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000
FXUS66 KSEW 280514
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
910 PM PST THU NOV 27 2014

.SYNOPSIS...A COLD FRONT WILL MOVE SOUTH ACROSS WESTERN WA LATE
TONIGHT AND FRIDAY MORNING PRODUCING HEAVY RAIN OVER THE MOUNTAINS
AND OVER PARTS OF THE PUGET SOUND REGION. A CONVERGENCE ZONE WILL
CONTINUE OVER PUGET SOUND FRIDAY NIGHT...THEN ANOTHER COLD FRONT
WITH MODIFIED ARCTIC AIR WILL MOVE SOUTH THROUGH THE AREA LATE
FRIDAY NIGHT INTO SATURDAY MORNING. SOME SNOW OR RAIN AND SNOW MIXED
IS LIKELY TO OCCUR WITH THE CONVERGENCE ZONE AND ALONG THIS SECOND
FRONT. COOL NORTHWEST FLOW ALOFT WILL BRING MAINLY COOL AND DRY
WEATHER SUNDAY THROUGH EARLY NEXT WEEK.

&&

.SHORT TERM...VARIABILITY APPEARS TO BE THE BEST WORD TO DESCRIBE
THE SHORT TERM FORECAST. CURRENT RADAR SHOWS RAIN NOT QUITE AS
WIDESPREAD AS INITIALLY THOUGHT OR FORECAST...WITH PRECIP EAST OF
THE SOUND CONFINED PRIMARILY TO THE CASCADES. AS UPCOMING FRONT
STARTS TO MAKE ITS WAY INTO THE AREA OVERNIGHT TONIGHT AND INTO
TOMORROW...SHOULD SEE THAT HOLE START TO FILL IN. CURRENT IR
SATELLITE IMAGERY GIVES PAUSE TO THAT THOUGHT HOWEVER. IF FRONTAL
MOVEMENT ADHERES TO SOUTHEAST MOTION AS FORECAST...CLOUD LAYERS WILL
LOOK TO BE FAIRLY SHALLOW AND THUS WHILE RAIN REMAINS A FAIR
POSSIBILITY...MIGHT BE LESS THAN ADVERTISED. THROWING ANOTHER
HOWEVER IN THE MIX THOUGH IS THE CURRENT TREND IN SAID IR IMAGERY TO
SHOW SOME BUILDING IN CLOUDS. THUS...AT THIS TIME AM INCLINED TO
SIDE WITH THOUGHT THAT THINGS JUST GOT STARTED A BIT LATER THAN
PROGGED AND LEAVE INHERITED FORECAST INTACT.

MODELS REMAIN CONSISTENT WITH THE FORECAST FOR FRIDAY AND INTO
SATURDAY AS THE FRONT SLOWLY MAKES ITS WAY THROUGH WESTERN
WASHINGTON BY LATE FRIDAY MORNING AND PRODUCING RAIN FOR MOST
LOCATIONS FOR MUCH OF THE DAY. TEMPERATURES WILL FALL STEADILY
THROUGH THE DAY FRIDAY AFTER FROPA AS COLDER AIR STARTS TO MAKE ITS
WAY IN. SUFFICIENT MOISTURE IS EXPECTED TO LINGER AND COUPLED WITH A
CONVERGENCE ZONE STILL PRESENT IN CURRENT MODEL OUTPUT...CONDITIONS
STILL LOOK FAVORABLE FOR RAIN TO TRANSITION INTO MIXED PRECIPITATION
FRIDAY NIGHT AND LOWLAND SNOW FOR OVERNIGHT FRIDAY AND INTO SATURDAY
MORNING. A LOT OF THIS STILL DEPENDS ON TIMING OF FACTORS...AND AS
THE PREVIOUS PARAGRAPH OPENED...VARIABILITY HAS BEEN THE WATCH WORD
FOR THE FORECAST TONIGHT. THAT SAID...STILL OPTING TO PLAY SNOW
EVENT ON LOW END OF THINGS FOR NOW...WITH MOST LOWLAND LOCATIONS
THAT DO SEE FLAKES SEEING LESS THAN AN INCH. PASSING UPPER LEVEL
TROUGH SCOURS MOISTURE OUT QUICKLY BY LATE SATURDAY MORNING. THAT
AND SURFACE HIGH PRESSURE MOVING INTO SOUTHERN BRITISH COLUMBIA WILL
SET THE STAGE FOR COLDER TEMPERATURES THIS WEEKEND. ALSO OF NOTE
WITH THAT SURFACE HIGH WILL BE THE DEVELOPMENT OF FRASER OUTFLOW
WINDS. AT THIS TIME...HIGH WIND WATCH IS IN PLACE TO COVER TIME
FRAME FROM FRIDAY NIGHT INTO SATURDAY...MAINLY FOCUSING ON WESTERN
WHATCOM...COASTAL SKAGIT AND SAN JUANS...EVEN THOUGH WIND SPEEDS MAY
ONLY MAKE ADVISORY CRITERIA. ANOTHER MODEL RUN SHOULD BE ENOUGH TO
DECIDE WHETHER OR NOT TO UPGRADE.

STILL LOOKING CLEAR AND COLD FOR SUNDAY WITH TEMPERATURES SLOWLY
REBOUNDING MONDAY. SMR

.LONG TERM...FROM 408 PM DISCUSSION...ONLY MINOR CHANGES WERE MADE
TO THE LONG TERM FORECAST...MONDAY THROUGH THURSDAY. THE SET-UP HAS
A NORTHERN STREAM RIDGE OFFSHORE OVER THE NE PACIFIC...WITH COOL NW
FLOW ALOFT OVER W WA. ALSO IN THE PICTURE IS A SOUTHERN STREAM
CLOSED LOW W OF THE CA COAST. WASHINGTON APPEARS TO BE CONTESTED
TERRITORY BETWEEN THE NORTHERN AND SOUTHERN STREAMS WHICH MEANS
MODEL BATTLES TO DETERMINE WHICH STREAM WILL WIN OUT. THE ECMWF HAS
BEEN MORE OR LESS CONSISTENTLY KEEPING THE AREA UNDER THE COOLER
DRIER AND SUNNIER N STREAM THROUGH MID NEXT WEEK. THE GFS HAS BEEN
WOBBLING BETWEEN THE ECMWF SOLUTION AND A WETTER SOUTHERN STREAM
SOLUTION. FORECASTS CONTINUE TO FOLLOW THE ECMWF...BUT CONFIDENCE IS
ONLY MODERATE GIVEN THE MODEL CONFLICTS AND THE OVERALL DIFFICULTY
IN RESOLVING A PATTERN LIKE THIS. MODELS DO AGREE THAT A SHORTWAVE
TROUGH WILL MOVE SE ACROSS THE AREA ON MONDAY. THIS LOOKS DRY AT
THIS POINT BUT MORE CLOUDS AND POSSIBLY SOME LIGHT PRECIP MAY NEED
TO BE ADDED TO THE FORECAST IF MODEL SOLUTIONS CHANGE. KAM

&&

.HYDROLOGY...AS MENTIONED IN THE AFTERNOON DISCUSSION...THERE WAS A
DISTINCT LULL IN RAINFALL TODAY AND AMOUNTS THAT FELL WERE LESS THAN
FORECAST. RIVERS HAVE BEEN STEADY OR HAVE RISEN SLOWLY IN RESPONSE
TO EARLIER RAIN.

THE FRONT IN SOUTHERN BRITISH COLUMBIA IS STARTING TO SHIFT
SOUTHWARD INTO THE NORTH PART OF WESTERN WASHINGTON...AND RAIN RATES
ARE INCREASING A BIT IN THE OLYMPICS AND NORTH CASCADES. THE FRONT
WILL MOVE SOUTH TONIGHT AND FRIDAY THROUGH WASHINGTON...THEN MAKE
ITS WAY SOUTH OF THE STATE FRIDAY EVENING. MODELS ARE SIMILAR...
SHOWING ANOTHER 2-4 INCHES OF RAIN IN THE MOUNTAINS...AND OUR QPF
REFLECTS THIS CLOSELY. HEAVY RAIN SHOULD REDEVELOP THIS EVENING AND
SPREAD SOUTH OVERNIGHT. THE RAINIEST PERIOD IS 12Z-18Z FRIDAY WHEN
1-1.5 INCHES OF RAIN IS FORECAST OVER THE CASCADES OF SNOHOMISH AND
KING COUNTIES...WITH UP TO AN INCH OVER THE LOWLANDS OF THOSE
COUNTIES. RAIN SHOULD TAPER IN THE AFTERNOON AS THE AIR MASS COOLS
AND DRIES FROM THE NORTH.

THE US ARMY CORPS OF ENGINEERS HAS TAKEN CONTROL OF DAM OPERATION ON
THE SKAGIT AND BAKER RIVERS. AS A RESULT THE SKAGIT RIVER SHOULD
HAVE ONLY MINOR FLOODING ON BOTH THE CONCRETE AND MOUNT VERNON
REACHES. A FLOOD WARNING HAS BEEN POSTED FOR THE SKAGIT RIVER.

THE NOOKSACK RIVER IS ALSO FORECAST TO REACH FLOOD STAGE AT NORTH
CEDARVILLE AND FERNDALE. HOWEVER THE LACK OF HEAVY RAIN TODAY WILL
DELAY ANY FLOODING UNTIL LATE TONIGHT OR FRIDAY.

HEAVY RAIN WILL REACH THE BASINS OF RIVERS FLOWING OFF THE CASCADES
OF SNOHOMISH AND KING COUNTIES LATE TONIGHT AND CONTINUE INTO THE
DAY FRIDAY. A SHEAF OF RIVERS FROM THE STILLAGUAMISH SOUTH TO THE
PUYALLUP NEAR ORTING...INCLUDING THE SKYKOMISH...SNOQUALMIE...
TOLT...AND SNOHOMISH...COULD ALL REACH FLOOD STAGE FROM THIS SHORT
BUT INTENSE BURST OF HEAVY RAIN. ANY FLOODING ON THESE RIVERS IS
EXPECTED TO BE MINOR.

THE SOUTHERN TIER OF RIVERS APPEAR TO BE AT LESS RISK OF FLOODING.
IN THE MODELS THE FRONT SEEMS A BIT SPENT AS IT MOVES INTO THE
SOUTHERN COUNTIES...PIERCE AND LEWIS...AND RAINFALL MAY NOT BE AS
HEAVY AS IN THE NORTHERN COUNTIES. A FLOOD WATCH REMAINS IN EFFECT
FOR ALL COUNTIES FROM WHATCOM TO LEWIS...AS WELL AS MASON COUNTY.

