this time frame and forecast confidence
is degraded.

Saturday night one system pulls east. This and the northwest flow
will keep the threat of snow alive across the Panhandle and
southeast WA through evening. Chances will wane overnight as the
system exits. At the same time the lingering threat of snow near
the Cascade crest in the onshore flow will be bolstered by the
moisture and lift increasing with the next warm front overnight.
Meanwhile the remainder of central and eastern WA will continue to
be plagued by low clouds, as well as a threat of patchy fog.

Sunday the warm front moves into eastern WA and north ID,
bringing the next round of snow and rain. Models have sped up the
start of precipitation for the morning, at least slightly. By
afternoon the trailing occluded front comes into central WA,
lessening the precipitation in the lee of the Cascades and western
Basin. Yet east of here the threat will remain high through
evening, due to the passing occluded front, a lingering theta-e
ridge that weakens near the ID/WA border and the northwest flow.
Within this region models place the higher precipitation amounts
over southeast WA through the central Panhandle. The threat
appears to gradually wane overnight as the feature weakens.

As for precipitation-type and amounts: in the morning snow will
be the predominate threat. Exceptions will be over the deeper
Columbia Basin and L-C Valley where rain will be more likely. By
afternoon the main snow threat backs into the Cascades and lifts
toward the northern WA and ID Panhandle mountains, while mainly
rain or a rain/snow mix will be more likely over the Columbia
Basin eastward to the lower elevations of the Panhandle. As
compared to Friday`s system, the lift is weaker and the moisture
tap is not as impressive. So precipitation amounts look lower. Yet
with that said they are still modest in some areas. While models
generally depict less than a tenth toward the lee of the Cascades
and western Basin, they show between a tenth and a quarter of inch
over the eastern Basin. Near half an inch is depicted in the
eastern mountains and near an inch near the Cascade crest. Falling
as snow this could result in more moderate to locally heavy snow
amounts around the mountains. Yet even the lower elevations could
see some accumulations; early total suggest maybe a half inch to
an inch, with local amounts near two in some of the northern
mountain valleys.

Between Monday and Tuesday the next weather maker arrives. There
are still some questions about the evolution of the system,
including precipitation amounts and type. Yet it has the potential
to be a wet and milder period. By Monday afternoon and evening the
next warm front lifts across the region. The associated surface
low tracks from the central BC coast Monday morning to northeast
MT Tuesday morning. However models do not indicate a strong push
from the north behind that low. This is due to yet another system
moving across the Gulf of Alaska into western BC by Tuesday, which
should stalling things. This latter feature keeps a quasi-
stationary front across northeast WA through the central Panhandle
Monday night into Tuesday. Furthermore models show at least two
smaller-scale low pressure centers moves along that stalled front,
a relatively weak one Tuesday morning and a stronger low pressure
center late Tuesday into Tuesday night. Furthermore models show
another good subtropical moisture tap. PWATs rise to between 0.50
and 0.85 inches by Tuesday (or between 130 to 225% of normal).

So this evolution suggests another round of precipitation. Its
precise evolution may easily change. Yet right now models suggest
precipitation developing first around the Cascades and northern
mountains Monday (albeit light), before expanding across the
eastern third of WA and the ID Panhandle Monday night into Tuesday
morning. Chances remain high into Tuesday night with precipitation
rates on the rise, especially if models continue to depict that
stronger low moving along the stalled front. There are caveats to
this high precipitation threat. In the continued west-northwest
flow models paint the highest precipitation amounts across the
Cascade crest and across the Idaho Panhandle, save for the places
like the L-C Valley. Yet in the lee of the Cascades and western
Basin the west-northwest flow may provide enough to keep things
drier, due to the downsloping/shadow effect, at least for at least
a portion of this period. The best threat of precipitation in the
region may come around Tuesday afternoon into Tuesday evening,
when that second strong low moves along that stall boundary. In
addition if the stalled boundary remains further north, then the
precipitation threat may be diminished away from the all but the
Cascades and northern mountains.

As for precipitation-type during this time frame: snow levels
look to be on the rise. Initially models keep colder air in place.
Snow levels are currently projected to be around 1500 to 3500
feet, lowest toward NE WA and north ID. However all models show
the jet stream lifting north and miler air surging in. Monday
night into Tuesday morning models show snow level rise to between
5000 and 8000 feet across the Cascades through southeast WA,
though they linger near 2500 to 4000 feet across northeast WA and
the ID Panhandle. Going into Tuesday afternoon and night models
push snow levels up to between 7000 to 8000 feet over much of the
region, with the main sticky point at this time toward the
Canadian border where some still keep them at low as 3000 feet. So
these will continue to be fine-tuned, I`m sure. Overall this means
the potential for snow early Monday, changes to primarily rain
Monday night into Tuesday, save for the potential for snow to
linger longer at lower elevations northern counties where
confidence is lower. /J. Cote`

Wednesday through Friday: While many are planning for a busy
Thanksgiving travel period, the forecast continues to hinder the
planning process as it remains up in the air at this point with
lots of uncertainty. Just as models started to come into some sort
of agreement earlier today, the latest ECMWF jumped off the deep
end depicting what the GFS was showing several runs ago. While the
latest Euro now shows a fair amount of ridging on the west coast
leading to warmer and drier conditions, the GFS continues to
bring cooler northwesterly flow onshore keeping temps a bit cooler
and the pattern a bit more active. Due to the large amount of
inconsistencies in model comparison and run to run evaluation,
very few changes were made to the forecast as it could have hurt
more than helped at this point. The main change was to raise
temperatures and in turn snow levels as well to values above most
valley floors throughout the extended leading to any precipitation
to fall as valley rain and mountain snow. Both the GFS and ECMWF
had wet bulb zero temps depicted much further north than
previously shown so the mentioned changes were made. POPs were
left essentially untouched and we will hope for considerable
improvements in model consistency in the near future to get a
better sense of what we can expect for the holiday period.
/Fliehman

&&

.AVIATION...
12Z TAFS: MVFR Ceilings and vis continues to be common over the
region this morning as a moist boundary layer and light winds
exists under a strong low level inversion...with a mix of MVFR to
LIFR conditions at the northern and western TAF sites. Downsloping
winds at KPUW and KLWS will keep them in the VFR category. A very
moist Pacific storm system will spread thickening clouds over the
region on Friday with -SN/-RA to develop aft 19z in KEAT and aft
23z at KGEG eastward. Pcpn will vary btwn -SN, -RA and -FZRA at
KEAT and could be moderate at times. Warmer conditions will bring
rain to KMWH/KGEG/KSFF/KCOE/KPUW/KLWS. Ceilings with the
precipitation are once again expected to drop to MVFR or even IFR
conditions. /Fliehman





&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        37  36  42  30  38  29 /  30 100  20  20  70  30
Coeur d`Alene  38  36  42  31  39  30 /  40 100  50  20  70  40
Pullman        42  37  44  33  41  31 /  10 100  70  50  70  60
Lewiston       46  41  48  36  46  34 /  10 100  60  30  60  40
Colville       36  34  42  23  37  23 /  90 100  20  10  60  20
Sandpoint      34  34  40  29  37  30 /  80 100  70  30  70  40
Kellogg        36  35  39  31  35  31 /  60 100  80  60  80  60
Moses Lake     36  33  47  28  44  29 /  90 100  10  10  30  10
Wenatchee      34  34  45  33  43  31 / 100 100  10  10  40  20
Omak           34  32  42  26  37  27 / 100 100  10  10  30  20

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Air Stagnation Advisory until Noon PST today for Central
     Panhandle Mountains-Coeur d`Alene Area-Idaho Palouse-
     Northern Panhandle.

     Winter Storm Warning from Noon today to 6 PM PST Saturday for
     Northern Panhandle.

     Winter Storm Warning from Noon today to 6 AM PST Sunday for
     Central Panhandle Mountains.

WA...Air Stagnation Advisory until Noon PST today for East Slopes
     Northern Cascades-Lower Garfield and Asotin Counties-Moses
     Lake Area-Northeast Mountains-Okanogan Highlands-Spokane
     Area-Upper Columbia Basin-Washington Palouse-Waterville
     Plateau-Wenatchee Area.

     Winter Storm Warning from Noon today to 6 AM PST Saturday for
     East Slopes Northern Cascades-Okanogan Highlands-Okanogan
     Valley-Waterville Plateau.

     Winter Storm Warning from Noon today to 6 PM PST Saturday for
     Northeast Mountains.

     Winter Weather Advisory from Noon today to 6 AM PST Saturday for
     Wenatchee Area.

&&

$$





000
FXUS66 KOTX 211231
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
431 AM PST FRI NOV 21 2014

.SYNOPSIS...
A relatively quiet and cool overnight period with a few snow
showers over the north will give way to a sharp deterioration in
the weather on Friday as a strong and moist Pacific storm brings
valley rain and mountain snow Friday night followed by very windy
conditions on Saturday. An active and periodically wet weather
regime will continue through the next week.

&&

.DISCUSSION...
..BIGGEST SNOW MAKER SO FAR THIS  SEASON TO HIT MUCH OF THE INLAND
NORTHWEST LATER TODAY THROUGH SATURDAY...

Today and tonight ...Right now is the calm before the storm over
the Inland Northwest. All the region will see this morning is
some light precipitation in advance of a much wetter system
scheduled to move in later today. The 285k isentropic surface
continues to depict a fairly steep north-south pressure profile.
And this will become increasingly important this morning...as the
flow back toward more of a southerly orientation. This should make
light precipitation a little more widespread this
morning...especially over the northern third of Washington and the
northern half of the Idaho Panhandle. What makes this situation a
little more difficult than usual is the key dendritic layer will
be far from saturated. In fact only the layer from -10 to -15c
will have any moisture that nears saturation. This could lead to
periods of light freezing drizzle across the northern valleys in
addition to periodic snow. Amounts will be fairly light. By later
this morning though...the precipitation trends will begin to
increase steadily.

This precipitation increase will result from a good influx of
sub-tropical moisture. As of 2am...water vapor imagery was showing
a deep atmospheric river extending from west of Hawaii almost to
the Washington coast. This plume is expected to surge over the
Cascades by afternoon and remain over the region through much of
the night as a warm front invades the region. The front will
contribute to the warming temperatures over most valley locations.
The exception will be in the lee of the Cascades due to cold air
damming. The damming is expected to hold cold air over the
Waterville Plateau...Okanogan Valley...Wenatchee area...and
Cascade Valleys. Most of these locations still look like they will
see snow throughout the event. Models are fairly consistent on
dropping anywhere from .60-1.20 inches near the Cascades between
now and Saturday morning with values from .30-.80 inches across
most of the Inland Northwest. The combination of cold air and
heavy precipitation equates to a very good chance of heavy snow.
Valleys in the Cascades could see anywhere from 5-10 inches of
snow...with heavier amounts over the mountains...especially near
the crest. From Wenatchee to the Okanogan valleys...snow amount
should generally range from 3 to 6 inches...however that`s
assuming all the precipitation falls as snow. That notion is far
from a slam dunk for Wenatchee...the Wenatchee River Valley...and
Waterville Plateau...as there are signs that a fairly small
elevated melting layer will push into this area late this
afternoon or this evening. This would either put a strong damper
on the production of snow...or lead to a period of freezing rain.
The SREF would hedge toward the latter. This is far from a
confident notion as there are significant model differences. The
NAM would move this wedge over these areas almost at the onset of
the event...whereas the EC and GFS hold off until late this
evening. Not sure which model to believe...however the NAM may be
onto something as its handling surface temperatures much better
compared to surface observations. There is a much lesser chance of
this warm wedge moving as far north as Lake Chelan or the Okanogan
Valley. Elsewhere...the event looks primarily like a rain
maker...with snow levels gradually climbing to 3-4k feet over
northeast Washington and the north Idaho Panhandle...and anywhere
from 4-5k feet over the central Panhandle. There will likely be a
transition from snow to rain in the surrounding valleys...with 1
to 3 inches of snow a distinct possibility. Locally heavier
amounts are possible in valley locations close to the Canadian
border including Bonners Ferry...Metaline Falls and Laurier. The
widespread stratiform precipitation associated with the warm front
will transition to an unstable regime with the passage of a
significant shortwave trough and associated cold front. The front
should pass through the Cascades overnight and into the Idaho
Panhandle by early morning.

The front will finally provide the focus for mixing out all the
valleys with moderate to locally strong winds associated with good
downward momentum per cold air advection. Enough moisture and
instability will remain in place for numerous snow showers
primarily over the Idaho Panhandle and near the Cascades crest.
Meanwhile the lee valleys of the Cascades...Columbia Basin...and
the Spokane area will see a drying trend. It`s interesting to note
that with the passage of the cold front we will see a good
atmospheric destabilization and the NAM is actually showing some
small CAPE values over the central Panhandle by afternoon and
evening. This suggests we could see a significant development of
post frontal showers accompanied by locally heavy snow rates.
Elsewhere the main issue will be winds. Looks like the area could
see speeds approach wind advisory levels with sustained speeds of
20-25 mph with gusts of 40 mph possible. The strongest winds are
expected over the southeast Columbia Basin and Palouse. Based on
the myriad of highlights out at this time...we will defer this
issue to future shifts...but will give mention in hazardous
weather outlook. The strong winds will mix out any semblance of
modified arctic air...resulting in warming temps. However when
factoring in the winds...it certainly won`t feel warmer. fx

Saturday night through Tuesday night: A parade of systems will
in the northwest flow will bring precipitation every other day or
so. This comes with the potential for an extended period of wet
weather starting Monday night or Tuesday, accompanied by milder
and perhaps slightly above seasonal normal temperatures. However
model agreement falters by this time frame and forecast confidence
is degraded.

Saturday night one system pulls east. This and the northwest flow
will keep the threat of snow alive across the Panhandle and
southeast WA through evening. Chances will wane overnight as the
system exits. At the same time the lingering threat of snow near
the Cascade crest in the onshore flow will be bolstered by the
moisture and lift increasing with the next warm front overnight.
Meanwhile the remainder of central and eastern WA will continue to
be plagued by low clouds, as well as a threat of patchy fog.

Sunday the warm front moves into eastern WA and north ID,
bringing the next round of snow and rain. Models have sped up the
start of precipitation for the morning, at least slightly. By
afternoon the trailing occluded front comes into central WA,
lessening the precipitation in the lee of the Cascades and western
Basin. Yet east of here the threat will remain high through
evening, due to the passing occluded front, a lingering theta-e
ridge that weakens near the ID/WA border and the northwest flow.
Within this region models place the higher precipitation amounts
over southeast WA through the central Panhandle. The threat
appears to gradually wane overnight as the feature weakens.

As for precipitation-type and amounts: in the morning snow will
be the predominate threat. Exceptions will be over the deeper
Columbia Basin and L-C Valley where rain will be more likely. By
afternoon the main snow threat backs into the Cascades and lifts
toward the northern WA and ID Panhandle mountains, while mainly
rain or a rain/snow mix will be more likely over the Columbia
Basin eastward to the lower elevations of the Panhandle. As
compared to Friday`s system, the lift is weaker and the moisture
tap is not as impressive. So precipitation amounts look lower. Yet
with that said they are still modest in some areas. While models
generally depict less than a tenth toward the lee of the Cascades
and western Basin, they show between a tenth and a quarter of inch
over the eastern Basin. Near half an inch is depicted in the
eastern mountains and near an inch near the Cascade crest. Falling
as snow this could result in more moderate to locally heavy snow
amounts around the mountains. Yet even the lower elevations could
see some accumulations; early total suggest maybe a half inch to
an inch, with local amounts near two in some of the northern
mountain valleys.

Between Monday and Tuesday the next weather maker arrives. There
are still some questions about the evolution of the system,
including precipitation amounts and type. Yet it has the potential
to be a wet and milder period. By Monday afternoon and evening the
next warm front lifts across the region. The associated surface
low tracks from the central BC coast Monday morning to northeast
MT Tuesday morning. However models do not indicate a strong push
from the north behind that low. This is due to yet another system
moving across the Gulf of Alaska into western BC by Tuesday, which
should stalling things. This latter feature keeps a quasi-
stationary front across northeast WA through the central Panhandle
Monday night into Tuesday. Furthermore models show at least two
smaller-scale low pressure centers moves along that stalled front,
a relatively weak one Tuesday morning and a stronger low pressure
center late Tuesday into Tuesday night. Furthermore models show
another good subtropical moisture tap. PWATs rise to between 0.50
and 0.85 inches by Tuesday (or between 130 to 225% of normal).

So this evolution suggests another round of precipitation. Its
precise evolution may easily change. Yet right now models suggest
precipitation developing first around the Cascades and northern
mountains Monday (albeit light), before expanding across the
eastern third of WA and the ID Panhandle Monday night into Tuesday
morning. Chances remain high into Tuesday night with precipitation
rates on the rise, especially if models continue to depict that
stronger low moving along the stalled front. There are caveats to
this high precipitation threat. In the continued west-northwest
flow models paint the highest precipitation amounts across the
Cascade crest and across the Idaho Panhandle, save for the places
like the L-C Valley. Yet in the lee of the Cascades and western
Basin the west-northwest flow may provide enough to keep things
drier, due to the downsloping/shadow effect, at least for at least
a portion of this period. The best threat of precipitation in the
region may come around Tuesday afternoon into Tuesday evening,
when that second strong low moves along that stall boundary. In
addition if the stalled boundary remains further north, then the
precipitation threat may be diminished away from the all but the
Cascades and northern mountains.

As for precipitation-type during this time frame: snow levels
look to be on the rise. Initially models keep colder air in place.
Snow levels are currently projected to be around 1500 to 3500
feet, lowest toward NE WA and north ID. However all models show
the jet stream lifting north and miler air surging in. Monday
night into Tuesday morning models show snow level rise to between
5000 and 8000 feet across the Cascades through southeast WA,
though they linger near 2500 to 4000 feet across northeast WA and
the ID Panhandle. Going into Tuesday afternoon and night models
push snow levels up to between 7000 to 8000 feet over much of the
region, with the main sticky point at this time toward the
Canadian border where some still keep them at low as 3000 feet. So
these will continue to be fine-tuned, I`m sure. Overall this means
the potential for snow early Monday, changes to primarily rain
Monday night into Tuesday, save for the potential for snow to
linger longer at lower elevations northern counties where
confidence is lower. /J. Cote`

Wednesday through Friday: While many are planning for a busy
Thanksgiving travel period, the forecast continues to hinder the
planning process as it remains up in the air at this point with
lots of uncertainty. Just as models started to come into some sort
of agreement earlier today, the latest ECMWF jumped off the deep
end depicting what the GFS was showing several runs ago. While the
latest Euro now shows a fair amount of ridging on the west coast
leading to warmer and drier conditions, the GFS continues to
bring cooler northwesterly flow onshore keeping temps a bit cooler
and the pattern a bit more active. Due to the large amount of
inconsistencies in model comparison and run to run evaluation,
very few changes were made to the forecast as it could have hurt
more than helped at this point. The main change was to raise
temperatures and in turn snow levels as well to values above most
valley floors throughout the extended leading to any precipitation
to fall as valley rain and mountain snow. Both the GFS and ECMWF
had wet bulb zero temps depicted much further north than
previously shown so the mentioned changes were made. POPs were
left essentially untouched and we will hope for considerable
improvements in model consistency in the near future to get a
better sense of what we can expect for the holiday period.
/Fliehman

&&

.AVIATION...
12Z TAFS: MVFR Ceilings and vis continues to be common over the
region this morning as a moist boundary layer and light winds
exists under a strong low level inversion...with a mix of MVFR to
LIFR conditions at the northern and western TAF sites. Downsloping
winds at KPUW and KLWS will keep them in the VFR category. A very
moist Pacific storm system will spread thickening clouds over the
region on Friday with -SN/-RA to develop aft 19z in KEAT and aft
23z at KGEG eastward. Pcpn will vary btwn -SN, -RA and -FZRA at
KEAT and could be moderate at times. Warmer conditions will bring
rain to KMWH/KGEG/KSFF/KCOE/KPUW/KLWS. Ceilings with the
precipitation are once again expected to drop to MVFR or even IFR
conditions. /Fliehman





&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        37  36  42  30  38  29 /  30 100  20  20  70  30
Coeur d`Alene  38  36  42  31  39  30 /  40 100  50  20  70  40
Pullman        42  37  44  33  41  31 /  10 100  70  50  70  60
Lewiston       46  41  48  36  46  34 /  10 100  60  30  60  40
Colville       36  34  42  23  37  23 /  90 100  20  10  60  20
Sandpoint      34  34  40  29  37  30 /  80 100  70  30  70  40
Kellogg        36  35  39  31  35  31 /  60 100  80  60  80  60
Moses Lake     36  33  47  28  44  29 /  90 100  10  10  30  10
Wenatchee      34  34  45  33  43  31 / 100 100  10  10  40  20
Omak           34  32  42  26  37  27 / 100 100  10  10  30  20

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Air Stagnation Advisory until Noon PST today for Central
     Panhandle Mountains-Coeur d`Alene Area-Idaho Palouse-
     Northern Panhandle.

     Winter Storm Warning from Noon today to 6 PM PST Saturday for
     Northern Panhandle.

     Winter Storm Warning from Noon today to 6 AM PST Sunday for
     Central Panhandle Mountains.

WA...Air Stagnation Advisory until Noon PST today for East Slopes
     Northern Cascades-Lower Garfield and Asotin Counties-Moses
     Lake Area-Northeast Mountains-Okanogan Highlands-Spokane
     Area-Upper Columbia Basin-Washington Palouse-Waterville
     Plateau-Wenatchee Area.

     Winter Storm Warning from Noon today to 6 AM PST Saturday for
     East Slopes Northern Cascades-Okanogan Highlands-Okanogan
     Valley-Waterville Plateau.

     Winter Storm Warning from Noon today to 6 PM PST Saturday for
     Northeast Mountains.

     Winter Weather Advisory from Noon today to 6 AM PST Saturday for
     Wenatchee Area.

&&

$$





000
FXUS66 KSEW 211156
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
356 AM PST FRI NOV 21 2014

.SYNOPSIS...A STRONG PACIFIC STORM WILL BRING GUSTY WINDS TO THE
AREA AND SNOW TO THE MOUNTAINS THROUGH TONIGHT. EXPECT THE
OCCLUDED FRONT TO SWEEP ACROSS THE REGION LATE TODAY THROUGH THIS
EVENING. UNSETTLED CONDITIONS WILL PREVAIL ON SATURDAY. ALAS...
ANOTHER LOW PRESSURE SYSTEM WILL IMPACT THE AREA ON SUNDAY FOR
MORE SNOW IN THE MOUNTAINS AND LOCALLY GUSTY WINDS.

&&

.SHORT TERM...
PRECIP WAS STARTING TO INCREASE ACROSS THE CWA AHEAD OF THE MAIN
PRECIP SHIELD THAT WAS STILL OFFSHORE AT THIS TIME. SATELLITE
DERIVED PRECIPITABLE WATER /PWAT/ IMAGERY SHOWED THAT THE VIGOROUS
PACIFIC STORM APPROACHING THE PACIFIC NORTHWEST HAS A DECENT
MOISTURE FEED OR PLUME ASSOCIATED WITH IT. THE SATELLITE DERIVED
PERCENT OF NORMAL TOTAL PRECIPITABLE WATER PRODUCT SHOWED THAT
THERE WERE AMOUNTS OVER 200 PERCENT OF NORMAL ASSOCIATED WITH THE
UPCOMING SYSTEM.

THE HEAVIEST PRECIP IS EXPECTED TO FALL ON THE COAST AND IN THE
MOUNTAINS...WHERE TOTAL LIQUID PRECIP AMOUNTS ARE EXPECTED TO BE
IN THE 1 TO 2.5 INCH RANGE DURING THE 24 HOUR PERIOD ENDING AT 4
AM PST SATURDAY. THE CASCADES ABOVE THE 3500 FOOT LEVEL IS
EXPECTED TO RECEIVE 10 TO 16 INCHES OF NEW SNOW BY SATURDAY
MORNING.

STRONG WESTERLY WINDS WILL ALSO HELP TO ENHANCE SNOWFALL AMOUNTS
IN THE CASCADES...SO THERE WILL LIKELY BE LOCALIZED HIGHER
AMOUNTS. ALSO...A PUGET SOUND CONVERGENCE ZONE /PSCZ/ IS EXPECTED
TO DEVELOP LATE TONIGHT OR EARLY SATURDAY AND THIS WILL RESULT
IN LOCALLY HEAVY SNOW IN THE CASCADES NEAR THE KING/SNOHOMISH
COUNTY LINE. THE SNOW LEVELS WILL BRIEFLY RISE LATER TODAY OR
EARLY THIS EVENING BEFORE PLUMMETING TO NEAR 3000 FEET EARLY
SATURDAY. WILL NEED TO KEEP AN EYE ON EXACTLY WHERE THE PSCZ WILL
FORM BECAUSE THERE IS A DISTINCT POSSIBILITY THAT SNOQUALMIE PASS
COULD RECEIVE LOW END ADVISORY CRITERIA SNOWFALL AMOUNTS /6 OR 7
INCHES/ ON SATURDAY.

OTHER THAN THE SNOW IN THE MOUNTAINS...ANTICIPATE GUSTY WINDS
AHEAD OF AND WITH THE OCCLUDED FRONT THAT WILL SWEEP ACROSS LATE
TODAY THROUGH THIS EVENING. A WIND ADVISORY WAS ISSUED FOR THE
MORE WIND PRONE AREAS...NAMELY THE COAST AND PARTS OF THE
NORTHWEST INTERIOR.

THE UPPER TROF WILL MOVE ACROSS THE REGION SATURDAY MORNING BUT
EMBEDDED DISTURBANCES WITHIN THE STRONG WESTERLY FLOW WILL SERVE
TO KEEP WEATHER CONDITIONS UNSETTLED ACROSS THE CWA ON SATURDAY.
THE BEST CHANCE OF PRECIP WILL BE OVER THE MOUNTAINS...COAST...AND
WITHIN THE PSCZ.

THERE MAY BE A BRIEF BREAK IN THE ACTION SATURDAY EVENING BETWEEN
SYSTEMS BUT CANNOT COMPLETELY COUNT ON IT. THE NEXT SYSTEM WILL
QUICKLY FOLLOW ON THE HEELS OF THE DEPARTING ONE...WITH STEADY
PRECIP REDEVELOPING SATURDAY NIGHT. THIS NEXT SYSTEM WILL BE A
FAST ONE...THUS EXPECT THE COLD OR OCCLUDED FRONT TO SWEEP ACROSS
THE CWA LATE SUNDAY MORNING OR EARLY SUNDAY AFTERNOON. SHOWERY
CONDITIONS SHOULD PREVAIL SUNDAY AFTERNOON IN THE WAKE OF THE
FRONT. THE CASCADES ABOVE 3500 FEET CAN EXPECT TO RECEIVE ANOTHER
9 TO 15 INCHES OF NEW SNOW FROM THIS SYSTEM.

.LONG TERM...
CONFIDENCE IN THIS PERIOD WAS NOT HIGH DUE TO LACK OF AGREEMENT
BETWEEN THE MEDIUM RANGE SOLUTIONS AS WELL AS LACK OF RUN TO RUN
CONSISTENCY IN THE MODELS. EITHER THERE WILL BE AN UPPER TROF OVER
THE REGION OR AN UPPER RIDGE. DECIDED TO LEAVE THE INHERITED
FORECAST PRETTY MUCH INTACT.

&&

.HYDROLOGY...
RIVER FLOODING IS NOT EXPECTED THE NEXT 7 DAYS.

&&

.AVIATION...WESTERLY FLOW ALOFT AS A STRONG FRONTAL SYSTEM
APPROACHES THE COAST. THE AIR MASS IS MOIST AND STABLE EXCEPT FOR
ISOLATED SHOWERS NORTH PART. RAIN FROM THE APPROACHING FRONT WILL
SPREAD INLAND AROUND 15Z. THE FRONT WILL REACH THE COAST AROUND 00Z
AND PUGET SOUND AROUND 04Z. AT THE SURFACE STRONG GUSTY SOUTHEAST
WINDS WILL DEVELOP ALONG THE COAST AND OVER PARTS OF THE NORTH
INTERIOR THIS AFTERNOON AND CONTINUE INTO THE EVENING.

CEILINGS ARE GENERALLY VFR 4K-6K FT. CEILINGS WILL FALL TO MVFR
2K-3K FT IN RAIN 12Z-15Z AND STAY THERE ALL DAY. CEILINGS WILL NOT
IMPROVE MUCH TONIGHT IN ONSHORE SURFACE FLOW AND A SHOWERY PATTERN.

KSEA...DISCUSSION ABOVE APPLIES. WINDS SOUTHEAST 5-9 KT. RAIN AND
MVFR CONDITIONS WILL PREDOMINATE TODAY. WINDS WILL RISE TO SOUTHERLY
8-12 KT IN THE AFTERNOON. CHB

&&

.MARINE...A STRONG FRONTAL SYSTEM WILL MOVE THROUGH THE AREA TODAY.
GALE WARNINGS ARE UP FOR THE COASTAL WATERS AND THE EAST ENTRANCE
AND NORTH INLAND WATERS WITH SMALL CRAFT ADVISORIES ELSEWHERE.
FRONTAL PASSAGE ALONG THE COAST SHOULD BE AROUND 00Z...THEN AROUND
04Z OVER PUGET SOUND. A WESTERLY PUSH BEHIND THE FRONT WILL PRODUCE
SMALL CRAFT ADVISORY WEST WINDS THROUGH THE STRAIT...THOUGH A BRIEF
GALE IS ALSO POSSIBLE.

ANOTHER SYSTEM ON SUNDAY IS GAINING STRENGTH IN THE MODELS. THIS
COULD GIVE GALES ON THE COAST AND DOWN THE STRAIT. SWELLS IN THE
15-20 FOOT RANGE ARE FORECAST TO REACH THE COAST SUNDAY. CHB

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...WIND ADVISORIES ARE IN EFFECT FOR THE COAST AND PARTS OF THE
     NORTHWEST INTERIOR.

     WINTER WEATHER ADVISORY IN EFFECT FOR THE CASCADES ABOVE 3500
     FEET FROM 10 AM UNTIL 6 AM SATURDAY.

PZ...GALE WARNING IN EFFECT UNTIL 10 PM TONIGHT FOR THE COASTAL
     WATERS...EAST ENTRANCE TO THE STRAIT OF JUAN DE FUCA...AND
     THE NORTHERN INLAND WATERS.

     SMALL CRAFT ADVISORIES ARE IN EFFECT FOR THE REMAINING WATERS.

     SMALL CRAFT ADVISORY IN EFFECT FOR ROUGH BAR UNTIL 10 AM
     SATURDAY FOR THE GRAYS HARBOR BAR.

&&

$$

WWW.WEATHER.GOV/SEATTLE

YOU CAN SEE AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML




000
FXUS66 KSEW 211156
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
356 AM PST FRI NOV 21 2014

.SYNOPSIS...A STRONG PACIFIC STORM WILL BRING GUSTY WINDS TO THE
AREA AND SNOW TO THE MOUNTAINS THROUGH TONIGHT. EXPECT THE
OCCLUDED FRONT TO SWEEP ACROSS THE REGION LATE TODAY THROUGH THIS
EVENING. UNSETTLED CONDITIONS WILL PREVAIL ON SATURDAY. ALAS...
ANOTHER LOW PRESSURE SYSTEM WILL IMPACT THE AREA ON SUNDAY FOR
MORE SNOW IN THE MOUNTAINS AND LOCALLY GUSTY WINDS.

&&

.SHORT TERM...
PRECIP WAS STARTING TO INCREASE ACROSS THE CWA AHEAD OF THE MAIN
PRECIP SHIELD THAT WAS STILL OFFSHORE AT THIS TIME. SATELLITE
DERIVED PRECIPITABLE WATER /PWAT/ IMAGERY SHOWED THAT THE VIGOROUS
PACIFIC STORM APPROACHING THE PACIFIC NORTHWEST HAS A DECENT
MOISTURE FEED OR PLUME ASSOCIATED WITH IT. THE SATELLITE DERIVED
PERCENT OF NORMAL TOTAL PRECIPITABLE WATER PRODUCT SHOWED THAT
THERE WERE AMOUNTS OVER 200 PERCENT OF NORMAL ASSOCIATED WITH THE
UPCOMING SYSTEM.

THE HEAVIEST PRECIP IS EXPECTED TO FALL ON THE COAST AND IN THE
MOUNTAINS...WHERE TOTAL LIQUID PRECIP AMOUNTS ARE EXPECTED TO BE
IN THE 1 TO 2.5 INCH RANGE DURING THE 24 HOUR PERIOD ENDING AT 4
AM PST SATURDAY. THE CASCADES ABOVE THE 3500 FOOT LEVEL IS
EXPECTED TO RECEIVE 10 TO 16 INCHES OF NEW SNOW BY SATURDAY
MORNING.

STRONG WESTERLY WINDS WILL ALSO HELP TO ENHANCE SNOWFALL AMOUNTS
IN THE CASCADES...SO THERE WILL LIKELY BE LOCALIZED HIGHER
AMOUNTS. ALSO...A PUGET SOUND CONVERGENCE ZONE /PSCZ/ IS EXPECTED
TO DEVELOP LATE TONIGHT OR EARLY SATURDAY AND THIS WILL RESULT
IN LOCALLY HEAVY SNOW IN THE CASCADES NEAR THE KING/SNOHOMISH
COUNTY LINE. THE SNOW LEVELS WILL BRIEFLY RISE LATER TODAY OR
EARLY THIS EVENING BEFORE PLUMMETING TO NEAR 3000 FEET EARLY
SATURDAY. WILL NEED TO KEEP AN EYE ON EXACTLY WHERE THE PSCZ WILL
FORM BECAUSE THERE IS A DISTINCT POSSIBILITY THAT SNOQUALMIE PASS
COULD RECEIVE LOW END ADVISORY CRITERIA SNOWFALL AMOUNTS /6 OR 7
INCHES/ ON SATURDAY.

OTHER THAN THE SNOW IN THE MOUNTAINS...ANTICIPATE GUSTY WINDS
AHEAD OF AND WITH THE OCCLUDED FRONT THAT WILL SWEEP ACROSS LATE
TODAY THROUGH THIS EVENING. A WIND ADVISORY WAS ISSUED FOR THE
MORE WIND PRONE AREAS...NAMELY THE COAST AND PARTS OF THE
NORTHWEST INTERIOR.

THE UPPER TROF WILL MOVE ACROSS THE REGION SATURDAY MORNING BUT
EMBEDDED DISTURBANCES WITHIN THE STRONG WESTERLY FLOW WILL SERVE
TO KEEP WEATHER CONDITIONS UNSETTLED ACROSS THE CWA ON SATURDAY.
THE BEST CHANCE OF PRECIP WILL BE OVER THE MOUNTAINS...COAST...AND
WITHIN THE PSCZ.

THERE MAY BE A BRIEF BREAK IN THE ACTION SATURDAY EVENING BETWEEN
SYSTEMS BUT CANNOT COMPLETELY COUNT ON IT. THE NEXT SYSTEM WILL
QUICKLY FOLLOW ON THE HEELS OF THE DEPARTING ONE...WITH STEADY
PRECIP REDEVELOPING SATURDAY NIGHT. THIS NEXT SYSTEM WILL BE A
FAST ONE...THUS EXPECT THE COLD OR OCCLUDED FRONT TO SWEEP ACROSS
THE CWA LATE SUNDAY MORNING OR EARLY SUNDAY AFTERNOON. SHOWERY
CONDITIONS SHOULD PREVAIL SUNDAY AFTERNOON IN THE WAKE OF THE
FRONT. THE CASCADES ABOVE 3500 FEET CAN EXPECT TO RECEIVE ANOTHER
9 TO 15 INCHES OF NEW SNOW FROM THIS SYSTEM.

.LONG TERM...
CONFIDENCE IN THIS PERIOD WAS NOT HIGH DUE TO LACK OF AGREEMENT
BETWEEN THE MEDIUM RANGE SOLUTIONS AS WELL AS LACK OF RUN TO RUN
CONSISTENCY IN THE MODELS. EITHER THERE WILL BE AN UPPER TROF OVER
THE REGION OR AN UPPER RIDGE. DECIDED TO LEAVE THE INHERITED
FORECAST PRETTY MUCH INTACT.

&&

.HYDROLOGY...
RIVER FLOODING IS NOT EXPECTED THE NEXT 7 DAYS.

&&

.AVIATION...WESTERLY FLOW ALOFT AS A STRONG FRONTAL SYSTEM
APPROACHES THE COAST. THE AIR MASS IS MOIST AND STABLE EXCEPT FOR
ISOLATED SHOWERS NORTH PART. RAIN FROM THE APPROACHING FRONT WILL
SPREAD INLAND AROUND 15Z. THE FRONT WILL REACH THE COAST AROUND 00Z
AND PUGET SOUND AROUND 04Z. AT THE SURFACE STRONG GUSTY SOUTHEAST
WINDS WILL DEVELOP ALONG THE COAST AND OVER PARTS OF THE NORTH
INTERIOR THIS AFTERNOON AND CONTINUE INTO THE EVENING.

CEILINGS ARE GENERALLY VFR 4K-6K FT. CEILINGS WILL FALL TO MVFR
2K-3K FT IN RAIN 12Z-15Z AND STAY THERE ALL DAY. CEILINGS WILL NOT
IMPROVE MUCH TONIGHT IN ONSHORE SURFACE FLOW AND A SHOWERY PATTERN.

KSEA...DISCUSSION ABOVE APPLIES. WINDS SOUTHEAST 5-9 KT. RAIN AND
MVFR CONDITIONS WILL PREDOMINATE TODAY. WINDS WILL RISE TO SOUTHERLY
8-12 KT IN THE AFTERNOON. CHB

&&

.MARINE...A STRONG FRONTAL SYSTEM WILL MOVE THROUGH THE AREA TODAY.
GALE WARNINGS ARE UP FOR THE COASTAL WATERS AND THE EAST ENTRANCE
AND NORTH INLAND WATERS WITH SMALL CRAFT ADVISORIES ELSEWHERE.
FRONTAL PASSAGE ALONG THE COAST SHOULD BE AROUND 00Z...THEN AROUND
04Z OVER PUGET SOUND. A WESTERLY PUSH BEHIND THE FRONT WILL PRODUCE
SMALL CRAFT ADVISORY WEST WINDS THROUGH THE STRAIT...THOUGH A BRIEF
GALE IS ALSO POSSIBLE.

ANOTHER SYSTEM ON SUNDAY IS GAINING STRENGTH IN THE MODELS. THIS
COULD GIVE GALES ON THE COAST AND DOWN THE STRAIT. SWELLS IN THE
15-20 FOOT RANGE ARE FORECAST TO REACH THE COAST SUNDAY. CHB

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...WIND ADVISORIES ARE IN EFFECT FOR THE COAST AND PARTS OF THE
     NORTHWEST INTERIOR.

     WINTER WEATHER ADVISORY IN EFFECT FOR THE CASCADES ABOVE 3500
     FEET FROM 10 AM UNTIL 6 AM SATURDAY.

PZ...GALE WARNING IN EFFECT UNTIL 10 PM TONIGHT FOR THE COASTAL
     WATERS...EAST ENTRANCE TO THE STRAIT OF JUAN DE FUCA...AND
     THE NORTHERN INLAND WATERS.

     SMALL CRAFT ADVISORIES ARE IN EFFECT FOR THE REMAINING WATERS.

     SMALL CRAFT ADVISORY IN EFFECT FOR ROUGH BAR UNTIL 10 AM
     SATURDAY FOR THE GRAYS HARBOR BAR.

&&

$$

WWW.WEATHER.GOV/SEATTLE

YOU CAN SEE AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML





000
FXUS66 KOTX 211128
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
328 AM PST FRI NOV 21 2014

.SYNOPSIS...
A relatively quiet and cool overnight period with a few snow
showers over the north will give way to a sharp deterioration in
the weather on Friday as a strong and moist Pacific storm brings
valley rain and mountain snow Friday night followed by very windy
conditions on Saturday. An active and periodically wet weather
regime will continue through the next week.

&&

.DISCUSSION...
..BIGGEST SNOW MAKER SO FAR THIS  SEASON TO HIT MUCH OF THE INLAND
NORTHWEST LATER TODAY THROUGH SATURDAY...

Today and tonight ...Right now is the calm before the storm over
the Inland Northwest. All the region will see this morning is
some light precipitation in advance of a much wetter system
scheduled to move in later today. The 285k isentropic surface
continues to depict a fairly steep north-south pressure profile.
And this will become increasingly important this morning...as the
flow back toward more of a southerly orientation. This should make
light precipitation a little more widespread this
morning...especially over the northern third of Washington and the
northern half of the Idaho Panhandle. What makes this situation a
little more difficult than usual is the key dendritic layer will
be far from saturated. In fact only the layer from -10 to -15c
will have any moisture that nears saturation. This could lead to
periods of light freezing drizzle across the northern valleys in
addition to periodic snow. Amounts will be fairly light. By later
this morning though...the precipitation trends will begin to
increase steadily.

This precipitation increase will result from a good influx of
sub-tropical moisture. As of 2am...water vapor imagery was showing
a deep atmospheric river extending from west of Hawaii almost to
the Washington coast. This plume is expected to surge over the
Cascades by afternoon and remain over the region through much of
the night as a warm front invades the region. The front will
contribute to the warming temperatures over most valley locations.
The exception will be in the lee of the Cascades due to cold air
damming. The damming is expected to hold cold air over the
Waterville Plateau...Okanogan Valley...Wenatchee area...and
Cascade Valleys. Most of these locations still look like they will
see snow throughout the event. Models are fairly consistent on
dropping anywhere from .60-1.20 inches near the Cascades between
now and Saturday morning with values from .30-.80 inches across
most of the Inland Northwest. The combination of cold air and
heavy precipitation equates to a very good chance of heavy snow.
Valleys in the Cascades could see anywhere from 5-10 inches of
snow...with heavier amounts over the mountains...especially near
the crest. From Wenatchee to the Okanogan valleys...snow amount
should generally range from 3 to 6 inches...however that`s
assuming all the precipitation falls as snow. That notion is far
from a slam dunk for Wenatchee...the Wenatchee River Valley...and
Waterville Plateau...as there are signs that a fairly small
elevated melting layer will push into this area late this
afternoon or this evening. This would either put a strong damper
on the production of snow...or lead to a period of freezing rain.
The SREF would hedge toward the latter. This is far from a
confident notion as there are significant model differences. The
NAM would move this wedge over these areas almost at the onset of
the event...whereas the EC and GFS hold off until late this
evening. Not sure which model to believe...however the NAM may be
onto something as its handling surface temperatures much better
compared to surface observations. There is a much lesser chance of
this warm wedge moving as far north as Lake Chelan or the Okanogan
Valley. Elsewhere...the event looks primarily like a rain
maker...with snow levels gradually climbing to 3-4k feet over
northeast Washington and the north Idaho Panhandle...and anywhere
from 4-5k feet over the central Panhandle. There will likely be a
transition from snow to rain in the surrounding valleys...with 1
to 3 inches of snow a distinct possibility. Locally heavier
amounts are possible in valley locations close to the Canadian
border including Bonners Ferry...Metaline Falls and Laurier. The
widespread stratiform precipitation associated with the warm front
will transition to an unstable regime with the passage of a
significant shortwave trough and associated cold front. The front
should pass through the Cascades overnight and into the Idaho
Panhandle by early morning.

The front will finally provide the focus for mixing out all the
valleys with moderate to locally strong winds associated with good
downward momentum per cold air advection. Enough moisture and
instability will remain in place for numerous snow showers
primarily over the Idaho Panhandle and near the Cascades crest.
Meanwhile the lee valleys of the Cascades...Columbia Basin...and
the Spokane area will see a drying trend. It`s interesting to note
that with the passage of the cold front we will see a good
atmospheric destabilization and the NAM is actually showing some
small CAPE values over the central Panhandle by afternoon and
evening. This suggests we could see a significant development of
post frontal showers accompanied by locally heavy snow rates.
Elsewhere the main issue will be winds. Looks like the area could
see speeds approach wind advisory levels with sustained speeds of
20-25 mph with gusts of 40 mph possible. The strongest winds are
expected over the southeast Columbia Basin and Palouse. Based on
the myriad of highlights out at this time...we will defer this
issue to future shifts...but will give mention in hazardous
weather outlook. The strong winds will mix out any semblance of
modified arctic air...resulting in warming temps. However when
factoring in the winds...it certainly won`t feel warmer. fx

Saturday night through Tuesday night: A parade of systems will
in the northwest flow will bring precipitation every other day or
so. This comes with the potential for an extended period of wet
weather starting Monday night or Tuesday, accompanied by milder
and perhaps slightly above seasonal normal temperatures. However
model agreement falters by this time frame and forecast confidence
is degraded.

Saturday night one system pulls east. This and the northwest flow
will keep the threat of snow alive across the Panhandle and
southeast WA through evening. Chances will wane overnight as the
system exits. At the same time the lingering threat of snow near
the Cascade crest in the onshore flow will be bolstered by the
moisture and lift increasing with the next warm front overnight.
Meanwhile the remainder of central and eastern WA will continue to
be plagued by low clouds, as well as a threat of patchy fog.

Sunday the warm front moves into eastern WA and north ID,
bringing the next round of snow and rain. Models have sped up the
start of precipitation for the morning, at least slightly. By
afternoon the trailing occluded front comes into central WA,
lessening the precipitation in the lee of the Cascades and western
Basin. Yet east of here the threat will remain high through
evening, due to the passing occluded front, a lingering theta-e
ridge that weakens near the ID/WA border and the northwest flow.
Within this region models place the higher precipitation amounts
over southeast WA through the central Panhandle. The threat
appears to gradually wane overnight as the feature weakens.

As for precipitation-type and amounts: in the morning snow will
be the predominate threat. Exceptions will be over the deeper
Columbia Basin and L-C Valley where rain will be more likely. By
afternoon the main snow threat backs into the Cascades and lifts
toward the northern WA and ID Panhandle mountains, while mainly
rain or a rain/snow mix will be more likely over the Columbia
Basin eastward to the lower elevations of the Panhandle. As
compared to Friday`s system, the lift is weaker and the moisture
tap is not as impressive. So precipitation amounts look lower. Yet
with that said they are still modest in some areas. While models
generally depict less than a tenth toward the lee of the Cascades
and western Basin, they show between a tenth and a quarter of inch
over the eastern Basin. Near half an inch is depicted in the
eastern mountains and near an inch near the Cascade crest. Falling
as snow this could result in more moderate to locally heavy snow
amounts around the mountains. Yet even the lower elevations could
see some accumulations; early total suggest maybe a half inch to
an inch, with local amounts near two in some of the northern
mountain valleys.

Between Monday and Tuesday the next weather maker arrives. There
are still some questions about the evolution of the system,
including precipitation amounts and type. Yet it has the potential
to be a wet and milder period. By Monday afternoon and evening the
next warm front lifts across the region. The associated surface
low tracks from the central BC coast Monday morning to northeast
MT Tuesday morning. However models do not indicate a strong push
from the north behind that low. This is due to yet another system
moving across the Gulf of Alaska into western BC by Tuesday, which
should stalling things. This latter feature keeps a quasi-
stationary front across northeast WA through the central Panhandle
Monday night into Tuesday. Furthermore models show at least two
smaller-scale low pressure centers moves along that stalled front,
a relatively weak one Tuesday morning and a stronger low pressure
center late Tuesday into Tuesday night. Furthermore models show
another good subtropical moisture tap. PWATs rise to between 0.50
and 0.85 inches by Tuesday (or between 130 to 225% of normal).

So this evolution suggests another round of precipitation. Its
precise evolution may easily change. Yet right now models suggest
precipitation developing first around the Cascades and northern
mountains Monday (albeit light), before expanding across the
eastern third of WA and the ID Panhandle Monday night into Tuesday
morning. Chances remain high into Tuesday night with precipitation
rates on the rise, especially if models continue to depict that
stronger low moving along the stalled front. There are caveats to
this high precipitation threat. In the continued west-northwest
flow models paint the highest precipitation amounts across the
Cascade crest and across the Idaho Panhandle, save for the places
like the L-C Valley. Yet in the lee of the Cascades and western
Basin the west-northwest flow may provide enough to keep things
drier, due to the downsloping/shadow effect, at least for at least
a portion of this period. The best threat of precipitation in the
region may come around Tuesday afternoon into Tuesday evening,
when that second strong low moves along that stall boundary. In
addition if the stalled boundary remains further north, then the
precipitation threat may be diminished away from the all but the
Cascades and northern mountains.

As for precipitation-type during this time frame: snow levels
look to be on the rise. Initially models keep colder air in place.
Snow levels are currently projected to be around 1500 to 3500
feet, lowest toward NE WA and north ID. However all models show
the jet stream lifting north and miler air surging in. Monday
night into Tuesday morning models show snow level rise to between
5000 and 8000 feet across the Cascades through southeast WA,
though they linger near 2500 to 4000 feet across northeast WA and
the ID Panhandle. Going into Tuesday afternoon and night models
push snow levels up to between 7000 to 8000 feet over much of the
region, with the main sticky point at this time toward the
Canadian border where some still keep them at low as 3000 feet. So
these will continue to be fine-tuned, I`m sure. Overall this means
the potential for snow early Monday, changes to primarily rain
Monday night into Tuesday, save for the potential for snow to
linger longer at lower elevations northern counties where
confidence is lower. /J. Cote`

Wednesday through Friday: While many are planning for a busy
Thanksgiving travel period, the forecast continues to hinder the
planning process as it remains up in the air at this point with
lots of uncertainty. Just as models started to come into some sort
of agreement earlier today, the latest ECMWF jumped off the deep
end depicting what the GFS was showing several runs ago. While the
latest Euro now shows a fair amount of ridging on the west coast
leading to warmer and drier conditions, the GFS continues to
bring cooler northwesterly flow onshore keeping temps a bit cooler
and the pattern a bit more active. Due to the large amount of
inconsistencies in model comparison and run to run evaluation,
very few changes were made to the forecast as it could have hurt
more than helped at this point. The main change was to raise
temperatures and in turn snow levels as well to values above most
valley floors throughout the extended leading to any precipitation
to fall as valley rain and mountain snow. Both the GFS and ECMWF
had wet bulb zero temps depicted much further north than
previously shown so the mentioned changes were made. POPs were
left essentially untouched and we will hope for considerable
improvements in model consistency in the near future to get a
better sense of what we can expect for the holiday period.
/Fliehman

&&

.AVIATION...
06Z TAFS: MVFR Ceilings and vis will be common over the region
through tomorrow morning as a moist boundary layer and light
winds exists under a strong low level inversion...with a mix of
MVFR and IFR conditions. Increasing lift into the moist boundary
layer will also bring a small chance for spotty freezing drizzle.
A moist Pacific storm system will spread thickening clouds over
the region on Friday with -SN/-RA to develop aft 18z in KEAT and
aft 00z at KGEG. Pcpn will vary btwn -SN and -FZRA at KEAT and
could be moderate at times. Warmer conditions will bring mostly
rain to KMWH/KGEG-KCOE/KPUW/KLWS. Breezy southerly winds and
lighter pcpn will keep KPUW/KLWS VFR conditions. /sb





&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        37  36  42  30  38  29 /  30 100  20  20  70  30
Coeur d`Alene  38  36  42  31  39  30 /  40 100  50  20  70  40
Pullman        42  37  44  33  41  31 /  10 100  70  50  70  60
Lewiston       46  41  48  36  46  34 /  10 100  60  30  60  40
Colville       36  34  42  23  37  23 /  90 100  20  10  60  20
Sandpoint      34  34  40  29  37  30 /  80 100  70  30  70  40
Kellogg        36  35  39  31  35  31 /  60 100  80  60  80  60
Moses Lake     36  33  47  28  44  29 /  90 100  10  10  30  10
Wenatchee      34  34  45  33  43  31 / 100 100  10  10  40  20
Omak           34  32  42  26  37  27 / 100 100  10  10  30  20

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Air Stagnation Advisory until Noon PST today for Central
     Panhandle Mountains-Coeur d`Alene Area-Idaho Palouse-
     Northern Panhandle.

     Winter Storm Warning from Noon today to 6 PM PST Saturday for
     Northern Panhandle.

     Winter Storm Warning from Noon today to 6 AM PST Sunday for
     Central Panhandle Mountains.

WA...Air Stagnation Advisory until Noon PST today for East Slopes
     Northern Cascades-Lower Garfield and Asotin Counties-Moses
     Lake Area-Northeast Mountains-Okanogan Highlands-Spokane
     Area-Upper Columbia Basin-Washington Palouse-Waterville
     Plateau-Wenatchee Area.

     Winter Storm Warning from Noon today to 6 AM PST Saturday for
     East Slopes Northern Cascades-Okanogan Highlands-Okanogan
     Valley-Waterville Plateau.

     Winter Storm Warning from Noon today to 6 PM PST Saturday for
     Northeast Mountains.

     Winter Weather Advisory from Noon today to 6 AM PST Saturday for
     Wenatchee Area.

&&

$$





000
FXUS66 KOTX 211128
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
328 AM PST FRI NOV 21 2014

.SYNOPSIS...
A relatively quiet and cool overnight period with a few snow
showers over the north will give way to a sharp deterioration in
the weather on Friday as a strong and moist Pacific storm brings
valley rain and mountain snow Friday night followed by very windy
conditions on Saturday. An active and periodically wet weather
regime will continue through the next week.

&&

.DISCUSSION...
..BIGGEST SNOW MAKER SO FAR THIS  SEASON TO HIT MUCH OF THE INLAND
NORTHWEST LATER TODAY THROUGH SATURDAY...

Today and tonight ...Right now is the calm before the storm over
the Inland Northwest. All the region will see this morning is
some light precipitation in advance of a much wetter system
scheduled to move in later today. The 285k isentropic surface
continues to depict a fairly steep north-south pressure profile.
And this will become increasingly important this morning...as the
flow back toward more of a southerly orientation. This should make
light precipitation a little more widespread this
morning...especially over the northern third of Washington and the
northern half of the Idaho Panhandle. What makes this situation a
little more difficult than usual is the key dendritic layer will
be far from saturated. In fact only the layer from -10 to -15c
will have any moisture that nears saturation. This could lead to
periods of light freezing drizzle across the northern valleys in
addition to periodic snow. Amounts will be fairly light. By later
this morning though...the precipitation trends will begin to
increase steadily.

This precipitation increase will result from a good influx of
sub-tropical moisture. As of 2am...water vapor imagery was showing
a deep atmospheric river extending from west of Hawaii almost to
the Washington coast. This plume is expected to surge over the
Cascades by afternoon and remain over the region through much of
the night as a warm front invades the region. The front will
contribute to the warming temperatures over most valley locations.
The exception will be in the lee of the Cascades due to cold air
damming. The damming is expected to hold cold air over the
Waterville Plateau...Okanogan Valley...Wenatchee area...and
Cascade Valleys. Most of these locations still look like they will
see snow throughout the event. Models are fairly consistent on
dropping anywhere from .60-1.20 inches near the Cascades between
now and Saturday morning with values from .30-.80 inches across
most of the Inland Northwest. The combination of cold air and
heavy precipitation equates to a very good chance of heavy snow.
Valleys in the Cascades could see anywhere from 5-10 inches of
snow...with heavier amounts over the mountains...especially near
the crest. From Wenatchee to the Okanogan valleys...snow amount
should generally range from 3 to 6 inches...however that`s
assuming all the precipitation falls as snow. That notion is far
from a slam dunk for Wenatchee...the Wenatchee River Valley...and
Waterville Plateau...as there are signs that a fairly small
elevated melting layer will push into this area late this
afternoon or this evening. This would either put a strong damper
on the production of snow...or lead to a period of freezing rain.
The SREF would hedge toward the latter. This is far from a
confident notion as there are significant model differences. The
NAM would move this wedge over these areas almost at the onset of
the event...whereas the EC and GFS hold off until late this
evening. Not sure which model to believe...however the NAM may be
onto something as its handling surface temperatures much better
compared to surface observations. There is a much lesser chance of
this warm wedge moving as far north as Lake Chelan or the Okanogan
Valley. Elsewhere...the event looks primarily like a rain
maker...with snow levels gradually climbing to 3-4k feet over
northeast Washington and the north Idaho Panhandle...and anywhere
from 4-5k feet over the central Panhandle. There will likely be a
transition from snow to rain in the surrounding valleys...with 1
to 3 inches of snow a distinct possibility. Locally heavier
amounts are possible in valley locations close to the Canadian
border including Bonners Ferry...Metaline Falls and Laurier. The
widespread stratiform precipitation associated with the warm front
will transition to an unstable regime with the passage of a
significant shortwave trough and associated cold front. The front
should pass through the Cascades overnight and into the Idaho
Panhandle by early morning.

The front will finally provide the focus for mixing out all the
valleys with moderate to locally strong winds associated with good
downward momentum per cold air advection. Enough moisture and
instability will remain in place for numerous snow showers
primarily over the Idaho Panhandle and near the Cascades crest.
Meanwhile the lee valleys of the Cascades...Columbia Basin...and
the Spokane area will see a drying trend. It`s interesting to note
that with the passage of the cold front we will see a good
atmospheric destabilization and the NAM is actually showing some
small CAPE values over the central Panhandle by afternoon and
evening. This suggests we could see a significant development of
post frontal showers accompanied by locally heavy snow rates.
Elsewhere the main issue will be winds. Looks like the area could
see speeds approach wind advisory levels with sustained speeds of
20-25 mph with gusts of 40 mph possible. The strongest winds are
expected over the southeast Columbia Basin and Palouse. Based on
the myriad of highlights out at this time...we will defer this
issue to future shifts...but will give mention in hazardous
weather outlook. The strong winds will mix out any semblance of
modified arctic air...resulting in warming temps. However when
factoring in the winds...it certainly won`t feel warmer. fx

Saturday night through Tuesday night: A parade of systems will
in the northwest flow will bring precipitation every other day or
so. This comes with the potential for an extended period of wet
weather starting Monday night or Tuesday, accompanied by milder
and perhaps slightly above seasonal normal temperatures. However
model agreement falters by this time frame and forecast confidence
is degraded.

Saturday night one system pulls east. This and the northwest flow
will keep the threat of snow alive across the Panhandle and
southeast WA through evening. Chances will wane overnight as the
system exits. At the same time the lingering threat of snow near
the Cascade crest in the onshore flow will be bolstered by the
moisture and lift increasing with the next warm front overnight.
Meanwhile the remainder of central and eastern WA will continue to
be plagued by low clouds, as well as a threat of patchy fog.

Sunday the warm front moves into eastern WA and north ID,
bringing the next round of snow and rain. Models have sped up the
start of precipitation for the morning, at least slightly. By
afternoon the trailing occluded front comes into central WA,
lessening the precipitation in the lee of the Cascades and western
Basin. Yet east of here the threat will remain high through
evening, due to the passing occluded front, a lingering theta-e
ridge that weakens near the ID/WA border and the northwest flow.
Within this region models place the higher precipitation amounts
over southeast WA through the central Panhandle. The threat
appears to gradually wane overnight as the feature weakens.

As for precipitation-type and amounts: in the morning snow will
be the predominate threat. Exceptions will be over the deeper
Columbia Basin and L-C Valley where rain will be more likely. By
afternoon the main snow threat backs into the Cascades and lifts
toward the northern WA and ID Panhandle mountains, while mainly
rain or a rain/snow mix will be more likely over the Columbia
Basin eastward to the lower elevations of the Panhandle. As
compared to Friday`s system, the lift is weaker and the moisture
tap is not as impressive. So precipitation amounts look lower. Yet
with that said they are still modest in some areas. While models
generally depict less than a tenth toward the lee of the Cascades
and western Basin, they show between a tenth and a quarter of inch
over the eastern Basin. Near half an inch is depicted in the
eastern mountains and near an inch near the Cascade crest. Falling
as snow this could result in more moderate to locally heavy snow
amounts around the mountains. Yet even the lower elevations could
see some accumulations; early total suggest maybe a half inch to
an inch, with local amounts near two in some of the northern
mountain valleys.

Between Monday and Tuesday the next weather maker arrives. There
are still some questions about the evolution of the system,
including precipitation amounts and type. Yet it has the potential
to be a wet and milder period. By Monday afternoon and evening the
next warm front lifts across the region. The associated surface
low tracks from the central BC coast Monday morning to northeast
MT Tuesday morning. However models do not indicate a strong push
from the north behind that low. This is due to yet another system
moving across the Gulf of Alaska into western BC by Tuesday, which
should stalling things. This latter feature keeps a quasi-
stationary front across northeast WA through the central Panhandle
Monday night into Tuesday. Furthermore models show at least two
smaller-scale low pressure centers moves along that stalled front,
a relatively weak one Tuesday morning and a stronger low pressure
center late Tuesday into Tuesday night. Furthermore models show
another good subtropical moisture tap. PWATs rise to between 0.50
and 0.85 inches by Tuesday (or between 130 to 225% of normal).

So this evolution suggests another round of precipitation. Its
precise evolution may easily change. Yet right now models suggest
precipitation developing first around the Cascades and northern
mountains Monday (albeit light), before expanding across the
eastern third of WA and the ID Panhandle Monday night into Tuesday
morning. Chances remain high into Tuesday night with precipitation
rates on the rise, especially if models continue to depict that
stronger low moving along the stalled front. There are caveats to
this high precipitation threat. In the continued west-northwest
flow models paint the highest precipitation amounts across the
Cascade crest and across the Idaho Panhandle, save for the places
like the L-C Valley. Yet in the lee of the Cascades and western
Basin the west-northwest flow may provide enough to keep things
drier, due to the downsloping/shadow effect, at least for at least
a portion of this period. The best threat of precipitation in the
region may come around Tuesday afternoon into Tuesday evening,
when that second strong low moves along that stall boundary. In
addition if the stalled boundary remains further north, then the
precipitation threat may be diminished away from the all but the
Cascades and northern mountains.

As for precipitation-type during this time frame: snow levels
look to be on the rise. Initially models keep colder air in place.
Snow levels are currently projected to be around 1500 to 3500
feet, lowest toward NE WA and north ID. However all models show
the jet stream lifting north and miler air surging in. Monday
night into Tuesday morning models show snow level rise to between
5000 and 8000 feet across the Cascades through southeast WA,
though they linger near 2500 to 4000 feet across northeast WA and
the ID Panhandle. Going into Tuesday afternoon and night models
push snow levels up to between 7000 to 8000 feet over much of the
region, with the main sticky point at this time toward the
Canadian border where some still keep them at low as 3000 feet. So
these will continue to be fine-tuned, I`m sure. Overall this means
the potential for snow early Monday, changes to primarily rain
Monday night into Tuesday, save for the potential for snow to
linger longer at lower elevations northern counties where
confidence is lower. /J. Cote`

Wednesday through Friday: While many are planning for a busy
Thanksgiving travel period, the forecast continues to hinder the
planning process as it remains up in the air at this point with
lots of uncertainty. Just as models started to come into some sort
of agreement earlier today, the latest ECMWF jumped off the deep
end depicting what the GFS was showing several runs ago. While the
latest Euro now shows a fair amount of ridging on the west coast
leading to warmer and drier conditions, the GFS continues to
bring cooler northwesterly flow onshore keeping temps a bit cooler
and the pattern a bit more active. Due to the large amount of
inconsistencies in model comparison and run to run evaluation,
very few changes were made to the forecast as it could have hurt
more than helped at this point. The main change was to raise
temperatures and in turn snow levels as well to values above most
valley floors throughout the extended leading to any precipitation
to fall as valley rain and mountain snow. Both the GFS and ECMWF
had wet bulb zero temps depicted much further north than
previously shown so the mentioned changes were made. POPs were
left essentially untouched and we will hope for considerable
improvements in model consistency in the near future to get a
better sense of what we can expect for the holiday period.
/Fliehman

&&

.AVIATION...
06Z TAFS: MVFR Ceilings and vis will be common over the region
through tomorrow morning as a moist boundary layer and light
winds exists under a strong low level inversion...with a mix of
MVFR and IFR conditions. Increasing lift into the moist boundary
layer will also bring a small chance for spotty freezing drizzle.
A moist Pacific storm system will spread thickening clouds over
the region on Friday with -SN/-RA to develop aft 18z in KEAT and
aft 00z at KGEG. Pcpn will vary btwn -SN and -FZRA at KEAT and
could be moderate at times. Warmer conditions will bring mostly
rain to KMWH/KGEG-KCOE/KPUW/KLWS. Breezy southerly winds and
lighter pcpn will keep KPUW/KLWS VFR conditions. /sb





&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        37  36  42  30  38  29 /  30 100  20  20  70  30
Coeur d`Alene  38  36  42  31  39  30 /  40 100  50  20  70  40
Pullman        42  37  44  33  41  31 /  10 100  70  50  70  60
Lewiston       46  41  48  36  46  34 /  10 100  60  30  60  40
Colville       36  34  42  23  37  23 /  90 100  20  10  60  20
Sandpoint      34  34  40  29  37  30 /  80 100  70  30  70  40
Kellogg        36  35  39  31  35  31 /  60 100  80  60  80  60
Moses Lake     36  33  47  28  44  29 /  90 100  10  10  30  10
Wenatchee      34  34  45  33  43  31 / 100 100  10  10  40  20
Omak           34  32  42  26  37  27 / 100 100  10  10  30  20

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Air Stagnation Advisory until Noon PST today for Central
     Panhandle Mountains-Coeur d`Alene Area-Idaho Palouse-
     Northern Panhandle.

     Winter Storm Warning from Noon today to 6 PM PST Saturday for
     Northern Panhandle.

     Winter Storm Warning from Noon today to 6 AM PST Sunday for
     Central Panhandle Mountains.

WA...Air Stagnation Advisory until Noon PST today for East Slopes
     Northern Cascades-Lower Garfield and Asotin Counties-Moses
     Lake Area-Northeast Mountains-Okanogan Highlands-Spokane
     Area-Upper Columbia Basin-Washington Palouse-Waterville
     Plateau-Wenatchee Area.

     Winter Storm Warning from Noon today to 6 AM PST Saturday for
     East Slopes Northern Cascades-Okanogan Highlands-Okanogan
     Valley-Waterville Plateau.

     Winter Storm Warning from Noon today to 6 PM PST Saturday for
     Northeast Mountains.

     Winter Weather Advisory from Noon today to 6 AM PST Saturday for
     Wenatchee Area.

&&

$$




000
FXUS66 KOTX 211128
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
328 AM PST FRI NOV 21 2014

.SYNOPSIS...
A relatively quiet and cool overnight period with a few snow
showers over the north will give way to a sharp deterioration in
the weather on Friday as a strong and moist Pacific storm brings
valley rain and mountain snow Friday night followed by very windy
conditions on Saturday. An active and periodically wet weather
regime will continue through the next week.

&&

.DISCUSSION...
..BIGGEST SNOW MAKER SO FAR THIS  SEASON TO HIT MUCH OF THE INLAND
NORTHWEST LATER TODAY THROUGH SATURDAY...

Today and tonight ...Right now is the calm before the storm over
the Inland Northwest. All the region will see this morning is
some light precipitation in advance of a much wetter system
scheduled to move in later today. The 285k isentropic surface
continues to depict a fairly steep north-south pressure profile.
And this will become increasingly important this morning...as the
flow back toward more of a southerly orientation. This should make
light precipitation a little more widespread this
morning...especially over the northern third of Washington and the
northern half of the Idaho Panhandle. What makes this situation a
little more difficult than usual is the key dendritic layer will
be far from saturated. In fact only the layer from -10 to -15c
will have any moisture that nears saturation. This could lead to
periods of light freezing drizzle across the northern valleys in
addition to periodic snow. Amounts will be fairly light. By later
this morning though...the precipitation trends will begin to
increase steadily.

This precipitation increase will result from a good influx of
sub-tropical moisture. As of 2am...water vapor imagery was showing
a deep atmospheric river extending from west of Hawaii almost to
the Washington coast. This plume is expected to surge over the
Cascades by afternoon and remain over the region through much of
the night as a warm front invades the region. The front will
contribute to the warming temperatures over most valley locations.
The exception will be in the lee of the Cascades due to cold air
damming. The damming is expected to hold cold air over the
Waterville Plateau...Okanogan Valley...Wenatchee area...and
Cascade Valleys. Most of these locations still look like they will
see snow throughout the event. Models are fairly consistent on
dropping anywhere from .60-1.20 inches near the Cascades between
now and Saturday morning with values from .30-.80 inches across
most of the Inland Northwest. The combination of cold air and
heavy precipitation equates to a very good chance of heavy snow.
Valleys in the Cascades could see anywhere from 5-10 inches of
snow...with heavier amounts over the mountains...especially near
the crest. From Wenatchee to the Okanogan valleys...snow amount
should generally range from 3 to 6 inches...however that`s
assuming all the precipitation falls as snow. That notion is far
from a slam dunk for Wenatchee...the Wenatchee River Valley...and
Waterville Plateau...as there are signs that a fairly small
elevated melting layer will push into this area late this
afternoon or this evening. This would either put a strong damper
on the production of snow...or lead to a period of freezing rain.
The SREF would hedge toward the latter. This is far from a
confident notion as there are significant model differences. The
NAM would move this wedge over these areas almost at the onset of
the event...whereas the EC and GFS hold off until late this
evening. Not sure which model to believe...however the NAM may be
onto something as its handling surface temperatures much better
compared to surface observations. There is a much lesser chance of
this warm wedge moving as far north as Lake Chelan or the Okanogan
Valley. Elsewhere...the event looks primarily like a rain
maker...with snow levels gradually climbing to 3-4k feet over
northeast Washington and the north Idaho Panhandle...and anywhere
from 4-5k feet over the central Panhandle. There will likely be a
transition from snow to rain in the surrounding valleys...with 1
to 3 inches of snow a distinct possibility. Locally heavier
amounts are possible in valley locations close to the Canadian
border including Bonners Ferry...Metaline Falls and Laurier. The
widespread stratiform precipitation associated with the warm front
will transition to an unstable regime with the passage of a
significant shortwave trough and associated cold front. The front
should pass through the Cascades overnight and into the Idaho
Panhandle by early morning.

The front will finally provide the focus for mixing out all the
valleys with moderate to locally strong winds associated with good
downward momentum per cold air advection. Enough moisture and
instability will remain in place for numerous snow showers
primarily over the Idaho Panhandle and near the Cascades crest.
Meanwhile the lee valleys of the Cascades...Columbia Basin...and
the Spokane area will see a drying trend. It`s interesting to note
that with the passage of the cold front we will see a good
atmospheric destabilization and the NAM is actually showing some
small CAPE values over the central Panhandle by afternoon and
evening. This suggests we could see a significant development of
post frontal showers accompanied by locally heavy snow rates.
Elsewhere the main issue will be winds. Looks like the area could
see speeds approach wind advisory levels with sustained speeds of
20-25 mph with gusts of 40 mph possible. The strongest winds are
expected over the southeast Columbia Basin and Palouse. Based on
the myriad of highlights out at this time...we will defer this
issue to future shifts...but will give mention in hazardous
weather outlook. The strong winds will mix out any semblance of
modified arctic air...resulting in warming temps. However when
factoring in the winds...it certainly won`t feel warmer. fx

Saturday night through Tuesday night: A parade of systems will
in the northwest flow will bring precipitation every other day or
so. This comes with the potential for an extended period of wet
weather starting Monday night or Tuesday, accompanied by milder
and perhaps slightly above seasonal normal temperatures. However
model agreement falters by this time frame and forecast confidence
is degraded.

Saturday night one system pulls east. This and the northwest flow
will keep the threat of snow alive across the Panhandle and
southeast WA through evening. Chances will wane overnight as the
system exits. At the same time the lingering threat of snow near
the Cascade crest in the onshore flow will be bolstered by the
moisture and lift increasing with the next warm front overnight.
Meanwhile the remainder of central and eastern WA will continue to
be plagued by low clouds, as well as a threat of patchy fog.

Sunday the warm front moves into eastern WA and north ID,
bringing the next round of snow and rain. Models have sped up the
start of precipitation for the morning, at least slightly. By
afternoon the trailing occluded front comes into central WA,
lessening the precipitation in the lee of the Cascades and western
Basin. Yet east of here the threat will remain high through
evening, due to the passing occluded front, a lingering theta-e
ridge that weakens near the ID/WA border and the northwest flow.
Within this region models place the higher precipitation amounts
over southeast WA through the central Panhandle. The threat
appears to gradually wane overnight as the feature weakens.

As for precipitation-type and amounts: in the morning snow will
be the predominate threat. Exceptions will be over the deeper
Columbia Basin and L-C Valley where rain will be more likely. By
afternoon the main snow threat backs into the Cascades and lifts
toward the northern WA and ID Panhandle mountains, while mainly
rain or a rain/snow mix will be more likely over the Columbia
Basin eastward to the lower elevations of the Panhandle. As
compared to Friday`s system, the lift is weaker and the moisture
tap is not as impressive. So precipitation amounts look lower. Yet
with that said they are still modest in some areas. While models
generally depict less than a tenth toward the lee of the Cascades
and western Basin, they show between a tenth and a quarter of inch
over the eastern Basin. Near half an inch is depicted in the
eastern mountains and near an inch near the Cascade crest. Falling
as snow this could result in more moderate to locally heavy snow
amounts around the mountains. Yet even the lower elevations could
see some accumulations; early total suggest maybe a half inch to
an inch, with local amounts near two in some of the northern
mountain valleys.

Between Monday and Tuesday the next weather maker arrives. There
are still some questions about the evolution of the system,
including precipitation amounts and type. Yet it has the potential
to be a wet and milder period. By Monday afternoon and evening the
next warm front lifts across the region. The associated surface
low tracks from the central BC coast Monday morning to northeast
MT Tuesday morning. However models do not indicate a strong push
from the north behind that low. This is due to yet another system
moving across the Gulf of Alaska into western BC by Tuesday, which
should stalling things. This latter feature keeps a quasi-
stationary front across northeast WA through the central Panhandle
Monday night into Tuesday. Furthermore models show at least two
smaller-scale low pressure centers moves along that stalled front,
a relatively weak one Tuesday morning and a stronger low pressure
center late Tuesday into Tuesday night. Furthermore models show
another good subtropical moisture tap. PWATs rise to between 0.50
and 0.85 inches by Tuesday (or between 130 to 225% of normal).

So this evolution suggests another round of precipitation. Its
precise evolution may easily change. Yet right now models suggest
precipitation developing first around the Cascades and northern
mountains Monday (albeit light), before expanding across the
eastern third of WA and the ID Panhandle Monday night into Tuesday
morning. Chances remain high into Tuesday night with precipitation
rates on the rise, especially if models continue to depict that
stronger low moving along the stalled front. There are caveats to
this high precipitation threat. In the continued west-northwest
flow models paint the highest precipitation amounts across the
Cascade crest and across the Idaho Panhandle, save for the places
like the L-C Valley. Yet in the lee of the Cascades and western
Basin the west-northwest flow may provide enough to keep things
drier, due to the downsloping/shadow effect, at least for at least
a portion of this period. The best threat of precipitation in the
region may come around Tuesday afternoon into Tuesday evening,
when that second strong low moves along that stall boundary. In
addition if the stalled boundary remains further north, then the
precipitation threat may be diminished away from the all but the
Cascades and northern mountains.

As for precipitation-type during this time frame: snow levels
look to be on the rise. Initially models keep colder air in place.
Snow levels are currently projected to be around 1500 to 3500
feet, lowest toward NE WA and north ID. However all models show
the jet stream lifting north and miler air surging in. Monday
night into Tuesday morning models show snow level rise to between
5000 and 8000 feet across the Cascades through southeast WA,
though they linger near 2500 to 4000 feet across northeast WA and
the ID Panhandle. Going into Tuesday afternoon and night models
push snow levels up to between 7000 to 8000 feet over much of the
region, with the main sticky point at this time toward the
Canadian border where some still keep them at low as 3000 feet. So
these will continue to be fine-tuned, I`m sure. Overall this means
the potential for snow early Monday, changes to primarily rain
Monday night into Tuesday, save for the potential for snow to
linger longer at lower elevations northern counties where
confidence is lower. /J. Cote`

Wednesday through Friday: While many are planning for a busy
Thanksgiving travel period, the forecast continues to hinder the
planning process as it remains up in the air at this point with
lots of uncertainty. Just as models started to come into some sort
of agreement earlier today, the latest ECMWF jumped off the deep
end depicting what the GFS was showing several runs ago. While the
latest Euro now shows a fair amount of ridging on the west coast
leading to warmer and drier conditions, the GFS continues to
bring cooler northwesterly flow onshore keeping temps a bit cooler
and the pattern a bit more active. Due to the large amount of
inconsistencies in model comparison and run to run evaluation,
very few changes were made to the forecast as it could have hurt
more than helped at this point. The main change was to raise
temperatures and in turn snow levels as well to values above most
valley floors throughout the extended leading to any precipitation
to fall as valley rain and mountain snow. Both the GFS and ECMWF
had wet bulb zero temps depicted much further north than
previously shown so the mentioned changes were made. POPs were
left essentially untouched and we will hope for considerable
improvements in model consistency in the near future to get a
better sense of what we can expect for the holiday period.
/Fliehman

&&

.AVIATION...
06Z TAFS: MVFR Ceilings and vis will be common over the region
through tomorrow morning as a moist boundary layer and light
winds exists under a strong low level inversion...with a mix of
MVFR and IFR conditions. Increasing lift into the moist boundary
layer will also bring a small chance for spotty freezing drizzle.
A moist Pacific storm system will spread thickening clouds over
the region on Friday with -SN/-RA to develop aft 18z in KEAT and
aft 00z at KGEG. Pcpn will vary btwn -SN and -FZRA at KEAT and
could be moderate at times. Warmer conditions will bring mostly
rain to KMWH/KGEG-KCOE/KPUW/KLWS. Breezy southerly winds and
lighter pcpn will keep KPUW/KLWS VFR conditions. /sb





&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        37  36  42  30  38  29 /  30 100  20  20  70  30
Coeur d`Alene  38  36  42  31  39  30 /  40 100  50  20  70  40
Pullman        42  37  44  33  41  31 /  10 100  70  50  70  60
Lewiston       46  41  48  36  46  34 /  10 100  60  30  60  40
Colville       36  34  42  23  37  23 /  90 100  20  10  60  20
Sandpoint      34  34  40  29  37  30 /  80 100  70  30  70  40
Kellogg        36  35  39  31  35  31 /  60 100  80  60  80  60
Moses Lake     36  33  47  28  44  29 /  90 100  10  10  30  10
Wenatchee      34  34  45  33  43  31 / 100 100  10  10  40  20
Omak           34  32  42  26  37  27 / 100 100  10  10  30  20

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Air Stagnation Advisory until Noon PST today for Central
     Panhandle Mountains-Coeur d`Alene Area-Idaho Palouse-
     Northern Panhandle.

     Winter Storm Warning from Noon today to 6 PM PST Saturday for
     Northern Panhandle.

     Winter Storm Warning from Noon today to 6 AM PST Sunday for
     Central Panhandle Mountains.

WA...Air Stagnation Advisory until Noon PST today for East Slopes
     Northern Cascades-Lower Garfield and Asotin Counties-Moses
     Lake Area-Northeast Mountains-Okanogan Highlands-Spokane
     Area-Upper Columbia Basin-Washington Palouse-Waterville
     Plateau-Wenatchee Area.

     Winter Storm Warning from Noon today to 6 AM PST Saturday for
     East Slopes Northern Cascades-Okanogan Highlands-Okanogan
     Valley-Waterville Plateau.

     Winter Storm Warning from Noon today to 6 PM PST Saturday for
     Northeast Mountains.

     Winter Weather Advisory from Noon today to 6 AM PST Saturday for
     Wenatchee Area.

&&

$$




000
FXUS66 KPQR 211127
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
323 AM PST FRI NOV 21 2014

CORRECTED WATCHES/WARNINGS/ADVISORIES SECTION.

.SYNOPSIS...MORE TYPICAL FALL WATHER IN STORE FOR SOUTHWEST
WASHINGTON AND NORTHWEST OREGON TODAY. COOLER AIR BEHIND THIS SYSTEM
WILL CAUSE THE SNOW LEVELS TO LOWER BELOW THE CASCADE PASSES EARLY
SATURDAY WHILE STRONG ONSHORE FLOW CONTINUES THROUGH THE WEEKEND. AS
A RESULT SNOW MAY BECOME HEAVY AT TIMES ALL THE WAY DOWN TO PASS
LEVELS THIS WEEKEND. ANOTHER SYSTEM IS LIKELY TO AFFECT THE REGION
EARLY NEXT WEEK...THEN PERHAPS SOME DRIER WEATHER BY MIDWEEK.

&&

.SHORT TERM...MORE MILD FALL WEATHER ON THE WAY. THE NEXT DEVELOPING
SYSTEM ARRIVES TODAY AS A STRONG FRONTAL SYSTEM TRAILING ALONG THE
NORTH PACIFIC 150 KT JETSTREAM. THE WARM FRONT PORTION WILL REACH
THE COAST THIS MORNING WITH THE TRAILING COLD FRONT ARRIVING THIS
AFTERNOON AND MOVING EAST OF THE CASCADES OVERNIGHT.
WIND...COASTAL WINDS LOOK MARGINAL FOR HIGH WINDS BUT BELIEVE THE
NORTH AND CENTRAL OREGON COAST HAVE THE BEST CHANCE FOR GUSTS TO 60
MPH AT THE BEACHES AND HEADLANDS.  PEAK WINDS ARE EXPECTED IN THE
MID TO LATE AFTERNOON. 850 MB AND 950 MB WINDS ALIGN ALONG THE COAST
JUST AS THE SURFACE GRADIENT PATTERN BECOMES FAVORABLE...A SHORT
WINDOW.   THE ECMWF DEEPENS THE LOW ON THE FRONT MORE THAN NAM AND
GFS...BUT PLACES IT CLOSER THE THE SOUTH WASHINGTON COAST.INLAND
VALLEYS WILL BECOME BREEZY LATE IN THE AFTERNOON AND EARLY EVENING.
GUSTS ARE EXPECTED TO REMAIN BELOW ANY ADVISORY OR WARNING CRITERIA.

COLUMBIA RIVER GORGE AND HOOD RIVER VALLEY...THE SHALLOW COLD AIR
MASS HAS NOT COOLED VERY MUCH OVERNIGHT.  MOST TEMPERATURES ARE
HOVERING A DEGREE OR TWO AROUND THE FREEZING MARK WITH ABOVE
FREEZING TEMPERATURES ALONG THE RIVER. TIMING OF THE PCPN AND
EXPECTED WARMING WILL LIKELY LIMIT FREEZING PRECIPITATION TO THE
UPPER HOOD RIVER VALLEY FOR THE MORNING HOURS.  ACCUMULATIONS AND
COVERAGE WILL NOT BE WIDESPREAD AS EARLIER THIS WEEK.

SNOW...SNOW LEVELS WILL INCREASE ABOVE ALL BUT THE HIGHEST PEAKS IN
THE AREA TODAY AS THE WARM FRONT APPROACHES. SNOW LEVELS WILL CRASH
TO AROUND 3000 TO 4000 FT SATURDAY MORNING. OROGRAPHICS BECOME
FAVORABLE IN THIS COLDER AIR MASS. 850 MB WINDS ARE WESTERLY 25 TO
45 KT SAT ALONG WITH ABUNDANT SHOWERS. SNOW WILL BE HEAVIER AT TIMES
AS IMPULSES MOVE THROUGH. IT APPEARS THE PERIOD OF HIGHER SNOWFALL
ACCUMULATION WILL BE SAT INTO EARLY SUN. THIS PERIOD MAY END UP
NEEDING A WINTER WEATHER ADVISORY.  CURRENT SPECIAL WEATHER
STATEMENT COVERS THIS UNTIL THEN.

RAIN AMOUNTS...A BATCH OF HEAVY RAIN TO PUSH INLAND DURING THE LATE
AFTERNOON AND EVENING...WITH 1.5 TO 2 INCHES OF RAIN LIKELY FOR THE
COAST...COAST RANGE AND CASCADES OVER ABOUT A 12 HR PERIOD ENDING
TONIGHT. THE INTERIOR LOWLANDS WILL BE CLOSER TO AN INCH. IT DOES NOT
APPEAR THAT RAINFALL TOTALS WILL BE ENOUGH TO CAUSE ANY FLOODING
CONCERNS.

CONVECTION...500 MB TEMPERATURES DROP TO AROUND -25 TO -30 C ON
SATURDAY. LIFTED INDEX LOWERS TO AROUND 0 TO -2. THERE IS ALSO A WEAK
VORT MAX THAT MOVES THROUGH DURING THE DAY TO ASSIST IN THE
INSTABILITY. SO HAVE ADDED A SLIGHT CHANCE OF THUNDERSTORMS OVER THE
WATERS AND INLAND TO THE COAST RANGE. THE INTERIOR LOWLAND MAY NEED
TO BE ADDED AS WELL...BUT THREAT APPEARS TOO LOW AT THIS TIME.

ALSO FOR THIS MORNING AREAS OF DENSE FOG DEVELOPED IN THE CENTRAL AND
SOUTH WILLAMETTE VALLEY OVERNIGHT BUT IS BEGINNING TO LIFT AS SO WILL
END THE DENSE FOG ADVISORY.  /26


.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY. THE MORE WESTERLY OR
ZONAL FLOW THAT SETS UP OVER THE WEEKEND DURING THE LATTER PART OF
THE SHORT TERM PERIOD BEGINS TO BUCKLE A BIT IN THE EARLY PART OF
THE LONG TERM PERIOD WITH SOME FLAT RIDGING DEVELOPING OVER THE
NORTHEAST PACIFIC. HAVE DECIDED TO CONTINUE TO STICK MORE WITH A
DIRTY RIDGE SCENARIO OF THE ECMWF VS THE HIGHER AMPLITUDE RIDGING OF
THE OPERATIONAL GFS MODEL. CONFIDENCE DECREASES THROUGHOUT THE LONG
TERM PERIOD AS MODEL VARIABILITY INCREASES...THOUGH THE TREND IS
TOWARD DRIER DURING THE MIDDLE TO LATTER PARTS OF NEXT WEEK. TOLLESON

&&

.AVIATION...EXPECT A VARIETY OF FLIGHT CONDITIONS TODAY AHEAD OF
AN APPROACHING FRONTAL SYSTEM. A MIX OF MVFR AND VFR WILL PERSIST
ALONG THE COAST...WITH MVFR CONDITIONS PREVAILING AFTER 14Z THIS
MORNING AS RAIN INCREASES. INLAND LOCATIONS WILL ALSO SEE
INCREASING MVFR CONDITIONS IN RAIN BETWEEN 16-18Z TODAY. THE MAIN
EXCEPTION WILL BE FOR THE CENTRAL AND SOUTHERN WILLAMETTE VALLEY
WHERE IFR AND LIFR FOG/LOW STRATUS WILL PERSIST THROUGH MUCH OF
TODAY...POSSIBLY LIFTING TO LOW END MVFR AFTER 21Z TODAY WHEN
SOUTHERLY WINDS PICK UP.

KPDX AND APPROACHES...VFR CONTINUES THROUGH AT LEAST 16Z THIS
MORNING BEFORE INCREASING RAIN DROPS CONDITIONS TO MVFR BY 18Z
THROUGH TONIGHT. LLWS POSSIBLE AT KPDX AND ERN APPROACHES THIS
AFTERNOON WITH E TO SE SURFACE AND 30-40 KT S-SW WIND AT FL 020
BASED ON MODEL SOUNDINGS. WEISHAAR/27

&&

.MARINE...SOUTHERLY WINDS WILL CONTINUE TO HOVER RIGHT NEAR SMALL
CRAFT ADVISORY CRITERIA WITH GUSTS NEAR 25 KT THROUGH THIS
MORNING. THE NEXT FRONTAL SYSTEM WILL BRING SOLID GALE FORCE WINDS
ACROSS ALL OF THE WATERS BY 18Z TODAY...WITH STRONGEST WINDS FROM
21Z FRI-03Z SAT OVER THE INNER COASTAL WATERS. 06Z MODELS HAVE
BACKED OFF A BIT ON WIND SPEEDS SO HAVE REPLACED THE STORM WATCH
WITH A GALE WARNING FOR THE WATERS 10 NM FROM THE SHORELINE. STILL
A FEW GUSTS NEAR 50 KT ARE POSSIBLE THIS AFTERNOON WITH A COASTAL
JET SITUATION. WIND SPEEDS SUBSIDE BY 06Z TONIGHT...AND WILL
REMAIN IN SMALL CRAFT ADVISORY CRITERIA THROUGH MUCH OF THE
WEEKEND.

SEAS AT 10 FT WILL CONTINUE EARLY TODAY...BEFORE QUICKLY BUILDING
BY NOON TODAY WITH THE STRONG GALE FORCE WIND CONDITIONS. COULD
GET CLOSE TO 20 FEET LATE FRI AFTERNOON THROUGH THE EVENING...BUT
WITH A LARGE WIND- WAVE COMPONENT. WAVE HEIGHTS DROP OFF TONIGHT
BEHIND THE COLD FRONT AND AS WIND SPEEDS WEAKEN. HOWEVER...SEAS
LOOK TO REMAIN ABOVE 10 FT THROUGH THIS WEEKEND. WEISHAAR/27

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...DENSE FOG ADVISORY UNTIL 9 AM PST THIS MORNING FOR CENTRAL
     WILLAMETTE VALLEY-SOUTH WILLAMETTE VALLEY.

     HIGH WIND WARNING FROM NOON PST TODAY THROUGH THIS EVENING FOR
     CENTRAL OREGON COAST-NORTH OREGON COAST.

WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 10 AM PST THIS MORNING FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     GALE WARNING FROM 10 AM THIS MORNING TO 10 PM PST THIS EVENING
     FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR
     OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 AM PST THIS
     MORNING FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
     FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 6 AM
     PST EARLY THIS MORNING...THEN AGAIN FROM NOON TODAY TO
     10 PM PST THIS EVENING.

&&

$$

INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND

THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.



000
FXUS66 KPQR 211127
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
323 AM PST FRI NOV 21 2014

CORRECTED WATCHES/WARNINGS/ADVISORIES SECTION.

.SYNOPSIS...MORE TYPICAL FALL WATHER IN STORE FOR SOUTHWEST
WASHINGTON AND NORTHWEST OREGON TODAY. COOLER AIR BEHIND THIS SYSTEM
WILL CAUSE THE SNOW LEVELS TO LOWER BELOW THE CASCADE PASSES EARLY
SATURDAY WHILE STRONG ONSHORE FLOW CONTINUES THROUGH THE WEEKEND. AS
A RESULT SNOW MAY BECOME HEAVY AT TIMES ALL THE WAY DOWN TO PASS
LEVELS THIS WEEKEND. ANOTHER SYSTEM IS LIKELY TO AFFECT THE REGION
EARLY NEXT WEEK...THEN PERHAPS SOME DRIER WEATHER BY MIDWEEK.

&&

.SHORT TERM...MORE MILD FALL WEATHER ON THE WAY. THE NEXT DEVELOPING
SYSTEM ARRIVES TODAY AS A STRONG FRONTAL SYSTEM TRAILING ALONG THE
NORTH PACIFIC 150 KT JETSTREAM. THE WARM FRONT PORTION WILL REACH
THE COAST THIS MORNING WITH THE TRAILING COLD FRONT ARRIVING THIS
AFTERNOON AND MOVING EAST OF THE CASCADES OVERNIGHT.
WIND...COASTAL WINDS LOOK MARGINAL FOR HIGH WINDS BUT BELIEVE THE
NORTH AND CENTRAL OREGON COAST HAVE THE BEST CHANCE FOR GUSTS TO 60
MPH AT THE BEACHES AND HEADLANDS.  PEAK WINDS ARE EXPECTED IN THE
MID TO LATE AFTERNOON. 850 MB AND 950 MB WINDS ALIGN ALONG THE COAST
JUST AS THE SURFACE GRADIENT PATTERN BECOMES FAVORABLE...A SHORT
WINDOW.   THE ECMWF DEEPENS THE LOW ON THE FRONT MORE THAN NAM AND
GFS...BUT PLACES IT CLOSER THE THE SOUTH WASHINGTON COAST.INLAND
VALLEYS WILL BECOME BREEZY LATE IN THE AFTERNOON AND EARLY EVENING.
GUSTS ARE EXPECTED TO REMAIN BELOW ANY ADVISORY OR WARNING CRITERIA.

COLUMBIA RIVER GORGE AND HOOD RIVER VALLEY...THE SHALLOW COLD AIR
MASS HAS NOT COOLED VERY MUCH OVERNIGHT.  MOST TEMPERATURES ARE
HOVERING A DEGREE OR TWO AROUND THE FREEZING MARK WITH ABOVE
FREEZING TEMPERATURES ALONG THE RIVER. TIMING OF THE PCPN AND
EXPECTED WARMING WILL LIKELY LIMIT FREEZING PRECIPITATION TO THE
UPPER HOOD RIVER VALLEY FOR THE MORNING HOURS.  ACCUMULATIONS AND
COVERAGE WILL NOT BE WIDESPREAD AS EARLIER THIS WEEK.

SNOW...SNOW LEVELS WILL INCREASE ABOVE ALL BUT THE HIGHEST PEAKS IN
THE AREA TODAY AS THE WARM FRONT APPROACHES. SNOW LEVELS WILL CRASH
TO AROUND 3000 TO 4000 FT SATURDAY MORNING. OROGRAPHICS BECOME
FAVORABLE IN THIS COLDER AIR MASS. 850 MB WINDS ARE WESTERLY 25 TO
45 KT SAT ALONG WITH ABUNDANT SHOWERS. SNOW WILL BE HEAVIER AT TIMES
AS IMPULSES MOVE THROUGH. IT APPEARS THE PERIOD OF HIGHER SNOWFALL
ACCUMULATION WILL BE SAT INTO EARLY SUN. THIS PERIOD MAY END UP
NEEDING A WINTER WEATHER ADVISORY.  CURRENT SPECIAL WEATHER
STATEMENT COVERS THIS UNTIL THEN.

RAIN AMOUNTS...A BATCH OF HEAVY RAIN TO PUSH INLAND DURING THE LATE
AFTERNOON AND EVENING...WITH 1.5 TO 2 INCHES OF RAIN LIKELY FOR THE
COAST...COAST RANGE AND CASCADES OVER ABOUT A 12 HR PERIOD ENDING
TONIGHT. THE INTERIOR LOWLANDS WILL BE CLOSER TO AN INCH. IT DOES NOT
APPEAR THAT RAINFALL TOTALS WILL BE ENOUGH TO CAUSE ANY FLOODING
CONCERNS.