SPEAKING OF MASON COUNTY...THE SKOKOMISH RIVER IS ABOVE FLOOD STAGE
AND WILL LIKELY REMAIN NEAR OR ABOVE FLOOD STAGE THROUGH FRIDAY
NIGHT. THE FLOOD WARNING THERE REMAINS IN EFFECT. BURKE/MCDONNAL

&&

.AVIATION...MOIST WESTERLY FLOW CONTINUES TO IMPACT WESTERN WA
TONIGHT WITH RAIN ACROSS THE REGION. GUSTY SOUTH WINDS EXPECTED AT
THE SURFACE. RAIN WILL INCREASE IN COVERAGE AND INTENSITY LATE
TONIGHT THROUGH FRI MORNING AS A COLD FRONT SHIFTS SOUTH THROUGH THE
REGION. MVFR CIGS ARE LIKELY. N/NE FRASER RIVER OUTFLOW WINDS WILL
DEVELOP FRI NIGHT AFFECTING KBLI. A COOL AIR MASS WILL SETTLE OVER
THE REGION SAT MORNING AS AN UPPER LEVEL TROUGH TRACKS OVERHEAD.
THIS SYSTEM MAY BRING LOW LEVEL SNOW TO THE REGION IN THE INTERIOR
AND STRAIT OF JUAN DE FUCA. THIS SYSTEM WILL EXIT SAT AFTERNOON OR
EVENING FOR DRY WEATHER. 33

KSEA...LIGHT RAIN CONTINUES ACROSS THE REGION TONIGHT...THEN
INCREASES 12-18Z FRI AS A COLD FRONT SHIFTS SOUTH THROUGH THE AREA.
MVFR CONDITIONS ARE LIKELY. THIS FRONT WILL ALSO BRING A WIND SHIFT
WITH WINDS BECOMING NLY BY 18Z. LATE FRIDAY NIGHT INTO
SATURDAY...THERE IS A CHANCE FOR SNOW AT SEA-TAC WITH MODIFIED
ARCTIC AIR IN THE AREA. AT THIS POINT WE ARE LOOKING AT
ACCUMULATIONS OF AN INCH OR LESS. 33

&&

.MARINE...STRONG SOUTHERLY WINDS WILL CONTINUE OVER THE WATERS
TONIGHT AS A COLD FRONT OVER SOUTHERN B.C. SHIFTS SOUTH INTO WESTERN
WA. SMALL CRAFT ADVISORIES ARE IN EFFECT FOR ALL WATERS. THIS FRONT
WILL PUSH SOUTH THROUGH THE AREA FRI AFTERNOON...WITH WINDS
SWITCHING TO NORTHERLY IN THE INTERIOR. FRASER RIVER OUTFLOW WINDS
WILL DEVELOP BEHIND THIS FRONT LATE FRI NIGHT AND SAT AS STRONG HIGH
PRES OVER INTERIOR B.C. SAGS SOUTH. A GALE WATCH IS IN EFFECT FOR
THE NORTHERN INLAND WATERS AND EAST ENTRANCE OF JUAN DE FUCA.
OFFSHORE FLOW WILL PREVAIL EARLY NEXT WEEK WITH HIGH PRES EAST OF
THE CASCADES. 33

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...FLOOD WATCHES AND WARNINGS IN EFFECT FOR PORTIONS OF
     WESTERN WASHINGTON.

PZ...GALE WATCH NORTHERN INLAND WATERS AND EAST ENTRANCE STRAIT OF
     JUAN DE FUCA FOR FRIDAY NIGHT AND SATURDAY.
     SMALL CRAFT ADVISORY ALL WATERS.
     SMALL CRAFT ADVISORY GRAYS HARBOR BAR FOR ROUGH 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 280514
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
910 PM PST THU NOV 27 2014

.SYNOPSIS...A COLD FRONT WILL MOVE SOUTH ACROSS WESTERN WA LATE
TONIGHT AND FRIDAY MORNING PRODUCING HEAVY RAIN OVER THE MOUNTAINS
AND OVER PARTS OF THE PUGET SOUND REGION. A CONVERGENCE ZONE WILL
CONTINUE OVER PUGET SOUND FRIDAY NIGHT...THEN ANOTHER COLD FRONT
WITH MODIFIED ARCTIC AIR WILL MOVE SOUTH THROUGH THE AREA LATE
FRIDAY NIGHT INTO SATURDAY MORNING. SOME SNOW OR RAIN AND SNOW MIXED
IS LIKELY TO OCCUR WITH THE CONVERGENCE ZONE AND ALONG THIS SECOND
FRONT. COOL NORTHWEST FLOW ALOFT WILL BRING MAINLY COOL AND DRY
WEATHER SUNDAY THROUGH EARLY NEXT WEEK.

&&

.SHORT TERM...VARIABILITY APPEARS TO BE THE BEST WORD TO DESCRIBE
THE SHORT TERM FORECAST. CURRENT RADAR SHOWS RAIN NOT QUITE AS
WIDESPREAD AS INITIALLY THOUGHT OR FORECAST...WITH PRECIP EAST OF
THE SOUND CONFINED PRIMARILY TO THE CASCADES. AS UPCOMING FRONT
STARTS TO MAKE ITS WAY INTO THE AREA OVERNIGHT TONIGHT AND INTO
TOMORROW...SHOULD SEE THAT HOLE START TO FILL IN. CURRENT IR
SATELLITE IMAGERY GIVES PAUSE TO THAT THOUGHT HOWEVER. IF FRONTAL
MOVEMENT ADHERES TO SOUTHEAST MOTION AS FORECAST...CLOUD LAYERS WILL
LOOK TO BE FAIRLY SHALLOW AND THUS WHILE RAIN REMAINS A FAIR
POSSIBILITY...MIGHT BE LESS THAN ADVERTISED. THROWING ANOTHER
HOWEVER IN THE MIX THOUGH IS THE CURRENT TREND IN SAID IR IMAGERY TO
SHOW SOME BUILDING IN CLOUDS. THUS...AT THIS TIME AM INCLINED TO
SIDE WITH THOUGHT THAT THINGS JUST GOT STARTED A BIT LATER THAN
PROGGED AND LEAVE INHERITED FORECAST INTACT.

MODELS REMAIN CONSISTENT WITH THE FORECAST FOR FRIDAY AND INTO
SATURDAY AS THE FRONT SLOWLY MAKES ITS WAY THROUGH WESTERN
WASHINGTON BY LATE FRIDAY MORNING AND PRODUCING RAIN FOR MOST
LOCATIONS FOR MUCH OF THE DAY. TEMPERATURES WILL FALL STEADILY
THROUGH THE DAY FRIDAY AFTER FROPA AS COLDER AIR STARTS TO MAKE ITS
WAY IN. SUFFICIENT MOISTURE IS EXPECTED TO LINGER AND COUPLED WITH A
CONVERGENCE ZONE STILL PRESENT IN CURRENT MODEL OUTPUT...CONDITIONS
STILL LOOK FAVORABLE FOR RAIN TO TRANSITION INTO MIXED PRECIPITATION
FRIDAY NIGHT AND LOWLAND SNOW FOR OVERNIGHT FRIDAY AND INTO SATURDAY
MORNING. A LOT OF THIS STILL DEPENDS ON TIMING OF FACTORS...AND AS
THE PREVIOUS PARAGRAPH OPENED...VARIABILITY HAS BEEN THE WATCH WORD
FOR THE FORECAST TONIGHT. THAT SAID...STILL OPTING TO PLAY SNOW
EVENT ON LOW END OF THINGS FOR NOW...WITH MOST LOWLAND LOCATIONS
THAT DO SEE FLAKES SEEING LESS THAN AN INCH. PASSING UPPER LEVEL
TROUGH SCOURS MOISTURE OUT QUICKLY BY LATE SATURDAY MORNING. THAT
AND SURFACE HIGH PRESSURE MOVING INTO SOUTHERN BRITISH COLUMBIA WILL
SET THE STAGE FOR COLDER TEMPERATURES THIS WEEKEND. ALSO OF NOTE
WITH THAT SURFACE HIGH WILL BE THE DEVELOPMENT OF FRASER OUTFLOW
WINDS. AT THIS TIME...HIGH WIND WATCH IS IN PLACE TO COVER TIME
FRAME FROM FRIDAY NIGHT INTO SATURDAY...MAINLY FOCUSING ON WESTERN
WHATCOM...COASTAL SKAGIT AND SAN JUANS...EVEN THOUGH WIND SPEEDS MAY
ONLY MAKE ADVISORY CRITERIA. ANOTHER MODEL RUN SHOULD BE ENOUGH TO
DECIDE WHETHER OR NOT TO UPGRADE.

STILL LOOKING CLEAR AND COLD FOR SUNDAY WITH TEMPERATURES SLOWLY
REBOUNDING MONDAY. SMR

.LONG TERM...FROM 408 PM DISCUSSION...ONLY MINOR CHANGES WERE MADE
TO THE LONG TERM FORECAST...MONDAY THROUGH THURSDAY. THE SET-UP HAS
A NORTHERN STREAM RIDGE OFFSHORE OVER THE NE PACIFIC...WITH COOL NW
FLOW ALOFT OVER W WA. ALSO IN THE PICTURE IS A SOUTHERN STREAM
CLOSED LOW W OF THE CA COAST. WASHINGTON APPEARS TO BE CONTESTED
TERRITORY BETWEEN THE NORTHERN AND SOUTHERN STREAMS WHICH MEANS
MODEL BATTLES TO DETERMINE WHICH STREAM WILL WIN OUT. THE ECMWF HAS
BEEN MORE OR LESS CONSISTENTLY KEEPING THE AREA UNDER THE COOLER
DRIER AND SUNNIER N STREAM THROUGH MID NEXT WEEK. THE GFS HAS BEEN
WOBBLING BETWEEN THE ECMWF SOLUTION AND A WETTER SOUTHERN STREAM
SOLUTION. FORECASTS CONTINUE TO FOLLOW THE ECMWF...BUT CONFIDENCE IS
ONLY MODERATE GIVEN THE MODEL CONFLICTS AND THE OVERALL DIFFICULTY
IN RESOLVING A PATTERN LIKE THIS. MODELS DO AGREE THAT A SHORTWAVE
TROUGH WILL MOVE SE ACROSS THE AREA ON MONDAY. THIS LOOKS DRY AT
THIS POINT BUT MORE CLOUDS AND POSSIBLY SOME LIGHT PRECIP MAY NEED
TO BE ADDED TO THE FORECAST IF MODEL SOLUTIONS CHANGE. KAM

&&

.HYDROLOGY...AS MENTIONED IN THE AFTERNOON DISCUSSION...THERE WAS A
DISTINCT LULL IN RAINFALL TODAY AND AMOUNTS THAT FELL WERE LESS THAN
FORECAST. RIVERS HAVE BEEN STEADY OR HAVE RISEN SLOWLY IN RESPONSE
TO EARLIER RAIN.

THE FRONT IN SOUTHERN BRITISH COLUMBIA IS STARTING TO SHIFT
SOUTHWARD INTO THE NORTH PART OF WESTERN WASHINGTON...AND RAIN RATES
ARE INCREASING A BIT IN THE OLYMPICS AND NORTH CASCADES. THE FRONT
WILL MOVE SOUTH TONIGHT AND FRIDAY THROUGH WASHINGTON...THEN MAKE
ITS WAY SOUTH OF THE STATE FRIDAY EVENING. MODELS ARE SIMILAR...
SHOWING ANOTHER 2-4 INCHES OF RAIN IN THE MOUNTAINS...AND OUR QPF
REFLECTS THIS CLOSELY. HEAVY RAIN SHOULD REDEVELOP THIS EVENING AND
SPREAD SOUTH OVERNIGHT. THE RAINIEST PERIOD IS 12Z-18Z FRIDAY WHEN
1-1.5 INCHES OF RAIN IS FORECAST OVER THE CASCADES OF SNOHOMISH AND
KING COUNTIES...WITH UP TO AN INCH OVER THE LOWLANDS OF THOSE
COUNTIES. RAIN SHOULD TAPER IN THE AFTERNOON AS THE AIR MASS COOLS
AND DRIES FROM THE NORTH.

THE US ARMY CORPS OF ENGINEERS HAS TAKEN CONTROL OF DAM OPERATION ON
THE SKAGIT AND BAKER RIVERS. AS A RESULT THE SKAGIT RIVER SHOULD
HAVE ONLY MINOR FLOODING ON BOTH THE CONCRETE AND MOUNT VERNON
REACHES. A FLOOD WARNING HAS BEEN POSTED FOR THE SKAGIT RIVER.

THE NOOKSACK RIVER IS ALSO FORECAST TO REACH FLOOD STAGE AT NORTH
CEDARVILLE AND FERNDALE. HOWEVER THE LACK OF HEAVY RAIN TODAY WILL
DELAY ANY FLOODING UNTIL LATE TONIGHT OR FRIDAY.

HEAVY RAIN WILL REACH THE BASINS OF RIVERS FLOWING OFF THE CASCADES
OF SNOHOMISH AND KING COUNTIES LATE TONIGHT AND CONTINUE INTO THE
DAY FRIDAY. A SHEAF OF RIVERS FROM THE STILLAGUAMISH SOUTH TO THE
PUYALLUP NEAR ORTING...INCLUDING THE SKYKOMISH...SNOQUALMIE...
TOLT...AND SNOHOMISH...COULD ALL REACH FLOOD STAGE FROM THIS SHORT
BUT INTENSE BURST OF HEAVY RAIN. ANY FLOODING ON THESE RIVERS IS
EXPECTED TO BE MINOR.

THE SOUTHERN TIER OF RIVERS APPEAR TO BE AT LESS RISK OF FLOODING.
IN THE MODELS THE FRONT SEEMS A BIT SPENT AS IT MOVES INTO THE
SOUTHERN COUNTIES...PIERCE AND LEWIS...AND RAINFALL MAY NOT BE AS
HEAVY AS IN THE NORTHERN COUNTIES. A FLOOD WATCH REMAINS IN EFFECT
FOR ALL COUNTIES FROM WHATCOM TO LEWIS...AS WELL AS MASON COUNTY.

SPEAKING OF MASON COUNTY...THE SKOKOMISH RIVER IS ABOVE FLOOD STAGE
AND WILL LIKELY REMAIN NEAR OR ABOVE FLOOD STAGE THROUGH FRIDAY
NIGHT. THE FLOOD WARNING THERE REMAINS IN EFFECT. BURKE/MCDONNAL

&&

.AVIATION...MOIST WESTERLY FLOW CONTINUES TO IMPACT WESTERN WA
TONIGHT WITH RAIN ACROSS THE REGION. GUSTY SOUTH WINDS EXPECTED AT
THE SURFACE. RAIN WILL INCREASE IN COVERAGE AND INTENSITY LATE
TONIGHT THROUGH FRI MORNING AS A COLD FRONT SHIFTS SOUTH THROUGH THE
REGION. MVFR CIGS ARE LIKELY. N/NE FRASER RIVER OUTFLOW WINDS WILL
DEVELOP FRI NIGHT AFFECTING KBLI. A COOL AIR MASS WILL SETTLE OVER
THE REGION SAT MORNING AS AN UPPER LEVEL TROUGH TRACKS OVERHEAD.
THIS SYSTEM MAY BRING LOW LEVEL SNOW TO THE REGION IN THE INTERIOR
AND STRAIT OF JUAN DE FUCA. THIS SYSTEM WILL EXIT SAT AFTERNOON OR
EVENING FOR DRY WEATHER. 33

KSEA...LIGHT RAIN CONTINUES ACROSS THE REGION TONIGHT...THEN
INCREASES 12-18Z FRI AS A COLD FRONT SHIFTS SOUTH THROUGH THE AREA.
MVFR CONDITIONS ARE LIKELY. THIS FRONT WILL ALSO BRING A WIND SHIFT
WITH WINDS BECOMING NLY BY 18Z. LATE FRIDAY NIGHT INTO
SATURDAY...THERE IS A CHANCE FOR SNOW AT SEA-TAC WITH MODIFIED
ARCTIC AIR IN THE AREA. AT THIS POINT WE ARE LOOKING AT
ACCUMULATIONS OF AN INCH OR LESS. 33

&&

.MARINE...STRONG SOUTHERLY WINDS WILL CONTINUE OVER THE WATERS
TONIGHT AS A COLD FRONT OVER SOUTHERN B.C. SHIFTS SOUTH INTO WESTERN
WA. SMALL CRAFT ADVISORIES ARE IN EFFECT FOR ALL WATERS. THIS FRONT
WILL PUSH SOUTH THROUGH THE AREA FRI AFTERNOON...WITH WINDS
SWITCHING TO NORTHERLY IN THE INTERIOR. FRASER RIVER OUTFLOW WINDS
WILL DEVELOP BEHIND THIS FRONT LATE FRI NIGHT AND SAT AS STRONG HIGH
PRES OVER INTERIOR B.C. SAGS SOUTH. A GALE WATCH IS IN EFFECT FOR
THE NORTHERN INLAND WATERS AND EAST ENTRANCE OF JUAN DE FUCA.
OFFSHORE FLOW WILL PREVAIL EARLY NEXT WEEK WITH HIGH PRES EAST OF
THE CASCADES. 33

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...FLOOD WATCHES AND WARNINGS IN EFFECT FOR PORTIONS OF
     WESTERN WASHINGTON.

PZ...GALE WATCH NORTHERN INLAND WATERS AND EAST ENTRANCE STRAIT OF
     JUAN DE FUCA FOR FRIDAY NIGHT AND SATURDAY.
     SMALL CRAFT ADVISORY ALL WATERS.
     SMALL CRAFT ADVISORY GRAYS HARBOR BAR FOR ROUGH BAR.

&&

$$

WWW.WEATHER.GOV/SEATTLE

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






  [top]

000
FXUS66 KPQR 280505
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
843 PM PST THU NOV 27 2014

.SYNOPSIS...A FRONTAL ZONE REMAINS STALLED OVER WESTERN OREGON AND
WILL REMAIN SO THROUGH FRIDAY. ANOTHER UPPER LEVEL DISTURBANCE WILL
RIDE ALONG THE FRONT LATER TONIGHT AND EARLY FRIDAY...LIKELY CAUSING
RAIN TO FILL IN AGAIN ACROSS THE FORECAST AREA. A SHARP COLD FRONT
WILL MOVE SOUTHEAST ACROSS THE REGION FRIDAY NIGHT. THERE WILL BE A
SHARP TEMPERATURE DROP WITH THE PASSAGE OF THIS COLD FRONT...WITH
SNOW LEVELS QUICKLY LOWERING OVERNIGHT. MIXED RAIN/SNOW SHOWERS ARE
EXPECTED IN THE LOWLANDS SATURDAY AS AN UPPER TROUGH PASSES THROUGH.
SNOW ACCUMULATIONS SHOULD BE LIMITED TO THE HILLS AND ABOVE. HIGH
PRESSURE WILL SETTLE IN EAST OF THE CASCADES SATURDAY NIGHT AND
SUNDAY... BRINGING STRONG EAST WINDS THROUGH THE GORGE AND ACROSS THE
PORTLAND METRO AREA. A SYSTEM COMING UP FROM THE SOUTH MAY ATTEMPT TO
SPREAD MOISTURE UP OVER THE COLD AIR EARLY NEXT WEEK... BUT AT THIS
POINT IT APPEARS MOST PRECIPITATION WILL STAY SOUTH OF OUR FORECAST
AREA.

&&

.SHORT TERM...TONIGHT THROUGH SUNDAY...IT IS A MILD AND RAINY NIGHT.
THIS KIND OF WEATHER CONTINUES FOR ANOTHER DAY THEN MORE WINTER LIKE
WEATHER.