CONVECTION...500 MB TEMPERATURES DROP TO AROUND -25 TO -30 C ON
SATURDAY. LIFTED INDEX LOWERS TO AROUND 0 TO -2. THERE IS ALSO A WEAK
VORT MAX THAT MOVES THROUGH DURING THE DAY TO ASSIST IN THE
INSTABILITY. SO HAVE ADDED A SLIGHT CHANCE OF THUNDERSTORMS OVER THE
WATERS AND INLAND TO THE COAST RANGE. THE INTERIOR LOWLAND MAY NEED
TO BE ADDED AS WELL...BUT THREAT APPEARS TOO LOW AT THIS TIME.

ALSO FOR THIS MORNING AREAS OF DENSE FOG DEVELOPED IN THE CENTRAL AND
SOUTH WILLAMETTE VALLEY OVERNIGHT BUT IS BEGINNING TO LIFT AS SO WILL
END THE DENSE FOG ADVISORY.  /26


.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY. THE MORE WESTERLY OR
ZONAL FLOW THAT SETS UP OVER THE WEEKEND DURING THE LATTER PART OF
THE SHORT TERM PERIOD BEGINS TO BUCKLE A BIT IN THE EARLY PART OF
THE LONG TERM PERIOD WITH SOME FLAT RIDGING DEVELOPING OVER THE
NORTHEAST PACIFIC. HAVE DECIDED TO CONTINUE TO STICK MORE WITH A
DIRTY RIDGE SCENARIO OF THE ECMWF VS THE HIGHER AMPLITUDE RIDGING OF
THE OPERATIONAL GFS MODEL. CONFIDENCE DECREASES THROUGHOUT THE LONG
TERM PERIOD AS MODEL VARIABILITY INCREASES...THOUGH THE TREND IS
TOWARD DRIER DURING THE MIDDLE TO LATTER PARTS OF NEXT WEEK. TOLLESON

&&

.AVIATION...EXPECT A VARIETY OF FLIGHT CONDITIONS TODAY AHEAD OF
AN APPROACHING FRONTAL SYSTEM. A MIX OF MVFR AND VFR WILL PERSIST
ALONG THE COAST...WITH MVFR CONDITIONS PREVAILING AFTER 14Z THIS
MORNING AS RAIN INCREASES. INLAND LOCATIONS WILL ALSO SEE
INCREASING MVFR CONDITIONS IN RAIN BETWEEN 16-18Z TODAY. THE MAIN
EXCEPTION WILL BE FOR THE CENTRAL AND SOUTHERN WILLAMETTE VALLEY
WHERE IFR AND LIFR FOG/LOW STRATUS WILL PERSIST THROUGH MUCH OF
TODAY...POSSIBLY LIFTING TO LOW END MVFR AFTER 21Z TODAY WHEN
SOUTHERLY WINDS PICK UP.

KPDX AND APPROACHES...VFR CONTINUES THROUGH AT LEAST 16Z THIS
MORNING BEFORE INCREASING RAIN DROPS CONDITIONS TO MVFR BY 18Z
THROUGH TONIGHT. LLWS POSSIBLE AT KPDX AND ERN APPROACHES THIS
AFTERNOON WITH E TO SE SURFACE AND 30-40 KT S-SW WIND AT FL 020
BASED ON MODEL SOUNDINGS. WEISHAAR/27

&&

.MARINE...SOUTHERLY WINDS WILL CONTINUE TO HOVER RIGHT NEAR SMALL
CRAFT ADVISORY CRITERIA WITH GUSTS NEAR 25 KT THROUGH THIS
MORNING. THE NEXT FRONTAL SYSTEM WILL BRING SOLID GALE FORCE WINDS
ACROSS ALL OF THE WATERS BY 18Z TODAY...WITH STRONGEST WINDS FROM
21Z FRI-03Z SAT OVER THE INNER COASTAL WATERS. 06Z MODELS HAVE
BACKED OFF A BIT ON WIND SPEEDS SO HAVE REPLACED THE STORM WATCH
WITH A GALE WARNING FOR THE WATERS 10 NM FROM THE SHORELINE. STILL
A FEW GUSTS NEAR 50 KT ARE POSSIBLE THIS AFTERNOON WITH A COASTAL
JET SITUATION. WIND SPEEDS SUBSIDE BY 06Z TONIGHT...AND WILL
REMAIN IN SMALL CRAFT ADVISORY CRITERIA THROUGH MUCH OF THE
WEEKEND.

SEAS AT 10 FT WILL CONTINUE EARLY TODAY...BEFORE QUICKLY BUILDING
BY NOON TODAY WITH THE STRONG GALE FORCE WIND CONDITIONS. COULD
GET CLOSE TO 20 FEET LATE FRI AFTERNOON THROUGH THE EVENING...BUT
WITH A LARGE WIND- WAVE COMPONENT. WAVE HEIGHTS DROP OFF TONIGHT
BEHIND THE COLD FRONT AND AS WIND SPEEDS WEAKEN. HOWEVER...SEAS
LOOK TO REMAIN ABOVE 10 FT THROUGH THIS WEEKEND. WEISHAAR/27

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...DENSE FOG ADVISORY UNTIL 9 AM PST THIS MORNING FOR CENTRAL
     WILLAMETTE VALLEY-SOUTH WILLAMETTE VALLEY.

     HIGH WIND WARNING FROM NOON PST TODAY THROUGH THIS EVENING FOR
     CENTRAL OREGON COAST-NORTH OREGON COAST.

WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 10 AM PST THIS MORNING FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     GALE WARNING FROM 10 AM THIS MORNING TO 10 PM PST THIS EVENING
     FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR
     OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 AM PST THIS
     MORNING FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
     FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 6 AM
     PST EARLY THIS MORNING...THEN AGAIN FROM NOON TODAY TO
     10 PM PST THIS EVENING.

&&

$$

INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND

THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.




000
FXUS66 KPQR 211127
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
323 AM PST FRI NOV 21 2014

CORRECTED WATCHES/WARNINGS/ADVISORIES SECTION.

.SYNOPSIS...MORE TYPICAL FALL WATHER IN STORE FOR SOUTHWEST
WASHINGTON AND NORTHWEST OREGON TODAY. COOLER AIR BEHIND THIS SYSTEM
WILL CAUSE THE SNOW LEVELS TO LOWER BELOW THE CASCADE PASSES EARLY
SATURDAY WHILE STRONG ONSHORE FLOW CONTINUES THROUGH THE WEEKEND. AS
A RESULT SNOW MAY BECOME HEAVY AT TIMES ALL THE WAY DOWN TO PASS
LEVELS THIS WEEKEND. ANOTHER SYSTEM IS LIKELY TO AFFECT THE REGION
EARLY NEXT WEEK...THEN PERHAPS SOME DRIER WEATHER BY MIDWEEK.

&&

.SHORT TERM...MORE MILD FALL WEATHER ON THE WAY. THE NEXT DEVELOPING
SYSTEM ARRIVES TODAY AS A STRONG FRONTAL SYSTEM TRAILING ALONG THE
NORTH PACIFIC 150 KT JETSTREAM. THE WARM FRONT PORTION WILL REACH
THE COAST THIS MORNING WITH THE TRAILING COLD FRONT ARRIVING THIS
AFTERNOON AND MOVING EAST OF THE CASCADES OVERNIGHT.
WIND...COASTAL WINDS LOOK MARGINAL FOR HIGH WINDS BUT BELIEVE THE
NORTH AND CENTRAL OREGON COAST HAVE THE BEST CHANCE FOR GUSTS TO 60
MPH AT THE BEACHES AND HEADLANDS.  PEAK WINDS ARE EXPECTED IN THE
MID TO LATE AFTERNOON. 850 MB AND 950 MB WINDS ALIGN ALONG THE COAST
JUST AS THE SURFACE GRADIENT PATTERN BECOMES FAVORABLE...A SHORT
WINDOW.   THE ECMWF DEEPENS THE LOW ON THE FRONT MORE THAN NAM AND
GFS...BUT PLACES IT CLOSER THE THE SOUTH WASHINGTON COAST.INLAND
VALLEYS WILL BECOME BREEZY LATE IN THE AFTERNOON AND EARLY EVENING.
GUSTS ARE EXPECTED TO REMAIN BELOW ANY ADVISORY OR WARNING CRITERIA.

COLUMBIA RIVER GORGE AND HOOD RIVER VALLEY...THE SHALLOW COLD AIR
MASS HAS NOT COOLED VERY MUCH OVERNIGHT.  MOST TEMPERATURES ARE
HOVERING A DEGREE OR TWO AROUND THE FREEZING MARK WITH ABOVE
FREEZING TEMPERATURES ALONG THE RIVER. TIMING OF THE PCPN AND
EXPECTED WARMING WILL LIKELY LIMIT FREEZING PRECIPITATION TO THE
UPPER HOOD RIVER VALLEY FOR THE MORNING HOURS.  ACCUMULATIONS AND
COVERAGE WILL NOT BE WIDESPREAD AS EARLIER THIS WEEK.

SNOW...SNOW LEVELS WILL INCREASE ABOVE ALL BUT THE HIGHEST PEAKS IN
THE AREA TODAY AS THE WARM FRONT APPROACHES. SNOW LEVELS WILL CRASH
TO AROUND 3000 TO 4000 FT SATURDAY MORNING. OROGRAPHICS BECOME
FAVORABLE IN THIS COLDER AIR MASS. 850 MB WINDS ARE WESTERLY 25 TO
45 KT SAT ALONG WITH ABUNDANT SHOWERS. SNOW WILL BE HEAVIER AT TIMES
AS IMPULSES MOVE THROUGH. IT APPEARS THE PERIOD OF HIGHER SNOWFALL
ACCUMULATION WILL BE SAT INTO EARLY SUN. THIS PERIOD MAY END UP
NEEDING A WINTER WEATHER ADVISORY.  CURRENT SPECIAL WEATHER
STATEMENT COVERS THIS UNTIL THEN.

RAIN AMOUNTS...A BATCH OF HEAVY RAIN TO PUSH INLAND DURING THE LATE
AFTERNOON AND EVENING...WITH 1.5 TO 2 INCHES OF RAIN LIKELY FOR THE
COAST...COAST RANGE AND CASCADES OVER ABOUT A 12 HR PERIOD ENDING
TONIGHT. THE INTERIOR LOWLANDS WILL BE CLOSER TO AN INCH. IT DOES NOT
APPEAR THAT RAINFALL TOTALS WILL BE ENOUGH TO CAUSE ANY FLOODING
CONCERNS.

CONVECTION...500 MB TEMPERATURES DROP TO AROUND -25 TO -30 C ON
SATURDAY. LIFTED INDEX LOWERS TO AROUND 0 TO -2. THERE IS ALSO A WEAK
VORT MAX THAT MOVES THROUGH DURING THE DAY TO ASSIST IN THE
INSTABILITY. SO HAVE ADDED A SLIGHT CHANCE OF THUNDERSTORMS OVER THE
WATERS AND INLAND TO THE COAST RANGE. THE INTERIOR LOWLAND MAY NEED
TO BE ADDED AS WELL...BUT THREAT APPEARS TOO LOW AT THIS TIME.

ALSO FOR THIS MORNING AREAS OF DENSE FOG DEVELOPED IN THE CENTRAL AND
SOUTH WILLAMETTE VALLEY OVERNIGHT BUT IS BEGINNING TO LIFT AS SO WILL
END THE DENSE FOG ADVISORY.  /26


.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY. THE MORE WESTERLY OR
ZONAL FLOW THAT SETS UP OVER THE WEEKEND DURING THE LATTER PART OF
THE SHORT TERM PERIOD BEGINS TO BUCKLE A BIT IN THE EARLY PART OF
THE LONG TERM PERIOD WITH SOME FLAT RIDGING DEVELOPING OVER THE
NORTHEAST PACIFIC. HAVE DECIDED TO CONTINUE TO STICK MORE WITH A
DIRTY RIDGE SCENARIO OF THE ECMWF VS THE HIGHER AMPLITUDE RIDGING OF
THE OPERATIONAL GFS MODEL. CONFIDENCE DECREASES THROUGHOUT THE LONG
TERM PERIOD AS MODEL VARIABILITY INCREASES...THOUGH THE TREND IS
TOWARD DRIER DURING THE MIDDLE TO LATTER PARTS OF NEXT WEEK. TOLLESON

&&

.AVIATION...EXPECT A VARIETY OF FLIGHT CONDITIONS TODAY AHEAD OF
AN APPROACHING FRONTAL SYSTEM. A MIX OF MVFR AND VFR WILL PERSIST
ALONG THE COAST...WITH MVFR CONDITIONS PREVAILING AFTER 14Z THIS
MORNING AS RAIN INCREASES. INLAND LOCATIONS WILL ALSO SEE
INCREASING MVFR CONDITIONS IN RAIN BETWEEN 16-18Z TODAY. THE MAIN
EXCEPTION WILL BE FOR THE CENTRAL AND SOUTHERN WILLAMETTE VALLEY
WHERE IFR AND LIFR FOG/LOW STRATUS WILL PERSIST THROUGH MUCH OF
TODAY...POSSIBLY LIFTING TO LOW END MVFR AFTER 21Z TODAY WHEN
SOUTHERLY WINDS PICK UP.

KPDX AND APPROACHES...VFR CONTINUES THROUGH AT LEAST 16Z THIS
MORNING BEFORE INCREASING RAIN DROPS CONDITIONS TO MVFR BY 18Z
THROUGH TONIGHT. LLWS POSSIBLE AT KPDX AND ERN APPROACHES THIS
AFTERNOON WITH E TO SE SURFACE AND 30-40 KT S-SW WIND AT FL 020
BASED ON MODEL SOUNDINGS. WEISHAAR/27

&&

.MARINE...SOUTHERLY WINDS WILL CONTINUE TO HOVER RIGHT NEAR SMALL
CRAFT ADVISORY CRITERIA WITH GUSTS NEAR 25 KT THROUGH THIS
MORNING. THE NEXT FRONTAL SYSTEM WILL BRING SOLID GALE FORCE WINDS
ACROSS ALL OF THE WATERS BY 18Z TODAY...WITH STRONGEST WINDS FROM
21Z FRI-03Z SAT OVER THE INNER COASTAL WATERS. 06Z MODELS HAVE
BACKED OFF A BIT ON WIND SPEEDS SO HAVE REPLACED THE STORM WATCH
WITH A GALE WARNING FOR THE WATERS 10 NM FROM THE SHORELINE. STILL
A FEW GUSTS NEAR 50 KT ARE POSSIBLE THIS AFTERNOON WITH A COASTAL
JET SITUATION. WIND SPEEDS SUBSIDE BY 06Z TONIGHT...AND WILL
REMAIN IN SMALL CRAFT ADVISORY CRITERIA THROUGH MUCH OF THE
WEEKEND.

SEAS AT 10 FT WILL CONTINUE EARLY TODAY...BEFORE QUICKLY BUILDING
BY NOON TODAY WITH THE STRONG GALE FORCE WIND CONDITIONS. COULD
GET CLOSE TO 20 FEET LATE FRI AFTERNOON THROUGH THE EVENING...BUT
WITH A LARGE WIND- WAVE COMPONENT. WAVE HEIGHTS DROP OFF TONIGHT
BEHIND THE COLD FRONT AND AS WIND SPEEDS WEAKEN. HOWEVER...SEAS
LOOK TO REMAIN ABOVE 10 FT THROUGH THIS WEEKEND. WEISHAAR/27

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...DENSE FOG ADVISORY UNTIL 9 AM PST THIS MORNING FOR CENTRAL
     WILLAMETTE VALLEY-SOUTH WILLAMETTE VALLEY.

     HIGH WIND WARNING FROM NOON PST TODAY THROUGH THIS EVENING FOR
     CENTRAL OREGON COAST-NORTH OREGON COAST.

WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 10 AM PST THIS MORNING FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     GALE WARNING FROM 10 AM THIS MORNING TO 10 PM PST THIS EVENING
     FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR
     OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 AM PST THIS
     MORNING FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
     FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 6 AM
     PST EARLY THIS MORNING...THEN AGAIN FROM NOON TODAY TO
     10 PM PST THIS EVENING.

&&

$$

INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND

THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.



000
FXUS66 KPQR 211109
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
303 AM PST FRI NOV 21 2014

.SYNOPSIS...MORE TYPICAL FALL WATHER IN STORE FOR SOUTHWEST
WASHINGTON AND NORTHWEST OREGON TODAY. COOLER AIR BEHIND THIS SYSTEM
WILL CAUSE THE SNOW LEVELS TO LOWER BELOW THE CASCADE PASSES EARLY
SATURDAY WHILE STRONG ONSHORE FLOW CONTINUES THROUGH THE WEEKEND. AS
A RESULT SNOW MAY BECOME HEAVY AT TIMES ALL THE WAY DOWN TO PASS
LEVELS THIS WEEKEND. ANOTHER SYSTEM IS LIKELY TO AFFECT THE REGION
EARLY NEXT WEEK...THEN PERHAPS SOME DRIER WEATHER BY MIDWEEK.

&&

.SHORT TERM...MORE MILD FALL WEATHER ON THE WAY. THE NEXT DEVELOPING
SYSTEM ARRIVES TODAY AS A STRONG FRONTAL SYSTEM TRAILING ALONG THE
NORTH PACIFIC 150 KT JETSTREAM. THE WARM FRONT PORTION WILL REACH
THE COAST THIS MORNING WITH THE TRAILING COLD FRONT ARRIVING THIS
AFTERNOON AND MOVING EAST OF THE CASCADES OVERNIGHT.
WIND...COASTAL WINDS LOOK MARGINAL FOR HIGH WINDS BUT BELIEVE THE
NORTH AND CENTRAL OREGON COAST HAVE THE BEST CHANCE FOR GUSTS TO 60
MPH AT THE BEACHES AND HEADLANDS.  PEAK WINDS ARE EXPECTED IN THE
MID TO LATE AFTERNOON. 850 MB AND 950 MB WINDS ALIGN ALONG THE COAST
JUST AS THE SURFACE GRADIENT PATTERN BECOMES FAVORABLE...A SHORT
WINDOW.   THE ECMWF DEEPENS THE LOW ON THE FRONT MORE THAN NAM AND
GFS...BUT PLACES IT CLOSER THE THE SOUTH WASHINGTON COAST.INLAND
VALLEYS WILL BECOME BREEZY LATE IN THE AFTERNOON AND EARLY EVENING.
GUSTS ARE EXPECTED TO REMAIN BELOW ANY ADVISORY OR WARNING CRITERIA.

COLUMBIA RIVER GORGE AND HOOD RIVER VALLEY...THE SHALLOW COLD AIR
MASS HAS NOT COOLED VERY MUCH OVERNIGHT.  MOST TEMPERATURES ARE
HOVERING A DEGREE OR TWO AROUND THE FREEZING MARK WITH ABOVE
FREEZING TEMPERATURES ALONG THE RIVER. TIMING OF THE PCPN AND
EXPECTED WARMING WILL LIKELY LIMIT FREEZING PRECIPITATION TO THE
UPPER HOOD RIVER VALLEY FOR THE MORNING HOURS.  ACCUMULATIONS AND
COVERAGE WILL NOT BE WIDESPREAD AS EARLIER THIS WEEK.

SNOW...SNOW LEVELS WILL INCREASE ABOVE ALL BUT THE HIGHEST PEAKS IN
THE AREA TODAY AS THE WARM FRONT APPROACHES. SNOW LEVELS WILL CRASH
TO AROUND 3000 TO 4000 FT SATURDAY MORNING. OROGRAPHICS BECOME
FAVORABLE IN THIS COLDER AIR MASS. 850 MB WINDS ARE WESTERLY 25 TO
45 KT SAT ALONG WITH ABUNDANT SHOWERS. SNOW WILL BE HEAVIER AT TIMES
AS IMPULSES MOVE THROUGH. IT APPEARS THE PERIOD OF HIGHER SNOWFALL
ACCUMULATION WILL BE SAT INTO EARLY SUN. THIS PERIOD MAY END UP
NEEDING A WINTER WEATHER ADVISORY.  CURRENT SPECIAL WEATHER
STATEMENT COVERS THIS UNTIL THEN.

RAIN AMOUNTS...A BATCH OF HEAVY RAIN TO PUSH INLAND DURING THE LATE
AFTERNOON AND EVENING...WITH 1.5 TO 2 INCHES OF RAIN LIKELY FOR THE
COAST...COAST RANGE AND CASCADES OVER ABOUT A 12 HR PERIOD ENDING
TONIGHT. THE INTERIOR LOWLANDS WILL BE CLOSER TO AN INCH. IT DOES NOT
APPEAR THAT RAINFALL TOTALS WILL BE ENOUGH TO CAUSE ANY FLOODING
CONCERNS.

CONVECTION...500 MB TEMPERATURES DROP TO AROUND -25 TO -30 C ON
SATURDAY. LIFTED INDEX LOWERS TO AROUND 0 TO -2. THERE IS ALSO A WEAK
VORT MAX THAT MOVES THROUGH DURING THE DAY TO ASSIST IN THE
INSTABILITY. SO HAVE ADDED A SLIGHT CHANCE OF THUNDERSTORMS OVER THE
WATERS AND INLAND TO THE COAST RANGE. THE INTERIOR LOWLAND MAY NEED
TO BE ADDED AS WELL...BUT THREAT APPEARS TOO LOW AT THIS TIME.

ALSO FOR THIS MORNING AREAS OF DENSE FOG DEVELOPED IN THE CENTRAL AND
SOUTH WILLAMETTE VALLEY OVERNIGHT BUT IS BEGINNING TO LIFT AS SO WILL
END THE DENSE FOG ADVISORY.  /26


.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY. THE MORE WESTERLY OR
ZONAL FLOW THAT SETS UP OVER THE WEEKEND DURING THE LATTER PART OF
THE SHORT TERM PERIOD BEGINS TO BUCKLE A BIT IN THE EARLY PART OF
THE LONG TERM PERIOD WITH SOME FLAT RIDGING DEVELOPING OVER THE
NORTHEAST PACIFIC. HAVE DECIDED TO CONTINUE TO STICK MORE WITH A
DIRTY RIDGE SCENARIO OF THE ECMWF VS THE HIGHER AMPLITUDE RIDGING OF
THE OPERATIONAL GFS MODEL. CONFIDENCE DECREASES THROUGHOUT THE LONG
TERM PERIOD AS MODEL VARIABILITY INCREASES...THOUGH THE TREND IS
TOWARD DRIER DURING THE MIDDLE TO LATTER PARTS OF NEXT WEEK. TOLLESON

&&

.AVIATION...EXPECT A VARIETY OF FLIGHT CONDITIONS TODAY AHEAD OF
AN APPROACHING FRONTAL SYSTEM. A MIX OF MVFR AND VFR WILL PERSIST
ALONG THE COAST...WITH MVFR CONDITIONS PREVAILING AFTER 14Z THIS
MORNING AS RAIN INCREASES. INLAND LOCATIONS WILL ALSO SEE
INCREASING MVFR CONDITIONS IN RAIN BETWEEN 16-18Z TODAY. THE MAIN
EXCEPTION WILL BE FOR THE CENTRAL AND SOUTHERN WILLAMETTE VALLEY
WHERE IFR AND LIFR FOG/LOW STRATUS WILL PERSIST THROUGH MUCH OF
TODAY...POSSIBLY LIFTING TO LOW END MVFR AFTER 21Z TODAY WHEN
SOUTHERLY WINDS PICK UP.

KPDX AND APPROACHES...VFR CONTINUES THROUGH AT LEAST 16Z THIS
MORNING BEFORE INCREASING RAIN DROPS CONDITIONS TO MVFR BY 18Z
THROUGH TONIGHT. LLWS POSSIBLE AT KPDX AND ERN APPROACHES THIS
AFTERNOON WITH E TO SE SURFACE AND 30-40 KT S-SW WIND AT FL 020
BASED ON MODEL SOUNDINGS. WEISHAAR/27

&&

.MARINE...SOUTHERLY WINDS WILL CONTINUE TO HOVER RIGHT NEAR SMALL
CRAFT ADVISORY CRITERIA WITH GUSTS NEAR 25 KT THROUGH THIS
MORNING. THE NEXT FRONTAL SYSTEM WILL BRING SOLID GALE FORCE WINDS
ACROSS ALL OF THE WATERS BY 18Z TODAY...WITH STRONGEST WINDS FROM
21Z FRI-03Z SAT OVER THE INNER COASTAL WATERS. 06Z MODELS HAVE
BACKED OFF A BIT ON WIND SPEEDS SO HAVE REPLACED THE STORM WATCH
WITH A GALE WARNING FOR THE WATERS 10 NM FROM THE SHORELINE. STILL
A FEW GUSTS NEAR 50 KT ARE POSSIBLE THIS AFTERNOON WITH A COASTAL
JET SITUATION. WIND SPEEDS SUBSIDE BY 06Z TONIGHT...AND WILL
REMAIN IN SMALL CRAFT ADVISORY CRITERIA THROUGH MUCH OF THE
WEEKEND.

SEAS AT 10 FT WILL CONTINUE EARLY TODAY...BEFORE QUICKLY BUILDING
BY NOON TODAY WITH THE STRONG GALE FORCE WIND CONDITIONS. COULD
GET CLOSE TO 20 FEET LATE FRI AFTERNOON THROUGH THE EVENING...BUT
WITH A LARGE WIND- WAVE COMPONENT. WAVE HEIGHTS DROP OFF TONIGHT
BEHIND THE COLD FRONT AND AS WIND SPEEDS WEAKEN. HOWEVER...SEAS
LOOK TO REMAIN ABOVE 10 FT THROUGH THIS WEEKEND. WEISHAAR/27

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...DENSE FOG ADVISORY UNTIL 9 AM PST THIS MORNING FOR CENTRAL
     WILLAMETTE VALLEY-SOUTH WILLAMETTE VALLEY.

     HIGH WIND WATCH FROM NOON PST TODAY THROUGH THIS EVENING FOR
     CENTRAL OREGON COAST-NORTH OREGON COAST.

WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 10 AM PST THIS MORNING FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     GALE WARNING FROM 10 AM THIS MORNING TO 10 PM PST THIS EVENING
     FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR
     OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 AM PST THIS
     MORNING FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
     FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 6 AM
     PST EARLY THIS MORNING...THEN AGAIN FROM NOON TODAY TO
     10 PM PST THIS EVENING.

&&

$$

INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND

THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.



000
FXUS66 KPQR 211109
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
303 AM PST FRI NOV 21 2014

.SYNOPSIS...MORE TYPICAL FALL WATHER IN STORE FOR SOUTHWEST
WASHINGTON AND NORTHWEST OREGON TODAY. COOLER AIR BEHIND THIS SYSTEM
WILL CAUSE THE SNOW LEVELS TO LOWER BELOW THE CASCADE PASSES EARLY
SATURDAY WHILE STRONG ONSHORE FLOW CONTINUES THROUGH THE WEEKEND. AS
A RESULT SNOW MAY BECOME HEAVY AT TIMES ALL THE WAY DOWN TO PASS
LEVELS THIS WEEKEND. ANOTHER SYSTEM IS LIKELY TO AFFECT THE REGION
EARLY NEXT WEEK...THEN PERHAPS SOME DRIER WEATHER BY MIDWEEK.

&&

.SHORT TERM...MORE MILD FALL WEATHER ON THE WAY. THE NEXT DEVELOPING
SYSTEM ARRIVES TODAY AS A STRONG FRONTAL SYSTEM TRAILING ALONG THE
NORTH PACIFIC 150 KT JETSTREAM. THE WARM FRONT PORTION WILL REACH
THE COAST THIS MORNING WITH THE TRAILING COLD FRONT ARRIVING THIS
AFTERNOON AND MOVING EAST OF THE CASCADES OVERNIGHT.
WIND...COASTAL WINDS LOOK MARGINAL FOR HIGH WINDS BUT BELIEVE THE
NORTH AND CENTRAL OREGON COAST HAVE THE BEST CHANCE FOR GUSTS TO 60
MPH AT THE BEACHES AND HEADLANDS.  PEAK WINDS ARE EXPECTED IN THE
MID TO LATE AFTERNOON. 850 MB AND 950 MB WINDS ALIGN ALONG THE COAST
JUST AS THE SURFACE GRADIENT PATTERN BECOMES FAVORABLE...A SHORT
WINDOW.   THE ECMWF DEEPENS THE LOW ON THE FRONT MORE THAN NAM AND
GFS...BUT PLACES IT CLOSER THE THE SOUTH WASHINGTON COAST.INLAND
VALLEYS WILL BECOME BREEZY LATE IN THE AFTERNOON AND EARLY EVENING.
GUSTS ARE EXPECTED TO REMAIN BELOW ANY ADVISORY OR WARNING CRITERIA.

COLUMBIA RIVER GORGE AND HOOD RIVER VALLEY...THE SHALLOW COLD AIR
MASS HAS NOT COOLED VERY MUCH OVERNIGHT.  MOST TEMPERATURES ARE
HOVERING A DEGREE OR TWO AROUND THE FREEZING MARK WITH ABOVE
FREEZING TEMPERATURES ALONG THE RIVER. TIMING OF THE PCPN AND
EXPECTED WARMING WILL LIKELY LIMIT FREEZING PRECIPITATION TO THE
UPPER HOOD RIVER VALLEY FOR THE MORNING HOURS.  ACCUMULATIONS AND
COVERAGE WILL NOT BE WIDESPREAD AS EARLIER THIS WEEK.

SNOW...SNOW LEVELS WILL INCREASE ABOVE ALL BUT THE HIGHEST PEAKS IN
THE AREA TODAY AS THE WARM FRONT APPROACHES. SNOW LEVELS WILL CRASH
TO AROUND 3000 TO 4000 FT SATURDAY MORNING. OROGRAPHICS BECOME
FAVORABLE IN THIS COLDER AIR MASS. 850 MB WINDS ARE WESTERLY 25 TO
45 KT SAT ALONG WITH ABUNDANT SHOWERS. SNOW WILL BE HEAVIER AT TIMES
AS IMPULSES MOVE THROUGH. IT APPEARS THE PERIOD OF HIGHER SNOWFALL
ACCUMULATION WILL BE SAT INTO EARLY SUN. THIS PERIOD MAY END UP
NEEDING A WINTER WEATHER ADVISORY.  CURRENT SPECIAL WEATHER
STATEMENT COVERS THIS UNTIL THEN.

RAIN AMOUNTS...A BATCH OF HEAVY RAIN TO PUSH INLAND DURING THE LATE
AFTERNOON AND EVENING...WITH 1.5 TO 2 INCHES OF RAIN LIKELY FOR THE
COAST...COAST RANGE AND CASCADES OVER ABOUT A 12 HR PERIOD ENDING
TONIGHT. THE INTERIOR LOWLANDS WILL BE CLOSER TO AN INCH. IT DOES NOT
APPEAR THAT RAINFALL TOTALS WILL BE ENOUGH TO CAUSE ANY FLOODING
CONCERNS.

CONVECTION...500 MB TEMPERATURES DROP TO AROUND -25 TO -30 C ON
SATURDAY. LIFTED INDEX LOWERS TO AROUND 0 TO -2. THERE IS ALSO A WEAK
VORT MAX THAT MOVES THROUGH DURING THE DAY TO ASSIST IN THE
INSTABILITY. SO HAVE ADDED A SLIGHT CHANCE OF THUNDERSTORMS OVER THE
WATERS AND INLAND TO THE COAST RANGE. THE INTERIOR LOWLAND MAY NEED
TO BE ADDED AS WELL...BUT THREAT APPEARS TOO LOW AT THIS TIME.

ALSO FOR THIS MORNING AREAS OF DENSE FOG DEVELOPED IN THE CENTRAL AND
SOUTH WILLAMETTE VALLEY OVERNIGHT BUT IS BEGINNING TO LIFT AS SO WILL
END THE DENSE FOG ADVISORY.  /26


.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY. THE MORE WESTERLY OR
ZONAL FLOW THAT SETS UP OVER THE WEEKEND DURING THE LATTER PART OF
THE SHORT TERM PERIOD BEGINS TO BUCKLE A BIT IN THE EARLY PART OF
THE LONG TERM PERIOD WITH SOME FLAT RIDGING DEVELOPING OVER THE
NORTHEAST PACIFIC. HAVE DECIDED TO CONTINUE TO STICK MORE WITH A
DIRTY RIDGE SCENARIO OF THE ECMWF VS THE HIGHER AMPLITUDE RIDGING OF
THE OPERATIONAL GFS MODEL. CONFIDENCE DECREASES THROUGHOUT THE LONG
TERM PERIOD AS MODEL VARIABILITY INCREASES...THOUGH THE TREND IS
TOWARD DRIER DURING THE MIDDLE TO LATTER PARTS OF NEXT WEEK. TOLLESON

&&

.AVIATION...EXPECT A VARIETY OF FLIGHT CONDITIONS TODAY AHEAD OF
AN APPROACHING FRONTAL SYSTEM. A MIX OF MVFR AND VFR WILL PERSIST
ALONG THE COAST...WITH MVFR CONDITIONS PREVAILING AFTER 14Z THIS
MORNING AS RAIN INCREASES. INLAND LOCATIONS WILL ALSO SEE
INCREASING MVFR CONDITIONS IN RAIN BETWEEN 16-18Z TODAY. THE MAIN
EXCEPTION WILL BE FOR THE CENTRAL AND SOUTHERN WILLAMETTE VALLEY
WHERE IFR AND LIFR FOG/LOW STRATUS WILL PERSIST THROUGH MUCH OF
TODAY...POSSIBLY LIFTING TO LOW END MVFR AFTER 21Z TODAY WHEN
SOUTHERLY WINDS PICK UP.

KPDX AND APPROACHES...VFR CONTINUES THROUGH AT LEAST 16Z THIS
MORNING BEFORE INCREASING RAIN DROPS CONDITIONS TO MVFR BY 18Z
THROUGH TONIGHT. LLWS POSSIBLE AT KPDX AND ERN APPROACHES THIS
AFTERNOON WITH E TO SE SURFACE AND 30-40 KT S-SW WIND AT FL 020
BASED ON MODEL SOUNDINGS. WEISHAAR/27

&&

.MARINE...SOUTHERLY WINDS WILL CONTINUE TO HOVER RIGHT NEAR SMALL
CRAFT ADVISORY CRITERIA WITH GUSTS NEAR 25 KT THROUGH THIS
MORNING. THE NEXT FRONTAL SYSTEM WILL BRING SOLID GALE FORCE WINDS
ACROSS ALL OF THE WATERS BY 18Z TODAY...WITH STRONGEST WINDS FROM
21Z FRI-03Z SAT OVER THE INNER COASTAL WATERS. 06Z MODELS HAVE
BACKED OFF A BIT ON WIND SPEEDS SO HAVE REPLACED THE STORM WATCH
WITH A GALE WARNING FOR THE WATERS 10 NM FROM THE SHORELINE. STILL
A FEW GUSTS NEAR 50 KT ARE POSSIBLE THIS AFTERNOON WITH A COASTAL
JET SITUATION. WIND SPEEDS SUBSIDE BY 06Z TONIGHT...AND WILL
REMAIN IN SMALL CRAFT ADVISORY CRITERIA THROUGH MUCH OF THE
WEEKEND.

SEAS AT 10 FT WILL CONTINUE EARLY TODAY...BEFORE QUICKLY BUILDING
BY NOON TODAY WITH THE STRONG GALE FORCE WIND CONDITIONS. COULD
GET CLOSE TO 20 FEET LATE FRI AFTERNOON THROUGH THE EVENING...BUT
WITH A LARGE WIND- WAVE COMPONENT. WAVE HEIGHTS DROP OFF TONIGHT
BEHIND THE COLD FRONT AND AS WIND SPEEDS WEAKEN. HOWEVER...SEAS
LOOK TO REMAIN ABOVE 10 FT THROUGH THIS WEEKEND. WEISHAAR/27

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...DENSE FOG ADVISORY UNTIL 9 AM PST THIS MORNING FOR CENTRAL
     WILLAMETTE VALLEY-SOUTH WILLAMETTE VALLEY.

     HIGH WIND WATCH FROM NOON PST TODAY THROUGH THIS EVENING FOR
     CENTRAL OREGON COAST-NORTH OREGON COAST.

WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 10 AM PST THIS MORNING FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     GALE WARNING FROM 10 AM THIS MORNING TO 10 PM PST THIS EVENING
     FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR
     OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 AM PST THIS
     MORNING FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
     FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 6 AM
     PST EARLY THIS MORNING...THEN AGAIN FROM NOON TODAY TO
     10 PM PST THIS EVENING.

&&

$$

INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND

THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.



000
FXUS66 KPQR 211109
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
303 AM PST FRI NOV 21 2014

.SYNOPSIS...MORE TYPICAL FALL WATHER IN STORE FOR SOUTHWEST
WASHINGTON AND NORTHWEST OREGON TODAY. COOLER AIR BEHIND THIS SYSTEM
WILL CAUSE THE SNOW LEVELS TO LOWER BELOW THE CASCADE PASSES EARLY
SATURDAY WHILE STRONG ONSHORE FLOW CONTINUES THROUGH THE WEEKEND. AS
A RESULT SNOW MAY BECOME HEAVY AT TIMES ALL THE WAY DOWN TO PASS
LEVELS THIS WEEKEND. ANOTHER SYSTEM IS LIKELY TO AFFECT THE REGION
EARLY NEXT WEEK...THEN PERHAPS SOME DRIER WEATHER BY MIDWEEK.

&&

.SHORT TERM...MORE MILD FALL WEATHER ON THE WAY. THE NEXT DEVELOPING
SYSTEM ARRIVES TODAY AS A STRONG FRONTAL SYSTEM TRAILING ALONG THE
NORTH PACIFIC 150 KT JETSTREAM. THE WARM FRONT PORTION WILL REACH
THE COAST THIS MORNING WITH THE TRAILING COLD FRONT ARRIVING THIS
AFTERNOON AND MOVING EAST OF THE CASCADES OVERNIGHT.
WIND...COASTAL WINDS LOOK MARGINAL FOR HIGH WINDS BUT BELIEVE THE
NORTH AND CENTRAL OREGON COAST HAVE THE BEST CHANCE FOR GUSTS TO 60
MPH AT THE BEACHES AND HEADLANDS.  PEAK WINDS ARE EXPECTED IN THE
MID TO LATE AFTERNOON. 850 MB AND 950 MB WINDS ALIGN ALONG THE COAST
JUST AS THE SURFACE GRADIENT PATTERN BECOMES FAVORABLE...A SHORT
WINDOW.   THE ECMWF DEEPENS THE LOW ON THE FRONT MORE THAN NAM AND
GFS...BUT PLACES IT CLOSER THE THE SOUTH WASHINGTON COAST.INLAND
VALLEYS WILL BECOME BREEZY LATE IN THE AFTERNOON AND EARLY EVENING.
GUSTS ARE EXPECTED TO REMAIN BELOW ANY ADVISORY OR WARNING CRITERIA.

COLUMBIA RIVER GORGE AND HOOD RIVER VALLEY...THE SHALLOW COLD AIR
MASS HAS NOT COOLED VERY MUCH OVERNIGHT.  MOST TEMPERATURES ARE
HOVERING A DEGREE OR TWO AROUND THE FREEZING MARK WITH ABOVE
FREEZING TEMPERATURES ALONG THE RIVER. TIMING OF THE PCPN AND
EXPECTED WARMING WILL LIKELY LIMIT FREEZING PRECIPITATION TO THE
UPPER HOOD RIVER VALLEY FOR THE MORNING HOURS.  ACCUMULATIONS AND
COVERAGE WILL NOT BE WIDESPREAD AS EARLIER THIS WEEK.

SNOW...SNOW LEVELS WILL INCREASE ABOVE ALL BUT THE HIGHEST PEAKS IN
THE AREA TODAY AS THE WARM FRONT APPROACHES. SNOW LEVELS WILL CRASH
TO AROUND 3000 TO 4000 FT SATURDAY MORNING. OROGRAPHICS BECOME
FAVORABLE IN THIS COLDER AIR MASS. 850 MB WINDS ARE WESTERLY 25 TO
45 KT SAT ALONG WITH ABUNDANT SHOWERS. SNOW WILL BE HEAVIER AT TIMES
AS IMPULSES MOVE THROUGH. IT APPEARS THE PERIOD OF HIGHER SNOWFALL
ACCUMULATION WILL BE SAT INTO EARLY SUN. THIS PERIOD MAY END UP
NEEDING A WINTER WEATHER ADVISORY.  CURRENT SPECIAL WEATHER
STATEMENT COVERS THIS UNTIL THEN.

RAIN AMOUNTS...A BATCH OF HEAVY RAIN TO PUSH INLAND DURING THE LATE
AFTERNOON AND EVENING...WITH 1.5 TO 2 INCHES OF RAIN LIKELY FOR THE
COAST...COAST RANGE AND CASCADES OVER ABOUT A 12 HR PERIOD ENDING
TONIGHT. THE INTERIOR LOWLANDS WILL BE CLOSER TO AN INCH. IT DOES NOT
APPEAR THAT RAINFALL TOTALS WILL BE ENOUGH TO CAUSE ANY FLOODING
CONCERNS.

CONVECTION...500 MB TEMPERATURES DROP TO AROUND -25 TO -30 C ON
SATURDAY. LIFTED INDEX LOWERS TO AROUND 0 TO -2. THERE IS ALSO A WEAK
VORT MAX THAT MOVES THROUGH DURING THE DAY TO ASSIST IN THE
INSTABILITY. SO HAVE ADDED A SLIGHT CHANCE OF THUNDERSTORMS OVER THE
WATERS AND INLAND TO THE COAST RANGE. THE INTERIOR LOWLAND MAY NEED
TO BE ADDED AS WELL...BUT THREAT APPEARS TOO LOW AT THIS TIME.

ALSO FOR THIS MORNING AREAS OF DENSE FOG DEVELOPED IN THE CENTRAL AND
SOUTH WILLAMETTE VALLEY OVERNIGHT BUT IS BEGINNING TO LIFT AS SO WILL
END THE DENSE FOG ADVISORY.  /26


.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY. THE MORE WESTERLY OR
ZONAL FLOW THAT SETS UP OVER THE WEEKEND DURING THE LATTER PART OF
THE SHORT TERM PERIOD BEGINS TO BUCKLE A BIT IN THE EARLY PART OF
THE LONG TERM PERIOD WITH SOME FLAT RIDGING DEVELOPING OVER THE
NORTHEAST PACIFIC. HAVE DECIDED TO CONTINUE TO STICK MORE WITH A
DIRTY RIDGE SCENARIO OF THE ECMWF VS THE HIGHER AMPLITUDE RIDGING OF
THE OPERATIONAL GFS MODEL. CONFIDENCE DECREASES THROUGHOUT THE LONG
TERM PERIOD AS MODEL VARIABILITY INCREASES...THOUGH THE TREND IS
TOWARD DRIER DURING THE MIDDLE TO LATTER PARTS OF NEXT WEEK. TOLLESON

&&

.AVIATION...EXPECT A VARIETY OF FLIGHT CONDITIONS TODAY AHEAD OF
AN APPROACHING FRONTAL SYSTEM. A MIX OF MVFR AND VFR WILL PERSIST
ALONG THE COAST...WITH MVFR CONDITIONS PREVAILING AFTER 14Z THIS
MORNING AS RAIN INCREASES. INLAND LOCATIONS WILL ALSO SEE
INCREASING MVFR CONDITIONS IN RAIN BETWEEN 16-18Z TODAY. THE MAIN
EXCEPTION WILL BE FOR THE CENTRAL AND SOUTHERN WILLAMETTE VALLEY
WHERE IFR AND LIFR FOG/LOW STRATUS WILL PERSIST THROUGH MUCH OF
TODAY...POSSIBLY LIFTING TO LOW END MVFR AFTER 21Z TODAY WHEN
SOUTHERLY WINDS PICK UP.

KPDX AND APPROACHES...VFR CONTINUES THROUGH AT LEAST 16Z THIS
MORNING BEFORE INCREASING RAIN DROPS CONDITIONS TO MVFR BY 18Z
THROUGH TONIGHT. LLWS POSSIBLE AT KPDX AND ERN APPROACHES THIS
AFTERNOON WITH E TO SE SURFACE AND 30-40 KT S-SW WIND AT FL 020
BASED ON MODEL SOUNDINGS. WEISHAAR/27

&&

.MARINE...SOUTHERLY WINDS WILL CONTINUE TO HOVER RIGHT NEAR SMALL
CRAFT ADVISORY CRITERIA WITH GUSTS NEAR 25 KT THROUGH THIS
MORNING. THE NEXT FRONTAL SYSTEM WILL BRING SOLID GALE FORCE WINDS
ACROSS ALL OF THE WATERS BY 18Z TODAY...WITH STRONGEST WINDS FROM
21Z FRI-03Z SAT OVER THE INNER COASTAL WATERS. 06Z MODELS HAVE
BACKED OFF A BIT ON WIND SPEEDS SO HAVE REPLACED THE STORM WATCH
WITH A GALE WARNING FOR THE WATERS 10 NM FROM THE SHORELINE. STILL
A FEW GUSTS NEAR 50 KT ARE POSSIBLE THIS AFTERNOON WITH A COASTAL
JET SITUATION. WIND SPEEDS SUBSIDE BY 06Z TONIGHT...AND WILL
REMAIN IN SMALL CRAFT ADVISORY CRITERIA THROUGH MUCH OF THE
WEEKEND.

SEAS AT 10 FT WILL CONTINUE EARLY TODAY...BEFORE QUICKLY BUILDING
BY NOON TODAY WITH THE STRONG GALE FORCE WIND CONDITIONS. COULD
GET CLOSE TO 20 FEET LATE FRI AFTERNOON THROUGH THE EVENING...BUT
WITH A LARGE WIND- WAVE COMPONENT. WAVE HEIGHTS DROP OFF TONIGHT
BEHIND THE COLD FRONT AND AS WIND SPEEDS WEAKEN. HOWEVER...SEAS
LOOK TO REMAIN ABOVE 10 FT THROUGH THIS WEEKEND. WEISHAAR/27

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...DENSE FOG ADVISORY UNTIL 9 AM PST THIS MORNING FOR CENTRAL
     WILLAMETTE VALLEY-SOUTH WILLAMETTE VALLEY.

     HIGH WIND WATCH FROM NOON PST TODAY THROUGH THIS EVENING FOR
     CENTRAL OREGON COAST-NORTH OREGON COAST.

WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 10 AM PST THIS MORNING FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     GALE WARNING FROM 10 AM THIS MORNING TO 10 PM PST THIS EVENING
     FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR
     OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 AM PST THIS
     MORNING FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
     FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 6 AM
     PST EARLY THIS MORNING...THEN AGAIN FROM NOON TODAY TO
     10 PM PST THIS EVENING.

&&

$$

INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND

THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.




000
FXUS66 KOTX 210708
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
1108 PM PST THU NOV 20 2014

.SYNOPSIS...
A relatively quiet and cool overnight period with a few snow
showers over the north will give way to a sharp deterioration in
the weather on Friday as a strong and moist Pacific storm brings
valley rain and mountain snow Friday night followed by very windy
conditions on Saturday. An active and periodically wet weather
regime will continue through the next week.



&&

.DISCUSSION...
Second update to add winter weather advisory for the Wenatchee
Zone. At this time, looks like there is a potential for 1-2
inches near Wenatchee and two to four inches in northern areas of
the zone with locally heavier amounts in the higher benches.
Another reason for the advisory was the threat for a mixed bag of
precipitation as the warmer air arrives. Could see periods of
freezing rain or sleet and overall, travel conditions could be
very slick even if snow amounts are underdone. /sb


&&

.AVIATION...
06Z TAFS: MVFR Ceilings and vis will be common over the region
through tomorrow morning as a moist boundary layer and light
winds exists under a strong low level inversion...with a mix of
MVFR and IFR conditions. Increasing lift into the moist boundary
layer will also bring a small chance for spotty freezing drizzle.
A moist Pacific storm system will spread thickening clouds over
the region on Friday with -SN/-RA to develop aft 18z in KEAT and
aft 00z at KGEG. Pcpn will vary btwn -SN and -FZRA at KEAT and
could be moderate at times. Warmer conditions will bring mostly
rain to KMWH/KGEG-KCOE/KPUW/KLWS. Breezy southerly winds and
lighter pcpn will keep KPUW/KLWS VFR conditions. /sb




&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        28  37  36  43  30  40 /  20  30 100  30  20  60
Coeur d`Alene  30  39  36  42  31  39 /  30  50 100  50  30  70
Pullman        33  41  36  43  34  42 /  10  10 100  70  40  60
Lewiston       35  44  40  48  36  47 /  10  10 100  70  30  50
Colville       27  37  34  44  20  38 /  30  70 100  50  10  60
Sandpoint      29  37  35  41  29  37 /  50  70 100  70  30  70
Kellogg        31  37  36  39  32  36 /  40  50 100  80  60  80
Moses Lake     26  36  35  48  30  46 /  10  50 100  10  10  30
Wenatchee      30  35  35  47  34  45 /  10  80 100  10  10  40
Omak           30  35  33  45  27  39 /  10  90 100  20  10  40

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Air Stagnation Advisory until Noon PST Friday for Central
     Panhandle Mountains-Coeur d`Alene Area-Idaho Palouse-
     Northern Panhandle.

     Winter Storm Warning from Noon Friday to 6 PM PST Saturday for
     Northern Panhandle.

     Winter Storm Warning from Noon Friday to 6 AM PST Sunday for
     Central Panhandle Mountains.

WA...Air Stagnation Advisory until Noon PST Friday for East Slopes
     Northern Cascades-Lower Garfield and Asotin Counties-Moses
     Lake Area-Northeast Mountains-Okanogan Highlands-Spokane
     Area-Upper Columbia Basin-Washington Palouse-Waterville
     Plateau-Wenatchee Area.

     Winter Storm Warning from Noon Friday to 6 AM PST Saturday for
     East Slopes Northern Cascades-Okanogan Highlands-Okanogan
     Valley-Waterville Plateau.

     Winter Storm Warning from Noon Friday to 6 PM PST Saturday for
     Northeast Mountains.

     Winter Weather Advisory from Noon Friday to 6 AM PST Saturday
     for Wenatchee Area.

&&

$$




000
FXUS66 KOTX 210457
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
857 PM PST THU NOV 20 2014

.SYNOPSIS...
A relatively quiet and cool overnight period with a few snow
showers over the north will give way to a sharp deterioration in
the weather on Friday as a strong and moist Pacific storm brings
valley rain and mountain snow Friday night followed by very windy
conditions on Saturday. An active and periodically wet weather
regime will continue through the next week.


&&

.DISCUSSION...

...REFREEZING ROADS AND POTENTIAL FOR additional FREEZING DRIZZLE
TO CREATE SLICK TRAVEL OVERNIGHT...

Evening update: A complex and active winter weather pattern will
be the focus for the next 36 hours. Here are the changes we have
made or will be focusing on tonight.

For tonight, we have added patchy freezing drizzle to majority of
the Columbia Basin, West Plains, and northern Palouse. Light
echoes continue to blossom across the region as warm air
advection/isentropic ascent strengthens ahead of a
weak...splitting trof currently moving across the Cascades.
Further investigation into soundings suggest the moisture will
generally remain below the dendritic layer (ie. drizzle) ahead
and behind the weak wave but could briefly saturate this layer as
it passes through. While confidence is generally low, this would
indicate drizzle falling out of the stratus (low clouds)...briefly
becoming snow, sleet, or rain/freezing rain, then transitioning
back to drizzle. This is where surface temperatures become very
important. Most locations remain below freezing at this hour. The
exception is the Palouse, L-C Valley, and Camas Prairie which are
in the upper 30s to lower 40s and carrying dewpoints in the mid
30s suggesting temperatures will not fall much tonight away from
the mid 30s. On top of that, moisture from earlier precipitation
will likely refreeze to surfaces. All things considered, there is
a good chance that motorists will encounter icy travel across much
of the region.

For Friday, we will be trying to fine tune the Wenatchee Area and
deciding whether to include any winter highlights. The snowfall
for Wenatchee Area looks ok, (one inch) but higher amounts could
will be possible in northern sections of the zones up near Chelan
and across the higher benches. But here is where it gets
challenging, BUFKIT sounding data suggest a warm nose into
Wenatchee while the MOS guidance keeps surface temperatures at or
below freezing. This raises concern that when the transition from
snow to rain occurs, precip may be in the form of freezing rain or
sleet. There is always the potential that the models are warming
too fast aloft and it all remains snow. We feel confident for
moderate QPF...but precip type will be difficult in an area with
so many microclimates. This is something that may be addressed
with a winter storm update this evening or potentially overnight.
/sb


&&

.AVIATION...
00Z TAFS: MVFR Ceilings and vis will be common over the region
through tonight as a moist boundary layer and light winds exists
under a strong low level inversion...with IFR conditions likely
redeveloping mainly at the KMWH and KGEG vicinity TAF sites
overnight. On Friday an approaching Pacific storm system will
spread thickening clouds over the region as a warm front develops.
MVFR ceilings will probably remain common across the Columbia
basin except fro KLWS where VFR conditions are expected. Light
snow or rain may begin at the KEAT TAF site during the afternoon.
/MJF



&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        28  37  36  43  30  40 /  20  30 100  30  20  60
Coeur d`Alene  30  39  36  42  31  39 /  30  50 100  50  30  70
Pullman        33  41  36  43  34  42 /  10  10 100  70  40  60
Lewiston       35  44  40  48  36  47 /  10  10 100  70  30  50
Colville       27  37  34  44  20  38 /  30  70 100  50  10  60
Sandpoint      29  37  35  41  29  37 /  50  70 100  70  30  70
Kellogg        31  37  36  39  32  36 /  40  50 100  80  60  80
Moses Lake     26  36  35  48  30  46 /  10  50 100  10  10  30
Wenatchee      30  35  35  47  34  45 /  10  80 100  10  10  40
Omak           30  35  33  45  27  39 /  10  90 100  20  10  40

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Air Stagnation Advisory until Noon PST Friday for Central
     Panhandle Mountains-Coeur d`Alene Area-Idaho Palouse-
     Northern Panhandle.

     Winter Storm Warning from Noon Friday to 6 PM PST Saturday for
     Northern Panhandle.

     Winter Storm Warning from Noon Friday to 6 AM PST Sunday for
     Central Panhandle Mountains.

WA...Air Stagnation Advisory until Noon PST Friday for East Slopes
     Northern Cascades-Lower Garfield and Asotin Counties-Moses
     Lake Area-Northeast Mountains-Okanogan Highlands-Spokane
     Area-Upper Columbia Basin-Washington Palouse-Waterville
     Plateau-Wenatchee Area.

     Winter Storm Warning from Noon Friday to 6 AM PST Saturday for
     East Slopes Northern Cascades-Okanogan Highlands-Okanogan
     Valley-Waterville Plateau.

     Winter Storm Warning from Noon Friday to 6 PM PST Saturday for
     Northeast Mountains.

&&

$$





000
FXUS66 KOTX 210457
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
857 PM PST THU NOV 20 2014

.SYNOPSIS...
A relatively quiet and cool overnight period with a few snow
showers over the north will give way to a sharp deterioration in
the weather on Friday as a strong and moist Pacific storm brings
valley rain and mountain snow Friday night followed by very windy
conditions on Saturday. An active and periodically wet weather
regime will continue through the next week.


&&

.DISCUSSION...

...REFREEZING ROADS AND POTENTIAL FOR additional FREEZING DRIZZLE
TO CREATE SLICK TRAVEL OVERNIGHT...

Evening update: A complex and active winter weather pattern will
be the focus for the next 36 hours. Here are the changes we have
made or will be focusing on tonight.

For tonight, we have added patchy freezing drizzle to majority of
the Columbia Basin, West Plains, and northern Palouse. Light
echoes continue to blossom across the region as warm air
advection/isentropic ascent strengthens ahead of a
weak...splitting trof currently moving across the Cascades.
Further investigation into soundings suggest the moisture will
generally remain below the dendritic layer (ie. drizzle) ahead
and behind the weak wave but could briefly saturate this layer as
it passes through. While confidence is generally low, this would
indicate drizzle falling out of the stratus (low clouds)...briefly
becoming snow, sleet, or rain/freezing rain, then transitioning
back to drizzle. This is where surface temperatures become very
important. Most locations remain below freezing at this hour. The
exception is the Palouse, L-C Valley, and Camas Prairie which are
in the upper 30s to lower 40s and carrying dewpoints in the mid
30s suggesting temperatures will not fall much tonight away from
the mid 30s. On top of that, moisture from earlier precipitation
will likely refreeze to surfaces. All things considered, there is
a good chance that motorists will encounter icy travel across much
of the region.

For Friday, we will be trying to fine tune the Wenatchee Area and
deciding whether to include any winter highlights. The snowfall
for Wenatchee Area looks ok, (one inch) but higher amounts could
will be possible in northern sections of the zones up near Chelan
and across the higher benches. But here is where it gets
challenging, BUFKIT sounding data suggest a warm nose into
Wenatchee while the MOS guidance keeps surface temperatures at or
below freezing. This raises concern that when the transition from
snow to rain occurs, precip may be in the form of freezing rain or
sleet. There is always the potential that the models are warming
too fast aloft and it all remains snow. We feel confident for
moderate QPF...but precip type will be difficult in an area with
so many microclimates. This is something that may be addressed
with a winter storm update this evening or potentially overnight.
/sb


&&

.AVIATION...
00Z TAFS: MVFR Ceilings and vis will be common over the region
through tonight as a moist boundary layer and light winds exists
under a strong low level inversion...with IFR conditions likely
redeveloping mainly at the KMWH and KGEG vicinity TAF sites
overnight. On Friday an approaching Pacific storm system will
spread thickening clouds over the region as a warm front develops.
MVFR ceilings will probably remain common across the Columbia
basin except fro KLWS where VFR conditions are expected. Light
snow or rain may begin at the KEAT TAF site during the afternoon.
/MJF



&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        28  37  36  43  30  40 /  20  30 100  30  20  60
Coeur d`Alene  30  39  36  42  31  39 /  30  50 100  50  30  70
Pullman        33  41  36  43  34  42 /  10  10 100  70  40  60
Lewiston       35  44  40  48  36  47 /  10  10 100  70  30  50
Colville       27  37  34  44  20  38 /  30  70 100  50  10  60
Sandpoint      29  37  35  41  29  37 /  50  70 100  70  30  70
Kellogg        31  37  36  39  32  36 /  40  50 100  80  60  80
Moses Lake     26  36  35  48  30  46 /  10  50 100  10  10  30
Wenatchee      30  35  35  47  34  45 /  10  80 100  10  10  40
Omak           30  35  33  45  27  39 /  10  90 100  20  10  40

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Air Stagnation Advisory until Noon PST Friday for Central
     Panhandle Mountains-Coeur d`Alene Area-Idaho Palouse-
     Northern Panhandle.

     Winter Storm Warning from Noon Friday to 6 PM PST Saturday for
     Northern Panhandle.

     Winter Storm Warning from Noon Friday to 6 AM PST Sunday for
     Central Panhandle Mountains.

WA...Air Stagnation Advisory until Noon PST Friday for East Slopes
     Northern Cascades-Lower Garfield and Asotin Counties-Moses
     Lake Area-Northeast Mountains-Okanogan Highlands-Spokane
     Area-Upper Columbia Basin-Washington Palouse-Waterville
     Plateau-Wenatchee Area.

     Winter Storm Warning from Noon Friday to 6 AM PST Saturday for
     East Slopes Northern Cascades-Okanogan Highlands-Okanogan
     Valley-Waterville Plateau.

     Winter Storm Warning from Noon Friday to 6 PM PST Saturday for
     Northeast Mountains.

&&

$$




000
FXUS66 KSEW 210451 CCA
AFDSEW

AREA FORECAST DISCUSSION...CORRECTION
NATIONAL WEATHER SERVICE SEATTLE WA
900 PM PST THU NOV 20 2014

CORRECTION TO WATCH/WARNING/ADVISORY SECTION BELOW.

.SYNOPSIS...A PACIFIC STORM WILL IMPACT THE REGION ON FRIDAY AND
FRIDAY NIGHT WITH LOCALLY HEAVY RAIN AND GUSTY WINDS...ALONG WITH
DECENT SNOWFALL IN THE CASCADES FROM STEVENS PASS NORTHWARD. THE
WEATHER PATTERN WILL REMAIN WET AND UNSETTLED THIS WEEKEND WITH
ANOTHER WEATHER SYSTEM IMPACTING THE AREA ON SUNDAY. MUCH
UNCERTAINTY EXISTS IN THE FORECAST FROM MONDAY ONWARD.

&&

.SHORT TERM...SHOWERS ARE WINDING DOWN ACROSS WESTERN WA THIS
EVENING...MAINLY AFFECTING THE NORTH CASCADES. SKIES WILL REMAIN
CLOUDY OVERNIGHT WITH LOWS IN THE 40S. CURRENT FORECAST IS ON TRACK.

A STRONG PACIFIC FRONTAL SYSTEM WILL BRING RAIN...MOUNTAIN SNOW AND
LOCALLY WINDY CONDITIONS AS IT MOVE INLAND FRI AND FRI NIGHT. WIND
ADVISORIES ARE IN EFFECT FOR THE COAST...SAN JUANS AND WESTERN
WHATCOM. RAIN WILL REACH THE COAST FRI MORNING...THEN SPREAD INLAND
BY THE AFTERNOON. THE COAST MAY SEE 1-2 INCHES OF RAIN...WITH 0.5 TO
1 INCH IN THE INTERIOR. SNOW LEVELS WILL HOVER AROUND 4000 FT WITH
SNOW EXPECTED AT STEVENS PASS AND WASHINGTON PASS...WITH UP TO 6
INCHES OF SNOW POSSIBLE THROUGH FRI NIGHT. SNOQUALMIE PASS SHOULD
SEE RAIN. A WINTER WEATHER ADVISORY IS IN EFFECT FOR THE CASCADES
FROM KING COUNTY NORTH OVER 4000 FT. SHOWERS WILL TAPER DOWN LATE
FRI NIGHT AS THIS SYSTEM EXITS.

MOIST ONSHORE FLOW CONTINUES ON SAT FOR ADDITIONAL SHOWERS ACROSS
THE AREA...WITH MORE SNOW IN THE MOUNTAINS. MAY SEE A PUGET SOUND
CONVERGENCE ZONE DEVELOP SAT AFTERNOON.

ANOTHER STRONG PACIFIC FRONT WILL BRING MORE RAIN AND MOUNTAIN SNOW
ON SUNDAY. 33

.LONG TERM...PREVIOUS DISCUSSION...MONDAY THROUGH WEDNESDAY...BOTH
THE GFS AND ECMWF SHOW MOISTURE BEING TRANSPORTED TO THE PACIFIC NW
VIA THE JET STREAM...HOWEVER THE GFS HAS THE MOISTURE HITTING SW BC
FOR THE MOST PART AND US STAYING DRY...WHEREAS THE ECMWF HAS A
WETTER SOLUTION FOR US WITH THE MOISTURE HITTING US DIRECTLY.
THEREFORE MUCH UNCERTAINTY EXISTS IN THE FORECAST. THURSDAY LOOKS
DRY WITH A RIDGE BUILDING IN ON BOTH MODELS...BUT IT IS TOO EARLY TO
TELL WITH MUCH CERTAINTY. JSMITH

&&

.HYDROLOGY...RIVER FLOODING IS NOT EXPECTED THE NEXT 7 DAYS.

&&

.AVIATION...WESTERLY FLOW ALOFT WILL INCREASE TONIGHT AS A STRONG
FRONTAL SYSTEM APPROACHES THE COAST. THE AIR MASS IS MOIST AND
STABLE EXCEPT FOR ISOLATED SHOWERS NORTH PART. RAIN FROM THE
APPROACHING FRONT WILL SPREAD INLAND AROUND 15Z. FROPA ON THE COAST
SHOULD BE AROUND 00Z...AND OVER PUGET SOUND AROUND 04Z. AT THE
SURFACE STRONG GUSTY SOUTHEAST WINDS WILL DEVELOP ALONG THE COAST
AND OVER PARTS OF THE NORTH INTERIOR ON FRIDAY.

CEILINGS THIS EVENING ARE GENERALLY VFR 4K-6K FT. LOCAL FOG WITH
VISIBILITIES 1/2SM ARE POSSIBLE TONIGHT. BY FRIDAY MORNING MOST
CEILINGS WILL FALL TO MVFR 2K-3K FT IN RAIN.

KSEA...DISCUSSION ABOVE APPLIES EXCEPT FOG IS UNLIKELY TONIGHT.
WINDS SOUTHEAST 4-8 KT. RAIN AND MVFR CONDITIONS WILL PREDOMINATE ON
FRIDAY. WINDS WILL RISE TO SOUTHERLY 8-12 KT IN THE AFTERNOON. CHB

&&

.MARINE...A STRONG FRONTAL SYSTEM WILL MOVE THROUGH THE AREA FRIDAY.
MODELS SHOW GALES OVER THE COASTAL WATERS STARTING FRIDAY AFTERNOON
AND OVER THE EAST ENTRANCE AND NORTH INLAND WATERS FRIDAY AFTERNOON
AND EVENING. SMALL CRAFT ADVISORY WINDS ARE EXPECTED OVER THE REST
OF THE WATERS. FROPA ALONG THE COAST SHOULD BE AROUND 00Z...THEN
AROUND 04Z OVER PUGET SOUND. A WESTERLY PUSH BEHIND THE FRONT SHOULD
PRODUCE SMALL CRAFT ADVISORY WEST WINDS THROUGH THE STRAIT AND OVER
THE NORTHERN INLAND WATERS.

WESTERLY FLOW ALOFT OVER THE NORTHEAST PACIFIC SATURDAY THROUGH
MONDAY WILL BRING SEVERAL WEAKER SURFACE TROUGHS ACROSS THE AREA.
CONFIDENCE IN THE TIMING AND STRENGTH OF EACH OF THESE TROUGHS IS
LOW...BUT THEY COULD PRODUCE SOLID ADVISORY LEVEL WINDS AND PERHAPS
SPOTTY GALES. SWELLS IN THE 15-20 FOOT RANGE ARE FORECAST TO REACH
THE COAST SUNDAY. CHB

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...WINTER WEATHER ADVISORY CASCADES FROM KING TO WHATCOM COUNTIES.
     WIND ADVISORY NORTH AND CENTRAL COAST...THE SAN JUAN
     ISLANDS...AND WESTERN WHATCOM COUNTY.
PZ...GALE WARNING COAST...EAST ENTRANCE...NORTH INLAND WATERS.
     SMALL CRAFT ADVISORY ALL REMAINING WATERS.
     SMALL CRAFT ADVISORY FOR ROUGH GRAYS HARBOR BAR.

&&

$$

WWW.WEATHER.GOV/SEATTLE

YOU CAN SEE AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML






000
FXUS66 KSEW 210449
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
900 PM PST THU NOV 20 2014

.SYNOPSIS...A PACIFIC STORM WILL IMPACT THE REGION ON FRIDAY AND
FRIDAY NIGHT WITH LOCALLY HEAVY RAIN AND GUSTY WINDS...ALONG WITH
DECENT SNOWFALL IN THE CASCADES FROM STEVENS PASS NORTHWARD. THE
WEATHER PATTERN WILL REMAIN WET AND UNSETTLED THIS WEEKEND WITH
ANOTHER WEATHER SYSTEM IMPACTING THE AREA ON SUNDAY. MUCH
UNCERTAINTY EXISTS IN THE FORECAST FROM MONDAY ONWARD.

&&

.SHORT TERM...SHOWERS ARE WINDING DOWN ACROSS WESTERN WA THIS
EVENING...MAINLY AFFECTING THE NORTH CASCADES. SKIES WILL REMAIN
CLOUDY OVERNIGHT WITH LOWS IN THE 40S. CURRENT FORECAST IS ON TRACK.

A STRONG PACIFIC FRONTAL SYSTEM WILL BRING RAIN...MOUNTAIN SNOW AND
LOCALLY WINDY CONDITIONS AS IT MOVE INLAND FRI AND FRI NIGHT. WIND
ADVISORIES ARE IN EFFECT FOR THE COAST...SAN JUANS AND WESTERN
WHATCOM. RAIN WILL REACH THE COAST FRI MORNING...THEN SPREAD INLAND
BY THE AFTERNOON. THE COAST MAY SEE 1-2 INCHES OF RAIN...WITH 0.5 TO
1 INCH IN THE INTERIOR. SNOW LEVELS WILL HOVER AROUND 4000 FT WITH
SNOW EXPECTED AT STEVENS PASS AND WASHINGTON PASS...WITH UP TO 6
INCHES OF SNOW POSSIBLE THROUGH FRI NIGHT. SNOQUALMIE PASS SHOULD
SEE RAIN. A WINTER WEATHER ADVISORY IS IN EFFECT FOR THE CASCADES
FROM KING COUNTY NORTH OVER 4000 FT. SHOWERS WILL TAPER DOWN LATE
FRI NIGHT AS THIS SYSTEM EXITS.

MOIST ONSHORE FLOW CONTINUES ON SAT FOR ADDITIONAL SHOWERS ACROSS
THE AREA...WITH MORE SNOW IN THE MOUNTAINS. MAY SEE A PUGET SOUND
CONVERGENCE ZONE DEVELOP SAT AFTERNOON.

ANOTHER STRONG PACIFIC FRONT WILL BRING MORE RAIN AND MOUNTAIN SNOW
ON SUNDAY. 33

.LONG TERM...PREVIOUS DISCUSSION...MONDAY THROUGH WEDNESDAY...BOTH
THE GFS AND ECMWF SHOW MOISTURE BEING TRANSPORTED TO THE PACIFIC NW
VIA THE JET STREAM...HOWEVER THE GFS HAS THE MOISTURE HITTING SW BC
FOR THE MOST PART AND US STAYING DRY...WHEREAS THE ECMWF HAS A
WETTER SOLUTION FOR US WITH THE MOISTURE HITTING US DIRECTLY.
THEREFORE MUCH UNCERTAINTY EXISTS IN THE FORECAST. THURSDAY LOOKS
DRY WITH A RIDGE BUILDING IN ON BOTH MODELS...BUT IT IS TOO EARLY TO
TELL WITH MUCH CERTAINTY. JSMITH

&&

.HYDROLOGY...RIVER FLOODING IS NOT EXPECTED THE NEXT 7 DAYS.

&&

.AVIATION...WESTERLY FLOW ALOFT WILL INCREASE TONIGHT AS A STRONG
FRONTAL SYSTEM APPROACHES THE COAST. THE AIR MASS IS MOIST AND
STABLE EXCEPT FOR ISOLATED SHOWERS NORTH PART. RAIN FROM THE
APPROACHING FRONT WILL SPREAD INLAND AROUND 15Z. FROPA ON THE COAST
SHOULD BE AROUND 00Z...AND OVER PUGET SOUND AROUND 04Z. AT THE
SURFACE STRONG GUSTY SOUTHEAST WINDS WILL DEVELOP ALONG THE COAST
AND OVER PARTS OF THE NORTH INTERIOR ON FRIDAY.

CEILINGS THIS EVENING ARE GENERALLY VFR 4K-6K FT. LOCAL FOG WITH
VISIBILITIES 1/2SM ARE POSSIBLE TONIGHT. BY FRIDAY MORNING MOST
CEILINGS WILL FALL TO MVFR 2K-3K FT IN RAIN.

KSEA...DISCUSSION ABOVE APPLIES EXCEPT FOG IS UNLIKELY TONIGHT.
WINDS SOUTHEAST 4-8 KT. RAIN AND MVFR CONDITIONS WILL PREDOMINATE ON
FRIDAY. WINDS WILL RISE TO SOUTHERLY 8-12 KT IN THE AFTERNOON. CHB

&&

.MARINE...A STRONG FRONTAL SYSTEM WILL MOVE THROUGH THE AREA FRIDAY.
MODELS SHOW GALES OVER THE COASTAL WATERS STARTING FRIDAY AFTERNOON
AND OVER THE EAST ENTRANCE AND NORTH INLAND WATERS FRIDAY AFTERNOON
AND EVENING. SMALL CRAFT ADVISORY WINDS ARE EXPECTED OVER THE REST
OF THE WATERS. FROPA ALONG THE COAST SHOULD BE AROUND 00Z...THEN
AROUND 04Z OVER PUGET SOUND. A WESTERLY PUSH BEHIND THE FRONT SHOULD
PRODUCE SMALL CRAFT ADVISORY WEST WINDS THROUGH THE STRAIT AND OVER
THE NORTHERN INLAND WATERS.

WESTERLY FLOW ALOFT OVER THE NORTHEAST PACIFIC SATURDAY THROUGH
MONDAY WILL BRING SEVERAL WEAKER SURFACE TROUGHS ACROSS THE AREA.
CONFIDENCE IN THE TIMING AND STRENGTH OF EACH OF THESE TROUGHS IS
LOW...BUT THEY COULD PRODUCE SOLID ADVISORY LEVEL WINDS AND PERHAPS
SPOTTY GALES. SWELLS IN THE 15-20 FOOT RANGE ARE FORECAST TO REACH
THE COAST SUNDAY. CHB

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...WINTER WEATHER ADVISORY NORTH AND NORTH CENTRAL CASCADES.
     WIND ADVISORY NORTH AND CENTRAL COAST...THE SAN JUAN
     ISLANDS...AND WESTERN WHATCOM COUNTY.
PZ...GALE WARNING COAST...EAST ENTRANCE...NORTH INLAND WATERS.
     SMALL CRAFT ADVISORY ALL REMAINING WATERS.
     SMALL CRAFT ADVISORY FOR ROUGH GRAYS HARBOR BAR.

&&

$$

WWW.WEATHER.GOV/SEATTLE

YOU CAN SEE AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML





000
FXUS66 KSEW 210449
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
900 PM PST THU NOV 20 2014

.SYNOPSIS...A PACIFIC STORM WILL IMPACT THE REGION ON FRIDAY AND
FRIDAY NIGHT WITH LOCALLY HEAVY RAIN AND GUSTY WINDS...ALONG WITH
DECENT SNOWFALL IN THE CASCADES FROM STEVENS PASS NORTHWARD. THE
WEATHER PATTERN WILL REMAIN WET AND UNSETTLED THIS WEEKEND WITH
ANOTHER WEATHER SYSTEM IMPACTING THE AREA ON SUNDAY. MUCH
UNCERTAINTY EXISTS IN THE FORECAST FROM MONDAY ONWARD.

&&

.SHORT TERM...SHOWERS ARE WINDING DOWN ACROSS WESTERN WA THIS
EVENING...MAINLY AFFECTING THE NORTH CASCADES. SKIES WILL REMAIN
CLOUDY OVERNIGHT WITH LOWS IN THE 40S. CURRENT FORECAST IS ON TRACK.

A STRONG PACIFIC FRONTAL SYSTEM WILL BRING RAIN...MOUNTAIN SNOW AND
LOCALLY WINDY CONDITIONS AS IT MOVE INLAND FRI AND FRI NIGHT. WIND
ADVISORIES ARE IN EFFECT FOR THE COAST...SAN JUANS AND WESTERN
WHATCOM. RAIN WILL REACH THE COAST FRI MORNING...THEN SPREAD INLAND
BY THE AFTERNOON. THE COAST MAY SEE 1-2 INCHES OF RAIN...WITH 0.5 TO
1 INCH IN THE INTERIOR. SNOW LEVELS WILL HOVER AROUND 4000 FT WITH
SNOW EXPECTED AT STEVENS PASS AND WASHINGTON PASS...WITH UP TO 6
INCHES OF SNOW POSSIBLE THROUGH FRI NIGHT. SNOQUALMIE PASS SHOULD
SEE RAIN. A WINTER WEATHER ADVISORY IS IN EFFECT FOR THE CASCADES
FROM KING COUNTY NORTH OVER 4000 FT. SHOWERS WILL TAPER DOWN LATE
FRI NIGHT AS THIS SYSTEM EXITS.

MOIST ONSHORE FLOW CONTINUES ON SAT FOR ADDITIONAL SHOWERS ACROSS
THE AREA...WITH MORE SNOW IN THE MOUNTAINS. MAY SEE A PUGET SOUND
CONVERGENCE ZONE DEVELOP SAT AFTERNOON.

ANOTHER STRONG PACIFIC FRONT WILL BRING MORE RAIN AND MOUNTAIN SNOW
ON SUNDAY. 33

.LONG TERM...PREVIOUS DISCUSSION...MONDAY THROUGH WEDNESDAY...BOTH
THE GFS AND ECMWF SHOW MOISTURE BEING TRANSPORTED TO THE PACIFIC NW
VIA THE JET STREAM...HOWEVER THE GFS HAS THE MOISTURE HITTING SW BC
FOR THE MOST PART AND US STAYING DRY...WHEREAS THE ECMWF HAS A
WETTER SOLUTION FOR US WITH THE MOISTURE HITTING US DIRECTLY.
THEREFORE MUCH UNCERTAINTY EXISTS IN THE FORECAST. THURSDAY LOOKS
DRY WITH A RIDGE BUILDING IN ON BOTH MODELS...BUT IT IS TOO EARLY TO
TELL WITH MUCH CERTAINTY. JSMITH

&&

.HYDROLOGY...RIVER FLOODING IS NOT EXPECTED THE NEXT 7 DAYS.

&&

.AVIATION...WESTERLY FLOW ALOFT WILL INCREASE TONIGHT AS A STRONG
FRONTAL SYSTEM APPROACHES THE COAST. THE AIR MASS IS MOIST AND
STABLE EXCEPT FOR ISOLATED SHOWERS NORTH PART. RAIN FROM THE
APPROACHING FRONT WILL SPREAD INLAND AROUND 15Z. FROPA ON THE COAST
SHOULD BE AROUND 00Z...AND OVER PUGET SOUND AROUND 04Z. AT THE
SURFACE STRONG GUSTY SOUTHEAST WINDS WILL DEVELOP ALONG THE COAST
AND OVER PARTS OF THE NORTH INTERIOR ON FRIDAY.

CEILINGS THIS EVENING ARE GENERALLY VFR 4K-6K FT. LOCAL FOG WITH
VISIBILITIES 1/2SM ARE POSSIBLE TONIGHT. BY FRIDAY MORNING MOST
CEILINGS WILL FALL TO MVFR 2K-3K FT IN RAIN.

KSEA...DISCUSSION ABOVE APPLIES EXCEPT FOG IS UNLIKELY TONIGHT.
WINDS SOUTHEAST 4-8 KT. RAIN AND MVFR CONDITIONS WILL PREDOMINATE ON
FRIDAY. WINDS WILL RISE TO SOUTHERLY 8-12 KT IN THE AFTERNOON. CHB

&&

.MARINE...A STRONG FRONTAL SYSTEM WILL MOVE THROUGH THE AREA FRIDAY.
MODELS SHOW GALES OVER THE COASTAL WATERS STARTING FRIDAY AFTERNOON
AND OVER THE EAST ENTRANCE AND NORTH INLAND WATERS FRIDAY AFTERNOON
AND EVENING. SMALL CRAFT ADVISORY WINDS ARE EXPECTED OVER THE REST
OF THE WATERS. FROPA ALONG THE COAST SHOULD BE AROUND 00Z...THEN
AROUND 04Z OVER PUGET SOUND. A WESTERLY PUSH BEHIND THE FRONT SHOULD
PRODUCE SMALL CRAFT ADVISORY WEST WINDS THROUGH THE STRAIT AND OVER
THE NORTHERN INLAND WATERS.

WESTERLY FLOW ALOFT OVER THE NORTHEAST PACIFIC SATURDAY THROUGH
MONDAY WILL BRING SEVERAL WEAKER SURFACE TROUGHS ACROSS THE AREA.
CONFIDENCE IN THE TIMING AND STRENGTH OF EACH OF THESE TROUGHS IS
LOW...BUT THEY COULD PRODUCE SOLID ADVISORY LEVEL WINDS AND PERHAPS
SPOTTY GALES. SWELLS IN THE 15-20 FOOT RANGE ARE FORECAST TO REACH
THE COAST SUNDAY. CHB

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...WINTER WEATHER ADVISORY NORTH AND NORTH CENTRAL CASCADES.
     WIND ADVISORY NORTH AND CENTRAL COAST...THE SAN JUAN
     ISLANDS...AND WESTERN WHATCOM COUNTY.
PZ...GALE WARNING COAST...EAST ENTRANCE...NORTH INLAND WATERS.
     SMALL CRAFT ADVISORY ALL REMAINING WATERS.
     SMALL CRAFT ADVISORY FOR ROUGH GRAYS HARBOR BAR.

&&

$$

WWW.WEATHER.GOV/SEATTLE

YOU CAN SEE AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML





000
FXUS66 KSEW 210449
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
900 PM PST THU NOV 20 2014

.SYNOPSIS...A PACIFIC STORM WILL IMPACT THE REGION ON FRIDAY AND
FRIDAY NIGHT WITH LOCALLY HEAVY RAIN AND GUSTY WINDS...ALONG WITH
DECENT SNOWFALL IN THE CASCADES FROM STEVENS PASS NORTHWARD. THE
WEATHER PATTERN WILL REMAIN WET AND UNSETTLED THIS WEEKEND WITH
ANOTHER WEATHER SYSTEM IMPACTING THE AREA ON SUNDAY. MUCH
UNCERTAINTY EXISTS IN THE FORECAST FROM MONDAY ONWARD.

&&

.SHORT TERM...SHOWERS ARE WINDING DOWN ACROSS WESTERN WA THIS
EVENING...MAINLY AFFECTING THE NORTH CASCADES. SKIES WILL REMAIN
CLOUDY OVERNIGHT WITH LOWS IN THE 40S. CURRENT FORECAST IS ON TRACK.

A STRONG PACIFIC FRONTAL SYSTEM WILL BRING RAIN...MOUNTAIN SNOW AND
LOCALLY WINDY CONDITIONS AS IT MOVE INLAND FRI AND FRI NIGHT. WIND
ADVISORIES ARE IN EFFECT FOR THE COAST...SAN JUANS AND WESTERN
WHATCOM. RAIN WILL REACH THE COAST FRI MORNING...THEN SPREAD INLAND
BY THE AFTERNOON. THE COAST MAY SEE 1-2 INCHES OF RAIN...WITH 0.5 TO
1 INCH IN THE INTERIOR. SNOW LEVELS WILL HOVER AROUND 4000 FT WITH
SNOW EXPECTED AT STEVENS PASS AND WASHINGTON PASS...WITH UP TO 6
INCHES OF SNOW POSSIBLE THROUGH FRI NIGHT. SNOQUALMIE PASS SHOULD
SEE RAIN. A WINTER WEATHER ADVISORY IS IN EFFECT FOR THE CASCADES
FROM KING COUNTY NORTH OVER 4000 FT. SHOWERS WILL TAPER DOWN LATE
FRI NIGHT AS THIS SYSTEM EXITS.

MOIST ONSHORE FLOW CONTINUES ON SAT FOR ADDITIONAL SHOWERS ACROSS
THE AREA...WITH MORE SNOW IN THE MOUNTAINS. MAY SEE A PUGET SOUND
CONVERGENCE ZONE DEVELOP SAT AFTERNOON.

ANOTHER STRONG PACIFIC FRONT WILL BRING MORE RAIN AND MOUNTAIN SNOW
ON SUNDAY. 33

.LONG TERM...PREVIOUS DISCUSSION...MONDAY THROUGH WEDNESDAY...BOTH
THE GFS AND ECMWF SHOW MOISTURE BEING TRANSPORTED TO THE PACIFIC NW
VIA THE JET STREAM...HOWEVER THE GFS HAS THE MOISTURE HITTING SW BC
FOR THE MOST PART AND US STAYING DRY...WHEREAS THE ECMWF HAS A
WETTER SOLUTION FOR US WITH THE MOISTURE HITTING US DIRECTLY.
THEREFORE MUCH UNCERTAINTY EXISTS IN THE FORECAST. THURSDAY LOOKS
DRY WITH A RIDGE BUILDING IN ON BOTH MODELS...BUT IT IS TOO EARLY TO
TELL WITH MUCH CERTAINTY. JSMITH

&&

.HYDROLOGY...RIVER FLOODING IS NOT EXPECTED THE NEXT 7 DAYS.

&&

.AVIATION...WESTERLY FLOW ALOFT WILL INCREASE TONIGHT AS A STRONG
FRONTAL SYSTEM APPROACHES THE COAST. THE AIR MASS IS MOIST AND
STABLE EXCEPT FOR ISOLATED SHOWERS NORTH PART. RAIN FROM THE
APPROACHING FRONT WILL SPREAD INLAND AROUND 15Z. FROPA ON THE COAST
SHOULD BE AROUND 00Z...AND OVER PUGET SOUND AROUND 04Z. AT THE
SURFACE STRONG GUSTY SOUTHEAST WINDS WILL DEVELOP ALONG THE COAST
AND OVER PARTS OF THE NORTH INTERIOR ON FRIDAY.

CEILINGS THIS EVENING ARE GENERALLY VFR 4K-6K FT. LOCAL FOG WITH
VISIBILITIES 1/2SM ARE POSSIBLE TONIGHT. BY FRIDAY MORNING MOST
CEILINGS WILL FALL TO MVFR 2K-3K FT IN RAIN.

KSEA...DISCUSSION ABOVE APPLIES EXCEPT FOG IS UNLIKELY TONIGHT.
WINDS SOUTHEAST 4-8 KT. RAIN AND MVFR CONDITIONS WILL PREDOMINATE ON
FRIDAY. WINDS WILL RISE TO SOUTHERLY 8-12 KT IN THE AFTERNOON. CHB

&&

.MARINE...A STRONG FRONTAL SYSTEM WILL MOVE THROUGH THE AREA FRIDAY.
MODELS SHOW GALES OVER THE COASTAL WATERS STARTING FRIDAY AFTERNOON
AND OVER THE EAST ENTRANCE AND NORTH INLAND WATERS FRIDAY AFTERNOON
AND EVENING. SMALL CRAFT ADVISORY WINDS ARE EXPECTED OVER THE REST
OF THE WATERS. FROPA ALONG THE COAST SHOULD BE AROUND 00Z...THEN
AROUND 04Z OVER PUGET SOUND. A WESTERLY PUSH BEHIND THE FRONT SHOULD
PRODUCE SMALL CRAFT ADVISORY WEST WINDS THROUGH THE STRAIT AND OVER
THE NORTHERN INLAND WATERS.

WESTERLY FLOW ALOFT OVER THE NORTHEAST PACIFIC SATURDAY THROUGH
MONDAY WILL BRING SEVERAL WEAKER SURFACE TROUGHS ACROSS THE AREA.
CONFIDENCE IN THE TIMING AND STRENGTH OF EACH OF THESE TROUGHS IS
LOW...BUT THEY COULD PRODUCE SOLID ADVISORY LEVEL WINDS AND PERHAPS
SPOTTY GALES. SWELLS IN THE 15-20 FOOT RANGE ARE FORECAST TO REACH
THE COAST SUNDAY. CHB

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...WINTER WEATHER ADVISORY NORTH AND NORTH CENTRAL CASCADES.
     WIND ADVISORY NORTH AND CENTRAL COAST...THE SAN JUAN
     ISLANDS...AND WESTERN WHATCOM COUNTY.
PZ...GALE WARNING COAST...EAST ENTRANCE...NORTH INLAND WATERS.
     SMALL CRAFT ADVISORY ALL REMAINING WATERS.
     SMALL CRAFT ADVISORY FOR ROUGH GRAYS HARBOR BAR.

&&

$$

WWW.WEATHER.GOV/SEATTLE

YOU CAN SEE AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML





000
FXUS66 KSEW 210449
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
900 PM PST THU NOV 20 2014

.SYNOPSIS...A PACIFIC STORM WILL IMPACT THE REGION ON FRIDAY AND
FRIDAY NIGHT WITH LOCALLY HEAVY RAIN AND GUSTY WINDS...ALONG WITH
DECENT SNOWFALL IN THE CASCADES FROM STEVENS PASS NORTHWARD. THE
WEATHER PATTERN WILL REMAIN WET AND UNSETTLED THIS WEEKEND WITH
ANOTHER WEATHER SYSTEM IMPACTING THE AREA ON SUNDAY. MUCH
UNCERTAINTY EXISTS IN THE FORECAST FROM MONDAY ONWARD.

&&

.SHORT TERM...SHOWERS ARE WINDING DOWN ACROSS WESTERN WA THIS
EVENING...MAINLY AFFECTING THE NORTH CASCADES. SKIES WILL REMAIN
CLOUDY OVERNIGHT WITH LOWS IN THE 40S. CURRENT FORECAST IS ON TRACK.

A STRONG PACIFIC FRONTAL SYSTEM WILL BRING RAIN...MOUNTAIN SNOW AND
LOCALLY WINDY CONDITIONS AS IT MOVE INLAND FRI AND FRI NIGHT. WIND
ADVISORIES ARE IN EFFECT FOR THE COAST...SAN JUANS AND WESTERN
WHATCOM. RAIN WILL REACH THE COAST FRI MORNING...THEN SPREAD INLAND
BY THE AFTERNOON. THE COAST MAY SEE 1-2 INCHES OF RAIN...WITH 0.5 TO
1 INCH IN THE INTERIOR. SNOW LEVELS WILL HOVER AROUND 4000 FT WITH
SNOW EXPECTED AT STEVENS PASS AND WASHINGTON PASS...WITH UP TO 6
INCHES OF SNOW POSSIBLE THROUGH FRI NIGHT. SNOQUALMIE PASS SHOULD
SEE RAIN. A WINTER WEATHER ADVISORY IS IN EFFECT FOR THE CASCADES
FROM KING COUNTY NORTH OVER 4000 FT. SHOWERS WILL TAPER DOWN LATE
FRI NIGHT AS THIS SYSTEM EXITS.

MOIST ONSHORE FLOW CONTINUES ON SAT FOR ADDITIONAL SHOWERS ACROSS
THE AREA...WITH MORE SNOW IN THE MOUNTAINS. MAY SEE A PUGET SOUND
CONVERGENCE ZONE DEVELOP SAT AFTERNOON.

ANOTHER STRONG PACIFIC FRONT WILL BRING MORE RAIN AND MOUNTAIN SNOW
ON SUNDAY. 33

.LONG TERM...PREVIOUS DISCUSSION...MONDAY THROUGH WEDNESDAY...BOTH
THE GFS AND ECMWF SHOW MOISTURE BEING TRANSPORTED TO THE PACIFIC NW
VIA THE JET STREAM...HOWEVER THE GFS HAS THE MOISTURE HITTING SW BC
FOR THE MOST PART AND US STAYING DRY...WHEREAS THE ECMWF HAS A
WETTER SOLUTION FOR US WITH THE MOISTURE HITTING US DIRECTLY.
THEREFORE MUCH UNCERTAINTY EXISTS IN THE FORECAST. THURSDAY LOOKS
DRY WITH A RIDGE BUILDING IN ON BOTH MODELS...BUT IT IS TOO EARLY TO
TELL WITH MUCH CERTAINTY. JSMITH

&&

.HYDROLOGY...RIVER FLOODING IS NOT EXPECTED THE NEXT 7 DAYS.

&&

.AVIATION...WESTERLY FLOW ALOFT WILL INCREASE TONIGHT AS A STRONG
FRONTAL SYSTEM APPROACHES THE COAST. THE AIR MASS IS MOIST AND
STABLE EXCEPT FOR ISOLATED SHOWERS NORTH PART. RAIN FROM THE
APPROACHING FRONT WILL SPREAD INLAND AROUND 15Z. FROPA ON THE COAST
SHOULD BE AROUND 00Z...AND OVER PUGET SOUND AROUND 04Z. AT THE
SURFACE STRONG GUSTY SOUTHEAST WINDS WILL DEVELOP ALONG THE COAST
AND OVER PARTS OF THE NORTH INTERIOR ON FRIDAY.

CEILINGS THIS EVENING ARE GENERALLY VFR 4K-6K FT. LOCAL FOG WITH
VISIBILITIES 1/2SM ARE POSSIBLE TONIGHT. BY FRIDAY MORNING MOST
CEILINGS WILL FALL TO MVFR 2K-3K FT IN RAIN.

KSEA...DISCUSSION ABOVE APPLIES EXCEPT FOG IS UNLIKELY TONIGHT.
WINDS SOUTHEAST 4-8 KT. RAIN AND MVFR CONDITIONS WILL PREDOMINATE ON
FRIDAY. WINDS WILL RISE TO SOUTHERLY 8-12 KT IN THE AFTERNOON. CHB

&&

.MARINE...A STRONG FRONTAL SYSTEM WILL MOVE THROUGH THE AREA FRIDAY.
MODELS SHOW GALES OVER THE COASTAL WATERS STARTING FRIDAY AFTERNOON
AND OVER THE EAST ENTRANCE AND NORTH INLAND WATERS FRIDAY AFTERNOON
AND EVENING. SMALL CRAFT ADVISORY WINDS ARE EXPECTED OVER THE REST
OF THE WATERS. FROPA ALONG THE COAST SHOULD BE AROUND 00Z...THEN
AROUND 04Z OVER PUGET SOUND. A WESTERLY PUSH BEHIND THE FRONT SHOULD
PRODUCE SMALL CRAFT ADVISORY WEST WINDS THROUGH THE STRAIT AND OVER
THE NORTHERN INLAND WATERS.

WESTERLY FLOW ALOFT OVER THE NORTHEAST PACIFIC SATURDAY THROUGH
MONDAY WILL BRING SEVERAL WEAKER SURFACE TROUGHS ACROSS THE AREA.
CONFIDENCE IN THE TIMING AND STRENGTH OF EACH OF THESE TROUGHS IS
LOW...BUT THEY COULD PRODUCE SOLID ADVISORY LEVEL WINDS AND PERHAPS
SPOTTY GALES. SWELLS IN THE 15-20 FOOT RANGE ARE FORECAST TO REACH
THE COAST SUNDAY. CHB

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...WINTER WEATHER ADVISORY NORTH AND NORTH CENTRAL CASCADES.
     WIND ADVISORY NORTH AND CENTRAL COAST...THE SAN JUAN
     ISLANDS...AND WESTERN WHATCOM COUNTY.
PZ...GALE WARNING COAST...EAST ENTRANCE...NORTH INLAND WATERS.
     SMALL CRAFT ADVISORY ALL REMAINING WATERS.
     SMALL CRAFT ADVISORY FOR ROUGH GRAYS HARBOR BAR.