PATTERN HAS CHANGED LITTLE TODAY WITH ONE STALLED FRONT OVER SW
OREGON AND NORTHERN CALIFORNIA BRINGING STEADY RAIN ACROSS LANE AND
LINN COUNTIES.NORTH OF THAT MORE SCATTERED SHOWERS CONTINUE BUT
WITH DECENT SW FLOW IN THE MID LEVELS THE OREGON CASCADE ZONES
ACCUMULATED AROUND 0.25 TO 0.5 INCH OVER THE PAST 6 HOURS. THE COAST
RANGE HAD ABOUT HALF THAT. FURTHER NORTH OVER WESTERN WA ANOTHER
FRONT IS SLOWLY MOVING TO THE SOUTH.  THIS FRONT BECOMES DOMINANT
OVERNIGHT AND FRI THEN SLIDES INTO SW WASHINGTON AND NW OREGON FRI
AFTERNOON AND NIGHT AND WILL USHER IN THE COLDER WEATHER.  MODELS
INDICATE THIS WILL BE A SHARP FRONT. 00Z NAM AND GFS SHOWS TIGHT
THICKNESS/TEMPERATURE PACKING UP TO 700 MB. NAM FRONTOGENSIS IS
STRONG UP THROUGH 850 MB. THIS WOULD INDICATE DECENT LIFT AS THE
FRONT MOVES THROUGH. MODEL QPF AMOUNTS LOOKED TOO HIGH PREVIOUSLY
THROUGH FRIDAY BUT LOOK MORE REASONABLE NOW.  SO HAVE UPDATED QPF
AMOUNTS TONIGHT AND FRI.


PREVIOUS DISCUSSION...
12Z/18Z NAM BUFR SOUNDINGS SUGGEST SOME WEAK MOIST/CONDITIONAL
INSTABILITY AHEAD OF THE FRONT FRIDAY. WOULD NOT BE SURPRISED TO SEE
A COUPLE STRAY LIGHTNING STRIKES ALONG AND AHEAD OF THE FRONT...
ESPECIALLY CONSIDERING THE STRONG FRONTOGENETICAL LIFT ASSOCIATED
WITH THE FRONT. HOWEVER...INSTABILITY IS EXTREMELY MARGINAL SO WE
DECIDED TO LEAVE IT OUT OF THE FORECAST AT THIS POINT...CHANCES ARE
PROBABLY AROUND 5-10 PERCENT FOR ANY GIVEN LOCATION.

SNOW LEVELS ARE PRESENTLY VERY HIGH...WITH TIMBERLINE WEBCAMS SHOWING
RAIN AS HIGH AS 6000-7000 FT ELEVATION. IT WILL BE A MUCH DIFFERENT
STORY FRI NIGHT AS SNOW LEVELS RAPIDLY LOWER BEHIND THE FRONT. 12Z
ECMWF SHOWS 925 MB TEMPS CRASHING FROM +9 DEG C LATE FRI AFTERNOON TO
-1 DEG C SIX HOURS LATER. BY OUR STANDARDS...THAT IS A FAIRLY
IMPRESSIVE DROP. AT THIS POINT...MOST MODEL SOUNDINGS SEEM TO SUPPORT
SOME WET SNOWFLAKES REACHING THE NORTH COAST AND VALLEY FLOOR BY
SATURDAY MORNING. SHALLOW INSTABILITY CONTINUES THROUGH THE DAY
SATURDAY A POSITIVELY TILTED UPPER TROUGH MOVES THROUGH THE PAC NW.
GIVEN 850 MB TEMPS IN THE -7 TO -8 DEG C RANGE...HEAVIER SHOWERS MAY
STILL PRODUCE A MIX OF RAIN AND WET SNOW OR GRAUPEL DOWN TO THE
VALLEY FLOOR. HOWEVER IT APPEARS ACCUMULATING SNOW WILL BE LIMITED TO
ELEVATIONS ABOVE 500 TO 1000 FT...WITH ACCUMULATIONS INCREASING WITH
ELEVATION ABOVE THAT. THE HIGHER WEST HILLS OF PORTLAND AND SOME
HIGHER ELEVATION SUBURBS MAY SEE A SLUSHY INCH OR TWO OF ACCUMULATION
BY THE TIME ALL IS SAID AND DONE. SNOW LEVELS WILL BE A LITTLE HIGHER
FURTHER TO THE SOUTH.

HIGH PRESSURE WILL THEN BUILD IN SATURDAY NIGHT...BECOMING MORE
CENTERED EAST OF THE CASCADES BY SUNDAY. OFFSHORE PRESSURE GRADIENTS
WILL INCREASE SUNDAY...WITH SOME HIGH RESOLUTION MODELS SUGGESTING
KTTD-KDLS PRESSURE GRADIENTS WILL GET TO -10 MB OR POSSIBLY STRONGER.
THIS WOULD BE ENOUGH FOR EAST WINDS GUSTING 60-70 MPH THROUGH THE
GORGE...AND 40-45 MPH GUSTS IN THE PORTLAND METRO AREA. IF MODELS
CONTINUE THIS TREND...A WIND ADVISORY MAY EVENTUALLY BE NEEDED FOR
THE PORTLAND/VANCOUVER METRO. TEMPERATURES WILL BE WELL BELOW NORMAL
SAT/SUN...WITH HIGHS STUCK IN THE 30S IN AND NEAR THE GORGE AND 40S
MOST LOWLAND LOCATIONS ELSEWHERE.  WEAGLE

.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY...STRONG EAST WINDS SHOULD
EASE SOMEWHAT MONDAY AS A NORTHERN STREAM SYSTEM AND ASSOCIATED
WESTERLY FLOW ALOFT SHOULD ERODE THE HIGH PRESSURE CENTER EAST OF THE
CASCADES. THIS SHOULD CUT DOWN THE PRESSURE GRADIENT A BIT...THOUGH
SOME SORT OF EASTERLY FLOW SHOULD LINGER INSIDE THE GORGE. THERE IS A
LOT OF UNCERTAINTY IN REGARDS TO AN UPPER LEVEL LOW WHICH IS FORECAST
TO CUT OFF SOMEWHERE WEST OF CALIFORNIA SUNDAY. THE 12Z/18Z GFS HAVE
BEEN OUTLIERS IN COMPARISON TO THE LAST COUPLE RUNS OF THE ECMWF AND
THE 12Z CANADIAN MODEL...IN BRINGING A SIGNIFICANT BATCH OF
PRECIPITATION BACK NORTHWARD ACROSS OREGON SUN NIGHT/MONDAY THEN
HAVING IT LINGER FOR MUCH OF THE WEEK. MEANWHILE THE LAST COUPLE RUNS
OF THE ECMWF AND GEM KEEP US GENERALLY DRY THROUGH MIDWEEK...WITH
ANOTHER MODERATE SURGE OF EAST WIND TUE/WED. AFTER COLLABORATING WITH
NEIGHBORING OFFICES...THERE WAS A LARGE CONSENSUS THAT THE GFS
SOLUTION SHOULD BE DISCOUNTED FOR NOW...WITH OUR FORECAST FOLLOWING
MORE IN LINE WITH THE 12Z ECMWF SOLUTION. HOWEVER...IF MODELS START
TO TREND MORE TOWARD THE CURRENT GFS SOLUTION...WE MAY NEED TO
CONTEND WITH SNOW OR ICE FOR AT LEAST A PORTION OF THE COLUMBIA
GORGE.WEAGLE

&&

.AVIATION...FRONTAL BOUNDARY THE INTERIOR HAS REMAINED LARGELY
STATIONARY WITH MIX OF MVFR/VFR CIGS OVER THE INTERIOR THIS
EVENING AS LOWER CLOUD DECKS SOMEWHAT VARIABLE. MEANWHILE...MVFR
CONDITIONS CONTINUE FOR THE COASTAL AREAS. EXPECT BOUNDARY WITH
CONSIDERABLE LOW LEVEL MOISTURE TO REMAIN OVER THE REGION...SO
EXPECT TRENDING TOWARD INCREASINGLY MVFR CIGS OVER THE REGION
THROUGH THE OVERNIGHT PERIOD ALONG WITH INCREASING PRECIP
INTENSITY THROUGH FRI MORNING...AND HEAVIER RAIN MAY BRING VSBY
RESTRICTIONS TO THE 3-5 SM RANGE. A STRONG COLD FRONT APPROACH
THE REGION ON FRI...BRINGING A SHIFT TO NW WINDS TO NORTHERN
PORTION OF THE AREA AROUND 18Z FRI...REACHING THE SOUTHERN
PORTIONS BY 06Z SAT. HIGHER TERRAIN...SUCH AS THE OREGON COAST
RANGE...SW WA WILLAPA HILLS AND THE CASCADES WILL REMAIN OBSCURED
THROUGHOUT THE PERIOD.

KPDX AND APPROACHES...MIX OF MVFR/VFR CONTINUES AT THE TERMINAL
AND APPROACHES WITH CIGS 2500-3500 FT RANGE. LITTLE CHANGE
EXPECTED THROUGH FRI. S WINDS CONTINUE OVERNIGHT...SHIFTING TO
W-NW BEHIND THE FRONT BETWEEN 00Z-03Z SAT. CULLEN

&&

.MARINE...LATEST MODEL GUIDANCE AND OBSERVATIONS CONTINUE TO
SUGGEST GUSTS TO 25 KT AT TIMES THROUGH FRI MORNING. THERE MAY BE
SHORT PERIODS OF SUB-ADVISORY WIND SPEEDS THROUGH TONIGHT...BUT
BELIEVE THIS WILL BE THE EXCEPTION INSTEAD OF THE RULE. FAVOR THE
NAM/GFS WIND FIELD THROUGH SAT. A MORE ROBUST COLD FRONT WILL MOVE
SOUTH THROUGH THE COASTAL WATERS LATE FRI AND EARLY FRI EVENING
FOR CONTINUED SMALL CRAFT ADVISORY WIND. THE WIND WILL SWITCH TO
THE NORTHWEST BEHIND THIS FRONT. THE NORTHWEST WINDS WILL EASE ON
SATURDAY...THEN OFFSHORE GAP ENHANCED EAST WINDS WILL DEVELOP
SATURDAY NIGHT AND SUNDAY...LIKELY EXCEEDING SMALL CRAFT ADVISORY
CRITERIA. THE OFFSHORE WIND CONTINUES INTO EARLY NEXT WEEK...BUT
FAVOR THE ECMWF WIND PATTERN.

SEAS HOLDING IN THE 10 TO 13 FT RANGE AND WILL STAY THAT WAY THROUGH
EARLY FRIDAY...THEN CONTINUE TO HOVER AROUND 10 FT INTO
SATURDAY...BEFORE FALLING BELOW 10 FT BY SUNDAY. THE OFFSHORE
FLOW LATER THIS WEEKEND WILL DECREASE WAVE HEIGHT...BUT RESULT IN
VERY CHOPPY CONDITIONS. CULLEN/WEISHAAR

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 8 AM PST SATURDAY FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 8 AM PST SATURDAY
     FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR
OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 PM PST FRIDAY
     FOR COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60
NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 4 PM PST
FRIDAY.

&&

$$

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 280505
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
843 PM PST THU NOV 27 2014

.SYNOPSIS...A FRONTAL ZONE REMAINS STALLED OVER WESTERN OREGON AND
WILL REMAIN SO THROUGH FRIDAY. ANOTHER UPPER LEVEL DISTURBANCE WILL
RIDE ALONG THE FRONT LATER TONIGHT AND EARLY FRIDAY...LIKELY CAUSING
RAIN TO FILL IN AGAIN ACROSS THE FORECAST AREA. A SHARP COLD FRONT
WILL MOVE SOUTHEAST ACROSS THE REGION FRIDAY NIGHT. THERE WILL BE A
SHARP TEMPERATURE DROP WITH THE PASSAGE OF THIS COLD FRONT...WITH
SNOW LEVELS QUICKLY LOWERING OVERNIGHT. MIXED RAIN/SNOW SHOWERS ARE
EXPECTED IN THE LOWLANDS SATURDAY AS AN UPPER TROUGH PASSES THROUGH.
SNOW ACCUMULATIONS SHOULD BE LIMITED TO THE HILLS AND ABOVE. HIGH
PRESSURE WILL SETTLE IN EAST OF THE CASCADES SATURDAY NIGHT AND
SUNDAY... BRINGING STRONG EAST WINDS THROUGH THE GORGE AND ACROSS THE
PORTLAND METRO AREA. A SYSTEM COMING UP FROM THE SOUTH MAY ATTEMPT TO
SPREAD MOISTURE UP OVER THE COLD AIR EARLY NEXT WEEK... BUT AT THIS
POINT IT APPEARS MOST PRECIPITATION WILL STAY SOUTH OF OUR FORECAST
AREA.

&&

.SHORT TERM...TONIGHT THROUGH SUNDAY...IT IS A MILD AND RAINY NIGHT.
THIS KIND OF WEATHER CONTINUES FOR ANOTHER DAY THEN MORE WINTER LIKE
WEATHER.

PATTERN HAS CHANGED LITTLE TODAY WITH ONE STALLED FRONT OVER SW
OREGON AND NORTHERN CALIFORNIA BRINGING STEADY RAIN ACROSS LANE AND
LINN COUNTIES.NORTH OF THAT MORE SCATTERED SHOWERS CONTINUE BUT
WITH DECENT SW FLOW IN THE MID LEVELS THE OREGON CASCADE ZONES
ACCUMULATED AROUND 0.25 TO 0.5 INCH OVER THE PAST 6 HOURS. THE COAST
RANGE HAD ABOUT HALF THAT. FURTHER NORTH OVER WESTERN WA ANOTHER
FRONT IS SLOWLY MOVING TO THE SOUTH.  THIS FRONT BECOMES DOMINANT
OVERNIGHT AND FRI THEN SLIDES INTO SW WASHINGTON AND NW OREGON FRI
AFTERNOON AND NIGHT AND WILL USHER IN THE COLDER WEATHER.  MODELS
INDICATE THIS WILL BE A SHARP FRONT. 00Z NAM AND GFS SHOWS TIGHT
THICKNESS/TEMPERATURE PACKING UP TO 700 MB. NAM FRONTOGENSIS IS
STRONG UP THROUGH 850 MB. THIS WOULD INDICATE DECENT LIFT AS THE
FRONT MOVES THROUGH. MODEL QPF AMOUNTS LOOKED TOO HIGH PREVIOUSLY
THROUGH FRIDAY BUT LOOK MORE REASONABLE NOW.  SO HAVE UPDATED QPF
AMOUNTS TONIGHT AND FRI.


PREVIOUS DISCUSSION...
12Z/18Z NAM BUFR SOUNDINGS SUGGEST SOME WEAK MOIST/CONDITIONAL
INSTABILITY AHEAD OF THE FRONT FRIDAY. WOULD NOT BE SURPRISED TO SEE
A COUPLE STRAY LIGHTNING STRIKES ALONG AND AHEAD OF THE FRONT...
ESPECIALLY CONSIDERING THE STRONG FRONTOGENETICAL LIFT ASSOCIATED
WITH THE FRONT. HOWEVER...INSTABILITY IS EXTREMELY MARGINAL SO WE
DECIDED TO LEAVE IT OUT OF THE FORECAST AT THIS POINT...CHANCES ARE
PROBABLY AROUND 5-10 PERCENT FOR ANY GIVEN LOCATION.

SNOW LEVELS ARE PRESENTLY VERY HIGH...WITH TIMBERLINE WEBCAMS SHOWING
RAIN AS HIGH AS 6000-7000 FT ELEVATION. IT WILL BE A MUCH DIFFERENT
STORY FRI NIGHT AS SNOW LEVELS RAPIDLY LOWER BEHIND THE FRONT. 12Z
ECMWF SHOWS 925 MB TEMPS CRASHING FROM +9 DEG C LATE FRI AFTERNOON TO
-1 DEG C SIX HOURS LATER. BY OUR STANDARDS...THAT IS A FAIRLY
IMPRESSIVE DROP. AT THIS POINT...MOST MODEL SOUNDINGS SEEM TO SUPPORT
SOME WET SNOWFLAKES REACHING THE NORTH COAST AND VALLEY FLOOR BY
SATURDAY MORNING. SHALLOW INSTABILITY CONTINUES THROUGH THE DAY
SATURDAY A POSITIVELY TILTED UPPER TROUGH MOVES THROUGH THE PAC NW.
GIVEN 850 MB TEMPS IN THE -7 TO -8 DEG C RANGE...HEAVIER SHOWERS MAY
STILL PRODUCE A MIX OF RAIN AND WET SNOW OR GRAUPEL DOWN TO THE
VALLEY FLOOR. HOWEVER IT APPEARS ACCUMULATING SNOW WILL BE LIMITED TO
ELEVATIONS ABOVE 500 TO 1000 FT...WITH ACCUMULATIONS INCREASING WITH
ELEVATION ABOVE THAT. THE HIGHER WEST HILLS OF PORTLAND AND SOME
HIGHER ELEVATION SUBURBS MAY SEE A SLUSHY INCH OR TWO OF ACCUMULATION
BY THE TIME ALL IS SAID AND DONE. SNOW LEVELS WILL BE A LITTLE HIGHER
FURTHER TO THE SOUTH.

HIGH PRESSURE WILL THEN BUILD IN SATURDAY NIGHT...BECOMING MORE
CENTERED EAST OF THE CASCADES BY SUNDAY. OFFSHORE PRESSURE GRADIENTS
WILL INCREASE SUNDAY...WITH SOME HIGH RESOLUTION MODELS SUGGESTING
KTTD-KDLS PRESSURE GRADIENTS WILL GET TO -10 MB OR POSSIBLY STRONGER.
THIS WOULD BE ENOUGH FOR EAST WINDS GUSTING 60-70 MPH THROUGH THE
GORGE...AND 40-45 MPH GUSTS IN THE PORTLAND METRO AREA. IF MODELS
CONTINUE THIS TREND...A WIND ADVISORY MAY EVENTUALLY BE NEEDED FOR
THE PORTLAND/VANCOUVER METRO. TEMPERATURES WILL BE WELL BELOW NORMAL
SAT/SUN...WITH HIGHS STUCK IN THE 30S IN AND NEAR THE GORGE AND 40S
MOST LOWLAND LOCATIONS ELSEWHERE.  WEAGLE

.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY...STRONG EAST WINDS SHOULD
EASE SOMEWHAT MONDAY AS A NORTHERN STREAM SYSTEM AND ASSOCIATED
WESTERLY FLOW ALOFT SHOULD ERODE THE HIGH PRESSURE CENTER EAST OF THE
CASCADES. THIS SHOULD CUT DOWN THE PRESSURE GRADIENT A BIT...THOUGH
SOME SORT OF EASTERLY FLOW SHOULD LINGER INSIDE THE GORGE. THERE IS A
LOT OF UNCERTAINTY IN REGARDS TO AN UPPER LEVEL LOW WHICH IS FORECAST
TO CUT OFF SOMEWHERE WEST OF CALIFORNIA SUNDAY. THE 12Z/18Z GFS HAVE
BEEN OUTLIERS IN COMPARISON TO THE LAST COUPLE RUNS OF THE ECMWF AND
THE 12Z CANADIAN MODEL...IN BRINGING A SIGNIFICANT BATCH OF
PRECIPITATION BACK NORTHWARD ACROSS OREGON SUN NIGHT/MONDAY THEN
HAVING IT LINGER FOR MUCH OF THE WEEK. MEANWHILE THE LAST COUPLE RUNS
OF THE ECMWF AND GEM KEEP US GENERALLY DRY THROUGH MIDWEEK...WITH
ANOTHER MODERATE SURGE OF EAST WIND TUE/WED. AFTER COLLABORATING WITH
NEIGHBORING OFFICES...THERE WAS A LARGE CONSENSUS THAT THE GFS
SOLUTION SHOULD BE DISCOUNTED FOR NOW...WITH OUR FORECAST FOLLOWING
MORE IN LINE WITH THE 12Z ECMWF SOLUTION. HOWEVER...IF MODELS START
TO TREND MORE TOWARD THE CURRENT GFS SOLUTION...WE MAY NEED TO
CONTEND WITH SNOW OR ICE FOR AT LEAST A PORTION OF THE COLUMBIA
GORGE.WEAGLE

&&

.AVIATION...FRONTAL BOUNDARY THE INTERIOR HAS REMAINED LARGELY
STATIONARY WITH MIX OF MVFR/VFR CIGS OVER THE INTERIOR THIS
EVENING AS LOWER CLOUD DECKS SOMEWHAT VARIABLE. MEANWHILE...MVFR
CONDITIONS CONTINUE FOR THE COASTAL AREAS. EXPECT BOUNDARY WITH
CONSIDERABLE LOW LEVEL MOISTURE TO REMAIN OVER THE REGION...SO
EXPECT TRENDING TOWARD INCREASINGLY MVFR CIGS OVER THE REGION
THROUGH THE OVERNIGHT PERIOD ALONG WITH INCREASING PRECIP
INTENSITY THROUGH FRI MORNING...AND HEAVIER RAIN MAY BRING VSBY
RESTRICTIONS TO THE 3-5 SM RANGE. A STRONG COLD FRONT APPROACH
THE REGION ON FRI...BRINGING A SHIFT TO NW WINDS TO NORTHERN
PORTION OF THE AREA AROUND 18Z FRI...REACHING THE SOUTHERN
PORTIONS BY 06Z SAT. HIGHER TERRAIN...SUCH AS THE OREGON COAST
RANGE...SW WA WILLAPA HILLS AND THE CASCADES WILL REMAIN OBSCURED
THROUGHOUT THE PERIOD.