&&

$$

WWW.WEATHER.GOV/SEATTLE

YOU CAN SEE AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML





000
FXUS66 KPQR 210409
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
808 PM PST THU NOV 20 2014

.SYNOPSIS...THE PACIFIC NORTHWEST REMAINS IN BETWEEN TWO LOW PRESSURE
SYSTEMS...ONE OVER BRITISH COLUMBIA AND THE OTHER OVER CALIFORNIA. IN
BETWEEN THESE SYSTEMS THERE IS JUST ENOUGH MOISTURE FOR SOME AREAS OF
LIGHT RAIN...DRIZZLE...AND LOCALLY DENSE FOG. TEMPERATURES CONTINUE
TO HOVER NEAR FREEZING IN THE HOOD RIVER VALLEY...SO SOME VERY LIGHT
FREEZING RAIN OR DRIZZLE REMAIN POSSIBLE INTO FRIDAY MORNING. A
STRONG AND MOIST FRONT WILL BRING HEAVIER RAIN AND STRONG COASTAL
WINDS LATER FRIDAY INTO SATURDAY. COOLER AIR BEHIND THIS SYSTEM WILL
CAUSE THE SNOW LEVELS TO LOWER BELOW THE CASCADE PASSES EARLY
SATURDAY WHILE STRONG ONSHORE FLOW CONTINUES THROUGH THE WEEKEND. AS
A RESULT SNOW MAY BECOME HEAVY AT TIMES ALL THE WAY DOWN TO PASS
LEVEL THIS WEEKEND. ANOTHER SYSTEM IS LIKELY TO AFFECT THE REGION
EARLY NEXT WEEK...THEN PERHAPS SOME DRIER WEATHER BY MIDWEEK.

&&

.EVENING UPDATE...MAINLY COSMETIC CHANGES WERE MADE TO THE FORECAST
TO MAKE IT MORE CONSISTENT WITH CONDITIONS OCCURRING THIS EVENING.
FOG IS ALREADY DEVELOPING IN SOME AREAS...WITH VISIBILITY DOWN TO
1/4 MILE AT MCMINNVILLE AIRPORT WITHIN THE PAST COUPLE HOURS. MILD
AND MOIST PACIFIC AIR IS RUNNING OVER GROUND THAT IS BOTH MOIST AND
COOL... LIKELY AIDING THE FORMATION OF FOG DESPITE HIGHER CLOUD
COVER. AWAY FROM THE COLUMBIA GORGE...DEWPOINTS ARE IN THE 40S...AND
DEWPOINT DEPRESSIONS ARE ONLY A FEW DEGREES AT MOST. THEREFORE
INCREASED THE COVERAGE OF FOG. DECIDED AGAINST WIDESPREAD DENSE FOG
DUE TO THE HIGHER CLOUD COVER...BUT IF THESE CLOUDS CLEAR IT IS
LIKELY FOG WILL QUICKLY BECOME DENSE. LUCKILY MOST GUIDANCE SUGGESTS
A MID-LEVEL CLOUD DECK LINGERS THROUGHOUT THE NIGHT FOR MOST OF OUR
FORECAST AREA.

TEMPERATURES HOVER AROUND FREEZING IN THE HOOD RIVER VALLEY AND
NEARBY PORTIONS OF THE COLUMBIA GORGE THIS EVENING. THERE IS THE
POTENTIAL OF SOME LIGHT RAIN OR DRIZZLE TONIGHT AND FRIDAY MORNING.
THERE WILL NOT BE MUCH FORCING...THUS LITTLE IN THE WAY OF LIFT. 00Z
NAM BUFR AND UW 4KM WRF-GFS SOUNDINGS SUGGEST LITTLE TO NO SATURATION
IN THE COLUMN BELOW -5 DEG C...SO MOST PRECIPITATION TONIGHT SHOULD
BE IN THE FORM OF DRIZZLE. FREEZING DRIZZLE CAN STILL CAUSE SOME
TRAVEL HASSLES...BUT ANY IMPACTS SHOULD BE MINIMAL AND MOSTLY FELT IN
THE UPPER PORTIONS OF THE HOOD RIVER VALLEY.

WATER VAPOR AND INFRARED SATELLITE IMAGERY SHOW A STRONG PACIFIC
FRONTAL SYSTEM TAKING SHAPE OFFSHORE...WITH SOMEWHAT OF AN
ATMOSPHERIC RIVER ASSOCIATED WITH IT. PREVIOUS DISCUSSION BELOW
HANDLES IT WELL. DECIDED TO PUSH THE DECISION ON WHETHER OR NOT TO
UPGRADE THE HIGH WIND WATCH TO THE NEXT SHIFT...AS THERE IS STILL
SOME DISCREPANCY BETWEEN MODELS AS TO HOW STRONG THE COASTAL WINDS
WILL BE. 00Z NAM DOES HAVE A 60-65 KT COASTAL JET DOWN TO 900 MB
AHEAD OF THE FRONT FRI AFTERNOON...WHICH WOULD BE FAVORABLE FOR A
BEACHES/HEADLANDS HIGH WIND EVENT. HOWEVER THERE ARE A COUPLE
COMPLICATIONS...A SECONDARY SYSTEM BEHIND THE FRONT IS LIKELY TO
STRENGTHEN AND BECOME DOMINANT AS THE FIRST FRONT MOVES ONSHORE. THIS
COULD ROB SOME OF THE GRADIENT FROM THE COAST AND THEREFORE PREVENT
WINDS FROM BECOMING TOO STRONG WITH THE PRELIMINARY FRONT.
ALSO...DEPENDING ON THE TRACK OF THIS SECONDARY LOW...IT COULD BECOME
A BIT WINDY INLAND AS WELL. WILL HOLD FOR FULL SUITE OF 00Z GUIDANCE
BEFORE MAKING ANY LAND WARNING/ADVISORY DECISIONS.  WEAGLE

/PREV DISC ISSUED 315 PM PST THU NOV 20 2014/

.SHORT TERM...TONIGHT THROUGH SUNDAY...
TWO AREAS OF LOW PRES ASSOCIATED WITH A SPLIT UPPER LEVEL TROUGH ARE
MOVING ONSHORE TO THE NORTH AND SOUTH OF US THIS AFTERNOON. THE LOW
TO THE NORTH IS MOVING ONTO THE BRITISH COLUMBIA COAST...WHILE THE
OTHER SITS ALONG THE S OREGON AND N CALIFORNIA COAST AND WILL MOVE
ONSHORE TONIGHT. IN BETWEEN...WE ARE SEEING ONLY SOME LIGHT SHOWERS
OVER SW WASHINGTON AND NW OREGON AS THE HIGHLY STRETCHED UPPER LEVEL
TROF AXIS MOVES OVER THE REGION. ALSO...THE LATEST SURFACE
OBSERVATIONS SHOW THAT TEMPS THROUGH THE COLUMBIA RIVER GORGE AND
UPPER HOOD RIVER VALLEY HAVE WARMED ABOVE FREEZING JUST ABOUT
EVERYWHERE. SO THE THREAT OF FREEZING RAIN APPEARS TO BE OVER FOR
NOW. THE FCST MODELS INDICATE THAT A FEW WEAK SHOWERS WILL LINGER
INTO TONIGHT. BASED ON THE CLEARING SKIES OFFSHORE APPARENT ON
VISIBLE SATELLITE...THINK WE WILL SEE SOME SCATTERING OF THE CLOUD
COVER TONIGHT. THIS SHOULD ALLOW FOR SOME PATCHY FOG AND LOW STRATUS
TO FORM OVERNIGHT. OTHERWISE...EXPECT FAIRLY QUIET CONDITIONS
OVERNIGHT.

A STRONG 150+ KT JET STREAK WILL APPROACH THE PAC NW TOMORROW. THIS
WILL DRIVE A STRONG AND MOIST FRONTAL SYSTEM ONSHORE LATER TOMORROW
AND TOMORROW NIGHT. AMSU SATELLITE DERIVED IMAGERY SHOWS A REGION OF
SUBTROPICAL MOISTURE WELL OFFSHORE THAT WILL FEED INTO THIS SYSTEM.
THE FCST MODELS INDICATE THAT PWAT VALUES WILL BE AROUND 1.25 INCHES
ALONG THE COAST AS THE LEADING WARM FRONT MOVES ONSHORE. WE EXPECT A
BATCH OF HEAVY RAIN TO PUSH INLAND DURING THE LATE AFTERNOON AND
EVENING...WITH 1.5 TO 2 INCHES OF RAIN LIKELY FOR THE COAST...COAST
RANGE AND CASCADES OVER ABOUT A 12 HR PERIOD. THE INTERIOR LOWLANDS
WILL BE LOWER...CLOSER TO AROUND AN INCH. IT DOES NOT APPEAR THAT
RAINFALL TOTALS WILL BE ENOUGH TO CAUSE ANY FLOODING CONCERNS.

THIS SYSTEM WILL ALSO BRING A BURST OF STRONG WINDS ALONG THE COAST
DURING THE AFTERNOON AND EVENING. WILL CONTINUE WITH A HIGH WIND
WATCH FOR THE ENTIRE COAST FOR THE AFTERNOON AND EVENING. A CORE OF
60 KT WINDS AT 925 MB ARE BEING ADVERTISED BY THE 12Z NAM...GFS...
AND ECMWF RUNS. WILL CONFINE THE HIGHEST WINDS TO THE BEACHES AND
COASTAL HEADLANDS...WHERE GUSTS TO 65 MPH ARE CURRENTLY EXPECTED.
THE COASTAL COMMUNITIES SHOULD ALSO BE GUSTY...BUT WILL LIMIT WIND
GUSTS TO 50-55 MPH FOR NOW.

IT IS LOOKING LESS LIKELY THAT FREEZING RAIN IN THE COLUMBIA RIVER
GORGE AND UPPER HOOD RIVER VALLEY WILL BE A CONCERN WITH THIS SYSTEM
BASED ON THE WARMING TEMPS SEEN TODAY. TEMPS SHOULD FALL BACK TO JUST
BELOW FREEZING TONIGHT EAST OF THE CASCADES...AND THE FCST MODELS
CONTINUE TO INDICATE THAT LIGHT EASTERLY FLOW WILL CONTINUE THROUGH
THE INITIAL ONSET OF PRECIP TOMORROW. SO WILL KEEP A SLIGHT CHC OF
FREEZING RAIN AROUND HOOD RIVER AND IN THE HOOD RIVER VALLEY THROUGH
TOMORROW AFTERNOON. DO NOT THINK THERE WILL BE WIDESPREAD
ACCUMULATIONS...BUT SOME PATCHY SPOTS OF ICE ARE DEFINITELY POSSIBLE.
WINDS WILL SWITCH TO WESTERLY DURING THE EVENING...WHICH WILL WARM
THINGS UP CONSIDERABLY AND PUT AN END TO ANY ICE CONCERNS.

THE COLD FRONT WILL MOVE THROUGH THE REGION TOMORROW NIGHT WITH SNOW
LEVELS FALLING RAPIDLY OVERNIGHT INTO SAT MORNING. EXPECT SNOW LEVELS
TO REMAIN BELOW THE CASCADE PASSES THROUGH THE WEEKEND...WITH SHOWERS
CONTINUING IN DECENT OROGRAPHIC FLOW. SNOW WILL BE HEAVIER AT TIMES
AS WEAK IMPULSES MOVE THROUGH ALOFT. AT THIS TIME...IT APPEARS THE
PERIOD OF BEST SNOWFALL ACCUMULATION WILL BE OVERNIGHT SAT INTO EARLY
SUN. THIS PERIOD MAY END UP NEEDING A WINTER WEATHER ADVISORY AS WE
GET CLOSER IN TIME. PYLE


.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY. THE MORE WESTERLY OR
ZONAL FLOW THAT SETS UP OVER THE WEEKEND DURING THE LATTER PART OF
THE SHORT TERM PERIOD BEGINS TO BUCKLE A BIT IN THE EARLY PART OF
THE LONG TERM PERIOD WITH SOME FLAT RIDGING DEVELOPING OVER THE
NORTHEAST PACIFIC. HAVE DECIDED TO CONTINUE TO STICK MORE WITH A
DIRTY RIDGE SCENARIO OF THE ECMWF VS THE HIGHER AMPLITUDE RIDGING OF
THE OPERATIONAL GFS MODEL. CONFIDENCE DECREASES THROUGHOUT THE LONG
TERM PERIOD AS MODEL VARIABILITY INCREASES...THOUGH THE TREND IS
TOWARD DRIER DURING THE MIDDLE TO LATTER PARTS OF NEXT WEEK. TOLLESON

&&

.AVIATION...MIX OF MVFR AND VFR AS OF 04Z WITH MUCH OF THE COAST
IN MVFR CONDITIONS. ALREADY STARTING TO GET IFR AND LIFR VIS IN
THE INTERIOR VALLEYS. EXPECT THIS GENERAL MIX TO CONTINUE THROUGH
TONIGHT...WITH INCREASING IFR AND LIFR IN THE INLAND VALLEYS.
AREAS NEAR THE COLUMBIA GORGE WILL STAY VFR WITH DUE TO EAST WIND.
RAIN TO DEVELOP ALONG THE COAST 12-15Z FRI AND THEN INTENSIFY
AFTER 20Z. THIS WILL BRING WIDESPREAD IFR AND LOW-END MVFR
CONDITIONS TO THE COAST...ALONG WITH INCREASING WIND. RAIN SPREADS
INLAND DURING THE DAY FRI...WITH MAINLY MVFR OR WORSE CONDITIONS
THROUGH EARLY EVENING.

KPDX AND APPROACHES...VFR TO PREVAIL THROUGH FRI MORNING...
ALTHOUGH AREAS OF IFR EXPECTED TO DEVELOP OVER THE WRN APPROACHES
TONIGHT AND PERSIST THROUGH THE MORNING. INCREASING RAIN AFTER 18Z
FRI RESULTING IN MAINLY MVFR CONDITIONS THROUGH THE EARLY EVENING.
LLWS POSSIBLE AT KPDX AND ERN APPROACHES FRI AFTERNOON WITH E TO
SE SURFACE AND 30-40 KT S-SW WIND AT FL 020 BASED ON MODEL
SOUNDINGS. WEISHAAR

&&

.MARINE...WIND SPEEDS HAVE EASED A BIT THIS EVENING...BUT STILL
HOVERING AT OR CLOSE TO SMALL CRAFT ADVISORY CRITERIA. WILL
MAINTAIN THE CURRENT ADVISORY FOR WIND THROUGH 18Z FRI. STRONG
GALES EXPECTED TO DEVELOP AFTER 18Z FRI...WITH COASTAL JET
ENHANCEMENT POSSIBLE FRI AFTERNOON THROUGH EARLY EVENING. SHOULD
THIS OCCUR...LOCALIZED 40-45 KT SUSTAINED WIND WITH GUSTS 50-55 KT
WOULD BE POSSIBLE WITHIN ABOUT 10 NM FROM SHORELINE. LATEST NAM
RUN NOT QUITE AS STRONG...KEEPING THE TIGHTEST GRADIENT OVER THE
SRN OREGON WATERS. 00Z GFS MUCH STRONGER WITH BOUNDARY LAYER WIND
SPEEDS FRI AFTERNOON. DUE TO THIS MODEL DISCREPANCY WILL LEAVE
CURRENT WARNINGS AND THE STORM WATCH AS IS FOR NOW. WIND SPEEDS
SUBSIDE FRI NIGHT AND SATURDAY.

SEAS AT 10 FT OR JUST UNDER AS OF 04Z. SEAS FORECAST TO BE
PRIMARILY 9 FT THROUGH MIDNIGHT THEN EDGE ABOVE 10 FT LATE
TONIGHT. HAVE OPTED TO ISSUE A SMALL CRAFT ADVISORY FOR HAZARDOUS
SEAS STARTING AT 08Z. SEAS QUICKLY BUILD FRI WITH THE STRONG GALE
OR NEAR STORM-FORCE WIND CONDITIONS. COULD GET CLOSE TO 20 FEET
LATE FRI AFTERNOON THROUGH THE EVENING...BUT WITH A LARGE WIND-
WAVE COMPONENT. WAVE HEIGHTS DROP OFF FAIRLY FRI NIGHT BEHIND THE
COLD FRONT AND AS WIND SPEEDS WEAKEN. HOWEVER...SEAS LOOK TO
REMAIN ABOVE 10 FT THROUGH THIS WEEKEND. WEISHAAR

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...HIGH WIND WATCH FROM FRIDAY MORNING THROUGH FRIDAY EVENING FOR
     CENTRAL OREGON COAST-NORTH OREGON COAST.

WA...HIGH WIND WATCH FROM FRIDAY MORNING THROUGH FRIDAY EVENING FOR
     SOUTH WASHINGTON COAST.

PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 10 AM PST FRIDAY FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     GALE WARNING FROM 10 AM TO 10 PM PST FRIDAY FOR COASTAL WATERS
     FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM MIDNIGHT TONIGHT
     TO 10 AM PST FRIDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA
     TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM MIDNIGHT
     TONIGHT TO 6 AM PST FRIDAY.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM NOON TO
     10 PM PST FRIDAY.

     STORM WATCH FROM FRIDAY AFTERNOON THROUGH FRIDAY EVENING FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR
     OUT 10 NM-COASTAL WATERS FROM CASCADE HEAD TO FLORENCE OR
     OUT 10 NM.

&&

$$

INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND

THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.




000
FXUS66 KPQR 210409
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
808 PM PST THU NOV 20 2014

.SYNOPSIS...THE PACIFIC NORTHWEST REMAINS IN BETWEEN TWO LOW PRESSURE
SYSTEMS...ONE OVER BRITISH COLUMBIA AND THE OTHER OVER CALIFORNIA. IN
BETWEEN THESE SYSTEMS THERE IS JUST ENOUGH MOISTURE FOR SOME AREAS OF
LIGHT RAIN...DRIZZLE...AND LOCALLY DENSE FOG. TEMPERATURES CONTINUE
TO HOVER NEAR FREEZING IN THE HOOD RIVER VALLEY...SO SOME VERY LIGHT
FREEZING RAIN OR DRIZZLE REMAIN POSSIBLE INTO FRIDAY MORNING. A
STRONG AND MOIST FRONT WILL BRING HEAVIER RAIN AND STRONG COASTAL
WINDS LATER FRIDAY INTO SATURDAY. COOLER AIR BEHIND THIS SYSTEM WILL
CAUSE THE SNOW LEVELS TO LOWER BELOW THE CASCADE PASSES EARLY
SATURDAY WHILE STRONG ONSHORE FLOW CONTINUES THROUGH THE WEEKEND. AS
A RESULT SNOW MAY BECOME HEAVY AT TIMES ALL THE WAY DOWN TO PASS
LEVEL THIS WEEKEND. ANOTHER SYSTEM IS LIKELY TO AFFECT THE REGION
EARLY NEXT WEEK...THEN PERHAPS SOME DRIER WEATHER BY MIDWEEK.

&&

.EVENING UPDATE...MAINLY COSMETIC CHANGES WERE MADE TO THE FORECAST
TO MAKE IT MORE CONSISTENT WITH CONDITIONS OCCURRING THIS EVENING.
FOG IS ALREADY DEVELOPING IN SOME AREAS...WITH VISIBILITY DOWN TO
1/4 MILE AT MCMINNVILLE AIRPORT WITHIN THE PAST COUPLE HOURS. MILD
AND MOIST PACIFIC AIR IS RUNNING OVER GROUND THAT IS BOTH MOIST AND
COOL... LIKELY AIDING THE FORMATION OF FOG DESPITE HIGHER CLOUD
COVER. AWAY FROM THE COLUMBIA GORGE...DEWPOINTS ARE IN THE 40S...AND
DEWPOINT DEPRESSIONS ARE ONLY A FEW DEGREES AT MOST. THEREFORE
INCREASED THE COVERAGE OF FOG. DECIDED AGAINST WIDESPREAD DENSE FOG
DUE TO THE HIGHER CLOUD COVER...BUT IF THESE CLOUDS CLEAR IT IS
LIKELY FOG WILL QUICKLY BECOME DENSE. LUCKILY MOST GUIDANCE SUGGESTS
A MID-LEVEL CLOUD DECK LINGERS THROUGHOUT THE NIGHT FOR MOST OF OUR
FORECAST AREA.

TEMPERATURES HOVER AROUND FREEZING IN THE HOOD RIVER VALLEY AND
NEARBY PORTIONS OF THE COLUMBIA GORGE THIS EVENING. THERE IS THE
POTENTIAL OF SOME LIGHT RAIN OR DRIZZLE TONIGHT AND FRIDAY MORNING.
THERE WILL NOT BE MUCH FORCING...THUS LITTLE IN THE WAY OF LIFT. 00Z
NAM BUFR AND UW 4KM WRF-GFS SOUNDINGS SUGGEST LITTLE TO NO SATURATION
IN THE COLUMN BELOW -5 DEG C...SO MOST PRECIPITATION TONIGHT SHOULD
BE IN THE FORM OF DRIZZLE. FREEZING DRIZZLE CAN STILL CAUSE SOME
TRAVEL HASSLES...BUT ANY IMPACTS SHOULD BE MINIMAL AND MOSTLY FELT IN
THE UPPER PORTIONS OF THE HOOD RIVER VALLEY.

WATER VAPOR AND INFRARED SATELLITE IMAGERY SHOW A STRONG PACIFIC
FRONTAL SYSTEM TAKING SHAPE OFFSHORE...WITH SOMEWHAT OF AN
ATMOSPHERIC RIVER ASSOCIATED WITH IT. PREVIOUS DISCUSSION BELOW
HANDLES IT WELL. DECIDED TO PUSH THE DECISION ON WHETHER OR NOT TO
UPGRADE THE HIGH WIND WATCH TO THE NEXT SHIFT...AS THERE IS STILL
SOME DISCREPANCY BETWEEN MODELS AS TO HOW STRONG THE COASTAL WINDS
WILL BE. 00Z NAM DOES HAVE A 60-65 KT COASTAL JET DOWN TO 900 MB
AHEAD OF THE FRONT FRI AFTERNOON...WHICH WOULD BE FAVORABLE FOR A
BEACHES/HEADLANDS HIGH WIND EVENT. HOWEVER THERE ARE A COUPLE
COMPLICATIONS...A SECONDARY SYSTEM BEHIND THE FRONT IS LIKELY TO
STRENGTHEN AND BECOME DOMINANT AS THE FIRST FRONT MOVES ONSHORE. THIS
COULD ROB SOME OF THE GRADIENT FROM THE COAST AND THEREFORE PREVENT
WINDS FROM BECOMING TOO STRONG WITH THE PRELIMINARY FRONT.
ALSO...DEPENDING ON THE TRACK OF THIS SECONDARY LOW...IT COULD BECOME
A BIT WINDY INLAND AS WELL. WILL HOLD FOR FULL SUITE OF 00Z GUIDANCE
BEFORE MAKING ANY LAND WARNING/ADVISORY DECISIONS.  WEAGLE

/PREV DISC ISSUED 315 PM PST THU NOV 20 2014/

.SHORT TERM...TONIGHT THROUGH SUNDAY...
TWO AREAS OF LOW PRES ASSOCIATED WITH A SPLIT UPPER LEVEL TROUGH ARE
MOVING ONSHORE TO THE NORTH AND SOUTH OF US THIS AFTERNOON. THE LOW
TO THE NORTH IS MOVING ONTO THE BRITISH COLUMBIA COAST...WHILE THE
OTHER SITS ALONG THE S OREGON AND N CALIFORNIA COAST AND WILL MOVE
ONSHORE TONIGHT. IN BETWEEN...WE ARE SEEING ONLY SOME LIGHT SHOWERS
OVER SW WASHINGTON AND NW OREGON AS THE HIGHLY STRETCHED UPPER LEVEL
TROF AXIS MOVES OVER THE REGION. ALSO...THE LATEST SURFACE
OBSERVATIONS SHOW THAT TEMPS THROUGH THE COLUMBIA RIVER GORGE AND
UPPER HOOD RIVER VALLEY HAVE WARMED ABOVE FREEZING JUST ABOUT
EVERYWHERE. SO THE THREAT OF FREEZING RAIN APPEARS TO BE OVER FOR
NOW. THE FCST MODELS INDICATE THAT A FEW WEAK SHOWERS WILL LINGER
INTO TONIGHT. BASED ON THE CLEARING SKIES OFFSHORE APPARENT ON
VISIBLE SATELLITE...THINK WE WILL SEE SOME SCATTERING OF THE CLOUD
COVER TONIGHT. THIS SHOULD ALLOW FOR SOME PATCHY FOG AND LOW STRATUS
TO FORM OVERNIGHT. OTHERWISE...EXPECT FAIRLY QUIET CONDITIONS
OVERNIGHT.

A STRONG 150+ KT JET STREAK WILL APPROACH THE PAC NW TOMORROW. THIS
WILL DRIVE A STRONG AND MOIST FRONTAL SYSTEM ONSHORE LATER TOMORROW
AND TOMORROW NIGHT. AMSU SATELLITE DERIVED IMAGERY SHOWS A REGION OF
SUBTROPICAL MOISTURE WELL OFFSHORE THAT WILL FEED INTO THIS SYSTEM.
THE FCST MODELS INDICATE THAT PWAT VALUES WILL BE AROUND 1.25 INCHES
ALONG THE COAST AS THE LEADING WARM FRONT MOVES ONSHORE. WE EXPECT A
BATCH OF HEAVY RAIN TO PUSH INLAND DURING THE LATE AFTERNOON AND
EVENING...WITH 1.5 TO 2 INCHES OF RAIN LIKELY FOR THE COAST...COAST
RANGE AND CASCADES OVER ABOUT A 12 HR PERIOD. THE INTERIOR LOWLANDS
WILL BE LOWER...CLOSER TO AROUND AN INCH. IT DOES NOT APPEAR THAT
RAINFALL TOTALS WILL BE ENOUGH TO CAUSE ANY FLOODING CONCERNS.

THIS SYSTEM WILL ALSO BRING A BURST OF STRONG WINDS ALONG THE COAST
DURING THE AFTERNOON AND EVENING. WILL CONTINUE WITH A HIGH WIND
WATCH FOR THE ENTIRE COAST FOR THE AFTERNOON AND EVENING. A CORE OF
60 KT WINDS AT 925 MB ARE BEING ADVERTISED BY THE 12Z NAM...GFS...
AND ECMWF RUNS. WILL CONFINE THE HIGHEST WINDS TO THE BEACHES AND
COASTAL HEADLANDS...WHERE GUSTS TO 65 MPH ARE CURRENTLY EXPECTED.
THE COASTAL COMMUNITIES SHOULD ALSO BE GUSTY...BUT WILL LIMIT WIND
GUSTS TO 50-55 MPH FOR NOW.

IT IS LOOKING LESS LIKELY THAT FREEZING RAIN IN THE COLUMBIA RIVER
GORGE AND UPPER HOOD RIVER VALLEY WILL BE A CONCERN WITH THIS SYSTEM
BASED ON THE WARMING TEMPS SEEN TODAY. TEMPS SHOULD FALL BACK TO JUST
BELOW FREEZING TONIGHT EAST OF THE CASCADES...AND THE FCST MODELS
CONTINUE TO INDICATE THAT LIGHT EASTERLY FLOW WILL CONTINUE THROUGH
THE INITIAL ONSET OF PRECIP TOMORROW. SO WILL KEEP A SLIGHT CHC OF
FREEZING RAIN AROUND HOOD RIVER AND IN THE HOOD RIVER VALLEY THROUGH
TOMORROW AFTERNOON. DO NOT THINK THERE WILL BE WIDESPREAD
ACCUMULATIONS...BUT SOME PATCHY SPOTS OF ICE ARE DEFINITELY POSSIBLE.
WINDS WILL SWITCH TO WESTERLY DURING THE EVENING...WHICH WILL WARM
THINGS UP CONSIDERABLY AND PUT AN END TO ANY ICE CONCERNS.

THE COLD FRONT WILL MOVE THROUGH THE REGION TOMORROW NIGHT WITH SNOW
LEVELS FALLING RAPIDLY OVERNIGHT INTO SAT MORNING. EXPECT SNOW LEVELS
TO REMAIN BELOW THE CASCADE PASSES THROUGH THE WEEKEND...WITH SHOWERS
CONTINUING IN DECENT OROGRAPHIC FLOW. SNOW WILL BE HEAVIER AT TIMES
AS WEAK IMPULSES MOVE THROUGH ALOFT. AT THIS TIME...IT APPEARS THE
PERIOD OF BEST SNOWFALL ACCUMULATION WILL BE OVERNIGHT SAT INTO EARLY
SUN. THIS PERIOD MAY END UP NEEDING A WINTER WEATHER ADVISORY AS WE
GET CLOSER IN TIME. PYLE


.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY. THE MORE WESTERLY OR
ZONAL FLOW THAT SETS UP OVER THE WEEKEND DURING THE LATTER PART OF
THE SHORT TERM PERIOD BEGINS TO BUCKLE A BIT IN THE EARLY PART OF
THE LONG TERM PERIOD WITH SOME FLAT RIDGING DEVELOPING OVER THE
NORTHEAST PACIFIC. HAVE DECIDED TO CONTINUE TO STICK MORE WITH A
DIRTY RIDGE SCENARIO OF THE ECMWF VS THE HIGHER AMPLITUDE RIDGING OF
THE OPERATIONAL GFS MODEL. CONFIDENCE DECREASES THROUGHOUT THE LONG
TERM PERIOD AS MODEL VARIABILITY INCREASES...THOUGH THE TREND IS
TOWARD DRIER DURING THE MIDDLE TO LATTER PARTS OF NEXT WEEK. TOLLESON

&&

.AVIATION...MIX OF MVFR AND VFR AS OF 04Z WITH MUCH OF THE COAST
IN MVFR CONDITIONS. ALREADY STARTING TO GET IFR AND LIFR VIS IN
THE INTERIOR VALLEYS. EXPECT THIS GENERAL MIX TO CONTINUE THROUGH
TONIGHT...WITH INCREASING IFR AND LIFR IN THE INLAND VALLEYS.
AREAS NEAR THE COLUMBIA GORGE WILL STAY VFR WITH DUE TO EAST WIND.
RAIN TO DEVELOP ALONG THE COAST 12-15Z FRI AND THEN INTENSIFY
AFTER 20Z. THIS WILL BRING WIDESPREAD IFR AND LOW-END MVFR
CONDITIONS TO THE COAST...ALONG WITH INCREASING WIND. RAIN SPREADS
INLAND DURING THE DAY FRI...WITH MAINLY MVFR OR WORSE CONDITIONS
THROUGH EARLY EVENING.

KPDX AND APPROACHES...VFR TO PREVAIL THROUGH FRI MORNING...
ALTHOUGH AREAS OF IFR EXPECTED TO DEVELOP OVER THE WRN APPROACHES
TONIGHT AND PERSIST THROUGH THE MORNING. INCREASING RAIN AFTER 18Z
FRI RESULTING IN MAINLY MVFR CONDITIONS THROUGH THE EARLY EVENING.
LLWS POSSIBLE AT KPDX AND ERN APPROACHES FRI AFTERNOON WITH E TO
SE SURFACE AND 30-40 KT S-SW WIND AT FL 020 BASED ON MODEL
SOUNDINGS. WEISHAAR

&&

.MARINE...WIND SPEEDS HAVE EASED A BIT THIS EVENING...BUT STILL
HOVERING AT OR CLOSE TO SMALL CRAFT ADVISORY CRITERIA. WILL
MAINTAIN THE CURRENT ADVISORY FOR WIND THROUGH 18Z FRI. STRONG
GALES EXPECTED TO DEVELOP AFTER 18Z FRI...WITH COASTAL JET
ENHANCEMENT POSSIBLE FRI AFTERNOON THROUGH EARLY EVENING. SHOULD
THIS OCCUR...LOCALIZED 40-45 KT SUSTAINED WIND WITH GUSTS 50-55 KT
WOULD BE POSSIBLE WITHIN ABOUT 10 NM FROM SHORELINE. LATEST NAM
RUN NOT QUITE AS STRONG...KEEPING THE TIGHTEST GRADIENT OVER THE
SRN OREGON WATERS. 00Z GFS MUCH STRONGER WITH BOUNDARY LAYER WIND
SPEEDS FRI AFTERNOON. DUE TO THIS MODEL DISCREPANCY WILL LEAVE
CURRENT WARNINGS AND THE STORM WATCH AS IS FOR NOW. WIND SPEEDS
SUBSIDE FRI NIGHT AND SATURDAY.

SEAS AT 10 FT OR JUST UNDER AS OF 04Z. SEAS FORECAST TO BE
PRIMARILY 9 FT THROUGH MIDNIGHT THEN EDGE ABOVE 10 FT LATE
TONIGHT. HAVE OPTED TO ISSUE A SMALL CRAFT ADVISORY FOR HAZARDOUS
SEAS STARTING AT 08Z. SEAS QUICKLY BUILD FRI WITH THE STRONG GALE
OR NEAR STORM-FORCE WIND CONDITIONS. COULD GET CLOSE TO 20 FEET
LATE FRI AFTERNOON THROUGH THE EVENING...BUT WITH A LARGE WIND-
WAVE COMPONENT. WAVE HEIGHTS DROP OFF FAIRLY FRI NIGHT BEHIND THE
COLD FRONT AND AS WIND SPEEDS WEAKEN. HOWEVER...SEAS LOOK TO
REMAIN ABOVE 10 FT THROUGH THIS WEEKEND. WEISHAAR

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...HIGH WIND WATCH FROM FRIDAY MORNING THROUGH FRIDAY EVENING FOR
     CENTRAL OREGON COAST-NORTH OREGON COAST.

WA...HIGH WIND WATCH FROM FRIDAY MORNING THROUGH FRIDAY EVENING FOR
     SOUTH WASHINGTON COAST.

PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 10 AM PST FRIDAY FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     GALE WARNING FROM 10 AM TO 10 PM PST FRIDAY FOR COASTAL WATERS
     FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM MIDNIGHT TONIGHT
     TO 10 AM PST FRIDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA
     TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM MIDNIGHT
     TONIGHT TO 6 AM PST FRIDAY.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM NOON TO
     10 PM PST FRIDAY.

     STORM WATCH FROM FRIDAY AFTERNOON THROUGH FRIDAY EVENING FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR
     OUT 10 NM-COASTAL WATERS FROM CASCADE HEAD TO FLORENCE OR
     OUT 10 NM.

&&

$$

INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND

THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.



000
FXUS66 KSEW 210027
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
425 PM PST THU NOV 20 2014

.SYNOPSIS...THE AREA WILL BE BETWEEN SYSTEMS TONIGHT. A PACIFIC
STORM WILL IMPACT THE REGION ON FRIDAY AND FRIDAY NIGHT WITH LOCALLY
HEAVY RAIN AND GUSTY WINDS...ALONG WITH DECENT SNOWFALL IN THE
CASCADES FROM STEVENS PASS NORTHWARD. THE WEATHER PATTERN WILL
REMAIN WET AND UNSETTLED THIS WEEKEND WITH ANOTHER WEATHER SYSTEM
IMPACTING THE AREA ON SUNDAY. MUCH UNCERTAINTY EXISTS IN THE
FORECAST FROM MONDAY ONWARD.

&&

.SHORT TERM...THE RADAR IS SHOWING SOME SHOWERS CONTINUING...IN
AGREEMENT WITH THE MOST RECENT MODEL RUNS...SO I HAVE ADDED SHOWERS
INTO THE FORECAST FOR THIS EVENING. ANY REMAINING SHOWERS SHOULD
TAPER OFF OVERNIGHT.

ON FRIDAY AND FRIDAY NIGHT...A RELATIVELY STRONG FRONTAL SYSTEM
STEMMING FROM A DEEP LOW OVER THE ALEUTIAN ISLANDS WILL MOVE THROUGH
WESTERN WASHINGTON. THE FRONT WILL REACH THE COAST IN THE EARLY
EVENING AND MOVE INLAND OVERNIGHT. WIND ADVISORIES HAVE BEEN ISSUED
FOR THE NORTH AND CENTRAL COAST AS WELL AS THE SAN JUANS AND WESTERN
WHATCOM COUNTY. WINDS AHEAD OF THE FRONT WILL BE FROM THE SOUTH AND
THEN THE WINDS WILL SWITCH AROUND TO THE WEST AND WEAKEN SLIGHTLY AS
THE FRONT MOVES THROUGH.

A WINTER WEATHER ADVISORY FOR SNOW HAS BEEN ISSUED FOR THE CASCADES
OF KING COUNTY NORTHWARDS FOR ELEVATIONS ABOVE 4000 FEET...AS THERE
WILL BE QUITE A BIT OF PRECIPITATION WITH THE FRONT AND SNOW LEVELS
IN THE NORTH CASCADES WILL BE FAIRLY LOW. HIGHER SURFACE PRESSURE
EAST OF THE CASCADES WILL KEEP COOLER AIR FROM EASTERN WASHINGTON
FLOWING THROUGH THE PASSES AT LOWER LEVELS...LOWERING THE SNOW LEVEL
TO GROUND LEVEL AT STEVENS. NEARLY ALL OF THE PRECIPITATION AT
STEVENS ON FRIDAY AND FRIDAY NIGHT IS LIKELY TO BE IN THE FORM OF
SNOW. HOWEVER...SINCE THE MOUNT BAKER SKI AREA IS FURTHER WEST AND
IS NOT IMPACTED AS MUCH BY AIR FLOWING OVER FROM EASTERN
WASHINGTON...IT MAY SEE A MIX OF RAIN AND SNOW ON FRIDAY BEFORE
SWITCHING OVER TO SNOW LATER FRIDAY AS THE SNOW LEVELS DROP A BIT.

ON SATURDAY AND SATURDAY...MOISTURE BEHIND THE FRONT WILL CONTINUE
TO IMPACT THE AREA...SO I HAVE KEPT A GOOD CHANCE OF PRECIPITATION
IN THE FORECAST. SNOW LEVELS WILL LIKELY DROP TO BELOW 3000 FEET
ACROSS WESTERN WASHINGTON...SO CONTINUING SNOW AT STEVENS AND MOUNT
BAKER...AS WELL AS SNOWFALL AT WHITE PASS...HURRICANE RIDGE...AND MT
RAINIER...IS LIKELY. ACCUMULATIONS MAY APPROACH WINTER WEATHER
ADVISORY CRITERIA IN SOME AREAS.

ON SUNDAY...A SHORTWAVE TROUGH WILL IMPACT THE AREA AND BRING MORE
RAIN AND SNOW TO THE MOUNTAINS. SNOW LEVELS WILL REMAIN BELOW 3000
FEET SO A GOOD AMOUNT OF SNOW ACCUMULATION IS LIKELY IN THE
MOUNTAINS. JSMITH

&&

.LONG TERM...MONDAY THROUGH WEDNESDAY...BOTH THE GFS AND ECMWF SHOW
MOISTURE BEING TRANSPORTED TO THE PACIFIC NW VIA THE JET
STREAM...HOWEVER THE GFS HAS THE MOISTURE HITTING SW BC FOR THE MOST
PART AND US STAYING DRY...WHEREAS THE ECMWF HAS A WETTER SOLUTION
FOR US WITH THE MOISTURE HITTING US DIRECTLY. THEREFORE MUCH
UNCERTAINTY EXISTS IN THE FORECAST. THURSDAY LOOKS DRY WITH A RIDGE
BUILDING IN ON BOTH MODELS...BUT IT IS TOO EARLY TO TELL WITH MUCH
CERTAINTY. JSMITH

&&

.HYDROLOGY...RIVER FLOODING IS NOT EXPECTED THE NEXT 7 DAYS.

&&

.AVIATION...WEST FLOW ALOFT WILL INCREASE TONIGHT AS A WEAK UPPER
LEVEL TROUGH MOVES E OF THE AREA AND A STRONG FRONTAL SYSTEM
APPROACHES THE COAST. THE AIR MASS IS ALREADY MOIST AND STABLE FROM
THE TROUGH...WITH SPOTTY SHOWERS AND CIGS MAINLY BKN-OVC030-060.
RAIN FROM THE APPROACHING FRONT WILL SPREAD INLAND AROUND 15Z. FROPA
ON THE COAST SHOULD BE AROUND 00Z...AND OVER PUGET SOUND AROUND 04Z.
GUSTY S-SE WINDS ARE EXPECTED TO DEVELOP ALONG THE COAST AND OVER
PARTS OF THE NORTH INTERIOR ON FRIDAY. CIGS AND VISIBILITY WILL
LOWER TO MVFR AFTER 15Z.

KSEA...THE MOIST AIR MASS OVER THE REGION WILL KEEP CIGS IN THE
BKN-OVC025-040 RANGE THROUGH 08Z. WINDS WILL REMAIN S 5-10 KT. RAIN
AND MVFR CONDITIONS WILL PREDOMINATE ON FRIDAY. KAM

&&

.MARINE...THE NEXT FRONTAL SYSTEM OVER THE NE PACIFIC WAS ALONG 135W
AT 22Z/2 PM. IT WILL APPROACH THE REGION TONIGHT THEN MOVE
ACROSS THE AREA FRIDAY/FRIDAY EVENING. MODELS REMAIN FAIRLY
CONSISTENT IN SHOWING GALES OVER THE COASTAL WATERS STARTING FRIDAY
AFTERNOON AND OVER THE EAST ENTRANCE AND NORTH INLAND WATERS MAINLY
FRIDAY AFTERNOON AND EVENING. SMALL CRAFT ADVISORY WINDS ARE
EXPECTED OVER THE REMAINING WATERS. FROPA ALONG THE COAST SHOULD BE
AROUND 00Z...THEN AROUND 04Z OVER PUGET SOUND. A WESTERLY PUSH
BEHIND THE FRONT SHOULD PRODUCE SCA WINDS THROUGH THE STRAIT AND
OVER THE N INLAND WATERS.

WESTERLY FLOW ALOFT OVER THE NORTHEAST PACIFIC SATURDAY THROUGH
MONDAY WILL BRING SEVERAL WEAKER SURFACE TROUGHS ACROSS THE AREA.
CONFIDENCE IN THE TIMING AND STRENGTH OF EACH OF THESE TROUGHS IS
LOW...BUT THEY COULD PRODUCE SOLID SCA WINDS AND PERHAPS SPOTTY
GALES. SWELLS IN THE 15-20 FOOT RANGE ARE FORECAST TO REACH THE
COAST SUNDAY. KAM

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...WINTER WEATHER ADVISORY NORTH AND NORTH CENTRAL CASCADES.
     WIND ADVISORY NORTH AND CENTRAL COAST...THE SAN JUAN
     ISLANDS...AND WESTERN WHATCOM COUNTY.
PZ...GALE WARNING COAST...EAST ENTRANCE...NORTH INLAND WATERS.
     SMALL CRAFT ADVISORY ALL REMAINING WATERS.
     SMALL CRAFT ADVISORY FOR ROUGH GRAYS HARBOR BAR.

&&

$$

WWW.WEATHER.GOV/SEATTLE

YOU CAN SEE AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML














000
FXUS66 KOTX 202345
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
345 PM PST THU NOV 20 2014

.SYNOPSIS...
A relatively quiet and cool overnight period with a few snow
showers over the north will give way to a sharp deterioration in
the weather on Friday as a strong and moist Pacific storm brings
valley rain and mountain snow Friday night followed by very windy
conditions on Saturday. An active and periodically wet weather
regime will continue through the next week.

&&

.DISCUSSION...
Tonight...A rather mushy but somewhat benign night is in store
fro the region. Satellite and radar indicate the exiting storm
band that brought light snow to the region on track to move off
to the east early this evening. Meanwhile the next minor trough is
diving into California with a weak northern branch wave scuttling
into southern British Columbia. Models suggest a weak and
shearing wave will exist between these two dynamic centers and
will transit the region tonight...but the weakening nature of this
system should bring little beyond a few snow showers concentrated
over the northeastern zones late tonight. Once again fog and the
potential fro some freezing drizzle will exist in the deep basin
where stubborn arctic air is pooling in these low elevations.

Friday through Saturday...Latest models are in good agreement and
consistent with bringing a very moist and very dynamic wave
through the region during this period. A strong warm front will
make short work of the leftover and now modified arctic air over
the eastern half of the forecast area with snow levels expected to
rise to the 4000 foot region. In the west the cold air will be
slower to scrub and snow levels will stay low through much of this
event...perhaps all of it in the northern Cascade valleys and the
Okanogan valley. Snow levels will rise...but not as aggressively
over the southern portions of the deep basin...leading to the
likelihood of at least minimal warning criteria accumulating snow
on the Waterville Plateau. The southern valleys such as the
Wenatchee River valley will see some snow but amounts will be
overall fairly light. The Cascade mountains above 3000 to 4000
feet will get hammered with snow with a 12 hour period of moist
isentropic lift augmented by upslope southeasterly low level flow.
All the existing Winter Storm Watches will be upgraded to warnings
with the afternoon package...as well as adding the Okanogan and
Waterville Plateau to the highlight mix.

Beginning Friday morning the isentropic moistening process
will promote increasing clouds...with light snow beginning over
the northern zones in the early afternoon. By Friday evening an
almost universal field of valley rain and mountain snow will
envelop the region...except for the aforementioned north
Cascades/Okanogan where snow will continue as the dominant
meteor.

A strong cold front will rip through the region Saturday morning
largely ending precipitation in the Cascades lee but promoting
enhanced upslope snow showers into the Idaho Panhandle mountains.
The big story on Saturday will be very windy conditions especially
over the eastern basin exposed terrain with gust potential picked
off of model sounding mixed layers up to 45 or 50 mph. Saturday
will be a well mixed day with much milder temperatures than we
have grown accustomed to. /Fugazzi

Saturday Night through Monday Night: In the wake of Saturday`s
cold front, the breezy afternoon winds will gradually subside
overnight. Don`t see a great push of dry air behind this front. We
should have clearing skies in most places. This will allow
temperatures to drop sharply, especially in the northern valleys.
Then fog and stratus will form overnight and persist into Sunday
morning. The northwesterly flow is very unstable so the Panhandle
mountains will continue to pile up snow Saturday night.

By Sunday, another Pacific system will quickly clip across the
area. Due to the strong westerly flow, the Cascades and Panhandle
will be favored with this system. Spokane metro area could see
a little snow Sunday morning but will change to rain in the
afternoon.

Confidence is much lower for Monday`s event. The models really
diverge from each other on track and timing so I have about as
much chance of being wrong as right on the forecast. Went with
likely wording for the Cascades/Panhandle and chance wording
elsewhere. As usual, Highway 2/I-90 will be the dividing line
between rain and snow.  RJ

Tuesday through Thanksgiving: This portion of the forecast is
quite complicated, which is important because it envelops one of
the busiest travels days of the year. Unfortunately, the models
are having a hard time coming to some agreement, which makes this,
unfortunately, a low confidence forecast. There is some higher
confidence for Tuesday, as a shortwave traversed the region in
northwest flow. This will bring better chances of precipitation to
the Cascades, and the higher terrain of northeast Washington and
the Idaho Panhandle. It was happens after Tuesday where things get
all mucked up. The Euro model has stuck to its guns, carving out a
larger trough over much of the US, keeping the Inland Northwest on
the western edge of the cold air mass. The GFS keeps any
influence of the cold air mass well to the east, instead building
a ridge of high pressure over the region. This ridge is more
amplified than it`s previous solutions. So, all in all, we didn`t
stray much from the previous forecasts, which weighted towards the
more consistent solution (colder). While this would bring snow
levels into the valleys, the north-northwesterly flow does not
look like it will have a ton of moisture to work with. Lots of
fine-tuning will be made to this portion of the forecast for sure.
ty

&&

.AVIATION...
00Z TAFS: MVFR Ceilings and vis will be common over the region
through tonight as a moist boundary layer and light winds exists
under a strong low level inversion...with IFR conditions likely
redeveloping mainly at the KMWH and KGEG vicinity TAF sites
overnight. On Friday an approaching Pacific storm system will
spread thickening clouds over the region as a warm front develops.
MVFR ceilings will probably remain common across the Columbia
basin except fro KLWS where VFR conditions are expected. Light
snow or rain may begin at the KEAT TAF site during the afternoon.
/MJF


&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        28  37  36  43  30  40 /  20  30 100  30  20  60
Coeur d`Alene  30  39  36  42  31  39 /  30  50 100  50  30  70
Pullman        29  41  36  43  34  42 /  10  10 100  70  40  60
Lewiston       32  44  40  48  36  47 /  10  10 100  70  30  50
Colville       25  37  34  44  20  38 /  30  70 100  50  10  60
Sandpoint      29  37  35  41  29  37 /  50  70 100  70  30  70
Kellogg        31  37  36  39  32  36 /  40  50 100  80  60  80
Moses Lake     24  36  35  48  30  46 /  10  50 100  10  10  30
Wenatchee      30  35  35  47  34  45 /  10  80 100  10  10  40
Omak           30  35  33  45  27  39 /  10  90 100  20  10  40

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Air Stagnation Advisory until Noon PST Friday for Central
     Panhandle Mountains-Coeur d`Alene Area-Idaho Palouse-
     Northern Panhandle.

     Winter Storm Warning from Noon Friday to 6 PM PST Saturday for
     Northern Panhandle.

     Winter Storm Warning from Noon Friday to 6 AM PST Sunday for
     Central Panhandle Mountains.

WA...Air Stagnation Advisory until Noon PST Friday for East Slopes
     Northern Cascades-Lower Garfield and Asotin Counties-Moses
     Lake Area-Northeast Mountains-Okanogan Highlands-Spokane
     Area-Upper Columbia Basin-Washington Palouse-Waterville
     Plateau-Wenatchee Area.

     Winter Storm Warning from Noon Friday to 6 AM PST Saturday for
     East Slopes Northern Cascades-Okanogan Highlands-Okanogan
     Valley-Waterville Plateau.

     Winter Storm Warning from Noon Friday to 6 PM PST Saturday for
     Northeast Mountains.

&&

$$





000
FXUS66 KOTX 202345
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
345 PM PST THU NOV 20 2014

.SYNOPSIS...
A relatively quiet and cool overnight period with a few snow
showers over the north will give way to a sharp deterioration in
the weather on Friday as a strong and moist Pacific storm brings
valley rain and mountain snow Friday night followed by very windy
conditions on Saturday. An active and periodically wet weather
regime will continue through the next week.

&&

.DISCUSSION...
Tonight...A rather mushy but somewhat benign night is in store
fro the region. Satellite and radar indicate the exiting storm
band that brought light snow to the region on track to move off
to the east early this evening. Meanwhile the next minor trough is
diving into California with a weak northern branch wave scuttling
into southern British Columbia. Models suggest a weak and
shearing wave will exist between these two dynamic centers and
will transit the region tonight...but the weakening nature of this
system should bring little beyond a few snow showers concentrated
over the northeastern zones late tonight. Once again fog and the
potential fro some freezing drizzle will exist in the deep basin
where stubborn arctic air is pooling in these low elevations.

Friday through Saturday...Latest models are in good agreement and
consistent with bringing a very moist and very dynamic wave
through the region during this period. A strong warm front will
make short work of the leftover and now modified arctic air over
the eastern half of the forecast area with snow levels expected to
rise to the 4000 foot region. In the west the cold air will be
slower to scrub and snow levels will stay low through much of this
event...perhaps all of it in the northern Cascade valleys and the
Okanogan valley. Snow levels will rise...but not as aggressively
over the southern portions of the deep basin...leading to the
likelihood of at least minimal warning criteria accumulating snow
on the Waterville Plateau. The southern valleys such as the
Wenatchee River valley will see some snow but amounts will be
overall fairly light. The Cascade mountains above 3000 to 4000
feet will get hammered with snow with a 12 hour period of moist
isentropic lift augmented by upslope southeasterly low level flow.
All the existing Winter Storm Watches will be upgraded to warnings
with the afternoon package...as well as adding the Okanogan and
Waterville Plateau to the highlight mix.

Beginning Friday morning the isentropic moistening process
will promote increasing clouds...with light snow beginning over
the northern zones in the early afternoon. By Friday evening an
almost universal field of valley rain and mountain snow will
envelop the region...except for the aforementioned north
Cascades/Okanogan where snow will continue as the dominant
meteor.

A strong cold front will rip through the region Saturday morning
largely ending precipitation in the Cascades lee but promoting
enhanced upslope snow showers into the Idaho Panhandle mountains.
The big story on Saturday will be very windy conditions especially
over the eastern basin exposed terrain with gust potential picked
off of model sounding mixed layers up to 45 or 50 mph. Saturday
will be a well mixed day with much milder temperatures than we
have grown accustomed to. /Fugazzi

Saturday Night through Monday Night: In the wake of Saturday`s
cold front, the breezy afternoon winds will gradually subside
overnight. Don`t see a great push of dry air behind this front. We
should have clearing skies in most places. This will allow
temperatures to drop sharply, especially in the northern valleys.
Then fog and stratus will form overnight and persist into Sunday
morning. The northwesterly flow is very unstable so the Panhandle
mountains will continue to pile up snow Saturday night.

By Sunday, another Pacific system will quickly clip across the
area. Due to the strong westerly flow, the Cascades and Panhandle
will be favored with this system. Spokane metro area could see
a little snow Sunday morning but will change to rain in the
afternoon.

Confidence is much lower for Monday`s event. The models really
diverge from each other on track and timing so I have about as
much chance of being wrong as right on the forecast. Went with
likely wording for the Cascades/Panhandle and chance wording
elsewhere. As usual, Highway 2/I-90 will be the dividing line
between rain and snow.  RJ

Tuesday through Thanksgiving: This portion of the forecast is
quite complicated, which is important because it envelops one of
the busiest travels days of the year. Unfortunately, the models
are having a hard time coming to some agreement, which makes this,
unfortunately, a low confidence forecast. There is some higher
confidence for Tuesday, as a shortwave traversed the region in
northwest flow. This will bring better chances of precipitation to
the Cascades, and the higher terrain of northeast Washington and
the Idaho Panhandle. It was happens after Tuesday where things get
all mucked up. The Euro model has stuck to its guns, carving out a
larger trough over much of the US, keeping the Inland Northwest on
the western edge of the cold air mass. The GFS keeps any
influence of the cold air mass well to the east, instead building
a ridge of high pressure over the region. This ridge is more
amplified than it`s previous solutions. So, all in all, we didn`t
stray much from the previous forecasts, which weighted towards the
more consistent solution (colder). While this would bring snow
levels into the valleys, the north-northwesterly flow does not
look like it will have a ton of moisture to work with. Lots of
fine-tuning will be made to this portion of the forecast for sure.
ty

&&

.AVIATION...
00Z TAFS: MVFR Ceilings and vis will be common over the region
through tonight as a moist boundary layer and light winds exists
under a strong low level inversion...with IFR conditions likely
redeveloping mainly at the KMWH and KGEG vicinity TAF sites
overnight. On Friday an approaching Pacific storm system will
spread thickening clouds over the region as a warm front develops.
MVFR ceilings will probably remain common across the Columbia
basin except fro KLWS where VFR conditions are expected. Light
snow or rain may begin at the KEAT TAF site during the afternoon.
/MJF


&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        28  37  36  43  30  40 /  20  30 100  30  20  60
Coeur d`Alene  30  39  36  42  31  39 /  30  50 100  50  30  70
Pullman        29  41  36  43  34  42 /  10  10 100  70  40  60
Lewiston       32  44  40  48  36  47 /  10  10 100  70  30  50
Colville       25  37  34  44  20  38 /  30  70 100  50  10  60
Sandpoint      29  37  35  41  29  37 /  50  70 100  70  30  70
Kellogg        31  37  36  39  32  36 /  40  50 100  80  60  80
Moses Lake     24  36  35  48  30  46 /  10  50 100  10  10  30
Wenatchee      30  35  35  47  34  45 /  10  80 100  10  10  40
Omak           30  35  33  45  27  39 /  10  90 100  20  10  40

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Air Stagnation Advisory until Noon PST Friday for Central
     Panhandle Mountains-Coeur d`Alene Area-Idaho Palouse-
     Northern Panhandle.

     Winter Storm Warning from Noon Friday to 6 PM PST Saturday for
     Northern Panhandle.

     Winter Storm Warning from Noon Friday to 6 AM PST Sunday for
     Central Panhandle Mountains.

WA...Air Stagnation Advisory until Noon PST Friday for East Slopes
     Northern Cascades-Lower Garfield and Asotin Counties-Moses
     Lake Area-Northeast Mountains-Okanogan Highlands-Spokane
     Area-Upper Columbia Basin-Washington Palouse-Waterville
     Plateau-Wenatchee Area.

     Winter Storm Warning from Noon Friday to 6 AM PST Saturday for
     East Slopes Northern Cascades-Okanogan Highlands-Okanogan
     Valley-Waterville Plateau.

     Winter Storm Warning from Noon Friday to 6 PM PST Saturday for
     Northeast Mountains.

&&

$$




000
FXUS66 KPQR 202314
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
315 PM PST THU NOV 20 2014

.SYNOPSIS...TWO AREAS OF LOW PRES ARE MOVING ONTO THE WEST COAST
TODAY. ONE IS PUSHING ONSHORE ALONG THE BRITISH COLUMBIA
COAST...WHILE THE OTHER LOW IS ALONG THE N CALIFORNIA AND S OREGON
COAST. IN BETWEEN THESE TWO SYSTEMS...WE WILL SEE ONLY SOME LIGHT
SHOWERS LINGERING INTO TONIGHT. A STRONG AND MOIST FRONT WILL BRING
HEAVIER RAIN AND STRONG WINDS LATER TOMORROW INTO EARLY SAT. SNOW
LEVELS WILL LIKELY LOWER BELOW THE CASCADE PASSES BY SATURDAY
MORNING...WITH ACCUMULATING SNOW CONTINUING FOR MUCH OF THE WEEKEND.
A WEAK RIDGE IS EXPECTED TO BUILD OVER THE NE PAC EARLY NEXT
WEEK...BUT MAY NOT BE STRONG ENOUGH TO KEEP CONDITIONS COMPLETELY DRY
OVER THE PAC NW. THE TREND IS THEN TOWARD DRIER WEATHER NEXT WEEK.

&&

.SHORT TERM...TONIGHT THROUGH SUNDAY...
TWO AREAS OF LOW PRES ASSOCIATED WITH A SPLIT UPPER LEVEL TROUGH ARE
MOVING ONSHORE TO THE NORTH AND SOUTH OF US THIS AFTERNOON. THE LOW
TO THE NORTH IS MOVING ONTO THE BRITISH COLUMBIA COAST...WHILE THE
OTHER SITS ALONG THE S OREGON AND N CALIFORNIA COAST AND WILL MOVE
ONSHORE TONIGHT. IN BETWEEN...WE ARE SEEING ONLY SOME LIGHT SHOWERS
OVER SW WASHINGTON AND NW OREGON AS THE HIGHLY STRETCHED UPPER LEVEL
TROF AXIS MOVES OVER THE REGION. ALSO...THE LATEST SURFACE
OBSERVATIONS SHOW THAT TEMPS THROUGH THE COLUMBIA RIVER GORGE AND
UPPER HOOD RIVER VALLEY HAVE WARMED ABOVE FREEZING JUST ABOUT
EVERYWHERE. SO THE THREAT OF FREEZING RAIN APPEARS TO BE OVER FOR
NOW. THE FCST MODELS INDICATE THAT A FEW WEAK SHOWERS WILL LINGER
INTO TONIGHT. BASED ON THE CLEARING SKIES OFFSHORE APPARENT ON
VISIBLE SATELLITE...THINK WE WILL SEE SOME SCATTERING OF THE CLOUD
COVER TONIGHT. THIS SHOULD ALLOW FOR SOME PATCHY FOG AND LOW STRATUS
TO FORM OVERNIGHT. OTHERWISE...EXPECT FAIRLY QUIET CONDITIONS
OVERNIGHT.

A STRONG 150+ KT JET STREAK WILL APPROACH THE PAC NW TOMORROW. THIS
WILL DRIVE A STRONG AND MOIST FRONTAL SYSTEM ONSHORE LATER TOMORROW
AND TOMORROW NIGHT. AMSU SATELLITE DERIVED IMAGERY SHOWS A REGION OF
SUBTROPICAL MOISTURE WELL OFFSHORE THAT WILL FEED INTO THIS SYSTEM.
THE FCST MODELS INDICATE THAT PWAT VALUES WILL BE AROUND 1.25 INCHES
ALONG THE COAST AS THE LEADING WARM FRONT MOVES ONSHORE. WE EXPECT A
BATCH OF HEAVY RAIN TO PUSH INLAND DURING THE LATE AFTERNOON AND
EVENING...WITH 1.5 TO 2 INCHES OF RAIN LIKELY FOR THE COAST...COAST
RANGE AND CASCADES OVER ABOUT A 12 HR PERIOD. THE INTERIOR LOWLANDS
WILL BE LOWER...CLOSER TO AROUND AN INCH. IT DOES NOT APPEAR THAT
RAINFALL TOTALS WILL BE ENOUGH TO CAUSE ANY FLOODING CONCERNS.

THIS SYSTEM WILL ALSO BRING A BURST OF STRONG WINDS ALONG THE COAST
DURING THE AFTERNOON AND EVENING. WILL CONTINUE WITH A HIGH WIND
WATCH FOR THE ENTIRE COAST FOR THE AFTERNOON AND EVENING. A CORE OF
60 KT WINDS AT 925 MB ARE BEING ADVERTISED BY THE 12Z NAM...GFS...AND
ECMWF RUNS. WILL CONFINE THE HIGHEST WINDS TO THE
BEACHES AND COASTAL HEADLANDS...WHERE GUSTS TO 65 MPH ARE CURRENTLY
EXPECTED. THE COASTAL COMMUNITIES SHOULD ALSO BE GUSTY...BUT WILL
LIMIT WIND GUSTS TO 50-55 MPH FOR NOW.

IT IS LOOKING LESS LIKELY THAT FREEZING RAIN IN THE COLUMBIA RIVER
GORGE AND UPPER HOOD RIVER VALLEY WILL BE A CONCERN WITH THIS SYSTEM
BASED ON THE WARMING TEMPS SEEN TODAY. TEMPS SHOULD FALL BACK TO JUST
BELOW FREEZING TONIGHT EAST OF THE CASCADES...AND THE FCST MODELS
CONTINUE TO INDICATE THAT LIGHT EASTERLY FLOW WILL CONTINUE THROUGH
THE INITIAL ONSET OF PRECIP TOMORROW. SO WILL KEEP A SLIGHT CHC OF
FREEZING RAIN AROUND HOOD RIVER AND IN THE HOOD RIVER VALLEY THROUGH
TOMORROW AFTERNOON. DO NOT THINK THERE WILL BE WIDESPREAD
ACCUMULATIONS...BUT SOME PATCHY SPOTS OF ICE ARE DEFINITELY POSSIBLE.
WINDS WILL SWITCH TO WESTERLY DURING THE EVENING...WHICH WILL WARM
THINGS UP CONSIDERABLY AND PUT AN END TO ANY ICE CONCERNS.

THE COLD FRONT WILL MOVE THROUGH THE REGION TOMORROW NIGHT WITH SNOW
LEVELS FALLING RAPIDLY OVERNIGHT INTO SAT MORNING. EXPECT SNOW LEVELS
TO REMAIN BELOW THE CASCADE PASSES THROUGH THE WEEKEND...WITH SHOWERS
CONTINUING IN DECENT OROGRAPHIC FLOW. SNOW WILL BE HEAVIER AT TIMES
AS WEAK IMPULSES MOVE THROUGH ALOFT. AT THIS TIME...IT APPEARS THE
PERIOD OF BEST SNOWFALL ACCUMULATION WILL BE OVERNIGHT SAT INTO EARLY
SUN. THIS PERIOD MAY END UP NEEDING A WINTER WEATHER ADVISORY AS WE
GET CLOSER IN TIME. PYLE


.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY. THE MORE WESTERLY OR
ZONAL FLOW THAT SETS UP OVER THE WEEKEND DURING THE LATTER PART OF
THE SHORT TERM PERIOD BEGINS TO BUCKLE A BIT IN THE EARLY PART OF
THE LONG TERM PERIOD WITH SOME FLAT RIDGING DEVELOPING OVER THE
NORTHEAST PACIFIC. HAVE DECIDED TO CONTINUE TO STICK MORE WITH A
DIRTY RIDGE SCENARIO OF THE ECMWF VS THE HIGHER AMPLITUDE RIDGING OF
THE OPERATIONAL GFS MODEL. CONFIDENCE DECREASES THROUGHOUT THE LONG
TERM PERIOD AS MODEL VARIABILITY INCREASES...THOUGH THE TREND IS
TOWARD DRIER DURING THE MIDDLE TO LATTER PARTS OF NEXT WEEK. TOLLESON
&&

.AVIATION...MAINLY VFR CIGS THIS AFTERNOON...EXCEPT NEAR SALEM IN
CENTRAL WILLAMETTE VALLEY IS LIKELY TO KEEP LOW MVFR THROUGH THIS
EVENING. MVFR AND IFR LIKELY TO RETURN TONIGHT ACROSS THE AREA.
KTTD STILL GUSTING TO 25 KTS...KEEPING VFR CONDITIONS OVER KTTD.
THESE WINDS SHOULD WEAKEN TO 10 KT AFTER 06Z TONIGHT...BUT WEAK
AND DRY EASTERLIES MAY INHIBIT MVFR OR IFR.

SHOWERS MOVE THROUGH THE REGION AHEAD OF OUR NEXT COLD FRONT FRIDAY.
THIS WILL BRING SHOWERS AND OCCASIONAL MVFR ACROSS THE AREA EARLY
FRIDAY. WINDS INCREASE ACROSS THE AREA AROUND 18Z FRIDAY FROM THE
SOUTH. COLD FRONT LOOKS TO MOVE THROUGH LATE FRIDAY.


KPDX AND APPROACHES...MAINLY VFR THIS EVENING...DROPPING TO MVFR
AROUND 08Z TONIGHT. MVFR SHOULD PERSIST THROUGH FRIDAY
MORNING WITH SCATTERED SHOWERS...BEFORE LIFTING AROUND 18Z AS
WIND INCREASES FROM THE SOUTH.

&&

.MARINE...15 TO 20 KT WINDS WITH GUSTS NEAR 25 KTS TONIGHT WILL
INCREASE TO 20 TO 25 KT WITH GUSTS TO 30 BY FRIDAY MORNING. WINDS
CONTINUE TO INCREASE THROUGH THE DAY FRIDAY AHEAD OF A STRONG COLD
FRONT. WINDS INCREASE TO 35 TO 40 KTS FRIDAY AFTERNOON...WITH
GUSTS TO 50 KTS...MAINLY IN THE INNER WATERS. WINDS SUBSIDE TO 20
TO 25 KTS BEHIND THE FRONT LATE FRIDAY.

SEAS ARE BETWEEN 8 TO 10 FT RIGHT NOW...BUT WILL BUILD OVERNIGHT
TONIGHT
TO 10 TO 12 FT. SEAS CONTINUE TO RISE DURING THE DAY ON FRIDAY
AHEAD OF OUR NEXT COLD FRONT...BUILDING TO AROUND 20 FT FRIDAY
AFTERNOON. SEA SEAS DROP FAIRLY QUICKLY BEHIND THE COLD FRONT AS
WINDS WEAKEN...BUT SEAS LOOK TO REMAIN ABOVE 10 FT THROUGH THIS
WEEKEND.

-MCCOY

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...HIGH WIND WATCH FROM FRIDAY MORNING THROUGH FRIDAY EVENING FOR
     CENTRAL OREGON COAST-NORTH OREGON COAST.

WA...HIGH WIND WATCH FROM FRIDAY MORNING THROUGH FRIDAY EVENING FOR
     SOUTH WASHINGTON COAST.

PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 AM PST FRIDAY FOR
    COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     GALE WARNING FROM 10 AM TO 10 PM PST FRIDAY FOR COASTAL WATERS
    FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 3 PM PST THIS
     AFTERNOON FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
    FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 6 PM
    PST THIS EVENING.

&&

$$

INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND

THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.




000
FXUS66 KPQR 202314
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
315 PM PST THU NOV 20 2014

.SYNOPSIS...TWO AREAS OF LOW PRES ARE MOVING ONTO THE WEST COAST
TODAY. ONE IS PUSHING ONSHORE ALONG THE BRITISH COLUMBIA
COAST...WHILE THE OTHER LOW IS ALONG THE N CALIFORNIA AND S OREGON
COAST. IN BETWEEN THESE TWO SYSTEMS...WE WILL SEE ONLY SOME LIGHT
SHOWERS LINGERING INTO TONIGHT. A STRONG AND MOIST FRONT WILL BRING
HEAVIER RAIN AND STRONG WINDS LATER TOMORROW INTO EARLY SAT. SNOW
LEVELS WILL LIKELY LOWER BELOW THE CASCADE PASSES BY SATURDAY
MORNING...WITH ACCUMULATING SNOW CONTINUING FOR MUCH OF THE WEEKEND.
A WEAK RIDGE IS EXPECTED TO BUILD OVER THE NE PAC EARLY NEXT
WEEK...BUT MAY NOT BE STRONG ENOUGH TO KEEP CONDITIONS COMPLETELY DRY
OVER THE PAC NW. THE TREND IS THEN TOWARD DRIER WEATHER NEXT WEEK.

&&

.SHORT TERM...TONIGHT THROUGH SUNDAY...
TWO AREAS OF LOW PRES ASSOCIATED WITH A SPLIT UPPER LEVEL TROUGH ARE
MOVING ONSHORE TO THE NORTH AND SOUTH OF US THIS AFTERNOON. THE LOW
TO THE NORTH IS MOVING ONTO THE BRITISH COLUMBIA COAST...WHILE THE
OTHER SITS ALONG THE S OREGON AND N CALIFORNIA COAST AND WILL MOVE
ONSHORE TONIGHT. IN BETWEEN...WE ARE SEEING ONLY SOME LIGHT SHOWERS
OVER SW WASHINGTON AND NW OREGON AS THE HIGHLY STRETCHED UPPER LEVEL
TROF AXIS MOVES OVER THE REGION. ALSO...THE LATEST SURFACE
OBSERVATIONS SHOW THAT TEMPS THROUGH THE COLUMBIA RIVER GORGE AND
UPPER HOOD RIVER VALLEY HAVE WARMED ABOVE FREEZING JUST ABOUT
EVERYWHERE. SO THE THREAT OF FREEZING RAIN APPEARS TO BE OVER FOR
NOW. THE FCST MODELS INDICATE THAT A FEW WEAK SHOWERS WILL LINGER
INTO TONIGHT. BASED ON THE CLEARING SKIES OFFSHORE APPARENT ON
VISIBLE SATELLITE...THINK WE WILL SEE SOME SCATTERING OF THE CLOUD
COVER TONIGHT. THIS SHOULD ALLOW FOR SOME PATCHY FOG AND LOW STRATUS
TO FORM OVERNIGHT. OTHERWISE...EXPECT FAIRLY QUIET CONDITIONS
OVERNIGHT.

A STRONG 150+ KT JET STREAK WILL APPROACH THE PAC NW TOMORROW. THIS
WILL DRIVE A STRONG AND MOIST FRONTAL SYSTEM ONSHORE LATER TOMORROW
AND TOMORROW NIGHT. AMSU SATELLITE DERIVED IMAGERY SHOWS A REGION OF
SUBTROPICAL MOISTURE WELL OFFSHORE THAT WILL FEED INTO THIS SYSTEM.
THE FCST MODELS INDICATE THAT PWAT VALUES WILL BE AROUND 1.25 INCHES
ALONG THE COAST AS THE LEADING WARM FRONT MOVES ONSHORE. WE EXPECT A
BATCH OF HEAVY RAIN TO PUSH INLAND DURING THE LATE AFTERNOON AND
EVENING...WITH 1.5 TO 2 INCHES OF RAIN LIKELY FOR THE COAST...COAST
RANGE AND CASCADES OVER ABOUT A 12 HR PERIOD. THE INTERIOR LOWLANDS
WILL BE LOWER...CLOSER TO AROUND AN INCH. IT DOES NOT APPEAR THAT
RAINFALL TOTALS WILL BE ENOUGH TO CAUSE ANY FLOODING CONCERNS.

THIS SYSTEM WILL ALSO BRING A BURST OF STRONG WINDS ALONG THE COAST
DURING THE AFTERNOON AND EVENING. WILL CONTINUE WITH A HIGH WIND
WATCH FOR THE ENTIRE COAST FOR THE AFTERNOON AND EVENING. A CORE OF
60 KT WINDS AT 925 MB ARE BEING ADVERTISED BY THE 12Z NAM...GFS...AND
ECMWF RUNS. WILL CONFINE THE HIGHEST WINDS TO THE
BEACHES AND COASTAL HEADLANDS...WHERE GUSTS TO 65 MPH ARE CURRENTLY
EXPECTED. THE COASTAL COMMUNITIES SHOULD ALSO BE GUSTY...BUT WILL
LIMIT WIND GUSTS TO 50-55 MPH FOR NOW.

IT IS LOOKING LESS LIKELY THAT FREEZING RAIN IN THE COLUMBIA RIVER
GORGE AND UPPER HOOD RIVER VALLEY WILL BE A CONCERN WITH THIS SYSTEM
BASED ON THE WARMING TEMPS SEEN TODAY. TEMPS SHOULD FALL BACK TO JUST
BELOW FREEZING TONIGHT EAST OF THE CASCADES...AND THE FCST MODELS
CONTINUE TO INDICATE THAT LIGHT EASTERLY FLOW WILL CONTINUE THROUGH
THE INITIAL ONSET OF PRECIP TOMORROW. SO WILL KEEP A SLIGHT CHC OF
FREEZING RAIN AROUND HOOD RIVER AND IN THE HOOD RIVER VALLEY THROUGH
TOMORROW AFTERNOON. DO NOT THINK THERE WILL BE WIDESPREAD
ACCUMULATIONS...BUT SOME PATCHY SPOTS OF ICE ARE DEFINITELY POSSIBLE.
WINDS WILL SWITCH TO WESTERLY DURING THE EVENING...WHICH WILL WARM
THINGS UP CONSIDERABLY AND PUT AN END TO ANY ICE CONCERNS.

THE COLD FRONT WILL MOVE THROUGH THE REGION TOMORROW NIGHT WITH SNOW
LEVELS FALLING RAPIDLY OVERNIGHT INTO SAT MORNING. EXPECT SNOW LEVELS
TO REMAIN BELOW THE CASCADE PASSES THROUGH THE WEEKEND...WITH SHOWERS
CONTINUING IN DECENT OROGRAPHIC FLOW. SNOW WILL BE HEAVIER AT TIMES
AS WEAK IMPULSES MOVE THROUGH ALOFT. AT THIS TIME...IT APPEARS THE
PERIOD OF BEST SNOWFALL ACCUMULATION WILL BE OVERNIGHT SAT INTO EARLY
SUN. THIS PERIOD MAY END UP NEEDING A WINTER WEATHER ADVISORY AS WE
GET CLOSER IN TIME. PYLE


.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY. THE MORE WESTERLY OR
ZONAL FLOW THAT SETS UP OVER THE WEEKEND DURING THE LATTER PART OF
THE SHORT TERM PERIOD BEGINS TO BUCKLE A BIT IN THE EARLY PART OF
THE LONG TERM PERIOD WITH SOME FLAT RIDGING DEVELOPING OVER THE
NORTHEAST PACIFIC. HAVE DECIDED TO CONTINUE TO STICK MORE WITH A
DIRTY RIDGE SCENARIO OF THE ECMWF VS THE HIGHER AMPLITUDE RIDGING OF
THE OPERATIONAL GFS MODEL. CONFIDENCE DECREASES THROUGHOUT THE LONG
TERM PERIOD AS MODEL VARIABILITY INCREASES...THOUGH THE TREND IS
TOWARD DRIER DURING THE MIDDLE TO LATTER PARTS OF NEXT WEEK. TOLLESON
&&

.AVIATION...MAINLY VFR CIGS THIS AFTERNOON...EXCEPT NEAR SALEM IN
CENTRAL WILLAMETTE VALLEY IS LIKELY TO KEEP LOW MVFR THROUGH THIS
EVENING. MVFR AND IFR LIKELY TO RETURN TONIGHT ACROSS THE AREA.
KTTD STILL GUSTING TO 25 KTS...KEEPING VFR CONDITIONS OVER KTTD.
THESE WINDS SHOULD WEAKEN TO 10 KT AFTER 06Z TONIGHT...BUT WEAK
AND DRY EASTERLIES MAY INHIBIT MVFR OR IFR.

SHOWERS MOVE THROUGH THE REGION AHEAD OF OUR NEXT COLD FRONT FRIDAY.
THIS WILL BRING SHOWERS AND OCCASIONAL MVFR ACROSS THE AREA EARLY
FRIDAY. WINDS INCREASE ACROSS THE AREA AROUND 18Z FRIDAY FROM THE
SOUTH. COLD FRONT LOOKS TO MOVE THROUGH LATE FRIDAY.


KPDX AND APPROACHES...MAINLY VFR THIS EVENING...DROPPING TO MVFR
AROUND 08Z TONIGHT. MVFR SHOULD PERSIST THROUGH FRIDAY
MORNING WITH SCATTERED SHOWERS...BEFORE LIFTING AROUND 18Z AS
WIND INCREASES FROM THE SOUTH.

&&

.MARINE...15 TO 20 KT WINDS WITH GUSTS NEAR 25 KTS TONIGHT WILL
INCREASE TO 20 TO 25 KT WITH GUSTS TO 30 BY FRIDAY MORNING. WINDS
CONTINUE TO INCREASE THROUGH THE DAY FRIDAY AHEAD OF A STRONG COLD
FRONT. WINDS INCREASE TO 35 TO 40 KTS FRIDAY AFTERNOON...WITH
GUSTS TO 50 KTS...MAINLY IN THE INNER WATERS. WINDS SUBSIDE TO 20
TO 25 KTS BEHIND THE FRONT LATE FRIDAY.

SEAS ARE BETWEEN 8 TO 10 FT RIGHT NOW...BUT WILL BUILD OVERNIGHT
TONIGHT
TO 10 TO 12 FT. SEAS CONTINUE TO RISE DURING THE DAY ON FRIDAY
AHEAD OF OUR NEXT COLD FRONT...BUILDING TO AROUND 20 FT FRIDAY
AFTERNOON. SEA SEAS DROP FAIRLY QUICKLY BEHIND THE COLD FRONT AS
WINDS WEAKEN...BUT SEAS LOOK TO REMAIN ABOVE 10 FT THROUGH THIS
WEEKEND.

-MCCOY

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...HIGH WIND WATCH FROM FRIDAY MORNING THROUGH FRIDAY EVENING FOR
     CENTRAL OREGON COAST-NORTH OREGON COAST.

WA...HIGH WIND WATCH FROM FRIDAY MORNING THROUGH FRIDAY EVENING FOR
     SOUTH WASHINGTON COAST.

PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 AM PST FRIDAY FOR
    COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     GALE WARNING FROM 10 AM TO 10 PM PST FRIDAY FOR COASTAL WATERS
    FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 3 PM PST THIS
     AFTERNOON FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
    FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 6 PM
    PST THIS EVENING.

&&

$$

INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND

THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.



000
FXUS66 KOTX 202219
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
218 PM PST THU NOV 20 2014

.SYNOPSIS...
A relatively quiet and cool overnight period with a few snow
showers over the north will give way to a sharp deterioration in
the weather on Friday as a strong and moist Pacific storm brings
valley rain and mountain snow Friday night followed by very windy
conditions on Saturday. An active and periodically wet weather
regime will continue through the next week.

&&

.DISCUSSION...
Tonight...A rather mushy but somewhat benign night is in store
fro the region. Satellite and radar indicate the exiting storm
band that brought light snow to the region on track to move off
to the east early this evening. Meanwhile the next minor trough is
diving into California with a weak northern branch wave scuttling
into southern British Columbia. Models suggest a weak and
shearing wave will exist between these two dynamic centers and
will transit the region tonight...but the weakening nature of this
system should bring little beyond a few snow showers concentrated
over the northeastern zones late tonight. Once again fog and the
potential fro some freezing drizzle will exist in the deep basin
where stubborn arctic air is pooling in these low elevations.

Friday through Saturday...Latest models are in good agreement and
consistent with bringing a very moist and very dynamic wave
through the region during this period. A strong warm front will
make short work of the leftover and now modified arctic air over
the eastern half of the forecast area with snow levels expected to
rise to the 4000 foot region. In the west the cold air will be
slower to scrub and snow levels will stay low through much of this
event...perhaps all of it in the northern Cascade valleys and the
Okanogan valley. Snow levels will rise...but not as aggressively
over the southern portions of the deep basin...leading to the
likelihood of at least minimal warning criteria accumulating snow
on the Waterville Plateau. The southern valleys such as the
Wenatchee River valley will see some snow but amounts will be
overall fairly light. The Cascade mountains above 3000 to 4000
feet will get hammered with snow with a 12 hour period of moist
isentropic lift augmented by upslope southeasterly low level flow.
All the existing Winter Storm Watches will be upgraded to warnings
with the afternoon package...as well as adding the Okanogan and
Waterville Plateau to the highlight mix.

Beginning Friday morning the isentropic moistening process
will promote increasing clouds...with light snow beginning over
the northern zones in the early afternoon. By Friday evening an
almost universal field of valley rain and mountain snow will
envelop the region...except for the aforementioned north
Cascades/Okanogan where snow will continue as the dominant
meteor.

A strong cold front will rip through the region Saturday morning
largely ending precipitation in the Cascades lee but promoting
enhanced upslope snow showers into the Idaho Panhandle mountains.
The big story on Saturday will be very windy conditions especially
over the eastern basin exposed terrain with gust potential picked
off of model sounding mixed layers up to 45 or 50 mph. Saturday
will be a well mixed day with much milder temperatures than we
have grown accustomed to. /Fugazzi

Saturday Night through Monday Night: In the wake of Saturday`s
cold front, the breezy afternoon winds will gradually subside
overnight. Don`t see a great push of dry air behind this front. We
should have clearing skies in most places. This will allow
temperatures to drop sharply, especially in the northern valleys.
Then fog and stratus will form overnight and persist into Sunday
morning. The northwesterly flow is very unstable so the Panhandle
mountains will continue to pile up snow Saturday night.

By Sunday, another Pacific system will quickly clip across the
area. Due to the strong westerly flow, the Cascades and Panhandle
will be favored with this system. Spokane metro area could see
a little snow Sunday morning but will change to rain in the
afternoon.

Confidence is much lower for Monday`s event. The models really
diverge from each other on track and timing so I have about as
much chance of being wrong as right on the forecast. Went with
likely wording for the Cascades/Panhandle and chance wording
elsewhere. As usual, Highway 2/I-90 will be the dividing line
between rain and snow.  RJ

Tuesday through Thanksgiving: This portion of the forecast is
quite complicated, which is important because it envelops one of
the busiest travels days of the year. Unfortunately, the models
are having a hard time coming to some agreement, which makes this,
unfortunately, a low confidence forecast. There is some higher
confidence for Tuesday, as a shortwave traversed the region in
northwest flow. This will bring better chances of precipitation to
the Cascades, and the higher terrain of northeast Washington and
the Idaho Panhandle. It was happens after Tuesday where things get
all mucked up. The Euro model has stuck to its guns, carving out a
larger trough over much of the US, keeping the Inland Northwest on
the western edge of the cold air mass. The GFS keeps any
influence of the cold air mass well to the east, instead building
a ridge of high pressure over the region. This ridge is more
amplified than it`s previous solutions. So, all in all, we didn`t
stray much from the previous forecasts, which weighted towards the
more consistent solution (colder). While this would bring snow
levels into the valleys, the north-northwesterly flow does not
look like it will have a ton of moisture to work with. Lots of
fine-tuning will be made to this portion of the forecast for sure.
ty

&&

.AVIATION...
18Z TAFS: A WEAK FRONTAL BOUNDARY WILL CONTINUE TO LIFT TO THE
NORTHEAST THIS MORNING...MOVING OUT OF THE KGEG/KPUW/KLWS TAF
SITES BY 20Z. HOWEVER...THE BOUNDARY LAYER REMAINS VERY MOIST AND
A STRONG INVERSION ALOFT REMAINS OVER THE AREA. MVFR AND SOME IFR
CEILINGS WILL REMAIN AT MOST TAF SITES EXCEPT KLWS AND KEAT
THROUGH THE NEXT 24 HOURS. A SECOND WEAK DISTURBANCE WILL TRANSIT
THE REGION BETWEEN 12Z AND 18Z FRIDAY MAINLY THREATENING THE KGEG
AREA TAF SITES WITH -SN. THERE IS A POSSIBILITY OF THIS
PRECIPITATION MANIFESTING ITSELF AS -FZRA THOUGH AT THIS TIME
CONFIDENCE IS LOW. /MJF


&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        28  37  36  43  30  40 /  20  30 100  30  20  60
Coeur d`Alene  30  39  36  42  31  39 /  30  50 100  50  30  70
Pullman        29  41  36  43  34  42 /  10  10 100  70  40  60
Lewiston       32  44  40  48  36  47 /  10  10 100  70  30  50
Colville       25  37  34  44  20  38 /  30  70 100  50  10  60
Sandpoint      29  37  35  41  29  37 /  50  70 100  70  30  70
Kellogg        31  37  36  39  32  36 /  40  50 100  80  60  80
Moses Lake     24  36  35  48  30  46 /  10  50 100  10  10  30
Wenatchee      30  35  35  47  34  45 /  10  80 100  10  10  40
Omak           30  35  33  45  27  39 /  10  90 100  20  10  40

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Air Stagnation Advisory until Noon PST Friday for Central
     Panhandle Mountains-Coeur d`Alene Area-Idaho Palouse-
     Northern Panhandle.

     Winter Storm Warning from Noon Friday to 6 PM PST Saturday for
     Northern Panhandle.

     Winter Storm Warning from Noon Friday to 6 AM PST Sunday for
     Central Panhandle Mountains.

WA...Air Stagnation Advisory until Noon PST Friday for East Slopes
     Northern Cascades-Lower Garfield and Asotin Counties-Moses
     Lake Area-Northeast Mountains-Okanogan Highlands-Spokane
     Area-Upper Columbia Basin-Washington Palouse-Waterville
     Plateau-Wenatchee Area.

     Winter Storm Warning from Noon Friday to 6 AM PST Saturday for
     East Slopes Northern Cascades-Okanogan Highlands-Okanogan
     Valley-Waterville Plateau.

     Winter Storm Warning from Noon Friday to 6 PM PST Saturday for
     Northeast Mountains.

&&

$$




000
FXUS66 KOTX 202219
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
218 PM PST THU NOV 20 2014

.SYNOPSIS...
A relatively quiet and cool overnight period with a few snow
showers over the north will give way to a sharp deterioration in
the weather on Friday as a strong and moist Pacific storm brings
valley rain and mountain snow Friday night followed by very windy
conditions on Saturday. An active and periodically wet weather
regime will continue through the next week.

&&

.DISCUSSION...
Tonight...A rather mushy but somewhat benign night is in store
fro the region. Satellite and radar indicate the exiting storm
band that brought light snow to the region on track to move off
to the east early this evening. Meanwhile the next minor trough is
diving into California with a weak northern branch wave scuttling
into southern British Columbia. Models suggest a weak and
shearing wave will exist between these two dynamic centers and
will transit the region tonight...but the weakening nature of this
system should bring little beyond a few snow showers concentrated
over the northeastern zones late tonight. Once again fog and the
potential fro some freezing drizzle will exist in the deep basin
where stubborn arctic air is pooling in these low elevations.

Friday through Saturday...Latest models are in good agreement and
consistent with bringing a very moist and very dynamic wave
through the region during this period. A strong warm front will
make short work of the leftover and now modified arctic air over
the eastern half of the forecast area with snow levels expected to
rise to the 4000 foot region. In the west the cold air will be
slower to scrub and snow levels will stay low through much of this
event...perhaps all of it in the northern Cascade valleys and the
Okanogan valley. Snow levels will rise...but not as aggressively
over the southern portions of the deep basin...leading to the
likelihood of at least minimal warning criteria accumulating snow
on the Waterville Plateau. The southern valleys such as the
Wenatchee River valley will see some snow but amounts will be
overall fairly light. The Cascade mountains above 3000 to 4000
feet will get hammered with snow with a 12 hour period of moist
isentropic lift augmented by upslope southeasterly low level flow.
All the existing Winter Storm Watches will be upgraded to warnings
with the afternoon package...as well as adding the Okanogan and
Waterville Plateau to the highlight mix.

Beginning Friday morning the isentropic moistening process
will promote increasing clouds...with light snow beginning over
the northern zones in the early afternoon. By Friday evening an
almost universal field of valley rain and mountain snow will
envelop the region...except for the aforementioned north
Cascades/Okanogan where snow will continue as the dominant
meteor.

A strong cold front will rip through the region Saturday morning
largely ending precipitation in the Cascades lee but promoting
enhanced upslope snow showers into the Idaho Panhandle mountains.
The big story on Saturday will be very windy conditions especially
over the eastern basin exposed terrain with gust potential picked
off of model sounding mixed layers up to 45 or 50 mph. Saturday
will be a well mixed day with much milder temperatures than we
have grown accustomed to. /Fugazzi

Saturday Night through Monday Night: In the wake of Saturday`s
cold front, the breezy afternoon winds will gradually subside
overnight. Don`t see a great push of dry air behind this front. We
should have clearing skies in most places. This will allow
temperatures to drop sharply, especially in the northern valleys.
Then fog and stratus will form overnight and persist into Sunday
morning. The northwesterly flow is very unstable so the Panhandle
mountains will continue to pile up snow Saturday night.

By Sunday, another Pacific system will quickly clip across the
area. Due to the strong westerly flow, the Cascades and Panhandle
will be favored with this system. Spokane metro area could see
a little snow Sunday morning but will change to rain in the
afternoon.

Confidence is much lower for Monday`s event. The models really
diverge from each other on track and timing so I have about as
much chance of being wrong as right on the forecast. Went with
likely wording for the Cascades/Panhandle and chance wording
elsewhere. As usual, Highway 2/I-90 will be the dividing line
between rain and snow.  RJ

Tuesday through Thanksgiving: This portion of the forecast is
quite complicated, which is important because it envelops one of
the busiest travels days of the year. Unfortunately, the models
are having a hard time coming to some agreement, which makes this,
unfortunately, a low confidence forecast. There is some higher
confidence for Tuesday, as a shortwave traversed the region in
northwest flow. This will bring better chances of precipitation to
the Cascades, and the higher terrain of northeast Washington and
the Idaho Panhandle. It was happens after Tuesday where things get
all mucked up. The Euro model has stuck to its guns, carving out a
larger trough over much of the US, keeping the Inland Northwest on
the western edge of the cold air mass. The GFS keeps any
influence of the cold air mass well to the east, instead building
a ridge of high pressure over the region. This ridge is more
amplified than it`s previous solutions. So, all in all, we didn`t
stray much from the previous forecasts, which weighted towards the
more consistent solution (colder). While this would bring snow
levels into the valleys, the north-northwesterly flow does not
look like it will have a ton of moisture to work with. Lots of
fine-tuning will be made to this portion of the forecast for sure.
ty

&&

.AVIATION...
18Z TAFS: A WEAK FRONTAL BOUNDARY WILL CONTINUE TO LIFT TO THE
NORTHEAST THIS MORNING...MOVING OUT OF THE KGEG/KPUW/KLWS TAF
SITES BY 20Z. HOWEVER...THE BOUNDARY LAYER REMAINS VERY MOIST AND
A STRONG INVERSION ALOFT REMAINS OVER THE AREA. MVFR AND SOME IFR
CEILINGS WILL REMAIN AT MOST TAF SITES EXCEPT KLWS AND KEAT
THROUGH THE NEXT 24 HOURS. A SECOND WEAK DISTURBANCE WILL TRANSIT
THE REGION BETWEEN 12Z AND 18Z FRIDAY MAINLY THREATENING THE KGEG
AREA TAF SITES WITH -SN. THERE IS A POSSIBILITY OF THIS
PRECIPITATION MANIFESTING ITSELF AS -FZRA THOUGH AT THIS TIME
CONFIDENCE IS LOW. /MJF


&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        28  37  36  43  30  40 /  20  30 100  30  20  60
Coeur d`Alene  30  39  36  42  31  39 /  30  50 100  50  30  70
Pullman        29  41  36  43  34  42 /  10  10 100  70  40  60
Lewiston       32  44  40  48  36  47 /  10  10 100  70  30  50
Colville       25  37  34  44  20  38 /  30  70 100  50  10  60
Sandpoint      29  37  35  41  29  37 /  50  70 100  70  30  70
Kellogg        31  37  36  39  32  36 /  40  50 100  80  60  80
Moses Lake     24  36  35  48  30  46 /  10  50 100  10  10  30
Wenatchee      30  35  35  47  34  45 /  10  80 100  10  10  40
Omak           30  35  33  45  27  39 /  10  90 100  20  10  40

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Air Stagnation Advisory until Noon PST Friday for Central
     Panhandle Mountains-Coeur d`Alene Area-Idaho Palouse-
     Northern Panhandle.

     Winter Storm Warning from Noon Friday to 6 PM PST Saturday for
     Northern Panhandle.

     Winter Storm Warning from Noon Friday to 6 AM PST Sunday for
     Central Panhandle Mountains.

WA...Air Stagnation Advisory until Noon PST Friday for East Slopes
     Northern Cascades-Lower Garfield and Asotin Counties-Moses
     Lake Area-Northeast Mountains-Okanogan Highlands-Spokane
     Area-Upper Columbia Basin-Washington Palouse-Waterville
     Plateau-Wenatchee Area.

     Winter Storm Warning from Noon Friday to 6 AM PST Saturday for
     East Slopes Northern Cascades-Okanogan Highlands-Okanogan
     Valley-Waterville Plateau.

     Winter Storm Warning from Noon Friday to 6 PM PST Saturday for
     Northeast Mountains.

&&

$$





000
FXUS66 KOTX 201756
AFDOTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
956 AM PST THU NOV 20 2014

.SYNOPSIS...
A WEAK WEATHER SYSTEM WILL PASS THROUGH TODAY WITH THE POTENTIAL
FOR A LIGHT WINTRY MIX OF RAIN...SNOW...AND FREEZING RAIN. A
STRONGER, WETTER AND WINDIER WEATHER SYSTEM WILL ARRIVE FRIDAY
PERSISTING INTO THE WEEKEND WITH HEAVY SNOW AMOUNTS POSSIBLE OVER
THE MOUNTAINS. THE WEATHER PATTERN WILL REMAIN ACTIVE THROUGH THE
MIDDLE OF NEXT WEEK.