KPDX AND APPROACHES...MIX OF MVFR/VFR CONTINUES AT THE TERMINAL
AND APPROACHES WITH CIGS 2500-3500 FT RANGE. LITTLE CHANGE
EXPECTED THROUGH FRI. S WINDS CONTINUE OVERNIGHT...SHIFTING TO
W-NW BEHIND THE FRONT BETWEEN 00Z-03Z SAT. CULLEN

&&

.MARINE...LATEST MODEL GUIDANCE AND OBSERVATIONS CONTINUE TO
SUGGEST GUSTS TO 25 KT AT TIMES THROUGH FRI MORNING. THERE MAY BE
SHORT PERIODS OF SUB-ADVISORY WIND SPEEDS THROUGH TONIGHT...BUT
BELIEVE THIS WILL BE THE EXCEPTION INSTEAD OF THE RULE. FAVOR THE
NAM/GFS WIND FIELD THROUGH SAT. A MORE ROBUST COLD FRONT WILL MOVE
SOUTH THROUGH THE COASTAL WATERS LATE FRI AND EARLY FRI EVENING
FOR CONTINUED SMALL CRAFT ADVISORY WIND. THE WIND WILL SWITCH TO
THE NORTHWEST BEHIND THIS FRONT. THE NORTHWEST WINDS WILL EASE ON
SATURDAY...THEN OFFSHORE GAP ENHANCED EAST WINDS WILL DEVELOP
SATURDAY NIGHT AND SUNDAY...LIKELY EXCEEDING SMALL CRAFT ADVISORY
CRITERIA. THE OFFSHORE WIND CONTINUES INTO EARLY NEXT WEEK...BUT
FAVOR THE ECMWF WIND PATTERN.

SEAS HOLDING IN THE 10 TO 13 FT RANGE AND WILL STAY THAT WAY THROUGH
EARLY FRIDAY...THEN CONTINUE TO HOVER AROUND 10 FT INTO
SATURDAY...BEFORE FALLING BELOW 10 FT BY SUNDAY. THE OFFSHORE
FLOW LATER THIS WEEKEND WILL DECREASE WAVE HEIGHT...BUT RESULT IN
VERY CHOPPY CONDITIONS. CULLEN/WEISHAAR

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 8 AM PST SATURDAY FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 8 AM PST SATURDAY
     FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR
OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 PM PST FRIDAY
     FOR COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60
NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 4 PM PST
FRIDAY.

&&

$$

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 280505
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
843 PM PST THU NOV 27 2014

.SYNOPSIS...A FRONTAL ZONE REMAINS STALLED OVER WESTERN OREGON AND
WILL REMAIN SO THROUGH FRIDAY. ANOTHER UPPER LEVEL DISTURBANCE WILL
RIDE ALONG THE FRONT LATER TONIGHT AND EARLY FRIDAY...LIKELY CAUSING
RAIN TO FILL IN AGAIN ACROSS THE FORECAST AREA. A SHARP COLD FRONT
WILL MOVE SOUTHEAST ACROSS THE REGION FRIDAY NIGHT. THERE WILL BE A
SHARP TEMPERATURE DROP WITH THE PASSAGE OF THIS COLD FRONT...WITH
SNOW LEVELS QUICKLY LOWERING OVERNIGHT. MIXED RAIN/SNOW SHOWERS ARE
EXPECTED IN THE LOWLANDS SATURDAY AS AN UPPER TROUGH PASSES THROUGH.
SNOW ACCUMULATIONS SHOULD BE LIMITED TO THE HILLS AND ABOVE. HIGH
PRESSURE WILL SETTLE IN EAST OF THE CASCADES SATURDAY NIGHT AND
SUNDAY... BRINGING STRONG EAST WINDS THROUGH THE GORGE AND ACROSS THE
PORTLAND METRO AREA. A SYSTEM COMING UP FROM THE SOUTH MAY ATTEMPT TO
SPREAD MOISTURE UP OVER THE COLD AIR EARLY NEXT WEEK... BUT AT THIS
POINT IT APPEARS MOST PRECIPITATION WILL STAY SOUTH OF OUR FORECAST
AREA.

&&

.SHORT TERM...TONIGHT THROUGH SUNDAY...IT IS A MILD AND RAINY NIGHT.
THIS KIND OF WEATHER CONTINUES FOR ANOTHER DAY THEN MORE WINTER LIKE
WEATHER.

PATTERN HAS CHANGED LITTLE TODAY WITH ONE STALLED FRONT OVER SW
OREGON AND NORTHERN CALIFORNIA BRINGING STEADY RAIN ACROSS LANE AND
LINN COUNTIES.NORTH OF THAT MORE SCATTERED SHOWERS CONTINUE BUT
WITH DECENT SW FLOW IN THE MID LEVELS THE OREGON CASCADE ZONES
ACCUMULATED AROUND 0.25 TO 0.5 INCH OVER THE PAST 6 HOURS. THE COAST
RANGE HAD ABOUT HALF THAT. FURTHER NORTH OVER WESTERN WA ANOTHER
FRONT IS SLOWLY MOVING TO THE SOUTH.  THIS FRONT BECOMES DOMINANT
OVERNIGHT AND FRI THEN SLIDES INTO SW WASHINGTON AND NW OREGON FRI
AFTERNOON AND NIGHT AND WILL USHER IN THE COLDER WEATHER.  MODELS
INDICATE THIS WILL BE A SHARP FRONT. 00Z NAM AND GFS SHOWS TIGHT
THICKNESS/TEMPERATURE PACKING UP TO 700 MB. NAM FRONTOGENSIS IS
STRONG UP THROUGH 850 MB. THIS WOULD INDICATE DECENT LIFT AS THE
FRONT MOVES THROUGH. MODEL QPF AMOUNTS LOOKED TOO HIGH PREVIOUSLY
THROUGH FRIDAY BUT LOOK MORE REASONABLE NOW.  SO HAVE UPDATED QPF
AMOUNTS TONIGHT AND FRI.


PREVIOUS DISCUSSION...
12Z/18Z NAM BUFR SOUNDINGS SUGGEST SOME WEAK MOIST/CONDITIONAL
INSTABILITY AHEAD OF THE FRONT FRIDAY. WOULD NOT BE SURPRISED TO SEE
A COUPLE STRAY LIGHTNING STRIKES ALONG AND AHEAD OF THE FRONT...
ESPECIALLY CONSIDERING THE STRONG FRONTOGENETICAL LIFT ASSOCIATED
WITH THE FRONT. HOWEVER...INSTABILITY IS EXTREMELY MARGINAL SO WE
DECIDED TO LEAVE IT OUT OF THE FORECAST AT THIS POINT...CHANCES ARE
PROBABLY AROUND 5-10 PERCENT FOR ANY GIVEN LOCATION.

SNOW LEVELS ARE PRESENTLY VERY HIGH...WITH TIMBERLINE WEBCAMS SHOWING
RAIN AS HIGH AS 6000-7000 FT ELEVATION. IT WILL BE A MUCH DIFFERENT
STORY FRI NIGHT AS SNOW LEVELS RAPIDLY LOWER BEHIND THE FRONT. 12Z
ECMWF SHOWS 925 MB TEMPS CRASHING FROM +9 DEG C LATE FRI AFTERNOON TO
-1 DEG C SIX HOURS LATER. BY OUR STANDARDS...THAT IS A FAIRLY
IMPRESSIVE DROP. AT THIS POINT...MOST MODEL SOUNDINGS SEEM TO SUPPORT
SOME WET SNOWFLAKES REACHING THE NORTH COAST AND VALLEY FLOOR BY
SATURDAY MORNING. SHALLOW INSTABILITY CONTINUES THROUGH THE DAY
SATURDAY A POSITIVELY TILTED UPPER TROUGH MOVES THROUGH THE PAC NW.
GIVEN 850 MB TEMPS IN THE -7 TO -8 DEG C RANGE...HEAVIER SHOWERS MAY
STILL PRODUCE A MIX OF RAIN AND WET SNOW OR GRAUPEL DOWN TO THE
VALLEY FLOOR. HOWEVER IT APPEARS ACCUMULATING SNOW WILL BE LIMITED TO
ELEVATIONS ABOVE 500 TO 1000 FT...WITH ACCUMULATIONS INCREASING WITH
ELEVATION ABOVE THAT. THE HIGHER WEST HILLS OF PORTLAND AND SOME
HIGHER ELEVATION SUBURBS MAY SEE A SLUSHY INCH OR TWO OF ACCUMULATION
BY THE TIME ALL IS SAID AND DONE. SNOW LEVELS WILL BE A LITTLE HIGHER
FURTHER TO THE SOUTH.

HIGH PRESSURE WILL THEN BUILD IN SATURDAY NIGHT...BECOMING MORE
CENTERED EAST OF THE CASCADES BY SUNDAY. OFFSHORE PRESSURE GRADIENTS
WILL INCREASE SUNDAY...WITH SOME HIGH RESOLUTION MODELS SUGGESTING
KTTD-KDLS PRESSURE GRADIENTS WILL GET TO -10 MB OR POSSIBLY STRONGER.
THIS WOULD BE ENOUGH FOR EAST WINDS GUSTING 60-70 MPH THROUGH THE
GORGE...AND 40-45 MPH GUSTS IN THE PORTLAND METRO AREA. IF MODELS
CONTINUE THIS TREND...A WIND ADVISORY MAY EVENTUALLY BE NEEDED FOR
THE PORTLAND/VANCOUVER METRO. TEMPERATURES WILL BE WELL BELOW NORMAL
SAT/SUN...WITH HIGHS STUCK IN THE 30S IN AND NEAR THE GORGE AND 40S
MOST LOWLAND LOCATIONS ELSEWHERE.  WEAGLE

.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY...STRONG EAST WINDS SHOULD
EASE SOMEWHAT MONDAY AS A NORTHERN STREAM SYSTEM AND ASSOCIATED
WESTERLY FLOW ALOFT SHOULD ERODE THE HIGH PRESSURE CENTER EAST OF THE
CASCADES. THIS SHOULD CUT DOWN THE PRESSURE GRADIENT A BIT...THOUGH
SOME SORT OF EASTERLY FLOW SHOULD LINGER INSIDE THE GORGE. THERE IS A
LOT OF UNCERTAINTY IN REGARDS TO AN UPPER LEVEL LOW WHICH IS FORECAST
TO CUT OFF SOMEWHERE WEST OF CALIFORNIA SUNDAY. THE 12Z/18Z GFS HAVE
BEEN OUTLIERS IN COMPARISON TO THE LAST COUPLE RUNS OF THE ECMWF AND
THE 12Z CANADIAN MODEL...IN BRINGING A SIGNIFICANT BATCH OF
PRECIPITATION BACK NORTHWARD ACROSS OREGON SUN NIGHT/MONDAY THEN
HAVING IT LINGER FOR MUCH OF THE WEEK. MEANWHILE THE LAST COUPLE RUNS
OF THE ECMWF AND GEM KEEP US GENERALLY DRY THROUGH MIDWEEK...WITH
ANOTHER MODERATE SURGE OF EAST WIND TUE/WED. AFTER COLLABORATING WITH
NEIGHBORING OFFICES...THERE WAS A LARGE CONSENSUS THAT THE GFS
SOLUTION SHOULD BE DISCOUNTED FOR NOW...WITH OUR FORECAST FOLLOWING
MORE IN LINE WITH THE 12Z ECMWF SOLUTION. HOWEVER...IF MODELS START
TO TREND MORE TOWARD THE CURRENT GFS SOLUTION...WE MAY NEED TO
CONTEND WITH SNOW OR ICE FOR AT LEAST A PORTION OF THE COLUMBIA
GORGE.WEAGLE

&&

.AVIATION...FRONTAL BOUNDARY THE INTERIOR HAS REMAINED LARGELY
STATIONARY WITH MIX OF MVFR/VFR CIGS OVER THE INTERIOR THIS
EVENING AS LOWER CLOUD DECKS SOMEWHAT VARIABLE. MEANWHILE...MVFR
CONDITIONS CONTINUE FOR THE COASTAL AREAS. EXPECT BOUNDARY WITH
CONSIDERABLE LOW LEVEL MOISTURE TO REMAIN OVER THE REGION...SO
EXPECT TRENDING TOWARD INCREASINGLY MVFR CIGS OVER THE REGION
THROUGH THE OVERNIGHT PERIOD ALONG WITH INCREASING PRECIP
INTENSITY THROUGH FRI MORNING...AND HEAVIER RAIN MAY BRING VSBY
RESTRICTIONS TO THE 3-5 SM RANGE. A STRONG COLD FRONT APPROACH
THE REGION ON FRI...BRINGING A SHIFT TO NW WINDS TO NORTHERN
PORTION OF THE AREA AROUND 18Z FRI...REACHING THE SOUTHERN
PORTIONS BY 06Z SAT. HIGHER TERRAIN...SUCH AS THE OREGON COAST
RANGE...SW WA WILLAPA HILLS AND THE CASCADES WILL REMAIN OBSCURED
THROUGHOUT THE PERIOD.

KPDX AND APPROACHES...MIX OF MVFR/VFR CONTINUES AT THE TERMINAL
AND APPROACHES WITH CIGS 2500-3500 FT RANGE. LITTLE CHANGE
EXPECTED THROUGH FRI. S WINDS CONTINUE OVERNIGHT...SHIFTING TO
W-NW BEHIND THE FRONT BETWEEN 00Z-03Z SAT. CULLEN

&&

.MARINE...LATEST MODEL GUIDANCE AND OBSERVATIONS CONTINUE TO
SUGGEST GUSTS TO 25 KT AT TIMES THROUGH FRI MORNING. THERE MAY BE
SHORT PERIODS OF SUB-ADVISORY WIND SPEEDS THROUGH TONIGHT...BUT
BELIEVE THIS WILL BE THE EXCEPTION INSTEAD OF THE RULE. FAVOR THE
NAM/GFS WIND FIELD THROUGH SAT. A MORE ROBUST COLD FRONT WILL MOVE
SOUTH THROUGH THE COASTAL WATERS LATE FRI AND EARLY FRI EVENING
FOR CONTINUED SMALL CRAFT ADVISORY WIND. THE WIND WILL SWITCH TO
THE NORTHWEST BEHIND THIS FRONT. THE NORTHWEST WINDS WILL EASE ON
SATURDAY...THEN OFFSHORE GAP ENHANCED EAST WINDS WILL DEVELOP
SATURDAY NIGHT AND SUNDAY...LIKELY EXCEEDING SMALL CRAFT ADVISORY
CRITERIA. THE OFFSHORE WIND CONTINUES INTO EARLY NEXT WEEK...BUT
FAVOR THE ECMWF WIND PATTERN.

SEAS HOLDING IN THE 10 TO 13 FT RANGE AND WILL STAY THAT WAY THROUGH
EARLY FRIDAY...THEN CONTINUE TO HOVER AROUND 10 FT INTO
SATURDAY...BEFORE FALLING BELOW 10 FT BY SUNDAY. THE OFFSHORE
FLOW LATER THIS WEEKEND WILL DECREASE WAVE HEIGHT...BUT RESULT IN
VERY CHOPPY CONDITIONS. CULLEN/WEISHAAR

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 8 AM PST SATURDAY FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 8 AM PST SATURDAY
     FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR
OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 PM PST FRIDAY
     FOR COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60
NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 4 PM PST
FRIDAY.

&&

$$

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 KOTX 280034
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
418 PM PST THU NOV 27 2014

.SYNOPSIS...
A rainy and breezy weather pattern will envelope the region
tonight and Friday but snow levels will remain above pass levels
for motorists traveling on Friday. The arrival of a very cold and
windy arctic front Friday Night into Saturday will bring winter
driving conditions to the mountain passes and much cooler weather
for the weekend. Cold conditions with a few minor snow bearing
weather disturbances are expected as the new work week begins.

&&

.DISCUSSION...
Tonight and Friday...A somewhat complex flow regime is apparent on
satellite this afternoon. Two Pacific moisture feeds are
perceptible...one feeding into southwest Oregon with the northern
fringe of this feed seeping up into the southeastern
Washington/north Idaho zones and the second fetching into
Vancouver Isle. The southern fetch will provide a fuel source for
mainly spotty showers tonight and into Friday morning into the
Palouse area and the Shoshone County mountains. The northern feed
will slump southward and become better directed into the forecast
area tonight and sag further through the remainder of the forecast
area during the day Friday...driven through by an upper level
trough descending down the British Columbia coast and generating a
surface low under it`s dynamic foot over southern British
Columbia. This low is implied by the baroclinic leaf cloud shield
over central BC and Alberta.

Latest GFS and Nam and ECMWF models are in decent agreement in
evolving this flow regime. The BC surface low will move south and
enter the forecast area Friday morning...deepening as it
does...and move down the Washington/Idaho border. It will be
fueled by the northern deep moisture feed as it does. The presence
of this deepening surface low will help spread the precipitation
shield out into the basin...not just the mountains where the fast
westerly flow would imply a strong orographic component.

Thus the forecast for the next 24 hours will become increasingly
wet. All zones will be subject to light rain...with the best
chance for a significant period of rain on Friday over the
eastern and northern portions of the forecast area and over the
Cascades. Snow levels will remain between 5000 and 6000 feet until
the surface low passes to the south Friday night.

Winds will continue to be a dominant issue through Friday with
model soundings suggesting gust potential to 40 to 50 mph over the
exposed terrain of the eastern basin by Friday afternoon. A Wind
Advisory will be issued with the afternoon package for most of
the zones of the eastern basin. This breezy air mass will once
again promote mild temperatures for overnight lows tonight and
Friday high temps. /Fugazzi

Friday night through Sunday: This period will feature a big transition
from wet and mild weather toward cold and dry conditions. As this
transition occurs Friday night into Saturday, anticipate gusty
winds, periods of light to moderate precipitation (mainly in the
form of valley rain and high mountain snow), and concluding with
the potential for brief valley snow and potential for a few inches
within the eastern mountains.

* Synoptic Overview: Arctic air currently resides under the
  upper- level trof over Northern British Columbia. This low will
  pick up momentum during the next 24 hours then rapidly
  accelerate southward through the region Friday night into
  Saturday morning. The low will interact with a stalled frontal
  boundary draped along the International border promoting
  cyclogenesis (deepening surface low) and a strong surface low
  (990-994mb) deepens somewhere along the WA/ID border between
  I-90 and Canadian Border. Intense pressure gradients will setup
  on both sides of the low...first bringing a SW wind threat along
  its southern periphery Friday evening then along its northern
  periphery early Saturday morning into mid afternoon as the low
  sags south and dense arctic air mass floods in from Canada.

* Winds: Strong southwest winds are expected Friday evening and
  night across southeastern WA and into the ID Palouse as well as
  most mountain ridgetops associated with a strengthening low-
  level jet of 45-55 kts. High Res data from UW along with Bufkit
  data indicate the potential for sustained winds of 15-30 mph
  with gusts 35-55 mph for locations across the West Plains,
  Columbia Basin, Palouse, and foothills of the Blue Mtns.
  Mountain gusts from Mission Ridge to the Blue Mtns to the
  Central Panhandle Mtns will also be susceptible to gusts in
  excess of 50 mph. The strongest winds in these areas will be
  between Friday afternoon and Friday evening. Confidence high
  that the winds will exist roughly 2-4K feet above the surface
  but lower if these gusts will surface to valley floors. Data
  suggest a moderate threat and wind advisory has been issued.

* North winds will move into northern WA Friday evening and
  continue into Saturday. The strongest winds will be through the
  Okanogan Valley...spilling into the Waterville Plateau and
  western Basin. Winds of 15-30 mph with gusts to 45 mph are
  anticipated in these areas. With the air mass change so
  dramatic, I anticipate most north to south oriented valleys
  across Nrn WA will experience breezy conditions. Mountains,
  especially with a north aspect, will also feel gusty winds.

* Precipitation: Moderate to locally heavy precipitation will
  fall within the warm sector of the low bringing up to an inch of
  liquid to the mountains of Idaho and a general quarter to three
  quarters of an inch along the Cascade Crest and locations east
  of a line from Colville to Ritzville (outside the typical
  Cascade rain shadow) This will fall as rain below 6000 feet
  initially but snow levels will be crashing to valley floors with
  the arctic frontal passage Friday night. We don`t typically see
  much in the way of snow accumulations with these patterns as the
  deeper moisture gets shoved south before snow levels fall but a
  quick transition to snow will be possible just prior to
  precipitation ending with accumulations generally under an inch.
  A renewed threat for snow will come Saturday mainly focusing
  snow shower activity along the ID Panhandle and East Slopes. At
  this time, snow amounts with this activity will be light with up
  to a few inches in the mountains and less than an inch in the
  valleys. This will be very light and fluffy snow if it falls.