&&

.DISCUSSION...
REST OF TODAY...THE WEAK WAVE WHICH BROUGHT A WINTRY MIX OF MINOR
PRECIPITATION TO THE AREA IS MAINLY IMPACTING THE NORTHEASTERN
ZONES AT 10AM AS IT SLOWLY MOVES OFF. THIS REGION OF NOW MAINLY
LIGHT SNOW WILL CONTINUE TO DEPOSIT LIGHT ACCUMULATIONS MAINLY TO
THE NORTHEASTERN ZONES AS IT MOVES INTO MONTANA LATER TODAY.

A SECOND AREA OF LIGHT PRECIPITATION IS MOVING INTO THE CASCADES
FROM THE WEST SIDE...BUT NOT MUCH OF THIS SYSTEM IS EXPECTED TO
SURVIVE THE TRIP ACROSS THE MOUNTAINS TODAY. HOWEVER...THE LOW
LEVEL AIR MASS REMAINS SATURATED THROUGH OUT THE REGION AND THIS
WILL PROMOTE AREAS OF FOG AND LOW CLOUDS THROUGH MUCH OF THE DAY
OVER MUCH OF THE REGION EVEN AFTER PRECIPITATION TAPERS OFF. THE
BEST CHANCE OF SUN WILL BE IN THE AREAS TUCKED AGAINST THE
CASCADES FROM WENATCHEE TO OMAK UNTIL HIGHER CLOUDS BLEEDING OVER
THE CASCADES STREAM IN AND FILTER THE SUN...MAYBE EVEN INCLUDING A
BRIEF SNOW SHOWER THIS AFTERNOON. MINOR UPDATES TO ZONE FORECASTS
ALREADY PUBLISHED. NO UPDATE TO STATE FORECAST PRODUCT
EXPECTED./FUGAZZI

&&

.AVIATION...
18Z TAFS: A WEAK FRONTAL BOUNDARY WILL CONTINUE TO LIFT TO THE
NORTHEAST THIS MORNING...MOVING OUT OF THE KGEG/KPUW/KLWS TAF
SITES BY 20Z. HOWEVER...THE BOUNDARY LAYER REMAINS VERY MOIST AND
A STRONG INVERSION ALOFT REMAINS OVER THE AREA. MVFR AND SOME IFR
CEILINGS WILL REMAIN AT MOST TAF SITES EXCEPT KLWS AND KEAT
THROUGH THE NEXT 24 HOURS. A SECOND WEAK DISTURBANCE WILL TRANSIT
THE REGION BETWEEN 12Z AND 18Z FRIDAY MAINLY THREATENING THE KGEG
AREA TAF SITES WITH -SN. THERE IS A POSSIBILITY OF THIS
PRECIPITATION MANIFESTING ITSELF AS -FZRA THOUGH AT THIS TIME
CONFIDECNE IS LOW. /MJF

&&

.PRELIMINARY POINT TEMPS/POPS...
SPOKANE        33  29  38  34  42  29 /  10  30  40 100  60  30
COEUR D`ALENE  33  29  40  33  41  31 /  30  50  50 100  70  30
PULLMAN        39  29  42  35  42  32 /  10  10  20 100  70  30
LEWISTON       41  32  45  39  47  35 /  10  10  10  80  50  30
COLVILLE       33  26  38  34  43  26 /  50  50  70 100  40  30
SANDPOINT      35  29  39  33  41  29 /  50  70  70 100  70  30
KELLOGG        35  30  39  32  39  32 /  70  50  60 100  90  40
MOSES LAKE     34  24  37  31  47  28 /  20  10  70 100  30  20
WENATCHEE      37  29  36  31  45  31 /  30  10  80 100  20  30
OMAK           34  26  37  30  43  27 /  20  10  90 100  20  30

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...AIR STAGNATION ADVISORY UNTIL NOON PST FRIDAY FOR CENTRAL
     PANHANDLE MOUNTAINS-COEUR D`ALENE AREA-IDAHO PALOUSE-
     NORTHERN PANHANDLE.

     WINTER STORM WATCH FROM FRIDAY AFTERNOON THROUGH SATURDAY
     AFTERNOON FOR CENTRAL PANHANDLE MOUNTAINS-NORTHERN
     PANHANDLE.

WA...AIR STAGNATION ADVISORY UNTIL NOON PST FRIDAY FOR EAST SLOPES
     NORTHERN CASCADES-LOWER GARFIELD AND ASOTIN COUNTIES-MOSES
     LAKE AREA-NORTHEAST MOUNTAINS-OKANOGAN HIGHLANDS-SPOKANE
     AREA-UPPER COLUMBIA BASIN-WASHINGTON PALOUSE-WATERVILLE
     PLATEAU-WENATCHEE AREA.

     WINTER STORM WATCH FROM FRIDAY AFTERNOON THROUGH SATURDAY
     AFTERNOON FOR NORTHEAST MOUNTAINS-OKANOGAN HIGHLANDS.

     WINTER STORM WATCH FROM FRIDAY MORNING THROUGH LATE FRIDAY NIGHT
     FOR EAST SLOPES NORTHERN CASCADES.

&&

$$




000
FXUS66 KOTX 201756
AFDOTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
956 AM PST THU NOV 20 2014

.SYNOPSIS...
A WEAK WEATHER SYSTEM WILL PASS THROUGH TODAY WITH THE POTENTIAL
FOR A LIGHT WINTRY MIX OF RAIN...SNOW...AND FREEZING RAIN. A
STRONGER, WETTER AND WINDIER WEATHER SYSTEM WILL ARRIVE FRIDAY
PERSISTING INTO THE WEEKEND WITH HEAVY SNOW AMOUNTS POSSIBLE OVER
THE MOUNTAINS. THE WEATHER PATTERN WILL REMAIN ACTIVE THROUGH THE
MIDDLE OF NEXT WEEK.

&&

.DISCUSSION...
REST OF TODAY...THE WEAK WAVE WHICH BROUGHT A WINTRY MIX OF MINOR
PRECIPITATION TO THE AREA IS MAINLY IMPACTING THE NORTHEASTERN
ZONES AT 10AM AS IT SLOWLY MOVES OFF. THIS REGION OF NOW MAINLY
LIGHT SNOW WILL CONTINUE TO DEPOSIT LIGHT ACCUMULATIONS MAINLY TO
THE NORTHEASTERN ZONES AS IT MOVES INTO MONTANA LATER TODAY.

A SECOND AREA OF LIGHT PRECIPITATION IS MOVING INTO THE CASCADES
FROM THE WEST SIDE...BUT NOT MUCH OF THIS SYSTEM IS EXPECTED TO
SURVIVE THE TRIP ACROSS THE MOUNTAINS TODAY. HOWEVER...THE LOW
LEVEL AIR MASS REMAINS SATURATED THROUGH OUT THE REGION AND THIS
WILL PROMOTE AREAS OF FOG AND LOW CLOUDS THROUGH MUCH OF THE DAY
OVER MUCH OF THE REGION EVEN AFTER PRECIPITATION TAPERS OFF. THE
BEST CHANCE OF SUN WILL BE IN THE AREAS TUCKED AGAINST THE
CASCADES FROM WENATCHEE TO OMAK UNTIL HIGHER CLOUDS BLEEDING OVER
THE CASCADES STREAM IN AND FILTER THE SUN...MAYBE EVEN INCLUDING A
BRIEF SNOW SHOWER THIS AFTERNOON. MINOR UPDATES TO ZONE FORECASTS
ALREADY PUBLISHED. NO UPDATE TO STATE FORECAST PRODUCT
EXPECTED./FUGAZZI

&&

.AVIATION...
18Z TAFS: A WEAK FRONTAL BOUNDARY WILL CONTINUE TO LIFT TO THE
NORTHEAST THIS MORNING...MOVING OUT OF THE KGEG/KPUW/KLWS TAF
SITES BY 20Z. HOWEVER...THE BOUNDARY LAYER REMAINS VERY MOIST AND
A STRONG INVERSION ALOFT REMAINS OVER THE AREA. MVFR AND SOME IFR
CEILINGS WILL REMAIN AT MOST TAF SITES EXCEPT KLWS AND KEAT
THROUGH THE NEXT 24 HOURS. A SECOND WEAK DISTURBANCE WILL TRANSIT
THE REGION BETWEEN 12Z AND 18Z FRIDAY MAINLY THREATENING THE KGEG
AREA TAF SITES WITH -SN. THERE IS A POSSIBILITY OF THIS
PRECIPITATION MANIFESTING ITSELF AS -FZRA THOUGH AT THIS TIME
CONFIDECNE IS LOW. /MJF

&&

.PRELIMINARY POINT TEMPS/POPS...
SPOKANE        33  29  38  34  42  29 /  10  30  40 100  60  30
COEUR D`ALENE  33  29  40  33  41  31 /  30  50  50 100  70  30
PULLMAN        39  29  42  35  42  32 /  10  10  20 100  70  30
LEWISTON       41  32  45  39  47  35 /  10  10  10  80  50  30
COLVILLE       33  26  38  34  43  26 /  50  50  70 100  40  30
SANDPOINT      35  29  39  33  41  29 /  50  70  70 100  70  30
KELLOGG        35  30  39  32  39  32 /  70  50  60 100  90  40
MOSES LAKE     34  24  37  31  47  28 /  20  10  70 100  30  20
WENATCHEE      37  29  36  31  45  31 /  30  10  80 100  20  30
OMAK           34  26  37  30  43  27 /  20  10  90 100  20  30

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...AIR STAGNATION ADVISORY UNTIL NOON PST FRIDAY FOR CENTRAL
     PANHANDLE MOUNTAINS-COEUR D`ALENE AREA-IDAHO PALOUSE-
     NORTHERN PANHANDLE.

     WINTER STORM WATCH FROM FRIDAY AFTERNOON THROUGH SATURDAY
     AFTERNOON FOR CENTRAL PANHANDLE MOUNTAINS-NORTHERN
     PANHANDLE.

WA...AIR STAGNATION ADVISORY UNTIL NOON PST FRIDAY FOR EAST SLOPES
     NORTHERN CASCADES-LOWER GARFIELD AND ASOTIN COUNTIES-MOSES
     LAKE AREA-NORTHEAST MOUNTAINS-OKANOGAN HIGHLANDS-SPOKANE
     AREA-UPPER COLUMBIA BASIN-WASHINGTON PALOUSE-WATERVILLE
     PLATEAU-WENATCHEE AREA.

     WINTER STORM WATCH FROM FRIDAY AFTERNOON THROUGH SATURDAY
     AFTERNOON FOR NORTHEAST MOUNTAINS-OKANOGAN HIGHLANDS.

     WINTER STORM WATCH FROM FRIDAY MORNING THROUGH LATE FRIDAY NIGHT
     FOR EAST SLOPES NORTHERN CASCADES.

&&

$$




000
FXUS66 KOTX 201756
AFDOTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
956 AM PST THU NOV 20 2014

.SYNOPSIS...
A WEAK WEATHER SYSTEM WILL PASS THROUGH TODAY WITH THE POTENTIAL
FOR A LIGHT WINTRY MIX OF RAIN...SNOW...AND FREEZING RAIN. A
STRONGER, WETTER AND WINDIER WEATHER SYSTEM WILL ARRIVE FRIDAY
PERSISTING INTO THE WEEKEND WITH HEAVY SNOW AMOUNTS POSSIBLE OVER
THE MOUNTAINS. THE WEATHER PATTERN WILL REMAIN ACTIVE THROUGH THE
MIDDLE OF NEXT WEEK.

&&

.DISCUSSION...
REST OF TODAY...THE WEAK WAVE WHICH BROUGHT A WINTRY MIX OF MINOR
PRECIPITATION TO THE AREA IS MAINLY IMPACTING THE NORTHEASTERN
ZONES AT 10AM AS IT SLOWLY MOVES OFF. THIS REGION OF NOW MAINLY
LIGHT SNOW WILL CONTINUE TO DEPOSIT LIGHT ACCUMULATIONS MAINLY TO
THE NORTHEASTERN ZONES AS IT MOVES INTO MONTANA LATER TODAY.

A SECOND AREA OF LIGHT PRECIPITATION IS MOVING INTO THE CASCADES
FROM THE WEST SIDE...BUT NOT MUCH OF THIS SYSTEM IS EXPECTED TO
SURVIVE THE TRIP ACROSS THE MOUNTAINS TODAY. HOWEVER...THE LOW
LEVEL AIR MASS REMAINS SATURATED THROUGH OUT THE REGION AND THIS
WILL PROMOTE AREAS OF FOG AND LOW CLOUDS THROUGH MUCH OF THE DAY
OVER MUCH OF THE REGION EVEN AFTER PRECIPITATION TAPERS OFF. THE
BEST CHANCE OF SUN WILL BE IN THE AREAS TUCKED AGAINST THE
CASCADES FROM WENATCHEE TO OMAK UNTIL HIGHER CLOUDS BLEEDING OVER
THE CASCADES STREAM IN AND FILTER THE SUN...MAYBE EVEN INCLUDING A
BRIEF SNOW SHOWER THIS AFTERNOON. MINOR UPDATES TO ZONE FORECASTS
ALREADY PUBLISHED. NO UPDATE TO STATE FORECAST PRODUCT
EXPECTED./FUGAZZI

&&

.AVIATION...
18Z TAFS: A WEAK FRONTAL BOUNDARY WILL CONTINUE TO LIFT TO THE
NORTHEAST THIS MORNING...MOVING OUT OF THE KGEG/KPUW/KLWS TAF
SITES BY 20Z. HOWEVER...THE BOUNDARY LAYER REMAINS VERY MOIST AND
A STRONG INVERSION ALOFT REMAINS OVER THE AREA. MVFR AND SOME IFR
CEILINGS WILL REMAIN AT MOST TAF SITES EXCEPT KLWS AND KEAT
THROUGH THE NEXT 24 HOURS. A SECOND WEAK DISTURBANCE WILL TRANSIT
THE REGION BETWEEN 12Z AND 18Z FRIDAY MAINLY THREATENING THE KGEG
AREA TAF SITES WITH -SN. THERE IS A POSSIBILITY OF THIS
PRECIPITATION MANIFESTING ITSELF AS -FZRA THOUGH AT THIS TIME
CONFIDECNE IS LOW. /MJF

&&

.PRELIMINARY POINT TEMPS/POPS...
SPOKANE        33  29  38  34  42  29 /  10  30  40 100  60  30
COEUR D`ALENE  33  29  40  33  41  31 /  30  50  50 100  70  30
PULLMAN        39  29  42  35  42  32 /  10  10  20 100  70  30
LEWISTON       41  32  45  39  47  35 /  10  10  10  80  50  30
COLVILLE       33  26  38  34  43  26 /  50  50  70 100  40  30
SANDPOINT      35  29  39  33  41  29 /  50  70  70 100  70  30
KELLOGG        35  30  39  32  39  32 /  70  50  60 100  90  40
MOSES LAKE     34  24  37  31  47  28 /  20  10  70 100  30  20
WENATCHEE      37  29  36  31  45  31 /  30  10  80 100  20  30
OMAK           34  26  37  30  43  27 /  20  10  90 100  20  30

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...AIR STAGNATION ADVISORY UNTIL NOON PST FRIDAY FOR CENTRAL
     PANHANDLE MOUNTAINS-COEUR D`ALENE AREA-IDAHO PALOUSE-
     NORTHERN PANHANDLE.

     WINTER STORM WATCH FROM FRIDAY AFTERNOON THROUGH SATURDAY
     AFTERNOON FOR CENTRAL PANHANDLE MOUNTAINS-NORTHERN
     PANHANDLE.

WA...AIR STAGNATION ADVISORY UNTIL NOON PST FRIDAY FOR EAST SLOPES
     NORTHERN CASCADES-LOWER GARFIELD AND ASOTIN COUNTIES-MOSES
     LAKE AREA-NORTHEAST MOUNTAINS-OKANOGAN HIGHLANDS-SPOKANE
     AREA-UPPER COLUMBIA BASIN-WASHINGTON PALOUSE-WATERVILLE
     PLATEAU-WENATCHEE AREA.

     WINTER STORM WATCH FROM FRIDAY AFTERNOON THROUGH SATURDAY
     AFTERNOON FOR NORTHEAST MOUNTAINS-OKANOGAN HIGHLANDS.

     WINTER STORM WATCH FROM FRIDAY MORNING THROUGH LATE FRIDAY NIGHT
     FOR EAST SLOPES NORTHERN CASCADES.

&&

$$




000
FXUS66 KOTX 201756
AFDOTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
956 AM PST THU NOV 20 2014

.SYNOPSIS...
A WEAK WEATHER SYSTEM WILL PASS THROUGH TODAY WITH THE POTENTIAL
FOR A LIGHT WINTRY MIX OF RAIN...SNOW...AND FREEZING RAIN. A
STRONGER, WETTER AND WINDIER WEATHER SYSTEM WILL ARRIVE FRIDAY
PERSISTING INTO THE WEEKEND WITH HEAVY SNOW AMOUNTS POSSIBLE OVER
THE MOUNTAINS. THE WEATHER PATTERN WILL REMAIN ACTIVE THROUGH THE
MIDDLE OF NEXT WEEK.

&&

.DISCUSSION...
REST OF TODAY...THE WEAK WAVE WHICH BROUGHT A WINTRY MIX OF MINOR
PRECIPITATION TO THE AREA IS MAINLY IMPACTING THE NORTHEASTERN
ZONES AT 10AM AS IT SLOWLY MOVES OFF. THIS REGION OF NOW MAINLY
LIGHT SNOW WILL CONTINUE TO DEPOSIT LIGHT ACCUMULATIONS MAINLY TO
THE NORTHEASTERN ZONES AS IT MOVES INTO MONTANA LATER TODAY.

A SECOND AREA OF LIGHT PRECIPITATION IS MOVING INTO THE CASCADES
FROM THE WEST SIDE...BUT NOT MUCH OF THIS SYSTEM IS EXPECTED TO
SURVIVE THE TRIP ACROSS THE MOUNTAINS TODAY. HOWEVER...THE LOW
LEVEL AIR MASS REMAINS SATURATED THROUGH OUT THE REGION AND THIS
WILL PROMOTE AREAS OF FOG AND LOW CLOUDS THROUGH MUCH OF THE DAY
OVER MUCH OF THE REGION EVEN AFTER PRECIPITATION TAPERS OFF. THE
BEST CHANCE OF SUN WILL BE IN THE AREAS TUCKED AGAINST THE
CASCADES FROM WENATCHEE TO OMAK UNTIL HIGHER CLOUDS BLEEDING OVER
THE CASCADES STREAM IN AND FILTER THE SUN...MAYBE EVEN INCLUDING A
BRIEF SNOW SHOWER THIS AFTERNOON. MINOR UPDATES TO ZONE FORECASTS
ALREADY PUBLISHED. NO UPDATE TO STATE FORECAST PRODUCT
EXPECTED./FUGAZZI

&&

.AVIATION...
18Z TAFS: A WEAK FRONTAL BOUNDARY WILL CONTINUE TO LIFT TO THE
NORTHEAST THIS MORNING...MOVING OUT OF THE KGEG/KPUW/KLWS TAF
SITES BY 20Z. HOWEVER...THE BOUNDARY LAYER REMAINS VERY MOIST AND
A STRONG INVERSION ALOFT REMAINS OVER THE AREA. MVFR AND SOME IFR
CEILINGS WILL REMAIN AT MOST TAF SITES EXCEPT KLWS AND KEAT
THROUGH THE NEXT 24 HOURS. A SECOND WEAK DISTURBANCE WILL TRANSIT
THE REGION BETWEEN 12Z AND 18Z FRIDAY MAINLY THREATENING THE KGEG
AREA TAF SITES WITH -SN. THERE IS A POSSIBILITY OF THIS
PRECIPITATION MANIFESTING ITSELF AS -FZRA THOUGH AT THIS TIME
CONFIDECNE IS LOW. /MJF

&&

.PRELIMINARY POINT TEMPS/POPS...
SPOKANE        33  29  38  34  42  29 /  10  30  40 100  60  30
COEUR D`ALENE  33  29  40  33  41  31 /  30  50  50 100  70  30
PULLMAN        39  29  42  35  42  32 /  10  10  20 100  70  30
LEWISTON       41  32  45  39  47  35 /  10  10  10  80  50  30
COLVILLE       33  26  38  34  43  26 /  50  50  70 100  40  30
SANDPOINT      35  29  39  33  41  29 /  50  70  70 100  70  30
KELLOGG        35  30  39  32  39  32 /  70  50  60 100  90  40
MOSES LAKE     34  24  37  31  47  28 /  20  10  70 100  30  20
WENATCHEE      37  29  36  31  45  31 /  30  10  80 100  20  30
OMAK           34  26  37  30  43  27 /  20  10  90 100  20  30

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...AIR STAGNATION ADVISORY UNTIL NOON PST FRIDAY FOR CENTRAL
     PANHANDLE MOUNTAINS-COEUR D`ALENE AREA-IDAHO PALOUSE-
     NORTHERN PANHANDLE.

     WINTER STORM WATCH FROM FRIDAY AFTERNOON THROUGH SATURDAY
     AFTERNOON FOR CENTRAL PANHANDLE MOUNTAINS-NORTHERN
     PANHANDLE.

WA...AIR STAGNATION ADVISORY UNTIL NOON PST FRIDAY FOR EAST SLOPES
     NORTHERN CASCADES-LOWER GARFIELD AND ASOTIN COUNTIES-MOSES
     LAKE AREA-NORTHEAST MOUNTAINS-OKANOGAN HIGHLANDS-SPOKANE
     AREA-UPPER COLUMBIA BASIN-WASHINGTON PALOUSE-WATERVILLE
     PLATEAU-WENATCHEE AREA.

     WINTER STORM WATCH FROM FRIDAY AFTERNOON THROUGH SATURDAY
     AFTERNOON FOR NORTHEAST MOUNTAINS-OKANOGAN HIGHLANDS.

     WINTER STORM WATCH FROM FRIDAY MORNING THROUGH LATE FRIDAY NIGHT
     FOR EAST SLOPES NORTHERN CASCADES.

&&

$$




000
FXUS66 KPQR 201736
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
932 AM PST THU NOV 20 2014

.SYNOPSIS...TWO LOW PRES SYSTEMS ARE MOVING ONTO THE PAC NW TODAY AND
TONIGHT. THE NORTHERN LOW IS MOVING ONSHORE ALONG THE BRITISH
COLUMBIA COAST...WHILE THE SOUTHERN LOW WILL MOVE ONSHORE LATER TODAY
OVER NORTHERN CALIFORNIA AND SOUTHERN OREGON. A BAND OF RAIN
ASSOCIATED WITH THE UPPER LOW IS MOVING THROUGH THIS MORNING...WITH
FREEZING RAIN CONTINUING TO IMPACT THE CENTRAL COLUMBIA RIVER GORGE
AND UPPER HOOD RIVER VALLEY. PRECIPITATION WILL BECOME LESS ORGANIZED
THIS AFTERNOON...BUT SCATTERED SHOWERS WILL REMAIN INTO TONIGHT. A
WELL
ORGANIZED MOIST FRONT WILL BRING HEAVIER RAIN AND STRONG WINDS LATER
FRIDAY AND SATURDAY WITH RAIN AND MOUNTAIN SNOW SHOWERS CONTINUING
THROUGH THE WEEKEND. SNOW LEVELS WILL LIKELY LOWER BELOW THE CASCADE
PASSES BY SATURDAY MORNING.

&&

.SHORT TERM...A SPLIT UPPER LEVEL TROUGH AND TWO ASSOCIATED SURFACE
LOWS ARE AFFECTING THE PAC NW TODAY. THE NORTHERNMOST LOW IS PUSHING
ONSHORE ALONG THE BRITISH COLUMBIA COAST THIS MORNING...WHILE THE
SOUTHERN LOW IS OFF THE SOUTHERN OREGON COAST. A BAND OF MORE
ORGANIZED PRECIPITATION BEING DRIVEN BY THE APPROACHING UPPER TROUGH
AXIS AND SOME ISENTROPIC LIFT AHEAD OF THE SOUTHERN LOW IS APPARENT
ON RADAR OVER THE S WA CASCADES THROUGH THE COLUMBIA RIVER GORGE AND
UPPER HOOD RIVER VALLEY. WITH TEMPS STILL JUST BELOW FREEZING THROUGH
THE CENTRAL GORGE AND HOOD RIVER VALLEY...EXPECT SOME ADDITIONAL
LIGHT ICE ACCUMULATIONS IN THESE AREAS ON TOP OF AROUND A TENTH OF AN
INCH OR MORE THAT SOME AREAS REPORTEDLY RECEIVED OVERNIGHT.  EXPECT
TEMPERATURES THROUGH MUCH OF THE GORGE WILL RISE TO ABOVE FREEZING
THIS AFTERNOON. ALSO EXPECT PRECIPITATION TO TAPER OFF THIS
AFTERNOON...WITH ONLY A FEW SCATTERED SHOWERS REMAINING INTO TONIGHT
AS THE UPPER TROUGH AXIS PUSHES THROUGH. THUS...THINK THE CURRENT
EXPIRATION TIME OF 21Z ON THE FREEZING RAIN ADVISORY LOOKS GOOD.

ANOTHER STRONGER SYSTEM IS ON TAP FOR FRI INTO SAT. BASED ON THE
LATEST MODEL RUNS...IT IS LOOKING INCREASINGLY LIKELY THAT HIGH
WINDS WILL IMPACT THE COAST. THE 12Z NAM AND GFS AND 00Z ECMWF ALL
SUGGEST A CORE OF 60+ KT LOW LEVEL WINDS WILL COME THROUGH FRI
AFTERNOON AND EVENING...ALTHOUGH THE 00Z ECMWF IS STRONGER AND ABOUT
6 HRS SLOWER WITH THE SYSTEM. DESPITE SOME UNCERTAINTY IN THE
OVERALL TIMING...FELT CONFIDENT ENOUGH TO ISSUE A HIGH WIND WATCH
FOR THE COASTAL BEACHES AND HEADLANDS BEGINNING MIDDAY FRI THROUGH
FRI EVENING.

THE MOST DIFFICULT FCST CHALLENGE WITH THE FRI SYSTEM IS THE
POTENTIAL FOR MORE FREEZING RAIN FOR THE UPPER HOOD RIVER VALLEY AND
CENTRAL COLUMBIA GORGE. ALTHOUGH TEMPERATURES THROUGH MOST OF THE
GORGE ARE EXPECTED TO RISE ABOVE FREEZING BY THIS AFTERNOON...THE
FCST MODELS ARE SUGGESTING THAT SOME LIGHT EASTERLY WINDS CONTINUE
INTO FRI AFTERNOON. WITH TEMPS LIKELY REMAINING JUST BELOW FREEZING
ON THE EAST SIDE OF THE CASCADES...AND THE SLIGHT UPSLOPE COMPONENT
TO THE E FLOW INTO THE HOOD RIVER VALLEY...THERE MAY BE A BRIEF
PERIOD OF FREEZING RAIN AT THE ONSET OF PRECIPITATION FRI.
HOWEVER...FAIRLY STRONG WESTERLY FLOW ARRIVES LATER FRI AFTERNOON OR
EARLY EVENING...WHICH SHOULD QUICKLY SWITCH PRECIPITATION OVER TO
RAIN.

OTHER THAN THE COASTAL WINDS AND FREEZING RAIN POTENTIAL...THE MAIN
IMPACT FOR MOST OF THE REGION FROM THIS SYSTEM WILL BE A PERIOD OF
HEAVY RAINS. THE BULK OF THE RAIN SHOULD FALL FRI AFTERNOON AND
EVENING. RIVERS WILL LIKELY MAKE A QUICK UPTURN BUT QPF AMOUNTS AND
DURATION INDICATE ACTION LEVELS ARE NOT LIKELY.

WHILE THE LOWLANDS WILL REMAIN MILD DURING THE UPCOMING PERIOD OF
ACTIVE WEATHER...THE CASCADES WILL BE RECEIVING ACCUMULATING SNOWFALL
DOWN TO THE PASSES AFTER THE FRONT GOES THROUGH OVERNIGHT FRI INTO
SAT. POST FRONTAL OROGRAPHICS LOOK PRETTY GOOD THROUGH THE
WEEKEND...SO EXPECT WE WILL NEED TO LOOK AT ISSUING AN ADVISORY FOR
SNOWFALL AS WE GET CLOSER. PYLE/26

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...SATURDAY NIGHT
THROUGH WEDNESDAY. THE MORE WESTERLY OR ZONAL FLOW THAT SETS UP LATE
IN THE SHORT TERM PERIOD CONTINUES INTO THE LONG TERM PERIOD...WITH
OCCASIONAL RAIN AS DISTURBANCES MOVE THROUGH. SOME RIDGING DEVELOPS
IN THE NORTHEAST PACIFIC EARLY NEXT WEEK...THOUGH THE MODELS VARY ON
HOW MUCH. THE NORMALLY MORE RELIABLE ECMWF MODEL HAS FLATTER RIDGING
WITH MORE OF A DIRTY RIDGE TYPE PATTERN AND DOES BRING SOME
PRECIPITATION INTO THE FORECAST AREA AT TIMES...WHILE THE OPERATIONAL
GFS MODEL SHOWS MORE AMPLITUDE DEVELOPING AND POSSIBLY SOME DRYING.
THE PARALLEL VERSION OF THE GFS MODEL IS A BIT MORE LIKE THE ECMWF.
HAVE KEPT OUR CURRENT TRENDS WHICH ARE MORE LIKE THE ECMWF AND THE
PARALLEL GFS MODEL...THOUGH CONFIDENCE IN ANY DETAILS ARE NOT VERY
HIGH AT THIS POINT. TOLLESON

&&

.AVIATION...SCATTERED SHOWERS ARE MOVING OFF TO THE
EAST...ALLOWING CIGS TO IMPROVE ACROSS THE AREA. SOME MVFR AND IFR
REMAINS IN MORE SHELTERED LOCATIONS...BUT THESE SHOULD START TO
IMPROVE BY 21Z. ANOTHER BAND OF SHOWERS WILL MOVE THROUGH THIS
AFTERNOON...WITH CHANCE OF OCCASIONAL MVFR CIGS DURING THESE
SHOWERS. MVFR TO IFR CONDITIONS TO RETURN LATE TONIGHT...MAINLY
ACROSS PORTIONS OF THE SOUTH WILLAMETTE VALLEY.

EASTERLY WIND STILL GUSTING OUT OF THE GORGE TO 25 KT AT KTTD...BUT
SHOULD WIND DOWN TO 10 KT BY 18Z.

KPDX AND APPROACHES...MAINLY VFR TODAY. OCCASIONAL MVFR POSSIBLE
WHEN SHOWERS MOVE THROUGH THIS AFTERNOON.

&&

.MARINE...SMALL CRAFT ADVISORY WINDS WITH GUSTS NEAR 25 KTS TODAY
WILL INCREASE THIS EVENING TO 20 TO 25 KTS GUSTING TO 30 KTS
TONIGHT. WINDS WILL CONTINUE TO RAMP UP FRI MORNING AHEAD OF THE
NEXT FRONTAL SYSTEM...WHICH WILL BE MUCH STRONGER THAN THE LAST
SYSTEM. GALES LOOKING VERY POSSIBLE DURING THE DAY
FRIDAY...AS A COASTAL JET DEVELOPS INITIALLY ALONG THE SOUTH OR
BUILDING NORTHWARD FRIDAY AFTERNOON.

SEAS TODAY WILL STAY AROUND 10 FT...AND WILL START TO BUILD AGAIN
OVERNIGHT TONIGHT WITH THE INCREASING WINDS. SEAS WILL REACH THE
MIDDLE TO UPPER TEENS FRIDAY MORNING...BUILDING TO AROUND 20 FT
MIDDAY FRIDAY. ONCE THE WINDS START TO WEAKEN FRIDAY NIGHT...SEAS
SHOULD DROP FAIRLY QUICKLY...BACK TO 10 TO 12 FT LATE FRIDAY NIGHT
OR EARLY SATURDAY MORNING. SEAS LOOK LIKELY TO REMAIN ABOVE 10 FT
THROUGH THE WEEKEND.

-MCCOY

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...HIGH WIND WATCH FROM FRIDAY MORNING THROUGH FRIDAY EVENING FOR
     CENTRAL OREGON COAST-NORTH OREGON COAST.

     FREEZING RAIN ADVISORY UNTIL 1 PM PST THIS AFTERNOON FOR CENTRAL

     COLUMBIA RIVER GORGE-UPPER HOOD RIVER VALLEY-WESTERN
     COLUMBIA RIVER GORGE.

WA...HIGH WIND WATCH FROM FRIDAY MORNING THROUGH FRIDAY EVENING FOR
     SOUTH WASHINGTON COAST.

     FREEZING RAIN ADVISORY UNTIL 1 PM PST THIS AFTERNOON FOR CENTRAL

     COLUMBIA RIVER GORGE-WESTERN COLUMBIA RIVER GORGE.

PZ...SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 1 PM THIS
AFTERNOON TO 6
     PM PST THIS EVENING.

     SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 AM PST FRIDAY FOR COASTAL
WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 3 PM PST THIS
     AFTERNOON FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE
OR OUT 60 NM.

&&


&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING RAIN ADVISORY UNTIL 1 PM PST THIS AFTERNOON FOR CENTRAL

     COLUMBIA RIVER GORGE-UPPER HOOD RIVER VALLEY-WESTERN
     COLUMBIA RIVER GORGE.

WA...FREEZING RAIN ADVISORY UNTIL 1 PM PST THIS AFTERNOON FOR CENTRAL

     COLUMBIA RIVER GORGE-WESTERN COLUMBIA RIVER GORGE.

PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 7 AM PST THIS MORNING FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT 60
NM.

     SMALL CRAFT ADVISORY FOR WINDS FROM 10 AM THIS MORNING TO 4 AM
     PST FRIDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
     FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 3 PM PST THIS
     AFTERNOON FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
     FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 1 PM
     THIS AFTERNOON TO 6 PM PST THIS EVENING.

&&

$$

INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND

THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.




000
FXUS66 KPQR 201736
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
932 AM PST THU NOV 20 2014

.SYNOPSIS...TWO LOW PRES SYSTEMS ARE MOVING ONTO THE PAC NW TODAY AND
TONIGHT. THE NORTHERN LOW IS MOVING ONSHORE ALONG THE BRITISH
COLUMBIA COAST...WHILE THE SOUTHERN LOW WILL MOVE ONSHORE LATER TODAY
OVER NORTHERN CALIFORNIA AND SOUTHERN OREGON. A BAND OF RAIN
ASSOCIATED WITH THE UPPER LOW IS MOVING THROUGH THIS MORNING...WITH
FREEZING RAIN CONTINUING TO IMPACT THE CENTRAL COLUMBIA RIVER GORGE
AND UPPER HOOD RIVER VALLEY. PRECIPITATION WILL BECOME LESS ORGANIZED
THIS AFTERNOON...BUT SCATTERED SHOWERS WILL REMAIN INTO TONIGHT. A
WELL
ORGANIZED MOIST FRONT WILL BRING HEAVIER RAIN AND STRONG WINDS LATER
FRIDAY AND SATURDAY WITH RAIN AND MOUNTAIN SNOW SHOWERS CONTINUING
THROUGH THE WEEKEND. SNOW LEVELS WILL LIKELY LOWER BELOW THE CASCADE
PASSES BY SATURDAY MORNING.

&&

.SHORT TERM...A SPLIT UPPER LEVEL TROUGH AND TWO ASSOCIATED SURFACE
LOWS ARE AFFECTING THE PAC NW TODAY. THE NORTHERNMOST LOW IS PUSHING
ONSHORE ALONG THE BRITISH COLUMBIA COAST THIS MORNING...WHILE THE
SOUTHERN LOW IS OFF THE SOUTHERN OREGON COAST. A BAND OF MORE
ORGANIZED PRECIPITATION BEING DRIVEN BY THE APPROACHING UPPER TROUGH
AXIS AND SOME ISENTROPIC LIFT AHEAD OF THE SOUTHERN LOW IS APPARENT
ON RADAR OVER THE S WA CASCADES THROUGH THE COLUMBIA RIVER GORGE AND
UPPER HOOD RIVER VALLEY. WITH TEMPS STILL JUST BELOW FREEZING THROUGH
THE CENTRAL GORGE AND HOOD RIVER VALLEY...EXPECT SOME ADDITIONAL
LIGHT ICE ACCUMULATIONS IN THESE AREAS ON TOP OF AROUND A TENTH OF AN
INCH OR MORE THAT SOME AREAS REPORTEDLY RECEIVED OVERNIGHT.  EXPECT
TEMPERATURES THROUGH MUCH OF THE GORGE WILL RISE TO ABOVE FREEZING
THIS AFTERNOON. ALSO EXPECT PRECIPITATION TO TAPER OFF THIS
AFTERNOON...WITH ONLY A FEW SCATTERED SHOWERS REMAINING INTO TONIGHT
AS THE UPPER TROUGH AXIS PUSHES THROUGH. THUS...THINK THE CURRENT
EXPIRATION TIME OF 21Z ON THE FREEZING RAIN ADVISORY LOOKS GOOD.

ANOTHER STRONGER SYSTEM IS ON TAP FOR FRI INTO SAT. BASED ON THE
LATEST MODEL RUNS...IT IS LOOKING INCREASINGLY LIKELY THAT HIGH
WINDS WILL IMPACT THE COAST. THE 12Z NAM AND GFS AND 00Z ECMWF ALL
SUGGEST A CORE OF 60+ KT LOW LEVEL WINDS WILL COME THROUGH FRI
AFTERNOON AND EVENING...ALTHOUGH THE 00Z ECMWF IS STRONGER AND ABOUT
6 HRS SLOWER WITH THE SYSTEM. DESPITE SOME UNCERTAINTY IN THE
OVERALL TIMING...FELT CONFIDENT ENOUGH TO ISSUE A HIGH WIND WATCH
FOR THE COASTAL BEACHES AND HEADLANDS BEGINNING MIDDAY FRI THROUGH
FRI EVENING.

THE MOST DIFFICULT FCST CHALLENGE WITH THE FRI SYSTEM IS THE
POTENTIAL FOR MORE FREEZING RAIN FOR THE UPPER HOOD RIVER VALLEY AND
CENTRAL COLUMBIA GORGE. ALTHOUGH TEMPERATURES THROUGH MOST OF THE
GORGE ARE EXPECTED TO RISE ABOVE FREEZING BY THIS AFTERNOON...THE
FCST MODELS ARE SUGGESTING THAT SOME LIGHT EASTERLY WINDS CONTINUE
INTO FRI AFTERNOON. WITH TEMPS LIKELY REMAINING JUST BELOW FREEZING
ON THE EAST SIDE OF THE CASCADES...AND THE SLIGHT UPSLOPE COMPONENT
TO THE E FLOW INTO THE HOOD RIVER VALLEY...THERE MAY BE A BRIEF
PERIOD OF FREEZING RAIN AT THE ONSET OF PRECIPITATION FRI.
HOWEVER...FAIRLY STRONG WESTERLY FLOW ARRIVES LATER FRI AFTERNOON OR
EARLY EVENING...WHICH SHOULD QUICKLY SWITCH PRECIPITATION OVER TO
RAIN.

OTHER THAN THE COASTAL WINDS AND FREEZING RAIN POTENTIAL...THE MAIN
IMPACT FOR MOST OF THE REGION FROM THIS SYSTEM WILL BE A PERIOD OF
HEAVY RAINS. THE BULK OF THE RAIN SHOULD FALL FRI AFTERNOON AND
EVENING. RIVERS WILL LIKELY MAKE A QUICK UPTURN BUT QPF AMOUNTS AND
DURATION INDICATE ACTION LEVELS ARE NOT LIKELY.

WHILE THE LOWLANDS WILL REMAIN MILD DURING THE UPCOMING PERIOD OF
ACTIVE WEATHER...THE CASCADES WILL BE RECEIVING ACCUMULATING SNOWFALL
DOWN TO THE PASSES AFTER THE FRONT GOES THROUGH OVERNIGHT FRI INTO
SAT. POST FRONTAL OROGRAPHICS LOOK PRETTY GOOD THROUGH THE
WEEKEND...SO EXPECT WE WILL NEED TO LOOK AT ISSUING AN ADVISORY FOR
SNOWFALL AS WE GET CLOSER. PYLE/26

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...SATURDAY NIGHT
THROUGH WEDNESDAY. THE MORE WESTERLY OR ZONAL FLOW THAT SETS UP LATE
IN THE SHORT TERM PERIOD CONTINUES INTO THE LONG TERM PERIOD...WITH
OCCASIONAL RAIN AS DISTURBANCES MOVE THROUGH. SOME RIDGING DEVELOPS
IN THE NORTHEAST PACIFIC EARLY NEXT WEEK...THOUGH THE MODELS VARY ON
HOW MUCH. THE NORMALLY MORE RELIABLE ECMWF MODEL HAS FLATTER RIDGING
WITH MORE OF A DIRTY RIDGE TYPE PATTERN AND DOES BRING SOME
PRECIPITATION INTO THE FORECAST AREA AT TIMES...WHILE THE OPERATIONAL
GFS MODEL SHOWS MORE AMPLITUDE DEVELOPING AND POSSIBLY SOME DRYING.
THE PARALLEL VERSION OF THE GFS MODEL IS A BIT MORE LIKE THE ECMWF.
HAVE KEPT OUR CURRENT TRENDS WHICH ARE MORE LIKE THE ECMWF AND THE
PARALLEL GFS MODEL...THOUGH CONFIDENCE IN ANY DETAILS ARE NOT VERY
HIGH AT THIS POINT. TOLLESON

&&

.AVIATION...SCATTERED SHOWERS ARE MOVING OFF TO THE
EAST...ALLOWING CIGS TO IMPROVE ACROSS THE AREA. SOME MVFR AND IFR
REMAINS IN MORE SHELTERED LOCATIONS...BUT THESE SHOULD START TO
IMPROVE BY 21Z. ANOTHER BAND OF SHOWERS WILL MOVE THROUGH THIS
AFTERNOON...WITH CHANCE OF OCCASIONAL MVFR CIGS DURING THESE
SHOWERS. MVFR TO IFR CONDITIONS TO RETURN LATE TONIGHT...MAINLY
ACROSS PORTIONS OF THE SOUTH WILLAMETTE VALLEY.

EASTERLY WIND STILL GUSTING OUT OF THE GORGE TO 25 KT AT KTTD...BUT
SHOULD WIND DOWN TO 10 KT BY 18Z.

KPDX AND APPROACHES...MAINLY VFR TODAY. OCCASIONAL MVFR POSSIBLE
WHEN SHOWERS MOVE THROUGH THIS AFTERNOON.

&&

.MARINE...SMALL CRAFT ADVISORY WINDS WITH GUSTS NEAR 25 KTS TODAY
WILL INCREASE THIS EVENING TO 20 TO 25 KTS GUSTING TO 30 KTS
TONIGHT. WINDS WILL CONTINUE TO RAMP UP FRI MORNING AHEAD OF THE
NEXT FRONTAL SYSTEM...WHICH WILL BE MUCH STRONGER THAN THE LAST
SYSTEM. GALES LOOKING VERY POSSIBLE DURING THE DAY
FRIDAY...AS A COASTAL JET DEVELOPS INITIALLY ALONG THE SOUTH OR
BUILDING NORTHWARD FRIDAY AFTERNOON.

SEAS TODAY WILL STAY AROUND 10 FT...AND WILL START TO BUILD AGAIN
OVERNIGHT TONIGHT WITH THE INCREASING WINDS. SEAS WILL REACH THE
MIDDLE TO UPPER TEENS FRIDAY MORNING...BUILDING TO AROUND 20 FT
MIDDAY FRIDAY. ONCE THE WINDS START TO WEAKEN FRIDAY NIGHT...SEAS
SHOULD DROP FAIRLY QUICKLY...BACK TO 10 TO 12 FT LATE FRIDAY NIGHT
OR EARLY SATURDAY MORNING. SEAS LOOK LIKELY TO REMAIN ABOVE 10 FT
THROUGH THE WEEKEND.

-MCCOY

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...HIGH WIND WATCH FROM FRIDAY MORNING THROUGH FRIDAY EVENING FOR
     CENTRAL OREGON COAST-NORTH OREGON COAST.

     FREEZING RAIN ADVISORY UNTIL 1 PM PST THIS AFTERNOON FOR CENTRAL

     COLUMBIA RIVER GORGE-UPPER HOOD RIVER VALLEY-WESTERN
     COLUMBIA RIVER GORGE.

WA...HIGH WIND WATCH FROM FRIDAY MORNING THROUGH FRIDAY EVENING FOR
     SOUTH WASHINGTON COAST.

     FREEZING RAIN ADVISORY UNTIL 1 PM PST THIS AFTERNOON FOR CENTRAL

     COLUMBIA RIVER GORGE-WESTERN COLUMBIA RIVER GORGE.

PZ...SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 1 PM THIS
AFTERNOON TO 6
     PM PST THIS EVENING.

     SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 AM PST FRIDAY FOR COASTAL
WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 3 PM PST THIS
     AFTERNOON FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE
OR OUT 60 NM.

&&


&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING RAIN ADVISORY UNTIL 1 PM PST THIS AFTERNOON FOR CENTRAL

     COLUMBIA RIVER GORGE-UPPER HOOD RIVER VALLEY-WESTERN
     COLUMBIA RIVER GORGE.

WA...FREEZING RAIN ADVISORY UNTIL 1 PM PST THIS AFTERNOON FOR CENTRAL

     COLUMBIA RIVER GORGE-WESTERN COLUMBIA RIVER GORGE.

PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 7 AM PST THIS MORNING FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT 60
NM.

     SMALL CRAFT ADVISORY FOR WINDS FROM 10 AM THIS MORNING TO 4 AM
     PST FRIDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
     FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 3 PM PST THIS
     AFTERNOON FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
     FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 1 PM
     THIS AFTERNOON TO 6 PM PST THIS EVENING.

&&

$$

INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND

THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.




000
FXUS66 KPQR 201736
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
932 AM PST THU NOV 20 2014

.SYNOPSIS...TWO LOW PRES SYSTEMS ARE MOVING ONTO THE PAC NW TODAY AND
TONIGHT. THE NORTHERN LOW IS MOVING ONSHORE ALONG THE BRITISH
COLUMBIA COAST...WHILE THE SOUTHERN LOW WILL MOVE ONSHORE LATER TODAY
OVER NORTHERN CALIFORNIA AND SOUTHERN OREGON. A BAND OF RAIN
ASSOCIATED WITH THE UPPER LOW IS MOVING THROUGH THIS MORNING...WITH
FREEZING RAIN CONTINUING TO IMPACT THE CENTRAL COLUMBIA RIVER GORGE
AND UPPER HOOD RIVER VALLEY. PRECIPITATION WILL BECOME LESS ORGANIZED
THIS AFTERNOON...BUT SCATTERED SHOWERS WILL REMAIN INTO TONIGHT. A
WELL
ORGANIZED MOIST FRONT WILL BRING HEAVIER RAIN AND STRONG WINDS LATER
FRIDAY AND SATURDAY WITH RAIN AND MOUNTAIN SNOW SHOWERS CONTINUING
THROUGH THE WEEKEND. SNOW LEVELS WILL LIKELY LOWER BELOW THE CASCADE
PASSES BY SATURDAY MORNING.

&&

.SHORT TERM...A SPLIT UPPER LEVEL TROUGH AND TWO ASSOCIATED SURFACE
LOWS ARE AFFECTING THE PAC NW TODAY. THE NORTHERNMOST LOW IS PUSHING
ONSHORE ALONG THE BRITISH COLUMBIA COAST THIS MORNING...WHILE THE
SOUTHERN LOW IS OFF THE SOUTHERN OREGON COAST. A BAND OF MORE
ORGANIZED PRECIPITATION BEING DRIVEN BY THE APPROACHING UPPER TROUGH
AXIS AND SOME ISENTROPIC LIFT AHEAD OF THE SOUTHERN LOW IS APPARENT
ON RADAR OVER THE S WA CASCADES THROUGH THE COLUMBIA RIVER GORGE AND
UPPER HOOD RIVER VALLEY. WITH TEMPS STILL JUST BELOW FREEZING THROUGH
THE CENTRAL GORGE AND HOOD RIVER VALLEY...EXPECT SOME ADDITIONAL
LIGHT ICE ACCUMULATIONS IN THESE AREAS ON TOP OF AROUND A TENTH OF AN
INCH OR MORE THAT SOME AREAS REPORTEDLY RECEIVED OVERNIGHT.  EXPECT
TEMPERATURES THROUGH MUCH OF THE GORGE WILL RISE TO ABOVE FREEZING
THIS AFTERNOON. ALSO EXPECT PRECIPITATION TO TAPER OFF THIS
AFTERNOON...WITH ONLY A FEW SCATTERED SHOWERS REMAINING INTO TONIGHT
AS THE UPPER TROUGH AXIS PUSHES THROUGH. THUS...THINK THE CURRENT
EXPIRATION TIME OF 21Z ON THE FREEZING RAIN ADVISORY LOOKS GOOD.

ANOTHER STRONGER SYSTEM IS ON TAP FOR FRI INTO SAT. BASED ON THE
LATEST MODEL RUNS...IT IS LOOKING INCREASINGLY LIKELY THAT HIGH
WINDS WILL IMPACT THE COAST. THE 12Z NAM AND GFS AND 00Z ECMWF ALL
SUGGEST A CORE OF 60+ KT LOW LEVEL WINDS WILL COME THROUGH FRI
AFTERNOON AND EVENING...ALTHOUGH THE 00Z ECMWF IS STRONGER AND ABOUT
6 HRS SLOWER WITH THE SYSTEM. DESPITE SOME UNCERTAINTY IN THE
OVERALL TIMING...FELT CONFIDENT ENOUGH TO ISSUE A HIGH WIND WATCH
FOR THE COASTAL BEACHES AND HEADLANDS BEGINNING MIDDAY FRI THROUGH
FRI EVENING.

THE MOST DIFFICULT FCST CHALLENGE WITH THE FRI SYSTEM IS THE
POTENTIAL FOR MORE FREEZING RAIN FOR THE UPPER HOOD RIVER VALLEY AND
CENTRAL COLUMBIA GORGE. ALTHOUGH TEMPERATURES THROUGH MOST OF THE
GORGE ARE EXPECTED TO RISE ABOVE FREEZING BY THIS AFTERNOON...THE
FCST MODELS ARE SUGGESTING THAT SOME LIGHT EASTERLY WINDS CONTINUE
INTO FRI AFTERNOON. WITH TEMPS LIKELY REMAINING JUST BELOW FREEZING
ON THE EAST SIDE OF THE CASCADES...AND THE SLIGHT UPSLOPE COMPONENT
TO THE E FLOW INTO THE HOOD RIVER VALLEY...THERE MAY BE A BRIEF
PERIOD OF FREEZING RAIN AT THE ONSET OF PRECIPITATION FRI.
HOWEVER...FAIRLY STRONG WESTERLY FLOW ARRIVES LATER FRI AFTERNOON OR
EARLY EVENING...WHICH SHOULD QUICKLY SWITCH PRECIPITATION OVER TO
RAIN.

OTHER THAN THE COASTAL WINDS AND FREEZING RAIN POTENTIAL...THE MAIN
IMPACT FOR MOST OF THE REGION FROM THIS SYSTEM WILL BE A PERIOD OF
HEAVY RAINS. THE BULK OF THE RAIN SHOULD FALL FRI AFTERNOON AND
EVENING. RIVERS WILL LIKELY MAKE A QUICK UPTURN BUT QPF AMOUNTS AND
DURATION INDICATE ACTION LEVELS ARE NOT LIKELY.

WHILE THE LOWLANDS WILL REMAIN MILD DURING THE UPCOMING PERIOD OF
ACTIVE WEATHER...THE CASCADES WILL BE RECEIVING ACCUMULATING SNOWFALL
DOWN TO THE PASSES AFTER THE FRONT GOES THROUGH OVERNIGHT FRI INTO
SAT. POST FRONTAL OROGRAPHICS LOOK PRETTY GOOD THROUGH THE
WEEKEND...SO EXPECT WE WILL NEED TO LOOK AT ISSUING AN ADVISORY FOR
SNOWFALL AS WE GET CLOSER. PYLE/26

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...SATURDAY NIGHT
THROUGH WEDNESDAY. THE MORE WESTERLY OR ZONAL FLOW THAT SETS UP LATE
IN THE SHORT TERM PERIOD CONTINUES INTO THE LONG TERM PERIOD...WITH
OCCASIONAL RAIN AS DISTURBANCES MOVE THROUGH. SOME RIDGING DEVELOPS
IN THE NORTHEAST PACIFIC EARLY NEXT WEEK...THOUGH THE MODELS VARY ON
HOW MUCH. THE NORMALLY MORE RELIABLE ECMWF MODEL HAS FLATTER RIDGING
WITH MORE OF A DIRTY RIDGE TYPE PATTERN AND DOES BRING SOME
PRECIPITATION INTO THE FORECAST AREA AT TIMES...WHILE THE OPERATIONAL
GFS MODEL SHOWS MORE AMPLITUDE DEVELOPING AND POSSIBLY SOME DRYING.
THE PARALLEL VERSION OF THE GFS MODEL IS A BIT MORE LIKE THE ECMWF.
HAVE KEPT OUR CURRENT TRENDS WHICH ARE MORE LIKE THE ECMWF AND THE
PARALLEL GFS MODEL...THOUGH CONFIDENCE IN ANY DETAILS ARE NOT VERY
HIGH AT THIS POINT. TOLLESON

&&

.AVIATION...SCATTERED SHOWERS ARE MOVING OFF TO THE
EAST...ALLOWING CIGS TO IMPROVE ACROSS THE AREA. SOME MVFR AND IFR
REMAINS IN MORE SHELTERED LOCATIONS...BUT THESE SHOULD START TO
IMPROVE BY 21Z. ANOTHER BAND OF SHOWERS WILL MOVE THROUGH THIS
AFTERNOON...WITH CHANCE OF OCCASIONAL MVFR CIGS DURING THESE
SHOWERS. MVFR TO IFR CONDITIONS TO RETURN LATE TONIGHT...MAINLY
ACROSS PORTIONS OF THE SOUTH WILLAMETTE VALLEY.

EASTERLY WIND STILL GUSTING OUT OF THE GORGE TO 25 KT AT KTTD...BUT
SHOULD WIND DOWN TO 10 KT BY 18Z.

KPDX AND APPROACHES...MAINLY VFR TODAY. OCCASIONAL MVFR POSSIBLE
WHEN SHOWERS MOVE THROUGH THIS AFTERNOON.

&&

.MARINE...SMALL CRAFT ADVISORY WINDS WITH GUSTS NEAR 25 KTS TODAY
WILL INCREASE THIS EVENING TO 20 TO 25 KTS GUSTING TO 30 KTS
TONIGHT. WINDS WILL CONTINUE TO RAMP UP FRI MORNING AHEAD OF THE
NEXT FRONTAL SYSTEM...WHICH WILL BE MUCH STRONGER THAN THE LAST
SYSTEM. GALES LOOKING VERY POSSIBLE DURING THE DAY
FRIDAY...AS A COASTAL JET DEVELOPS INITIALLY ALONG THE SOUTH OR
BUILDING NORTHWARD FRIDAY AFTERNOON.

SEAS TODAY WILL STAY AROUND 10 FT...AND WILL START TO BUILD AGAIN
OVERNIGHT TONIGHT WITH THE INCREASING WINDS. SEAS WILL REACH THE
MIDDLE TO UPPER TEENS FRIDAY MORNING...BUILDING TO AROUND 20 FT
MIDDAY FRIDAY. ONCE THE WINDS START TO WEAKEN FRIDAY NIGHT...SEAS
SHOULD DROP FAIRLY QUICKLY...BACK TO 10 TO 12 FT LATE FRIDAY NIGHT
OR EARLY SATURDAY MORNING. SEAS LOOK LIKELY TO REMAIN ABOVE 10 FT
THROUGH THE WEEKEND.

-MCCOY

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...HIGH WIND WATCH FROM FRIDAY MORNING THROUGH FRIDAY EVENING FOR
     CENTRAL OREGON COAST-NORTH OREGON COAST.

     FREEZING RAIN ADVISORY UNTIL 1 PM PST THIS AFTERNOON FOR CENTRAL

     COLUMBIA RIVER GORGE-UPPER HOOD RIVER VALLEY-WESTERN
     COLUMBIA RIVER GORGE.

WA...HIGH WIND WATCH FROM FRIDAY MORNING THROUGH FRIDAY EVENING FOR
     SOUTH WASHINGTON COAST.

     FREEZING RAIN ADVISORY UNTIL 1 PM PST THIS AFTERNOON FOR CENTRAL

     COLUMBIA RIVER GORGE-WESTERN COLUMBIA RIVER GORGE.

PZ...SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 1 PM THIS
AFTERNOON TO 6
     PM PST THIS EVENING.

     SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 AM PST FRIDAY FOR COASTAL
WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 3 PM PST THIS
     AFTERNOON FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE
OR OUT 60 NM.

&&


&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING RAIN ADVISORY UNTIL 1 PM PST THIS AFTERNOON FOR CENTRAL

     COLUMBIA RIVER GORGE-UPPER HOOD RIVER VALLEY-WESTERN
     COLUMBIA RIVER GORGE.

WA...FREEZING RAIN ADVISORY UNTIL 1 PM PST THIS AFTERNOON FOR CENTRAL

     COLUMBIA RIVER GORGE-WESTERN COLUMBIA RIVER GORGE.

PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 7 AM PST THIS MORNING FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT 60
NM.

     SMALL CRAFT ADVISORY FOR WINDS FROM 10 AM THIS MORNING TO 4 AM
     PST FRIDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
     FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 3 PM PST THIS
     AFTERNOON FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
     FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 1 PM
     THIS AFTERNOON TO 6 PM PST THIS EVENING.

&&

$$

INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND

THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.




000
FXUS66 KPQR 201736
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
932 AM PST THU NOV 20 2014

.SYNOPSIS...TWO LOW PRES SYSTEMS ARE MOVING ONTO THE PAC NW TODAY AND
TONIGHT. THE NORTHERN LOW IS MOVING ONSHORE ALONG THE BRITISH
COLUMBIA COAST...WHILE THE SOUTHERN LOW WILL MOVE ONSHORE LATER TODAY
OVER NORTHERN CALIFORNIA AND SOUTHERN OREGON. A BAND OF RAIN
ASSOCIATED WITH THE UPPER LOW IS MOVING THROUGH THIS MORNING...WITH
FREEZING RAIN CONTINUING TO IMPACT THE CENTRAL COLUMBIA RIVER GORGE
AND UPPER HOOD RIVER VALLEY. PRECIPITATION WILL BECOME LESS ORGANIZED
THIS AFTERNOON...BUT SCATTERED SHOWERS WILL REMAIN INTO TONIGHT. A
WELL
ORGANIZED MOIST FRONT WILL BRING HEAVIER RAIN AND STRONG WINDS LATER
FRIDAY AND SATURDAY WITH RAIN AND MOUNTAIN SNOW SHOWERS CONTINUING
THROUGH THE WEEKEND. SNOW LEVELS WILL LIKELY LOWER BELOW THE CASCADE
PASSES BY SATURDAY MORNING.

&&

.SHORT TERM...A SPLIT UPPER LEVEL TROUGH AND TWO ASSOCIATED SURFACE
LOWS ARE AFFECTING THE PAC NW TODAY. THE NORTHERNMOST LOW IS PUSHING
ONSHORE ALONG THE BRITISH COLUMBIA COAST THIS MORNING...WHILE THE
SOUTHERN LOW IS OFF THE SOUTHERN OREGON COAST. A BAND OF MORE
ORGANIZED PRECIPITATION BEING DRIVEN BY THE APPROACHING UPPER TROUGH
AXIS AND SOME ISENTROPIC LIFT AHEAD OF THE SOUTHERN LOW IS APPARENT
ON RADAR OVER THE S WA CASCADES THROUGH THE COLUMBIA RIVER GORGE AND
UPPER HOOD RIVER VALLEY. WITH TEMPS STILL JUST BELOW FREEZING THROUGH
THE CENTRAL GORGE AND HOOD RIVER VALLEY...EXPECT SOME ADDITIONAL
LIGHT ICE ACCUMULATIONS IN THESE AREAS ON TOP OF AROUND A TENTH OF AN
INCH OR MORE THAT SOME AREAS REPORTEDLY RECEIVED OVERNIGHT.  EXPECT
TEMPERATURES THROUGH MUCH OF THE GORGE WILL RISE TO ABOVE FREEZING
THIS AFTERNOON. ALSO EXPECT PRECIPITATION TO TAPER OFF THIS
AFTERNOON...WITH ONLY A FEW SCATTERED SHOWERS REMAINING INTO TONIGHT
AS THE UPPER TROUGH AXIS PUSHES THROUGH. THUS...THINK THE CURRENT
EXPIRATION TIME OF 21Z ON THE FREEZING RAIN ADVISORY LOOKS GOOD.

ANOTHER STRONGER SYSTEM IS ON TAP FOR FRI INTO SAT. BASED ON THE
LATEST MODEL RUNS...IT IS LOOKING INCREASINGLY LIKELY THAT HIGH
WINDS WILL IMPACT THE COAST. THE 12Z NAM AND GFS AND 00Z ECMWF ALL
SUGGEST A CORE OF 60+ KT LOW LEVEL WINDS WILL COME THROUGH FRI
AFTERNOON AND EVENING...ALTHOUGH THE 00Z ECMWF IS STRONGER AND ABOUT
6 HRS SLOWER WITH THE SYSTEM. DESPITE SOME UNCERTAINTY IN THE
OVERALL TIMING...FELT CONFIDENT ENOUGH TO ISSUE A HIGH WIND WATCH
FOR THE COASTAL BEACHES AND HEADLANDS BEGINNING MIDDAY FRI THROUGH
FRI EVENING.

THE MOST DIFFICULT FCST CHALLENGE WITH THE FRI SYSTEM IS THE
POTENTIAL FOR MORE FREEZING RAIN FOR THE UPPER HOOD RIVER VALLEY AND
CENTRAL COLUMBIA GORGE. ALTHOUGH TEMPERATURES THROUGH MOST OF THE
GORGE ARE EXPECTED TO RISE ABOVE FREEZING BY THIS AFTERNOON...THE
FCST MODELS ARE SUGGESTING THAT SOME LIGHT EASTERLY WINDS CONTINUE
INTO FRI AFTERNOON. WITH TEMPS LIKELY REMAINING JUST BELOW FREEZING
ON THE EAST SIDE OF THE CASCADES...AND THE SLIGHT UPSLOPE COMPONENT
TO THE E FLOW INTO THE HOOD RIVER VALLEY...THERE MAY BE A BRIEF
PERIOD OF FREEZING RAIN AT THE ONSET OF PRECIPITATION FRI.
HOWEVER...FAIRLY STRONG WESTERLY FLOW ARRIVES LATER FRI AFTERNOON OR
EARLY EVENING...WHICH SHOULD QUICKLY SWITCH PRECIPITATION OVER TO
RAIN.

OTHER THAN THE COASTAL WINDS AND FREEZING RAIN POTENTIAL...THE MAIN
IMPACT FOR MOST OF THE REGION FROM THIS SYSTEM WILL BE A PERIOD OF
HEAVY RAINS. THE BULK OF THE RAIN SHOULD FALL FRI AFTERNOON AND
EVENING. RIVERS WILL LIKELY MAKE A QUICK UPTURN BUT QPF AMOUNTS AND
DURATION INDICATE ACTION LEVELS ARE NOT LIKELY.

WHILE THE LOWLANDS WILL REMAIN MILD DURING THE UPCOMING PERIOD OF
ACTIVE WEATHER...THE CASCADES WILL BE RECEIVING ACCUMULATING SNOWFALL
DOWN TO THE PASSES AFTER THE FRONT GOES THROUGH OVERNIGHT FRI INTO
SAT. POST FRONTAL OROGRAPHICS LOOK PRETTY GOOD THROUGH THE
WEEKEND...SO EXPECT WE WILL NEED TO LOOK AT ISSUING AN ADVISORY FOR
SNOWFALL AS WE GET CLOSER. PYLE/26

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...SATURDAY NIGHT
THROUGH WEDNESDAY. THE MORE WESTERLY OR ZONAL FLOW THAT SETS UP LATE
IN THE SHORT TERM PERIOD CONTINUES INTO THE LONG TERM PERIOD...WITH
OCCASIONAL RAIN AS DISTURBANCES MOVE THROUGH. SOME RIDGING DEVELOPS
IN THE NORTHEAST PACIFIC EARLY NEXT WEEK...THOUGH THE MODELS VARY ON
HOW MUCH. THE NORMALLY MORE RELIABLE ECMWF MODEL HAS FLATTER RIDGING
WITH MORE OF A DIRTY RIDGE TYPE PATTERN AND DOES BRING SOME
PRECIPITATION INTO THE FORECAST AREA AT TIMES...WHILE THE OPERATIONAL
GFS MODEL SHOWS MORE AMPLITUDE DEVELOPING AND POSSIBLY SOME DRYING.
THE PARALLEL VERSION OF THE GFS MODEL IS A BIT MORE LIKE THE ECMWF.
HAVE KEPT OUR CURRENT TRENDS WHICH ARE MORE LIKE THE ECMWF AND THE
PARALLEL GFS MODEL...THOUGH CONFIDENCE IN ANY DETAILS ARE NOT VERY
HIGH AT THIS POINT. TOLLESON

&&

.AVIATION...SCATTERED SHOWERS ARE MOVING OFF TO THE
EAST...ALLOWING CIGS TO IMPROVE ACROSS THE AREA. SOME MVFR AND IFR
REMAINS IN MORE SHELTERED LOCATIONS...BUT THESE SHOULD START TO
IMPROVE BY 21Z. ANOTHER BAND OF SHOWERS WILL MOVE THROUGH THIS
AFTERNOON...WITH CHANCE OF OCCASIONAL MVFR CIGS DURING THESE
SHOWERS. MVFR TO IFR CONDITIONS TO RETURN LATE TONIGHT...MAINLY
ACROSS PORTIONS OF THE SOUTH WILLAMETTE VALLEY.

EASTERLY WIND STILL GUSTING OUT OF THE GORGE TO 25 KT AT KTTD...BUT
SHOULD WIND DOWN TO 10 KT BY 18Z.

KPDX AND APPROACHES...MAINLY VFR TODAY. OCCASIONAL MVFR POSSIBLE
WHEN SHOWERS MOVE THROUGH THIS AFTERNOON.

&&

.MARINE...SMALL CRAFT ADVISORY WINDS WITH GUSTS NEAR 25 KTS TODAY
WILL INCREASE THIS EVENING TO 20 TO 25 KTS GUSTING TO 30 KTS
TONIGHT. WINDS WILL CONTINUE TO RAMP UP FRI MORNING AHEAD OF THE
NEXT FRONTAL SYSTEM...WHICH WILL BE MUCH STRONGER THAN THE LAST
SYSTEM. GALES LOOKING VERY POSSIBLE DURING THE DAY
FRIDAY...AS A COASTAL JET DEVELOPS INITIALLY ALONG THE SOUTH OR
BUILDING NORTHWARD FRIDAY AFTERNOON.

SEAS TODAY WILL STAY AROUND 10 FT...AND WILL START TO BUILD AGAIN
OVERNIGHT TONIGHT WITH THE INCREASING WINDS. SEAS WILL REACH THE
MIDDLE TO UPPER TEENS FRIDAY MORNING...BUILDING TO AROUND 20 FT
MIDDAY FRIDAY. ONCE THE WINDS START TO WEAKEN FRIDAY NIGHT...SEAS
SHOULD DROP FAIRLY QUICKLY...BACK TO 10 TO 12 FT LATE FRIDAY NIGHT
OR EARLY SATURDAY MORNING. SEAS LOOK LIKELY TO REMAIN ABOVE 10 FT
THROUGH THE WEEKEND.

-MCCOY

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...HIGH WIND WATCH FROM FRIDAY MORNING THROUGH FRIDAY EVENING FOR
     CENTRAL OREGON COAST-NORTH OREGON COAST.

     FREEZING RAIN ADVISORY UNTIL 1 PM PST THIS AFTERNOON FOR CENTRAL

     COLUMBIA RIVER GORGE-UPPER HOOD RIVER VALLEY-WESTERN
     COLUMBIA RIVER GORGE.

WA...HIGH WIND WATCH FROM FRIDAY MORNING THROUGH FRIDAY EVENING FOR
     SOUTH WASHINGTON COAST.

     FREEZING RAIN ADVISORY UNTIL 1 PM PST THIS AFTERNOON FOR CENTRAL

     COLUMBIA RIVER GORGE-WESTERN COLUMBIA RIVER GORGE.

PZ...SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 1 PM THIS
AFTERNOON TO 6
     PM PST THIS EVENING.

     SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 AM PST FRIDAY FOR COASTAL
WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 3 PM PST THIS
     AFTERNOON FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE
OR OUT 60 NM.

&&


&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING RAIN ADVISORY UNTIL 1 PM PST THIS AFTERNOON FOR CENTRAL

     COLUMBIA RIVER GORGE-UPPER HOOD RIVER VALLEY-WESTERN
     COLUMBIA RIVER GORGE.

WA...FREEZING RAIN ADVISORY UNTIL 1 PM PST THIS AFTERNOON FOR CENTRAL

     COLUMBIA RIVER GORGE-WESTERN COLUMBIA RIVER GORGE.

PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 7 AM PST THIS MORNING FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT 60
NM.

     SMALL CRAFT ADVISORY FOR WINDS FROM 10 AM THIS MORNING TO 4 AM
     PST FRIDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
     FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 3 PM PST THIS
     AFTERNOON FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
     FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 1 PM
     THIS AFTERNOON TO 6 PM PST THIS EVENING.

&&

$$

INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND

THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.




000
FXUS66 KSEW 201716
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
900 AM PST THU NOV 20 2014

.SYNOPSIS...WEAK LOW PRESSURE ALOFT WILL PREVAIL OVER THE REGION
TODAY FOR SCATTERED SHOWERS. THE AREA WILL BE BETWEEN SYSTEMS
TONIGHT. A STRONGER PACIFIC STORM WILL IMPACT THE REGION ON FRIDAY
FOR LOCALLY HEAVY RAIN AND GUSTY WINDS...ALONG WITH THE POTENTIAL
FOR DECENT SNOWFALL IN THE MOUNTAINS. THE WEATHER PATTERN WILL
REMAIN WET AND UNSETTLED THIS WEEKEND.

&&

.SHORT TERM...AS A COUPLE OF WEAK LOW PRESSURE SYSTEMS MOVE INLAND
TO OUR NORTH AND SOUTH...RECENT MODEL SOLUTIONS SHOW SHOWERS
LINGERING MORE TODAY AND TONIGHT THAN PREVIOUSLY THOUGHT. RIGHT NOW
THE FORECAST FOR THE LOWLANDS SHOWS TONIGHT MAINLY DRY...BUT MAY
BUMP UP THE POPS AFTER REEVALUATING LATER TODAY.

A STRONGER PACIFIC STORM WILL IMPACT THE REGION ON FRI FOR LOCALLY
HEAVY RAIN AND GUSTY WINDS IN THE FAVORED AREAS...COAST AND NORTH
INTERIOR. A WIND ADVISORY WILL LIKELY BE NEEDED FOR THESE AREAS FOR
LATE FRI MORNING THROUGH AT LEAST FRI AFTERNOON.

IT LOOKS LIKE THE CENTRAL AND NORTH CASCADES ABOVE 4000 FEET WILL
RECEIVE WINTER WEATHER ADVISORY CRITERIA SNOWFALL AMOUNTS OR AMOUNTS
IN THE 6 TO 11 INCH RANGE FRI NIGHT...ALTHOUGH IT IS POSSIBLE THAT
THE MOUNT BAKER SKI AREA COULD RECEIVE ABOUT A FOOT OF SNOW.

THE COLD FRONT WILL SWEEP ACROSS THE CWA FRI NIGHT. EXPECT THE
UPPER TROF TO MOVE ACROSS THE REGION EARLY SATURDAY. THE AIR MASS
WILL REMAIN UNSTABLE ENOUGH FOR PLENTY OF SHOWERS ON SATURDAY. IN
ADDITION...A PUGET SOUND CONVERGENCE ZONE COULD DEVELOP IN ITS
FAVORED LOCATION...NEAR THE KING/SNOHOMISH COUNTY BORDER...IN THE
WAKE OF THE COLD FRONT. JSMITH

.LONG TERM...ANOTHER LOW PRESSURE SYSTEM WILL MOVE ACROSS THE
PACIFIC NORTHWEST ON SUNDAY...THUS POPS WERE BUMPED UP TO
CATEGORICAL. MONDAY AND BEYOND...BOTH THE GFS AND ECMWF SHOW
MOISTURE BEING TRANSPORTED TO THE PACIFIC NW VIA THE JET
STREAM...HOWEVER THE GFS HAS THE MOISTURE HITTING BC AND US STAYING
DRY WITH A RIDGE PATTERN...WHEREAS THE ECMWF HAS A WETTER SOLUTION
FOR US WITH THE MOISTURE HITTING US DIRECTLY. THEREFORE MUCH
UNCERTAINTY EXISTS IN THE FORECAST FOR EARLY NEXT WEEK. JSMITH

&&

.HYDROLOGY...RIVER FLOODING IS NOT EXPECTED THE NEXT 7 DAYS.

&&

.AVIATION...A WEAK UPPER LEVEL TROUGH WILL REMAIN OVER W WA TODAY IN
THE WAKE OF LAST NIGHTS COLD FRONT. RESIDUAL LOW LEVEL MOISTURE WILL
KEEP CIGS BKN030-060 THROUGH TODAY...WITH SPOTTY MVFR CIGS
BKN015-030 MAINLY AROUND WEAK SHOWERS THROUGH ABOUT 00Z/5 PM. THE
AIR MASS IS MAINLY STABLE.

INCREASING W FLOW ALOFT WILL DRIVE AN APPROACHING FRONTAL
SYSTEM...ALONG 140W AT 1630Z/830 AM...ACROSS W WA FRIDAY AND FRIDAY
NIGHT. GUSTY WINDS ARE EXPECTED ALONG THE COAST AND PARTS OF THE N
INTERIOR ALONG WITH A RETURN OF MVFR CONDITIONS THROUGHOUT THE AREA.

KSEA...MAINLY VFR TODAY WITH CIGS BKN040-060. COULD SEE SOME BRIEF
CIGS BKN020-030 IF A ROGUE SHOWER CROSSES THE AREA. VISIBILITY
UNRESTRICTED. SURFACE WINDS WILL REMAIN S-SE 4-8 KT THROUGH THIS
EVENING. KAM

&&

.MARINE...THE SURFACE LOW FROM LAST NIGHTS COLD FRONT WILL REMAIN
ALONG THE B.C. COAST TODAY...MAINTAINING S FLOW ACROSS WA WATERS.
WINDS ARE ALREADY BELOW SCA LEVELS AND THE EXISTING SCA WILL BE
ALLOWED TO EXPIRE AT 10 AM.

THE NEXT FRONTAL SYSTEM OVER THE NE PACIFIC ALONG 140W AT 1630Z/830
AM WILL APPROACH THE REGION TONIGHT THE MOVE ACROSS THE AREA
FRIDAY/FRIDAY NIGHT. MODELS REMAIN FAIRLY CONSISTENT IN SHOWING
GALES OVER THE COASTAL WATERS STARTING FRIDAY AFTERNOON AND THE
USUAL SE EXPOSED AREAS OF THE NORTH INTERIOR WATERS STARTING LATE
FRIDAY AFTERNOON/FRIDAY EVENING.

WESTERLY FLOW ALOFT OVER THE NORTHEAST PACIFIC SATURDAY THROUGH
MONDAY WILL BRING SEVERAL WEAKER SURFACE TROUGHS ACROSS THE AREA.
SWELLS IN THE 15-20 FOOT RANGE ARE FORECAST TO REACH THE COAST
SUNDAY. KAM

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS EXCEPT CENTRAL STRAIT AND PUGET
     SOUND THIS MORNING.
     GALE WARNING COAST FRIDAY AFTERNOON AND EVENING.
     GALE WATCH EAST ENTRANCE AND NORTHERN INLAND WATERS FRIDAY
     AFTERNOON AND EVENING.
     SMALL CRAFT ADVISORY FOR ROUGH GRAYS HARBOR BAR.

&&

$$

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000
FXUS66 KOTX 201320
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
520 AM PST THU NOV 20 2014

.SYNOPSIS...
A weak weather system will arrive late tonight into Thursday with
the potential for a light wintry mix of rain...snow...and freezing
rain. A stronger, wetter and windier weather system will arrive
Friday persisting into the weekend with heavy snow amounts
possible over the mountains. The weather pattern will remain
active through the middle of next week.



&&

.DISCUSSION...

...Pockets of freezing rain possible this morning over the lower
Columbia Basin and portions of the Washington Palouse...

Today and tonight ...The ridge of the past week and a half is
becoming a relic of the past as disturbance number one (of many)
is currently passing through western Washington with its sights
set on the Inland Northwest. This disturbance is comprised of an
elongating band of moisture extending from a weak upper level low
just west of Vancouver Island southeast into in southwest Idaho.
Associated with this band of moisture was a weakening warm front
which will provide the focus for the weather today. Models have
remained rather consistent in taking this front from its current
position over south-central Washington northeast across the
remainder of eastern Washington and north Idaho today. The trend
of slowing the front continues...and now it looks like the front
won`t arrive into the northern tip of Idaho until around midday.

Forcing and lifting along the front looks rather weak...and it will
likely continue to diminish as it treks northeastward today.
Nonetheless...with a modified arctic air mass still firmly
entrenched over most of the region...it won`t take much lifting to
generate precipitation as the isentropic surfaces look rather
steep. That suggests most of the region will be subject to
precipitation today...but the question is what will it fall as.
This remains an exceedingly tricky forecast element. Model cross-
sections and 0-4km max wet-bulb temperatures continue to show an
elevated wedge of above freezing air over the extreme southern
portion of our forecast area. This encompasses the area generally
south of a line from Wenatchee to Moses Lake...then Pullman. Any
locations south of this line will be subject to light freezing
rain (with a small chance of sleet)...through this morning.
Meanwhile anything north will generally see snow. Again amounts
will be fairly light. Through the end of the day most locations
will see an tenth of an inch of precipitation or less. Snow
amounts will reflect this light precipitation with locations
generally seeing less than an inch. As for the freezing
rain...amounts will also be light...however any freezing rain can
result in potential travel difficulties. The potential for travel
problems will generally be confined to the morning hours as any
diurnal heating should bring road temperatures above freezing by
midday. Additionally...most of the precipitation threat also move
north and east of this elevated warm layer as well.

The front is expected to dissipate rapidly during the
evening...but that won`t be the end of the precipitation.
Initially upslope flow and residual frontal moisture will keep the
light snow falling over north Idaho...however things will
intensify somewhat overnight. This next round of precipitation
will be delivered care of the shortwave trough off of Vancouver
Island tracking through southern British Columbia overnight. The
lifting associated with this feature will not be strong...however
the atmosphere below 650 mbs or roughly 10k feet will become
saturated overnight. Renewed isentropic ascent...especially for
locations north of Highway 2 (in Washington) and I-90 (in
Idaho)...should result in a second round of precipitation. The
warm layer will surge a little farther north as well. By
morning...a shallow elevated melting layer could move as far north
as a Lake Chelan to Spokane line. This will be on the southern
edge of the next round of precipitation so there`s a small chance
of more freezing rain...however by that time...surface wet-bulb
temperatures are expected to near or exceed freezing...so main
precipitation would be rain or a rain snow mix for the Spokane
area and southeast sections of the Columbia Basin. For locations
over the northwest portion of the Basin...including Grand
Coulee...Wilbur...and Davenport there will be a small chance of
freezing rain. Confidence is not high however...as so much is
dependent on what happens today in terms of surface warming. If a
location gets above freezing today...it will likely remain that
way overnight as well. fx


...MODERATE TO HEAVY MOUNTAIN SNOW POSSIBLE LATE FRIDAY INTO
SATURDAY...

Friday through Monday: A series of systems slide across the
Inland NW, with several opportunities for rain and snow. First
early Friday the next system will be approaching. There will be a
threat of light snow or freezing rain/freezing drizzle across the
Upper Columbia Basin through northeast WA and north ID due to some
isentropic lift and low level moisture. The moisture is deepest
below about 650 to 700 mbs, below the core of the snow growth
zone. So this suggest the potential for a mixture of snow,
freezing rain or freezing drizzle, and rain as the precipitation
type. So we could be looking for some slick conditions along the
I-90/US-2/US-95 corridor in the morning.

Then Friday afternoon into Friday evening deepening isentropic
ascent and moisture noses across the Cascades into eastern WA and
north ID with the warm front. This will lead to increasing
precipitation from west to east, so that by early evening most of
Washington will be enveloped by it and by middle to late evening
much of Idaho will be too. Overnight the associated cold front
slips east of the Cascades, leading to dwindling precipitation in
the lee of the Cascades and western Columbia Basin. By late
Saturday morning to afternoon the highest threat briefly retreats
to the mountains, with winds becoming breezy to locally windy.
With the evolution discussed, the next questions surround snow
levels and precipitation amounts.

* Snow levels: The location of the snow hasn`t changed much from
  previous thinking. Based on wet-bulb zero heights, snow levels
  from Friday afternoon through Friday night will be around
  3000-4000 feet across the Cascades and northern mountains and
  4000 to 5000 feet southeast. However colder air trapped near the
  Cascades in the low level southeast flow will keep snow levels
  1500-3000 feet. This includes places in the lee of the Cascades,
  including the Okanogan Valley and Highlands through the
  Waterville Plateau and Wenatchee area. So the Cascades and areas
  the remaining mountain areas above 3000 to 4000 feet (except for
  the Blue Mountains where snow levels look too high to have much
  impact in the populated areas). Winter storm watches
  remain place for the Cascades and in the north WA and ID
  mountains above 4000 feet. We will monitor the potential need
  for advisories outside of the mountains, in the hills around the
  Okanogan Valley and Waterville Plateau and Wenatchee area.
  However accumulations may be limited if milder air is able to
  move in or precipitation amounts are not as high as expected.
  Behind the cold front going into Saturday afternoon snow levels
  drop to between 2500-3000 feet. So this means any lingering
  showers may be a mix of rain and snow, including as far south as
  the I-90 corridor. However by then the better precipitation
  threat starts that shift into the mountains.

* Precipitation amounts: Regional PWATs rise to between 0.45 to
  0.75 inches (or 130 to 200% of normal). So this is a juicy
  system and all models generate decent precipitation amounts. In
  the 24-hour period between Friday afternoon and Saturday
  afternoon models generate between 0.30 to 0.60 inches of liquid
  precipitation across a good portion of the Inland NW, with lower
  amounts over the deeper Columbia Basin and higher amounts
  between 0.75 to 1.0 inch in the mountains. For areas the
  mountain snow this could translate to between 6 to 12 inches,
  while the lower elevations closer to the Cascades could see
  anywhere from a trace to a couple inches or so. These numbers,
  especially the lower elevation ones, will continue to be fine-
  tuned.

From Saturday evening into Sunday morning a secondary disturbance
slips by, renewing the precipitation threat outside of the
mountains. However precipitation amount as compared to Friday
night, look light. A third and more organized system comes in
sometime between Sunday and Monday morning. This taps some
subtropical moisture, but it is not as robust as the Friday night
system. Still models generate a modest precipitation threat across
all but the lee of the Cascades and deeper Basin. When and where
this develops is where model disagreement lingers. Most models
start precipitation early Sunday near Cascades. Yet farther east
some start it up through southeast WA and the central Panhandle in
the morning and others hold it off until afternoon. Chances remain
high outside of the lee of the Cascades and deeper Columbia Basin
through the evening, then dissipate overnight into Monday. Still
the leading edge of a fourth system, a warm front, approaches from
the west Monday afternoon. Whether moisture is deep enough to
allow precipitation to redevelop or just thickening clouds is even
less agreed upon. Chances will remain high near the Cascades and
lower elsewhere. As for snow levels through the period from
Saturday night through Monday, they waver between about 1500 and
3000 feet during the night and early morning hours and 2000 and
4000 feet during the day and early evening hours. The lowest of
those lay toward the northeast WA and north ID. This translates to
the potential for snow down to valley floors, especially at night,
and perhaps some light accumulations in the valleys. This includes
potentially the I-90 corridor, especially east of Ritzville and
the higher Palouse, as well as areas from the Waterville Plateau
north. /J. Cote`

Monday Night through Thursday: Pattern looks to remain active
early in the week as the moist northwesterly flow continues to
influence our weather. Exactly how long we remain active is up for
debate amongst the models at this point. The GFS brings an
offshore ridge near the west coast shifting the majority of the
atmospheric dynamics and moisture to the north ultimately leading
to a drier forecast. The ECMWF with support from the Canadian
model keeps the ridge further offshore and the opportunity for
precipitation alive much later into the week. At this point I have
leaned toward the Euro due to performance up to this point with
winter systems and kept POPs above climo through Wednesday. Along
with precip into the middle of the week, the Euro also brings
another round of cold continental polar air into the region
starting Wednesday sending our temperatures back below normal. In
turn the temperatures were trended down, but not yet to the full
extent of the ECMWF as I want just a bit more confidence. The
polar airmass is also quite dry so once the modified polar front
passes Wednesday, POPs drop off as well. Snow levels with the
precipitation in the extended forecast once again looks to sit
above most valley floors minus the far northern ones leading to
mainly a valley rain/mountain snow event. Higher benches such as
the West Plains, Upper Columbia Basin, etc. could see some snow
mix in overnight as our diurnal swings bottoms out. While this
forecast leaned more towards the Euro, model trends will have to
be closely monitored to better pin down the details as we near
this timeframe. /Fliehman

&&

.AVIATION...
12Z TAFS: A weak frontal boundary will continue to lift to the
northeast this morning potentially impacting all forecast sites.
The threat will exit MWH and EAT by 15z and the other sites
between 17-19z. While vsbys and cigs will generally be in the VFR
category...brief MVFR conditions will be possible but not worth
mentioning in forecast. The most difficult part of the forecast is
what will the precipitation fall as. Based on elevated melting
layer and temperatures near or below freezing at all sites...a
winter mix is expected with the best chances of freezing rain
expected for PUW and MWH. Confidence is low though as this is a
very complex situation. The front will exit the area...with dry
weather for most sites afterwords. Later tonight another round of
precipitation arrives late tonight (after 08z) and this will
mainly impact GEG- SFF- COE. Suspect this round will mainly be
rain...but that is far from certain. fx

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        34  31  38  34  42  29 /  50  30  40 100  60  30
Coeur d`Alene  34  32  40  33  41  31 /  70  40  50 100  70  30
Pullman        39  29  42  35  42  32 /  60  10  20 100  70  30
Lewiston       40  31  45  39  47  35 /  80  10  10  80  50  30
Colville       34  26  38  34  43  26 /  50  40  70 100  40  30
Sandpoint      34  30  39  33  41  29 /  60  70  70 100  70  30
Kellogg        34  31  39  32  39  32 /  90  60  60 100  90  40
Moses Lake     35  21  37  31  47  28 /  60   0  70 100  30  20
Wenatchee      39  28  36  31  45  31 /  70   0  80 100  20  30
Omak           36  27  37  30  43  27 /  50  20  90 100  20  30

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Air Stagnation Advisory until Noon PST Friday for Central
     Panhandle Mountains-Coeur d`Alene Area-Idaho Palouse-
     Northern Panhandle.

     Winter Storm Watch from Friday afternoon through Saturday
     afternoon for Central Panhandle Mountains-Northern
     Panhandle.

WA...Air Stagnation Advisory until Noon PST Friday for East Slopes
     Northern Cascades-Lower Garfield and Asotin Counties-Moses
     Lake Area-Northeast Mountains-Okanogan Highlands-Spokane
     Area-Upper Columbia Basin-Washington Palouse-Waterville
     Plateau-Wenatchee Area.

     Winter Storm Watch from Friday afternoon through Saturday
     afternoon for Northeast Mountains-Okanogan Highlands.

     Winter Storm Watch from Friday morning through late Friday night
     for East Slopes Northern Cascades.

&&

$$




000
FXUS66 KOTX 201320
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
520 AM PST THU NOV 20 2014

.SYNOPSIS...
A weak weather system will arrive late tonight into Thursday with
the potential for a light wintry mix of rain...snow...and freezing
rain. A stronger, wetter and windier weather system will arrive
Friday persisting into the weekend with heavy snow amounts
possible over the mountains. The weather pattern will remain
active through the middle of next week.



&&

.DISCUSSION...

...Pockets of freezing rain possible this morning over the lower
Columbia Basin and portions of the Washington Palouse...

Today and tonight ...The ridge of the past week and a half is
becoming a relic of the past as disturbance number one (of many)
is currently passing through western Washington with its sights
set on the Inland Northwest. This disturbance is comprised of an
elongating band of moisture extending from a weak upper level low
just west of Vancouver Island southeast into in southwest Idaho.
Associated with this band of moisture was a weakening warm front
which will provide the focus for the weather today. Models have
remained rather consistent in taking this front from its current
position over south-central Washington northeast across the
remainder of eastern Washington and north Idaho today. The trend
of slowing the front continues...and now it looks like the front
won`t arrive into the northern tip of Idaho until around midday.

Forcing and lifting along the front looks rather weak...and it will
likely continue to diminish as it treks northeastward today.
Nonetheless...with a modified arctic air mass still firmly
entrenched over most of the region...it won`t take much lifting to
generate precipitation as the isentropic surfaces look rather
steep. That suggests most of the region will be subject to
precipitation today...but the question is what will it fall as.
This remains an exceedingly tricky forecast element. Model cross-
sections and 0-4km max wet-bulb temperatures continue to show an
elevated wedge of above freezing air over the extreme southern
portion of our forecast area. This encompasses the area generally
south of a line from Wenatchee to Moses Lake...then Pullman. Any
locations south of this line will be subject to light freezing
rain (with a small chance of sleet)...through this morning.
Meanwhile anything north will generally see snow. Again amounts
will be fairly light. Through the end of the day most locations
will see an tenth of an inch of precipitation or less. Snow
amounts will reflect this light precipitation with locations
generally seeing less than an inch. As for the freezing
rain...amounts will also be light...however any freezing rain can
result in potential travel difficulties. The potential for travel
problems will generally be confined to the morning hours as any
diurnal heating should bring road temperatures above freezing by
midday. Additionally...most of the precipitation threat also move
north and east of this elevated warm layer as well.

The front is expected to dissipate rapidly during the
evening...but that won`t be the end of the precipitation.
Initially upslope flow and residual frontal moisture will keep the
light snow falling over north Idaho...however things will
intensify somewhat overnight. This next round of precipitation
will be delivered care of the shortwave trough off of Vancouver
Island tracking through southern British Columbia overnight. The
lifting associated with this feature will not be strong...however
the atmosphere below 650 mbs or roughly 10k feet will become
saturated overnight. Renewed isentropic ascent...especially for
locations north of Highway 2 (in Washington) and I-90 (in
Idaho)...should result in a second round of precipitation. The
warm layer will surge a little farther north as well. By
morning...a shallow elevated melting layer could move as far north
as a Lake Chelan to Spokane line. This will be on the southern
edge of the next round of precipitation so there`s a small chance
of more freezing rain...however by that time...surface wet-bulb
temperatures are expected to near or exceed freezing...so main
precipitation would be rain or a rain snow mix for the Spokane
area and southeast sections of the Columbia Basin. For locations
over the northwest portion of the Basin...including Grand
Coulee...Wilbur...and Davenport there will be a small chance of
freezing rain. Confidence is not high however...as so much is
dependent on what happens today in terms of surface warming. If a
location gets above freezing today...it will likely remain that
way overnight as well. fx


...MODERATE TO HEAVY MOUNTAIN SNOW POSSIBLE LATE FRIDAY INTO
SATURDAY...

Friday through Monday: A series of systems slide across the
Inland NW, with several opportunities for rain and snow. First
early Friday the next system will be approaching. There will be a
threat of light snow or freezing rain/freezing drizzle across the
Upper Columbia Basin through northeast WA and north ID due to some
isentropic lift and low level moisture. The moisture is deepest
below about 650 to 700 mbs, below the core of the snow growth
zone. So this suggest the potential for a mixture of snow,
freezing rain or freezing drizzle, and rain as the precipitation
type. So we could be looking for some slick conditions along the
I-90/US-2/US-95 corridor in the morning.

Then Friday afternoon into Friday evening deepening isentropic
ascent and moisture noses across the Cascades into eastern WA and
north ID with the warm front. This will lead to increasing
precipitation from west to east, so that by early evening most of
Washington will be enveloped by it and by middle to late evening
much of Idaho will be too. Overnight the associated cold front
slips east of the Cascades, leading to dwindling precipitation in
the lee of the Cascades and western Columbia Basin. By late
Saturday morning to afternoon the highest threat briefly retreats
to the mountains, with winds becoming breezy to locally windy.
With the evolution discussed, the next questions surround snow
levels and precipitation amounts.

* Snow levels: The location of the snow hasn`t changed much from
  previous thinking. Based on wet-bulb zero heights, snow levels
  from Friday afternoon through Friday night will be around
  3000-4000 feet across the Cascades and northern mountains and
  4000 to 5000 feet southeast. However colder air trapped near the
  Cascades in the low level southeast flow will keep snow levels
  1500-3000 feet. This includes places in the lee of the Cascades,
  including the Okanogan Valley and Highlands through the
  Waterville Plateau and Wenatchee area. So the Cascades and areas
  the remaining mountain areas above 3000 to 4000 feet (except for
  the Blue Mountains where snow levels look too high to have much
  impact in the populated areas). Winter storm watches
  remain place for the Cascades and in the north WA and ID
  mountains above 4000 feet. We will monitor the potential need
  for advisories outside of the mountains, in the hills around the
  Okanogan Valley and Waterville Plateau and Wenatchee area.
  However accumulations may be limited if milder air is able to
  move in or precipitation amounts are not as high as expected.
  Behind the cold front going into Saturday afternoon snow levels
  drop to between 2500-3000 feet. So this means any lingering
  showers may be a mix of rain and snow, including as far south as
  the I-90 corridor. However by then the better precipitation
  threat starts that shift into the mountains.

* Precipitation amounts: Regional PWATs rise to between 0.45 to
  0.75 inches (or 130 to 200% of normal). So this is a juicy
  system and all models generate decent precipitation amounts. In
  the 24-hour period between Friday afternoon and Saturday
  afternoon models generate between 0.30 to 0.60 inches of liquid
  precipitation across a good portion of the Inland NW, with lower
  amounts over the deeper Columbia Basin and higher amounts
  between 0.75 to 1.0 inch in the mountains. For areas the
  mountain snow this could translate to between 6 to 12 inches,
  while the lower elevations closer to the Cascades could see
  anywhere from a trace to a couple inches or so. These numbers,
  especially the lower elevation ones, will continue to be fine-
  tuned.

From Saturday evening into Sunday morning a secondary disturbance
slips by, renewing the precipitation threat outside of the
mountains. However precipitation amount as compared to Friday
night, look light. A third and more organized system comes in
sometime between Sunday and Monday morning. This taps some
subtropical moisture, but it is not as robust as the Friday night
system. Still models generate a modest precipitation threat across
all but the lee of the Cascades and deeper Basin. When and where
this develops is where model disagreement lingers. Most models
start precipitation early Sunday near Cascades. Yet farther east
some start it up through southeast WA and the central Panhandle in
the morning and others hold it off until afternoon. Chances remain
high outside of the lee of the Cascades and deeper Columbia Basin
through the evening, then dissipate overnight into Monday. Still
the leading edge of a fourth system, a warm front, approaches from
the west Monday afternoon. Whether moisture is deep enough to
allow precipitation to redevelop or just thickening clouds is even
less agreed upon. Chances will remain high near the Cascades and
lower elsewhere. As for snow levels through the period from
Saturday night through Monday, they waver between about 1500 and
3000 feet during the night and early morning hours and 2000 and
4000 feet during the day and early evening hours. The lowest of
those lay toward the northeast WA and north ID. This translates to
the potential for snow down to valley floors, especially at night,
and perhaps some light accumulations in the valleys. This includes
potentially the I-90 corridor, especially east of Ritzville and
the higher Palouse, as well as areas from the Waterville Plateau
north. /J. Cote`

Monday Night through Thursday: Pattern looks to remain active
early in the week as the moist northwesterly flow continues to
influence our weather. Exactly how long we remain active is up for
debate amongst the models at this point. The GFS brings an
offshore ridge near the west coast shifting the majority of the
atmospheric dynamics and moisture to the north ultimately leading
to a drier forecast. The ECMWF with support from the Canadian
model keeps the ridge further offshore and the opportunity for
precipitation alive much later into the week. At this point I have
leaned toward the Euro due to performance up to this point with
winter systems and kept POPs above climo through Wednesday. Along
with precip into the middle of the week, the Euro also brings
another round of cold continental polar air into the region
starting Wednesday sending our temperatures back below normal. In
turn the temperatures were trended down, but not yet to the full
extent of the ECMWF as I want just a bit more confidence. The
polar airmass is also quite dry so once the modified polar front
passes Wednesday, POPs drop off as well. Snow levels with the
precipitation in the extended forecast once again looks to sit
above most valley floors minus the far northern ones leading to
mainly a valley rain/mountain snow event. Higher benches such as
the West Plains, Upper Columbia Basin, etc. could see some snow
mix in overnight as our diurnal swings bottoms out. While this
forecast leaned more towards the Euro, model trends will have to
be closely monitored to better pin down the details as we near
this timeframe. /Fliehman

&&

.AVIATION...
12Z TAFS: A weak frontal boundary will continue to lift to the
northeast this morning potentially impacting all forecast sites.
The threat will exit MWH and EAT by 15z and the other sites
between 17-19z. While vsbys and cigs will generally be in the VFR
category...brief MVFR conditions will be possible but not worth
mentioning in forecast. The most difficult part of the forecast is
what will the precipitation fall as. Based on elevated melting
layer and temperatures near or below freezing at all sites...a
winter mix is expected with the best chances of freezing rain
expected for PUW and MWH. Confidence is low though as this is a
very complex situation. The front will exit the area...with dry
weather for most sites afterwords. Later tonight another round of
precipitation arrives late tonight (after 08z) and this will
mainly impact GEG- SFF- COE. Suspect this round will mainly be
rain...but that is far from certain. fx

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        34  31  38  34  42  29 /  50  30  40 100  60  30
Coeur d`Alene  34  32  40  33  41  31 /  70  40  50 100  70  30
Pullman        39  29  42  35  42  32 /  60  10  20 100  70  30
Lewiston       40  31  45  39  47  35 /  80  10  10  80  50  30
Colville       34  26  38  34  43  26 /  50  40  70 100  40  30
Sandpoint      34  30  39  33  41  29 /  60  70  70 100  70  30
Kellogg        34  31  39  32  39  32 /  90  60  60 100  90  40
Moses Lake     35  21  37  31  47  28 /  60   0  70 100  30  20
Wenatchee      39  28  36  31  45  31 /  70   0  80 100  20  30
Omak           36  27  37  30  43  27 /  50  20  90 100  20  30

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Air Stagnation Advisory until Noon PST Friday for Central
     Panhandle Mountains-Coeur d`Alene Area-Idaho Palouse-
     Northern Panhandle.

     Winter Storm Watch from Friday afternoon through Saturday
     afternoon for Central Panhandle Mountains-Northern
     Panhandle.

WA...Air Stagnation Advisory until Noon PST Friday for East Slopes
     Northern Cascades-Lower Garfield and Asotin Counties-Moses
     Lake Area-Northeast Mountains-Okanogan Highlands-Spokane
     Area-Upper Columbia Basin-Washington Palouse-Waterville
     Plateau-Wenatchee Area.

     Winter Storm Watch from Friday afternoon through Saturday
     afternoon for Northeast Mountains-Okanogan Highlands.

     Winter Storm Watch from Friday morning through late Friday night
     for East Slopes Northern Cascades.

&&

$$




000
FXUS66 KOTX 201320
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
520 AM PST THU NOV 20 2014

.SYNOPSIS...
A weak weather system will arrive late tonight into Thursday with
the potential for a light wintry mix of rain...snow...and freezing
rain. A stronger, wetter and windier weather system will arrive
Friday persisting into the weekend with heavy snow amounts
possible over the mountains. The weather pattern will remain
active through the middle of next week.



&&

.DISCUSSION...

...Pockets of freezing rain possible this morning over the lower
Columbia Basin and portions of the Washington Palouse...

Today and tonight ...The ridge of the past week and a half is
becoming a relic of the past as disturbance number one (of many)
is currently passing through western Washington with its sights
set on the Inland Northwest. This disturbance is comprised of an
elongating band of moisture extending from a weak upper level low
just west of Vancouver Island southeast into in southwest Idaho.
Associated with this band of moisture was a weakening warm front
which will provide the focus for the weather today. Models have
remained rather consistent in taking this front from its current
position over south-central Washington northeast across the
remainder of eastern Washington and north Idaho today. The trend
of slowing the front continues...and now it looks like the front
won`t arrive into the northern tip of Idaho until around midday.

Forcing and lifting along the front looks rather weak...and it will
likely continue to diminish as it treks northeastward today.
Nonetheless...with a modified arctic air mass still firmly
entrenched over most of the region...it won`t take much lifting to
generate precipitation as the isentropic surfaces look rather
steep. That suggests most of the region will be subject to
precipitation today...but the question is what will it fall as.
This remains an exceedingly tricky forecast element. Model cross-
sections and 0-4km max wet-bulb temperatures continue to show an
elevated wedge of above freezing air over the extreme southern
portion of our forecast area. This encompasses the area generally
south of a line from Wenatchee to Moses Lake...then Pullman. Any
locations south of this line will be subject to light freezing
rain (with a small chance of sleet)...through this morning.
Meanwhile anything north will generally see snow. Again amounts
will be fairly light. Through the end of the day most locations
will see an tenth of an inch of precipitation or less. Snow
amounts will reflect this light precipitation with locations
generally seeing less than an inch. As for the freezing
rain...amounts will also be light...however any freezing rain can
result in potential travel difficulties. The potential for travel
problems will generally be confined to the morning hours as any
diurnal heating should bring road temperatures above freezing by
midday. Additionally...most of the precipitation threat also move
north and east of this elevated warm layer as well.

The front is expected to dissipate rapidly during the
evening...but that won`t be the end of the precipitation.
Initially upslope flow and residual frontal moisture will keep the
light snow falling over north Idaho...however things will
intensify somewhat overnight. This next round of precipitation
will be delivered care of the shortwave trough off of Vancouver
Island tracking through southern British Columbia overnight. The
lifting associated with this feature will not be strong...however
the atmosphere below 650 mbs or roughly 10k feet will become
saturated overnight. Renewed isentropic ascent...especially for
locations north of Highway 2 (in Washington) and I-90 (in
Idaho)...should result in a second round of precipitation. The
warm layer will surge a little farther north as well. By
morning...a shallow elevated melting layer could move as far north
as a Lake Chelan to Spokane line. This will be on the southern
edge of the next round of precipitation so there`s a small chance
of more freezing rain...however by that time...surface wet-bulb
temperatures are expected to near or exceed freezing...so main
precipitation would be rain or a rain snow mix for the Spokane
area and southeast sections of the Columbia Basin. For locations
over the northwest portion of the Basin...including Grand
Coulee...Wilbur...and Davenport there will be a small chance of
freezing rain. Confidence is not high however...as so much is
dependent on what happens today in terms of surface warming. If a
location gets above freezing today...it will likely remain that
way overnight as well. fx


...MODERATE TO HEAVY MOUNTAIN SNOW POSSIBLE LATE FRIDAY INTO
SATURDAY...

Friday through Monday: A series of systems slide across the
Inland NW, with several opportunities for rain and snow. First
early Friday the next system will be approaching. There will be a
threat of light snow or freezing rain/freezing drizzle across the
Upper Columbia Basin through northeast WA and north ID due to some
isentropic lift and low level moisture. The moisture is deepest
below about 650 to 700 mbs, below the core of the snow growth
zone. So this suggest the potential for a mixture of snow,
freezing rain or freezing drizzle, and rain as the precipitation
type. So we could be looking for some slick conditions along the
I-90/US-2/US-95 corridor in the morning.

Then Friday afternoon into Friday evening deepening isentropic
ascent and moisture noses across the Cascades into eastern WA and
north ID with the warm front. This will lead to increasing
precipitation from west to east, so that by early evening most of
Washington will be enveloped by it and by middle to late evening
much of Idaho will be too. Overnight the associated cold front
slips east of the Cascades, leading to dwindling precipitation in
the lee of the Cascades and western Columbia Basin. By late
Saturday morning to afternoon the highest threat briefly retreats
to the mountains, with winds becoming breezy to locally windy.
With the evolution discussed, the next questions surround snow
levels and precipitation amounts.

* Snow levels: The location of the snow hasn`t changed much from
  previous thinking. Based on wet-bulb zero heights, snow levels
  from Friday afternoon through Friday night will be around
  3000-4000 feet across the Cascades and northern mountains and
  4000 to 5000 feet southeast. However colder air trapped near the
  Cascades in the low level southeast flow will keep snow levels
  1500-3000 feet. This includes places in the lee of the Cascades,
  including the Okanogan Valley and Highlands through the
  Waterville Plateau and Wenatchee area. So the Cascades and areas
  the remaining mountain areas above 3000 to 4000 feet (except for
  the Blue Mountains where snow levels look too high to have much
  impact in the populated areas). Winter storm watches
  remain place for the Cascades and in the north WA and ID
  mountains above 4000 feet. We will monitor the potential need
  for advisories outside of the mountains, in the hills around the
  Okanogan Valley and Waterville Plateau and Wenatchee area.
  However accumulations may be limited if milder air is able to
  move in or precipitation amounts are not as high as expected.
  Behind the cold front going into Saturday afternoon snow levels
  drop to between 2500-3000 feet. So this means any lingering
  showers may be a mix of rain and snow, including as far south as
  the I-90 corridor. However by then the better precipitation
  threat starts that shift into the mountains.

* Precipitation amounts: Regional PWATs rise to between 0.45 to
  0.75 inches (or 130 to 200% of normal). So this is a juicy
  system and all models generate decent precipitation amounts. In
  the 24-hour period between Friday afternoon and Saturday
  afternoon models generate between 0.30 to 0.60 inches of liquid
  precipitation across a good portion of the Inland NW, with lower
  amounts over the deeper Columbia Basin and higher amounts
  between 0.75 to 1.0 inch in the mountains. For areas the
  mountain snow this could translate to between 6 to 12 inches,
  while the lower elevations closer to the Cascades could see
  anywhere from a trace to a couple inches or so. These numbers,
  especially the lower elevation ones, will continue to be fine-
  tuned.

From Saturday evening into Sunday morning a secondary disturbance
slips by, renewing the precipitation threat outside of the
mountains. However precipitation amount as compared to Friday
night, look light. A third and more organized system comes in
sometime between Sunday and Monday morning. This taps some
subtropical moisture, but it is not as robust as the Friday night
system. Still models generate a modest precipitation threat across
all but the lee of the Cascades and deeper Basin. When and where
this develops is where model disagreement lingers. Most models
start precipitation early Sunday near Cascades. Yet farther east
some start it up through southeast WA and the central Panhandle in
the morning and others hold it off until afternoon. Chances remain
high outside of the lee of the Cascades and deeper Columbia Basin
through the evening, then dissipate overnight into Monday. Still
the leading edge of a fourth system, a warm front, approaches from
the west Monday afternoon. Whether moisture is deep enough to
allow precipitation to redevelop or just thickening clouds is even
less agreed upon. Chances will remain high near the Cascades and
lower elsewhere. As for snow levels through the period from
Saturday night through Monday, they waver between about 1500 and
3000 feet during the night and early morning hours and 2000 and
4000 feet during the day and early evening hours. The lowest of
those lay toward the northeast WA and north ID. This translates to
the potential for snow down to valley floors, especially at night,
and perhaps some light accumulations in the valleys. This includes
potentially the I-90 corridor, especially east of Ritzville and
the higher Palouse, as well as areas from the Waterville Plateau
north. /J. Cote`

Monday Night through Thursday: Pattern looks to remain active
early in the week as the moist northwesterly flow continues to
influence our weather. Exactly how long we remain active is up for
debate amongst the models at this point. The GFS brings an
offshore ridge near the west coast shifting the majority of the
atmospheric dynamics and moisture to the north ultimately leading
to a drier forecast. The ECMWF with support from the Canadian
model keeps the ridge further offshore and the opportunity for
precipitation alive much later into the week. At this point I have
leaned toward the Euro due to performance up to this point with
winter systems and kept POPs above climo through Wednesday. Along
with precip into the middle of the week, the Euro also brings
another round of cold continental polar air into the region
starting Wednesday sending our temperatures back below normal. In
turn the temperatures were trended down, but not yet to the full
extent of the ECMWF as I want just a bit more confidence. The
polar airmass is also quite dry so once the modified polar front
passes Wednesday, POPs drop off as well. Snow levels with the
precipitation in the extended forecast once again looks to sit
above most valley floors minus the far northern ones leading to
mainly a valley rain/mountain snow event. Higher benches such as
the West Plains, Upper Columbia Basin, etc. could see some snow
mix in overnight as our diurnal swings bottoms out. While this
forecast leaned more towards the Euro, model trends will have to
be closely monitored to better pin down the details as we near
this timeframe. /Fliehman

&&

.AVIATION...
12Z TAFS: A weak frontal boundary will continue to lift to the
northeast this morning potentially impacting all forecast sites.
The threat will exit MWH and EAT by 15z and the other sites
between 17-19z. While vsbys and cigs will generally be in the VFR
category...brief MVFR conditions will be possible but not worth
mentioning in forecast. The most difficult part of the forecast is
what will the precipitation fall as. Based on elevated melting
layer and temperatures near or below freezing at all sites...a
winter mix is expected with the best chances of freezing rain
expected for PUW and MWH. Confidence is low though as this is a
very complex situation. The front will exit the area...with dry
weather for most sites afterwords. Later tonight another round of
precipitation arrives late tonight (after 08z) and this will
mainly impact GEG- SFF- COE. Suspect this round will mainly be
rain...but that is far from certain. fx

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        34  31  38  34  42  29 /  50  30  40 100  60  30
Coeur d`Alene  34  32  40  33  41  31 /  70  40  50 100  70  30
Pullman        39  29  42  35  42  32 /  60  10  20 100  70  30
Lewiston       40  31  45  39  47  35 /  80  10  10  80  50  30
Colville       34  26  38  34  43  26 /  50  40  70 100  40  30
Sandpoint      34  30  39  33  41  29 /  60  70  70 100  70  30
Kellogg        34  31  39  32  39  32 /  90  60  60 100  90  40
Moses Lake     35  21  37  31  47  28 /  60   0  70 100  30  20
Wenatchee      39  28  36  31  45  31 /  70   0  80 100  20  30
Omak           36  27  37  30  43  27 /  50  20  90 100  20  30

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Air Stagnation Advisory until Noon PST Friday for Central
     Panhandle Mountains-Coeur d`Alene Area-Idaho Palouse-
     Northern Panhandle.

     Winter Storm Watch from Friday afternoon through Saturday
     afternoon for Central Panhandle Mountains-Northern
     Panhandle.

WA...Air Stagnation Advisory until Noon PST Friday for East Slopes
     Northern Cascades-Lower Garfield and Asotin Counties-Moses
     Lake Area-Northeast Mountains-Okanogan Highlands-Spokane
     Area-Upper Columbia Basin-Washington Palouse-Waterville
     Plateau-Wenatchee Area.

     Winter Storm Watch from Friday afternoon through Saturday
     afternoon for Northeast Mountains-Okanogan Highlands.

     Winter Storm Watch from Friday morning through late Friday night
     for East Slopes Northern Cascades.

&&

$$





000
FXUS66 KSEW 201144
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
344 AM PST THU NOV 20 2014

.SYNOPSIS...WEAK LOW PRESSURE ALOFT WILL PREVAIL OVER THE REGION
TODAY FOR SCATTERED SHOWERS. THE AREA WILL BE BETWEEN SYSTEMS
TONIGHT. A STRONGER PACIFIC STORM WILL IMPACT THE REGION ON FRIDAY
FOR LOCALLY HEAVY RAIN AND GUSTY WINDS...ALONG WITH THE POTENTIAL
FOR DECENT SNOWFALL IN THE MOUNTAINS. THE WEATHER PATTERN WILL
REMAIN WET AND UNSETTLED THIS WEEKEND.

&&

.SHORT TERM...
A WEAK COLD OR OCCLUDED FRONT WAS MOVING ACROSS THE CWA AT THIS
TIME AND WILL EXIT THE AREA BY SUNRISE. IT LOOKS LIKE THE THREAT
OF FREEZING RAIN HAS ENDED IN THE PASSES. THE PRECIP WILL MOST
LIKELY FALL AS SNOW OR A RAIN/SNOW MIX...DEPENDING ON THE
ELEVATION. NOT MUCH PRECIP WAS OCCURRING BEHIND THE FRONT PER
DOPPLER RADAR DATA. THUS...LOOK FOR SCATTERED SHOWERS TO PREVAIL
ACROSS THE AREA TODAY UNDER WEAK CYCLONIC FLOW ALOFT.

WESTERN WA WILL BE BETWEEN SYSTEMS TONIGHT BUT THERE MAY BE A FEW
LINGERING SHOWERS OVER THE AREA...ESPECIALLY OVER THE NORTH COAST
AND NORTH CASCADES.

A STRONGER PACIFIC STORM WILL IMPACT THE REGION ON FRI FOR LOCALLY
HEAVY RAIN AND GUSTY WINDS IN THE FAVORED AREAS /COAST AND
NORTH INTERIOR/. A WIND ADVISORY WILL LIKELY BE NEEDED FOR THESE
AREAS FOR LATE FRI MORNING THROUGH AT LEAST FRI AFTERNOON.

IT LOOKS LIKE THE CASCADES ABOVE 4000 FEET WILL RECEIVE WINTER
WEATHER ADVISORY CRITERIA SNOWFALL AMOUNTS OR AMOUNTS IN THE 6 TO
11 INCH RANGE FRI NIGHT...ALTHOUGH IT IS POSSIBLE THAT MOUNT BAKER
COULD RECEIVE ABOUT A FOOT OF SNOW.

THE COLD FRONT WILL SWEEP ACROSS THE CWA FRI NIGHT. EXPECT THE
UPPER TROF TO MOVE ACROSS THE REGION EARLY SATURDAY. THE AIR MASS
WILL REMAIN UNSTABLE ENOUGH FOR PLENTY OF SHOWERS ON SATURDAY. IN
ADDITION...A PUGET SOUND CONVERGENCE ZONE WILL LIKELY DEVELOP IN
ITS FAVORED LOCATION...NEAR THE KING/SNOHOMISH COUNTY BORDER...IN
THE WAKE OF THE COLD FRONT.

.LONG TERM...
ANOTHER LOW PRESSURE SYSTEM WILL MOVE ACROSS THE PACIFIC NORTHWEST
ON SUNDAY...THUS POPS WERE BUMPED UP TO CATEGORICAL. AN UPPER
RIDGE IS EXPECTED TO PREVAIL OVER THE REGION ON MON. IF THIS TREND
CONTINUES...LATER SHIFTS COULD REMOVE POPS FROM THE FORECAST
ALTOGETHER. BEYOND MON...THE MEDIUM RANGE SOLUTIONS DIVERGED...
THEREFORE CONFIDENCE IN THE FORECAST FOR TUE AND WED WERE NOT
HIGH. LEFT THE INHERITED FORECAST INTACT FOR THIS REASON.

&&

.HYDROLOGY...
RIVER FLOODING IS NOT EXPECTED THE NEXT 7 DAYS.

&&

.AVIATION...A COLD FRONT NOW OVER WESTERN WASHINGTON WILL EXIT TO
THE NORTHEAST THIS MORNING. SOUTHERLY FLOW ALOFT WILL BECOME
WESTERLY. AT THE SURFACE MODERATE SOUTHEAST GRADIENTS WILL EASE IN
THE AFTERNOON. AFTER THE FRONT PASSES THE AIR MASS WILL BE MOIST AND
SLIGHTLY UNSTABLE WITH SCATTERED SHOWERS.

CEILINGS BEHIND THE FRONT WILL GENERALLY BE 2-4K FT WITH A FEW IFR
CEILINGS AT TIMES. SOME IMPROVEMENT IN THE AFTERNOON AND EVENING IS
LIKELY.

KSEA...MVFR CEILINGS LIKELY THIS MORNING WITH SOME IMPROVEMENT IN
THE AFTERNOON. WIND SOUTHEAST 6-10 KT. CHB

&&

.MARINE...MODERATE SOUTHEAST FLOW IN THE WAKE OF A FRONT WILL KEEP
SMALL CRAFT ADVISORY WINDS GOING OVER MOST WATERS THIS MORNING.
WINDS WILL EASE IN THE AFTERNOON.

MODELS BRING A STRONGER FRONT INLAND FRIDAY. SOLID GALES ARE LIKELY
OVER THE COAST FRIDAY AFTERNOON AND EVENING AND THE WARNING IS NOW
POSTED. MODELS SHOW SOME GALE FORCE WINDS OVER THE EAST ENTRANCE AND
NORTHERN INLAND WATERS AND THERE IS NOW A GALE WATCH FOR THOSE AREAS.

WESTERLY FLOW ALOFT OVER THE NORTHEAST PACIFIC SATURDAY THROUGH
MONDAY WILL BRING SEVERAL WEAK SYSTEMS ACROSS THE AREA. POST FRONTAL
WINDS ON SATURDAY COULD HAVE SOME PUNCH BUT FOR NOW HAVE KEPT WINDS
UNDER GALE FORCE. SWELLS IN THE 15-20 FOOT RANGE ARE FORECAST TO
REACH THE COAST SUNDAY. CHB

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY IN EFFECT TIL 10 AM THIS MORNING FOR ALL
     WATERS EXCEPT THE CENTRAL STRAIT OF JUAN DE FUCA AND THE
     PUGET SOUND/HOOD CANAL.

     SMALL CRAFT ADVISORY IN EFFECT FOR ROUGH BAR TIL 6 AM FRIDAY
     FOR THE GRAYS HARBOR BAR.

     GALE WARNING IN EFFECT FROM 7 AM TO 10 PM FRIDAY FOR THE
     COASTAL WATERS.

     GALE WATCH IN EFFECT FROM FRIDAY MORNING THROUGH FRIDAY
     EVENING FOR EAST ENTRANCE TO THE STRAIT OF JUAN DE FUCA AND
     THE NORTHERN INLAND WATERS.

&&

$$

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WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML





000
FXUS66 KSEW 201144
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
344 AM PST THU NOV 20 2014

.SYNOPSIS...WEAK LOW PRESSURE ALOFT WILL PREVAIL OVER THE REGION
TODAY FOR SCATTERED SHOWERS. THE AREA WILL BE BETWEEN SYSTEMS
TONIGHT. A STRONGER PACIFIC STORM WILL IMPACT THE REGION ON FRIDAY
FOR LOCALLY HEAVY RAIN AND GUSTY WINDS...ALONG WITH THE POTENTIAL
FOR DECENT SNOWFALL IN THE MOUNTAINS. THE WEATHER PATTERN WILL
REMAIN WET AND UNSETTLED THIS WEEKEND.

&&

.SHORT TERM...
A WEAK COLD OR OCCLUDED FRONT WAS MOVING ACROSS THE CWA AT THIS
TIME AND WILL EXIT THE AREA BY SUNRISE. IT LOOKS LIKE THE THREAT
OF FREEZING RAIN HAS ENDED IN THE PASSES. THE PRECIP WILL MOST
LIKELY FALL AS SNOW OR A RAIN/SNOW MIX...DEPENDING ON THE
ELEVATION. NOT MUCH PRECIP WAS OCCURRING BEHIND THE FRONT PER
DOPPLER RADAR DATA. THUS...LOOK FOR SCATTERED SHOWERS TO PREVAIL
ACROSS THE AREA TODAY UNDER WEAK CYCLONIC FLOW ALOFT.

WESTERN WA WILL BE BETWEEN SYSTEMS TONIGHT BUT THERE MAY BE A FEW
LINGERING SHOWERS OVER THE AREA...ESPECIALLY OVER THE NORTH COAST
AND NORTH CASCADES.

A STRONGER PACIFIC STORM WILL IMPACT THE REGION ON FRI FOR LOCALLY
HEAVY RAIN AND GUSTY WINDS IN THE FAVORED AREAS /COAST AND
NORTH INTERIOR/. A WIND ADVISORY WILL LIKELY BE NEEDED FOR THESE
AREAS FOR LATE FRI MORNING THROUGH AT LEAST FRI AFTERNOON.

IT LOOKS LIKE THE CASCADES ABOVE 4000 FEET WILL RECEIVE WINTER
WEATHER ADVISORY CRITERIA SNOWFALL AMOUNTS OR AMOUNTS IN THE 6 TO
11 INCH RANGE FRI NIGHT...ALTHOUGH IT IS POSSIBLE THAT MOUNT BAKER
COULD RECEIVE ABOUT A FOOT OF SNOW.

THE COLD FRONT WILL SWEEP ACROSS THE CWA FRI NIGHT. EXPECT THE
UPPER TROF TO MOVE ACROSS THE REGION EARLY SATURDAY. THE AIR MASS
WILL REMAIN UNSTABLE ENOUGH FOR PLENTY OF SHOWERS ON SATURDAY. IN
ADDITION...A PUGET SOUND CONVERGENCE ZONE WILL LIKELY DEVELOP IN
ITS FAVORED LOCATION...NEAR THE KING/SNOHOMISH COUNTY BORDER...IN
THE WAKE OF THE COLD FRONT.

.LONG TERM...
ANOTHER LOW PRESSURE SYSTEM WILL MOVE ACROSS THE PACIFIC NORTHWEST
ON SUNDAY...THUS POPS WERE BUMPED UP TO CATEGORICAL. AN UPPER
RIDGE IS EXPECTED TO PREVAIL OVER THE REGION ON MON. IF THIS TREND
CONTINUES...LATER SHIFTS COULD REMOVE POPS FROM THE FORECAST
ALTOGETHER. BEYOND MON...THE MEDIUM RANGE SOLUTIONS DIVERGED...
THEREFORE CONFIDENCE IN THE FORECAST FOR TUE AND WED WERE NOT
HIGH. LEFT THE INHERITED FORECAST INTACT FOR THIS REASON.

&&

.HYDROLOGY...
RIVER FLOODING IS NOT EXPECTED THE NEXT 7 DAYS.

&&

.AVIATION...A COLD FRONT NOW OVER WESTERN WASHINGTON WILL EXIT TO
THE NORTHEAST THIS MORNING. SOUTHERLY FLOW ALOFT WILL BECOME
WESTERLY. AT THE SURFACE MODERATE SOUTHEAST GRADIENTS WILL EASE IN
THE AFTERNOON. AFTER THE FRONT PASSES THE AIR MASS WILL BE MOIST AND
SLIGHTLY UNSTABLE WITH SCATTERED SHOWERS.

CEILINGS BEHIND THE FRONT WILL GENERALLY BE 2-4K FT WITH A FEW IFR
CEILINGS AT TIMES. SOME IMPROVEMENT IN THE AFTERNOON AND EVENING IS
LIKELY.

KSEA...MVFR CEILINGS LIKELY THIS MORNING WITH SOME IMPROVEMENT IN
THE AFTERNOON. WIND SOUTHEAST 6-10 KT. CHB

&&

.MARINE...MODERATE SOUTHEAST FLOW IN THE WAKE OF A FRONT WILL KEEP
SMALL CRAFT ADVISORY WINDS GOING OVER MOST WATERS THIS MORNING.
WINDS WILL EASE IN THE AFTERNOON.

MODELS BRING A STRONGER FRONT INLAND FRIDAY. SOLID GALES ARE LIKELY
OVER THE COAST FRIDAY AFTERNOON AND EVENING AND THE WARNING IS NOW
POSTED. MODELS SHOW SOME GALE FORCE WINDS OVER THE EAST ENTRANCE AND
NORTHERN INLAND WATERS AND THERE IS NOW A GALE WATCH FOR THOSE AREAS.

WESTERLY FLOW ALOFT OVER THE NORTHEAST PACIFIC SATURDAY THROUGH
MONDAY WILL BRING SEVERAL WEAK SYSTEMS ACROSS THE AREA. POST FRONTAL
WINDS ON SATURDAY COULD HAVE SOME PUNCH BUT FOR NOW HAVE KEPT WINDS
UNDER GALE FORCE. SWELLS IN THE 15-20 FOOT RANGE ARE FORECAST TO
REACH THE COAST SUNDAY. CHB

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY IN EFFECT TIL 10 AM THIS MORNING FOR ALL
     WATERS EXCEPT THE CENTRAL STRAIT OF JUAN DE FUCA AND THE
     PUGET SOUND/HOOD CANAL.

     SMALL CRAFT ADVISORY IN EFFECT FOR ROUGH BAR TIL 6 AM FRIDAY
     FOR THE GRAYS HARBOR BAR.

     GALE WARNING IN EFFECT FROM 7 AM TO 10 PM FRIDAY FOR THE
     COASTAL WATERS.

     GALE WATCH IN EFFECT FROM FRIDAY MORNING THROUGH FRIDAY
     EVENING FOR EAST ENTRANCE TO THE STRAIT OF JUAN DE FUCA AND
     THE NORTHERN INLAND WATERS.

&&

$$

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000
FXUS66 KOTX 201120
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
320 AM PST THU NOV 20 2014

.SYNOPSIS...
A weak weather system will arrive late tonight into Thursday with
the potential for a light wintry mix of rain...snow...and freezing
rain. A stronger, wetter and windier weather system will arrive
Friday persisting into the weekend with heavy snow amounts
possible over the mountains. The weather pattern will remain
active through the middle of next week.



&&

.DISCUSSION...

...Pockets of freezing rain possible this morning over the lower
Columbia Basin and portions of the Washington Palouse...

Today and tonight ...The ridge of the past week and a half is
becoming a relic of the past as disturbance number one (of many)
is currently passing through western Washington with its sights
set on the Inland Northwest. This disturbance is comprised of an
elongating band of moisture extending from a weak upper level low
just west of Vancouver Island southeast into in southwest Idaho.
Associated with this band of moisture was a weakening warm front
which will provide the focus for the weather today. Models have
remained rather consistent in taking this front from its current
position over south-central Washington northeast across the
remainder of eastern Washington and north Idaho today. The trend
of slowing the front continues...and now it looks like the front
won`t arrive into the northern tip of Idaho until around midday.

Forcing and lifting along the front looks rather weak...and it will
likely continue to diminish as it treks northeastward today.
Nonetheless...with a modified arctic air mass still firmly
entrenched over most of the region...it won`t take much lifting to
generate precipitation as the isentropic surfaces look rather
steep. That suggests most of the region will be subject to
precipitation today...but the question is what will it fall as.
This remains an exceedingly tricky forecast element. Model cross-
sections and 0-4km max wet-bulb temperatures continue to show an
elevated wedge of above freezing air over the extreme southern
portion of our forecast area. This encompasses the area generally
south of a line from Wenatchee to Moses Lake...then Pullman. Any
locations south of this line will be subject to light freezing
rain (with a small chance of sleet)...through this morning.
Meanwhile anything north will generally see snow. Again amounts
will be fairly light. Through the end of the day most locations
will see an tenth of an inch of precipitation or less. Snow
amounts will reflect this light precipitation with locations
generally seeing less than an inch. As for the freezing
rain...amounts will also be light...however any freezing rain can
result in potential travel difficulties. The potential for travel
problems will generally be confined to the morning hours as any
dirunal heating should bring road temperatures above freezing by
midday. Additionally...most of the precipitation threat also move
north and east of this elevated warm layer as well.

The front is expected to dissipate rapidly during the
evening...but that won`t be the end of the precipitation.
Initially upslope flow and residual frontal moisture will keep the
light snow falling over north Idaho...however things will
intensify somewhat overnight. This next round of precipitation
will be delivered care of the shortwave trough off of Vancouver
Island tracking through southern British Columbia overnight. The
lifting associated with this feature will not be strong...however
the atmosphere below 650 mbs or roughly 10k feet will become
saturated overnight. Renewed isentropic ascent...especially for
locations north of Highway 2 (in Washington) and I-90 (in
Idaho)...should result in a second round of precipitation. The
warm layer will surge a little farther north as well. By
morning...a shallow elevated melting layer could move as far north
as a Lake Chelan to Spokane line. This will be on the southern
edge of the next round of precipitation so there`s a small chance
of more freezing rain...however by that time...surface wet-bulb
temperatures are expected to near or exceed freezing...so main
precipitation would be rain or a rain snow mix for the Spokane
area and southeast sections of the Columbia Basin. For locations
over the northwest portion of the Basin...including Grand
Coulee...Wilbur...and Davenport there will be a small chance of
freezing rain. Confidence is not high however...as so much is
dependant on what happens today in terms of surface warming. If a
location gets above freezing today...it will likely remain that
way overnight as well. fx


...MODERATE TO HEAVY MOUNTAIN SNOW POSSIBLE LATE FRIDAY INTO
SATURDAY...

Friday through Monday: A series of systems slide across the
Inland NW, with several opportunities for rain and snow. First
early Friday the next system will be approaching. There will be a
threat of light snow or freezing rain/freezing drizzle across the
Upper Columbia Basin through northeast WA and north ID due to some
isentropic lift and low level moisture. The moisture is deepest
below about 650 to 700 mbs, below the core of the snow growth
zone. So this suggest the potential for a mixture of snow,
freezing rain or freezing drizzle, and rain as the precipitation
type. So we could be looking for some slick conditions along the
I-90/US-2/US-95 corridor in the morning.

Then Friday afternoon into Friday evening deepening isentropic
ascent and moisture noses across the Cascades into eastern WA and
north ID with the warm front. This will lead to increasing
precipitation from west to east, so that by early evening most of
Washington will be enveloped by it and by middle to late evening
much of Idaho will be too. Overnight the associated cold front
slips east of the Cascades, leading to dwindling precipitation in
the lee of the Cascades and western Columbia Basin. By late
Saturday morning to afternoon the highest threat briefly retreats
to the mountains, with winds becoming breezy to locally windy.
With the evolution discussed, the next questions surround snow
levels and precipitation amounts.

* Snow levels: The location of the snow hasn`t changed much from
  previous thinking. Based on wet-bulb zero heights, snow levels
  from Friday afternoon through Friday night will be around
  3000-4000 feet across the Cascades and northern mountains and
  4000 to 5000 feet southeast. However colder air trapped near the
  Cascades in the low level southeast flow will keep snow levels
  1500-3000 feet. This includes places in the lee of the Cascades,
  including the Okanogan Valley and Highlands through the
  Waterville Plateau and Wenatchee area. So the Cascades and areas
  the remaining mountain areas above 3000 to 4000 feet (except for
  the Blue Mountains where snow levels look too high to have much
  impact in the populated areas). Winter storm watches
  remain place for the Cascades and in the north WA and ID
  mountains above 4000 feet. We will monitor the potential need
  for advisories outside of the mountains, in the hills around the
  Okanogan Valley and Waterville Plateau and Wenatchee area.
  However accumulations may be limited if milder air is able to
  move in or precipitation amounts are not as high as expected.
  Behind the cold front going into Saturday afternoon snow levels
  drop to between 2500-3000 feet. So this means any lingering
  showers may be a mix of rain and snow, including as far south as
  the I-90 corridor. However by then the better precipitation
  threat starts that shift into the mountains.

* Precipitation amounts: Regional PWATs rise to between 0.45 to
  0.75 inches (or 130 to 200% of normal). So this is a juicy
  system and all models generate decent precipitation amounts. In
  the 24-hour period between Friday afternoon and Saturday
  afternoon models generate between 0.30 to 0.60 inches of liquid
  precipitation across a good portion of the Inland NW, with lower
  amounts over the deeper Columbia Basin and higher amounts
  between 0.75 to 1.0 inch in the mountains. For areas the
  mountain snow this could translate to between 6 to 12 inches,
  while the lower elevations closer to the Cascades could see
  anywhere from a trace to a couple inches or so. These numbers,
  especially the lower elevation ones, will continue to be fine-
  tuned.

From Saturday evening into Sunday morning a secondary disturbance
slips by, renewing the precipitation threat outside of the
mountains. However precipitation amount as compared to Friday
night, look light. A third and more organized system comes in
sometime between Sunday and Monday morning. This taps some
subtropical moisture, but it is not as robust as the Friday night
system. Still models generate a modest precipitation threat across
all but the lee of the Cascades and deeper Basin. When and where
this develops is where model disagreement lingers. Most models
start precipitation early Sunday near Cascades. Yet farther east
some start it up through southeast WA and the central Panhandle in
the morning and others hold it off until afternoon. Chances remain
high outside of the lee of the Cascades and deeper Columbia Basin
through the evening, then dissipate overnight into Monday. Still
the leading edge of a fourth system, a warm front, approaches from
the west Monday afternoon. Whether moisture is deep enough to
allow precipitation to redevelop or just thickening clouds is even
less agreed upon. Chances will remain high near the Cascades and
lower elsewhere. As for snow levels through the period from
Saturday night through Monday, they waver between about 1500 and
3000 feet during the night and early morning hours and 2000 and
4000 feet during the day and early evening hours. The lowest of
those lay toward the northeast WA and north ID. This translates to
the potential for snow down to valley floors, especially at night,
and perhaps some light accumulations in the valleys. This includes
potentially the I-90 corridor, especially east of Ritzville and
the higher Palouse, as well as areas from the Waterville Plateau
north. /J. Cote`

Monday Night through Thursday: Pattern looks to remain active
early in the week as the moist northwesterly flow continues to
influence our weather. Exactly how long we remain active is up for
debate amongst the models at this point. The GFS brings an
offshore ridge near the west coast shifting the majority of the
atmospheric dynamics and moisture to the north ultimately leading
to a drier forecast. The ECMWF with support from the Canadian
model keeps the ridge further offshore and the opportunity for
precipitation alive much later into the week. At this point I have
leaned toward the Euro due to performance up to this point with
winter systems and kept POPs above climo through Wednesday. Along
with precip into the middle of the week, the Euro also brings
another round of cold continental polar air into the region
starting Wednesday sending our temperatures back below normal. In
turn the temperatures were trended down, but not yet to the full
extent of the ECMWF as I want just a bit more confidence. The
polar airmass is also quite dry so once the modified polar front
passes Wednesday, POPs drop off as well. Snow levels with the
precipitation in the extended forecast once again looks to sit
above most valley floors minus the far northern ones leading to
mainly a valley rain/mountain snow event. Higher benches such as
the West Plains, Upper Columbia Basin, etc. could see some snow
mix in overnight as our diurnal swings bottoms out. While this
forecast leaned more towards the Euro, model trends will have to
be closely monitored to better pin down the details as we near
this timeframe. /Fliehman

&&

.AVIATION...
06Z TAFS: A weak frontal boundary lifts into the region between
09-13Z spreading a wintry mix of light snow, sleet, and some
freezing rain. Accumulations, if any, are expected to be very
light. After the front moves off Thursday morning...a moist
boundary layer with weak upslope flow will maintain the threat of
MVFR ceilings over the eastern TAF sites. /sb

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        34  31  38  34  42  29 /  50  30  40 100  60  30
Coeur d`Alene  34  32  40  33  41  31 /  70  40  50 100  70  30
Pullman        39  29  42  35  42  32 /  60  10  20 100  70  30
Lewiston       40  31  45  39  47  35 /  80  10  10  80  50  30
Colville       34  26  38  34  43  26 /  50  40  70 100  40  30
Sandpoint      34  30  39  33  41  29 /  60  70  70 100  70  30
Kellogg        34  31  39  32  39  32 /  90  60  60 100  90  40
Moses Lake     35  21  37  31  47  28 /  60   0  70 100  30  20
Wenatchee      39  28  36  31  45  31 /  70   0  80 100  20  30
Omak           36  27  37  30  43  27 /  50  20  90 100  20  30

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Air Stagnation Advisory until Noon PST Friday for Central
     Panhandle Mountains-Coeur d`Alene Area-Idaho Palouse-
     Northern Panhandle.

     Winter Storm Watch from Friday afternoon through Saturday
     afternoon for Central Panhandle Mountains-Northern
     Panhandle.

WA...Air Stagnation Advisory until Noon PST Friday for East Slopes
     Northern Cascades-Lower Garfield and Asotin Counties-Moses
     Lake Area-Northeast Mountains-Okanogan Highlands-Spokane
     Area-Upper Columbia Basin-Washington Palouse-Waterville
     Plateau-Wenatchee Area.

     Winter Storm Watch from Friday afternoon through Saturday
     afternoon for Northeast Mountains-Okanogan Highlands.

     Winter Storm Watch from Friday morning through late Friday night
     for East Slopes Northern Cascades.

&&

$$





000
FXUS66 KOTX 201120
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
320 AM PST THU NOV 20 2014

.SYNOPSIS...
A weak weather system will arrive late tonight into Thursday with
the potential for a light wintry mix of rain...snow...and freezing
rain. A stronger, wetter and windier weather system will arrive
Friday persisting into the weekend with heavy snow amounts
possible over the mountains. The weather pattern will remain
active through the middle of next week.



&&

.DISCUSSION...

...Pockets of freezing rain possible this morning over the lower
Columbia Basin and portions of the Washington Palouse...

Today and tonight ...The ridge of the past week and a half is
becoming a relic of the past as disturbance number one (of many)
is currently passing through western Washington with its sights
set on the Inland Northwest. This disturbance is comprised of an
elongating band of moisture extending from a weak upper level low
just west of Vancouver Island southeast into in southwest Idaho.
Associated with this band of moisture was a weakening warm front
which will provide the focus for the weather today. Models have
remained rather consistent in taking this front from its current
position over south-central Washington northeast across the
remainder of eastern Washington and north Idaho today. The trend
of slowing the front continues...and now it looks like the front
won`t arrive into the northern tip of Idaho until around midday.

Forcing and lifting along the front looks rather weak...and it will
likely continue to diminish as it treks northeastward today.
Nonetheless...with a modified arctic air mass still firmly
entrenched over most of the region...it won`t take much lifting to
generate precipitation as the isentropic surfaces look rather
steep. That suggests most of the region will be subject to
precipitation today...but the question is what will it fall as.
This remains an exceedingly tricky forecast element. Model cross-
sections and 0-4km max wet-bulb temperatures continue to show an
elevated wedge of above freezing air over the extreme southern
portion of our forecast area. This encompasses the area generally
south of a line from Wenatchee to Moses Lake...then Pullman. Any
locations south of this line will be subject to light freezing
rain (with a small chance of sleet)...through this morning.
Meanwhile anything north will generally see snow. Again amounts
will be fairly light. Through the end of the day most locations
will see an tenth of an inch of precipitation or less. Snow
amounts will reflect this light precipitation with locations
generally seeing less than an inch. As for the freezing
rain...amounts will also be light...however any freezing rain can
result in potential travel difficulties. The potential for travel
problems will generally be confined to the morning hours as any
dirunal heating should bring road temperatures above freezing by
midday. Additionally...most of the precipitation threat also move
north and east of this elevated warm layer as well.

The front is expected to dissipate rapidly during the
evening...but that won`t be the end of the precipitation.
Initially upslope flow and residual frontal moisture will keep the
light snow falling over north Idaho...however things will
intensify somewhat overnight. This next round of precipitation
will be delivered care of the shortwave trough off of Vancouver
Island tracking through southern British Columbia overnight. The
lifting associated with this feature will not be strong...however
the atmosphere below 650 mbs or roughly 10k feet will become
saturated overnight. Renewed isentropic ascent...especially for
locations north of Highway 2 (in Washington) and I-90 (in
Idaho)...should result in a second round of precipitation. The
warm layer will surge a little farther north as well. By
morning...a shallow elevated melting layer could move as far north
as a Lake Chelan to Spokane line. This will be on the southern
edge of the next round of precipitation so there`s a small chance
of more freezing rain...however by that time...surface wet-bulb
temperatures are expected to near or exceed freezing...so main
precipitation would be rain or a rain snow mix for the Spokane
area and southeast sections of the Columbia Basin. For locations
over the northwest portion of the Basin...including Grand
Coulee...Wilbur...and Davenport there will be a small chance of
freezing rain. Confidence is not high however...as so much is
dependant on what happens today in terms of surface warming. If a
location gets above freezing today...it will likely remain that
way overnight as well. fx


...MODERATE TO HEAVY MOUNTAIN SNOW POSSIBLE LATE FRIDAY INTO
SATURDAY...

Friday through Monday: A series of systems slide across the
Inland NW, with several opportunities for rain and snow. First
early Friday the next system will be approaching. There will be a
threat of light snow or freezing rain/freezing drizzle across the
Upper Columbia Basin through northeast WA and north ID due to some
isentropic lift and low level moisture. The moisture is deepest
below about 650 to 700 mbs, below the core of the snow growth
zone. So this suggest the potential for a mixture of snow,
freezing rain or freezing drizzle, and rain as the precipitation
type. So we could be looking for some slick conditions along the
I-90/US-2/US-95 corridor in the morning.

Then Friday afternoon into Friday evening deepening isentropic
ascent and moisture noses across the Cascades into eastern WA and
north ID with the warm front. This will lead to increasing
precipitation from west to east, so that by early evening most of
Washington will be enveloped by it and by middle to late evening
much of Idaho will be too. Overnight the associated cold front
slips east of the Cascades, leading to dwindling precipitation in
the lee of the Cascades and western Columbia Basin. By late
Saturday morning to afternoon the highest threat briefly retreats
to the mountains, with winds becoming breezy to locally windy.
With the evolution discussed, the next questions surround snow
levels and precipitation amounts.

* Snow levels: The location of the snow hasn`t changed much from
  previous thinking. Based on wet-bulb zero heights, snow levels
  from Friday afternoon through Friday night will be around
  3000-4000 feet across the Cascades and northern mountains and
  4000 to 5000 feet southeast. However colder air trapped near the
  Cascades in the low level southeast flow will keep snow levels
  1500-3000 feet. This includes places in the lee of the Cascades,
  including the Okanogan Valley and Highlands through the
  Waterville Plateau and Wenatchee area. So the Cascades and areas
  the remaining mountain areas above 3000 to 4000 feet (except for
  the Blue Mountains where snow levels look too high to have much
  impact in the populated areas). Winter storm watches
  remain place for the Cascades and in the north WA and ID
  mountains above 4000 feet. We will monitor the potential need
  for advisories outside of the mountains, in the hills around the
  Okanogan Valley and Waterville Plateau and Wenatchee area.
  However accumulations may be limited if milder air is able to
  move in or precipitation amounts are not as high as expected.
  Behind the cold front going into Saturday afternoon snow levels
  drop to between 2500-3000 feet. So this means any lingering
  showers may be a mix of rain and snow, including as far south as
  the I-90 corridor. However by then the better precipitation
  threat starts that shift into the mountains.

* Precipitation amounts: Regional PWATs rise to between 0.45 to
  0.75 inches (or 130 to 200% of normal). So this is a juicy
  system and all models generate decent precipitation amounts. In
  the 24-hour period between Friday afternoon and Saturday
  afternoon models generate between 0.30 to 0.60 inches of liquid
  precipitation across a good portion of the Inland NW, with lower
  amounts over the deeper Columbia Basin and higher amounts
  between 0.75 to 1.0 inch in the mountains. For areas the
  mountain snow this could translate to between 6 to 12 inches,
  while the lower elevations closer to the Cascades could see
  anywhere from a trace to a couple inches or so. These numbers,
  especially the lower elevation ones, will continue to be fine-
  tuned.

From Saturday evening into Sunday morning a secondary disturbance
slips by, renewing the precipitation threat outside of the
mountains. However precipitation amount as compared to Friday
night, look light. A third and more organized system comes in
sometime between Sunday and Monday morning. This taps some
subtropical moisture, but it is not as robust as the Friday night
system. Still models generate a modest precipitation threat across
all but the lee of the Cascades and deeper Basin. When and where
this develops is where model disagreement lingers. Most models
start precipitation early Sunday near Cascades. Yet farther east
some start it up through southeast WA and the central Panhandle in
the morning and others hold it off until afternoon. Chances remain
high outside of the lee of the Cascades and deeper Columbia Basin
through the evening, then dissipate overnight into Monday. Still
the leading edge of a fourth system, a warm front, approaches from
the west Monday afternoon. Whether moisture is deep enough to
allow precipitation to redevelop or just thickening clouds is even
less agreed upon. Chances will remain high near the Cascades and
lower elsewhere. As for snow levels through the period from
Saturday night through Monday, they waver between about 1500 and
3000 feet during the night and early morning hours and 2000 and
4000 feet during the day and early evening hours. The lowest of
those lay toward the northeast WA and north ID. This translates to
the potential for snow down to valley floors, especially at night,
and perhaps some light accumulations in the valleys. This includes
potentially the I-90 corridor, especially east of Ritzville and
the higher Palouse, as well as areas from the Waterville Plateau
north. /J. Cote`

Monday Night through Thursday: Pattern looks to remain active
early in the week as the moist northwesterly flow continues to
influence our weather. Exactly how long we remain active is up for
debate amongst the models at this point. The GFS brings an
offshore ridge near the west coast shifting the majority of the
atmospheric dynamics and moisture to the north ultimately leading
to a drier forecast. The ECMWF with support from the Canadian
model keeps the ridge further offshore and the opportunity for
precipitation alive much later into the week. At this point I have
leaned toward the Euro due to performance up to this point with
winter systems and kept POPs above climo through Wednesday. Along
with precip into the middle of the week, the Euro also brings
another round of cold continental polar air into the region
starting Wednesday sending our temperatures back below normal. In
turn the temperatures were trended down, but not yet to the full
extent of the ECMWF as I want just a bit more confidence. The
polar airmass is also quite dry so once the modified polar front
passes Wednesday, POPs drop off as well. Snow levels with the
precipitation in the extended forecast once again looks to sit
above most valley floors minus the far northern ones leading to
mainly a valley rain/mountain snow event. Higher benches such as
the West Plains, Upper Columbia Basin, etc. could see some snow
mix in overnight as our diurnal swings bottoms out. While this
forecast leaned more towards the Euro, model trends will have to
be closely monitored to better pin down the details as we near
this timeframe. /Fliehman

&&

.AVIATION...
06Z TAFS: A weak frontal boundary lifts into the region between
09-13Z spreading a wintry mix of light snow, sleet, and some
freezing rain. Accumulations, if any, are expected to be very
light. After the front moves off Thursday morning...a moist
boundary layer with weak upslope flow will maintain the threat of
MVFR ceilings over the eastern TAF sites. /sb

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        34  31  38  34  42  29 /  50  30  40 100  60  30
Coeur d`Alene  34  32  40  33  41  31 /  70  40  50 100  70  30
Pullman        39  29  42  35  42  32 /  60  10  20 100  70  30
Lewiston       40  31  45  39  47  35 /  80  10  10  80  50  30
Colville       34  26  38  34  43  26 /  50  40  70 100  40  30
Sandpoint      34  30  39  33  41  29 /  60  70  70 100  70  30
Kellogg        34  31  39  32  39  32 /  90  60  60 100  90  40
Moses Lake     35  21  37  31  47  28 /  60   0  70 100  30  20
Wenatchee      39  28  36  31  45  31 /  70   0  80 100  20  30
Omak           36  27  37  30  43  27 /  50  20  90 100  20  30

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Air Stagnation Advisory until Noon PST Friday for Central
     Panhandle Mountains-Coeur d`Alene Area-Idaho Palouse-
     Northern Panhandle.

     Winter Storm Watch from Friday afternoon through Saturday
     afternoon for Central Panhandle Mountains-Northern
     Panhandle.

WA...Air Stagnation Advisory until Noon PST Friday for East Slopes
     Northern Cascades-Lower Garfield and Asotin Counties-Moses
     Lake Area-Northeast Mountains-Okanogan Highlands-Spokane
     Area-Upper Columbia Basin-Washington Palouse-Waterville
     Plateau-Wenatchee Area.

     Winter Storm Watch from Friday afternoon through Saturday
     afternoon for Northeast Mountains-Okanogan Highlands.

     Winter Storm Watch from Friday morning through late Friday night
     for East Slopes Northern Cascades.

&&

$$




000
FXUS66 KOTX 201120
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
320 AM PST THU NOV 20 2014

.SYNOPSIS...
A weak weather system will arrive late tonight into Thursday with
the potential for a light wintry mix of rain...snow...and freezing
rain. A stronger, wetter and windier weather system will arrive
Friday persisting into the weekend with heavy snow amounts
possible over the mountains. The weather pattern will remain
active through the middle of next week.



&&

.DISCUSSION...

...Pockets of freezing rain possible this morning over the lower
Columbia Basin and portions of the Washington Palouse...

Today and tonight ...The ridge of the past week and a half is
becoming a relic of the past as disturbance number one (of many)
is currently passing through western Washington with its sights
set on the Inland Northwest. This disturbance is comprised of an
elongating band of moisture extending from a weak upper level low
just west of Vancouver Island southeast into in southwest Idaho.
Associated with this band of moisture was a weakening warm front
which will provide the focus for the weather today. Models have
remained rather consistent in taking this front from its current
position over south-central Washington northeast across the
remainder of eastern Washington and north Idaho today. The trend
of slowing the front continues...and now it looks like the front
won`t arrive into the northern tip of Idaho until around midday.

Forcing and lifting along the front looks rather weak...and it will
likely continue to diminish as it treks northeastward today.
Nonetheless...with a modified arctic air mass still firmly
entrenched over most of the region...it won`t take much lifting to
generate precipitation as the isentropic surfaces look rather
steep. That suggests most of the region will be subject to
precipitation today...but the question is what will it fall as.
This remains an exceedingly tricky forecast element. Model cross-
sections and 0-4km max wet-bulb temperatures continue to show an
elevated wedge of above freezing air over the extreme southern
portion of our forecast area. This encompasses the area generally
south of a line from Wenatchee to Moses Lake...then Pullman. Any
locations south of this line will be subject to light freezing
rain (with a small chance of sleet)...through this morning.
Meanwhile anything north will generally see snow. Again amounts
will be fairly light. Through the end of the day most locations
will see an tenth of an inch of precipitation or less. Snow
amounts will reflect this light precipitation with locations
generally seeing less than an inch. As for the freezing
rain...amounts will also be light...however any freezing rain can
result in potential travel difficulties. The potential for travel
problems will generally be confined to the morning hours as any
dirunal heating should bring road temperatures above freezing by
midday. Additionally...most of the precipitation threat also move
north and east of this elevated warm layer as well.

The front is expected to dissipate rapidly during the
evening...but that won`t be the end of the precipitation.
Initially upslope flow and residual frontal moisture will keep the
light snow falling over north Idaho...however things will
intensify somewhat overnight. This next round of precipitation
will be delivered care of the shortwave trough off of Vancouver
Island tracking through southern British Columbia overnight. The
lifting associated with this feature will not be strong...however
the atmosphere below 650 mbs or roughly 10k feet will become
saturated overnight. Renewed isentropic ascent...especially for
locations north of Highway 2 (in Washington) and I-90 (in
Idaho)...should result in a second round of precipitation. The
warm layer will surge a little farther north as well. By
morning...a shallow elevated melting layer could move as far north
as a Lake Chelan to Spokane line. This will be on the southern
edge of the next round of precipitation so there`s a small chance
of more freezing rain...however by that time...surface wet-bulb
temperatures are expected to near or exceed freezing...so main
precipitation would be rain or a rain snow mix for the Spokane
area and southeast sections of the Columbia Basin. For locations
over the northwest portion of the Basin...including Grand
Coulee...Wilbur...and Davenport there will be a small chance of
freezing rain. Confidence is not high however...as so much is
dependant on what happens today in terms of surface warming. If a
location gets above freezing today...it will likely remain that
way overnight as well. fx


...MODERATE TO HEAVY MOUNTAIN SNOW POSSIBLE LATE FRIDAY INTO
SATURDAY...

Friday through Monday: A series of systems slide across the
Inland NW, with several opportunities for rain and snow. First
early Friday the next system will be approaching. There will be a
threat of light snow or freezing rain/freezing drizzle across the
Upper Columbia Basin through northeast WA and north ID due to some
isentropic lift and low level moisture. The moisture is deepest
below about 650 to 700 mbs, below the core of the snow growth
zone. So this suggest the potential for a mixture of snow,
freezing rain or freezing drizzle, and rain as the precipitation
type. So we could be looking for some slick conditions along the
I-90/US-2/US-95 corridor in the morning.

Then Friday afternoon into Friday evening deepening isentropic
ascent and moisture noses across the Cascades into eastern WA and
north ID with the warm front. This will lead to increasing
precipitation from west to east, so that by early evening most of
Washington will be enveloped by it and by middle to late evening
much of Idaho will be too. Overnight the associated cold front
slips east of the Cascades, leading to dwindling precipitation in
the lee of the Cascades and western Columbia Basin. By late
Saturday morning to afternoon the highest threat briefly retreats
to the mountains, with winds becoming breezy to locally windy.
With the evolution discussed, the next questions surround snow
levels and precipitation amounts.

* Snow levels: The location of the snow hasn`t changed much from
  previous thinking. Based on wet-bulb zero heights, snow levels
  from Friday afternoon through Friday night will be around
  3000-4000 feet across the Cascades and northern mountains and
  4000 to 5000 feet southeast. However colder air trapped near the
  Cascades in the low level southeast flow will keep snow levels
  1500-3000 feet. This includes places in the lee of the Cascades,
  including the Okanogan Valley and Highlands through the
  Waterville Plateau and Wenatchee area. So the Cascades and areas
  the remaining mountain areas above 3000 to 4000 feet (except for
  the Blue Mountains where snow levels look too high to have much
  impact in the populated areas). Winter storm watches
  remain place for the Cascades and in the north WA and ID
  mountains above 4000 feet. We will monitor the potential need
  for advisories outside of the mountains, in the hills around the
  Okanogan Valley and Waterville Plateau and Wenatchee area.
  However accumulations may be limited if milder air is able to
  move in or precipitation amounts are not as high as expected.
  Behind the cold front going into Saturday afternoon snow levels
  drop to between 2500-3000 feet. So this means any lingering
  showers may be a mix of rain and snow, including as far south as
  the I-90 corridor. However by then the better precipitation
  threat starts that shift into the mountains.

* Precipitation amounts: Regional PWATs rise to between 0.45 to
  0.75 inches (or 130 to 200% of normal). So this is a juicy
  system and all models generate decent precipitation amounts. In
  the 24-hour period between Friday afternoon and Saturday
  afternoon models generate between 0.30 to 0.60 inches of liquid
  precipitation across a good portion of the Inland NW, with lower
  amounts over the deeper Columbia Basin and higher amounts
  between 0.75 to 1.0 inch in the mountains. For areas the
  mountain snow this could translate to between 6 to 12 inches,
  while the lower elevations closer to the Cascades could see
  anywhere from a trace to a couple inches or so. These numbers,
  especially the lower elevation ones, will continue to be fine-
  tuned.

From Saturday evening into Sunday morning a secondary disturbance
slips by, renewing the precipitation threat outside of the
mountains. However precipitation amount as compared to Friday
night, look light. A third and more organized system comes in
sometime between Sunday and Monday morning. This taps some
subtropical moisture, but it is not as robust as the Friday night
system. Still models generate a modest precipitation threat across
all but the lee of the Cascades and deeper Basin. When and where
this develops is where model disagreement lingers. Most models
start precipitation early Sunday near Cascades. Yet farther east
some start it up through southeast WA and the central Panhandle in
the morning and others hold it off until afternoon. Chances remain
high outside of the lee of the Cascades and deeper Columbia Basin
through the evening, then dissipate overnight into Monday. Still
the leading edge of a fourth system, a warm front, approaches from
the west Monday afternoon. Whether moisture is deep enough to
allow precipitation to redevelop or just thickening clouds is even
less agreed upon. Chances will remain high near the Cascades and
lower elsewhere. As for snow levels through the period from
Saturday night through Monday, they waver between about 1500 and
3000 feet during the night and early morning hours and 2000 and
4000 feet during the day and early evening hours. The lowest of
those lay toward the northeast WA and north ID. This translates to
the potential for snow down to valley floors, especially at night,
and perhaps some light accumulations in the valleys. This includes
potentially the I-90 corridor, especially east of Ritzville and
the higher Palouse, as well as areas from the Waterville Plateau
north. /J. Cote`

Monday Night through Thursday: Pattern looks to remain active
early in the week as the moist northwesterly flow continues to
influence our weather. Exactly how long we remain active is up for
debate amongst the models at this point. The GFS brings an
offshore ridge near the west coast shifting the majority of the
atmospheric dynamics and moisture to the north ultimately leading
to a drier forecast. The ECMWF with support from the Canadian
model keeps the ridge further offshore and the opportunity for
precipitation alive much later into the week. At this point I have
leaned toward the Euro due to performance up to this point with
winter systems and kept POPs above climo through Wednesday. Along
with precip into the middle of the week, the Euro also brings
another round of cold continental polar air into the region
starting Wednesday sending our temperatures back below normal. In
turn the temperatures were trended down, but not yet to the full
extent of the ECMWF as I want just a bit more confidence. The
polar airmass is also quite dry so once the modified polar front
passes Wednesday, POPs drop off as well. Snow levels with the
precipitation in the extended forecast once again looks to sit
above most valley floors minus the far northern ones leading to
mainly a valley rain/mountain snow event. Higher benches such as
the West Plains, Upper Columbia Basin, etc. could see some snow
mix in overnight as our diurnal swings bottoms out. While this
forecast leaned more towards the Euro, model trends will have to
be closely monitored to better pin down the details as we near
this timeframe. /Fliehman

&&

.AVIATION...
06Z TAFS: A weak frontal boundary lifts into the region between
09-13Z spreading a wintry mix of light snow, sleet, and some
freezing rain. Accumulations, if any, are expected to be very
light. After the front moves off Thursday morning...a moist
boundary layer with weak upslope flow will maintain the threat of
MVFR ceilings over the eastern TAF sites. /sb

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        34  31  38  34  42  29 /  50  30  40 100  60  30
Coeur d`Alene  34  32  40  33  41  31 /  70  40  50 100  70  30
Pullman        39  29  42  35  42  32 /  60  10  20 100  70  30
Lewiston       40  31  45  39  47  35 /  80  10  10  80  50  30
Colville       34  26  38  34  43  26 /  50  40  70 100  40  30
Sandpoint      34  30  39  33  41  29 /  60  70  70 100  70  30
Kellogg        34  31  39  32  39  32 /  90  60  60 100  90  40
Moses Lake     35  21  37  31  47  28 /  60   0  70 100  30  20
Wenatchee      39  28  36  31  45  31 /  70   0  80 100  20  30
Omak           36  27  37  30  43  27 /  50  20  90 100  20  30

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Air Stagnation Advisory until Noon PST Friday for Central
     Panhandle Mountains-Coeur d`Alene Area-Idaho Palouse-
     Northern Panhandle.

     Winter Storm Watch from Friday afternoon through Saturday
     afternoon for Central Panhandle Mountains-Northern
     Panhandle.

WA...Air Stagnation Advisory until Noon PST Friday for East Slopes
     Northern Cascades-Lower Garfield and Asotin Counties-Moses
     Lake Area-Northeast Mountains-Okanogan Highlands-Spokane
     Area-Upper Columbia Basin-Washington Palouse-Waterville
     Plateau-Wenatchee Area.

     Winter Storm Watch from Friday afternoon through Saturday
     afternoon for Northeast Mountains-Okanogan Highlands.

     Winter Storm Watch from Friday morning through late Friday night
     for East Slopes Northern Cascades.

&&

$$




000
FXUS66 KPQR 201103
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
255 AM PST THU NOV 20 2014

.SYNOPSIS...RAIN WILL DECREASE TODAY BUT THREAT OF FREEZING RAIN
REMAINS FOR THE COLUMBIA RIVER GORGE AND HOOD RIVER. A WELL
ORGANIZED MOIST FRONT WILL BRING HEAVIER RAIN AND GUSTY WINDS LATER
FRIDAY AND SATURDAY WITH RAIN AND MOUNTAIN SNOW SHOWERS CONTINUING
THROUGH THE WEEKEND. SNOW LEVELS WILL LIKELY LOWER BELOW THE CASCADE
PASSES BY SATURDAY.

&&

.SHORT TERM...TWO LOWS AFFECTING THE AREA TODAY AND TONIGHT.  THE
FIRST LOW IS NOW OFFSHORE OF VANCOUVER ISLAND. THIS LOW ROTATED A
WARM FRONT ACROSS THE AREA WED NIGHT AND THE PRECIPITATION FROM THIS
FRONT HAS EXITED TO THE NORTH. ANOTHER LOW NOW OFFSHORE OF THE N.
CALIFORNIA COAST WILL MAINTAIN MOIST SW FLOW AT THE LOW AND MID
LEVELS FOR CONTINUED THREAT OF SHOWERS TODAY.  THE MAIN DRIVE OF
THIS SYSTEM IS INTO SOUTHERN OREGON AND N. CALIFORNIA.

THE WEATHER IMPACT FOR TODAY IS IN THE COLUMBIA RIVER GORGE AND UPPER
HOOD RIVER VALLEY WHERE SHALLOW SUB FREEZING TEMPERATURES CONTINUE
EAST OF BONNEVILLE. QPF AMOUNTS VARIED WIDELY OVERNIGHT IN THE GORGE.
ABOUT 0.25 INCH FELL AT BONNEVILLE AND LESS THAN 0.1 INCH FOR THE
REMAINDER OF THE GORGE.  AT THIS TIME EXPECT NO MORE THAN ANOTHER
TENTH OF AN INCH TODAY AS PCPN SHOULD BE ENDING BY EARLY AFTERNOON.
IN ADDITION MUCH OF THE GORGE SHOULD CLIMB SLIGHTLY ABOVE FREEZING
TODAY. HOWEVER MUCH OF UPPER HOOD RIVER VALLEY WILL HAVE A TOUGH TIME
CLIMBING ABOVE THE FREEZING MARK.  SO HAVE EXTENDED THE FREEZING RAIN
ADVISORY THROUGH EARLY AFTERNOON...BUT AS MENTIONED ABOVE ADDITIONAL
FZRA ACCUMULATION WILL BE SMALL.  WITHOUT STRONG FORCING TO SCOUR
THE COLD AIR OUT OF THE EASTERN GORGE AND UPPER HOOD RIVER VALLEY
MAY SEE CONTINUED FREEZING TEMPERATURES INTO FRIDAY...WHICH MAY POSE
A REPEAT THREAT FOR FREEZING RAIN.  HOWEVER WITH LATEST MODEL RUNS
DELAY PCPN AND MID LEVEL WEST-SOUTHWEST WINDS ARE MUCH STRONGER SO
TEMPERATURES MAY MODERATE ABOVE FREEZING BY THE TIME PCPN STARTS.

AFTER BRIEF RIDGING LATER TODAY AND TONIGHT FOR A DRY PERIOD THE
DOORS OPEN TO A MORE ACTIVE AS THE NORTH PACIFIC JETSTREAM EXTENDS
TO THE PACNW.  A ROBUST FRONT ARRIVES FRIDAY BRINGING WINDY
CONDITIONS TO THE COAST AS WELL AS ABUNDANT RAIN ACROSS THE AREA.
NEW MODELS ARE SLIGHTLY SLOWER WITH THIS SYSTEM SO HAVE ADJUSTED
TIMING SLIGHTLY. THE BULK OF THE RAIN SHOULD FALL FRI AFTERNOON AND
EVENING. RIVERS WILL LIKELY MAKE A QUICK UPTURN BUT QPF AMOUNTS AND
DURATION INDICATE ACTION LEVELS ARE NOT LIKELY.

WINDY CONDITIONS FOR THE COAST ARE EXPECTED WITH A MARGINAL CASE FOR
HIGH WINDS AT THE COASTAL HEADLANDS.  00Z THU GFS AND NAM INCREASED
WINDS WITH THIS SYSTEM SO WILL WATCH FOR TRENDS AND RUN-TO-RUN
CONSISTENCY LEADING INTO WHETHER OR NOT HEADLINES WILL BE NEEDED. THE
00Z ECMWF ALSO CHANGED SHOWING POSSIBLE HIGH WINDS ON THE CENTRAL
COAST FRIDAY EVENING WITH DEEPENING LOW NEAR 991 MB NEAR ASTORIA BY
06Z SAT. THIS IS QUITE DIFFERENT THAN THE GFS/NAM SOLUTIONS BUT GIVEN
THE STRONG JETSTREAM POINTED TO THE PACNW AT THAT TIME STRONG
CYCLOGENSIS CAN NOT BE RULED OUT.

WHILE THE LOW LANDS WILL REMAIN MILD DURING THE UPCOMING PERIOD OF
ACTIVE WEATHER...THE CASCADES WILL BE RECEIVING SIGNIFICANT AMOUNTS
OF SNOW ESPECIALLY AFTER THE FRONT GOES THROUGH FRIDAY EVENING WHEN
SNOW LEVELS DROP TO BETWEEN 3500 AND 4500 FEET.  /26

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...SATURDAY NIGHT
THROUGH WEDNESDAY. THE MORE WESTERLY OR ZONAL FLOW THAT SETS UP LATE
IN THE SHORT TERM PERIOD CONTINUES INTO THE LONG TERM PERIOD...WITH
OCCASIONAL RAIN AS DISTURBANCES MOVE THROUGH. SOME RIDGING DEVELOPS
IN THE NORTHEAST PACIFIC EARLY NEXT WEEK...THOUGH THE MODELS VARY ON
HOW MUCH. THE NORMALLY MORE RELIABLE ECMWF MODEL HAS FLATTER RIDGING
WITH MORE OF A DIRTY RIDGE TYPE PATTERN AND DOES BRING SOME
PRECIPITATION INTO THE FORECAST AREA AT TIMES...WHILE THE OPERATIONAL
GFS MODEL SHOWS MORE AMPLITUDE DEVELOPING AND POSSIBLY SOME DRYING.
THE PARALLEL VERSION OF THE GFS MODEL IS A BIT MORE LIKE THE ECMWF.
HAVE KEPT OUR CURRENT TRENDS WHICH ARE MORE LIKE THE ECMWF AND THE
PARALLEL GFS MODEL...THOUGH CONFIDENCE IN ANY DETAILS ARE NOT VERY
HIGH AT THIS POINT. TOLLESON

&&

.AVIATION...SCATTERED SHOWERS ASSOCIATED WITH A WARM FRONT WILL
PERSIST THROUGH THIS AM...BRINGING A MIX OF MVFR AND IFR CIGS.
SOME IFR AND LIFR VIS IN PATCHY FOG/LOW STRATUS IS POSSIBLE
THROUGH 14-16Z THIS MORNING BEFORE MID CLOUDS INCREASE. OVERALL VFR
CONDITIONS EXPECTED BETWEEN 19-21Z TODAY. HOWEVER...THERE REMAINS
A CHANCE FOR RAIN AND MVFR CIGS INTO THIS AFTERNOON. GUSTY EAST
WINDS AT KTTD WILL PREVAIL THROUGH AROUND 16Z TODAY. MVFR TO IFR
CONDITIONS POSSIBLE LATE THURSDAY NIGHT ACROSS PORTIONS OF THE
SOUTH WILLAMETTE VALLEY.

KPDX AND APPROACHES...MVFR CIGS IN SHOWERS WILL LINGER THROUGH
18-20Z THIS MORNING THEN EXPECT VFR CONDITIONS TO PREVAIL. EAST
WINDS AROUND 15 KTS WILL PERSIST THROUGH AT LEAST 14Z THIS MORNING
BEFORE WEAKENING. /27

&&

.MARINE...SMALL CRAFT ADVISORY WINDS WITH GUSTS NEAR 25 KTS WILL
BRIEFLY WEAKEN THIS MORNING BEHIND A WEAK WARM FRONT...BEFORE
INCREASING AGAIN MIDDAY TODAY WITH THE APPROACH OF THE NEXT
FRONTAL SYSTEM. EXPECT ELEVATED SEAS THROUGH THIS AFTERNOON WITH
SEAS PEAKING AROUND 12 FT THIS MORNING.

STRONGER WEATHER SYSTEM WILL MOVE THROUGH ON FRIDAY. HIGH END
GALES WITH GUSTS NEAR 45-47 KTS ARE VERY POSSIBLE ON FRIDAY AHEAD
OF FRONTAL PASSAGE ACROSS OUR WATERS. SEAS TODAY WILL HOVER
AROUND 9 TO 10 FT BEFORE START TO BUILD AGAIN EARLY FRIDAY. WAVE
HEIGHTS WILL REACH THE MIDDLE TEENS BY MID-DAY FRIDAY AND COULD
EVEN GET INTO THE UPPER TEENS ACROSS THE SOUTHERN WATERS WITH GALE
FORCE WINDS POSSIBLE IN THIS AREA. WINDS AND SEAS WILL SUBSIDE
SATURDAY TO 10 TO 11 FT...AND SEAS LOOK TO REMAIN ABOVE 10 FT
THROUGH THE WEEKEND.

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING RAIN ADVISORY UNTIL 1 PM PST THIS AFTERNOON FOR CENTRAL

     COLUMBIA RIVER GORGE-UPPER HOOD RIVER VALLEY-WESTERN
     COLUMBIA RIVER GORGE.

WA...FREEZING RAIN ADVISORY UNTIL 1 PM PST THIS AFTERNOON FOR CENTRAL

     COLUMBIA RIVER GORGE-WESTERN COLUMBIA RIVER GORGE.

PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 7 AM PST THIS MORNING FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT 60
NM.

     SMALL CRAFT ADVISORY FOR WINDS FROM 10 AM THIS MORNING TO 4 AM
     PST FRIDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
     FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 3 PM PST THIS
     AFTERNOON FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
     FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 1 PM
     THIS AFTERNOON TO 6 PM PST THIS EVENING.

&&

$$

INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND

THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.



000
FXUS66 KPQR 201103
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
255 AM PST THU NOV 20 2014

.SYNOPSIS...RAIN WILL DECREASE TODAY BUT THREAT OF FREEZING RAIN
REMAINS FOR THE COLUMBIA RIVER GORGE AND HOOD RIVER. A WELL
ORGANIZED MOIST FRONT WILL BRING HEAVIER RAIN AND GUSTY WINDS LATER
FRIDAY AND SATURDAY WITH RAIN AND MOUNTAIN SNOW SHOWERS CONTINUING
THROUGH THE WEEKEND. SNOW LEVELS WILL LIKELY LOWER BELOW THE CASCADE
PASSES BY SATURDAY.

&&

.SHORT TERM...TWO LOWS AFFECTING THE AREA TODAY AND TONIGHT.  THE
FIRST LOW IS NOW OFFSHORE OF VANCOUVER ISLAND. THIS LOW ROTATED A
WARM FRONT ACROSS THE AREA WED NIGHT AND THE PRECIPITATION FROM THIS
FRONT HAS EXITED TO THE NORTH. ANOTHER LOW NOW OFFSHORE OF THE N.
CALIFORNIA COAST WILL MAINTAIN MOIST SW FLOW AT THE LOW AND MID
LEVELS FOR CONTINUED THREAT OF SHOWERS TODAY.  THE MAIN DRIVE OF
THIS SYSTEM IS INTO SOUTHERN OREGON AND N. CALIFORNIA.

THE WEATHER IMPACT FOR TODAY IS IN THE COLUMBIA RIVER GORGE AND UPPER
HOOD RIVER VALLEY WHERE SHALLOW SUB FREEZING TEMPERATURES CONTINUE
EAST OF BONNEVILLE. QPF AMOUNTS VARIED WIDELY OVERNIGHT IN THE GORGE.
ABOUT 0.25 INCH FELL AT BONNEVILLE AND LESS THAN 0.1 INCH FOR THE
REMAINDER OF THE GORGE.  AT THIS TIME EXPECT NO MORE THAN ANOTHER
TENTH OF AN INCH TODAY AS PCPN SHOULD BE ENDING BY EARLY AFTERNOON.
IN ADDITION MUCH OF THE GORGE SHOULD CLIMB SLIGHTLY ABOVE FREEZING
TODAY. HOWEVER MUCH OF UPPER HOOD RIVER VALLEY WILL HAVE A TOUGH TIME
CLIMBING ABOVE THE FREEZING MARK.  SO HAVE EXTENDED THE FREEZING RAIN
ADVISORY THROUGH EARLY AFTERNOON...BUT AS MENTIONED ABOVE ADDITIONAL
FZRA ACCUMULATION WILL BE SMALL.  WITHOUT STRONG FORCING TO SCOUR
THE COLD AIR OUT OF THE EASTERN GORGE AND UPPER HOOD RIVER VALLEY
MAY SEE CONTINUED FREEZING TEMPERATURES INTO FRIDAY...WHICH MAY POSE
A REPEAT THREAT FOR FREEZING RAIN.  HOWEVER WITH LATEST MODEL RUNS
DELAY PCPN AND MID LEVEL WEST-SOUTHWEST WINDS ARE MUCH STRONGER SO
TEMPERATURES MAY MODERATE ABOVE FREEZING BY THE TIME PCPN STARTS.

AFTER BRIEF RIDGING LATER TODAY AND TONIGHT FOR A DRY PERIOD THE
DOORS OPEN TO A MORE ACTIVE AS THE NORTH PACIFIC JETSTREAM EXTENDS
TO THE PACNW.  A ROBUST FRONT ARRIVES FRIDAY BRINGING WINDY
CONDITIONS TO THE COAST AS WELL AS ABUNDANT RAIN ACROSS THE AREA.
NEW MODELS ARE SLIGHTLY SLOWER WITH THIS SYSTEM SO HAVE ADJUSTED
TIMING SLIGHTLY. THE BULK OF THE RAIN SHOULD FALL FRI AFTERNOON AND
EVENING. RIVERS WILL LIKELY MAKE A QUICK UPTURN BUT QPF AMOUNTS AND
DURATION INDICATE ACTION LEVELS ARE NOT LIKELY.

WINDY CONDITIONS FOR THE COAST ARE EXPECTED WITH A MARGINAL CASE FOR
HIGH WINDS AT THE COASTAL HEADLANDS.  00Z THU GFS AND NAM INCREASED
WINDS WITH THIS SYSTEM SO WILL WATCH FOR TRENDS AND RUN-TO-RUN
CONSISTENCY LEADING INTO WHETHER OR NOT HEADLINES WILL BE NEEDED. THE
00Z ECMWF ALSO CHANGED SHOWING POSSIBLE HIGH WINDS ON THE CENTRAL
COAST FRIDAY EVENING WITH DEEPENING LOW NEAR 991 MB NEAR ASTORIA BY
06Z SAT. THIS IS QUITE DIFFERENT THAN THE GFS/NAM SOLUTIONS BUT GIVEN
THE STRONG JETSTREAM POINTED TO THE PACNW AT THAT TIME STRONG
CYCLOGENSIS CAN NOT BE RULED OUT.

WHILE THE LOW LANDS WILL REMAIN MILD DURING THE UPCOMING PERIOD OF
ACTIVE WEATHER...THE CASCADES WILL BE RECEIVING SIGNIFICANT AMOUNTS
OF SNOW ESPECIALLY AFTER THE FRONT GOES THROUGH FRIDAY EVENING WHEN
SNOW LEVELS DROP TO BETWEEN 3500 AND 4500 FEET.  /26

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...SATURDAY NIGHT
THROUGH WEDNESDAY. THE MORE WESTERLY OR ZONAL FLOW THAT SETS UP LATE
IN THE SHORT TERM PERIOD CONTINUES INTO THE LONG TERM PERIOD...WITH
OCCASIONAL RAIN AS DISTURBANCES MOVE THROUGH. SOME RIDGING DEVELOPS
IN THE NORTHEAST PACIFIC EARLY NEXT WEEK...THOUGH THE MODELS VARY ON
HOW MUCH. THE NORMALLY MORE RELIABLE ECMWF MODEL HAS FLATTER RIDGING
WITH MORE OF A DIRTY RIDGE TYPE PATTERN AND DOES BRING SOME
PRECIPITATION INTO THE FORECAST AREA AT TIMES...WHILE THE OPERATIONAL
GFS MODEL SHOWS MORE AMPLITUDE DEVELOPING AND POSSIBLY SOME DRYING.
THE PARALLEL VERSION OF THE GFS MODEL IS A BIT MORE LIKE THE ECMWF.
HAVE KEPT OUR CURRENT TRENDS WHICH ARE MORE LIKE THE ECMWF AND THE
PARALLEL GFS MODEL...THOUGH CONFIDENCE IN ANY DETAILS ARE NOT VERY
HIGH AT THIS POINT. TOLLESON

&&

.AVIATION...SCATTERED SHOWERS ASSOCIATED WITH A WARM FRONT WILL
PERSIST THROUGH THIS AM...BRINGING A MIX OF MVFR AND IFR CIGS.
SOME IFR AND LIFR VIS IN PATCHY FOG/LOW STRATUS IS POSSIBLE
THROUGH 14-16Z THIS MORNING BEFORE MID CLOUDS INCREASE. OVERALL VFR
CONDITIONS EXPECTED BETWEEN 19-21Z TODAY. HOWEVER...THERE REMAINS
A CHANCE FOR RAIN AND MVFR CIGS INTO THIS AFTERNOON. GUSTY EAST
WINDS AT KTTD WILL PREVAIL THROUGH AROUND 16Z TODAY. MVFR TO IFR
CONDITIONS POSSIBLE LATE THURSDAY NIGHT ACROSS PORTIONS OF THE
SOUTH WILLAMETTE VALLEY.

KPDX AND APPROACHES...MVFR CIGS IN SHOWERS WILL LINGER THROUGH
18-20Z THIS MORNING THEN EXPECT VFR CONDITIONS TO PREVAIL. EAST
WINDS AROUND 15 KTS WILL PERSIST THROUGH AT LEAST 14Z THIS MORNING
BEFORE WEAKENING. /27

&&

.MARINE...SMALL CRAFT ADVISORY WINDS WITH GUSTS NEAR 25 KTS WILL
BRIEFLY WEAKEN THIS MORNING BEHIND A WEAK WARM FRONT...BEFORE
INCREASING AGAIN MIDDAY TODAY WITH THE APPROACH OF THE NEXT
FRONTAL SYSTEM. EXPECT ELEVATED SEAS THROUGH THIS AFTERNOON WITH
SEAS PEAKING AROUND 12 FT THIS MORNING.

STRONGER WEATHER SYSTEM WILL MOVE THROUGH ON FRIDAY. HIGH END
GALES WITH GUSTS NEAR 45-47 KTS ARE VERY POSSIBLE ON FRIDAY AHEAD
OF FRONTAL PASSAGE ACROSS OUR WATERS. SEAS TODAY WILL HOVER
AROUND 9 TO 10 FT BEFORE START TO BUILD AGAIN EARLY FRIDAY. WAVE
HEIGHTS WILL REACH THE MIDDLE TEENS BY MID-DAY FRIDAY AND COULD
EVEN GET INTO THE UPPER TEENS ACROSS THE SOUTHERN WATERS WITH GALE
FORCE WINDS POSSIBLE IN THIS AREA. WINDS AND SEAS WILL SUBSIDE
SATURDAY TO 10 TO 11 FT...AND SEAS LOOK TO REMAIN ABOVE 10 FT
THROUGH THE WEEKEND.

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING RAIN ADVISORY UNTIL 1 PM PST THIS AFTERNOON FOR CENTRAL

     COLUMBIA RIVER GORGE-UPPER HOOD RIVER VALLEY-WESTERN
     COLUMBIA RIVER GORGE.

WA...FREEZING RAIN ADVISORY UNTIL 1 PM PST THIS AFTERNOON FOR CENTRAL

     COLUMBIA RIVER GORGE-WESTERN COLUMBIA RIVER GORGE.

PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 7 AM PST THIS MORNING FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT 60
NM.

     SMALL CRAFT ADVISORY FOR WINDS FROM 10 AM THIS MORNING TO 4 AM
     PST FRIDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
     FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 3 PM PST THIS
     AFTERNOON FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
     FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 1 PM
     THIS AFTERNOON TO 6 PM PST THIS EVENING.

&&

$$

INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND

THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.



000
FXUS66 KPQR 201103
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
255 AM PST THU NOV 20 2014

.SYNOPSIS...RAIN WILL DECREASE TODAY BUT THREAT OF FREEZING RAIN
REMAINS FOR THE COLUMBIA RIVER GORGE AND HOOD RIVER. A WELL
ORGANIZED MOIST FRONT WILL BRING HEAVIER RAIN AND GUSTY WINDS LATER
FRIDAY AND SATURDAY WITH RAIN AND MOUNTAIN SNOW SHOWERS CONTINUING
THROUGH THE WEEKEND. SNOW LEVELS WILL LIKELY LOWER BELOW THE CASCADE
PASSES BY SATURDAY.

&&

.SHORT TERM...TWO LOWS AFFECTING THE AREA TODAY AND TONIGHT.  THE
FIRST LOW IS NOW OFFSHORE OF VANCOUVER ISLAND. THIS LOW ROTATED A
WARM FRONT ACROSS THE AREA WED NIGHT AND THE PRECIPITATION FROM THIS
FRONT HAS EXITED TO THE NORTH. ANOTHER LOW NOW OFFSHORE OF THE N.
CALIFORNIA COAST WILL MAINTAIN MOIST SW FLOW AT THE LOW AND MID
LEVELS FOR CONTINUED THREAT OF SHOWERS TODAY.  THE MAIN DRIVE OF
THIS SYSTEM IS INTO SOUTHERN OREGON AND N. CALIFORNIA.

THE WEATHER IMPACT FOR TODAY IS IN THE COLUMBIA RIVER GORGE AND UPPER
HOOD RIVER VALLEY WHERE SHALLOW SUB FREEZING TEMPERATURES CONTINUE
EAST OF BONNEVILLE. QPF AMOUNTS VARIED WIDELY OVERNIGHT IN THE GORGE.
ABOUT 0.25 INCH FELL AT BONNEVILLE AND LESS THAN 0.1 INCH FOR THE
REMAINDER OF THE GORGE.  AT THIS TIME EXPECT NO MORE THAN ANOTHER
TENTH OF AN INCH TODAY AS PCPN SHOULD BE ENDING BY EARLY AFTERNOON.
IN ADDITION MUCH OF THE GORGE SHOULD CLIMB SLIGHTLY ABOVE FREEZING
TODAY. HOWEVER MUCH OF UPPER HOOD RIVER VALLEY WILL HAVE A TOUGH TIME
CLIMBING ABOVE THE FREEZING MARK.  SO HAVE EXTENDED THE FREEZING RAIN
ADVISORY THROUGH EARLY AFTERNOON...BUT AS MENTIONED ABOVE ADDITIONAL
FZRA ACCUMULATION WILL BE SMALL.  WITHOUT STRONG FORCING TO SCOUR
THE COLD AIR OUT OF THE EASTERN GORGE AND UPPER HOOD RIVER VALLEY
MAY SEE CONTINUED FREEZING TEMPERATURES INTO FRIDAY...WHICH MAY POSE
A REPEAT THREAT FOR FREEZING RAIN.  HOWEVER WITH LATEST MODEL RUNS
DELAY PCPN AND MID LEVEL WEST-SOUTHWEST WINDS ARE MUCH STRONGER SO
TEMPERATURES MAY MODERATE ABOVE FREEZING BY THE TIME PCPN STARTS.

AFTER BRIEF RIDGING LATER TODAY AND TONIGHT FOR A DRY PERIOD THE
DOORS OPEN TO A MORE ACTIVE AS THE NORTH PACIFIC JETSTREAM EXTENDS
TO THE PACNW.  A ROBUST FRONT ARRIVES FRIDAY BRINGING WINDY
CONDITIONS TO THE COAST AS WELL AS ABUNDANT RAIN ACROSS THE AREA.
NEW MODELS ARE SLIGHTLY SLOWER WITH THIS SYSTEM SO HAVE ADJUSTED
TIMING SLIGHTLY. THE BULK OF THE RAIN SHOULD FALL FRI AFTERNOON AND
EVENING. RIVERS WILL LIKELY MAKE A QUICK UPTURN BUT QPF AMOUNTS AND
DURATION INDICATE ACTION LEVELS ARE NOT LIKELY.

WINDY CONDITIONS FOR THE COAST ARE EXPECTED WITH A MARGINAL CASE FOR
HIGH WINDS AT THE COASTAL HEADLANDS.  00Z THU GFS AND NAM INCREASED
WINDS WITH THIS SYSTEM SO WILL WATCH FOR TRENDS AND RUN-TO-RUN
CONSISTENCY LEADING INTO WHETHER OR NOT HEADLINES WILL BE NEEDED. THE
00Z ECMWF ALSO CHANGED SHOWING POSSIBLE HIGH WINDS ON THE CENTRAL
COAST FRIDAY EVENING WITH DEEPENING LOW NEAR 991 MB NEAR ASTORIA BY
06Z SAT. THIS IS QUITE DIFFERENT THAN THE GFS/NAM SOLUTIONS BUT GIVEN
THE STRONG JETSTREAM POINTED TO THE PACNW AT THAT TIME STRONG
CYCLOGENSIS CAN NOT BE RULED OUT.

WHILE THE LOW LANDS WILL REMAIN MILD DURING THE UPCOMING PERIOD OF
ACTIVE WEATHER...THE CASCADES WILL BE RECEIVING SIGNIFICANT AMOUNTS
OF SNOW ESPECIALLY AFTER THE FRONT GOES THROUGH FRIDAY EVENING WHEN
SNOW LEVELS DROP TO BETWEEN 3500 AND 4500 FEET.  /26

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...SATURDAY NIGHT
THROUGH WEDNESDAY. THE MORE WESTERLY OR ZONAL FLOW THAT SETS UP LATE
IN THE SHORT TERM PERIOD CONTINUES INTO THE LONG TERM PERIOD...WITH
OCCASIONAL RAIN AS DISTURBANCES MOVE THROUGH. SOME RIDGING DEVELOPS
IN THE NORTHEAST PACIFIC EARLY NEXT WEEK...THOUGH THE MODELS VARY ON
HOW MUCH. THE NORMALLY MORE RELIABLE ECMWF MODEL HAS FLATTER RIDGING
WITH MORE OF A DIRTY RIDGE TYPE PATTERN AND DOES BRING SOME
PRECIPITATION INTO THE FORECAST AREA AT TIMES...WHILE THE OPERATIONAL
GFS MODEL SHOWS MORE AMPLITUDE DEVELOPING AND POSSIBLY SOME DRYING.
THE PARALLEL VERSION OF THE GFS MODEL IS A BIT MORE LIKE THE ECMWF.
HAVE KEPT OUR CURRENT TRENDS WHICH ARE MORE LIKE THE ECMWF AND THE
PARALLEL GFS MODEL...THOUGH CONFIDENCE IN ANY DETAILS ARE NOT VERY
HIGH AT THIS POINT. TOLLESON

&&

.AVIATION...SCATTERED SHOWERS ASSOCIATED WITH A WARM FRONT WILL
PERSIST THROUGH THIS AM...BRINGING A MIX OF MVFR AND IFR CIGS.
SOME IFR AND LIFR VIS IN PATCHY FOG/LOW STRATUS IS POSSIBLE
THROUGH 14-16Z THIS MORNING BEFORE MID CLOUDS INCREASE. OVERALL VFR
CONDITIONS EXPECTED BETWEEN 19-21Z TODAY. HOWEVER...THERE REMAINS
A CHANCE FOR RAIN AND MVFR CIGS INTO THIS AFTERNOON. GUSTY EAST
WINDS AT KTTD WILL PREVAIL THROUGH AROUND 16Z TODAY. MVFR TO IFR
CONDITIONS POSSIBLE LATE THURSDAY NIGHT ACROSS PORTIONS OF THE
SOUTH WILLAMETTE VALLEY.

KPDX AND APPROACHES...MVFR CIGS IN SHOWERS WILL LINGER THROUGH
18-20Z THIS MORNING THEN EXPECT VFR CONDITIONS TO PREVAIL. EAST
WINDS AROUND 15 KTS WILL PERSIST THROUGH AT LEAST 14Z THIS MORNING
BEFORE WEAKENING. /27

&&

.MARINE...SMALL CRAFT ADVISORY WINDS WITH GUSTS NEAR 25 KTS WILL
BRIEFLY WEAKEN THIS MORNING BEHIND A WEAK WARM FRONT...BEFORE
INCREASING AGAIN MIDDAY TODAY WITH THE APPROACH OF THE NEXT
FRONTAL SYSTEM. EXPECT ELEVATED SEAS THROUGH THIS AFTERNOON WITH
SEAS PEAKING AROUND 12 FT THIS MORNING.

STRONGER WEATHER SYSTEM WILL MOVE THROUGH ON FRIDAY. HIGH END
GALES WITH GUSTS NEAR 45-47 KTS ARE VERY POSSIBLE ON FRIDAY AHEAD
OF FRONTAL PASSAGE ACROSS OUR WATERS. SEAS TODAY WILL HOVER
AROUND 9 TO 10 FT BEFORE START TO BUILD AGAIN EARLY FRIDAY. WAVE
HEIGHTS WILL REACH THE MIDDLE TEENS BY MID-DAY FRIDAY AND COULD
EVEN GET INTO THE UPPER TEENS ACROSS THE SOUTHERN WATERS WITH GALE
FORCE WINDS POSSIBLE IN THIS AREA. WINDS AND SEAS WILL SUBSIDE
SATURDAY TO 10 TO 11 FT...AND SEAS LOOK TO REMAIN ABOVE 10 FT
THROUGH THE WEEKEND.

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING RAIN ADVISORY UNTIL 1 PM PST THIS AFTERNOON FOR CENTRAL

     COLUMBIA RIVER GORGE-UPPER HOOD RIVER VALLEY-WESTERN
     COLUMBIA RIVER GORGE.

WA...FREEZING RAIN ADVISORY UNTIL 1 PM PST THIS AFTERNOON FOR CENTRAL

     COLUMBIA RIVER GORGE-WESTERN COLUMBIA RIVER GORGE.

PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 7 AM PST THIS MORNING FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT 60
NM.

     SMALL CRAFT ADVISORY FOR WINDS FROM 10 AM THIS MORNING TO 4 AM
     PST FRIDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
     FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 3 PM PST THIS
     AFTERNOON FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
     FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 1 PM
     THIS AFTERNOON TO 6 PM PST THIS EVENING.

&&

$$

INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND

THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.



000
FXUS66 KPQR 201103
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
255 AM PST THU NOV 20 2014

.SYNOPSIS...RAIN WILL DECREASE TODAY BUT THREAT OF FREEZING RAIN
REMAINS FOR THE COLUMBIA RIVER GORGE AND HOOD RIVER. A WELL
ORGANIZED MOIST FRONT WILL BRING HEAVIER RAIN AND GUSTY WINDS LATER
FRIDAY AND SATURDAY WITH RAIN AND MOUNTAIN SNOW SHOWERS CONTINUING
THROUGH THE WEEKEND. SNOW LEVELS WILL LIKELY LOWER BELOW THE CASCADE
PASSES BY SATURDAY.

&&

.SHORT TERM...TWO LOWS AFFECTING THE AREA TODAY AND TONIGHT.  THE
FIRST LOW IS NOW OFFSHORE OF VANCOUVER ISLAND. THIS LOW ROTATED A
WARM FRONT ACROSS THE AREA WED NIGHT AND THE PRECIPITATION FROM THIS
FRONT HAS EXITED TO THE NORTH. ANOTHER LOW NOW OFFSHORE OF THE N.
CALIFORNIA COAST WILL MAINTAIN MOIST SW FLOW AT THE LOW AND MID
LEVELS FOR CONTINUED THREAT OF SHOWERS TODAY.  THE MAIN DRIVE OF
THIS SYSTEM IS INTO SOUTHERN OREGON AND N. CALIFORNIA.

THE WEATHER IMPACT FOR TODAY IS IN THE COLUMBIA RIVER GORGE AND UPPER
HOOD RIVER VALLEY WHERE SHALLOW SUB FREEZING TEMPERATURES CONTINUE
EAST OF BONNEVILLE. QPF AMOUNTS VARIED WIDELY OVERNIGHT IN THE GORGE.
ABOUT 0.25 INCH FELL AT BONNEVILLE AND LESS THAN 0.1 INCH FOR THE
REMAINDER OF THE GORGE.  AT THIS TIME EXPECT NO MORE THAN ANOTHER
TENTH OF AN INCH TODAY AS PCPN SHOULD BE ENDING BY EARLY AFTERNOON.
IN ADDITION MUCH OF THE GORGE SHOULD CLIMB SLIGHTLY ABOVE FREEZING
TODAY. HOWEVER MUCH OF UPPER HOOD RIVER VALLEY WILL HAVE A TOUGH TIME
CLIMBING ABOVE THE FREEZING MARK.  SO HAVE EXTENDED THE FREEZING RAIN
ADVISORY THROUGH EARLY AFTERNOON...BUT AS MENTIONED ABOVE ADDITIONAL
FZRA ACCUMULATION WILL BE SMALL.  WITHOUT STRONG FORCING TO SCOUR
THE COLD AIR OUT OF THE EASTERN GORGE AND UPPER HOOD RIVER VALLEY
MAY SEE CONTINUED FREEZING TEMPERATURES INTO FRIDAY...WHICH MAY POSE
A REPEAT THREAT FOR FREEZING RAIN.  HOWEVER WITH LATEST MODEL RUNS
DELAY PCPN AND MID LEVEL WEST-SOUTHWEST WINDS ARE MUCH STRONGER SO
TEMPERATURES MAY MODERATE ABOVE FREEZING BY THE TIME PCPN STARTS.

AFTER BRIEF RIDGING LATER TODAY AND TONIGHT FOR A DRY PERIOD THE
DOORS OPEN TO A MORE ACTIVE AS THE NORTH PACIFIC JETSTREAM EXTENDS
TO THE PACNW.  A ROBUST FRONT ARRIVES FRIDAY BRINGING WINDY
CONDITIONS TO THE COAST AS WELL AS ABUNDANT RAIN ACROSS THE AREA.
NEW MODELS ARE SLIGHTLY SLOWER WITH THIS SYSTEM SO HAVE ADJUSTED
TIMING SLIGHTLY. THE BULK OF THE RAIN SHOULD FALL FRI AFTERNOON AND
EVENING. RIVERS WILL LIKELY MAKE A QUICK UPTURN BUT QPF AMOUNTS AND
DURATION INDICATE ACTION LEVELS ARE NOT LIKELY.

WINDY CONDITIONS FOR THE COAST ARE EXPECTED WITH A MARGINAL CASE FOR
HIGH WINDS AT THE COASTAL HEADLANDS.  00Z THU GFS AND NAM INCREASED
WINDS WITH THIS SYSTEM SO WILL WATCH FOR TRENDS AND RUN-TO-RUN
CONSISTENCY LEADING INTO WHETHER OR NOT HEADLINES WILL BE NEEDED. THE
00Z ECMWF ALSO CHANGED SHOWING POSSIBLE HIGH WINDS ON THE CENTRAL
COAST FRIDAY EVENING WITH DEEPENING LOW NEAR 991 MB NEAR ASTORIA BY
06Z SAT. THIS IS QUITE DIFFERENT THAN THE GFS/NAM SOLUTIONS BUT GIVEN
THE STRONG JETSTREAM POINTED TO THE PACNW AT THAT TIME STRONG
CYCLOGENSIS CAN NOT BE RULED OUT.

WHILE THE LOW LANDS WILL REMAIN MILD DURING THE UPCOMING PERIOD OF
ACTIVE WEATHER...THE CASCADES WILL BE RECEIVING SIGNIFICANT AMOUNTS
OF SNOW ESPECIALLY AFTER THE FRONT GOES THROUGH FRIDAY EVENING WHEN
SNOW LEVELS DROP TO BETWEEN 3500 AND 4500 FEET.  /26

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...SATURDAY NIGHT
THROUGH WEDNESDAY. THE MORE WESTERLY OR ZONAL FLOW THAT SETS UP LATE
IN THE SHORT TERM PERIOD CONTINUES INTO THE LONG TERM PERIOD...WITH
OCCASIONAL RAIN AS DISTURBANCES MOVE THROUGH. SOME RIDGING DEVELOPS
IN THE NORTHEAST PACIFIC EARLY NEXT WEEK...THOUGH THE MODELS VARY ON
HOW MUCH. THE NORMALLY MORE RELIABLE ECMWF MODEL HAS FLATTER RIDGING
WITH MORE OF A DIRTY RIDGE TYPE PATTERN AND DOES BRING SOME
PRECIPITATION INTO THE FORECAST AREA AT TIMES...WHILE THE OPERATIONAL
GFS MODEL SHOWS MORE AMPLITUDE DEVELOPING AND POSSIBLY SOME DRYING.
THE PARALLEL VERSION OF THE GFS MODEL IS A BIT MORE LIKE THE ECMWF.
HAVE KEPT OUR CURRENT TRENDS WHICH ARE MORE LIKE THE ECMWF AND THE
PARALLEL GFS MODEL...THOUGH CONFIDENCE IN ANY DETAILS ARE NOT VERY
HIGH AT THIS POINT. TOLLESON

&&

.AVIATION...SCATTERED SHOWERS ASSOCIATED WITH A WARM FRONT WILL
PERSIST THROUGH THIS AM...BRINGING A MIX OF MVFR AND IFR CIGS.
SOME IFR AND LIFR VIS IN PATCHY FOG/LOW STRATUS IS POSSIBLE
THROUGH 14-16Z THIS MORNING BEFORE MID CLOUDS INCREASE. OVERALL VFR
CONDITIONS EXPECTED BETWEEN 19-21Z TODAY. HOWEVER...THERE REMAINS
A CHANCE FOR RAIN AND MVFR CIGS INTO THIS AFTERNOON. GUSTY EAST
WINDS AT KTTD WILL PREVAIL THROUGH AROUND 16Z TODAY. MVFR TO IFR
CONDITIONS POSSIBLE LATE THURSDAY NIGHT ACROSS PORTIONS OF THE
SOUTH WILLAMETTE VALLEY.

KPDX AND APPROACHES...MVFR CIGS IN SHOWERS WILL LINGER THROUGH
18-20Z THIS MORNING THEN EXPECT VFR CONDITIONS TO PREVAIL. EAST
WINDS AROUND 15 KTS WILL PERSIST THROUGH AT LEAST 14Z THIS MORNING
BEFORE WEAKENING. /27

&&

.MARINE...SMALL CRAFT ADVISORY WINDS WITH GUSTS NEAR 25 KTS WILL
BRIEFLY WEAKEN THIS MORNING BEHIND A WEAK WARM FRONT...BEFORE
INCREASING AGAIN MIDDAY TODAY WITH THE APPROACH OF THE NEXT
FRONTAL SYSTEM. EXPECT ELEVATED SEAS THROUGH THIS AFTERNOON WITH
SEAS PEAKING AROUND 12 FT THIS MORNING.

STRONGER WEATHER SYSTEM WILL MOVE THROUGH ON FRIDAY. HIGH END
GALES WITH GUSTS NEAR 45-47 KTS ARE VERY POSSIBLE ON FRIDAY AHEAD
OF FRONTAL PASSAGE ACROSS OUR WATERS. SEAS TODAY WILL HOVER
AROUND 9 TO 10 FT BEFORE START TO BUILD AGAIN EARLY FRIDAY. WAVE
HEIGHTS WILL REACH THE MIDDLE TEENS BY MID-DAY FRIDAY AND COULD
EVEN GET INTO THE UPPER TEENS ACROSS THE SOUTHERN WATERS WITH GALE
FORCE WINDS POSSIBLE IN THIS AREA. WINDS AND SEAS WILL SUBSIDE
SATURDAY TO 10 TO 11 FT...AND SEAS LOOK TO REMAIN ABOVE 10 FT
THROUGH THE WEEKEND.

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING RAIN ADVISORY UNTIL 1 PM PST THIS AFTERNOON FOR CENTRAL

     COLUMBIA RIVER GORGE-UPPER HOOD RIVER VALLEY-WESTERN
     COLUMBIA RIVER GORGE.

WA...FREEZING RAIN ADVISORY UNTIL 1 PM PST THIS AFTERNOON FOR CENTRAL

     COLUMBIA RIVER GORGE-WESTERN COLUMBIA RIVER GORGE.

PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 7 AM PST THIS MORNING FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT 60
NM.

     SMALL CRAFT ADVISORY FOR WINDS FROM 10 AM THIS MORNING TO 4 AM
     PST FRIDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
     FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 3 PM PST THIS
     AFTERNOON FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
     FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 1 PM
     THIS AFTERNOON TO 6 PM PST THIS EVENING.

&&

$$

INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND

THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.



000
FXUS66 KOTX 200614
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
1013 PM PST WED NOV 19 2014

.SYNOPSIS...
A weak weather system will arrive late tonight into Thursday with
the potential for a light wintry mix of rain...snow...and freezing
rain. A stronger, wetter and windier weather system will arrive
Friday persisting into the weekend with heavy snow amounts
possible over the mountains. The weather pattern will remain
active through the middle of next week.


&&

.DISCUSSION...

...SLICK TRAVEL EXPECTED OVER SOUTHEASTERN WA ALONG HIGHWAY 26 and
HIGHWAY 12 DUE TO FREEZING RAIN AND SLEET EARLY THURSDAY MORNING...

...A MIX OF LIGHT SNOW AND SLEET POSSIBLE DURING THE MORNING
COMMUTE IN EASTERN WA AND NORTHERN IDAHO...

Evening update: A tricky yet low precipitation event will pass
through the region early Thursday morning and depart in the
afternoon. At this time, it looks like the best chance for
freezing rain mixing with sleet will be over southeastern WA from
northern Garfield County into southwestern Whitman...and southern
Adams County. These areas are currently in the mid 20s and model
profiles are most favorable for a these precipitation types.
Amounts are the unknown factor with the last few runs of the HRRR
simulated reflectivity trending toward the drier NAM. This will
mean the potential ranging from a trace to few hundreths of
liquid. Slick conditions a strong possibility for the Thursday
morning commute but anticipated ice accumulations remains in low
confidence. Nonetheless, Highway 26 and Highway 12 look to carry
the highest threat for icy roads from freezing rain/sleet.

The further north you travel from Pullman to Spokane-CDA-Kellogg-
St Maries. The chance for precipitation to remain as snow becomes
much better. My guess is areas of Benewah/Latah/Kootenai/Shoshone
County will stand the best chance for up to an inch of snow with
less than a half an inch into Spokane, NE WA, and far northern ID
Panhandle. One reason is the lack of QPF but a second will be low
snow ratios. KOTX sounding indicated the top of the inversion
layer around +3C. While this will wetbulb below freezing to
support snow, snowflakes will undergo some melting/rounding and
just having a hard time supporting snow ratios above 10:1. If
precipitation intensity is higher than expected, this could yield
slightly higher amounts. Another factor is temperatures are
currently above freezing between Pullman and Lewiston. Local
downsloping this afternoon warmed temperatures into the 40`s.
Dewpoints remain dry enough to support wetbulbing near to below
freezing but not by much and if precip intensity remains light,
this may never occur. On the other end of the spectrum, it is
still only 9PM and precipitation will not arrive until 5AM so
there is still time to cool but increasing clouds does not favor
any big drops.

Further west, a passing trace to hundreth is expected as the
frontal occlusion lifts north. Models do not show much in the way
of QPF from Wenatchee to Omak but dynamics are a bit stronger on
this side of the CWA so will leave some chance for snow with
amounts generally between a trace and tenth. Up to an inch will be
possible in the mountains and across the Cascade Passes.

&&

.AVIATION...
06Z TAFS: A weak frontal boundary lifts into the region between
09-13Z spreading a wintry mix of light snow, sleet, and some
freezing rain. Accumulations, if any, are expected to be very
light. After the front moves off Thursday morning...a moist
boundary layer with weak upslope flow will maintain the threat of
MVFR ceilings over the eastern TAF sites. /sb



&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        23  34  31  38  34  42 /  10  70  20  40  90  40
Coeur d`Alene  23  34  32  40  34  41 /  10  70  30  50  90  70
Pullman        31  39  29  42  35  42 /  20  80  20  20  90  70
Lewiston       33  40  31  44  40  47 /  30  80  10  10  80  50
Colville       22  34  26  38  36  42 /   0  30  30  70 100  40
Sandpoint      21  34  30  40  34  41 /   0  50  50  70 100  60
Kellogg        25  34  31  38  34  38 /  10  80  40  50  90  90
Moses Lake     24  35  21  37  31  48 /  40  20  10  70 100  20
Wenatchee      29  39  28  35  33  46 /  50  20  10  80 100  20
Omak           24  36  27  36  31  43 /  10  20  10  80 100  20

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Air Stagnation Advisory until Noon PST Friday for Central
     Panhandle Mountains-Coeur d`Alene Area-Idaho Palouse-
     Northern Panhandle.

     Winter Storm Watch from Friday afternoon through Saturday
     afternoon for Central Panhandle Mountains-Northern
     Panhandle.

WA...Air Stagnation Advisory until Noon PST Friday for East Slopes
     Northern Cascades-Lower Garfield and Asotin Counties-Moses
     Lake Area-Northeast Mountains-Okanogan Highlands-Spokane
     Area-Upper Columbia Basin-Washington Palouse-Waterville
     Plateau-Wenatchee Area.

     Winter Storm Watch from Friday afternoon through Saturday
     afternoon for Northeast Mountains-Okanogan Highlands.

     Winter Storm Watch from Friday morning through late Friday night
     for East Slopes Northern Cascades.

&&

$$





000
FXUS66 KOTX 200614
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
1013 PM PST WED NOV 19 2014

.SYNOPSIS...
A weak weather system will arrive late tonight into Thursday with
the potential for a light wintry mix of rain...snow...and freezing
rain. A stronger, wetter and windier weather system will arrive
Friday persisting into the weekend with heavy snow amounts
possible over the mountains. The weather pattern will remain
active through the middle of next week.


&&

.DISCUSSION...

...SLICK TRAVEL EXPECTED OVER SOUTHEASTERN WA ALONG HIGHWAY 26 and
HIGHWAY 12 DUE TO FREEZING RAIN AND SLEET EARLY THURSDAY MORNING...

...A MIX OF LIGHT SNOW AND SLEET POSSIBLE DURING THE MORNING
COMMUTE IN EASTERN WA AND NORTHERN IDAHO...

Evening update: A tricky yet low precipitation event will pass
through the region early Thursday morning and depart in the
afternoon. At this time, it looks like the best chance for
freezing rain mixing with sleet will be over southeastern WA from
northern Garfield County into southwestern Whitman...and southern
Adams County. These areas are currently in the mid 20s and model
profiles are most favorable for a these precipitation types.
Amounts are the unknown factor with the last few runs of the HRRR
simulated reflectivity trending toward the drier NAM. This will
mean the potential ranging from a trace to few hundreths of
liquid. Slick conditions a strong possibility for the Thursday
morning commute but anticipated ice accumulations remains in low
confidence. Nonetheless, Highway 26 and Highway 12 look to carry
the highest threat for icy roads from freezing rain/sleet.

The further north you travel from Pullman to Spokane-CDA-Kellogg-
St Maries. The chance for precipitation to remain as snow becomes
much better. My guess is areas of Benewah/Latah/Kootenai/Shoshone
County will stand the best chance for up to an inch of snow with
less than a half an inch into Spokane, NE WA, and far northern ID
Panhandle. One reason is the lack of QPF but a second will be low
snow ratios. KOTX sounding indicated the top of the inversion
layer around +3C. While this will wetbulb below freezing to
support snow, snowflakes will undergo some melting/rounding and
just having a hard time supporting snow ratios above 10:1. If
precipitation intensity is higher than expected, this could yield
slightly higher amounts. Another factor is temperatures are
currently above freezing between Pullman and Lewiston. Local
downsloping this afternoon warmed temperatures into the 40`s.
Dewpoints remain dry enough to support wetbulbing near to below
freezing but not by much and if precip intensity remains light,
this may never occur. On the other end of the spectrum, it is
still only 9PM and precipitation will not arrive until 5AM so
there is still time to cool but increasing clouds does not favor
any big drops.

Further west, a passing trace to hundreth is expected as the
frontal occlusion lifts north. Models do not show much in the way
of QPF from Wenatchee to Omak but dynamics are a bit stronger on
this side of the CWA so will leave some chance for snow with
amounts generally between a trace and tenth. Up to an inch will be
possible in the mountains and across the Cascade Passes.

&&

.AVIATION...
06Z TAFS: A weak frontal boundary lifts into the region between
09-13Z spreading a wintry mix of light snow, sleet, and some
freezing rain. Accumulations, if any, are expected to be very
light. After the front moves off Thursday morning...a moist
boundary layer with weak upslope flow will maintain the threat of
MVFR ceilings over the eastern TAF sites. /sb



&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        23  34  31  38  34  42 /  10  70  20  40  90  40
Coeur d`Alene  23  34  32  40  34  41 /  10  70  30  50  90  70
Pullman        31  39  29  42  35  42 /  20  80  20  20  90  70
Lewiston       33  40  31  44  40  47 /  30  80  10  10  80  50
Colville       22  34  26  38  36  42 /   0  30  30  70 100  40
Sandpoint      21  34  30  40  34  41 /   0  50  50  70 100  60
Kellogg        25  34  31  38  34  38 /  10  80  40  50  90  90
Moses Lake     24  35  21  37  31  48 /  40  20  10  70 100  20
Wenatchee      29  39  28  35  33  46 /  50  20  10  80 100  20
Omak           24  36  27  36  31  43 /  10  20  10  80 100  20

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Air Stagnation Advisory until Noon PST Friday for Central
     Panhandle Mountains-Coeur d`Alene Area-Idaho Palouse-
     Northern Panhandle.

     Winter Storm Watch from Friday afternoon through Saturday
     afternoon for Central Panhandle Mountains-Northern
     Panhandle.

WA...Air Stagnation Advisory until Noon PST Friday for East Slopes
     Northern Cascades-Lower Garfield and Asotin Counties-Moses
     Lake Area-Northeast Mountains-Okanogan Highlands-Spokane
     Area-Upper Columbia Basin-Washington Palouse-Waterville
     Plateau-Wenatchee Area.

     Winter Storm Watch from Friday afternoon through Saturday
     afternoon for Northeast Mountains-Okanogan Highlands.

     Winter Storm Watch from Friday morning through late Friday night
     for East Slopes Northern Cascades.

&&

$$





000
FXUS66 KOTX 200614
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
1013 PM PST WED NOV 19 2014

.SYNOPSIS...
A weak weather system will arrive late tonight into Thursday with
the potential for a light wintry mix of rain...snow...and freezing
rain. A stronger, wetter and windier weather system will arrive
Friday persisting into the weekend with heavy snow amounts
possible over the mountains. The weather pattern will remain
active through the middle of next week.


&&

.DISCUSSION...

...SLICK TRAVEL EXPECTED OVER SOUTHEASTERN WA ALONG HIGHWAY 26 and
HIGHWAY 12 DUE TO FREEZING RAIN AND SLEET EARLY THURSDAY MORNING...

...A MIX OF LIGHT SNOW AND SLEET POSSIBLE DURING THE MORNING
COMMUTE IN EASTERN WA AND NORTHERN IDAHO...

Evening update: A tricky yet low precipitation event will pass
through the region early Thursday morning and depart in the
afternoon. At this time, it looks like the best chance for
freezing rain mixing with sleet will be over southeastern WA from
northern Garfield County into southwestern Whitman...and southern
Adams County. These areas are currently in the mid 20s and model
profiles are most favorable for a these precipitation types.
Amounts are the unknown factor with the last few runs of the HRRR
simulated reflectivity trending toward the drier NAM. This will
mean the potential ranging from a trace to few hundreths of
liquid. Slick conditions a strong possibility for the Thursday
morning commute but anticipated ice accumulations remains in low
confidence. Nonetheless, Highway 26 and Highway 12 look to carry
the highest threat for icy roads from freezing rain/sleet.

The further north you travel from Pullman to Spokane-CDA-Kellogg-
St Maries. The chance for precipitation to remain as snow becomes
much better. My guess is areas of Benewah/Latah/Kootenai/Shoshone
County will stand the best chance for up to an inch of snow with
less than a half an inch into Spokane, NE WA, and far northern ID
Panhandle. One reason is the lack of QPF but a second will be low
snow ratios. KOTX sounding indicated the top of the inversion
layer around +3C. While this will wetbulb below freezing to
support snow, snowflakes will undergo some melting/rounding and
just having a hard time supporting snow ratios above 10:1. If
precipitation intensity is higher than expected, this could yield
slightly higher amounts. Another factor is temperatures are
currently above freezing between Pullman and Lewiston. Local
downsloping this afternoon warmed temperatures into the 40`s.
Dewpoints remain dry enough to support wetbulbing near to below
freezing but not by much and if precip intensity remains light,
this may never occur. On the other end of the spectrum, it is
still only 9PM and precipitation will not arrive until 5AM so
there is still time to cool but increasing clouds does not favor
any big drops.

Further west, a passing trace to hundreth is expected as the
frontal occlusion lifts north. Models do not show much in the way
of QPF from Wenatchee to Omak but dynamics are a bit stronger on
this side of the CWA so will leave some chance for snow with
amounts generally between a trace and tenth. Up to an inch will be
possible in the mountains and across the Cascade Passes.

&&

.AVIATION...
06Z TAFS: A weak frontal boundary lifts into the region between
09-13Z spreading a wintry mix of light snow, sleet, and some
freezing rain. Accumulations, if any, are expected to be very
light. After the front moves off Thursday morning...a moist
boundary layer with weak upslope flow will maintain the threat of
MVFR ceilings over the eastern TAF sites. /sb



&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        23  34  31  38  34  42 /  10  70  20  40  90  40
Coeur d`Alene  23  34  32  40  34  41 /  10  70  30  50  90  70
Pullman        31  39  29  42  35  42 /  20  80  20  20  90  70
Lewiston       33  40  31  44  40  47 /  30  80  10  10  80  50
Colville       22  34  26  38  36  42 /   0  30  30  70 100  40
Sandpoint      21  34  30  40  34  41 /   0  50  50  70 100  60
Kellogg        25  34  31  38  34  38 /  10  80  40  50  90  90
Moses Lake     24  35  21  37  31  48 /  40  20  10  70 100  20
Wenatchee      29  39  28  35  33  46 /  50  20  10  80 100  20
Omak           24  36  27  36  31  43 /  10  20  10  80 100  20

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Air Stagnation Advisory until Noon PST Friday for Central
     Panhandle Mountains-Coeur d`Alene Area-Idaho Palouse-
     Northern Panhandle.

     Winter Storm Watch from Friday afternoon through Saturday
     afternoon for Central Panhandle Mountains-Northern
     Panhandle.

WA...Air Stagnation Advisory until Noon PST Friday for East Slopes
     Northern Cascades-Lower Garfield and Asotin Counties-Moses
     Lake Area-Northeast Mountains-Okanogan Highlands-Spokane
     Area-Upper Columbia Basin-Washington Palouse-Waterville
     Plateau-Wenatchee Area.

     Winter Storm Watch from Friday afternoon through Saturday
     afternoon for Northeast Mountains-Okanogan Highlands.

     Winter Storm Watch from Friday morning through late Friday night
     for East Slopes Northern Cascades.

&&

$$





000
FXUS66 KOTX 200614
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
1013 PM PST WED NOV 19 2014

.SYNOPSIS...
A weak weather system will arrive late tonight into Thursday with
the potential for a light wintry mix of rain...snow...and freezing
rain. A stronger, wetter and windier weather system will arrive
Friday persisting into the weekend with heavy snow amounts
possible over the mountains. The weather pattern will remain
active through the middle of next week.


&&

.DISCUSSION...

...SLICK TRAVEL EXPECTED OVER SOUTHEASTERN WA ALONG HIGHWAY 26 and
HIGHWAY 12 DUE TO FREEZING RAIN AND SLEET EARLY THURSDAY MORNING...

...A MIX OF LIGHT SNOW AND SLEET POSSIBLE DURING THE MORNING
COMMUTE IN EASTERN WA AND NORTHERN IDAHO...

Evening update: A tricky yet low precipitation event will pass
through the region early Thursday morning and depart in the
afternoon. At this time, it looks like the best chance for
freezing rain mixing with sleet will be over southeastern WA from
northern Garfield County into southwestern Whitman...and southern
Adams County. These areas are currently in the mid 20s and model
profiles are most favorable for a these precipitation types.
Amounts are the unknown factor with the last few runs of the HRRR
simulated reflectivity trending toward the drier NAM. This will
mean the potential ranging from a trace to few hundreths of
liquid. Slick conditions a strong possibility for the Thursday
morning commute but anticipated ice accumulations remains in low
confidence. Nonetheless, Highway 26 and Highway 12 look to carry
the highest threat for icy roads from freezing rain/sleet.

The further north you travel from Pullman to Spokane-CDA-Kellogg-
St Maries. The chance for precipitation to remain as snow becomes
much better. My guess is areas of Benewah/Latah/Kootenai/Shoshone
County will stand the best chance for up to an inch of snow with
less than a half an inch into Spokane, NE WA, and far northern ID
Panhandle. One reason is the lack of QPF but a second will be low
snow ratios. KOTX sounding indicated the top of the inversion
layer around +3C. While this will wetbulb below freezing to
support snow, snowflakes will undergo some melting/rounding and
just having a hard time supporting snow ratios above 10:1. If
precipitation intensity is higher than expected, this could yield
slightly higher amounts. Another factor is temperatures are
currently above freezing between Pullman and Lewiston. Local
downsloping this afternoon warmed temperatures into the 40`s.
Dewpoints remain dry enough to support wetbulbing near to below
freezing but not by much and if precip intensity remains light,
this may never occur. On the other end of the spectrum, it is
still only 9PM and precipitation will not arrive until 5AM so
there is still time to cool but increasing clouds does not favor
any big drops.

Further west, a passing trace to hundreth is expected as the
frontal occlusion lifts north. Models do not show much in the way
of QPF from Wenatchee to Omak but dynamics are a bit stronger on
this side of the CWA so will leave some chance for snow with
amounts generally between a trace and tenth. Up to an inch will be
possible in the mountains and across the Cascade Passes.

&&

.AVIATION...
06Z TAFS: A weak frontal boundary lifts into the region between
09-13Z spreading a wintry mix of light snow, sleet, and some
freezing rain. Accumulations, if any, are expected to be very
light. After the front moves off Thursday morning...a moist
boundary layer with weak upslope flow will maintain the threat of
MVFR ceilings over the eastern TAF sites. /sb



&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        23  34  31  38  34  42 /  10  70  20  40  90  40
Coeur d`Alene  23  34  32  40  34  41 /  10  70  30  50  90  70
Pullman        31  39  29  42  35  42 /  20  80  20  20  90  70
Lewiston       33  40  31  44  40  47 /  30  80  10  10  80  50
Colville       22  34  26  38  36  42 /   0  30  30  70 100  40
Sandpoint      21  34  30  40  34  41 /   0  50  50  70 100  60
Kellogg        25  34  31  38  34  38 /  10  80  40  50  90  90
Moses Lake     24  35  21  37  31  48 /  40  20  10  70 100  20
Wenatchee      29  39  28  35  33  46 /  50  20  10  80 100  20
Omak           24  36  27  36  31  43 /  10  20  10  80 100  20

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Air Stagnation Advisory until Noon PST Friday for Central
     Panhandle Mountains-Coeur d`Alene Area-Idaho Palouse-
     Northern Panhandle.

     Winter Storm Watch from Friday afternoon through Saturday
     afternoon for Central Panhandle Mountains-Northern
     Panhandle.

WA...Air Stagnation Advisory until Noon PST Friday for East Slopes
     Northern Cascades-Lower Garfield and Asotin Counties-Moses
     Lake Area-Northeast Mountains-Okanogan Highlands-Spokane
     Area-Upper Columbia Basin-Washington Palouse-Waterville
     Plateau-Wenatchee Area.

     Winter Storm Watch from Friday afternoon through Saturday
     afternoon for Northeast Mountains-Okanogan Highlands.

     Winter Storm Watch from Friday morning through late Friday night
     for East Slopes Northern Cascades.

&&

$$





000
FXUS66 KPQR 200542
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
942 PM PST WED NOV 19 2014

.SYNOPSIS...RAIN WILL PUSH TO THE NORTHEAST ACROSS THE REGION TONIGHT
WITH FREEZING RAIN FOR THE COLUMBIA RIVER GORGE  AND HOOD RIVER. RAIN
SHOWERS WILL CONTINUE THURSDAY MORNING...EASING IN THE AFTERNOON AND
EVENING. A WELL ORGANIZED MOIST FRONT WILL BRING HEAVIER RAIN AND
GUSTY WIND FRIDAY NIGHT AND SATURDAY WITH RAIN AND MOUNTAIN SNOW
SHOWERS CONTINUING THROUGH THE WEEKEND. SNOW LEVELS WILL LIKELY LOWER
BELOW THE CASCADE PASSES SATURDAY.

&&

.UPDATE...SATELLITE AND RADAR IMAGERY SHOWS A FRONT CURRENTLY DRAPED
ACROSS NW OREGON FROM TILLAMOOK TO OAKRIDGE. THE FRONT AND ASSOCIATED
RAIN IS MOVING TO THE NW. AS OF 8 PM...THE LEADING EDGE OF THE RAIN
IS JUST REACHING ASTORIA...THE PORTLAND METRO AREA AND GOVERNMENT
CAMP. THE REAR EDGE OF THE RAIN IS ACROSS LINCOLN
CITY...CORVALLIS...AND SANTIAM JUNCTION. RAINFALL SO FAR HAS BEEN
HEAVIEST FOR THE CENTRAL OREGON COAST RANGE WHERE A QUARTER OF AN
INCH OF RAIN FELL...IN THE HILLS WEST OF EUGENE. OTHERWISE RAIN HAS
BEEN BETWEEN 0.05 AND 0.15 INCH.

SURFACE OBSERVATIONS AND WEB CAMS SUGGEST THAT THE SNOW LEVEL IS WELL
ABOVE THE CASCADE PASSES. TEMPERATURES IN THE NORTHER OREGON AND
SOUTH WASHINGTON CASCADES HAVE DROPPED SINCE SUNSET WITH MANY
LOCATIONS...ESPECIALLY IN THE LOWER ELEVATIONS ARE STILL BELOW OR
NEAR FREEZING. THE RAIN FRONT HAS WARMED TEMPERATURES WHERE IT PASSED
THIS AFTERNOON...BUT THE WARMING WILL BE LESS QUICK NOW THAT IT IS
NIGHT TIME. THEREFORE...EXPECT SOME AREAS OF FREEZING RAIN IN THE
EXTREME NORTHERN OREGON CASCADES AND THE SW WASHINGTON CASCADES FOR
THE LOWER ELEVATIONS BEFORE TURNING TO ALL RAIN.

THE EAST WINDS ARE FINALLY STARTING TO EASE...WITH THE TROUTDALE TO
DALLES SURFACE PRESSURE GRADIENT DROPPED BELOW 10 MB EARLIER THIS
EVENING. GUSTY EAST WINDS WILL GRADUALLY DECREASE AND THE GUSTS
SHOULD BE BELOW 30 MPH THURSDAY MORNING. WITH THAT SAID...THE CENTRAL
COLUMBIA RIVER GORGE AND THE UPPER HOOD RIVER VALLEY ARE STILL VERY
COLD...WITH TEMPERATURES BELOW FREEZING. RADAR SHOWS THE RAIN IS JUST
ABOUT TO REACH THAT AREA AND EXPECT THE MAIN PRECIPITATION TYPE WILL
BE FREEZING RAIN. WILL CONTINUE THE FREEZING RAIN ADVISORY FOR
TONIGHT. TRAPPED COLD AIR USUALLY TAKES MORE TIME THAN THE MODELS OR
WE THINK TO WARM...ESPECIALLY WITH A DEEP LAYER OF COLD AIR...AND
THERE IS A CHANCE THAT THE ADVISORY WILL NEED TO BE EXTENDED INTO THE
AFTERNOON. HAVE DECIDED TO WAIT TO SEE HOW THE RAIN MODIFIES THE
TEMPERATURES BEFORE ALTERING THE END END TIME OF THE ADVISORY. TJ

...FROM PREVIOUS SHORT TERM DISCUSSION...EXPECT THE PRIMARY THREAT TO
BE OVER BY 12Z/4AM THURSDAY BUT DO EXPECT FURTHER VERY LIGHT
ACCUMULATIONS THROUGH A LARGE PART OF THE DAY ACROSS THE ENTIRE AREA
AS ANOTHER DEVELOPING SHORT WAVE WILL LARGELY SLIDE SOUTH OF OUR AREA
AND MAINLY INTO NORTHERN CALIFORNIA. THERE WILL BE AREAS OF
DEFORMATION OVER US TO PRODUCE MORE OF A HYBRID STRATIFORM/SHOWER
PRECIP SCENARIO. SNOW LEVELS WILL BEGIN RISING RAPIDLY BY EARLY
FRIDAY AS WARM FRONTAL RAIN UNDER MOIST ZONAL PACIFIC FLOW SPREADS
FROM WEST TO EAST. BY THEMSELVES...QPF AMOUNTS ARE FAIRLY MODEST BUT
DO APPROACH AN INCH ENDING SATURDAY EVENING FOR THE VALLEYS AND A
LITTLE OVER 2 INCHES FOR THE CASCADES AND COAST RANGE. SNOW LEVELS
STAY HIGH UNTIL THE COLD FRONT DOES CROSS OVERNIGHT FRIDAY NIGHT.
EXPECT TO SEE A FEW INCHES OF PASS LEVEL ACCUMULATION LATER FRIDAY
AND FRIDAY NIGHT JUST AHEAD OF THE FRONT BUT THE MOISTURE EASES AFTER
THE FRONT WITH SNOW LEVELS FALLING TO AROUND 3000 FEET. HAVE ISSUED A
SPECIAL WEATHER STATEMENT FOR THE EXPECTED SNOW THIS WEEKEND.

AS MENTIONED PREVIOUSLY...DONT YET HAVE MUCH FAITH IN MODELED GORGE
TEMPERATURES RISING ABOVE FREEZING UNTIL PERHAPS LATER FRIDAY NIGHT
OR SATURDAY MORNING WHEN THE SURFACE PRESSURE GRADIENT TRULY BECOMES
WESTERLY. EXPERIENCE SHOWS MODELS ATTEMPT TO WARM UP THE GORGE BY
MIXING FROM ABOVE BUT THE COLDER DENSER AIR FROM EAST OF THE
CASCADES COMMONLY UNDERCUTS THAT MIXED LAYER UNTIL A SOLID WESTERLY
WIND PUSHES THROUGH THE LOWEST TERRAIN. AS SUCH WILL BE KEEPING A
CLOSE EYE ON WHAT ACTUALLY OCCURS TONIGHT AND EARLY TOMORROW. IF THE
HUNCH IS CORRECT...THE INCOMING SYSTEM FRIDAY COULD PRESENT A
SIGNIFICANT THREAT FOR AN ICE STORM COVERING AT LEAST THE CENTRAL
GORGE AND HOOD RIVER VALLEY...IF NOT THE WESTERN GORGE AS WELL. THE
ONE FACTOR IN FAVOR OF THE WARMING IS WE ARE STILL ON THE DOWNWARD
GLIDE SLOPE HEADING INTO CALENDAR WINTER. DECIDED TO HOLD OFF AND
TOW THE MODEL LINE REGARDING IMPROVING TEMPERATURES FOR NOW BUT
EXPECT THAT IF CONDITIONS REMAIN SUB-FREEZING NEAR AND EAST OF HOOD
RIVER...FRIDAY NIGHT COULD BE FAIRLY ICY. /JBONK

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...SATURDAY NIGHT
THROUGH WEDNESDAY. THE MORE WESTERLY OR
ZONAL FLOW THAT SETS UP LATE IN THE SHORT TERM PERIOD CONTINUES INTO
THE LONG TERM PERIOD...WITH OCCASIONAL RAIN AS DISTURBANCES MOVE
THROUGH. SOME RIDGING DEVELOPS IN THE NORTHEAST PACIFIC EARLY NEXT
WEEK...THOUGH THE MODELS VARY ON HOW MUCH. THE NORMALLY MORE RELIABLE
ECMWF MODEL HAS FLATTER RIDGING WITH MORE OF A DIRTY RIDGE TYPE
PATTERN AND DOES BRING SOME PRECIPITATION INTO THE FORECAST AREA AT
TIMES...WHILE THE OPERATIONAL GFS MODEL SHOWS MORE AMPLITUDE
DEVELOPING AND POSSIBLY SOME DRYING. THE PARALLEL VERSION OF THE GFS
MODEL IS A BIT MORE LIKE THE ECMWF. HAVE KEPT OUR CURRENT TRENDS
WHICH ARE MORE LIKE THE ECMWF AND THE PARALLEL GFS MODEL...THOUGH
CONFIDENCE IN ANY DETAILS ARE NOT VERY HIGH AT THIS POINT. TOLLESON
&&

.AVIATION...THE WARM FRONT IS CURRENTLY MOVING THROUGH THE REGION
WITH RAIN EXTENDING ALONG A LINE FROM KTMK SOUTHWEST TOWARDS LINN
COUNTY. EXPECT MAINLY MVFR CONDITIONS WITH LOWER CIGS THROUGH
THURSDAY MORNING. VFR CONDITIONS EXPECTED LATE THURSDAY MORNING.
HOWEVER...THERE REMAINS A CHANCE FOR RAIN AND MVFR CIGS INTO
THURSDAY AFTERNOON. GUSTY EAST WINDS AT KTTD WILL PREVAIL THROUGH
AROUND 13Z THURSDAY. MVFR TO IFR CONDITIONS POSSIBLE LATE THURSDAY
NIGHT ACROSS PORTIONS OF THE SOUTH WILLAMETTE VALLEY.


KPDX AND APPROACHES...VFR CONDITIONS WILL PREVAIL INTO THURSDAY
MORNING. THERE IS AN INCREASING CHANCE FOR RAIN AFTER 12Z THURSDAY
WHICH MAY BRING PERIODS OF MVFR TO IFR CONDITIONS.

&&

.MARINE...A WEAK WARM FRONT MOVED ACROSS THE WATERS THIS EVENING
BRINGING WITH IT SMALL CRAFT ADVISORY WINDS AND SEAS. EXPECT
ELEVATED SEAS THROUGH THURSDAY AFTERNOON WITH SEAS PEAKING AROUND
12 FT EARLY THURSDAY MORNING. WINDS WILL REMAIN NEAR SMALL CRAFT
ADVISORY INTO FRIDAY MORNING...BUT WILL WEAKEN BRIEFLY ON THURSDAY
MORNING.

STRONGER WEATHER SYSTEM WILL MOVE THROUGH ON FRIDAY. GALES ARE
VERY POSSIBLE ON FRIDAY AHEAD OF FRONTAL PASSAGE ACROSS OUR
WATERS. THURSDAY SEAS WILL HOVER AROUND 9 TO 10 FT BEFORE START TO
BUILD AGAIN EARLY FRIDAY. WAVE HEIGHTS WILL REACH THE MIDDLE TEENS
BY MID-DAY FRIDAY AND COULD EVEN GET INTO THE UPPER TEENS ACROSS
THE SOUTHERN WATERS WITH GALE FORCE WINDS POSSIBLE IN THIS AREA.
WINDS AND SEAS WILL SUBSIDE SATURDAY TO 10 TO 11 FT...AND SEAS
LOOK TO REMAIN ABOVE 10 FT THROUGH THE WEEKEND.

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING RAIN ADVISORY UNTIL 4 AM PST THURSDAY FOR CENTRAL
     COLUMBIA RIVER GORGE-UPPER HOOD RIVER VALLEY-WESTERN
     COLUMBIA RIVER GORGE.

WA...FREEZING RAIN ADVISORY UNTIL 4 AM PST THURSDAY FOR CENTRAL
     COLUMBIA RIVER GORGE-WESTERN COLUMBIA RIVER GORGE.

PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 7 AM PST THURSDAY FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR
     OUT 60 NM.

     SMALL CRAFT ADVISORY FOR WINDS FROM 10 AM THURSDAY TO 4 AM PST
     FRIDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR

     OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 3 PM PST THURSDAY
     FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT
     60 NM.

     SMALL CRAFT ADVISORY FOR WINDS UNTIL 2 AM PST THURSDAY FOR
     COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 1 PM TO
     6 PM PST THURSDAY.

&&


$$

INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND

THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.




000
FXUS66 KPQR 200542
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
942 PM PST WED NOV 19 2014

.SYNOPSIS...RAIN WILL PUSH TO THE NORTHEAST ACROSS THE REGION TONIGHT
WITH FREEZING RAIN FOR THE COLUMBIA RIVER GORGE  AND HOOD RIVER. RAIN
SHOWERS WILL CONTINUE THURSDAY MORNING...EASING IN THE AFTERNOON AND
EVENING. A WELL ORGANIZED MOIST FRONT WILL BRING HEAVIER RAIN AND
GUSTY WIND FRIDAY NIGHT AND SATURDAY WITH RAIN AND MOUNTAIN SNOW
SHOWERS CONTINUING THROUGH THE WEEKEND. SNOW LEVELS WILL LIKELY LOWER
BELOW THE CASCADE PASSES SATURDAY.

&&

.UPDATE...SATELLITE AND RADAR IMAGERY SHOWS A FRONT CURRENTLY DRAPED
ACROSS NW OREGON FROM TILLAMOOK TO OAKRIDGE. THE FRONT AND ASSOCIATED
RAIN IS MOVING TO THE NW. AS OF 8 PM...THE LEADING EDGE OF THE RAIN
IS JUST REACHING ASTORIA...THE PORTLAND METRO AREA AND GOVERNMENT
CAMP. THE REAR EDGE OF THE RAIN IS ACROSS LINCOLN
CITY...CORVALLIS...AND SANTIAM JUNCTION. RAINFALL SO FAR HAS BEEN
HEAVIEST FOR THE CENTRAL OREGON COAST RANGE WHERE A QUARTER OF AN
INCH OF RAIN FELL...IN THE HILLS WEST OF EUGENE. OTHERWISE RAIN HAS
BEEN BETWEEN 0.05 AND 0.15 INCH.

SURFACE OBSERVATIONS AND WEB CAMS SUGGEST THAT THE SNOW LEVEL IS WELL
ABOVE THE CASCADE PASSES. TEMPERATURES IN THE NORTHER OREGON AND
SOUTH WASHINGTON CASCADES HAVE DROPPED SINCE SUNSET WITH MANY
LOCATIONS...ESPECIALLY IN THE LOWER ELEVATIONS ARE STILL BELOW OR
NEAR FREEZING. THE RAIN FRONT HAS WARMED TEMPERATURES WHERE IT PASSED
THIS AFTERNOON...BUT THE WARMING WILL BE LESS QUICK NOW THAT IT IS
NIGHT TIME. THEREFORE...EXPECT SOME AREAS OF FREEZING RAIN IN THE
EXTREME NORTHERN OREGON CASCADES AND THE SW WASHINGTON CASCADES FOR
THE LOWER ELEVATIONS BEFORE TURNING TO ALL RAIN.

THE EAST WINDS ARE FINALLY STARTING TO EASE...WITH THE TROUTDALE TO
DALLES SURFACE PRESSURE GRADIENT DROPPED BELOW 10 MB EARLIER THIS
EVENING. GUSTY EAST WINDS WILL GRADUALLY DECREASE AND THE GUSTS
SHOULD BE BELOW 30 MPH THURSDAY MORNING. WITH THAT SAID...THE CENTRAL
COLUMBIA RIVER GORGE AND THE UPPER HOOD RIVER VALLEY ARE STILL VERY
COLD...WITH TEMPERATURES BELOW FREEZING. RADAR SHOWS THE RAIN IS JUST
ABOUT TO REACH THAT AREA AND EXPECT THE MAIN PRECIPITATION TYPE WILL
BE FREEZING RAIN. WILL CONTINUE THE FREEZING RAIN ADVISORY FOR
TONIGHT. TRAPPED COLD AIR USUALLY TAKES MORE TIME THAN THE MODELS OR
WE THINK TO WARM...ESPECIALLY WITH A DEEP LAYER OF COLD AIR...AND
THERE IS A CHANCE THAT THE ADVISORY WILL NEED TO BE EXTENDED INTO THE
AFTERNOON. HAVE DECIDED TO WAIT TO SEE HOW THE RAIN MODIFIES THE
TEMPERATURES BEFORE ALTERING THE END END TIME OF THE ADVISORY. TJ

...FROM PREVIOUS SHORT TERM DISCUSSION...EXPECT THE PRIMARY THREAT TO
BE OVER BY 12Z/4AM THURSDAY BUT DO EXPECT FURTHER VERY LIGHT
ACCUMULATIONS THROUGH A LARGE PART OF THE DAY ACROSS THE ENTIRE AREA
AS ANOTHER DEVELOPING SHORT WAVE WILL LARGELY SLIDE SOUTH OF OUR AREA
AND MAINLY INTO NORTHERN CALIFORNIA. THERE WILL BE AREAS OF
DEFORMATION OVER US TO PRODUCE MORE OF A HYBRID STRATIFORM/SHOWER
PRECIP SCENARIO. SNOW LEVELS WILL BEGIN RISING RAPIDLY BY EARLY
FRIDAY AS WARM FRONTAL RAIN UNDER MOIST ZONAL PACIFIC FLOW SPREADS
FROM WEST TO EAST. BY THEMSELVES...QPF AMOUNTS ARE FAIRLY MODEST BUT
DO APPROACH AN INCH ENDING SATURDAY EVENING FOR THE VALLEYS AND A
LITTLE OVER 2 INCHES FOR THE CASCADES AND COAST RANGE. SNOW LEVELS
STAY HIGH UNTIL THE COLD FRONT DOES CROSS OVERNIGHT FRIDAY NIGHT.
EXPECT TO SEE A FEW INCHES OF PASS LEVEL ACCUMULATION LATER FRIDAY
AND FRIDAY NIGHT JUST AHEAD OF THE FRONT BUT THE MOISTURE EASES AFTER
THE FRONT WITH SNOW LEVELS FALLING TO AROUND 3000 FEET. HAVE ISSUED A
SPECIAL WEATHER STATEMENT FOR THE EXPECTED SNOW THIS WEEKEND.

AS MENTIONED PREVIOUSLY...DONT YET HAVE MUCH FAITH IN MODELED GORGE
TEMPERATURES RISING ABOVE FREEZING UNTIL PERHAPS LATER FRIDAY NIGHT
OR SATURDAY MORNING WHEN THE SURFACE PRESSURE GRADIENT TRULY BECOMES
WESTERLY. EXPERIENCE SHOWS MODELS ATTEMPT TO WARM UP THE GORGE BY
MIXING FROM ABOVE BUT THE COLDER DENSER AIR FROM EAST OF THE
CASCADES COMMONLY UNDERCUTS THAT MIXED LAYER UNTIL A SOLID WESTERLY
WIND PUSHES THROUGH THE LOWEST TERRAIN. AS SUCH WILL BE KEEPING A
CLOSE EYE ON WHAT ACTUALLY OCCURS TONIGHT AND EARLY TOMORROW. IF THE
HUNCH IS CORRECT...THE INCOMING SYSTEM FRIDAY COULD PRESENT A
SIGNIFICANT THREAT FOR AN ICE STORM COVERING AT LEAST THE CENTRAL
GORGE AND HOOD RIVER VALLEY...IF NOT THE WESTERN GORGE AS WELL. THE
ONE FACTOR IN FAVOR OF THE WARMING IS WE ARE STILL ON THE DOWNWARD
GLIDE SLOPE HEADING INTO CALENDAR WINTER. DECIDED TO HOLD OFF AND
TOW THE MODEL LINE REGARDING IMPROVING TEMPERATURES FOR NOW BUT
EXPECT THAT IF CONDITIONS REMAIN SUB-FREEZING NEAR AND EAST OF HOOD
RIVER...FRIDAY NIGHT COULD BE FAIRLY ICY. /JBONK

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...SATURDAY NIGHT
THROUGH WEDNESDAY. THE MORE WESTERLY OR
ZONAL FLOW THAT SETS UP LATE IN THE SHORT TERM PERIOD CONTINUES INTO
THE LONG TERM PERIOD...WITH OCCASIONAL RAIN AS DISTURBANCES MOVE
THROUGH. SOME RIDGING DEVELOPS IN THE NORTHEAST PACIFIC EARLY NEXT
WEEK...THOUGH THE MODELS VARY ON HOW MUCH. THE NORMALLY MORE RELIABLE
ECMWF MODEL HAS FLATTER RIDGING WITH MORE OF A DIRTY RIDGE TYPE
PATTERN AND DOES BRING SOME PRECIPITATION INTO THE FORECAST AREA AT
TIMES...WHILE THE OPERATIONAL GFS MODEL SHOWS MORE AMPLITUDE
DEVELOPING AND POSSIBLY SOME DRYING. THE PARALLEL VERSION OF THE GFS
MODEL IS A BIT MORE LIKE THE ECMWF. HAVE KEPT OUR CURRENT TRENDS
WHICH ARE MORE LIKE THE ECMWF AND THE PARALLEL GFS MODEL...THOUGH
CONFIDENCE IN ANY DETAILS ARE NOT VERY HIGH AT THIS POINT. TOLLESON
&&

.AVIATION...THE WARM FRONT IS CURRENTLY MOVING THROUGH THE REGION
WITH RAIN EXTENDING ALONG A LINE FROM KTMK SOUTHWEST TOWARDS LINN
COUNTY. EXPECT MAINLY MVFR CONDITIONS WITH LOWER CIGS THROUGH
THURSDAY MORNING. VFR CONDITIONS EXPECTED LATE THURSDAY MORNING.
HOWEVER...THERE REMAINS A CHANCE FOR RAIN AND MVFR CIGS INTO
THURSDAY AFTERNOON. GUSTY EAST WINDS AT KTTD WILL PREVAIL THROUGH
AROUND 13Z THURSDAY. MVFR TO IFR CONDITIONS POSSIBLE LATE THURSDAY
NIGHT ACROSS PORTIONS OF THE SOUTH WILLAMETTE VALLEY.


KPDX AND APPROACHES...VFR CONDITIONS WILL PREVAIL INTO THURSDAY
MORNING. THERE IS AN INCREASING CHANCE FOR RAIN AFTER 12Z THURSDAY
WHICH MAY BRING PERIODS OF MVFR TO IFR CONDITIONS.

&&

.MARINE...A WEAK WARM FRONT MOVED ACROSS THE WATERS THIS EVENING
BRINGING WITH IT SMALL CRAFT ADVISORY WINDS AND SEAS. EXPECT
ELEVATED SEAS THROUGH THURSDAY AFTERNOON WITH SEAS PEAKING AROUND
12 FT EARLY THURSDAY MORNING. WINDS WILL REMAIN NEAR SMALL CRAFT
ADVISORY INTO FRIDAY MORNING...BUT WILL WEAKEN BRIEFLY ON THURSDAY
MORNING.

STRONGER WEATHER SYSTEM WILL MOVE THROUGH ON FRIDAY. GALES ARE
VERY POSSIBLE ON FRIDAY AHEAD OF FRONTAL PASSAGE ACROSS OUR
WATERS. THURSDAY SEAS WILL HOVER AROUND 9 TO 10 FT BEFORE START TO
BUILD AGAIN EARLY FRIDAY. WAVE HEIGHTS WILL REACH THE MIDDLE TEENS
BY MID-DAY FRIDAY AND COULD EVEN GET INTO THE UPPER TEENS ACROSS
THE SOUTHERN WATERS WITH GALE FORCE WINDS POSSIBLE IN THIS AREA.
WINDS AND SEAS WILL SUBSIDE SATURDAY TO 10 TO 11 FT...AND SEAS
LOOK TO REMAIN ABOVE 10 FT THROUGH THE WEEKEND.

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING RAIN ADVISORY UNTIL 4 AM PST THURSDAY FOR CENTRAL
     COLUMBIA RIVER GORGE-UPPER HOOD RIVER VALLEY-WESTERN
     COLUMBIA RIVER GORGE.

WA...FREEZING RAIN ADVISORY UNTIL 4 AM PST THURSDAY FOR CENTRAL
     COLUMBIA RIVER GORGE-WESTERN COLUMBIA RIVER GORGE.

PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 7 AM PST THURSDAY FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR
     OUT 60 NM.

     SMALL CRAFT ADVISORY FOR WINDS FROM 10 AM THURSDAY TO 4 AM PST
     FRIDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR

     OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 3 PM PST THURSDAY
     FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT
     60 NM.

     SMALL CRAFT ADVISORY FOR WINDS UNTIL 2 AM PST THURSDAY FOR
     COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 1 PM TO
     6 PM PST THURSDAY.

&&


$$

INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND

THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.




000
FXUS66 KPQR 200542
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
942 PM PST WED NOV 19 2014

.SYNOPSIS...RAIN WILL PUSH TO THE NORTHEAST ACROSS THE REGION TONIGHT
WITH FREEZING RAIN FOR THE COLUMBIA RIVER GORGE  AND HOOD RIVER. RAIN
SHOWERS WILL CONTINUE THURSDAY MORNING...EASING IN THE AFTERNOON AND
EVENING. A WELL ORGANIZED MOIST FRONT WILL BRING HEAVIER RAIN AND
GUSTY WIND FRIDAY NIGHT AND SATURDAY WITH RAIN AND MOUNTAIN SNOW
SHOWERS CONTINUING THROUGH THE WEEKEND. SNOW LEVELS WILL LIKELY LOWER
BELOW THE CASCADE PASSES SATURDAY.

&&

.UPDATE...SATELLITE AND RADAR IMAGERY SHOWS A FRONT CURRENTLY DRAPED
ACROSS NW OREGON FROM TILLAMOOK TO OAKRIDGE. THE FRONT AND ASSOCIATED
RAIN IS MOVING TO THE NW. AS OF 8 PM...THE LEADING EDGE OF THE RAIN
IS JUST REACHING ASTORIA...THE PORTLAND METRO AREA AND GOVERNMENT
CAMP. THE REAR EDGE OF THE RAIN IS ACROSS LINCOLN
CITY...CORVALLIS...AND SANTIAM JUNCTION. RAINFALL SO FAR HAS BEEN
HEAVIEST FOR THE CENTRAL OREGON COAST RANGE WHERE A QUARTER OF AN
INCH OF RAIN FELL...IN THE HILLS WEST OF EUGENE. OTHERWISE RAIN HAS
BEEN BETWEEN 0.05 AND 0.15 INCH.

SURFACE OBSERVATIONS AND WEB CAMS SUGGEST THAT THE SNOW LEVEL IS WELL
ABOVE THE CASCADE PASSES. TEMPERATURES IN THE NORTHER OREGON AND
SOUTH WASHINGTON CASCADES HAVE DROPPED SINCE SUNSET WITH MANY
LOCATIONS...ESPECIALLY IN THE LOWER ELEVATIONS ARE STILL BELOW OR
NEAR FREEZING. THE RAIN FRONT HAS WARMED TEMPERATURES WHERE IT PASSED
THIS AFTERNOON...BUT THE WARMING WILL BE LESS QUICK NOW THAT IT IS
NIGHT TIME. THEREFORE...EXPECT SOME AREAS OF FREEZING RAIN IN THE
EXTREME NORTHERN OREGON CASCADES AND THE SW WASHINGTON CASCADES FOR
THE LOWER ELEVATIONS BEFORE TURNING TO ALL RAIN.

THE EAST WINDS ARE FINALLY STARTING TO EASE...WITH THE TROUTDALE TO
DALLES SURFACE PRESSURE GRADIENT DROPPED BELOW 10 MB EARLIER THIS
EVENING. GUSTY EAST WINDS WILL GRADUALLY DECREASE AND THE GUSTS
SHOULD BE BELOW 30 MPH THURSDAY MORNING. WITH THAT SAID...THE CENTRAL
COLUMBIA RIVER GORGE AND THE UPPER HOOD RIVER VALLEY ARE STILL VERY
COLD...WITH TEMPERATURES BELOW FREEZING. RADAR SHOWS THE RAIN IS JUST
ABOUT TO REACH THAT AREA AND EXPECT THE MAIN PRECIPITATION TYPE WILL
BE FREEZING RAIN. WILL CONTINUE THE FREEZING RAIN ADVISORY FOR
TONIGHT. TRAPPED COLD AIR USUALLY TAKES MORE TIME THAN THE MODELS OR
WE THINK TO WARM...ESPECIALLY WITH A DEEP LAYER OF COLD AIR...AND
THERE IS A CHANCE THAT THE ADVISORY WILL NEED TO BE EXTENDED INTO THE
AFTERNOON. HAVE DECIDED TO WAIT TO SEE HOW THE RAIN MODIFIES THE
TEMPERATURES BEFORE ALTERING THE END END TIME OF THE ADVISORY. TJ

...FROM PREVIOUS SHORT TERM DISCUSSION...EXPECT THE PRIMARY THREAT TO
BE OVER BY 12Z/4AM THURSDAY BUT DO EXPECT FURTHER VERY LIGHT
ACCUMULATIONS THROUGH A LARGE PART OF THE DAY ACROSS THE ENTIRE AREA
AS ANOTHER DEVELOPING SHORT WAVE WILL LARGELY SLIDE SOUTH OF OUR AREA
AND MAINLY INTO NORTHERN CALIFORNIA. THERE WILL BE AREAS OF
DEFORMATION OVER US TO PRODUCE MORE OF A HYBRID STRATIFORM/SHOWER
PRECIP SCENARIO. SNOW LEVELS WILL BEGIN RISING RAPIDLY BY EARLY
FRIDAY AS WARM FRONTAL RAIN UNDER MOIST ZONAL PACIFIC FLOW SPREADS
FROM WEST TO EAST. BY THEMSELVES...QPF AMOUNTS ARE FAIRLY MODEST BUT
DO APPROACH AN INCH ENDING SATURDAY EVENING FOR THE VALLEYS AND A
LITTLE OVER 2 INCHES FOR THE CASCADES AND COAST RANGE. SNOW LEVELS
STAY HIGH UNTIL THE COLD FRONT DOES CROSS OVERNIGHT FRIDAY NIGHT.
EXPECT TO SEE A FEW INCHES OF PASS LEVEL ACCUMULATION LATER FRIDAY
AND FRIDAY NIGHT JUST AHEAD OF THE FRONT BUT THE MOISTURE EASES AFTER
THE FRONT WITH SNOW LEVELS FALLING TO AROUND 3000 FEET. HAVE ISSUED A
SPECIAL WEATHER STATEMENT FOR THE EXPECTED SNOW THIS WEEKEND.

AS MENTIONED PREVIOUSLY...DONT YET HAVE MUCH FAITH IN MODELED GORGE
TEMPERATURES RISING ABOVE FREEZING UNTIL PERHAPS LATER FRIDAY NIGHT
OR SATURDAY MORNING WHEN THE SURFACE PRESSURE GRADIENT TRULY BECOMES
WESTERLY. EXPERIENCE SHOWS MODELS ATTEMPT TO WARM UP THE GORGE BY
MIXING FROM ABOVE BUT THE COLDER DENSER AIR FROM EAST OF THE
CASCADES COMMONLY UNDERCUTS THAT MIXED LAYER UNTIL A SOLID WESTERLY
WIND PUSHES THROUGH THE LOWEST TERRAIN. AS SUCH WILL BE KEEPING A
CLOSE EYE ON WHAT ACTUALLY OCCURS TONIGHT AND EARLY TOMORROW. IF THE
HUNCH IS CORRECT...THE INCOMING SYSTEM FRIDAY COULD PRESENT A
SIGNIFICANT THREAT FOR AN ICE STORM COVERING AT LEAST THE CENTRAL
GORGE AND HOOD RIVER VALLEY...IF NOT THE WESTERN GORGE AS WELL. THE
ONE FACTOR IN FAVOR OF THE WARMING IS WE ARE STILL ON THE DOWNWARD
GLIDE SLOPE HEADING INTO CALENDAR WINTER. DECIDED TO HOLD OFF AND
TOW THE MODEL LINE REGARDING IMPROVING TEMPERATURES FOR NOW BUT
EXPECT THAT IF CONDITIONS REMAIN SUB-FREEZING NEAR AND EAST OF HOOD
RIVER...FRIDAY NIGHT COULD BE FAIRLY ICY. /JBONK

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...SATURDAY NIGHT
THROUGH WEDNESDAY. THE MORE WESTERLY OR
ZONAL FLOW THAT SETS UP LATE IN THE SHORT TERM PERIOD CONTINUES INTO
THE LONG TERM PERIOD...WITH OCCASIONAL RAIN AS DISTURBANCES MOVE
THROUGH. SOME RIDGING DEVELOPS IN THE NORTHEAST PACIFIC EARLY NEXT
WEEK...THOUGH THE MODELS VARY ON HOW MUCH. THE NORMALLY MORE RELIABLE
ECMWF MODEL HAS FLATTER RIDGING WITH MORE OF A DIRTY RIDGE TYPE
PATTERN AND DOES BRING SOME PRECIPITATION INTO THE FORECAST AREA AT
TIMES...WHILE THE OPERATIONAL GFS MODEL SHOWS MORE AMPLITUDE
DEVELOPING AND POSSIBLY SOME DRYING. THE PARALLEL VERSION OF THE GFS
MODEL IS A BIT MORE LIKE THE ECMWF. HAVE KEPT OUR CURRENT TRENDS
WHICH ARE MORE LIKE THE ECMWF AND THE PARALLEL GFS MODEL...THOUGH
CONFIDENCE IN ANY DETAILS ARE NOT VERY HIGH AT THIS POINT. TOLLESON
&&

.AVIATION...THE WARM FRONT IS CURRENTLY MOVING THROUGH THE REGION
WITH RAIN EXTENDING ALONG A LINE FROM KTMK SOUTHWEST TOWARDS LINN
COUNTY. EXPECT MAINLY MVFR CONDITIONS WITH LOWER CIGS THROUGH
THURSDAY MORNING. VFR CONDITIONS EXPECTED LATE THURSDAY MORNING.
HOWEVER...THERE REMAINS A CHANCE FOR RAIN AND MVFR CIGS INTO
THURSDAY AFTERNOON. GUSTY EAST WINDS AT KTTD WILL PREVAIL THROUGH
AROUND 13Z THURSDAY. MVFR TO IFR CONDITIONS POSSIBLE LATE THURSDAY
NIGHT ACROSS PORTIONS OF THE SOUTH WILLAMETTE VALLEY.


KPDX AND APPROACHES...VFR CONDITIONS WILL PREVAIL INTO THURSDAY
MORNING. THERE IS AN INCREASING CHANCE FOR RAIN AFTER 12Z THURSDAY
WHICH MAY BRING PERIODS OF MVFR TO IFR CONDITIONS.

&&

.MARINE...A WEAK WARM FRONT MOVED ACROSS THE WATERS THIS EVENING
BRINGING WITH IT SMALL CRAFT ADVISORY WINDS AND SEAS. EXPECT
ELEVATED SEAS THROUGH THURSDAY AFTERNOON WITH SEAS PEAKING AROUND
12 FT EARLY THURSDAY MORNING. WINDS WILL REMAIN NEAR SMALL CRAFT
ADVISORY INTO FRIDAY MORNING...BUT WILL WEAKEN BRIEFLY ON THURSDAY
MORNING.

STRONGER WEATHER SYSTEM WILL MOVE THROUGH ON FRIDAY. GALES ARE
VERY POSSIBLE ON FRIDAY AHEAD OF FRONTAL PASSAGE ACROSS OUR
WATERS. THURSDAY SEAS WILL HOVER AROUND 9 TO 10 FT BEFORE START TO
BUILD AGAIN EARLY FRIDAY. WAVE HEIGHTS WILL REACH THE MIDDLE TEENS
BY MID-DAY FRIDAY AND COULD EVEN GET INTO THE UPPER TEENS ACROSS
THE SOUTHERN WATERS WITH GALE FORCE WINDS POSSIBLE IN THIS AREA.
WINDS AND SEAS WILL SUBSIDE SATURDAY TO 10 TO 11 FT...AND SEAS
LOOK TO REMAIN ABOVE 10 FT THROUGH THE WEEKEND.

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING RAIN ADVISORY UNTIL 4 AM PST THURSDAY FOR CENTRAL
     COLUMBIA RIVER GORGE-UPPER HOOD RIVER VALLEY-WESTERN
     COLUMBIA RIVER GORGE.

WA...FREEZING RAIN ADVISORY UNTIL 4 AM PST THURSDAY FOR CENTRAL
     COLUMBIA RIVER GORGE-WESTERN COLUMBIA RIVER GORGE.

PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 7 AM PST THURSDAY FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR
     OUT 60 NM.

     SMALL CRAFT ADVISORY FOR WINDS FROM 10 AM THURSDAY TO 4 AM PST
     FRIDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR

     OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 3 PM PST THURSDAY
     FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT
     60 NM.

     SMALL CRAFT ADVISORY FOR WINDS UNTIL 2 AM PST THURSDAY FOR
     COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 1 PM TO
     6 PM PST THURSDAY.

&&


$$

INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND

THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.




000
FXUS66 KPQR 200542
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
942 PM PST WED NOV 19 2014

.SYNOPSIS...RAIN WILL PUSH TO THE NORTHEAST ACROSS THE REGION TONIGHT
WITH FREEZING RAIN FOR THE COLUMBIA RIVER GORGE  AND HOOD RIVER. RAIN
SHOWERS WILL CONTINUE THURSDAY MORNING...EASING IN THE AFTERNOON AND
EVENING. A WELL ORGANIZED MOIST FRONT WILL BRING HEAVIER RAIN AND
GUSTY WIND FRIDAY NIGHT AND SATURDAY WITH RAIN AND MOUNTAIN SNOW
SHOWERS CONTINUING THROUGH THE WEEKEND. SNOW LEVELS WILL LIKELY LOWER
BELOW THE CASCADE PASSES SATURDAY.

&&

.UPDATE...SATELLITE AND RADAR IMAGERY SHOWS A FRONT CURRENTLY DRAPED
ACROSS NW OREGON FROM TILLAMOOK TO OAKRIDGE. THE FRONT AND ASSOCIATED
RAIN IS MOVING TO THE NW. AS OF 8 PM...THE LEADING EDGE OF THE RAIN
IS JUST REACHING ASTORIA...THE PORTLAND METRO AREA AND GOVERNMENT
CAMP. THE REAR EDGE OF THE RAIN IS ACROSS LINCOLN
CITY...CORVALLIS...AND SANTIAM JUNCTION. RAINFALL SO FAR HAS BEEN
HEAVIEST FOR THE CENTRAL OREGON COAST RANGE WHERE A QUARTER OF AN
INCH OF RAIN FELL...IN THE HILLS WEST OF EUGENE. OTHERWISE RAIN HAS
BEEN BETWEEN 0.05 AND 0.15 INCH.

SURFACE OBSERVATIONS AND WEB CAMS SUGGEST THAT THE SNOW LEVEL IS WELL
ABOVE THE CASCADE PASSES. TEMPERATURES IN THE NORTHER OREGON AND
SOUTH WASHINGTON CASCADES HAVE DROPPED SINCE SUNSET WITH MANY
LOCATIONS...ESPECIALLY IN THE LOWER ELEVATIONS ARE STILL BELOW OR
NEAR FREEZING. THE RAIN FRONT HAS WARMED TEMPERATURES WHERE IT PASSED
THIS AFTERNOON...BUT THE WARMING WILL BE LESS QUICK NOW THAT IT IS
NIGHT TIME. THEREFORE...EXPECT SOME AREAS OF FREEZING RAIN IN THE
EXTREME NORTHERN OREGON CASCADES AND THE SW WASHINGTON CASCADES FOR
THE LOWER ELEVATIONS BEFORE TURNING TO ALL RAIN.

THE EAST WINDS ARE FINALLY STARTING TO EASE...WITH THE TROUTDALE TO
DALLES SURFACE PRESSURE GRADIENT DROPPED BELOW 10 MB EARLIER THIS
EVENING. GUSTY EAST WINDS WILL GRADUALLY DECREASE AND THE GUSTS
SHOULD BE BELOW 30 MPH THURSDAY MORNING. WITH THAT SAID...THE CENTRAL
COLUMBIA RIVER GORGE AND THE UPPER HOOD RIVER VALLEY ARE STILL VERY
COLD...WITH TEMPERATURES BELOW FREEZING. RADAR SHOWS THE RAIN IS JUST
ABOUT TO REACH THAT AREA AND EXPECT THE MAIN PRECIPITATION TYPE WILL
BE FREEZING RAIN. WILL CONTINUE THE FREEZING RAIN ADVISORY FOR
TONIGHT. TRAPPED COLD AIR USUALLY TAKES MORE TIME THAN THE MODELS OR
WE THINK TO WARM...ESPECIALLY WITH A DEEP LAYER OF COLD AIR...AND
THERE IS A CHANCE THAT THE ADVISORY WILL NEED TO BE EXTENDED INTO THE
AFTERNOON. HAVE DECIDED TO WAIT TO SEE HOW THE RAIN MODIFIES THE
TEMPERATURES BEFORE ALTERING THE END END TIME OF THE ADVISORY. TJ

...FROM PREVIOUS SHORT TERM DISCUSSION...EXPECT THE PRIMARY THREAT TO
BE OVER BY 12Z/4AM THURSDAY BUT DO EXPECT FURTHER VERY LIGHT
ACCUMULATIONS THROUGH A LARGE PART OF THE DAY ACROSS THE ENTIRE AREA
AS ANOTHER DEVELOPING SHORT WAVE WILL LARGELY SLIDE SOUTH OF OUR AREA
AND MAINLY INTO NORTHERN CALIFORNIA. THERE WILL BE AREAS OF
DEFORMATION OVER US TO PRODUCE MORE OF A HYBRID STRATIFORM/SHOWER
PRECIP SCENARIO. SNOW LEVELS WILL BEGIN RISING RAPIDLY BY EARLY
FRIDAY AS WARM FRONTAL RAIN UNDER MOIST ZONAL PACIFIC FLOW SPREADS
FROM WEST TO EAST. BY THEMSELVES...QPF AMOUNTS ARE FAIRLY MODEST BUT
DO APPROACH AN INCH ENDING SATURDAY EVENING FOR THE VALLEYS AND A
LITTLE OVER 2 INCHES FOR THE CASCADES AND COAST RANGE. SNOW LEVELS
STAY HIGH UNTIL THE COLD FRONT DOES CROSS OVERNIGHT FRIDAY NIGHT.
EXPECT TO SEE A FEW INCHES OF PASS LEVEL ACCUMULATION LATER FRIDAY
AND FRIDAY NIGHT JUST AHEAD OF THE FRONT BUT THE MOISTURE EASES AFTER
THE FRONT WITH SNOW LEVELS FALLING TO AROUND 3000 FEET. HAVE ISSUED A
SPECIAL WEATHER STATEMENT FOR THE EXPECTED SNOW THIS WEEKEND.

AS MENTIONED PREVIOUSLY...DONT YET HAVE MUCH FAITH IN MODELED GORGE
TEMPERATURES RISING ABOVE FREEZING UNTIL PERHAPS LATER FRIDAY NIGHT
OR SATURDAY MORNING WHEN THE SURFACE PRESSURE GRADIENT TRULY BECOMES
WESTERLY. EXPERIENCE SHOWS MODELS ATTEMPT TO WARM UP THE GORGE BY
MIXING FROM ABOVE BUT THE COLDER DENSER AIR FROM EAST OF THE
CASCADES COMMONLY UNDERCUTS THAT MIXED LAYER UNTIL A SOLID WESTERLY
WIND PUSHES THROUGH THE LOWEST TERRAIN. AS SUCH WILL BE KEEPING A
CLOSE EYE ON WHAT ACTUALLY OCCURS TONIGHT AND EARLY TOMORROW. IF THE
HUNCH IS CORRECT...THE INCOMING SYSTEM FRIDAY COULD PRESENT A
SIGNIFICANT THREAT FOR AN ICE STORM COVERING AT LEAST THE CENTRAL
GORGE AND HOOD RIVER VALLEY...IF NOT THE WESTERN GORGE AS WELL. THE
ONE FACTOR IN FAVOR OF THE WARMING IS WE ARE STILL ON THE DOWNWARD
GLIDE SLOPE HEADING INTO CALENDAR WINTER. DECIDED TO HOLD OFF AND
TOW THE MODEL LINE REGARDING IMPROVING TEMPERATURES FOR NOW BUT
EXPECT THAT IF CONDITIONS REMAIN SUB-FREEZING NEAR AND EAST OF HOOD
RIVER...FRIDAY NIGHT COULD BE FAIRLY ICY. /JBONK

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...SATURDAY NIGHT
THROUGH WEDNESDAY. THE MORE WESTERLY OR
ZONAL FLOW THAT SETS UP LATE IN THE SHORT TERM PERIOD CONTINUES INTO
THE LONG TERM PERIOD...WITH OCCASIONAL RAIN AS DISTURBANCES MOVE
THROUGH. SOME RIDGING DEVELOPS IN THE NORTHEAST PACIFIC EARLY NEXT
WEEK...THOUGH THE MODELS VARY ON HOW MUCH. THE NORMALLY MORE RELIABLE
ECMWF MODEL HAS FLATTER RIDGING WITH MORE OF A DIRTY RIDGE TYPE
PATTERN AND DOES BRING SOME PRECIPITATION INTO THE FORECAST AREA AT
TIMES...WHILE THE OPERATIONAL GFS MODEL SHOWS MORE AMPLITUDE
DEVELOPING AND POSSIBLY SOME DRYING. THE PARALLEL VERSION OF THE GFS
MODEL IS A BIT MORE LIKE THE ECMWF. HAVE KEPT OUR CURRENT TRENDS
WHICH ARE MORE LIKE THE ECMWF AND THE PARALLEL GFS MODEL...THOUGH
CONFIDENCE IN ANY DETAILS ARE NOT VERY HIGH AT THIS POINT. TOLLESON
&&

.AVIATION...THE WARM FRONT IS CURRENTLY MOVING THROUGH THE REGION
WITH RAIN EXTENDING ALONG A LINE FROM KTMK SOUTHWEST TOWARDS LINN
COUNTY. EXPECT MAINLY MVFR CONDITIONS WITH LOWER CIGS THROUGH
THURSDAY MORNING. VFR CONDITIONS EXPECTED LATE THURSDAY MORNING.
HOWEVER...THERE REMAINS A CHANCE FOR RAIN AND MVFR CIGS INTO
THURSDAY AFTERNOON. GUSTY EAST WINDS AT KTTD WILL PREVAIL THROUGH
AROUND 13Z THURSDAY. MVFR TO IFR CONDITIONS POSSIBLE LATE THURSDAY
NIGHT ACROSS PORTIONS OF THE SOUTH WILLAMETTE VALLEY.


KPDX AND APPROACHES...VFR CONDITIONS WILL PREVAIL INTO THURSDAY
MORNING. THERE IS AN INCREASING CHANCE FOR RAIN AFTER 12Z THURSDAY
WHICH MAY BRING PERIODS OF MVFR TO IFR CONDITIONS.

&&

.MARINE...A WEAK WARM FRONT MOVED ACROSS THE WATERS THIS EVENING
BRINGING WITH IT SMALL CRAFT ADVISORY WINDS AND SEAS. EXPECT
ELEVATED SEAS THROUGH THURSDAY AFTERNOON WITH SEAS PEAKING AROUND
12 FT EARLY THURSDAY MORNING. WINDS WILL REMAIN NEAR SMALL CRAFT
ADVISORY INTO FRIDAY MORNING...BUT WILL WEAKEN BRIEFLY ON THURSDAY
MORNING.

STRONGER WEATHER SYSTEM WILL MOVE THROUGH ON FRIDAY. GALES ARE
VERY POSSIBLE ON FRIDAY AHEAD OF FRONTAL PASSAGE ACROSS OUR
WATERS. THURSDAY SEAS WILL HOVER AROUND 9 TO 10 FT BEFORE START TO
BUILD AGAIN EARLY FRIDAY. WAVE HEIGHTS WILL REACH THE MIDDLE TEENS
BY MID-DAY FRIDAY AND COULD EVEN GET INTO THE UPPER TEENS ACROSS
THE SOUTHERN WATERS WITH GALE FORCE WINDS POSSIBLE IN THIS AREA.
WINDS AND SEAS WILL SUBSIDE SATURDAY TO 10 TO 11 FT...AND SEAS
LOOK TO REMAIN ABOVE 10 FT THROUGH THE WEEKEND.

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING RAIN ADVISORY UNTIL 4 AM PST THURSDAY FOR CENTRAL
     COLUMBIA RIVER GORGE-UPPER HOOD RIVER VALLEY-WESTERN
     COLUMBIA RIVER GORGE.

WA...FREEZING RAIN ADVISORY UNTIL 4 AM PST THURSDAY FOR CENTRAL
     COLUMBIA RIVER GORGE-WESTERN COLUMBIA RIVER GORGE.

PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 7 AM PST THURSDAY FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR
     OUT 60 NM.

     SMALL CRAFT ADVISORY FOR WINDS FROM 10 AM THURSDAY TO 4 AM PST
     FRIDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR

     OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 3 PM PST THURSDAY
     FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT
     60 NM.

     SMALL CRAFT ADVISORY FOR WINDS UNTIL 2 AM PST THURSDAY FOR
     COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 1 PM TO
     6 PM PST THURSDAY.

&&


$$

INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND

THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.




000
FXUS66 KOTX 200503
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
903 PM PST WED NOV 19 2014

.SYNOPSIS...
A weak weather system will arrive late tonight into Thursday with
the potential for a light wintry mix of rain...snow...and freezing
rain. A stronger, wetter and windier weather system will arrive
Friday persisting into the weekend with heavy snow amounts
possible over the mountains. The weather pattern will remain
active through the middle of next week.


&&

.DISCUSSION...

...SLICK TRAVEL EXPECTED OVER SOUTHEASTERN WA ALONG HIGHWAY 26 and
HIGHWAY 12 DUE TO FREEZING RAIN AND SLEET EARLY THURSDAY MORNING...

...A MIX OF LIGHT SNOW AND SLEET POSSIBLE DURING THE MORNING
COMMUTE IN EASTERN WA AND NORTHERN IDAHO...

Evening update: A tricky yet low precipitation event will pass
through the region early Thursday morning and depart in the
afternoon. At this time, it looks like the best chance for
freezing rain mixing with sleet will be over southeastern WA from
northern Garfield County into southwestern Whitman...and southern
Adams County. These areas are currently in the mid 20s and model
profiles are most favorable for a these precipitation types.
Amounts are the unknown factor with the last few runs of the HRRR
simulated reflectivity trending toward the drier NAM. This will
mean the potential ranging from a trace to few hundreths of
liquid. Slick conditions a strong possibility for the Thursday
morning commute but anticipated ice accumulations remains in low
confidence. Nonetheless, Highway 26 and Highway 12 look to carry
the highest threat for icy roads from freezing rain/sleet.

The further north you travel from Pullman to Spokane-CDA-Kellogg-
St Maries. The chance for precipitation to remain as snow becomes
much better. My guess is areas of Benewah/Latah/Kootenai/Shoshone
County will stand the best chance for up to an inch of snow with
less than a half an inch into Spokane, NE WA, and far northern ID
Panhandle. One reason is the lack of QPF but a second will be low
snow ratios. KOTX sounding indicated the top of the inversion
layer around +3C. While this will wetbulb below freezing to
support snow, snowflakes will undergo some melting/rounding and
just having a hard time supporting snow ratios above 10:1. If
precipitation intensity is higher than expected, this could yield
slightly higher amounts. Another factor is temperatures are
currently above freezing between Pullman and Lewiston. Local
downsloping this afternoon warmed temperatures into the 40`s.
Dewpoints remain dry enough to support wetbulbing near to below
freezing but not by much and if precip intensity remains light,
this may never occur. On the other end of the spectrum, it is
still only 9PM and precipitation will not arrive until 5AM so
there is still time to cool but increasing clouds does not favor
any big drops.

Further west, a passing trace to hundreth is expected as the
frontal occlusion lifts north. Models do not show much in the way
of QPF from Wenatchee to Omak but dynamics are a bit stronger on
this side of the CWA so will leave some chance for snow with
amounts generally between a trace and tenth. Up to an inch will be
possible in the mountains and across the Cascade Passes.

&&

.AVIATION...
00Z TAFS: Ridge of high pressure keeps VFR conditions prevailing
for most aviation sites until about 09-12Z. A weak warm front
moves through the area spreading a wintry mix of light snow with
some freezing rain possible generally south of I-90 starting as
early as 9Z near KEAT and about 12Z near KGEG vicinity.
Accumulations, if any, are expected to be very light. After the
front moves off Thursday morning...a moist boundary layer with
weak upslope flow will maintain the threat of MVFR ceilings over
the eastern TAF sites. /MJF



&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        23  34  31  38  34  42 /  10  70  20  40  90  40
Coeur d`Alene  23  34  32  40  34  41 /  10  70  30  50  90  70
Pullman        31  39  29  42  35  42 /  20  80  20  20  90  70
Lewiston       33  40  31  44  40  47 /  30  80  10  10  80  50
Colville       22  34  26  38  36  42 /   0  30  30  70 100  40
Sandpoint      21  34  30  40  34  41 /   0  50  50  70 100  60
Kellogg        25  34  31  38  34  38 /  10  80  40  50  90  90
Moses Lake     24  35  21  37  31  48 /  40  20  10  70 100  20
Wenatchee      29  39  28  35  33  46 /  50  20  10  80 100  20
Omak           24  36  27  36  31  43 /  10  20  10  80 100  20

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Air Stagnation Advisory until Noon PST Friday for Central
     Panhandle Mountains-Coeur d`Alene Area-Idaho Palouse-
     Northern Panhandle.

     Winter Storm Watch from Friday afternoon through Saturday
     afternoon for Central Panhandle Mountains-Northern
     Panhandle.

WA...Air Stagnation Advisory until Noon PST Friday for East Slopes
     Northern Cascades-Lower Garfield and Asotin Counties-Moses
     Lake Area-Northeast Mountains-Okanogan Highlands-Spokane
     Area-Upper Columbia Basin-Washington Palouse-Waterville
     Plateau-Wenatchee Area.

     Winter Storm Watch from Friday afternoon through Saturday
     afternoon for Northeast Mountains-Okanogan Highlands.

     Winter Storm Watch from Friday morning through late Friday night
     for East Slopes Northern Cascades.

&&

$$




000
FXUS66 KOTX 200503
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
903 PM PST WED NOV 19 2014

.SYNOPSIS...
A weak weather system will arrive late tonight into Thursday with
the potential for a light wintry mix of rain...snow...and freezing
rain. A stronger, wetter and windier weather system will arrive
Friday persisting into the weekend with heavy snow amounts
possible over the mountains. The weather pattern will remain
active through the middle of next week.


&&

.DISCUSSION...

...SLICK TRAVEL EXPECTED OVER SOUTHEASTERN WA ALONG HIGHWAY 26 and
HIGHWAY 12 DUE TO FREEZING RAIN AND SLEET EARLY THURSDAY MORNING...

...A MIX OF LIGHT SNOW AND SLEET POSSIBLE DURING THE MORNING
COMMUTE IN EASTERN WA AND NORTHERN IDAHO...

Evening update: A tricky yet low precipitation event will pass
through the region early Thursday morning and depart in the
afternoon. At this time, it looks like the best chance for
freezing rain mixing with sleet will be over southeastern WA from
northern Garfield County into southwestern Whitman...and southern
Adams County. These areas are currently in the mid 20s and model
profiles are most favorable for a these precipitation types.
Amounts are the unknown factor with the last few runs of the HRRR
simulated reflectivity trending toward the drier NAM. This will
mean the potential ranging from a trace to few hundreths of
liquid. Slick conditions a strong possibility for the Thursday
morning commute but anticipated ice accumulations remains in low
confidence. Nonetheless, Highway 26 and Highway 12 look to carry
the highest threat for icy roads from freezing rain/sleet.

The further north you travel from Pullman to Spokane-CDA-Kellogg-
St Maries. The chance for precipitation to remain as snow becomes
much better. My guess is areas of Benewah/Latah/Kootenai/Shoshone
County will stand the best chance for up to an inch of snow with
less than a half an inch into Spokane, NE WA, and far northern ID
Panhandle. One reason is the lack of QPF but a second will be low
snow ratios. KOTX sounding indicated the top of the inversion
layer around +3C. While this will wetbulb below freezing to
support snow, snowflakes will undergo some melting/rounding and
just having a hard time supporting snow ratios above 10:1. If
precipitation intensity is higher than expected, this could yield
slightly higher amounts. Another factor is temperatures are
currently above freezing between Pullman and Lewiston. Local
downsloping this afternoon warmed temperatures into the 40`s.
Dewpoints remain dry enough to support wetbulbing near to below
freezing but not by much and if precip intensity remains light,
this may never occur. On the other end of the spectrum, it is
still only 9PM and precipitation will not arrive until 5AM so
there is still time to cool but increasing clouds does not favor
any big drops.

Further west, a passing trace to hundreth is expected as the
frontal occlusion lifts north. Models do not show much in the way
of QPF from Wenatchee to Omak but dynamics are a bit stronger on
this side of the CWA so will leave some chance for snow with
amounts generally between a trace and tenth. Up to an inch will be
possible in the mountains and across the Cascade Passes.

&&

.AVIATION...
00Z TAFS: Ridge of high pressure keeps VFR conditions prevailing
for most aviation sites until about 09-12Z. A weak warm front
moves through the area spreading a wintry mix of light snow with
some freezing rain possible generally south of I-90 starting as
early as 9Z near KEAT and about 12Z near KGEG vicinity.
Accumulations, if any, are expected to be very light. After the
front moves off Thursday morning...a moist boundary layer with
weak upslope flow will maintain the threat of MVFR ceilings over
the eastern TAF sites. /MJF



&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        23  34  31  38  34  42 /  10  70  20  40  90  40
Coeur d`Alene  23  34  32  40  34  41 /  10  70  30  50  90  70
Pullman        31  39  29  42  35  42 /  20  80  20  20  90  70
Lewiston       33  40  31  44  40  47 /  30  80  10  10  80  50
Colville       22  34  26  38  36  42 /   0  30  30  70 100  40
Sandpoint      21  34  30  40  34  41 /   0  50  50  70 100  60
Kellogg        25  34  31  38  34  38 /  10  80  40  50  90  90
Moses Lake     24  35  21  37  31  48 /  40  20  10  70 100  20
Wenatchee      29  39  28  35  33  46 /  50  20  10  80 100  20
Omak           24  36  27  36  31  43 /  10  20  10  80 100  20

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Air Stagnation Advisory until Noon PST Friday for Central
     Panhandle Mountains-Coeur d`Alene Area-Idaho Palouse-
     Northern Panhandle.

     Winter Storm Watch from Friday afternoon through Saturday
     afternoon for Central Panhandle Mountains-Northern
     Panhandle.

WA...Air Stagnation Advisory until Noon PST Friday for East Slopes
     Northern Cascades-Lower Garfield and Asotin Counties-Moses
     Lake Area-Northeast Mountains-Okanogan Highlands-Spokane
     Area-Upper Columbia Basin-Washington Palouse-Waterville
     Plateau-Wenatchee Area.

     Winter Storm Watch from Friday afternoon through Saturday
     afternoon for Northeast Mountains-Okanogan Highlands.

     Winter Storm Watch from Friday morning through late Friday night
     for East Slopes Northern Cascades.

&&

$$




000
FXUS66 KOTX 200503
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
903 PM PST WED NOV 19 2014

.SYNOPSIS...
A weak weather system will arrive late tonight into Thursday with
the potential for a light wintry mix of rain...snow...and freezing
rain. A stronger, wetter and windier weather system will arrive
Friday persisting into the weekend with heavy snow amounts
possible over the mountains. The weather pattern will remain
active through the middle of next week.


&&

.DISCUSSION...

...SLICK TRAVEL EXPECTED OVER SOUTHEASTERN WA ALONG HIGHWAY 26 and
HIGHWAY 12 DUE TO FREEZING RAIN AND SLEET EARLY THURSDAY MORNING...

...A MIX OF LIGHT SNOW AND SLEET POSSIBLE DURING THE MORNING
COMMUTE IN EASTERN WA AND NORTHERN IDAHO...

Evening update: A tricky yet low precipitation event will pass
through the region early Thursday morning and depart in the
afternoon. At this time, it looks like the best chance for
freezing rain mixing with sleet will be over southeastern WA from
northern Garfield County into southwestern Whitman...and southern
Adams County. These areas are currently in the mid 20s and model
profiles are most favorable for a these precipitation types.
Amounts are the unknown factor with the last few runs of the HRRR
simulated reflectivity trending toward the drier NAM. This will
mean the potential ranging from a trace to few hundreths of
liquid. Slick conditions a strong possibility for the Thursday
morning commute but anticipated ice accumulations remains in low
confidence. Nonetheless, Highway 26 and Highway 12 look to carry
the highest threat for icy roads from freezing rain/sleet.

The further north you travel from Pullman to Spokane-CDA-Kellogg-
St Maries. The chance for precipitation to remain as snow becomes
much better. My guess is areas of Benewah/Latah/Kootenai/Shoshone
County will stand the best chance for up to an inch of snow with
less than a half an inch into Spokane, NE WA, and far northern ID
Panhandle. One reason is the lack of QPF but a second will be low
snow ratios. KOTX sounding indicated the top of the inversion
layer around +3C. While this will wetbulb below freezing to
support snow, snowflakes will undergo some melting/rounding and
just having a hard time supporting snow ratios above 10:1. If
precipitation intensity is higher than expected, this could yield
slightly higher amounts. Another factor is temperatures are
currently above freezing between Pullman and Lewiston. Local
downsloping this afternoon warmed temperatures into the 40`s.
Dewpoints remain dry enough to support wetbulbing near to below
freezing but not by much and if precip intensity remains light,
this may never occur. On the other end of the spectrum, it is
still only 9PM and precipitation will not arrive until 5AM so
there is still time to cool but increasing clouds does not favor
any big drops.

Further west, a passing trace to hundreth is expected as the
frontal occlusion lifts north. Models do not show much in the way
of QPF from Wenatchee to Omak but dynamics are a bit stronger on
this side of the CWA so will leave some chance for snow with
amounts generally between a trace and tenth. Up to an inch will be
possible in the mountains and across the Cascade Passes.

&&

.AVIATION...
00Z TAFS: Ridge of high pressure keeps VFR conditions prevailing
for most aviation sites until about 09-12Z. A weak warm front
moves through the area spreading a wintry mix of light snow with
some freezing rain possible generally south of I-90 starting as
early as 9Z near KEAT and about 12Z near KGEG vicinity.
Accumulations, if any, are expected to be very light. After the
front moves off Thursday morning...a moist boundary layer with
weak upslope flow will maintain the threat of MVFR ceilings over
the eastern TAF sites. /MJF



&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        23  34  31  38  34  42 /  10  70  20  40  90  40
Coeur d`Alene  23  34  32  40  34  41 /  10  70  30  50  90  70
Pullman        31  39  29  42  35  42 /  20  80  20  20  90  70
Lewiston       33  40  31  44  40  47 /  30  80  10  10  80  50
Colville       22  34  26  38  36  42 /   0  30  30  70 100  40
Sandpoint      21  34  30  40  34  41 /   0  50  50  70 100  60
Kellogg        25  34  31  38  34  38 /  10  80  40  50  90  90
Moses Lake     24  35  21  37  31  48 /  40  20  10  70 100  20
Wenatchee      29  39  28  35  33  46 /  50  20  10  80 100  20
Omak           24  36  27  36  31  43 /  10  20  10  80 100  20

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Air Stagnation Advisory until Noon PST Friday for Central
     Panhandle Mountains-Coeur d`Alene Area-Idaho Palouse-
     Northern Panhandle.

     Winter Storm Watch from Friday afternoon through Saturday
     afternoon for Central Panhandle Mountains-Northern
     Panhandle.

WA...Air Stagnation Advisory until Noon PST Friday for East Slopes
     Northern Cascades-Lower Garfield and Asotin Counties-Moses
     Lake Area-Northeast Mountains-Okanogan Highlands-Spokane
     Area-Upper Columbia Basin-Washington Palouse-Waterville
     Plateau-Wenatchee Area.

     Winter Storm Watch from Friday afternoon through Saturday
     afternoon for Northeast Mountains-Okanogan Highlands.

     Winter Storm Watch from Friday morning through late Friday night
     for East Slopes Northern Cascades.

&&

$$




000
FXUS66 KOTX 200503
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
903 PM PST WED NOV 19 2014

.SYNOPSIS...
A weak weather system will arrive late tonight into Thursday with
the potential for a light wintry mix of rain...snow...and freezing
rain. A stronger, wetter and windier weather system will arrive
Friday persisting into the weekend with heavy snow amounts
possible over the mountains. The weather pattern will remain
active through the middle of next week.


&&

.DISCUSSION...

...SLICK TRAVEL EXPECTED OVER SOUTHEASTERN WA ALONG HIGHWAY 26 and
HIGHWAY 12 DUE TO FREEZING RAIN AND SLEET EARLY THURSDAY MORNING...

...A MIX OF LIGHT SNOW AND SLEET POSSIBLE DURING THE MORNING
COMMUTE IN EASTERN WA AND NORTHERN IDAHO...

Evening update: A tricky yet low precipitation event will pass
through the region early Thursday morning and depart in the
afternoon. At this time, it looks like the best chance for
freezing rain mixing with sleet will be over southeastern WA from
northern Garfield County into southwestern Whitman...and southern
Adams County. These areas are currently in the mid 20s and model
profiles are most favorable for a these precipitation types.
Amounts are the unknown factor with the last few runs of the HRRR
simulated reflectivity trending toward the drier NAM. This will
mean the potential ranging from a trace to few hundreths of
liquid. Slick conditions a strong possibility for the Thursday
morning commute but anticipated ice accumulations remains in low
confidence. Nonetheless, Highway 26 and Highway 12 look to carry
the highest threat for icy roads from freezing rain/sleet.

The further north you travel from Pullman to Spokane-CDA-Kellogg-
St Maries. The chance for precipitation to remain as snow becomes
much better. My guess is areas of Benewah/Latah/Kootenai/Shoshone
County will stand the best chance for up to an inch of snow with
less than a half an inch into Spokane, NE WA, and far northern ID
Panhandle. One reason is the lack of QPF but a second will be low
snow ratios. KOTX sounding indicated the top of the inversion
layer around +3C. While this will wetbulb below freezing to
support snow, snowflakes will undergo some melting/rounding and
just having a hard time supporting snow ratios above 10:1. If
precipitation intensity is higher than expected, this could yield
slightly higher amounts. Another factor is temperatures are
currently above freezing between Pullman and Lewiston. Local
downsloping this afternoon warmed temperatures into the 40`s.
Dewpoints remain dry enough to support wetbulbing near to below
freezing but not by much and if precip intensity remains light,
this may never occur. On the other end of the spectrum, it is
still only 9PM and precipitation will not arrive until 5AM so
there is still time to cool but increasing clouds does not favor
any big drops.

Further west, a passing trace to hundreth is expected as the
frontal occlusion lifts north. Models do not show much in the way
of QPF from Wenatchee to Omak but dynamics are a bit stronger on
this side of the CWA so will leave some chance for snow with
amounts generally between a trace and tenth. Up to an inch will be
possible in the mountains and across the Cascade Passes.

&&

.AVIATION...
00Z TAFS: Ridge of high pressure keeps VFR conditions prevailing
for most aviation sites until about 09-12Z. A weak warm front
moves through the area spreading a wintry mix of light snow with
some freezing rain possible generally south of I-90 starting as
early as 9Z near KEAT and about 12Z near KGEG vicinity.
Accumulations, if any, are expected to be very light. After the
front moves off Thursday morning...a moist boundary layer with
weak upslope flow will maintain the threat of MVFR ceilings over
the eastern TAF sites. /MJF



&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        23  34  31  38  34  42 /  10  70  20  40  90  40
Coeur d`Alene  23  34  32  40  34  41 /  10  70  30  50  90  70
Pullman        31  39  29  42  35  42 /  20  80  20  20  90  70
Lewiston       33  40  31  44  40  47 /  30  80  10  10  80  50
Colville       22  34  26  38  36  42 /   0  30  30  70 100  40
Sandpoint      21  34  30  40  34  41 /   0  50  50  70 100  60
Kellogg        25  34  31  38  34  38 /  10  80  40  50  90  90
Moses Lake     24  35  21  37  31  48 /  40  20  10  70 100  20
Wenatchee      29  39  28  35  33  46 /  50  20  10  80 100  20
Omak           24  36  27  36  31  43 /  10  20  10  80 100  20

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Air Stagnation Advisory until Noon PST Friday for Central
     Panhandle Mountains-Coeur d`Alene Area-Idaho Palouse-
     Northern Panhandle.

     Winter Storm Watch from Friday afternoon through Saturday
     afternoon for Central Panhandle Mountains-Northern
     Panhandle.

WA...Air Stagnation Advisory until Noon PST Friday for East Slopes
     Northern Cascades-Lower Garfield and Asotin Counties-Moses
     Lake Area-Northeast Mountains-Okanogan Highlands-Spokane
     Area-Upper Columbia Basin-Washington Palouse-Waterville
     Plateau-Wenatchee Area.

     Winter Storm Watch from Friday afternoon through Saturday
     afternoon for Northeast Mountains-Okanogan Highlands.

     Winter Storm Watch from Friday morning through late Friday night
     for East Slopes Northern Cascades.

&&

$$




000
FXUS66 KSEW 200501
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
900 PM PST WED NOV 19 2014

.SYNOPSIS...A FRONT WILL BRING SOME RAIN TONIGHT. ANOTHER STRONGER
FRONT WILL IMPACT THE AREA ON FRIDAY AND FRIDAY NIGHT...BRINGING
RAIN...WIND...AND SNOW TO THE MOUNTAINS. ADDITIONAL WEATHER SYSTEMS
WILL ARRIVE EVERY DAY OR TWO THROUGH THE MIDDLE OF NEXT WEEK.

&&

.SHORT TERM...A COLD FRONT WILL LIFT NORTH THROUGH WESTERN WA
TONIGHT BRINGING A LITTLE RAIN TO THE AREA. THE FRONT IS NOW
REACHING KHQM...BUT THERE ARE A FEW LIGHT SHOWERS ALSO AFFECTING THE
NORTH INTERIOR. EAST WINDS WILL KEEP TEMPS BELOW FREEZING IN THE
PASSES AND MAY SEE FREEZING RAIN AT SNOQUALMIE AND STEVENS PASS.
TEMPS WILL REMAIN ABOVE FREEZING ACROSS THE LOWLANDS TONIGHT. THIS
FRONT WILL EXIT NORTH THURSDAY MORNING WITH RAIN TAPERING DOWN. A
WEAK UPPER TROUGH WILL SHIFT INLAND FOR JUST ISOLATED TO SCATTERED
SHOWERS ACROSS THE REGION DURING THE AFTERNOON.

A STRONGER PAC SYSTEM WILL BRING WET AND WINDY WEATHER TO WESTERN WA
ON FRI. SO FAR MODELS ARE PRETTY CONSISTENT WITH THIS SYSTEM. RAIN
WILL BEGIN ON THE COAST FRI MORNING...WITH RAIN SPREADING INLAND BY
THE AFTERNOON. IT WILL BE WINDY ALONG THE COAST AND NORTH INTERIOR.
RAIN WILL CONTINUE THROUGH THE EVENING AS THE COLD FRONT MOVES
INLAND. THE SNOW LEVEL WILL LOWER TO AROUND 4000 FT FRIDAY NIGHT AND
STEVENS PASS MAY SEE A FEW INCHES OF SNOW...WITH WINTER WEATHER
ADVISORY AMOUNTS POSSIBLE AT MOUNT BAKER. THE AIR MASS WILL REMAIN
COOL AND UNSETTLED THROUGH EARLY SAT MORNING AS THE UPPER TROUGH
PASSES THROUGH.

ONSHORE FLOW WILL CONTINUE ON SAT FOR ADDITIONAL SHOWERS ACROSS THE
REGION. MAY ALSO SEE A PUGET SOUND CONVERGENCE ZONE DEVELOP IN
SNOHOMISH/KING COUNTIES...WITH MORE SNOW EXPECTED IN THE MOUNTAINS.
33

.LONG TERM...PREVIOUS DISCUSSION...A COUPLE MORE SHORTWAVE TROUGHS
WILL LIKELY IMPACT THE AREA ON SUNDAY AND MONDAY...KEEPING BREEZY
CONDITIONS AND PRECIPITATION IN THE FORECAST. ON TUESDAY...MODELS
ARE BEGINNING TO AGREE THAT A PLUME OF MOISTURE CARRIED BY THE JET
STREAM WILL IMPACT THE NORTHWEST...AS PREDICTED BY THE ECMWF
YESTERDAY. HOWEVER...A LOT OF UNCERTAINTY EXISTS AS TO WHERE THIS
MOISTURE WILL COME ASHORE...THE ECMWF HAS IT HITTING OREGON WHEREAS
THE GFS HAS IT IMPACTING NORTHWEST WASHINGTON AND SOUTHWEST BC.
THERE IS ALSO UNCERTAINTY AS TO WHETHER IT WILL BE ACCOMPANIED BY A
SURFACE LOW PRESSURE SYSTEM.

MODELS DISAGREE ON ABOUT JUST ABOUT EVERYTHING WEDNESDAY AND
BEYOND...SO THE FORECAST IS VERY UNCERTAIN AT THIS POINT. JSMITH

&&

.HYDROLOGY...RIVER FLOODING IS NOT EXPECTED IN THE NEXT 7 DAYS.

&&

.AVIATION...A COLD FRONT OVER THE OREGON OFFSHORE WATERS WILL MOVE
NORTHEAST ACROSS WESTERN WASHINGTON TONIGHT. CEILINGS BKN060-100
AHEAD OF THE FRONT WILL LOWER TO MVFR LEVELS WITH AND BEHIND THE
FRONT. LOCAL IFR CIGS ARE POSSIBLE AFTER 12Z. WEAK POST-FRONTAL
WESTERLY FLOW ALOFT WILL PREVAIL ON THURSDAY. A MOIST AIR MASS WILL
KEEP CEILINGS MAINLY IN THE 2000-5000 FOOT RANGE.

KSEA...GOOD VFR CONDITIONS WITH CEILINGS ABOVE BKN080-100 WILL
CONTINUE THROUGH ABOUT 08Z TONIGHT. RAIN FROM THE APPROACHING FRONT
SHOULD REACH THE TERMINAL AROUND 08Z WITH MVFR CEILINGS AFTER 09Z.
WINDS SOUTHEAST 6-10 KT. CHB

&&

.MARINE...A COLD FRONT APPROACHING FROM THE SOUTHWEST WILL MOVE
ACROSS WESTERN WASHINGTON LATE TONIGHT. MODERATE SOUTHEAST FLOW WILL
BRING SMALL CRAFT ADVISORY WINDS TO MOST WATERS. POST FRONT ADVISORY
LEVEL WINDS WILL CONTINUE THROUGH THURSDAY MORNING.

MODELS REMAIN CONSISTENT IN BRINGING A STRONGER FRONTAL SYSTEM FROM
THE WEST ON FRIDAY. HOWEVER THE WRF-GFS AND HIRES-ARW-W HAVE BACKED
OFF SLIGHTLY ON THE DURATION OF GALE FORCE WINDS...WITH THE
STRONGEST WINDS OVER THE COASTAL WATERS FRIDAY AFTERNOON...AND OVER
THE NORTH INTERIOR WATERS FRIDAY EVENING.

WESTERLY FLOW ALOFT OVER THE NE PACIFIC SATURDAY THROUGH MONDAY WILL
BRING SEVERAL WEAK SYSTEMS ACROSS THE AREA. KAM/CHB

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS EXCEPT CENTRAL STRAIT AND PUGET
     SOUND.
     GALE WATCH COAST FRIDAY.

&&

$$

WWW.WEATHER.GOV/SEATTLE

YOU CAN SEE AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML






000
FXUS66 KSEW 200501
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
900 PM PST WED NOV 19 2014

.SYNOPSIS...A FRONT WILL BRING SOME RAIN TONIGHT. ANOTHER STRONGER
FRONT WILL IMPACT THE AREA ON FRIDAY AND FRIDAY NIGHT...BRINGING
RAIN...WIND...AND SNOW TO THE MOUNTAINS. ADDITIONAL WEATHER SYSTEMS
WILL ARRIVE EVERY DAY OR TWO THROUGH THE MIDDLE OF NEXT WEEK.

&&

.SHORT TERM...A COLD FRONT WILL LIFT NORTH THROUGH WESTERN WA
TONIGHT BRINGING A LITTLE RAIN TO THE AREA. THE FRONT IS NOW
REACHING KHQM...BUT THERE ARE A FEW LIGHT SHOWERS ALSO AFFECTING THE
NORTH INTERIOR. EAST WINDS WILL KEEP TEMPS BELOW FREEZING IN THE
PASSES AND MAY SEE FREEZING RAIN AT SNOQUALMIE AND STEVENS PASS.
TEMPS WILL REMAIN ABOVE FREEZING ACROSS THE LOWLANDS TONIGHT. THIS
FRONT WILL EXIT NORTH THURSDAY MORNING WITH RAIN TAPERING DOWN. A
WEAK UPPER TROUGH WILL SHIFT INLAND FOR JUST ISOLATED TO SCATTERED
SHOWERS ACROSS THE REGION DURING THE AFTERNOON.

A STRONGER PAC SYSTEM WILL BRING WET AND WINDY WEATHER TO WESTERN WA
ON FRI. SO FAR MODELS ARE PRETTY CONSISTENT WITH THIS SYSTEM. RAIN
WILL BEGIN ON THE COAST FRI MORNING...WITH RAIN SPREADING INLAND BY
THE AFTERNOON. IT WILL BE WINDY ALONG THE COAST AND NORTH INTERIOR.
RAIN WILL CONTINUE THROUGH THE EVENING AS THE COLD FRONT MOVES
INLAND. THE SNOW LEVEL WILL LOWER TO AROUND 4000 FT FRIDAY NIGHT AND
STEVENS PASS MAY SEE A FEW INCHES OF SNOW...WITH WINTER WEATHER
ADVISORY AMOUNTS POSSIBLE AT MOUNT BAKER. THE AIR MASS WILL REMAIN
COOL AND UNSETTLED THROUGH EARLY SAT MORNING AS THE UPPER TROUGH
PASSES THROUGH.

ONSHORE FLOW WILL CONTINUE ON SAT FOR ADDITIONAL SHOWERS ACROSS THE
REGION. MAY ALSO SEE A PUGET SOUND CONVERGENCE ZONE DEVELOP IN
SNOHOMISH/KING COUNTIES...WITH MORE SNOW EXPECTED IN THE MOUNTAINS.
33

.LONG TERM...PREVIOUS DISCUSSION...A COUPLE MORE SHORTWAVE TROUGHS
WILL LIKELY IMPACT THE AREA ON SUNDAY AND MONDAY...KEEPING BREEZY
CONDITIONS AND PRECIPITATION IN THE FORECAST. ON TUESDAY...MODELS
ARE BEGINNING TO AGREE THAT A PLUME OF MOISTURE CARRIED BY THE JET
STREAM WILL IMPACT THE NORTHWEST...AS PREDICTED BY THE ECMWF
YESTERDAY. HOWEVER...A LOT OF UNCERTAINTY EXISTS AS TO WHERE THIS
MOISTURE WILL COME ASHORE...THE ECMWF HAS IT HITTING OREGON WHEREAS
THE GFS HAS IT IMPACTING NORTHWEST WASHINGTON AND SOUTHWEST BC.
THERE IS ALSO UNCERTAINTY AS TO WHETHER IT WILL BE ACCOMPANIED BY A
SURFACE LOW PRESSURE SYSTEM.

MODELS DISAGREE ON ABOUT JUST ABOUT EVERYTHING WEDNESDAY AND
BEYOND...SO THE FORECAST IS VERY UNCERTAIN AT THIS POINT. JSMITH

&&

.HYDROLOGY...RIVER FLOODING IS NOT EXPECTED IN THE NEXT 7 DAYS.

&&

.AVIATION...A COLD FRONT OVER THE OREGON OFFSHORE WATERS WILL MOVE
NORTHEAST ACROSS WESTERN WASHINGTON TONIGHT. CEILINGS BKN060-100
AHEAD OF THE FRONT WILL LOWER TO MVFR LEVELS WITH AND BEHIND THE
FRONT. LOCAL IFR CIGS ARE POSSIBLE AFTER 12Z. WEAK POST-FRONTAL
WESTERLY FLOW ALOFT WILL PREVAIL ON THURSDAY. A MOIST AIR MASS WILL
KEEP CEILINGS MAINLY IN THE 2000-5000 FOOT RANGE.

KSEA...GOOD VFR CONDITIONS WITH CEILINGS ABOVE BKN080-100 WILL
CONTINUE THROUGH ABOUT 08Z TONIGHT. RAIN FROM THE APPROACHING FRONT
SHOULD REACH THE TERMINAL AROUND 08Z WITH MVFR CEILINGS AFTER 09Z.
WINDS SOUTHEAST 6-10 KT. CHB

&&

.MARINE...A COLD FRONT APPROACHING FROM THE SOUTHWEST WILL MOVE
ACROSS WESTERN WASHINGTON LATE TONIGHT. MODERATE SOUTHEAST FLOW WILL
BRING SMALL CRAFT ADVISORY WINDS TO MOST WATERS. POST FRONT ADVISORY
LEVEL WINDS WILL CONTINUE THROUGH THURSDAY MORNING.

MODELS REMAIN CONSISTENT IN BRINGING A STRONGER FRONTAL SYSTEM FROM
THE WEST ON FRIDAY. HOWEVER THE WRF-GFS AND HIRES-ARW-W HAVE BACKED
OFF SLIGHTLY ON THE DURATION OF GALE FORCE WINDS...WITH THE
STRONGEST WINDS OVER THE COASTAL WATERS FRIDAY AFTERNOON...AND OVER
THE NORTH INTERIOR WATERS FRIDAY EVENING.

WESTERLY FLOW ALOFT OVER THE NE PACIFIC SATURDAY THROUGH MONDAY WILL
BRING SEVERAL WEAK SYSTEMS ACROSS THE AREA. KAM/CHB

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS EXCEPT CENTRAL STRAIT AND PUGET
     SOUND.
     GALE WATCH COAST FRIDAY.

&&

$$

WWW.WEATHER.GOV/SEATTLE

YOU CAN SEE AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML






000
FXUS66 KSEW 200501
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
900 PM PST WED NOV 19 2014

.SYNOPSIS...A FRONT WILL BRING SOME RAIN TONIGHT. ANOTHER STRONGER
FRONT WILL IMPACT THE AREA ON FRIDAY AND FRIDAY NIGHT...BRINGING
RAIN...WIND...AND SNOW TO THE MOUNTAINS. ADDITIONAL WEATHER SYSTEMS
WILL ARRIVE EVERY DAY OR TWO THROUGH THE MIDDLE OF NEXT WEEK.

&&

.SHORT TERM...A COLD FRONT WILL LIFT NORTH THROUGH WESTERN WA
TONIGHT BRINGING A LITTLE RAIN TO THE AREA. THE FRONT IS NOW
REACHING KHQM...BUT THERE ARE A FEW LIGHT SHOWERS ALSO AFFECTING THE
NORTH INTERIOR. EAST WINDS WILL KEEP TEMPS BELOW FREEZING IN THE
PASSES AND MAY SEE FREEZING RAIN AT SNOQUALMIE AND STEVENS PASS.
TEMPS WILL REMAIN ABOVE FREEZING ACROSS THE LOWLANDS TONIGHT. THIS
FRONT WILL EXIT NORTH THURSDAY MORNING WITH RAIN TAPERING DOWN. A
WEAK UPPER TROUGH WILL SHIFT INLAND FOR JUST ISOLATED TO SCATTERED
SHOWERS ACROSS THE REGION DURING THE AFTERNOON.

A STRONGER PAC SYSTEM WILL BRING WET AND WINDY WEATHER TO WESTERN WA
ON FRI. SO FAR MODELS ARE PRETTY CONSISTENT WITH THIS SYSTEM. RAIN
WILL BEGIN ON THE COAST FRI MORNING...WITH RAIN SPREADING INLAND BY
THE AFTERNOON. IT WILL BE WINDY ALONG THE COAST AND NORTH INTERIOR.
RAIN WILL CONTINUE THROUGH THE EVENING AS THE COLD FRONT MOVES
INLAND. THE SNOW LEVEL WILL LOWER TO AROUND 4000 FT FRIDAY NIGHT AND
STEVENS PASS MAY SEE A FEW INCHES OF SNOW...WITH WINTER WEATHER
ADVISORY AMOUNTS POSSIBLE AT MOUNT BAKER. THE AIR MASS WILL REMAIN
COOL AND UNSETTLED THROUGH EARLY SAT MORNING AS THE UPPER TROUGH
PASSES THROUGH.

ONSHORE FLOW WILL CONTINUE ON SAT FOR ADDITIONAL SHOWERS ACROSS THE
REGION. MAY ALSO SEE A PUGET SOUND CONVERGENCE ZONE DEVELOP IN
SNOHOMISH/KING COUNTIES...WITH MORE SNOW EXPECTED IN THE MOUNTAINS.
33

.LONG TERM...PREVIOUS DISCUSSION...A COUPLE MORE SHORTWAVE TROUGHS
WILL LIKELY IMPACT THE AREA ON SUNDAY AND MONDAY...KEEPING BREEZY
CONDITIONS AND PRECIPITATION IN THE FORECAST. ON TUESDAY...MODELS
ARE BEGINNING TO AGREE THAT A PLUME OF MOISTURE CARRIED BY THE JET
STREAM WILL IMPACT THE NORTHWEST...AS PREDICTED BY THE ECMWF
YESTERDAY. HOWEVER...A LOT OF UNCERTAINTY EXISTS AS TO WHERE THIS
MOISTURE WILL COME ASHORE...THE ECMWF HAS IT HITTING OREGON WHEREAS
THE GFS HAS IT IMPACTING NORTHWEST WASHINGTON AND SOUTHWEST BC.
THERE IS ALSO UNCERTAINTY AS TO WHETHER IT WILL BE ACCOMPANIED BY A
SURFACE LOW PRESSURE SYSTEM.

MODELS DISAGREE ON ABOUT JUST ABOUT EVERYTHING WEDNESDAY AND
BEYOND...SO THE FORECAST IS VERY UNCERTAIN AT THIS POINT. JSMITH

&&

.HYDROLOGY...RIVER FLOODING IS NOT EXPECTED IN THE NEXT 7 DAYS.

&&

.AVIATION...A COLD FRONT OVER THE OREGON OFFSHORE WATERS WILL MOVE
NORTHEAST ACROSS WESTERN WASHINGTON TONIGHT. CEILINGS BKN060-100
AHEAD OF THE FRONT WILL LOWER TO MVFR LEVELS WITH AND BEHIND THE
FRONT. LOCAL IFR CIGS ARE POSSIBLE AFTER 12Z. WEAK POST-FRONTAL
WESTERLY FLOW ALOFT WILL PREVAIL ON THURSDAY. A MOIST AIR MASS WILL
KEEP CEILINGS MAINLY IN THE 2000-5000 FOOT RANGE.

KSEA...GOOD VFR CONDITIONS WITH CEILINGS ABOVE BKN080-100 WILL
CONTINUE THROUGH ABOUT 08Z TONIGHT. RAIN FROM THE APPROACHING FRONT
SHOULD REACH THE TERMINAL AROUND 08Z WITH MVFR CEILINGS AFTER 09Z.
WINDS SOUTHEAST 6-10 KT. CHB

&&

.MARINE...A COLD FRONT APPROACHING FROM THE SOUTHWEST WILL MOVE
ACROSS WESTERN WASHINGTON LATE TONIGHT. MODERATE SOUTHEAST FLOW WILL
BRING SMALL CRAFT ADVISORY WINDS TO MOST WATERS. POST FRONT ADVISORY
LEVEL WINDS WILL CONTINUE THROUGH THURSDAY MORNING.

MODELS REMAIN CONSISTENT IN BRINGING A STRONGER FRONTAL SYSTEM FROM
THE WEST ON FRIDAY. HOWEVER THE WRF-GFS AND HIRES-ARW-W HAVE BACKED
OFF SLIGHTLY ON THE DURATION OF GALE FORCE WINDS...WITH THE
STRONGEST WINDS OVER THE COASTAL WATERS FRIDAY AFTERNOON...AND OVER
THE NORTH INTERIOR WATERS FRIDAY EVENING.

WESTERLY FLOW ALOFT OVER THE NE PACIFIC SATURDAY THROUGH MONDAY WILL
BRING SEVERAL WEAK SYSTEMS ACROSS THE AREA. KAM/CHB

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS EXCEPT CENTRAL STRAIT AND PUGET
     SOUND.
     GALE WATCH COAST FRIDAY.

&&

$$

WWW.WEATHER.GOV/SEATTLE

YOU CAN SEE AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML






000
FXUS66 KSEW 200501
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
900 PM PST WED NOV 19 2014

.SYNOPSIS...A FRONT WILL BRING SOME RAIN TONIGHT. ANOTHER STRONGER
FRONT WILL IMPACT THE AREA ON FRIDAY AND FRIDAY NIGHT...BRINGING
RAIN...WIND...AND SNOW TO THE MOUNTAINS. ADDITIONAL WEATHER SYSTEMS
WILL ARRIVE EVERY DAY OR TWO THROUGH THE MIDDLE OF NEXT WEEK.

&&

.SHORT TERM...A COLD FRONT WILL LIFT NORTH THROUGH WESTERN WA
TONIGHT BRINGING A LITTLE RAIN TO THE AREA. THE FRONT IS NOW
REACHING KHQM...BUT THERE ARE A FEW LIGHT SHOWERS ALSO AFFECTING THE
NORTH INTERIOR. EAST WINDS WILL KEEP TEMPS BELOW FREEZING IN THE
PASSES AND MAY SEE FREEZING RAIN AT SNOQUALMIE AND STEVENS PASS.
TEMPS WILL REMAIN ABOVE FREEZING ACROSS THE LOWLANDS TONIGHT. THIS
FRONT WILL EXIT NORTH THURSDAY MORNING WITH RAIN TAPERING DOWN. A
WEAK UPPER TROUGH WILL SHIFT INLAND FOR JUST ISOLATED TO SCATTERED
SHOWERS ACROSS THE REGION DURING THE AFTERNOON.

A STRONGER PAC SYSTEM WILL BRING WET AND WINDY WEATHER TO WESTERN WA
ON FRI. SO FAR MODELS ARE PRETTY CONSISTENT WITH THIS SYSTEM. RAIN
WILL BEGIN ON THE COAST FRI MORNING...WITH RAIN SPREADING INLAND BY
THE AFTERNOON. IT WILL BE WINDY ALONG THE COAST AND NORTH INTERIOR.
RAIN WILL CONTINUE THROUGH THE EVENING AS THE COLD FRONT MOVES
INLAND. THE SNOW LEVEL WILL LOWER TO AROUND 4000 FT FRIDAY NIGHT AND
STEVENS PASS MAY SEE A FEW INCHES OF SNOW...WITH WINTER WEATHER
ADVISORY AMOUNTS POSSIBLE AT MOUNT BAKER. THE AIR MASS WILL REMAIN
COOL AND UNSETTLED THROUGH EARLY SAT MORNING AS THE UPPER TROUGH
PASSES THROUGH.

ONSHORE FLOW WILL CONTINUE ON SAT FOR ADDITIONAL SHOWERS ACROSS THE
REGION. MAY ALSO SEE A PUGET SOUND CONVERGENCE ZONE DEVELOP IN
SNOHOMISH/KING COUNTIES...WITH MORE SNOW EXPECTED IN THE MOUNTAINS.
33

.LONG TERM...PREVIOUS DISCUSSION...A COUPLE MORE SHORTWAVE TROUGHS
WILL LIKELY IMPACT THE AREA ON SUNDAY AND MONDAY...KEEPING BREEZY
CONDITIONS AND PRECIPITATION IN THE FORECAST. ON TUESDAY...MODELS
ARE BEGINNING TO AGREE THAT A PLUME OF MOISTURE CARRIED BY THE JET
STREAM WILL IMPACT THE NORTHWEST...AS PREDICTED BY THE ECMWF
YESTERDAY. HOWEVER...A LOT OF UNCERTAINTY EXISTS AS TO WHERE THIS
MOISTURE WILL COME ASHORE...THE ECMWF HAS IT HITTING OREGON WHEREAS
THE GFS HAS IT IMPACTING NORTHWEST WASHINGTON AND SOUTHWEST BC.
THERE IS ALSO UNCERTAINTY AS TO WHETHER IT WILL BE ACCOMPANIED BY A
SURFACE LOW PRESSURE SYSTEM.

MODELS DISAGREE ON ABOUT JUST ABOUT EVERYTHING WEDNESDAY AND
BEYOND...SO THE FORECAST IS VERY UNCERTAIN AT THIS POINT. JSMITH

&&

.HYDROLOGY...RIVER FLOODING IS NOT EXPECTED IN THE NEXT 7 DAYS.

&&

.AVIATION...A COLD FRONT OVER THE OREGON OFFSHORE WATERS WILL MOVE
NORTHEAST ACROSS WESTERN WASHINGTON TONIGHT. CEILINGS BKN060-100
AHEAD OF THE FRONT WILL LOWER TO MVFR LEVELS WITH AND BEHIND THE
FRONT. LOCAL IFR CIGS ARE POSSIBLE AFTER 12Z. WEAK POST-FRONTAL
WESTERLY FLOW ALOFT WILL PREVAIL ON THURSDAY. A MOIST AIR MASS WILL
KEEP CEILINGS MAINLY IN THE 2000-5000 FOOT RANGE.

KSEA...GOOD VFR CONDITIONS WITH CEILINGS ABOVE BKN080-100 WILL
CONTINUE THROUGH ABOUT 08Z TONIGHT. RAIN FROM THE APPROACHING FRONT
SHOULD REACH THE TERMINAL AROUND 08Z WITH MVFR CEILINGS AFTER 09Z.
WINDS SOUTHEAST 6-10 KT. CHB

&&

.MARINE...A COLD FRONT APPROACHING FROM THE SOUTHWEST WILL MOVE
ACROSS WESTERN WASHINGTON LATE TONIGHT. MODERATE SOUTHEAST FLOW WILL
BRING SMALL CRAFT ADVISORY WINDS TO MOST WATERS. POST FRONT ADVISORY
LEVEL WINDS WILL CONTINUE THROUGH THURSDAY MORNING.

MODELS REMAIN CONSISTENT IN BRINGING A STRONGER FRONTAL SYSTEM FROM
THE WEST ON FRIDAY. HOWEVER THE WRF-GFS AND HIRES-ARW-W HAVE BACKED
OFF SLIGHTLY ON THE DURATION OF GALE FORCE WINDS...WITH THE
STRONGEST WINDS OVER THE COASTAL WATERS FRIDAY AFTERNOON...AND OVER
THE NORTH INTERIOR WATERS FRIDAY EVENING.

WESTERLY FLOW ALOFT OVER THE NE PACIFIC SATURDAY THROUGH MONDAY WILL
BRING SEVERAL WEAK SYSTEMS ACROSS THE AREA. KAM/CHB

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS EXCEPT CENTRAL STRAIT AND PUGET
     SOUND.
     GALE WATCH COAST FRIDAY.

&&

$$

WWW.WEATHER.GOV/SEATTLE

YOU CAN SEE AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML






000
FXUS66 KPQR 200051 AAA
AFDPQR

AREA FORECAST DISCUSSION...RESENT
NATIONAL WEATHER SERVICE PORTLAND OR
451 PM PST WED NOV 19 2014

.SYNOPSIS...RAIN WILL SPREAD ACROSS THE REGION THIS EVENING. THE
RAIN WILL MAINLY FALL AS FREEZING RAIN FOR THE COLUMBIA RIVER GORGE
BUT EXPECT TO SEE PERIODS OF SLEET AS WELL. TEMPERATURES WILL
MODERATE TO NEAR NORMAL BUT STILL REMAIN A BIT COOLER FOR AREAS
UNDER THE GORGE WIND INFLUENCE DURING THIS PERIOD. A STRONGER WET
AND WINDY STORM SYSTEM WILL ARRIVE FRIDAY. ADDITIONAL ROUNDS OF RAIN
WILL FALL OVER THE WEEKEND. LOWER SNOW LEVELS MAY BRING SIGNIFICANT
SNOW ACCUMULATIONS TO THE CASCADES PASSES OVER THE WEEKEND.
CURRENTLY...BEST TIMES TO CROSS THE OREGON PASSES APPEAR TO BE
FRIDAY AND SUNDAY MORNINGS.

&&

.SHORT TERM...TONIGHT THROUGH SATURDAY...MAIN ISSUE FOR TONIGHT
CONTINUES TO REVOLVE AROUND A FREEZING RAIN ADVISORY FOR THE GORGE
AND UPPER HOOD RIVER VALLEY. COLD POOL EAST OF THE CASCADES REMAINS
WELL ENTRENCHED. EASTERLY PRESSURE GRADIENT BETWEEN THE DALLES AND
TROUTDALE PEAKED AGAIN THIS MORNING THIS TIME AT 11.6 MB AND
CURRENTLY SITS AROUND 10 MB. WILL CONTINUE TO SEE THE GUSTY EAST
WINDS DRAW THAT COLD AIR THROUGH THE GORGE UNTIL GRADIENTS EASE
OVERNIGHT. THEY WILL STAY LIGHT EASTERLY HOWEVER SO HAVE SIGNIFICANT
DOUBTS THE GORGE...AND ESPECIALLY THE CENTRAL GORGE...WILL GET MUCH
WARMER OVER THE NEXT COUPLE DAYS. THE SYSTEM COMING IN TONIGHT STILL
LOOKS LIKE IT WILL HOLD TOGETHER ENOUGH TO BRING A NOTABLE THREAT OF
FREEZING RAIN AND/OR SLEET TO THE GORGE AREAS PRIMARILY EAST OF
SKAMANIA BUT EXPECT THE COLDER AIR WILL CONTINUE TO SEEP FURTHER
WEST AS WELL AND HAVE SOME IMPACTS CLOSER TO CORBETT. THE REST OF
THE REGION WEST OF THE CASCADES HAS WARMED UNDER THE ENCROACHING
MARITIME AIR MASS. THE AIR MASS EAST OF THE CREST REMAINS STAUNCHLY
CONTINENTAL WITH SUB-FREEZING TEMPERATURES EXCEEDING 3 KFT NEAR THE
DALLES. GIVEN THOSE FACTORS...MAY SEE MORE OF A SLEET STORM FOR THE
CENTRAL GORGE AND UPPER HOOD RIVER VALLEY EARLY THIS EVENING BEFORE
THE WARM AIR PUSHES OVER THE CASCADES. WILL THEN SEE FREEZING RAIN
DOMINATE LATER OVERNIGHT AND INTO THURSDAY MORNING. DECIDED TO KEEP
THE ADVISORY AS DOMINANT FREEZING RAIN BUT ALSO ADDED THE SLEET
MENTION FOR A FEW HOURS AT THE ONSET.

EXPECT THE PRIMARY THREAT TO BE OVER BY 12Z/4AM THURSDAY BUT DO
EXPECT FURTHER VERY LIGHT ACCUMULATIONS THROUGH A LARGE PART OF THE
DAY ACROSS THE ENTIRE AREA AS ANOTHER DEVELOPING SHORT WAVE WILL
LARGELY SLIDE SOUTH OF OUR AREA AND MAINLY INTO NORTHERN CALIFORNIA.
THERE WILL BE AREAS OF DEFORMATION OVER US TO PRODUCE MORE OF A
HYBRID STRATIFORM/SHOWER PRECIP SCENARIO. SNOW LEVELS WILL BEGIN
RISING RAPIDLY BY EARLY FRIDAY AS WARM FRONTAL RAIN UNDER MOIST
ZONAL PACIFIC FLOW SPREADS FROM WEST TO EAST. BY THEMSELVES...QPF
AMOUNTS ARE FAIRLY MODEST BUT DO APPROACH AN INCH ENDING SATURDAY
EVENING FOR THE VALLEYS AND A LITTLE OVER 2 INCHES FOR THE CASCADES
AND COAST RANGE. SNOW LEVELS STAY HIGH UNTIL THE COLD FRONT DOES
CROSS OVERNIGHT FRIDAY NIGHT. EXPECT TO SEE A FEW INCHES OF PASS
LEVEL ACCUMULATION LATER FRIDAY AND FRIDAY NIGHT JUST AHEAD OF THE
FRONT BUT THE MOISTURE EASES AFTER THE FRONT WITH SNOW LEVELS
FALLING TO AROUND 3000 FEET. HAVE ISSUED A SPECIAL WEATHER STATEMENT
FOR THE EXPECTED SNOW THIS WEEKEND.

AS MENTIONED PREVIOUSLY...DONT YET HAVE MUCH FAITH IN MODELED GORGE
TEMPERATURES RISING ABOVE FREEZING UNTIL PERHAPS LATER FRIDAY NIGHT
OR SATURDAY MORNING WHEN THE SURFACE PRESSURE GRADIENT TRULY BECOMES
WESTERLY. EXPERIENCE SHOWS MODELS ATTEMPT TO WARM UP THE GORGE BY
MIXING FROM ABOVE BUT THE COLDER DENSER AIR FROM EAST OF THE
CASCADES COMMONLY UNDERCUTS THAT MIXED LAYER UNTIL A SOLID WESTERLY
WIND PUSHES THROUGH THE LOWEST TERRAIN. AS SUCH WILL BE KEEPING A
CLOSE EYE ON WHAT ACTUALLY OCCURS TONIGHT AND EARLY TOMORROW. IF THE
HUNCH IS CORRECT...THE INCOMING SYSTEM FRIDAY COULD PRESENT A
SIGNIFICANT THREAT FOR AN ICE STORM COVERING AT LEAST THE CENTRAL
GORGE AND HOOD RIVER VALLEY...IF NOT THE WESTERN GORGE AS WELL. THE
ONE FACTOR IN FAVOR OF THE WARMING IS WE ARE STILL ON THE DOWNWARD
GLIDE SLOPE HEADING INTO CALENDAR WINTER. DECIDED TO HOLD OFF AND
TOW THE MODEL LINE REGARDING IMPROVING TEMPERATURES FOR NOW BUT
EXPECT THAT IF CONDITIONS REMAIN SUB-FREEZING NEAR AND EAST OF HOOD
RIVER...FRIDAY NIGHT COULD BE FAIRLY ICY. /JBONK

.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY. THE MORE WESTERLY OR
ZONAL FLOW THAT SETS UP LATE IN THE SHORT TERM PERIOD CONTINUES INTO
THE LONG TERM PERIOD...WITH OCCASIONAL RAIN AS DISTURBANCES MOVE
THROUGH. SOME RIDGING DEVELOPS IN THE NORTHEAST PACIFIC EARLY NEXT
WEEK...THOUGH THE MODELS VARY ON HOW MUCH. THE NORMALLY MORE
RELIABLE ECMWF MODEL HAS FLATTER RIDGING WITH MORE OF A DIRTY RIDGE
TYPE PATTERN AND DOES BRING SOME PRECIPITATION INTO THE FORECAST
AREA AT TIMES...WHILE THE OPERATIONAL GFS MODEL SHOWS MORE AMPLITUDE
DEVELOPING AND POSSIBLY SOME DRYING. THE PARALLEL VERSION OF THE GFS
MODEL IS A BIT MORE LIKE THE ECMWF. HAVE KEPT OUR CURRENT TRENDS
WHICH ARE MORE LIKE THE ECMWF AND THE PARALLEL GFS MODEL...THOUGH
CONFIDENCE IN ANY DETAILS ARE NOT VERY HIGH AT THIS POINT. TOLLESON
&&

.AVIATION...CURRENTLY WARM FRONTAL RAIN LOOKS TO BE NEAR KONP...SEEN
ON RADAR...PROGRESSING NORTHWARD. WARMER AIR MASS BEHIND FRONT
WILL LIKELY LOWER CIGS AT KEUG...SLE...AND COASTAL SITES TO MVFR
OR POSSIBLY EVEN IFR OVERNIGHT TONIGHT. DRY EASTERLY WINDS OUT OF
THE GORGE AT KTTD ARE STILL 25 KT GUSTING TO 35 KT THIS AFTERNOON.
THIS WILL PERSIST UNTIL AROUND 06Z THURSDAY WHEN THE FRONT MAKES
IT TO THE NORTH WILLAMETTE VALLEY. CHANCE OF RAIN AND MVFR
CONDITIONS PERSISTS THROUGH THURSDAY AFTERNOON...ESPECIALLY AFTER
12Z WHEN SOUTHERLY WINDS WEAKEN ACROSS THE AREA. AFTER THIS
TIME...CIGS AT LOCATIONS IN THE NORTHERN WILLAMETTE VALLEY COULD
DROP TO MVFR.


KPDX AND APPROACHES...VFR PREVAILING THROUGH EARLY THIS EVENING AS
DRY EASTERLY FLOW CONTINUES. AFTER ABOUT 12Z THURSDAY INCREASING
RAIN MAY BRING MVFR TO IFR CONDITIONS AFTER DRY EASTERLY WINDS OUT
OF THE GORGE BEGIN TO SUBSIDE AROUND 06Z.

-MCCOY

&&

.MARINE...WIND GENERALLY AROUND 15 TO 20 KTS GUSTS FREQUENTLY
REACHING 25 KTS AND WILL STAY ABOVE CRITERIA UNTIL EARLY THURSDAY.
SEAS 8 TO 10 FT CURRENTLY AND WILL CONTINUE TO BUILD TONIGHT TO
AROUND 13 FT BEFORE STARTING TO SUBSIDE AFTER MIDNIGHT. BY
THURSDAY MORNING SEAS WILL BE BACK DOWN TO AROUND 9 TO 10 FT.

STRONGER WEATHER SYSTEM WILL MOVE THROUGH ON FRIDAY. GALES ARE
VERY POSSIBLE ON FRIDAY AHEAD OF FRONTAL PASSAGE ACROSS OUR
WATERS. THURSDAY SEAS WILL HOVER AROUND 9 TO 10 FT BEFORE START
TO BUILD AGAIN EARLY FRIDAY. WAVE HEIGHTS WILL REACH THE MIDDLE
TEENS BY MID-DAY FRIDAY AND COULD EVEN GET INTO THE UPPER TEENS
ACROSS THE SOUTHERN WATERS WITH GALE FORCE WINDS POSSIBLE IN THIS
AREA. WINDS AND SEAS WILL SUBSIDE SATURDAY TO 10 TO 11 FT...AND SEAS
LOOK TO REMAIN ABOVE 10 FT THROUGH THE WEEKEND.

-MCCOY

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING RAIN ADVISORY FROM 6 PM THIS EVENING TO 4 AM PST
     THURSDAY FOR CENTRAL COLUMBIA RIVER GORGE-UPPER HOOD RIVER
     VALLEY-WESTERN COLUMBIA RIVER GORGE.

WA...FREEZING RAIN ADVISORY FROM 6 PM THIS EVENING TO 4 AM PST
     THURSDAY FOR CENTRAL COLUMBIA RIVER GORGE-WESTERN COLUMBIA
     RIVER GORGE.

PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 AM PST THURSDAY FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 AM PST THURSDAY
     FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

&&


$$

INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND

THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.



000
FXUS66 KPQR 200051 AAA
AFDPQR

AREA FORECAST DISCUSSION...RESENT
NATIONAL WEATHER SERVICE PORTLAND OR
451 PM PST WED NOV 19 2014

.SYNOPSIS...RAIN WILL SPREAD ACROSS THE REGION THIS EVENING. THE
RAIN WILL MAINLY FALL AS FREEZING RAIN FOR THE COLUMBIA RIVER GORGE
BUT EXPECT TO SEE PERIODS OF SLEET AS WELL. TEMPERATURES WILL
MODERATE TO NEAR NORMAL BUT STILL REMAIN A BIT COOLER FOR AREAS
UNDER THE GORGE WIND INFLUENCE DURING THIS PERIOD. A STRONGER WET
AND WINDY STORM SYSTEM WILL ARRIVE FRIDAY. ADDITIONAL ROUNDS OF RAIN
WILL FALL OVER THE WEEKEND. LOWER SNOW LEVELS MAY BRING SIGNIFICANT
SNOW ACCUMULATIONS TO THE CASCADES PASSES OVER THE WEEKEND.
CURRENTLY...BEST TIMES TO CROSS THE OREGON PASSES APPEAR TO BE
FRIDAY AND SUNDAY MORNINGS.

&&

.SHORT TERM...TONIGHT THROUGH SATURDAY...MAIN ISSUE FOR TONIGHT
CONTINUES TO REVOLVE AROUND A FREEZING RAIN ADVISORY FOR THE GORGE
AND UPPER HOOD RIVER VALLEY. COLD POOL EAST OF THE CASCADES REMAINS
WELL ENTRENCHED. EASTERLY PRESSURE GRADIENT BETWEEN THE DALLES AND
TROUTDALE PEAKED AGAIN THIS MORNING THIS TIME AT 11.6 MB AND
CURRENTLY SITS AROUND 10 MB. WILL CONTINUE TO SEE THE GUSTY EAST
WINDS DRAW THAT COLD AIR THROUGH THE GORGE UNTIL GRADIENTS EASE
OVERNIGHT. THEY WILL STAY LIGHT EASTERLY HOWEVER SO HAVE SIGNIFICANT
DOUBTS THE GORGE...AND ESPECIALLY THE CENTRAL GORGE...WILL GET MUCH
WARMER OVER THE NEXT COUPLE DAYS. THE SYSTEM COMING IN TONIGHT STILL
LOOKS LIKE IT WILL HOLD TOGETHER ENOUGH TO BRING A NOTABLE THREAT OF
FREEZING RAIN AND/OR SLEET TO THE GORGE AREAS PRIMARILY EAST OF
SKAMANIA BUT EXPECT THE COLDER AIR WILL CONTINUE TO SEEP FURTHER
WEST AS WELL AND HAVE SOME IMPACTS CLOSER TO CORBETT. THE REST OF
THE REGION WEST OF THE CASCADES HAS WARMED UNDER THE ENCROACHING
MARITIME AIR MASS. THE AIR MASS EAST OF THE CREST REMAINS STAUNCHLY
CONTINENTAL WITH SUB-FREEZING TEMPERATURES EXCEEDING 3 KFT NEAR THE
DALLES. GIVEN THOSE FACTORS...MAY SEE MORE OF A SLEET STORM FOR THE
CENTRAL GORGE AND UPPER HOOD RIVER VALLEY EARLY THIS EVENING BEFORE
THE WARM AIR PUSHES OVER THE CASCADES. WILL THEN SEE FREEZING RAIN
DOMINATE LATER OVERNIGHT AND INTO THURSDAY MORNING. DECIDED TO KEEP
THE ADVISORY AS DOMINANT FREEZING RAIN BUT ALSO ADDED THE SLEET
MENTION FOR A FEW HOURS AT THE ONSET.

EXPECT THE PRIMARY THREAT TO BE OVER BY 12Z/4AM THURSDAY BUT DO
EXPECT FURTHER VERY LIGHT ACCUMULATIONS THROUGH A LARGE PART OF THE
DAY ACROSS THE ENTIRE AREA AS ANOTHER DEVELOPING SHORT WAVE WILL
LARGELY SLIDE SOUTH OF OUR AREA AND MAINLY INTO NORTHERN CALIFORNIA.
THERE WILL BE AREAS OF DEFORMATION OVER US TO PRODUCE MORE OF A
HYBRID STRATIFORM/SHOWER PRECIP SCENARIO. SNOW LEVELS WILL BEGIN
RISING RAPIDLY BY EARLY FRIDAY AS WARM FRONTAL RAIN UNDER MOIST
ZONAL PACIFIC FLOW SPREADS FROM WEST TO EAST. BY THEMSELVES...QPF
AMOUNTS ARE FAIRLY MODEST BUT DO APPROACH AN INCH ENDING SATURDAY
EVENING FOR THE VALLEYS AND A LITTLE OVER 2 INCHES FOR THE CASCADES
AND COAST RANGE. SNOW LEVELS STAY HIGH UNTIL THE COLD FRONT DOES
CROSS OVERNIGHT FRIDAY NIGHT. EXPECT TO SEE A FEW INCHES OF PASS
LEVEL ACCUMULATION LATER FRIDAY AND FRIDAY NIGHT JUST AHEAD OF THE
FRONT BUT THE MOISTURE EASES AFTER THE FRONT WITH SNOW LEVELS
FALLING TO AROUND 3000 FEET. HAVE ISSUED A SPECIAL WEATHER STATEMENT
FOR THE EXPECTED SNOW THIS WEEKEND.

AS MENTIONED PREVIOUSLY...DONT YET HAVE MUCH FAITH IN MODELED GORGE
TEMPERATURES RISING ABOVE FREEZING UNTIL PERHAPS LATER FRIDAY NIGHT
OR SATURDAY MORNING WHEN THE SURFACE PRESSURE GRADIENT TRULY BECOMES
WESTERLY. EXPERIENCE SHOWS MODELS ATTEMPT TO WARM UP THE GORGE BY
MIXING FROM ABOVE BUT THE COLDER DENSER AIR FROM EAST OF THE
CASCADES COMMONLY UNDERCUTS THAT MIXED LAYER UNTIL A SOLID WESTERLY
WIND PUSHES THROUGH THE LOWEST TERRAIN. AS SUCH WILL BE KEEPING A
CLOSE EYE ON WHAT ACTUALLY OCCURS TONIGHT AND EARLY TOMORROW. IF THE
HUNCH IS CORRECT...THE INCOMING SYSTEM FRIDAY COULD PRESENT A
SIGNIFICANT THREAT FOR AN ICE STORM COVERING AT LEAST THE CENTRAL
GORGE AND HOOD RIVER VALLEY...IF NOT THE WESTERN GORGE AS WELL. THE
ONE FACTOR IN FAVOR OF THE WARMING IS WE ARE STILL ON THE DOWNWARD
GLIDE SLOPE HEADING INTO CALENDAR WINTER. DECIDED TO HOLD OFF AND
TOW THE MODEL LINE REGARDING IMPROVING TEMPERATURES FOR NOW BUT
EXPECT THAT IF CONDITIONS REMAIN SUB-FREEZING NEAR AND EAST OF HOOD
RIVER...FRIDAY NIGHT COULD BE FAIRLY ICY. /JBONK

.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY. THE MORE WESTERLY OR
ZONAL FLOW THAT SETS UP LATE IN THE SHORT TERM PERIOD CONTINUES INTO
THE LONG TERM PERIOD...WITH OCCASIONAL RAIN AS DISTURBANCES MOVE
THROUGH. SOME RIDGING DEVELOPS IN THE NORTHEAST PACIFIC EARLY NEXT
WEEK...THOUGH THE MODELS VARY ON HOW MUCH. THE NORMALLY MORE
RELIABLE ECMWF MODEL HAS FLATTER RIDGING WITH MORE OF A DIRTY RIDGE
TYPE PATTERN AND DOES BRING SOME PRECIPITATION INTO THE FORECAST
AREA AT TIMES...WHILE THE OPERATIONAL GFS MODEL SHOWS MORE AMPLITUDE
DEVELOPING AND POSSIBLY SOME DRYING. THE PARALLEL VERSION OF THE GFS
MODEL IS A BIT MORE LIKE THE ECMWF. HAVE KEPT OUR CURRENT TRENDS
WHICH ARE MORE LIKE THE ECMWF AND THE PARALLEL GFS MODEL...THOUGH
CONFIDENCE IN ANY DETAILS ARE NOT VERY HIGH AT THIS POINT. TOLLESON
&&

.AVIATION...CURRENTLY WARM FRONTAL RAIN LOOKS TO BE NEAR KONP...SEEN
ON RADAR...PROGRESSING NORTHWARD. WARMER AIR MASS BEHIND FRONT
WILL LIKELY LOWER CIGS AT KEUG...SLE...AND COASTAL SITES TO MVFR
OR POSSIBLY EVEN IFR OVERNIGHT TONIGHT. DRY EASTERLY WINDS OUT OF
THE GORGE AT KTTD ARE STILL 25 KT GUSTING TO 35 KT THIS AFTERNOON.
THIS WILL PERSIST UNTIL AROUND 06Z THURSDAY WHEN THE FRONT MAKES
IT TO THE NORTH WILLAMETTE VALLEY. CHANCE OF RAIN AND MVFR
CONDITIONS PERSISTS THROUGH THURSDAY AFTERNOON...ESPECIALLY AFTER
12Z WHEN SOUTHERLY WINDS WEAKEN ACROSS THE AREA. AFTER THIS
TIME...CIGS AT LOCATIONS IN THE NORTHERN WILLAMETTE VALLEY COULD
DROP TO MVFR.


KPDX AND APPROACHES...VFR PREVAILING THROUGH EARLY THIS EVENING AS
DRY EASTERLY FLOW CONTINUES. AFTER ABOUT 12Z THURSDAY INCREASING
RAIN MAY BRING MVFR TO IFR CONDITIONS AFTER DRY EASTERLY WINDS OUT
OF THE GORGE BEGIN TO SUBSIDE AROUND 06Z.

-MCCOY

&&

.MARINE...WIND GENERALLY AROUND 15 TO 20 KTS GUSTS FREQUENTLY
REACHING 25 KTS AND WILL STAY ABOVE CRITERIA UNTIL EARLY THURSDAY.
SEAS 8 TO 10 FT CURRENTLY AND WILL CONTINUE TO BUILD TONIGHT TO
AROUND 13 FT BEFORE STARTING TO SUBSIDE AFTER MIDNIGHT. BY
THURSDAY MORNING SEAS WILL BE BACK DOWN TO AROUND 9 TO 10 FT.

STRONGER WEATHER SYSTEM WILL MOVE THROUGH ON FRIDAY. GALES ARE
VERY POSSIBLE ON FRIDAY AHEAD OF FRONTAL PASSAGE ACROSS OUR
WATERS. THURSDAY SEAS WILL HOVER AROUND 9 TO 10 FT BEFORE START
TO BUILD AGAIN EARLY FRIDAY. WAVE HEIGHTS WILL REACH THE MIDDLE
TEENS BY MID-DAY FRIDAY AND COULD EVEN GET INTO THE UPPER TEENS
ACROSS THE SOUTHERN WATERS WITH GALE FORCE WINDS POSSIBLE IN THIS
AREA. WINDS AND SEAS WILL SUBSIDE SATURDAY TO 10 TO 11 FT...AND SEAS
LOOK TO REMAIN ABOVE 10 FT THROUGH THE WEEKEND.

-MCCOY

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING RAIN ADVISORY FROM 6 PM THIS EVENING TO 4 AM PST
     THURSDAY FOR CENTRAL COLUMBIA RIVER GORGE-UPPER HOOD RIVER
     VALLEY-WESTERN COLUMBIA RIVER GORGE.

WA...FREEZING RAIN ADVISORY FROM 6 PM THIS EVENING TO 4 AM PST
     THURSDAY FOR CENTRAL COLUMBIA RIVER GORGE-WESTERN COLUMBIA
     RIVER GORGE.

PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 AM PST THURSDAY FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 AM PST THURSDAY
     FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

&&


$$

INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND

THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.




000
FXUS66 KOTX 192344
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
344 PM PST WED NOV 19 2014

.SYNOPSIS...
A weak weather system will arrive late tonight into Thursday with
the potential for a light wintry mix of rain...snow...and freezing
rain. A stronger, wetter and windier weather system will arrive
Friday persisting into the weekend with heavy snow amounts
possible over the mountains. The weather pattern will remain
active through the middle of next week.

&&

.DISCUSSION...

Tonight and Tomorrow....The lingering very narrow and elongated
ridging nested between longwave trofs in the vicinity of the
Aleutian Islands and Eastern North America will continue to act as
a barrier toward effective passage of weather systems through the
region. Disturbances that have tried to penetrate this ridge
continue to be weakened and sheared apart as they move through the
ridge. The expectation similar weakening and splitting will occur
with weak wrapped up warm frontal band spiraling outward from a
low pressure system working east into this ridge that is expected
to pass through Eastern Washington and Northern Idaho late tonight
and Tomorrow. With this scenario in mind cloud cover ramps up
depicting the system passage. Additionally very light QPF and snow
amounts are assigned to any locations where the pops are high,
otherwise very low pops are assigned. The warm air advection
associated with the warm front gliding over the cool air we have
in place near the surface is likely to warm to as much as +3 C or
so in spots which would allow enough melting of any falling frozen
precipitation at the upper levels to refreeze at the surface in
some locations, generally south of I-90 so a mention of light
freezing precipitation in the form of either light freezing rain
or drizzle continues to be utilized. The emphasis on this system
being weak and not doing much in terms of mixing the atmosphere
and not producing much precipitation supports the extension of the
ongoing air stagnation advisory into Friday. /Pelatti


VALLEY RAIN AND HEAVY MOUNTAIN SNOW POSSIBLE EARLY THIS WEEKEND

Tonight through Saturday...The breakdown of the current ridge will
continue through this period with a second weak wave transiting
the region Thursday night...mainly impacting the north eastern
zones with light and largely non-accumulating snow showers or
flurries. This will be another shearing wave in a developing
northern branch flow above a deep trough over the Great Basin.
Very little and weak dynamic support as well as a westerly flow in
the mid levels will probably allow this system to skip the deep
basin where the main threat of freezing rain would be with
residual arctic air slow to scrub. As it stands the main threat
will be the potential for freezing drizzle Friday morning in the
Ritzville to Moses Lake area embedded in stubborn fog in this low
laying area. Otherwise for most locations outside of the Cascades
Friday will be a seasonably cool and cloudy day. With these weak
impulses doing little to impact the boundary layer the Air
Stagnation Advisory will remain valid through noon Friday with
re-evaluation with area AQ authorities on Friday morning.

The next Pacific storm system promises to be a much wetter and
more dynamic beast. The latest NAM...GFS and ECMWF models are in
pretty good agreement regarding the timing an character of this
storm...currently visible on satellite as a large baroclinic leaf
cloud shield way out near 160W south of the Aleutians. While the
details of the frontal complex are somewhat confused...in general
a strong moist warm front through much of Friday night will be
followed by a breezy and gusty cold front during the day on
Saturday. Rich moisture will efficiently lift over the warm front
which will develop Friday afternoon over the Cascades and envelop
the entire forecast area Friday night and Saturday morning.
Precipitation will likely be almost universal...and the storm
will be strong enough to decisively scour the basin out as snow
levels rise. While mainly rain is expected in the basin and
valleys of the Idaho Panhandle and northeast mountains...the
scouring process will be retarded in the Cascade valleys
particularly north of lake Chelan...and the high terrain of the
Waterville Plateau may also hold onto snow through much of the
night. Winter Storm Watches for this storm will be issued with the
afternoon package for the Cascades in general and the mountains of
northeast Washington and north Idaho above 4000 feet.

On Saturday the cold front will move through the Cascades early in
the day promoting a downslope shutdown of steady snow except for
slop-over off the crest. The front will cross the basin and bring
gusty winds...possibly 30 to 35 mph over the exposed terrain of
the eastern basin...and promote lingering snow showers piling into
the Idaho Panhandle mountains. Temperatures on Saturday will feel
mild after the last week with a well mixed air mass promoting
adiabatic compressional warming. /Fugazzi

Saturday night and Sunday: A shortwave trough will be pushing
through the region during this period. The ECMWF has sped up
to become more in line with the GFS on the timing of this
trough. The precip associated with this system will be mainly rain
for the Columbia Basin with a few flurries and snow for the
mountains. The mountain passes can expect to receive around 3
inches from this system. The northern mountains are expected to
receive at most an inch. Daytime temperatures will range from the
upper 30s to low 40s. The nighttime temperatures will range from
the upper 20s to low 30s. This could produce icy patches along the
roads during the night and early morning hours throughout the
Inland Northwest. /JDC

Monday through Wednesday: Model discrepancy is high out this far
in the forecast period. The ECMWF and GFS model runs show a more
active weather regime; whereas, the Canadian model shows a strong
ridge building in over the region with a return of drier and
stable conditions. The Canadian solution is the outlier and was
ignored. The difference between the GFS and ECMWF solutions is
that the GFS shows more of a zonal flow pattern setting up over
the region with stronger connections to a sub-tropical moisture
fetch. The ECMWF model continues with a more northwest oriented
flow pattern and takes the bulk of the moisture off of the Pacific
into Oregon, which then only clips the southern portion of the
forecast area. The GFS solution would result in a wetter and
milder scenario and a better chance for snow levels to rise above
valley floors. The ECMWF is colder and keeps a chance for valley
snow across much of the region. I decided to take more of a
compromise between these two solutions as each have equal merit.
I kept precip chances near to or above climatology with rain
across the basin and transitioning to snow across the northern
mountain valleys; confidence this far out in the forecast period
is low at this time due to model uncertainty. /SVH


&&

.AVIATION...
00Z TAFS: Ridge of high pressure keeps VFR conditions prevailing
for most aviation sites until about 09-12Z. A weak warm front
moves through the area spreading a wintry mix of light snow with
some freezing rain possible generally south of I-90 starting as
early as 9Z near KEAT and about 12Z near KGEG vicinity.
Accumulations, if any, are expected to be very light. After the
front moves off Thursday morning...a moist boundary layer with
weak upslope flow will maintain the threat of MVFR ceilings over
the eastern TAF sites. /MJF


&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        23  34  31  38  34  42 /  10  70  20  40  90  40
Coeur d`Alene  23  34  32  40  34  41 /  10  70  30  50  90  70
Pullman        27  39  29  42  35  42 /  30  80  20  20  90  70
Lewiston       31  40  31  44  40  47 /  30  80  10  10  80  50
Colville       22  34  26  38  36  42 /   0  30  30  70 100  40
Sandpoint      20  34  30  40  34  41 /   0  50  50  70 100  60
Kellogg        22  34  31  38  34  38 /  10  80  40  50  90  90
Moses Lake     24  35  21  37  31  48 /  40  20  10  70 100  20
Wenatchee      26  39  28  35  33  46 /  40  20  10  80 100  20
Omak           22  36  27  36  31  43 /  10  20  10  80 100  20

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Air Stagnation Advisory until Noon PST Friday for Central
     Panhandle Mountains-Coeur d`Alene Area-Idaho Palouse-
     Northern Panhandle.

     Winter Storm Watch from Friday afternoon through Saturday
     afternoon for Central Panhandle Mountains-Northern
     Panhandle.

WA...Air Stagnation Advisory until Noon PST Friday for East Slopes
     Northern Cascades-Lower Garfield and Asotin Counties-Moses
     Lake Area-Northeast Mountains-Okanogan Highlands-Spokane
     Area-Upper Columbia Basin-Washington Palouse-Waterville
     Plateau-Wenatchee Area.

     Winter Storm Watch from Friday afternoon through Saturday
     afternoon for Northeast Mountains-Okanogan Highlands.

     Winter Storm Watch from Friday morning through late Friday night
     for East Slopes Northern Cascades.

&&

$$




000
FXUS66 KOTX 192344
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
344 PM PST WED NOV 19 2014

.SYNOPSIS...
A weak weather system will arrive late tonight into Thursday with
the potential for a light wintry mix of rain...snow...and freezing
rain. A stronger, wetter and windier weather system will arrive
Friday persisting into the weekend with heavy snow amounts
possible over the mountains. The weather pattern will remain
active through the middle of next week.

&&

.DISCUSSION...

Tonight and Tomorrow....The lingering very narrow and elongated
ridging nested between longwave trofs in the vicinity of the
Aleutian Islands and Eastern North America will continue to act as
a barrier toward effective passage of weather systems through the
region. Disturbances that have tried to penetrate this ridge
continue to be weakened and sheared apart as they move through the
ridge. The expectation similar weakening and splitting will occur
with weak wrapped up warm frontal band spiraling outward from a
low pressure system working east into this ridge that is expected
to pass through Eastern Washington and Northern Idaho late tonight
and Tomorrow. With this scenario in mind cloud cover ramps up
depicting the system passage. Additionally very light QPF and snow
amounts are assigned to any locations where the pops are high,
otherwise very low pops are assigned. The warm air advection
associated with the warm front gliding over the cool air we have
in place near the surface is likely to warm to as much as +3 C or
so in spots which would allow enough melting of any falling frozen
precipitation at the upper levels to refreeze at the surface in
some locations, generally south of I-90 so a mention of light
freezing precipitation in the form of either light freezing rain
or drizzle continues to be utilized. The emphasis on this system
being weak and not doing much in terms of mixing the atmosphere
and not producing much precipitation supports the extension of the
ongoing air stagnation advisory into Friday. /Pelatti


VALLEY RAIN AND HEAVY MOUNTAIN SNOW POSSIBLE EARLY THIS WEEKEND

Tonight through Saturday...The breakdown of the current ridge will
continue through this period with a second weak wave transiting
the region Thursday night...mainly impacting the north eastern
zones with light and largely non-accumulating snow showers or
flurries. This will be another shearing wave in a developing
northern branch flow above a deep trough over the Great Basin.
Very little and weak dynamic support as well as a westerly flow in
the mid levels will probably allow this system to skip the deep
basin where the main threat of freezing rain would be with
residual arctic air slow to scrub. As it stands the main threat
will be the potential for freezing drizzle Friday morning in the
Ritzville to Moses Lake area embedded in stubborn fog in this low
laying area. Otherwise for most locations outside of the Cascades
Friday will be a seasonably cool and cloudy day. With these weak
impulses doing little to impact the boundary layer the Air
Stagnation Advisory will remain valid through noon Friday with
re-evaluation with area AQ authorities on Friday morning.

The next Pacific storm system promises to be a much wetter and
more dynamic beast. The latest NAM...GFS and ECMWF models are in
pretty good agreement regarding the timing an character of this
storm...currently visible on satellite as a large baroclinic leaf
cloud shield way out near 160W south of the Aleutians. While the
details of the frontal complex are somewhat confused...in general
a strong moist warm front through much of Friday night will be
followed by a breezy and gusty cold front during the day on
Saturday. Rich moisture will efficiently lift over the warm front
which will develop Friday afternoon over the Cascades and envelop
the entire forecast area Friday night and Saturday morning.
Precipitation will likely be almost universal...and the storm
will be strong enough to decisively scour the basin out as snow
levels rise. While mainly rain is expected in the basin and
valleys of the Idaho Panhandle and northeast mountains...the
scouring process will be retarded in the Cascade valleys
particularly north of lake Chelan...and the high terrain of the
Waterville Plateau may also hold onto snow through much of the
night. Winter Storm Watches for this storm will be issued with the
afternoon package for the Cascades in general and the mountains of
northeast Washington and north Idaho above 4000 feet.

On Saturday the cold front will move through the Cascades early in
the day promoting a downslope shutdown of steady snow except for
slop-over off the crest. The front will cross the basin and bring
gusty winds...possibly 30 to 35 mph over the exposed terrain of
the eastern basin...and promote lingering snow showers piling into
the Idaho Panhandle mountains. Temperatures on Saturday will feel
mild after the last week with a well mixed air mass promoting
adiabatic compressional warming. /Fugazzi

Saturday night and Sunday: A shortwave trough will be pushing
through the region during this period. The ECMWF has sped up
to become more in line with the GFS on the timing of this
trough. The precip associated with this system will be mainly rain
for the Columbia Basin with a few flurries and snow for the
mountains. The mountain passes can expect to receive around 3
inches from this system. The northern mountains are expected to
receive at most an inch. Daytime temperatures will range from the
upper 30s to low 40s. The nighttime temperatures will range from
the upper 20s to low 30s. This could produce icy patches along the
roads during the night and early morning hours throughout the
Inland Northwest. /JDC

Monday through Wednesday: Model discrepancy is high out this far
in the forecast period. The ECMWF and GFS model runs show a more
active weather regime; whereas, the Canadian model shows a strong
ridge building in over the region with a return of drier and
stable conditions. The Canadian solution is the outlier and was
ignored. The difference between the GFS and ECMWF solutions is
that the GFS shows more of a zonal flow pattern setting up over
the region with stronger connections to a sub-tropical moisture
fetch. The ECMWF model continues with a more northwest oriented
flow pattern and takes the bulk of the moisture off of the Pacific
into Oregon, which then only clips the southern portion of the
forecast area. The GFS solution would result in a wetter and
milder scenario and a better chance for snow levels to rise above
valley floors. The ECMWF is colder and keeps a chance for valley
snow across much of the region. I decided to take more of a
compromise between these two solutions as each have equal merit.
I kept precip chances near to or above climatology with rain
across the basin and transitioning to snow across the northern
mountain valleys; confidence this far out in the forecast period
is low at this time due to model uncertainty. /SVH


&&

.AVIATION...
00Z TAFS: Ridge of high pressure keeps VFR conditions prevailing
for most aviation sites until about 09-12Z. A weak warm front
moves through the area spreading a wintry mix of light snow with
some freezing rain possible generally south of I-90 starting as
early as 9Z near KEAT and about 12Z near KGEG vicinity.
Accumulations, if any, are expected to be very light. After the
front moves off Thursday morning...a moist boundary layer with
weak upslope flow will maintain the threat of MVFR ceilings over
the eastern TAF sites. /MJF


&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        23  34  31  38  34  42 /  10  70  20  40  90  40
Coeur d`Alene  23  34  32  40  34  41 /  10  70  30  50  90  70
Pullman        27  39  29  42  35  42 /  30  80  20  20  90  70
Lewiston       31  40  31  44  40  47 /  30  80  10  10  80  50
Colville       22  34  26  38  36  42 /   0  30  30  70 100  40
Sandpoint      20  34  30  40  34  41 /   0  50  50  70 100  60
Kellogg        22  34  31  38  34  38 /  10  80  40  50  90  90
Moses Lake     24  35  21  37  31  48 /  40  20  10  70 100  20
Wenatchee      26  39  28  35  33  46 /  40  20  10  80 100  20
Omak           22  36  27  36  31  43 /  10  20  10  80 100  20

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Air Stagnation Advisory until Noon PST Friday for Central
     Panhandle Mountains-Coeur d`Alene Area-Idaho Palouse-
     Northern Panhandle.

     Winter Storm Watch from Friday afternoon through Saturday
     afternoon for Central Panhandle Mountains-Northern
     Panhandle.

WA...Air Stagnation Advisory until Noon PST Friday for East Slopes
     Northern Cascades-Lower Garfield and Asotin Counties-Moses
     Lake Area-Northeast Mountains-Okanogan Highlands-Spokane
     Area-Upper Columbia Basin-Washington Palouse-Waterville
     Plateau-Wenatchee Area.

     Winter Storm Watch from Friday afternoon through Saturday
     afternoon for Northeast Mountains-Okanogan Highlands.

     Winter Storm Watch from Friday morning through late Friday night
     for East Slopes Northern Cascades.

&&

$$





000
FXUS66 KSEW 192341
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
300 PM PST WED NOV 19 2014

.SYNOPSIS...A FRONT WILL BRING SOME RAIN TONIGHT. ANOTHER STRONGER
FRONT WILL IMPACT THE AREA ON FRIDAY AND FRIDAY NIGHT...BRINGING
RAIN...WIND...AND SNOW TO THE MOUNTAINS. ADDITIONAL WEATHER SYSTEMS
WILL ARRIVE EVERY DAY OR TWO THROUGH THE MIDDLE OF NEXT WEEK.

&&

.SHORT TERM...AS A FRONTAL SYSTEM ASSOCIATED WITH A SHORTWAVE TROUGH
MOVES INTO THE AREA...PRECIPITATION WILL SPREAD INTO WESTERN
WASHINGTON FROM SOUTHWEST TO NORTHEAST OVERNIGHT. THERE IS A CHANCE
OF FREEZING RAIN IN THE PASSES DUE TO EASTERLY FLOW BRINGING IN COLD
AIR AT LOWER LEVELS. THURSDAY MORNING THE PRECIPITATION WILL ALSO
TAPER OFF FROM SOUTHWEST TO NORTHEAST AS THE SYSTEM MOVES OUT OF THE
AREA. LINGERING SHOWERS ARE POSSIBLE ON THURSDAY AS THE AIR MASS
WILL BE A BIT UNSTABLE. THURSDAY NIGHT WILL BE FAIRLY DRY AS A WEAK
SURFACE LOW MOVES SOUTHEAST INTO NORTHERN CALIFORNIA.

ON FRIDAY AND FRIDAY NIGHT...A STRONGER COLD FRONT STEMMING FROM A
DEEP LOW IN THE GULF OF ALASKA WILL IMPACT THE AREA. WIND ADVISORY
LEVEL CONDITIONS ARE POSSIBLE FRIDAY ON THE COAST...AND FRIDAY NIGHT
IN THE NORTH INTERIOR WITH THIS SYSTEM. AREAS IN THE NORTH CASCADES
ABOVE 4000 FEET COULD ALSO SEE A GOOD AMOUNT OF SNOWFALL WITH THIS
SYSTEM.

ON SATURDAY A WEAK SHORTWAVE TROUGH WILL MOVE THROUGH WESTERN
WASHINGTON...LIKELY CONTINUING THE PRECIPITATION. JSMITH

&&

.LONG TERM...A COUPLE MORE SHORTWAVE TROUGHS WILL LIKELY IMPACT THE
AREA ON SUNDAY AND MONDAY...KEEPING BREEZY CONDITIONS AND
PRECIPITATION IN THE FORECAST. ON TUESDAY...MODELS ARE BEGINNING TO
AGREE THAT A PLUME OF MOISTURE CARRIED BY THE JET STREAM WILL IMPACT
THE NORTHWEST...AS PREDICTED BY THE ECMWF YESTERDAY. HOWEVER...A LOT
OF UNCERTAINTY EXISTS AS TO WHERE THIS MOISTURE WILL COME
ASHORE...THE ECMWF HAS IT HITTING OREGON WHEREAS THE GFS HAS IT
IMPACTING NORTHWEST WASHINGTON AND SOUTHWEST BC. THERE IS ALSO
UNCERTAINTY AS TO WHETHER IT WILL BE ACCOMPANIED BY A SURFACE LOW
PRESSURE SYSTEM.

MODELS DISAGREE ON ABOUT JUST ABOUT EVERYTHING WEDNESDAY AND
BEYOND...SO THE FORECAST IS VERY UNCERTAIN AT THIS POINT. JSMITH

&&

.HYDROLOGY...RIVER FLOODING IS NOT EXPECTED IN THE NEXT 7 DAYS.

&&

.AVIATION...A COLD FRONT OVER THE OREGON OFFSHORE WATERS WILL MOVE
NE ACROSS W WA TONIGHT...WITH RAIN SPREADING OVER SW WA THIS EVENING
AND THEN OVER THE N HALF OF W WA AFTER 06Z. CIGS BKN060-100 AHEAD OF
THE FRONT WILL LOWER TO MVFR LEVELS WITH AND BEHIND THE FRONT. LOCAL
IFR CIGS ARE POSSIBLE AFTER 12Z. FROPA ALONG A HQM-CLS LINE WILL BE
AROUND 08Z...THEN AT BLI AROUND 15Z. WEAK POST-FRONTAL WESTERLY FLOW
ALOFT WILL PREVAIL ON THURSDAY. A MOIST AIR MASS WILL KEEP CIGS
MAINLY IN THE 2000-5000 FOOT RANGE.

KSEA...GOOD VFR CONDITIONS WITH CIGS ABOVE BKN080-100 WILL CONTINUE
THROUGH ABOUT 05Z TONIGHT. RAIN FROM THE APPROACHING FRONT SHOULD
REACH THE TERMINAL AFTER 05Z...WITH CIGS GRADUALLY LOWERING TO MVFR
OVC015-025 AROUND 09Z...THEN CONTINUING THROUGH 18Z. SURFACE WINDS
ARE EXPECTED TO SHIFT FROM LIGHT N TO S 5-10 KT BY 02Z AND CONTINUE
THROUGH TONIGHT. KAM

&&

.MARINE...A COLD FRONT APPROACHING FROM THE SOUTHWEST WILL MOVE
ACROSS W WA LATE TONIGHT. MODERATE SOUTHEAST FLOW WILL BRING SMALL
CRAFT ADVISORY WINDS OVER MOST WATERS. POST FRONT SCA WINDS WILL
CONTINUE OVER MOST WATERS THROUGH THURSDAY MORNING.

A WEAKER TRAILING SYSTEM WILL HEAD TOWARD N CA ON THURSDAY AND WILL
HAVE NO IMPACT ON THE PACNW.

MODELS REMAIN FAIRLY CONSISTENT IN BRINGING A STRONGER FRONTAL
SYSTEM FROM THE WEST ON FRIDAY. HOWEVER THE WRF-GFS AND HIRES-ARW-W
HAVE BACKED OFF SLIGHTLY ON THE DURATION OF GALE FORCE WINDS...WITH
THE STRONGEST WINDS OVER THE COASTAL WATERS FRIDAY AFTERNOON...AND
OVER THE NORTH INTERIOR WATERS FRIDAY EVENING.

WESTERLY FLOW ALOFT OVER THE NE PACIFIC SATURDAY THROUGH MONDAY WILL
BRING SEVERAL WEAK SYSTEMS ACROSS THE AREA. KAM

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS EXCEPT THE CENTRAL STRAIT.
     GALE WATCH COAST FRIDAY.

&&

$$

WWW.WEATHER.GOV/SEATTLE

YOU CAN SEE AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML






000
FXUS66 KSEW 192341
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
300 PM PST WED NOV 19 2014

.SYNOPSIS...A FRONT WILL BRING SOME RAIN TONIGHT. ANOTHER STRONGER
FRONT WILL IMPACT THE AREA ON FRIDAY AND FRIDAY NIGHT...BRINGING
RAIN...WIND...AND SNOW TO THE MOUNTAINS. ADDITIONAL WEATHER SYSTEMS
WILL ARRIVE EVERY DAY OR TWO THROUGH THE MIDDLE OF NEXT WEEK.

&&

.SHORT TERM...AS A FRONTAL SYSTEM ASSOCIATED WITH A SHORTWAVE TROUGH
MOVES INTO THE AREA...PRECIPITATION WILL SPREAD INTO WESTERN
WASHINGTON FROM SOUTHWEST TO NORTHEAST OVERNIGHT. THERE IS A CHANCE
OF FREEZING RAIN IN THE PASSES DUE TO EASTERLY FLOW BRINGING IN COLD
AIR AT LOWER LEVELS. THURSDAY MORNING THE PRECIPITATION WILL ALSO
TAPER OFF FROM SOUTHWEST TO NORTHEAST AS THE SYSTEM MOVES OUT OF THE
AREA. LINGERING SHOWERS ARE POSSIBLE ON THURSDAY AS THE AIR MASS
WILL BE A BIT UNSTABLE. THURSDAY NIGHT WILL BE FAIRLY DRY AS A WEAK
SURFACE LOW MOVES SOUTHEAST INTO NORTHERN CALIFORNIA.

ON FRIDAY AND FRIDAY NIGHT...A STRONGER COLD FRONT STEMMING FROM A
DEEP LOW IN THE GULF OF ALASKA WILL IMPACT THE AREA. WIND ADVISORY
LEVEL CONDITIONS ARE POSSIBLE FRIDAY ON THE COAST...AND FRIDAY NIGHT
IN THE NORTH INTERIOR WITH THIS SYSTEM. AREAS IN THE NORTH CASCADES
ABOVE 4000 FEET COULD ALSO SEE A GOOD AMOUNT OF SNOWFALL WITH THIS
SYSTEM.

ON SATURDAY A WEAK SHORTWAVE TROUGH WILL MOVE THROUGH WESTERN
WASHINGTON...LIKELY CONTINUING THE PRECIPITATION. JSMITH

&&

.LONG TERM...A COUPLE MORE SHORTWAVE TROUGHS WILL LIKELY IMPACT THE
AREA ON SUNDAY AND MONDAY...KEEPING BREEZY CONDITIONS AND
PRECIPITATION IN THE FORECAST. ON TUESDAY...MODELS ARE BEGINNING TO
AGREE THAT A PLUME OF MOISTURE CARRIED BY THE JET STREAM WILL IMPACT
THE NORTHWEST...AS PREDICTED BY THE ECMWF YESTERDAY. HOWEVER...A LOT
OF UNCERTAINTY EXISTS AS TO WHERE THIS MOISTURE WILL COME
ASHORE...THE ECMWF HAS IT HITTING OREGON WHEREAS THE GFS HAS IT
IMPACTING NORTHWEST WASHINGTON AND SOUTHWEST BC. THERE IS ALSO
UNCERTAINTY AS TO WHETHER IT WILL BE ACCOMPANIED BY A SURFACE LOW
PRESSURE SYSTEM.

MODELS DISAGREE ON ABOUT JUST ABOUT EVERYTHING WEDNESDAY AND
BEYOND...SO THE FORECAST IS VERY UNCERTAIN AT THIS POINT. JSMITH

&&

.HYDROLOGY...RIVER FLOODING IS NOT EXPECTED IN THE NEXT 7 DAYS.

&&

.AVIATION...A COLD FRONT OVER THE OREGON OFFSHORE WATERS WILL MOVE
NE ACROSS W WA TONIGHT...WITH RAIN SPREADING OVER SW WA THIS EVENING
AND THEN OVER THE N HALF OF W WA AFTER 06Z. CIGS BKN060-100 AHEAD OF
THE FRONT WILL LOWER TO MVFR LEVELS WITH AND BEHIND THE FRONT. LOCAL
IFR CIGS ARE POSSIBLE AFTER 12Z. FROPA ALONG A HQM-CLS LINE WILL BE
AROUND 08Z...THEN AT BLI AROUND 15Z. WEAK POST-FRONTAL WESTERLY FLOW
ALOFT WILL PREVAIL ON THURSDAY. A MOIST AIR MASS WILL KEEP CIGS
MAINLY IN THE 2000-5000 FOOT RANGE.

KSEA...GOOD VFR CONDITIONS WITH CIGS ABOVE BKN080-100 WILL CONTINUE
THROUGH ABOUT 05Z TONIGHT. RAIN FROM THE APPROACHING FRONT SHOULD
REACH THE TERMINAL AFTER 05Z...WITH CIGS GRADUALLY LOWERING TO MVFR
OVC015-025 AROUND 09Z...THEN CONTINUING THROUGH 18Z. SURFACE WINDS
ARE EXPECTED TO SHIFT FROM LIGHT N TO S 5-10 KT BY 02Z AND CONTINUE
THROUGH TONIGHT. KAM

&&

.MARINE...A COLD FRONT APPROACHING FROM THE SOUTHWEST WILL MOVE
ACROSS W WA LATE TONIGHT. MODERATE SOUTHEAST FLOW WILL BRING SMALL
CRAFT ADVISORY WINDS OVER MOST WATERS. POST FRONT SCA WINDS WILL
CONTINUE OVER MOST WATERS THROUGH THURSDAY MORNING.

A WEAKER TRAILING SYSTEM WILL HEAD TOWARD N CA ON THURSDAY AND WILL
HAVE NO IMPACT ON THE PACNW.

MODELS REMAIN FAIRLY CONSISTENT IN BRINGING A STRONGER FRONTAL
SYSTEM FROM THE WEST ON FRIDAY. HOWEVER THE WRF-GFS AND HIRES-ARW-W
HAVE BACKED OFF SLIGHTLY ON THE DURATION OF GALE FORCE WINDS...WITH
THE STRONGEST WINDS OVER THE COASTAL WATERS FRIDAY AFTERNOON...AND
OVER THE NORTH INTERIOR WATERS FRIDAY EVENING.

WESTERLY FLOW ALOFT OVER THE NE PACIFIC SATURDAY THROUGH MONDAY WILL
BRING SEVERAL WEAK SYSTEMS ACROSS THE AREA. KAM

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS EXCEPT THE CENTRAL STRAIT.
     GALE WATCH COAST FRIDAY.

&&

$$

WWW.WEATHER.GOV/SEATTLE

YOU CAN SEE AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML






000
FXUS66 KSEW 192341
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
300 PM PST WED NOV 19 2014

.SYNOPSIS...A FRONT WILL BRING SOME RAIN TONIGHT. ANOTHER STRONGER
FRONT WILL IMPACT THE AREA ON FRIDAY AND FRIDAY NIGHT...BRINGING
RAIN...WIND...AND SNOW TO THE MOUNTAINS. ADDITIONAL WEATHER SYSTEMS
WILL ARRIVE EVERY DAY OR TWO THROUGH THE MIDDLE OF NEXT WEEK.

&&

.SHORT TERM...AS A FRONTAL SYSTEM ASSOCIATED WITH A SHORTWAVE TROUGH
MOVES INTO THE AREA...PRECIPITATION WILL SPREAD INTO WESTERN
WASHINGTON FROM SOUTHWEST TO NORTHEAST OVERNIGHT. THERE IS A CHANCE
OF FREEZING RAIN IN THE PASSES DUE TO EASTERLY FLOW BRINGING IN COLD
AIR AT LOWER LEVELS. THURSDAY MORNING THE PRECIPITATION WILL ALSO
TAPER OFF FROM SOUTHWEST TO NORTHEAST AS THE SYSTEM MOVES OUT OF THE
AREA. LINGERING SHOWERS ARE POSSIBLE ON THURSDAY AS THE AIR MASS
WILL BE A BIT UNSTABLE. THURSDAY NIGHT WILL BE FAIRLY DRY AS A WEAK
SURFACE LOW MOVES SOUTHEAST INTO NORTHERN CALIFORNIA.

ON FRIDAY AND FRIDAY NIGHT...A STRONGER COLD FRONT STEMMING FROM A
DEEP LOW IN THE GULF OF ALASKA WILL IMPACT THE AREA. WIND ADVISORY
LEVEL CONDITIONS ARE POSSIBLE FRIDAY ON THE COAST...AND FRIDAY NIGHT
IN THE NORTH INTERIOR WITH THIS SYSTEM. AREAS IN THE NORTH CASCADES
ABOVE 4000 FEET COULD ALSO SEE A GOOD AMOUNT OF SNOWFALL WITH THIS
SYSTEM.

ON SATURDAY A WEAK SHORTWAVE TROUGH WILL MOVE THROUGH WESTERN
WASHINGTON...LIKELY CONTINUING THE PRECIPITATION. JSMITH

&&

.LONG TERM...A COUPLE MORE SHORTWAVE TROUGHS WILL LIKELY IMPACT THE
AREA ON SUNDAY AND MONDAY...KEEPING BREEZY CONDITIONS AND
PRECIPITATION IN THE FORECAST. ON TUESDAY...MODELS ARE BEGINNING TO
AGREE THAT A PLUME OF MOISTURE CARRIED BY THE JET STREAM WILL IMPACT
THE NORTHWEST...AS PREDICTED BY THE ECMWF YESTERDAY. HOWEVER...A LOT
OF UNCERTAINTY EXISTS AS TO WHERE THIS MOISTURE WILL COME
ASHORE...THE ECMWF HAS IT HITTING OREGON WHEREAS THE GFS HAS IT
IMPACTING NORTHWEST WASHINGTON AND SOUTHWEST BC. THERE IS ALSO
UNCERTAINTY AS TO WHETHER IT WILL BE ACCOMPANIED BY A SURFACE LOW
PRESSURE SYSTEM.

MODELS DISAGREE ON ABOUT JUST ABOUT EVERYTHING WEDNESDAY AND
BEYOND...SO THE FORECAST IS VERY UNCERTAIN AT THIS POINT. JSMITH

&&

.HYDROLOGY...RIVER FLOODING IS NOT EXPECTED IN THE NEXT 7 DAYS.

&&

.AVIATION...A COLD FRONT OVER THE OREGON OFFSHORE WATERS WILL MOVE
NE ACROSS W WA TONIGHT...WITH RAIN SPREADING OVER SW WA THIS EVENING
AND THEN OVER THE N HALF OF W WA AFTER 06Z. CIGS BKN060-100 AHEAD OF
THE FRONT WILL LOWER TO MVFR LEVELS WITH AND BEHIND THE FRONT. LOCAL
IFR CIGS ARE POSSIBLE AFTER 12Z. FROPA ALONG A HQM-CLS LINE WILL BE
AROUND 08Z...THEN AT BLI AROUND 15Z. WEAK POST-FRONTAL WESTERLY FLOW
ALOFT WILL PREVAIL ON THURSDAY. A MOIST AIR MASS WILL KEEP CIGS
MAINLY IN THE 2000-5000 FOOT RANGE.

KSEA...GOOD VFR CONDITIONS WITH CIGS ABOVE BKN080-100 WILL CONTINUE
THROUGH ABOUT 05Z TONIGHT. RAIN FROM THE APPROACHING FRONT SHOULD
REACH THE TERMINAL AFTER 05Z...WITH CIGS GRADUALLY LOWERING TO MVFR
OVC015-025 AROUND 09Z...THEN CONTINUING THROUGH 18Z. SURFACE WINDS
ARE EXPECTED TO SHIFT FROM LIGHT N TO S 5-10 KT BY 02Z AND CONTINUE
THROUGH TONIGHT. KAM

&&

.MARINE...A COLD FRONT APPROACHING FROM THE SOUTHWEST WILL MOVE
ACROSS W WA LATE TONIGHT. MODERATE SOUTHEAST FLOW WILL BRING SMALL
CRAFT ADVISORY WINDS OVER MOST WATERS. POST FRONT SCA WINDS WILL
CONTINUE OVER MOST WATERS THROUGH THURSDAY MORNING.

A WEAKER TRAILING SYSTEM WILL HEAD TOWARD N CA ON THURSDAY AND WILL
HAVE NO IMPACT ON THE PACNW.

MODELS REMAIN FAIRLY CONSISTENT IN BRINGING A STRONGER FRONTAL
SYSTEM FROM THE WEST ON FRIDAY. HOWEVER THE WRF-GFS AND HIRES-ARW-W
HAVE BACKED OFF SLIGHTLY ON THE DURATION OF GALE FORCE WINDS...WITH
THE STRONGEST WINDS OVER THE COASTAL WATERS FRIDAY AFTERNOON...AND
OVER THE NORTH INTERIOR WATERS FRIDAY EVENING.

WESTERLY FLOW ALOFT OVER THE NE PACIFIC SATURDAY THROUGH MONDAY WILL
BRING SEVERAL WEAK SYSTEMS ACROSS THE AREA. KAM

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS EXCEPT THE CENTRAL STRAIT.
     GALE WATCH COAST FRIDAY.

&&

$$

WWW.WEATHER.GOV/SEATTLE

YOU CAN SEE AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML






000
FXUS66 KSEW 192341
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
300 PM PST WED NOV 19 2014

.SYNOPSIS...A FRONT WILL BRING SOME RAIN TONIGHT. ANOTHER STRONGER
FRONT WILL IMPACT THE AREA ON FRIDAY AND FRIDAY NIGHT...BRINGING
RAIN...WIND...AND SNOW TO THE MOUNTAINS. ADDITIONAL WEATHER SYSTEMS
WILL ARRIVE EVERY DAY OR TWO THROUGH THE MIDDLE OF NEXT WEEK.

&&

.SHORT TERM...AS A FRONTAL SYSTEM ASSOCIATED WITH A SHORTWAVE TROUGH
MOVES INTO THE AREA...PRECIPITATION WILL SPREAD INTO WESTERN
WASHINGTON FROM SOUTHWEST TO NORTHEAST OVERNIGHT. THERE IS A CHANCE
OF FREEZING RAIN IN THE PASSES DUE TO EASTERLY FLOW BRINGING IN COLD
AIR AT LOWER LEVELS. THURSDAY MORNING THE PRECIPITATION WILL ALSO
TAPER OFF FROM SOUTHWEST TO NORTHEAST AS THE SYSTEM MOVES OUT OF THE
AREA. LINGERING SHOWERS ARE POSSIBLE ON THURSDAY AS THE AIR MASS
WILL BE A BIT UNSTABLE. THURSDAY NIGHT WILL BE FAIRLY DRY AS A WEAK
SURFACE LOW MOVES SOUTHEAST INTO NORTHERN CALIFORNIA.

ON FRIDAY AND FRIDAY NIGHT...A STRONGER COLD FRONT STEMMING FROM A
DEEP LOW IN THE GULF OF ALASKA WILL IMPACT THE AREA. WIND ADVISORY
LEVEL CONDITIONS ARE POSSIBLE FRIDAY ON THE COAST...AND FRIDAY NIGHT
IN THE NORTH INTERIOR WITH THIS SYSTEM. AREAS IN THE NORTH CASCADES
ABOVE 4000 FEET COULD ALSO SEE A GOOD AMOUNT OF SNOWFALL WITH THIS
SYSTEM.

ON SATURDAY A WEAK SHORTWAVE TROUGH WILL MOVE THROUGH WESTERN
WASHINGTON...LIKELY CONTINUING THE PRECIPITATION. JSMITH

&&

.LONG TERM...A COUPLE MORE SHORTWAVE TROUGHS WILL LIKELY IMPACT THE
AREA ON SUNDAY AND MONDAY...KEEPING BREEZY CONDITIONS AND
PRECIPITATION IN THE FORECAST. ON TUESDAY...MODELS ARE BEGINNING TO
AGREE THAT A PLUME OF MOISTURE CARRIED BY THE JET STREAM WILL IMPACT
THE NORTHWEST...AS PREDICTED BY THE ECMWF YESTERDAY. HOWEVER...A LOT
OF UNCERTAINTY EXISTS AS TO WHERE THIS MOISTURE WILL COME
ASHORE...THE ECMWF HAS IT HITTING OREGON WHEREAS THE GFS HAS IT
IMPACTING NORTHWEST WASHINGTON AND SOUTHWEST BC. THERE IS ALSO
UNCERTAINTY AS TO WHETHER IT WILL BE ACCOMPANIED BY A SURFACE LOW
PRESSURE SYSTEM.

MODELS DISAGREE ON ABOUT JUST ABOUT EVERYTHING WEDNESDAY AND
BEYOND...SO THE FORECAST IS VERY UNCERTAIN AT THIS POINT. JSMITH

&&

.HYDROLOGY...RIVER FLOODING IS NOT EXPECTED IN THE NEXT 7 DAYS.

&&

.AVIATION...A COLD FRONT OVER THE OREGON OFFSHORE WATERS WILL MOVE
NE ACROSS W WA TONIGHT...WITH RAIN SPREADING OVER SW WA THIS EVENING
AND THEN OVER THE N HALF OF W WA AFTER 06Z. CIGS BKN060-100 AHEAD OF
THE FRONT WILL LOWER TO MVFR LEVELS WITH AND BEHIND THE FRONT. LOCAL
IFR CIGS ARE POSSIBLE AFTER 12Z. FROPA ALONG A HQM-CLS LINE WILL BE
AROUND 08Z...THEN AT BLI AROUND 15Z. WEAK POST-FRONTAL WESTERLY FLOW
ALOFT WILL PREVAIL ON THURSDAY. A MOIST AIR MASS WILL KEEP CIGS
MAINLY IN THE 2000-5000 FOOT RANGE.

KSEA...GOOD VFR CONDITIONS WITH CIGS ABOVE BKN080-100 WILL CONTINUE
THROUGH ABOUT 05Z TONIGHT. RAIN FROM THE APPROACHING FRONT SHOULD
REACH THE TERMINAL AFTER 05Z...WITH CIGS GRADUALLY LOWERING TO MVFR
OVC015-025 AROUND 09Z...THEN CONTINUING THROUGH 18Z. SURFACE WINDS
ARE EXPECTED TO SHIFT FROM LIGHT N TO S 5-10 KT BY 02Z AND CONTINUE
THROUGH TONIGHT. KAM

&&

.MARINE...A COLD FRONT APPROACHING FROM THE SOUTHWEST WILL MOVE
ACROSS W WA LATE TONIGHT. MODERATE SOUTHEAST FLOW WILL BRING SMALL
CRAFT ADVISORY WINDS OVER MOST WATERS. POST FRONT SCA WINDS WILL
CONTINUE OVER MOST WATERS THROUGH THURSDAY MORNING.

A WEAKER TRAILING SYSTEM WILL HEAD TOWARD N CA ON THURSDAY AND WILL
HAVE NO IMPACT ON THE PACNW.

MODELS REMAIN FAIRLY CONSISTENT IN BRINGING A STRONGER FRONTAL
SYSTEM FROM THE WEST ON FRIDAY. HOWEVER THE WRF-GFS AND HIRES-ARW-W
HAVE BACKED OFF SLIGHTLY ON THE DURATION OF GALE FORCE WINDS...WITH
THE STRONGEST WINDS OVER THE COASTAL WATERS FRIDAY AFTERNOON...AND
OVER THE NORTH INTERIOR WATERS FRIDAY EVENING.

WESTERLY FLOW ALOFT OVER THE NE PACIFIC SATURDAY THROUGH MONDAY WILL
BRING SEVERAL WEAK SYSTEMS ACROSS THE AREA. KAM

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS EXCEPT THE CENTRAL STRAIT.
     GALE WATCH COAST FRIDAY.

&&

$$

WWW.WEATHER.GOV/SEATTLE

YOU CAN SEE AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML






000
FXUS66 KPQR 192257
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
256 PM PST WED NOV 19 2014

.SYNOPSIS...RAIN WILL SPREAD ACROSS THE REGION THIS EVENING. THE
RAIN WILL MAINLY FALL AS FREEZING RAIN FOR THE COLUMBIA RIVER GORGE
BUT EXPECT TO SEE PERIODS OF SLEET AS WELL. TEMPERATURES WILL
MODERATE TO NEAR NORMAL BUT STILL REMAIN A BIT COOLER FOR AREAS
UNDER THE GORGE WIND INFLUENCE DURING THIS PERIOD. A STRONGER WET
AND WINDY STORM SYSTEM WILL ARRIVE FRIDAY. ADDITIONAL ROUNDS OF RAIN
WILL FALL OVER THE WEEKEND. LOWER SNOW LEVELS MAY BRING SIGNIFICANT
SNOW ACCUMULATIONS TO THE CASCADES PASSES OVER THE WEEKEND.
CURRENTLY...BEST TIMES TO CROSS THE OREGON PASSES APPEAR TO BE
FRIDAY AND SUNDAY MORNINGS.

&&

.SHORT TERM...TONIGHT THROUGH SATURDAY...MAIN ISSUE FOR TONIGHT
CONTINUES TO REVOLVE AROUND A FREEZING RAIN ADVISORY FOR THE GORGE
AND UPPER HOOD RIVER VALLEY. COLD POOL EAST OF THE CASCADES REMAINS
WELL ENTRENCHED. EASTERLY PRESSURE GRADIENT BETWEEN THE DALLES AND
TROUTDALE PEAKED AGAIN THIS MORNING THIS TIME AT 11.6 MB AND
CURRENTLY SITS AROUND 10 MB. WILL CONTINUE TO SEE THE GUSTY EAST
WINDS DRAW THAT COLD AIR THROUGH THE GORGE UNTIL GRADIENTS EASE
OVERNIGHT. THEY WILL STAY LIGHT EASTERLY HOWEVER SO HAVE SIGNIFICANT
DOUBTS THE GORGE...AND ESPECIALLY THE CENTRAL GORGE...WILL GET MUCH
WARMER OVER THE NEXT COUPLE DAYS. THE SYSTEM COMING IN TONIGHT STILL
LOOKS LIKE IT WILL HOLD TOGETHER ENOUGH TO BRING A NOTABLE THREAT OF
FREEZING RAIN AND/OR SLEET TO THE GORGE AREAS PRIMARILY EAST OF
SKAMANIA BUT EXPECT THE COLDER AIR WILL CONTINUE TO SEEP FURTHER
WEST AS WELL AND HAVE SOME IMPACTS CLOSER TO CORBETT. THE REST OF
THE REGION WEST OF THE CASCADES HAS WARMED UNDER THE ENCROACHING
MARITIME AIR MASS. THE AIR MASS EAST OF THE CREST REMAINS STAUNCHLY
CONTINENTAL WITH SUB-FREEZING TEMPERATURES EXCEEDING 3 KFT NEAR THE
DALLES. GIVEN THOSE FACTORS...MAY SEE MORE OF A SLEET STORM FOR THE
CENTRAL GORGE AND UPPER HOOD RIVER VALLEY EARLY THIS EVENING BEFORE
THE WARM AIR PUSHES OVER THE CASCADES. WILL THEN SEE FREEZING RAIN
DOMINATE LATER OVERNIGHT AND INTO THURSDAY MORNING. DECIDED TO KEEP
THE ADVISORY AS DOMINANT FREEZING RAIN BUT ALSO ADDED THE SLEET
MENTION FOR A FEW HOURS AT THE ONSET.

EXPECT THE PRIMARY THREAT TO BE OVER BY 12Z/4AM THURSDAY BUT DO
EXPECT FURTHER VERY LIGHT ACCUMULATIONS THROUGH A LARGE PART OF THE
DAY ACROSS THE ENTIRE AREA AS ANOTHER DEVELOPING SHORT WAVE WILL
LARGELY SLIDE SOUTH OF OUR AREA AND MAINLY INTO NORTHERN CALIFORNIA.
THERE WILL BE AREAS OF DEFORMATION OVER US TO PRODUCE MORE OF A
HYBRID STRATIFORM/SHOWER PRECIP SCENARIO. SNOW LEVELS WILL BEGIN
RISING RAPIDLY BY EARLY FRIDAY AS WARM FRONTAL RAIN UNDER MOIST
ZONAL PACIFIC FLOW SPREADS FROM WEST TO EAST. BY THEMSELVES...QPF
AMOUNTS ARE FAIRLY MODEST BUT DO APPROACH AN INCH ENDING SATURDAY
EVENING FOR THE VALLEYS AND A LITTLE OVER 2 INCHES FOR THE CASCADES
AND COAST RANGE. SNOW LEVELS STAY HIGH UNTIL THE COLD FRONT DOES
CROSS OVERNIGHT FRIDAY NIGHT. EXPECT TO SEE A FEW INCHES OF PASS
LEVEL ACCUMULATION LATER FRIDAY AND FRIDAY NIGHT JUST AHEAD OF THE
FRONT BUT THE MOISTURE EASES AFTER THE FRONT WITH SNOW LEVELS
FALLING TO AROUND 3000 FEET. HAVE ISSUED A SPECIAL WEATHER STATEMENT
FOR THE EXPECTED SNOW THIS WEEKEND.

AS MENTIONED PREVIOUSLY...DONT YET HAVE MUCH FAITH IN MODELED GORGE
TEMPERATURES RISING ABOVE FREEZING UNTIL PERHAPS LATER FRIDAY NIGHT
OR SATURDAY MORNING WHEN THE SURFACE PRESSURE GRADIENT TRULY BECOMES
WESTERLY. EXPERIENCE SHOWS MODELS ATTEMPT TO WARM UP THE GORGE BY
MIXING FROM ABOVE BUT THE COLDER DENSER AIR FROM EAST OF THE
CASCADES COMMONLY UNDERCUTS THAT MIXED LAYER UNTIL A SOLID WESTERLY
WIND PUSHES THROUGH THE LOWEST TERRAIN. AS SUCH WILL BE KEEPING A
CLOSE EYE ON WHAT ACTUALLY OCCURS TONIGHT AND EARLY TOMORROW. IF THE
HUNCH IS CORRECT...THE INCOMING SYSTEM FRIDAY COULD PRESENT A
SIGNIFICANT THREAT FOR AN ICE STORM COVERING AT LEAST THE CENTRAL
GORGE AND HOOD RIVER VALLEY...IF NOT THE WESTERN GORGE AS WELL. THE
ONE FACTOR IN FAVOR OF THE WARMING IS WE ARE STILL ON THE DOWNWARD
GLIDE SLOPE HEADING INTO CALENDAR WINTER. DECIDED TO HOLD OFF AND
TOW THE MODEL LINE REGARDING IMPROVING TEMPERATURES FOR NOW BUT
EXPECT THAT IF CONDITIONS REMAIN SUB-FREEZING NEAR AND EAST OF HOOD
RIVER...FRIDAY NIGHT COULD BE FAIRLY ICY. /JBONK

.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY. THE MORE WESTERLY OR
ZONAL FLOW THAT SETS UP LATE IN THE SHORT TERM PERIOD CONTINUES INTO
THE LONG TERM PERIOD...WITH OCCASIONAL RAIN AS DISTURBANCES MOVE
THROUGH. SOME RIDGING DEVELOPS IN THE NORTHEAST PACIFIC EARLY NEXT
WEEK...THOUGH THE MODELS VARY ON HOW MUCH. THE NORMALLY MORE
RELIABLE ECMWF MODEL HAS FLATTER RIDGING WITH MORE OF A DIRTY RIDGE
TYPE PATTERN AND DOES BRING SOME PRECIPITATION INTO THE FORECAST
AREA AT TIMES...WHILE THE OPERATIONAL GFS MODEL SHOWS MORE AMPLITUDE
DEVELOPING AND POSSIBLY SOME DRYING. THE PARALLEL VERSION OF THE GFS
MODEL IS A BIT MORE LIKE THE ECMWF. HAVE KEPT OUR CURRENT TRENDS
WHICH ARE MORE LIKE THE ECMWF AND THE PARALLEL GFS MODEL...THOUGH
CONFIDENCE IN ANY DETAILS ARE NOT VERY HIGH AT THIS POINT. TOLLESON
&&

.AVIATION...CURRENTLY WARM FRONTAL RAIN LOOKS TO BE NEAR KONP...SEEN
ON RADAR...PROGRESSING NORTHWARD. WARMER AIR MASS BEHIND FRONT
WILL LIKELY LOWER CIGS AT KEUG...SLE...AND COASTAL SITES TO MVFR
OR POSSIBLY EVEN IFR OVERNIGHT TONIGHT. DRY EASTERLY WINDS OUT OF
THE GORGE AT KTTD ARE STILL 25 KT GUSTING TO 35 KT THIS AFTERNOON.
THIS WILL PERSIST UNTIL AROUND 06Z THURSDAY WHEN THE FRONT MAKES
IT TO THE NORTH WILLAMETTE VALLEY. CHANCE OF RAIN AND MVFR
CONDITIONS PERSISTS THROUGH THURSDAY AFTERNOON...ESPECIALLY AFTER
12Z WHEN SOUTHERLY WINDS WEAKEN ACROSS THE AREA. AFTER THIS
TIME...CIGS AT LOCATIONS IN THE NORTHERN WILLAMETTE VALLEY COULD
DROP TO MVFR.


KPDX AND APPROACHES...VFR PREVAILING THROUGH EARLY THIS EVENING AS
DRY EASTERLY FLOW CONTINUES. AFTER ABOUT 12Z THURSDAY INCREASING
RAIN MAY BRING MVFR TO IFR CONDITIONS AFTER DRY EASTERLY WINDS OUT
OF THE GORGE BEGIN TO SUBSIDE AROUND 06Z.

-MCCOY

&&

.MARINE...WIND GENERALLY AROUND 15 TO 20 KTS GUSTS FREQUENTLY
REACHING 25 KTS AND WILL STAY ABOVE CRITERIA UNTIL EARLY THURSDAY.
SEAS 8 TO 10 FT CURRENTLY AND WILL CONTINUE TO BUILD TONIGHT TO
AROUND 13 FT BEFORE STARTING TO SUBSIDE AFTER MIDNIGHT. BY
THURSDAY MORNING SEAS WILL BE BACK DOWN TO AROUND 9 TO 10 FT.

STRONGER WEATHER SYSTEM WILL MOVE THROUGH ON FRIDAY. GALES ARE
VERY POSSIBLE ON FRIDAY AHEAD OF FRONTAL PASSAGE ACROSS OUR
WATERS. THURSDAY SEAS WILL HOVER AROUND 9 TO 10 FT BEFORE START
TO BUILD AGAIN EARLY FRIDAY. WAVE HEIGHTS WILL REACH THE MIDDLE
TEENS BY MID-DAY FRIDAY AND COULD EVEN GET INTO THE UPPER TEENS
ACROSS THE SOUTHERN WATERS WITH GALE FORCE WINDS POSSIBLE IN THIS
AREA. WINDS AND SEAS WILL SUBSIDE SATURDAY TO 10 TO 11 FT...AND SEAS
LOOK TO REMAIN ABOVE 10 FT THROUGH THE WEEKEND.

-MCCOY

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING RAIN ADVISORY FROM 6 PM THIS EVENING TO 4 AM PST
     THURSDAY FOR CENTRAL COLUMBIA RIVER GORGE-UPPER HOOD RIVER
     VALLEY-WESTERN COLUMBIA RIVER GORGE.

WA...FREEZING RAIN ADVISORY FROM 6 PM THIS EVENING TO 4 AM PST
     THURSDAY FOR CENTRAL COLUMBIA RIVER GORGE-WESTERN COLUMBIA
     RIVER GORGE.

PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 AM PST THURSDAY FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 AM PST THURSDAY
     FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

&&


$$

INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND

THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.




000
FXUS66 KPQR 192257
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
256 PM PST WED NOV 19 2014

.SYNOPSIS...RAIN WILL SPREAD ACROSS THE REGION THIS EVENING. THE
RAIN WILL MAINLY FALL AS FREEZING RAIN FOR THE COLUMBIA RIVER GORGE
BUT EXPECT TO SEE PERIODS OF SLEET AS WELL. TEMPERATURES WILL
MODERATE TO NEAR NORMAL BUT STILL REMAIN A BIT COOLER FOR AREAS
UNDER THE GORGE WIND INFLUENCE DURING THIS PERIOD. A STRONGER WET
AND WINDY STORM SYSTEM WILL ARRIVE FRIDAY. ADDITIONAL ROUNDS OF RAIN
WILL FALL OVER THE WEEKEND. LOWER SNOW LEVELS MAY BRING SIGNIFICANT
SNOW ACCUMULATIONS TO THE CASCADES PASSES OVER THE WEEKEND.
CURRENTLY...BEST TIMES TO CROSS THE OREGON PASSES APPEAR TO BE
FRIDAY AND SUNDAY MORNINGS.

&&

.SHORT TERM...TONIGHT THROUGH SATURDAY...MAIN ISSUE FOR TONIGHT
CONTINUES TO REVOLVE AROUND A FREEZING RAIN ADVISORY FOR THE GORGE
AND UPPER HOOD RIVER VALLEY. COLD POOL EAST OF THE CASCADES REMAINS
WELL ENTRENCHED. EASTERLY PRESSURE GRADIENT BETWEEN THE DALLES AND
TROUTDALE PEAKED AGAIN THIS MORNING THIS TIME AT 11.6 MB AND
CURRENTLY SITS AROUND 10 MB. WILL CONTINUE TO SEE THE GUSTY EAST
WINDS DRAW THAT COLD AIR THROUGH THE GORGE UNTIL GRADIENTS EASE
OVERNIGHT. THEY WILL STAY LIGHT EASTERLY HOWEVER SO HAVE SIGNIFICANT
DOUBTS THE GORGE...AND ESPECIALLY THE CENTRAL GORGE...WILL GET MUCH
WARMER OVER THE NEXT COUPLE DAYS. THE SYSTEM COMING IN TONIGHT STILL
LOOKS LIKE IT WILL HOLD TOGETHER ENOUGH TO BRING A NOTABLE THREAT OF
FREEZING RAIN AND/OR SLEET TO THE GORGE AREAS PRIMARILY EAST OF
SKAMANIA BUT EXPECT THE COLDER AIR WILL CONTINUE TO SEEP FURTHER
WEST AS WELL AND HAVE SOME IMPACTS CLOSER TO CORBETT. THE REST OF
THE REGION WEST OF THE CASCADES HAS WARMED UNDER THE ENCROACHING
MARITIME AIR MASS. THE AIR MASS EAST OF THE CREST REMAINS STAUNCHLY
CONTINENTAL WITH SUB-FREEZING TEMPERATURES EXCEEDING 3 KFT NEAR THE
DALLES. GIVEN THOSE FACTORS...MAY SEE MORE OF A SLEET STORM FOR THE
CENTRAL GORGE AND UPPER HOOD RIVER VALLEY EARLY THIS EVENING BEFORE
THE WARM AIR PUSHES OVER THE CASCADES. WILL THEN SEE FREEZING RAIN
DOMINATE LATER OVERNIGHT AND INTO THURSDAY MORNING. DECIDED TO KEEP
THE ADVISORY AS DOMINANT FREEZING RAIN BUT ALSO ADDED THE SLEET
MENTION FOR A FEW HOURS AT THE ONSET.

EXPECT THE PRIMARY THREAT TO BE OVER BY 12Z/4AM THURSDAY BUT DO
EXPECT FURTHER VERY LIGHT ACCUMULATIONS THROUGH A LARGE PART OF THE
DAY ACROSS THE ENTIRE AREA AS ANOTHER DEVELOPING SHORT WAVE WILL
LARGELY SLIDE SOUTH OF OUR AREA AND MAINLY INTO NORTHERN CALIFORNIA.
THERE WILL BE AREAS OF DEFORMATION OVER US TO PRODUCE MORE OF A
HYBRID STRATIFORM/SHOWER PRECIP SCENARIO. SNOW LEVELS WILL BEGIN
RISING RAPIDLY BY EARLY FRIDAY AS WARM FRONTAL RAIN UNDER MOIST
ZONAL PACIFIC FLOW SPREADS FROM WEST TO EAST. BY THEMSELVES...QPF
AMOUNTS ARE FAIRLY MODEST BUT DO APPROACH AN INCH ENDING SATURDAY
EVENING FOR THE VALLEYS AND A LITTLE OVER 2 INCHES FOR THE CASCADES
AND COAST RANGE. SNOW LEVELS STAY HIGH UNTIL THE COLD FRONT DOES
CROSS OVERNIGHT FRIDAY NIGHT. EXPECT TO SEE A FEW INCHES OF PASS
LEVEL ACCUMULATION LATER FRIDAY AND FRIDAY NIGHT JUST AHEAD OF THE
FRONT BUT THE MOISTURE EASES AFTER THE FRONT WITH SNOW LEVELS
FALLING TO AROUND 3000 FEET. HAVE ISSUED A SPECIAL WEATHER STATEMENT
FOR THE EXPECTED SNOW THIS WEEKEND.

AS MENTIONED PREVIOUSLY...DONT YET HAVE MUCH FAITH IN MODELED GORGE
TEMPERATURES RISING ABOVE FREEZING UNTIL PERHAPS LATER FRIDAY NIGHT
OR SATURDAY MORNING WHEN THE SURFACE PRESSURE GRADIENT TRULY BECOMES
WESTERLY. EXPERIENCE SHOWS MODELS ATTEMPT TO WARM UP THE GORGE BY
MIXING FROM ABOVE BUT THE COLDER DENSER AIR FROM EAST OF THE
CASCADES COMMONLY UNDERCUTS THAT MIXED LAYER UNTIL A SOLID WESTERLY
WIND PUSHES THROUGH THE LOWEST TERRAIN. AS SUCH WILL BE KEEPING A
CLOSE EYE ON WHAT ACTUALLY OCCURS TONIGHT AND EARLY TOMORROW. IF THE
HUNCH IS CORRECT...THE INCOMING SYSTEM FRIDAY COULD PRESENT A
SIGNIFICANT THREAT FOR AN ICE STORM COVERING AT LEAST THE CENTRAL
GORGE AND HOOD RIVER VALLEY...IF NOT THE WESTERN GORGE AS WELL. THE
ONE FACTOR IN FAVOR OF THE WARMING IS WE ARE STILL ON THE DOWNWARD
GLIDE SLOPE HEADING INTO CALENDAR WINTER. DECIDED TO HOLD OFF AND
TOW THE MODEL LINE REGARDING IMPROVING TEMPERATURES FOR NOW BUT
EXPECT THAT IF CONDITIONS REMAIN SUB-FREEZING NEAR AND EAST OF HOOD
RIVER...FRIDAY NIGHT COULD BE FAIRLY ICY. /JBONK

.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY. THE MORE WESTERLY OR
ZONAL FLOW THAT SETS UP LATE IN THE SHORT TERM PERIOD CONTINUES INTO
THE LONG TERM PERIOD...WITH OCCASIONAL RAIN AS DISTURBANCES MOVE
THROUGH. SOME RIDGING DEVELOPS IN THE NORTHEAST PACIFIC EARLY NEXT
WEEK...THOUGH THE MODELS VARY ON HOW MUCH. THE NORMALLY MORE
RELIABLE ECMWF MODEL HAS FLATTER RIDGING WITH MORE OF A DIRTY RIDGE
TYPE PATTERN AND DOES BRING SOME PRECIPITATION INTO THE FORECAST
AREA AT TIMES...WHILE THE OPERATIONAL GFS MODEL SHOWS MORE AMPLITUDE
DEVELOPING AND POSSIBLY SOME DRYING. THE PARALLEL VERSION OF THE GFS
MODEL IS A BIT MORE LIKE THE ECMWF. HAVE KEPT OUR CURRENT TRENDS
WHICH ARE MORE LIKE THE ECMWF AND THE PARALLEL GFS MODEL...THOUGH
CONFIDENCE IN ANY DETAILS ARE NOT VERY HIGH AT THIS POINT. TOLLESON
&&

.AVIATION...CURRENTLY WARM FRONTAL RAIN LOOKS TO BE NEAR KONP...SEEN
ON RADAR...PROGRESSING NORTHWARD. WARMER AIR MASS BEHIND FRONT
WILL LIKELY LOWER CIGS AT KEUG...SLE...AND COASTAL SITES TO MVFR
OR POSSIBLY EVEN IFR OVERNIGHT TONIGHT. DRY EASTERLY WINDS OUT OF
THE GORGE AT KTTD ARE STILL 25 KT GUSTING TO 35 KT THIS AFTERNOON.
THIS WILL PERSIST UNTIL AROUND 06Z THURSDAY WHEN THE FRONT MAKES
IT TO THE NORTH WILLAMETTE VALLEY. CHANCE OF RAIN AND MVFR
CONDITIONS PERSISTS THROUGH THURSDAY AFTERNOON...ESPECIALLY AFTER
12Z WHEN SOUTHERLY WINDS WEAKEN ACROSS THE AREA. AFTER THIS
TIME...CIGS AT LOCATIONS IN THE NORTHERN WILLAMETTE VALLEY COULD
DROP TO MVFR.


KPDX AND APPROACHES...VFR PREVAILING THROUGH EARLY THIS EVENING AS
DRY EASTERLY FLOW CONTINUES. AFTER ABOUT 12Z THURSDAY INCREASING
RAIN MAY BRING MVFR TO IFR CONDITIONS AFTER DRY EASTERLY WINDS OUT
OF THE GORGE BEGIN TO SUBSIDE AROUND 06Z.

-MCCOY

&&

.MARINE...WIND GENERALLY AROUND 15 TO 20 KTS GUSTS FREQUENTLY
REACHING 25 KTS AND WILL STAY ABOVE CRITERIA UNTIL EARLY THURSDAY.
SEAS 8 TO 10 FT CURRENTLY AND WILL CONTINUE TO BUILD TONIGHT TO
AROUND 13 FT BEFORE STARTING TO SUBSIDE AFTER MIDNIGHT. BY
THURSDAY MORNING SEAS WILL BE BACK DOWN TO AROUND 9 TO 10 FT.

STRONGER WEATHER SYSTEM WILL MOVE THROUGH ON FRIDAY. GALES ARE
VERY POSSIBLE ON FRIDAY AHEAD OF FRONTAL PASSAGE ACROSS OUR
WATERS. THURSDAY SEAS WILL HOVER AROUND 9 TO 10 FT BEFORE START
TO BUILD AGAIN EARLY FRIDAY. WAVE HEIGHTS WILL REACH THE MIDDLE
TEENS BY MID-DAY FRIDAY AND COULD EVEN GET INTO THE UPPER TEENS
ACROSS THE SOUTHERN WATERS WITH GALE FORCE WINDS POSSIBLE IN THIS
AREA. WINDS AND SEAS WILL SUBSIDE SATURDAY TO 10 TO 11 FT...AND SEAS
LOOK TO REMAIN ABOVE 10 FT THROUGH THE WEEKEND.

-MCCOY

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING RAIN ADVISORY FROM 6 PM THIS EVENING TO 4 AM PST
     THURSDAY FOR CENTRAL COLUMBIA RIVER GORGE-UPPER HOOD RIVER
     VALLEY-WESTERN COLUMBIA RIVER GORGE.

WA...FREEZING RAIN ADVISORY FROM 6 PM THIS EVENING TO 4 AM PST
     THURSDAY FOR CENTRAL COLUMBIA RIVER GORGE-WESTERN COLUMBIA
     RIVER GORGE.

PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 AM PST THURSDAY FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 AM PST THURSDAY
     FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

&&


$$

INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND

THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.




000
FXUS66 KPQR 192257
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
256 PM PST WED NOV 19 2014

.SYNOPSIS...RAIN WILL SPREAD ACROSS THE REGION THIS EVENING. THE
RAIN WILL MAINLY FALL AS FREEZING RAIN FOR THE COLUMBIA RIVER GORGE
BUT EXPECT TO SEE PERIODS OF SLEET AS WELL. TEMPERATURES WILL
MODERATE TO NEAR NORMAL BUT STILL REMAIN A BIT COOLER FOR AREAS
UNDER THE GORGE WIND INFLUENCE DURING THIS PERIOD. A STRONGER WET
AND WINDY STORM SYSTEM WILL ARRIVE FRIDAY. ADDITIONAL ROUNDS OF RAIN
WILL FALL OVER THE WEEKEND. LOWER SNOW LEVELS MAY BRING SIGNIFICANT
SNOW ACCUMULATIONS TO THE CASCADES PASSES OVER THE WEEKEND.
CURRENTLY...BEST TIMES TO CROSS THE OREGON PASSES APPEAR TO BE
FRIDAY AND SUNDAY MORNINGS.

&&

.SHORT TERM...TONIGHT THROUGH SATURDAY...MAIN ISSUE FOR TONIGHT
CONTINUES TO REVOLVE AROUND A FREEZING RAIN ADVISORY FOR THE GORGE
AND UPPER HOOD RIVER VALLEY. COLD POOL EAST OF THE CASCADES REMAINS
WELL ENTRENCHED. EASTERLY PRESSURE GRADIENT BETWEEN THE DALLES AND
TROUTDALE PEAKED AGAIN THIS MORNING THIS TIME AT 11.6 MB AND
CURRENTLY SITS AROUND 10 MB. WILL CONTINUE TO SEE THE GUSTY EAST
WINDS DRAW THAT COLD AIR THROUGH THE GORGE UNTIL GRADIENTS EASE
OVERNIGHT. THEY WILL STAY LIGHT EASTERLY HOWEVER SO HAVE SIGNIFICANT
DOUBTS THE GORGE...AND ESPECIALLY THE CENTRAL GORGE...WILL GET MUCH
WARMER OVER THE NEXT COUPLE DAYS. THE SYSTEM COMING IN TONIGHT STILL
LOOKS LIKE IT WILL HOLD TOGETHER ENOUGH TO BRING A NOTABLE THREAT OF
FREEZING RAIN AND/OR SLEET TO THE GORGE AREAS PRIMARILY EAST OF
SKAMANIA BUT EXPECT THE COLDER AIR WILL CONTINUE TO SEEP FURTHER
WEST AS WELL AND HAVE SOME IMPACTS CLOSER TO CORBETT. THE REST OF
THE REGION WEST OF THE CASCADES HAS WARMED UNDER THE ENCROACHING
MARITIME AIR MASS. THE AIR MASS EAST OF THE CREST REMAINS STAUNCHLY
CONTINENTAL WITH SUB-FREEZING TEMPERATURES EXCEEDING 3 KFT NEAR THE
DALLES. GIVEN THOSE FACTORS...MAY SEE MORE OF A SLEET STORM FOR THE
CENTRAL GORGE AND UPPER HOOD RIVER VALLEY EARLY THIS EVENING BEFORE
THE WARM AIR PUSHES OVER THE CASCADES. WILL THEN SEE FREEZING RAIN
DOMINATE LATER OVERNIGHT AND INTO THURSDAY MORNING. DECIDED TO KEEP
THE ADVISORY AS DOMINANT FREEZING RAIN BUT ALSO ADDED THE SLEET
MENTION FOR A FEW HOURS AT THE ONSET.

EXPECT THE PRIMARY THREAT TO BE OVER BY 12Z/4AM THURSDAY BUT DO
EXPECT FURTHER VERY LIGHT ACCUMULATIONS THROUGH A LARGE PART OF THE
DAY ACROSS THE ENTIRE AREA AS ANOTHER DEVELOPING SHORT WAVE WILL
LARGELY SLIDE SOUTH OF OUR AREA AND MAINLY INTO NORTHERN CALIFORNIA.
THERE WILL BE AREAS OF DEFORMATION OVER US TO PRODUCE MORE OF A
HYBRID STRATIFORM/SHOWER PRECIP SCENARIO. SNOW LEVELS WILL BEGIN
RISING RAPIDLY BY EARLY FRIDAY AS WARM FRONTAL RAIN UNDER MOIST
ZONAL PACIFIC FLOW SPREADS FROM WEST TO EAST. BY THEMSELVES...QPF
AMOUNTS ARE FAIRLY MODEST BUT DO APPROACH AN INCH ENDING SATURDAY
EVENING FOR THE VALLEYS AND A LITTLE OVER 2 INCHES FOR THE CASCADES
AND COAST RANGE. SNOW LEVELS STAY HIGH UNTIL THE COLD FRONT DOES
CROSS OVERNIGHT FRIDAY NIGHT. EXPECT TO SEE A FEW INCHES OF PASS
LEVEL ACCUMULATION LATER FRIDAY AND FRIDAY NIGHT JUST AHEAD OF THE
FRONT BUT THE MOISTURE EASES AFTER THE FRONT WITH SNOW LEVELS
FALLING TO AROUND 3000 FEET. HAVE ISSUED A SPECIAL WEATHER STATEMENT
FOR THE EXPECTED SNOW THIS WEEKEND.

AS MENTIONED PREVIOUSLY...DONT YET HAVE MUCH FAITH IN MODELED GORGE
TEMPERATURES RISING ABOVE FREEZING UNTIL PERHAPS LATER FRIDAY NIGHT
OR SATURDAY MORNING WHEN THE SURFACE PRESSURE GRADIENT TRULY BECOMES
WESTERLY. EXPERIENCE SHOWS MODELS ATTEMPT TO WARM UP THE GORGE BY
MIXING FROM ABOVE BUT THE COLDER DENSER AIR FROM EAST OF THE
CASCADES COMMONLY UNDERCUTS THAT MIXED LAYER UNTIL A SOLID WESTERLY
WIND PUSHES THROUGH THE LOWEST TERRAIN. AS SUCH WILL BE KEEPING A
CLOSE EYE ON WHAT ACTUALLY OCCURS TONIGHT AND EARLY TOMORROW. IF THE
HUNCH IS CORRECT...THE INCOMING SYSTEM FRIDAY COULD PRESENT A
SIGNIFICANT THREAT FOR AN ICE STORM COVERING AT LEAST THE CENTRAL
GORGE AND HOOD RIVER VALLEY...IF NOT THE WESTERN GORGE AS WELL. THE
ONE FACTOR IN FAVOR OF THE WARMING IS WE ARE STILL ON THE DOWNWARD
GLIDE SLOPE HEADING INTO CALENDAR WINTER. DECIDED TO HOLD OFF AND
TOW THE MODEL LINE REGARDING IMPROVING TEMPERATURES FOR NOW BUT
EXPECT THAT IF CONDITIONS REMAIN SUB-FREEZING NEAR AND EAST OF HOOD
RIVER...FRIDAY NIGHT COULD BE FAIRLY ICY. /JBONK

.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY. THE MORE WESTERLY OR
ZONAL FLOW THAT SETS UP LATE IN THE SHORT TERM PERIOD CONTINUES INTO
THE LONG TERM PERIOD...WITH OCCASIONAL RAIN AS DISTURBANCES MOVE
THROUGH. SOME RIDGING DEVELOPS IN THE NORTHEAST PACIFIC EARLY NEXT
WEEK...THOUGH THE MODELS VARY ON HOW MUCH. THE NORMALLY MORE
RELIABLE ECMWF MODEL HAS FLATTER RIDGING WITH MORE OF A DIRTY RIDGE
TYPE PATTERN AND DOES BRING SOME PRECIPITATION INTO THE FORECAST
AREA AT TIMES...WHILE THE OPERATIONAL GFS MODEL SHOWS MORE AMPLITUDE
DEVELOPING AND POSSIBLY SOME DRYING. THE PARALLEL VERSION OF THE GFS
MODEL IS A BIT MORE LIKE THE ECMWF. HAVE KEPT OUR CURRENT TRENDS
WHICH ARE MORE LIKE THE ECMWF AND THE PARALLEL GFS MODEL...THOUGH
CONFIDENCE IN ANY DETAILS ARE NOT VERY HIGH AT THIS POINT. TOLLESON
&&

.AVIATION...CURRENTLY WARM FRONTAL RAIN LOOKS TO BE NEAR KONP...SEEN
ON RADAR...PROGRESSING NORTHWARD. WARMER AIR MASS BEHIND FRONT
WILL LIKELY LOWER CIGS AT KEUG...SLE...AND COASTAL SITES TO MVFR
OR POSSIBLY EVEN IFR OVERNIGHT TONIGHT. DRY EASTERLY WINDS OUT OF
THE GORGE AT KTTD ARE STILL 25 KT GUSTING TO 35 KT THIS AFTERNOON.
THIS WILL PERSIST UNTIL AROUND 06Z THURSDAY WHEN THE FRONT MAKES
IT TO THE NORTH WILLAMETTE VALLEY. CHANCE OF RAIN AND MVFR
CONDITIONS PERSISTS THROUGH THURSDAY AFTERNOON...ESPECIALLY AFTER
12Z WHEN SOUTHERLY WINDS WEAKEN ACROSS THE AREA. AFTER THIS
TIME...CIGS AT LOCATIONS IN THE NORTHERN WILLAMETTE VALLEY COULD
DROP TO MVFR.


KPDX AND APPROACHES...VFR PREVAILING THROUGH EARLY THIS EVENING AS
DRY EASTERLY FLOW CONTINUES. AFTER ABOUT 12Z THURSDAY INCREASING
RAIN MAY BRING MVFR TO IFR CONDITIONS AFTER DRY EASTERLY WINDS OUT
OF THE GORGE BEGIN TO SUBSIDE AROUND 06Z.

-MCCOY

&&

.MARINE...WIND GENERALLY AROUND 15 TO 20 KTS GUSTS FREQUENTLY
REACHING 25 KTS AND WILL STAY ABOVE CRITERIA UNTIL EARLY THURSDAY.
SEAS 8 TO 10 FT CURRENTLY AND WILL CONTINUE TO BUILD TONIGHT TO
AROUND 13 FT BEFORE STARTING TO SUBSIDE AFTER MIDNIGHT. BY
THURSDAY MORNING SEAS WILL BE BACK DOWN TO AROUND 9 TO 10 FT.

STRONGER WEATHER SYSTEM WILL MOVE THROUGH ON FRIDAY. GALES ARE
VERY POSSIBLE ON FRIDAY AHEAD OF FRONTAL PASSAGE ACROSS OUR
WATERS. THURSDAY SEAS WILL HOVER AROUND 9 TO 10 FT BEFORE START
TO BUILD AGAIN EARLY FRIDAY. WAVE HEIGHTS WILL REACH THE MIDDLE
TEENS BY MID-DAY FRIDAY AND COULD EVEN GET INTO THE UPPER TEENS
ACROSS THE SOUTHERN WATERS WITH GALE FORCE WINDS POSSIBLE IN THIS
AREA. WINDS AND SEAS WILL SUBSIDE SATURDAY TO 10 TO 11 FT...AND SEAS
LOOK TO REMAIN ABOVE 10 FT THROUGH THE WEEKEND.

-MCCOY

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING RAIN ADVISORY FROM 6 PM THIS EVENING TO 4 AM PST
     THURSDAY FOR CENTRAL COLUMBIA RIVER GORGE-UPPER HOOD RIVER
     VALLEY-WESTERN COLUMBIA RIVER GORGE.

WA...FREEZING RAIN ADVISORY FROM 6 PM THIS EVENING TO 4 AM PST
     THURSDAY FOR CENTRAL COLUMBIA RIVER GORGE-WESTERN COLUMBIA
     RIVER GORGE.

PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 AM PST THURSDAY FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 AM PST THURSDAY
     FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

&&


$$

INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND

THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.




000
FXUS66 KPQR 192257
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
256 PM PST WED NOV 19 2014

.SYNOPSIS...RAIN WILL SPREAD ACROSS THE REGION THIS EVENING. THE
RAIN WILL MAINLY FALL AS FREEZING RAIN FOR THE COLUMBIA RIVER GORGE
BUT EXPECT TO SEE PERIODS OF SLEET AS WELL. TEMPERATURES WILL
MODERATE TO NEAR NORMAL BUT STILL REMAIN A BIT COOLER FOR AREAS
UNDER THE GORGE WIND INFLUENCE DURING THIS PERIOD. A STRONGER WET
AND WINDY STORM SYSTEM WILL ARRIVE FRIDAY. ADDITIONAL ROUNDS OF RAIN
WILL FALL OVER THE WEEKEND. LOWER SNOW LEVELS MAY BRING SIGNIFICANT
SNOW ACCUMULATIONS TO THE CASCADES PASSES OVER THE WEEKEND.
CURRENTLY...BEST TIMES TO CROSS THE OREGON PASSES APPEAR TO BE
FRIDAY AND SUNDAY MORNINGS.

&&

.SHORT TERM...TONIGHT THROUGH SATURDAY...MAIN ISSUE FOR TONIGHT
CONTINUES TO REVOLVE AROUND A FREEZING RAIN ADVISORY FOR THE GORGE
AND UPPER HOOD RIVER VALLEY. COLD POOL EAST OF THE CASCADES REMAINS
WELL ENTRENCHED. EASTERLY PRESSURE GRADIENT BETWEEN THE DALLES AND
TROUTDALE PEAKED AGAIN THIS MORNING THIS TIME AT 11.6 MB AND
CURRENTLY SITS AROUND 10 MB. WILL CONTINUE TO SEE THE GUSTY EAST
WINDS DRAW THAT COLD AIR THROUGH THE GORGE UNTIL GRADIENTS EASE
OVERNIGHT. THEY WILL STAY LIGHT EASTERLY HOWEVER SO HAVE SIGNIFICANT
DOUBTS THE GORGE...AND ESPECIALLY THE CENTRAL GORGE...WILL GET MUCH
WARMER OVER THE NEXT COUPLE DAYS. THE SYSTEM COMING IN TONIGHT STILL
LOOKS LIKE IT WILL HOLD TOGETHER ENOUGH TO BRING A NOTABLE THREAT OF
FREEZING RAIN AND/OR SLEET TO THE GORGE AREAS PRIMARILY EAST OF
SKAMANIA BUT EXPECT THE COLDER AIR WILL CONTINUE TO SEEP FURTHER
WEST AS WELL AND HAVE SOME IMPACTS CLOSER TO CORBETT. THE REST OF
THE REGION WEST OF THE CASCADES HAS WARMED UNDER THE ENCROACHING
MARITIME AIR MASS. THE AIR MASS EAST OF THE CREST REMAINS STAUNCHLY
CONTINENTAL WITH SUB-FREEZING TEMPERATURES EXCEEDING 3 KFT NEAR THE
DALLES. GIVEN THOSE FACTORS...MAY SEE MORE OF A SLEET STORM FOR THE
CENTRAL GORGE AND UPPER HOOD RIVER VALLEY EARLY THIS EVENING BEFORE
THE WARM AIR PUSHES OVER THE CASCADES. WILL THEN SEE FREEZING RAIN
DOMINATE LATER OVERNIGHT AND INTO THURSDAY MORNING. DECIDED TO KEEP
THE ADVISORY AS DOMINANT FREEZING RAIN BUT ALSO ADDED THE SLEET
MENTION FOR A FEW HOURS AT THE ONSET.

EXPECT THE PRIMARY THREAT TO BE OVER BY 12Z/4AM THURSDAY BUT DO
EXPECT FURTHER VERY LIGHT ACCUMULATIONS THROUGH A LARGE PART OF THE
DAY ACROSS THE ENTIRE AREA AS ANOTHER DEVELOPING SHORT WAVE WILL
LARGELY SLIDE SOUTH OF OUR AREA AND MAINLY INTO NORTHERN CALIFORNIA.
THERE WILL BE AREAS OF DEFORMATION OVER US TO PRODUCE MORE OF A
HYBRID STRATIFORM/SHOWER PRECIP SCENARIO. SNOW LEVELS WILL BEGIN
RISING RAPIDLY BY EARLY FRIDAY AS WARM FRONTAL RAIN UNDER MOIST
ZONAL PACIFIC FLOW SPREADS FROM WEST TO EAST. BY THEMSELVES...QPF
AMOUNTS ARE FAIRLY MODEST BUT DO APPROACH AN INCH ENDING SATURDAY
EVENING FOR THE VALLEYS AND A LITTLE OVER 2 INCHES FOR THE CASCADES
AND COAST RANGE. SNOW LEVELS STAY HIGH UNTIL THE COLD FRONT DOES
CROSS OVERNIGHT FRIDAY NIGHT. EXPECT TO SEE A FEW INCHES OF PASS
LEVEL ACCUMULATION LATER FRIDAY AND FRIDAY NIGHT JUST AHEAD OF THE
FRONT BUT THE MOISTURE EASES AFTER THE FRONT WITH SNOW LEVELS
FALLING TO AROUND 3000 FEET. HAVE ISSUED A SPECIAL WEATHER STATEMENT
FOR THE EXPECTED SNOW THIS WEEKEND.

AS MENTIONED PREVIOUSLY...DONT YET HAVE MUCH FAITH IN MODELED GORGE
TEMPERATURES RISING ABOVE FREEZING UNTIL PERHAPS LATER FRIDAY NIGHT
OR SATURDAY MORNING WHEN THE SURFACE PRESSURE GRADIENT TRULY BECOMES
WESTERLY. EXPERIENCE SHOWS MODELS ATTEMPT TO WARM UP THE GORGE BY
MIXING FROM ABOVE BUT THE COLDER DENSER AIR FROM EAST OF THE
CASCADES COMMONLY UNDERCUTS THAT MIXED LAYER UNTIL A SOLID WESTERLY
WIND PUSHES THROUGH THE LOWEST TERRAIN. AS SUCH WILL BE KEEPING A
CLOSE EYE ON WHAT ACTUALLY OCCURS TONIGHT AND EARLY TOMORROW. IF THE
HUNCH IS CORRECT...THE INCOMING SYSTEM FRIDAY COULD PRESENT A
SIGNIFICANT THREAT FOR AN ICE STORM COVERING AT LEAST THE CENTRAL
GORGE AND HOOD RIVER VALLEY...IF NOT THE WESTERN GORGE AS WELL. THE
ONE FACTOR IN FAVOR OF THE WARMING IS WE ARE STILL ON THE DOWNWARD
GLIDE SLOPE HEADING INTO CALENDAR WINTER. DECIDED TO HOLD OFF AND
TOW THE MODEL LINE REGARDING IMPROVING TEMPERATURES FOR NOW BUT
EXPECT THAT IF CONDITIONS REMAIN SUB-FREEZING NEAR AND EAST OF HOOD
RIVER...FRIDAY NIGHT COULD BE FAIRLY ICY. /JBONK

.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY. THE MORE WESTERLY OR
ZONAL FLOW THAT SETS UP LATE IN THE SHORT TERM PERIOD CONTINUES INTO
THE LONG TERM PERIOD...WITH OCCASIONAL RAIN AS DISTURBANCES MOVE
THROUGH. SOME RIDGING DEVELOPS IN THE NORTHEAST PACIFIC EARLY NEXT
WEEK...THOUGH THE MODELS VARY ON HOW MUCH. THE NORMALLY MORE
RELIABLE ECMWF MODEL HAS FLATTER RIDGING WITH MORE OF A DIRTY RIDGE
TYPE PATTERN AND DOES BRING SOME PRECIPITATION INTO THE FORECAST
AREA AT TIMES...WHILE THE OPERATIONAL GFS MODEL SHOWS MORE AMPLITUDE
DEVELOPING AND POSSIBLY SOME DRYING. THE PARALLEL VERSION OF THE GFS
MODEL IS A BIT MORE LIKE THE ECMWF. HAVE KEPT OUR CURRENT TRENDS
WHICH ARE MORE LIKE THE ECMWF AND THE PARALLEL GFS MODEL...THOUGH
CONFIDENCE IN ANY DETAILS ARE NOT VERY HIGH AT THIS POINT. TOLLESON
&&

.AVIATION...CURRENTLY WARM FRONTAL RAIN LOOKS TO BE NEAR KONP...SEEN
ON RADAR...PROGRESSING NORTHWARD. WARMER AIR MASS BEHIND FRONT
WILL LIKELY LOWER CIGS AT KEUG...SLE...AND COASTAL SITES TO MVFR
OR POSSIBLY EVEN IFR OVERNIGHT TONIGHT. DRY EASTERLY WINDS OUT OF
THE GORGE AT KTTD ARE STILL 25 KT GUSTING TO 35 KT THIS AFTERNOON.
THIS WILL PERSIST UNTIL AROUND 06Z THURSDAY WHEN THE FRONT MAKES
IT TO THE NORTH WILLAMETTE VALLEY. CHANCE OF RAIN AND MVFR
CONDITIONS PERSISTS THROUGH THURSDAY AFTERNOON...ESPECIALLY AFTER
12Z WHEN SOUTHERLY WINDS WEAKEN ACROSS THE AREA. AFTER THIS
TIME...CIGS AT LOCATIONS IN THE NORTHERN WILLAMETTE VALLEY COULD
DROP TO MVFR.


KPDX AND APPROACHES...VFR PREVAILING THROUGH EARLY THIS EVENING AS
DRY EASTERLY FLOW CONTINUES. AFTER ABOUT 12Z THURSDAY INCREASING
RAIN MAY BRING MVFR TO IFR CONDITIONS AFTER DRY EASTERLY WINDS OUT
OF THE GORGE BEGIN TO SUBSIDE AROUND 06Z.

-MCCOY

&&

.MARINE...WIND GENERALLY AROUND 15 TO 20 KTS GUSTS FREQUENTLY
REACHING 25 KTS AND WILL STAY ABOVE CRITERIA UNTIL EARLY THURSDAY.
SEAS 8 TO 10 FT CURRENTLY AND WILL CONTINUE TO BUILD TONIGHT TO
AROUND 13 FT BEFORE STARTING TO SUBSIDE AFTER MIDNIGHT. BY
THURSDAY MORNING SEAS WILL BE BACK DOWN TO AROUND 9 TO 10 FT.

STRONGER WEATHER SYSTEM WILL MOVE THROUGH ON FRIDAY. GALES ARE
VERY POSSIBLE ON FRIDAY AHEAD OF FRONTAL PASSAGE ACROSS OUR
WATERS. THURSDAY SEAS WILL HOVER AROUND 9 TO 10 FT BEFORE START
TO BUILD AGAIN EARLY FRIDAY. WAVE HEIGHTS WILL REACH THE MIDDLE
TEENS BY MID-DAY FRIDAY AND COULD EVEN GET INTO THE UPPER TEENS
ACROSS THE SOUTHERN WATERS WITH GALE FORCE WINDS POSSIBLE IN THIS
AREA. WINDS AND SEAS WILL SUBSIDE SATURDAY TO 10 TO 11 FT...AND SEAS
LOOK TO REMAIN ABOVE 10 FT THROUGH THE WEEKEND.

-MCCOY

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING RAIN ADVISORY FROM 6 PM THIS EVENING TO 4 AM PST
     THURSDAY FOR CENTRAL COLUMBIA RIVER GORGE-UPPER HOOD RIVER
     VALLEY-WESTERN COLUMBIA RIVER GORGE.

WA...FREEZING RAIN ADVISORY FROM 6 PM THIS EVENING TO 4 AM PST
     THURSDAY FOR CENTRAL COLUMBIA RIVER GORGE-WESTERN COLUMBIA
     RIVER GORGE.

PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 AM PST THURSDAY FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 AM PST THURSDAY
     FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

&&


$$

INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND

THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.




000
FXUS66 KOTX 192226
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
226 PM PST WED NOV 19 2014

.SYNOPSIS...
A weak weather system will arrive late tonight into Thursday with
the potential for a light wintry mix of rain...snow...and freezing
rain. A stronger, wetter and windier weather system will arrive
Friday persisting into the weekend with heavy snow amounts
possible over the mountains. The weather pattern will remain
active through the middle of next week.

&&

.DISCUSSION...

Tonight and Tomorrow....The lingering very narrow and elongated
ridging nested between longwave trofs in the vicinity of the
Aleutian Islands and Eastern North America will continue to act as
a barrier toward effective passage of weather systems through the
region. Disturbances that have tried to penetrate this ridge
continue to be weakened and sheared apart as they move through the
ridge. The expectation similar weakening and splitting will occur
with weak wrapped up warm frontal band spiraling outward from a
low pressure system working east into this ridge that is expected
to pass through Eastern Washington and Northern Idaho late tonight
and Tomorrow. With this scenario in mind cloud cover ramps up
depicting the system passage. Additionally very light QPF and snow
amounts are assigned to any locations where the pops are high,
otherwise very low pops are assigned. The warm air advection
associated with the warm front gliding over the cool air we have
in place near the surface is likely to warm to as much as +3 C or
so in spots which would allow enough melting of any falling frozen
precipitation at the upper levels to refreeze at the surface in
some locations, generally south of I-90 so a mention of light
freezing precipitation in the form of either light freezing rain
or drizzle continues to be utilized. The emphasis on this system
being weak and not doing much in terms of mixing the atmosphere
and not producing much precipitation supports the extension of the
ongoing air stagnation advisory into Friday. /Pelatti


VALLEY RAIN AND HEAVY MOUNTAIN SNOW POSSIBLE EARLY THIS WEEKEND

Tonight through Saturday...The breakdown of the current ridge will
continue through this period with a second weak wave transiting
the region Thursday night...mainly impacting the north eastern
zones with light and largely non-accumulating snow showers or
flurries. This will be another shearing wave in a developing
northern branch flow above a deep trough over the Great Basin.
Very little and weak dynamic support as well as a westerly flow in
the mid levels will probably allow this system to skip the deep
basin where the main threat of freezing rain would be with
residual arctic air slow to scrub. As it stands the main threat
will be the potential for freezing drizzle Friday morning in the
Ritzville to Moses Lake area embedded in stubborn fog in this low
laying area. Otherwise for most locations outside of the Cascades
Friday will be a seasonably cool and cloudy day. With these weak
impulses doing little to impact the boundary layer the Air
Stagnation Advisory will remain valid through noon Friday with
re-evaluation with area AQ authorities on Friday morning.

The next Pacific storm system promises to be a much wetter and
more dynamic beast. The latest NAM...GFS and ECMWF models are in
pretty good agreement regarding the timing an character of this
storm...currently visible on satellite as a large baroclinic leaf
cloud shield way out near 160W south of the Aleutians. While the
details of the frontal complex are somewhat confused...in general
a strong moist warm front through much of Friday night will be
followed by a breezy and gusty cold front during the day on
Saturday. Rich moisture will efficiently lift over the warm front
which will develop Friday afternoon over the Cascades and envelop
the entire forecast area Friday night and Saturday morning.
Precipitation will likely be almost universal...and the storm
will be strong enough to decisively scour the basin out as snow
levels rise. While mainly rain is expected in the basin and
valleys of the Idaho Panhandle and northeast mountains...the
scouring process will be retarded in the Cascade valleys
particularly north of lake Chelan...and the high terrain of the
Waterville Plateau may also hold onto snow through much of the
night. Winter Storm Watches for this storm will be issued with the
afternoon package for the Cascades in general and the mountains of
northeast Washington and north Idaho above 4000 feet.

On Saturday the cold front will move through the Cascades early in
the day promoting a downslope shutdown of steady snow except for
slop-over off the crest. The front will cross the basin and bring
gusty winds...possibly 30 to 35 mph over the exposed terrain of
the eastern basin...and promote lingering snow showers piling into
the Idaho Panhandle mountains. Temperatures on Saturday will feel
mild after the last week with a well mixed air mass promoting
adiabatic compressional warming. /Fugazzi

Saturday night and Sunday: A shortwave trough will be pushing
through the region during this period. The ECMWF has sped up
to become more in line with the GFS on the timing of this
trough. The precip associated with this system will be mainly rain
for the Columbia Basin with a few flurries and snow for the
mountains. The mountain passes can expect to receive around 3
inches from this system. The northern mountains are expected to
receive at most an inch. Daytime temperatures will range from the
upper 30s to low 40s. The nighttime temperatures will range from
the upper 20s to low 30s. This could produce icy patches along the
roads during the night and early morning hours throughout the
Inland Northwest. /JDC

Monday through Wednesday: Model discrepancy is high out this far
in the forecast period. The ECMWF and GFS model runs show a more
active weather regime; whereas, the Canadian model shows a strong
ridge building in over the region with a return of drier and
stable conditions. The Canadian solution is the outlier and was
ignored. The difference between the GFS and ECMWF solutions is
that the GFS shows more of a zonal flow pattern setting up over
the region with stronger connections to a sub-tropical moisture
fetch. The ECMWF model continues with a more northwest oriented
flow pattern and takes the bulk of the moisture off of the Pacific
into Oregon, which then only clips the southern portion of the
forecast area. The GFS solution would result in a wetter and
milder scenario and a better chance for snow levels to rise above
valley floors. The ECMWF is colder and keeps a chance for valley
snow across much of the region. I decided to take more of a
compromise between these two solutions as each have equal merit.
I kept precip chances near to or above climatology with rain
across the basin and transitioning to snow across the northern
mountain valleys; confidence this far out in the forecast period
is low at this time due to model uncertainty. /SVH


&&

.AVIATION...
18Z TAFS: Ridge of high pressure keeps VFR conditions prevailing
for most aviation sites until about 12Z. The exceptions will
continue to be near and at MWH and EAT due to fog which should
dissipate/erode through the day. A weak warm front moves through
the area spreading a wintry mix of light snow with some freezing
rain mixed in generally south of I-90 starting as early as 9Z
near KEAT and about 12Z near KGEG vicinity. Accumulations, if any,
are expected to be very light /Pelatti


&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        23  34  31  38  34  42 /  10  70  20  40  90  40
Coeur d`Alene  23  34  32  40  34  41 /  10  70  30  50  90  70
Pullman        27  39  29  42  35  42 /  30  80  20  20  90  70
Lewiston       31  40  31  44  40  47 /  30  80  10  10  80  50
Colville       22  34  26  38  36  42 /   0  30  30  70 100  40
Sandpoint      20  34  30  40  34  41 /   0  50  50  70 100  60
Kellogg        22  34  31  38  34  38 /  10  80  40  50  90  90
Moses Lake     24  35  21  37  31  48 /  40  20  10  70 100  20
Wenatchee      26  39  28  35  33  46 /  40  20  10  80 100  20
Omak           22  36  27  36  31  43 /  10  20  10  80 100  20

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Air Stagnation Advisory until Noon PST Friday for Central
     Panhandle Mountains-Coeur d`Alene Area-Idaho Palouse-
     Northern Panhandle.

     Winter Storm Watch from Friday afternoon through Saturday
     afternoon for Central Panhandle Mountains-Northern
     Panhandle.

WA...Air Stagnation Advisory until Noon PST Friday for East Slopes
     Northern Cascades-Lower Garfield and Asotin Counties-Moses
     Lake Area-Northeast Mountains-Okanogan Highlands-Spokane
     Area-Upper Columbia Basin-Washington Palouse-Waterville
     Plateau-Wenatchee Area.

     Winter Storm Watch from Friday afternoon through Saturday
     afternoon for Northeast Mountains-Okanogan Highlands.

     Winter Storm Watch from Friday morning through late Friday night
     for East Slopes Northern Cascades.

&&

$$





000
FXUS66 KOTX 192226
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
226 PM PST WED NOV 19 2014

.SYNOPSIS...
A weak weather system will arrive late tonight into Thursday with
the potential for a light wintry mix of rain...snow...and freezing
rain. A stronger, wetter and windier weather system will arrive
Friday persisting into the weekend with heavy snow amounts
possible over the mountains. The weather pattern will remain
active through the middle of next week.

&&

.DISCUSSION...

Tonight and Tomorrow....The lingering very narrow and elongated
ridging nested between longwave trofs in the vicinity of the
Aleutian Islands and Eastern North America will continue to act as
a barrier toward effective passage of weather systems through the
region. Disturbances that have tried to penetrate this ridge
continue to be weakened and sheared apart as they move through the
ridge. The expectation similar weakening and splitting will occur
with weak wrapped up warm frontal band spiraling outward from a
low pressure system working east into this ridge that is expected
to pass through Eastern Washington and Northern Idaho late tonight
and Tomorrow. With this scenario in mind cloud cover ramps up
depicting the system passage. Additionally very light QPF and snow
amounts are assigned to any locations where the pops are high,
otherwise very low pops are assigned. The warm air advection
associated with the warm front gliding over the cool air we have
in place near the surface is likely to warm to as much as +3 C or
so in spots which would allow enough melting of any falling frozen
precipitation at the upper levels to refreeze at the surface in
some locations, generally south of I-90 so a mention of light
freezing precipitation in the form of either light freezing rain
or drizzle continues to be utilized. The emphasis on this system
being weak and not doing much in terms of mixing the atmosphere
and not producing much precipitation supports the extension of the
ongoing air stagnation advisory into Friday. /Pelatti


VALLEY RAIN AND HEAVY MOUNTAIN SNOW POSSIBLE EARLY THIS WEEKEND

Tonight through Saturday...The breakdown of the current ridge will
continue through this period with a second weak wave transiting
the region Thursday night...mainly impacting the north eastern
zones with light and largely non-accumulating snow showers or
flurries. This will be another shearing wave in a developing
northern branch flow above a deep trough over the Great Basin.
Very little and weak dynamic support as well as a westerly flow in
the mid levels will probably allow this system to skip the deep
basin where the main threat of freezing rain would be with
residual arctic air slow to scrub. As it stands the main threat
will be the potential for freezing drizzle Friday morning in the
Ritzville to Moses Lake area embedded in stubborn fog in this low
laying area. Otherwise for most locations outside of the Cascades
Friday will be a seasonably cool and cloudy day. With these weak
impulses doing little to impact the boundary layer the Air
Stagnation Advisory will remain valid through noon Friday with
re-evaluation with area AQ authorities on Friday morning.

The next Pacific storm system promises to be a much wetter and
more dynamic beast. The latest NAM...GFS and ECMWF models are in
pretty good agreement regarding the timing an character of this
storm...currently visible on satellite as a large baroclinic leaf
cloud shield way out near 160W south of the Aleutians. While the
details of the frontal complex are somewhat confused...in general
a strong moist warm front through much of Friday night will be
followed by a breezy and gusty cold front during the day on
Saturday. Rich moisture will efficiently lift over the warm front
which will develop Friday afternoon over the Cascades and envelop
the entire forecast area Friday night and Saturday morning.
Precipitation will likely be almost universal...and the storm
will be strong enough to decisively scour the basin out as snow
levels rise. While mainly rain is expected in the basin and
valleys of the Idaho Panhandle and northeast mountains...the
scouring process will be retarded in the Cascade valleys
particularly north of lake Chelan...and the high terrain of the
Waterville Plateau may also hold onto snow through much of the
night. Winter Storm Watches for this storm will be issued with the
afternoon package for the Cascades in general and the mountains of
northeast Washington and north Idaho above 4000 feet.

On Saturday the cold front will move through the Cascades early in
the day promoting a downslope shutdown of steady snow except for
slop-over off the crest. The front will cross the basin and bring
gusty winds...possibly 30 to 35 mph over the exposed terrain of
the eastern basin...and promote lingering snow showers piling into
the Idaho Panhandle mountains. Temperatures on Saturday will feel
mild after the last week with a well mixed air mass promoting
adiabatic compressional warming. /Fugazzi

Saturday night and Sunday: A shortwave trough will be pushing
through the region during this period. The ECMWF has sped up
to become more in line with the GFS on the timing of this
trough. The precip associated with this system will be mainly rain
for the Columbia Basin with a few flurries and snow for the
mountains. The mountain passes can expect to receive around 3
inches from this system. The northern mountains are expected to
receive at most an inch. Daytime temperatures will range from the
upper 30s to low 40s. The nighttime temperatures will range from
the upper 20s to low 30s. This could produce icy patches along the
roads during the night and early morning hours throughout the
Inland Northwest. /JDC

Monday through Wednesday: Model discrepancy is high out this far
in the forecast period. The ECMWF and GFS model runs show a more
active weather regime; whereas, the Canadian model shows a strong
ridge building in over the region with a return of drier and
stable conditions. The Canadian solution is the outlier and was
ignored. The difference between the GFS and ECMWF solutions is
that the GFS shows more of a zonal flow pattern setting up over
the region with stronger connections to a sub-tropical moisture
fetch. The ECMWF model continues with a more northwest oriented
flow pattern and takes the bulk of the moisture off of the Pacific
into Oregon, which then only clips the southern portion of the
forecast area. The GFS solution would result in a wetter and
milder scenario and a better chance for snow levels to rise above
valley floors. The ECMWF is colder and keeps a chance for valley
snow across much of the region. I decided to take more of a
compromise between these two solutions as each have equal merit.
I kept precip chances near to or above climatology with rain
across the basin and transitioning to snow across the northern
mountain valleys; confidence this far out in the forecast period
is low at this time due to model uncertainty. /SVH


&&

.AVIATION...
18Z TAFS: Ridge of high pressure keeps VFR conditions prevailing
for most aviation sites until about 12Z. The exceptions will
continue to be near and at MWH and EAT due to fog which should
dissipate/erode through the day. A weak warm front moves through
the area spreading a wintry mix of light snow with some freezing
rain mixed in generally south of I-90 starting as early as 9Z
near KEAT and about 12Z near KGEG vicinity. Accumulations, if any,
are expected to be very light /Pelatti


&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        23  34  31  38  34  42 /  10  70  20  40  90  40
Coeur d`Alene  23  34  32  40  34  41 /  10  70  30  50  90  70
Pullman        27  39  29  42  35  42 /  30  80  20  20  90  70
Lewiston       31  40  31  44  40  47 /  30  80  10  10  80  50
Colville       22  34  26  38  36  42 /   0  30  30  70 100  40
Sandpoint      20  34  30  40  34  41 /   0  50  50  70 100  60
Kellogg        22  34  31  38  34  38 /  10  80  40  50  90  90
Moses Lake     24  35  21  37  31  48 /  40  20  10  70 100  20
Wenatchee      26  39  28  35  33  46 /  40  20  10  80 100  20
Omak           22  36  27  36  31  43 /  10  20  10  80 100  20

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Air Stagnation Advisory until Noon PST Friday for Central
     Panhandle Mountains-Coeur d`Alene Area-Idaho Palouse-
     Northern Panhandle.

     Winter Storm Watch from Friday afternoon through Saturday
     afternoon for Central Panhandle Mountains-Northern
     Panhandle.

WA...Air Stagnation Advisory until Noon PST Friday for East Slopes
     Northern Cascades-Lower Garfield and Asotin Counties-Moses
     Lake Area-Northeast Mountains-Okanogan Highlands-Spokane
     Area-Upper Columbia Basin-Washington Palouse-Waterville
     Plateau-Wenatchee Area.

     Winter Storm Watch from Friday afternoon through Saturday
     afternoon for Northeast Mountains-Okanogan Highlands.

     Winter Storm Watch from Friday morning through late Friday night
     for East Slopes Northern Cascades.

&&

$$




000
FXUS66 KPQR 191811
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
1010 AM PST WED NOV 19 2014

.SYNOPSIS...THE COOL DRY WEATHER PATTERN OF THE PAST WEEK WILL BE ON
THE WAY OUT TODAY AS A SERIES OF STORMS COMES IN OFF THE PACIFIC
OVER THE COMING DAYS. A WINTRY MIX OF PRECIPITATION WILL LIKELY FALL
IN THE COLUMBIA RIVER GORGE TONIGHT AND EARLY THURSDAY. EXPECT
TEMPERATURES TO MODERATE TO NEAR NORMAL ELSEWHERE DURING THIS
PERIOD. A WET...WINDY AND STRONGER STORM SYSTEM LOOKS TO ARRIVE
FRIDAY. ADDITIONAL ROUNDS OF RAIN WILL FALL OVER THE WEEKEND. LOWER
SNOW LEVELS MAY BRING SIGNIFICANT SNOW ACCUMULATIONS TO THE CASCADES
PASSES OVER THE WEEKEND.

&&

.UPDATE...MAIN ISSUE FOR THE MORNING PACKAGE WAS TO ISSUE A FREEZING
RAIN ADVISORY FOR THE GORGE AND UPPER HOOD RIVER VALLEY. COLD POOL
EAST OF THE CASCADES REMAINS WELL ENTRENCHED. EASTERLY PRESSURE
GRADIENT BETWEEN THE DALLES AND TROUTDALE PEAKED AGAIN THIS MORNING
THIS TIME AT 11.6 MB. WILL CONTINUE TO SEE THE GUSTY EAST WINDS DRAW
THAT COLD AIR THROUGH THE GORGE UNTIL GRADIENTS EASE OVERNIGHT. THEY
WILL STAY LIGHT EASTERLY HOWEVER SO HAVE SIGNIFICANT DOUBTS THE
GORGE...AND ESPECIALLY THE CENTRAL GORGE...WILL GET MUCH WARMER OVER
THE NEXT COUPLE DAYS. THE SYSTEM COMING IN TONIGHT STILL LOOKS LIKE
IT WILL HOLD TOGETHER ENOUGH TO BRING A NOTABLE THREAT OF FREEZING
RAIN AND/OR SLEET TO THE GORGE AREAS PRIMARILY EAST OF SKAMANIA BUT
EXPECT THE COLDER AIR WILL CONTINUE TO SEEP FURTHER WEST AS WELL AND
HAVE SOME IMPACTS CLOSER TO CORBETT.

AS MENTIONED PREVIOUSLY...DONT YET HAVE MUCH FAITH IN MODELED GORGE
TEMPERATURES RISING ABOVE FREEZING UNTIL PERHAPS LATER THURSDAY
NIGHT OR FRIDAY MORNING WHEN THE SURFACE PRESSURE GRADIENT TRULY
BECOMES WESTERLY. EXPERIENCE SHOWS MODELS ATTEMPT TO WARM UP THE
GORGE BY MIXING FROM ABOVE BUT THE COLDER DENSER AIR FROM EAST OF
THE CASCADES COMMONLY UNDERCUTS THAT MIXED LAYER UNTIL A SOLID
WESTERLY WIND PUSHES THROUGH THE LOWEST TERRAIN. AS SUCH WILL BE
KEEPING A CLOSE EYE ON WHAT ACTUALLY OCCURS TONIGHT AND EARLY
TOMORROW. IF THE HUNCH IS CORRECT...THE INCOMING SYSTEM FRIDAY COULD
PRESENT A SIGNIFICANT THREAT FOR AN ICE STORM COVERING AT LEAST THE
CENTRAL GORGE AND HOOD RIVER VALLEY...IF NOT THE WESTERN GORGE AS
WELL. THE ONE FACTOR IN FAVOR OF THE WARMING IS WE ARE STILL ON THE
DOWNWARD GLIDE SLOPE HEADING INTO CALENDAR WINTER. AM PRELIMINARY
PLANNING ON ISSUING A SPECIAL WEATHER STATEMENT AS A FIRST HEADS UP
AS PART OF THE AFTERNOON PACKAGE WITH THE BATTLE BETWEEN EXPERIENCE
AND THE UNCERTAINTY LEADING THE DISCUSSION. /JBONK


&&

.PREV DISC... /ISSUED 409 AM PST WED NOV 19 2014/

SHORT TERM...LOW LEVEL FLOW REMAINS OFFSHORE EARLY THIS MORNING...
WITH GRADIENTS THROUGH THE GORGE BETWEEN KDLS AND KPDX STILL ON THE
ORDER OF 9 TO 10 MB. TEMPS HOWEVER NOT QUITE AS COOL AS PAST FEW
NIGHTS THANKS TO A FAIRLY SOLID MID TO HIGH LEVEL CLOUD COVER. STILL
COLD THOUGH IN THE CENTRAL GORGE AND HOOD RIVER VALLEY WITH TEMPS
DOWN NEAR 20. OFFSHORE FLOW WILL CONTINUE THROUGH THE GORGE THROUGH
TONIGHT AND PERHAPS AS LONG AS INTO FRI...MEANING THE COLD AIR MASS
IN PLACE ON THE E SIDE WILL BE DIFFICULT TO MODIFY OR DISLODGE UNTIL
THEN. MODEL CONTINUE TO INDICATE THE RIDGE ALOFT OVER THE REGION
THIS MORNING WILL PUSH OFF TO THE E TODAY ALLOWING A SERIES OF
SHORTWAVES TO COME IN OFF THE PACIFIC. INITIALLY THOUGH THE SHORT
WAVES WILL TEND TO THE WEAK SIDE AND BE PRONE TO SPLITTING AS THEY
MOVE INTO THE RIDGE POSITION. THE FIRST SHORTWAVE APPROACHING THE
COAST THIS MORNING IS EXPECTED TO LIFT THROUGH THE REGION LATE TODAY
AND TONIGHT...WITH THE MAIN ENERGY SPLITTING OFF TO THE S AND TO A
LESSER DEGREE TO THE NW. MOISTURE FIELDS ALSO NOT PARTICULARLY
IMPRESSIVE...WITH LOW LEVEL MOISTURE GENERALLY SHOWN BELOW 7 TO 8
THOUSAND FEET IN MODEL CROSS SECTIONS. PROBABLY ADEQUATE LIFT AND
MOISTURE TO CONTINUE WITH LIKELY TO CATEGORICAL POPS LATE TODAY INTO
TONIGHT. TEMPS IN THE GORGE AND HOOD RIVER VALLEY LIKELY TO REMAIN
BELOW FREEZING FOR THIS EVENT SUGGESTING FREEZING RAIN OR SLEET THE
MOST LIKELY PRECIPITATION TYPE THERE...BUT STILL HARBOR SOME
CONCERNS OVER PRECIPITATION POTENTIAL GIVEN THE SPLITTING SYSTEM AD
DRY LOW LEVEL AIR MASS CURRENTLY IN PLACE...SO PREFER TO HOLD OFF
WITH ANY ADVISORY TYPE HEADLINES THERE FOR THE TIME BEING.

ONCE THE FIRST SHORT WAVE MOVES THROUGH OVERNIGHT...NEXT SHORTWAVE
APPEARS TO BE DIRECTED PRIMARILY TO THE S OF THE FORECAST AREA THU
MORNING. WILL CARRY HIGHEST POPS ACROSS THE S OF THE FORECAST
AREA...WITH MAINLY CHANCE POPS ACROSS THE N. PRECIPITATION TYPE IN
THE GORGE AND HOOD RIVER VALLEY REMAINS PROBLEMATIC AS IT IS NOT
CLEAR THAT THE COLD AIR MASS IS DISLODGED BY THE PREVIOUS SYSTEM THU
NIGHT. W OF THE CASCADES THOUGH THE FIRST TROUGH APPEARS TO GENERATE
ENOUGH OF A SOUTHERLY FLOW BEHIND IT TONIGHT AND EARLY THU TO MODIFY
THE AIR MASS BACK TO A MORE MARITIME TYPE...MEANING TEMPS SHOULD
RETURN BACK TO MORE SEASONABLE NORMALS.

NEXT SYSTEM SHOWN IN MODELS ARRIVES FRI AS THE UPPER FLOW
STRENGTHENS AND TURNS WESTERLY...PUSHING AN OCCLUDED FRONT TO NEAR
THE COAST BY THE END OF THE DAY. DEEPER MOISTURE AND STRONGER FLOW
GENERATE BETTER MOISTURE TRANSPORT...WHICH WITH ISENTROPIC LIFTING
APPEARS ON TRACK TO PRODUCE A WET DAY. WITH GOOD AGREEMENT IN
MODELS...WILL RAISE POPS TO CATEGORICAL THROUGHOUT THE FORECAST
AREA.

LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS. FRIDAY NIGHT
THROUGH TUESDAY. THE STRONGER FRONTAL SYSTEM AND UPPER LEVEL
SHORTWAVE TROUGH PUSH INTO SW WASHINGTON AND NW OREGON ON LATER
FRIDAY OR FRIDAY NIGHT...AND MODELS SUGGEST A GOOD DOSE OF RAIN
LIKELY MUCH ACROSS THE REGION. SNOW LEVELS FALL TO AROUND 4000 FT SO
MAY SEE SOME SNOW DOWN TO NEAR THE CASCADE PASSES SATURDAY INTO
EARLY SUNDAY. MOISTURE TAPERS OFF BUT SOME SHOWERS MAY CONTINUE
THROUGH SUNDAY. SOME BROAD UPPER LEVEL RIDGING LOOKS TO DEVELOP
EARLY NEXT WEEK...ALLOWING A SERIES OF SHORTWAVES TO TRAVERSE THE
AREA BRINGING WAVES OF RAIN UNDER WESTERLY FLOW. THIS MORE ACTIVE
WEATHER PATTERN WILL BRING A MORE MARINE INFLUENCE TO OUR AIR
MASS...KEEPING TEMPERATURES NEAR SEASONAL NORMS THROUGH THE LONG
TERM PERIOD. CULLEN


&&

.AVIATION...PSEUDO-WARM FRONT MOVES ACROSS OUR AREA THIS
AFTERNOON. SYSTEM HAS SLOWED SOME...SO ONSET OF RAIN CHANCE AND
MID AND HIGH LEVEL CLOUDS WILL BE DELAYED. OVERALL...VFR CIGS AND
VISIBILITY THROUGH TODAY. A SLIGHTLY WARMER AIR MASS BEHIND THIS
FRONT BRINGS CHANCE FOR MVFR TO IFR CONDITIONS THIS EVENING
THROUGH THE NIGHT TONIGHT. HISTORICALLY...SOUTHERLY WINDS INCREASE
OCCURRENCE OF MVFR CONDITIONS...SO COASTAL LOCATIONS...KSLE...AND
KEUG HAVE A GOOD CHANCE FOR MVFR TONIGHT. AT NORTH WILLAMETTE
VALLEY SITES...DRY EASTERLY WIND WILL INHIBIT THE ONSET OF LOWER
CIGS UNTIL LATER...IF AT ALL.

KTTD IS STILL WINDY...WITH EASTERLY WINDS AROUND 25 KTS GUSTING TO
35 KTS. PRESSURE GRADIENT WILL CONTINUE TO RELAX THROUGH THE
DAY ACROSS THE GORGE...BUT SIMILAR TO LAST TWO DAYS WINDS SHOULD
STAY AROUND 2O TO 25 KTS GUSTING TO 35 KTS UNTIL AFTER THE FRONT
MOVES THROUGH...AROUND 03Z THURSDAY...WHEN WIND SPEED BEGINS TO
DECREASE.

KPDX AND APPROACHES...VFR PREVAILING THROUGH EARLY THIS EVENING AS
DRY EASTERLY FLOW CONTINUES. AFTER ABOUT 06Z THU INCREASING RAIN MAY
BRING MVFR TO IFR CONDITIONS. STRONG EAST WINDS ARE EXPECTED TO
CONTINUE NEAR KTTD WITH GUSTS TO 35 KTS THROUGH AROUND 03Z THU.

-MCCOY

&&

.MARINE...WIND THIS MORNING GENERALLY BELOW 20 KTS...BUT GUSTS
FREQUENTLY REACHING ABOVE 21 KTS NEAR GAPS IN COASTAL TERRAIN.
WINDS WILL INCREASE TO MORE WIDESPREAD WINDS FREQUENTLY GUSTING
NEAR 25 TO 30 KTS...ESPECIALLY IN OUTER WATERS. THESE WINDS WILL
PEAK THIS EVENING...RAMPING DOWN OVERNIGHT TONIGHT INTO THURSDAY.
SEAS 7 TO 9 FT CURRENTLY AND WILL CONTINUE TO BUILD TODAY. SEAS
WILL PEAK AROUND 13 FT LATE TONIGHT AND BEGIN TO GRADUALLY SUBSIDE
THURSDAY MORNING.

STRONGER WEATHER SYSTEM WILL MOVE THROUGH ON FRIDAY. GALES ARE
VERY POSSIBLE ON FRIDAY AHEAD OF FRONTAL PASSAGE ACROSS OUR
WATERS. THERE MIGHT BE A BRIEF PERIOD OF SEAS BELOW 10 FT
THURSDAY...BUT STARTING TO LOOK LESS LIKELY. SEAS START TO BUILD
AGAIN LATE THURSDAY OR EARLY FRIDAY...REACHING THE MIDDLE TEENS BY
MID-DAY FRIDAY. SEAS LOOK TO REMAIN ABOVE 10 FT OVER THE WEEKEND...
WITH AN ACTIVE WEATHER PATTERN LOOKING LIKELY TO KEEP SEAS UP THROUGH
EARLY NEXT WEEK.

-MCCOY

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING RAIN ADVISORY FROM 6 PM THIS EVENING TO 4 AM PST
     THURSDAY FOR CENTRAL COLUMBIA RIVER GORGE-UPPER HOOD RIVER
     VALLEY-WESTERN COLUMBIA RIVER GORGE.

WA...FREEZING RAIN ADVISORY FROM 6 PM THIS EVENING TO 4 AM PST
     THURSDAY FOR CENTRAL COLUMBIA RIVER GORGE-WESTERN COLUMBIA
     RIVER GORGE.

PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 AM PST THURSDAY FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 AM PST THURSDAY
     FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60
     NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 1 PM THIS
     AFTERNOON TO 6 AM PST THURSDAY.

&&


$$

INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND

THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.




000
FXUS66 KPQR 191811
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
1010 AM PST WED NOV 19 2014

.SYNOPSIS...THE COOL DRY WEATHER PATTERN OF THE PAST WEEK WILL BE ON
THE WAY OUT TODAY AS A SERIES OF STORMS COMES IN OFF THE PACIFIC
OVER THE COMING DAYS. A WINTRY MIX OF PRECIPITATION WILL LIKELY FALL
IN THE COLUMBIA RIVER GORGE TONIGHT AND EARLY THURSDAY. EXPECT
TEMPERATURES TO MODERATE TO NEAR NORMAL ELSEWHERE DURING THIS
PERIOD. A WET...WINDY AND STRONGER STORM SYSTEM LOOKS TO ARRIVE
FRIDAY. ADDITIONAL ROUNDS OF RAIN WILL FALL OVER THE WEEKEND. LOWER
SNOW LEVELS MAY BRING SIGNIFICANT SNOW ACCUMULATIONS TO THE CASCADES
PASSES OVER THE WEEKEND.

&&

.UPDATE...MAIN ISSUE FOR THE MORNING PACKAGE WAS TO ISSUE A FREEZING
RAIN ADVISORY FOR THE GORGE AND UPPER HOOD RIVER VALLEY. COLD POOL
EAST OF THE CASCADES REMAINS WELL ENTRENCHED. EASTERLY PRESSURE
GRADIENT BETWEEN THE DALLES AND TROUTDALE PEAKED AGAIN THIS MORNING
THIS TIME AT 11.6 MB. WILL CONTINUE TO SEE THE GUSTY EAST WINDS DRAW
THAT COLD AIR THROUGH THE GORGE UNTIL GRADIENTS EASE OVERNIGHT. THEY
WILL STAY LIGHT EASTERLY HOWEVER SO HAVE SIGNIFICANT DOUBTS THE
GORGE...AND ESPECIALLY THE CENTRAL GORGE...WILL GET MUCH WARMER OVER
THE NEXT COUPLE DAYS. THE SYSTEM COMING IN TONIGHT STILL LOOKS LIKE
IT WILL HOLD TOGETHER ENOUGH TO BRING A NOTABLE THREAT OF FREEZING
RAIN AND/OR SLEET TO THE GORGE AREAS PRIMARILY EAST OF SKAMANIA BUT
EXPECT THE COLDER AIR WILL CONTINUE TO SEEP FURTHER WEST AS WELL AND
HAVE SOME IMPACTS CLOSER TO CORBETT.

AS MENTIONED PREVIOUSLY...DONT YET HAVE MUCH FAITH IN MODELED GORGE
TEMPERATURES RISING ABOVE FREEZING UNTIL PERHAPS LATER THURSDAY
NIGHT OR FRIDAY MORNING WHEN THE SURFACE PRESSURE GRADIENT TRULY
BECOMES WESTERLY. EXPERIENCE SHOWS MODELS ATTEMPT TO WARM UP THE
GORGE BY MIXING FROM ABOVE BUT THE COLDER DENSER AIR FROM EAST OF
THE CASCADES COMMONLY UNDERCUTS THAT MIXED LAYER UNTIL A SOLID
WESTERLY WIND PUSHES THROUGH THE LOWEST TERRAIN. AS SUCH WILL BE
KEEPING A CLOSE EYE ON WHAT ACTUALLY OCCURS TONIGHT AND EARLY
TOMORROW. IF THE HUNCH IS CORRECT...THE INCOMING SYSTEM FRIDAY COULD
PRESENT A SIGNIFICANT THREAT FOR AN ICE STORM COVERING AT LEAST THE
CENTRAL GORGE AND HOOD RIVER VALLEY...IF NOT THE WESTERN GORGE AS
WELL. THE ONE FACTOR IN FAVOR OF THE WARMING IS WE ARE STILL ON THE
DOWNWARD GLIDE SLOPE HEADING INTO CALENDAR WINTER. AM PRELIMINARY
PLANNING ON ISSUING A SPECIAL WEATHER STATEMENT AS A FIRST HEADS UP
AS PART OF THE AFTERNOON PACKAGE WITH THE BATTLE BETWEEN EXPERIENCE
AND THE UNCERTAINTY LEADING THE DISCUSSION. /JBONK


&&

.PREV DISC... /ISSUED 409 AM PST WED NOV 19 2014/

SHORT TERM...LOW LEVEL FLOW REMAINS OFFSHORE EARLY THIS MORNING...
WITH GRADIENTS THROUGH THE GORGE BETWEEN KDLS AND KPDX STILL ON THE
ORDER OF 9 TO 10 MB. TEMPS HOWEVER NOT QUITE AS COOL AS PAST FEW
NIGHTS THANKS TO A FAIRLY SOLID MID TO HIGH LEVEL CLOUD COVER. STILL
COLD THOUGH IN THE CENTRAL GORGE AND HOOD RIVER VALLEY WITH TEMPS
DOWN NEAR 20. OFFSHORE FLOW WILL CONTINUE THROUGH THE GORGE THROUGH
TONIGHT AND PERHAPS AS LONG AS INTO FRI...MEANING THE COLD AIR MASS
IN PLACE ON THE E SIDE WILL BE DIFFICULT TO MODIFY OR DISLODGE UNTIL
THEN. MODEL CONTINUE TO INDICATE THE RIDGE ALOFT OVER THE REGION
THIS MORNING WILL PUSH OFF TO THE E TODAY ALLOWING A SERIES OF
SHORTWAVES TO COME IN OFF THE PACIFIC. INITIALLY THOUGH THE SHORT
WAVES WILL TEND TO THE WEAK SIDE AND BE PRONE TO SPLITTING AS THEY
MOVE INTO THE RIDGE POSITION. THE FIRST SHORTWAVE APPROACHING THE
COAST THIS MORNING IS EXPECTED TO LIFT THROUGH THE REGION LATE TODAY
AND TONIGHT...WITH THE MAIN ENERGY SPLITTING OFF TO THE S AND TO A
LESSER DEGREE TO THE NW. MOISTURE FIELDS ALSO NOT PARTICULARLY
IMPRESSIVE...WITH LOW LEVEL MOISTURE GENERALLY SHOWN BELOW 7 TO 8
THOUSAND FEET IN MODEL CROSS SECTIONS. PROBABLY ADEQUATE LIFT AND
MOISTURE TO CONTINUE WITH LIKELY TO CATEGORICAL POPS LATE TODAY INTO
TONIGHT. TEMPS IN THE GORGE AND HOOD RIVER VALLEY LIKELY TO REMAIN
BELOW FREEZING FOR THIS EVENT SUGGESTING FREEZING RAIN OR SLEET THE
MOST LIKELY PRECIPITATION TYPE THERE...BUT STILL HARBOR SOME
CONCERNS OVER PRECIPITATION POTENTIAL GIVEN THE SPLITTING SYSTEM AD
DRY LOW LEVEL AIR MASS CURRENTLY IN PLACE...SO PREFER TO HOLD OFF
WITH ANY ADVISORY TYPE HEADLINES THERE FOR THE TIME BEING.

ONCE THE FIRST SHORT WAVE MOVES THROUGH OVERNIGHT...NEXT SHORTWAVE
APPEARS TO BE DIRECTED PRIMARILY TO THE S OF THE FORECAST AREA THU
MORNING. WILL CARRY HIGHEST POPS ACROSS THE S OF THE FORECAST
AREA...WITH MAINLY CHANCE POPS ACROSS THE N. PRECIPITATION TYPE IN
THE GORGE AND HOOD RIVER VALLEY REMAINS PROBLEMATIC AS IT IS NOT
CLEAR THAT THE COLD AIR MASS IS DISLODGED BY THE PREVIOUS SYSTEM THU
NIGHT. W OF THE CASCADES THOUGH THE FIRST TROUGH APPEARS TO GENERATE
ENOUGH OF A SOUTHERLY FLOW BEHIND IT TONIGHT AND EARLY THU TO MODIFY
THE AIR MASS BACK TO A MORE MARITIME TYPE...MEANING TEMPS SHOULD
RETURN BACK TO MORE SEASONABLE NORMALS.

NEXT SYSTEM SHOWN IN MODELS ARRIVES FRI AS THE UPPER FLOW
STRENGTHENS AND TURNS WESTERLY...PUSHING AN OCCLUDED FRONT TO NEAR
THE COAST BY THE END OF THE DAY. DEEPER MOISTURE AND STRONGER FLOW
GENERATE BETTER MOISTURE TRANSPORT...WHICH WITH ISENTROPIC LIFTING
APPEARS ON TRACK TO PRODUCE A WET DAY. WITH GOOD AGREEMENT IN
MODELS...WILL RAISE POPS TO CATEGORICAL THROUGHOUT THE FORECAST
AREA.

LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS. FRIDAY NIGHT
THROUGH TUESDAY. THE STRONGER FRONTAL SYSTEM AND UPPER LEVEL
SHORTWAVE TROUGH PUSH INTO SW WASHINGTON AND NW OREGON ON LATER
FRIDAY OR FRIDAY NIGHT...AND MODELS SUGGEST A GOOD DOSE OF RAIN
LIKELY MUCH ACROSS THE REGION. SNOW LEVELS FALL TO AROUND 4000 FT SO
MAY SEE SOME SNOW DOWN TO NEAR THE CASCADE PASSES SATURDAY INTO
EARLY SUNDAY. MOISTURE TAPERS OFF BUT SOME SHOWERS MAY CONTINUE
THROUGH SUNDAY. SOME BROAD UPPER LEVEL RIDGING LOOKS TO DEVELOP
EARLY NEXT WEEK...ALLOWING A SERIES OF SHORTWAVES TO TRAVERSE THE
AREA BRINGING WAVES OF RAIN UNDER WESTERLY FLOW. THIS MORE ACTIVE
WEATHER PATTERN WILL BRING A MORE MARINE INFLUENCE TO OUR AIR
MASS...KEEPING TEMPERATURES NEAR SEASONAL NORMS THROUGH THE LONG
TERM PERIOD. CULLEN


&&

.AVIATION...PSEUDO-WARM FRONT MOVES ACROSS OUR AREA THIS
AFTERNOON. SYSTEM HAS SLOWED SOME...SO ONSET OF RAIN CHANCE AND
MID AND HIGH LEVEL CLOUDS WILL BE DELAYED. OVERALL...VFR CIGS AND
VISIBILITY THROUGH TODAY. A SLIGHTLY WARMER AIR MASS BEHIND THIS
FRONT BRINGS CHANCE FOR MVFR TO IFR CONDITIONS THIS EVENING
THROUGH THE NIGHT TONIGHT. HISTORICALLY...SOUTHERLY WINDS INCREASE
OCCURRENCE OF MVFR CONDITIONS...SO COASTAL LOCATIONS...KSLE...AND
KEUG HAVE A GOOD CHANCE FOR MVFR TONIGHT. AT NORTH WILLAMETTE
VALLEY SITES...DRY EASTERLY WIND WILL INHIBIT THE ONSET OF LOWER
CIGS UNTIL LATER...IF AT ALL.

KTTD IS STILL WINDY...WITH EASTERLY WINDS AROUND 25 KTS GUSTING TO
35 KTS. PRESSURE GRADIENT WILL CONTINUE TO RELAX THROUGH THE
DAY ACROSS THE GORGE...BUT SIMILAR TO LAST TWO DAYS WINDS SHOULD
STAY AROUND 2O TO 25 KTS GUSTING TO 35 KTS UNTIL AFTER THE FRONT
MOVES THROUGH...AROUND 03Z THURSDAY...WHEN WIND SPEED BEGINS TO
DECREASE.

KPDX AND APPROACHES...VFR PREVAILING THROUGH EARLY THIS EVENING AS
DRY EASTERLY FLOW CONTINUES. AFTER ABOUT 06Z THU INCREASING RAIN MAY
BRING MVFR TO IFR CONDITIONS. STRONG EAST WINDS ARE EXPECTED TO
CONTINUE NEAR KTTD WITH GUSTS TO 35 KTS THROUGH AROUND 03Z THU.

-MCCOY

&&

.MARINE...WIND THIS MORNING GENERALLY BELOW 20 KTS...BUT GUSTS
FREQUENTLY REACHING ABOVE 21 KTS NEAR GAPS IN COASTAL TERRAIN.
WINDS WILL INCREASE TO MORE WIDESPREAD WINDS FREQUENTLY GUSTING
NEAR 25 TO 30 KTS...ESPECIALLY IN OUTER WATERS. THESE WINDS WILL
PEAK THIS EVENING...RAMPING DOWN OVERNIGHT TONIGHT INTO THURSDAY.
SEAS 7 TO 9 FT CURRENTLY AND WILL CONTINUE TO BUILD TODAY. SEAS
WILL PEAK AROUND 13 FT LATE TONIGHT AND BEGIN TO GRADUALLY SUBSIDE
THURSDAY MORNING.

STRONGER WEATHER SYSTEM WILL MOVE THROUGH ON FRIDAY. GALES ARE
VERY POSSIBLE ON FRIDAY AHEAD OF FRONTAL PASSAGE ACROSS OUR
WATERS. THERE MIGHT BE A BRIEF PERIOD OF SEAS BELOW 10 FT
THURSDAY...BUT STARTING TO LOOK LESS LIKELY. SEAS START TO BUILD
AGAIN LATE THURSDAY OR EARLY FRIDAY...REACHING THE MIDDLE TEENS BY
MID-DAY FRIDAY. SEAS LOOK TO REMAIN ABOVE 10 FT OVER THE WEEKEND...
WITH AN ACTIVE WEATHER PATTERN LOOKING LIKELY TO KEEP SEAS UP THROUGH
EARLY NEXT WEEK.

-MCCOY

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING RAIN ADVISORY FROM 6 PM THIS EVENING TO 4 AM PST
     THURSDAY FOR CENTRAL COLUMBIA RIVER GORGE-UPPER HOOD RIVER
     VALLEY-WESTERN COLUMBIA RIVER GORGE.

WA...FREEZING RAIN ADVISORY FROM 6 PM THIS EVENING TO 4 AM PST
     THURSDAY FOR CENTRAL COLUMBIA RIVER GORGE-WESTERN COLUMBIA
     RIVER GORGE.

PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 AM PST THURSDAY FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 AM PST THURSDAY
     FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60
     NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 1 PM THIS
     AFTERNOON TO 6 AM PST THURSDAY.

&&


$$

INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND

THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.



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