* Temperatures: High temperatures will be in the teens to 20s
  north to 20s and 30s south. Overnight lows will be manageable
  Saturday morning with winds keeping temperatures up somewhat but
  should be very cold Sunday morning single digits to teens)

* Impacts: Moderate to heavy rain and high mountain snow in Idaho Friday
  night. Rapid transition to freezing temperatures Saturday
  morning could result in flash freeze of rain on most roadways.
  Strong winds Friday evening into Saturday could result in
  scattered power outages and difficult travel conditions for high
  profile vehicles. Light snow accumulations possible in the ID
  Panhandle Friday night into Saturday morning. Very cold
  temperatures during the weekend. /sb

Sunday night through Thursday...Sunday night looks on mark with
continued dry and benign conditions as jet stream and associated
stalled front remains to the south and north/northeast flow at low
levels keeps cold air remaining in place. I have lower confidence
in the Monday/Monday night part of the forecast with GFS runs
showing the front/deformation zone to the south moving back
northward as a warm front of sorts that would overrun the cold air
in place allowing for a prolonged period of mostly snow to fall
from it roughly south of a line drawn from the Tri-Cities to Coeur
d` Alene. The ECMWF shows this feature remaining much further
south and not influencing the forecast area and instead shows a
general Northwest to Southeast flow on the east side of the
offshore ridge remaining in place which could steer a minor
shortwave or two down and influence far Southeast Washington and
Northern Idaho with snow but not to the degree or intensity of the
GFS solution. I, and neighboring offices, feel the ECMWF solution
may be the better way to go as it brings back a negatively tilted
ridge that slowly amplifies with an axis close to the coast. The
ridge off the coast solution is what we have had in place for most
of this fall and having it move back in place seems very
reasonable to me. The end result of the ridge moving back in place
would be a gradual slow warming trend as the ridge amplifies and
the axis moves closer to Eastern Washington and Northern Idaho.
Late Thursday the same favored ECMWF depicts an occluded frontal
zone oriented north to south with a well maintained moisture feed
sweeping up in a southwest to northeast trajectory and overrunning
the slightly warmer yet still cold air in place over the area
which should bring moderate snow to many a lowland and mountain
location mostly independent of elevation. The expectation is the
ridge will likely slow this solution and delay front passage until
Friday or Saturday so have not increased pops for Thursday. Stay
tuned to see if this solution holds true. /Pelatti

&&

.AVIATION...
18Z TAFS: Swift westerly flow in the mid levels of the atmosphere
will promote a rain shadow with generally dry conditions this
evening at all TAF sites. Breezy winds this afternoon will
decrease as the boundary layer decouples tonight but swift
southwest flow will above the boundary layer will promote LLWS
over the eastern TAF sites late tonight and early Friday morning.
VFR conditions are expected at all TAF sites except KEAT. At KEAT
where a moist low level air mass remains in a protected valley IFR
conditions are likely to return after 06-08Z and persist until
early Friday afternoon. Winds will increase in a showery air mass
Friday afternoon with gusts to 40 KTS possible at the KPUW and
KGEG TAF sites after 20Z.

NOTE: The VIS sensor at EAT is out of service so amendments to
VIS are not scheduled. the offending sensor replacement is on
order and may be returned to service by Saturday. /MJF


&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        41  50  26  27  10  22 /  30  70  60  20   0   0
Coeur d`Alene  41  49  29  29  11  23 /  40  80 100  20  10   0
Pullman        43  53  31  32  11  25 /  60  90 100  50  10   0
Lewiston       46  57  37  38  21  28 /  50  70  90  60  20   0
Colville       40  47  22  23   4  21 /  40  70  50  10   0   0
Sandpoint      38  45  26  27   8  20 /  70  90 100  20  10   0
Kellogg        39  44  29  30  10  21 /  70  90 100  50  10   0
Moses Lake     41  55  27  29   9  24 /  10  30  20  10   0   0
Wenatchee      41  49  29  30  13  23 /  20  30  10  10   0   0
Omak           37  46  17  19   1  19 /  20  30  10  10   0   0

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Wind Advisory from 1 PM Friday to Midnight PST Friday Night for
     Idaho Palouse.

WA...Wind Advisory from 1 PM Friday to Midnight PST Friday Night for
     Lower Garfield and Asotin Counties-Spokane Area-Upper
     Columbia Basin-Washington Palouse.

&&

$$




000
FXUS66 KOTX 280034
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
418 PM PST THU NOV 27 2014

.SYNOPSIS...
A rainy and breezy weather pattern will envelope the region
tonight and Friday but snow levels will remain above pass levels
for motorists traveling on Friday. The arrival of a very cold and
windy arctic front Friday Night into Saturday will bring winter
driving conditions to the mountain passes and much cooler weather
for the weekend. Cold conditions with a few minor snow bearing
weather disturbances are expected as the new work week begins.

&&

.DISCUSSION...
Tonight and Friday...A somewhat complex flow regime is apparent on
satellite this afternoon. Two Pacific moisture feeds are
perceptible...one feeding into southwest Oregon with the northern
fringe of this feed seeping up into the southeastern
Washington/north Idaho zones and the second fetching into
Vancouver Isle. The southern fetch will provide a fuel source for
mainly spotty showers tonight and into Friday morning into the
Palouse area and the Shoshone County mountains. The northern feed
will slump southward and become better directed into the forecast
area tonight and sag further through the remainder of the forecast
area during the day Friday...driven through by an upper level
trough descending down the British Columbia coast and generating a
surface low under it`s dynamic foot over southern British
Columbia. This low is implied by the baroclinic leaf cloud shield
over central BC and Alberta.

Latest GFS and Nam and ECMWF models are in decent agreement in
evolving this flow regime. The BC surface low will move south and
enter the forecast area Friday morning...deepening as it
does...and move down the Washington/Idaho border. It will be
fueled by the northern deep moisture feed as it does. The presence
of this deepening surface low will help spread the precipitation
shield out into the basin...not just the mountains where the fast
westerly flow would imply a strong orographic component.

Thus the forecast for the next 24 hours will become increasingly
wet. All zones will be subject to light rain...with the best
chance for a significant period of rain on Friday over the
eastern and northern portions of the forecast area and over the
Cascades. Snow levels will remain between 5000 and 6000 feet until
the surface low passes to the south Friday night.

Winds will continue to be a dominant issue through Friday with
model soundings suggesting gust potential to 40 to 50 mph over the
exposed terrain of the eastern basin by Friday afternoon. A Wind
Advisory will be issued with the afternoon package for most of
the zones of the eastern basin. This breezy air mass will once
again promote mild temperatures for overnight lows tonight and
Friday high temps. /Fugazzi

Friday night through Sunday: This period will feature a big transition
from wet and mild weather toward cold and dry conditions. As this
transition occurs Friday night into Saturday, anticipate gusty
winds, periods of light to moderate precipitation (mainly in the
form of valley rain and high mountain snow), and concluding with
the potential for brief valley snow and potential for a few inches
within the eastern mountains.

* Synoptic Overview: Arctic air currently resides under the
  upper- level trof over Northern British Columbia. This low will
  pick up momentum during the next 24 hours then rapidly
  accelerate southward through the region Friday night into
  Saturday morning. The low will interact with a stalled frontal
  boundary draped along the International border promoting
  cyclogenesis (deepening surface low) and a strong surface low
  (990-994mb) deepens somewhere along the WA/ID border between
  I-90 and Canadian Border. Intense pressure gradients will setup
  on both sides of the low...first bringing a SW wind threat along
  its southern periphery Friday evening then along its northern
  periphery early Saturday morning into mid afternoon as the low
  sags south and dense arctic air mass floods in from Canada.

* Winds: Strong southwest winds are expected Friday evening and
  night across southeastern WA and into the ID Palouse as well as
  most mountain ridgetops associated with a strengthening low-
  level jet of 45-55 kts. High Res data from UW along with Bufkit
  data indicate the potential for sustained winds of 15-30 mph
  with gusts 35-55 mph for locations across the West Plains,
  Columbia Basin, Palouse, and foothills of the Blue Mtns.
  Mountain gusts from Mission Ridge to the Blue Mtns to the
  Central Panhandle Mtns will also be susceptible to gusts in
  excess of 50 mph. The strongest winds in these areas will be
  between Friday afternoon and Friday evening. Confidence high
  that the winds will exist roughly 2-4K feet above the surface
  but lower if these gusts will surface to valley floors. Data
  suggest a moderate threat and wind advisory has been issued.

* North winds will move into northern WA Friday evening and
  continue into Saturday. The strongest winds will be through the
  Okanogan Valley...spilling into the Waterville Plateau and
  western Basin. Winds of 15-30 mph with gusts to 45 mph are
  anticipated in these areas. With the air mass change so
  dramatic, I anticipate most north to south oriented valleys
  across Nrn WA will experience breezy conditions. Mountains,
  especially with a north aspect, will also feel gusty winds.

* Precipitation: Moderate to locally heavy precipitation will
  fall within the warm sector of the low bringing up to an inch of
  liquid to the mountains of Idaho and a general quarter to three
  quarters of an inch along the Cascade Crest and locations east
  of a line from Colville to Ritzville (outside the typical
  Cascade rain shadow) This will fall as rain below 6000 feet
  initially but snow levels will be crashing to valley floors with
  the arctic frontal passage Friday night. We don`t typically see
  much in the way of snow accumulations with these patterns as the
  deeper moisture gets shoved south before snow levels fall but a
  quick transition to snow will be possible just prior to
  precipitation ending with accumulations generally under an inch.
  A renewed threat for snow will come Saturday mainly focusing
  snow shower activity along the ID Panhandle and East Slopes. At
  this time, snow amounts with this activity will be light with up
  to a few inches in the mountains and less than an inch in the
  valleys. This will be very light and fluffy snow if it falls.

* Temperatures: High temperatures will be in the teens to 20s
  north to 20s and 30s south. Overnight lows will be manageable
  Saturday morning with winds keeping temperatures up somewhat but
  should be very cold Sunday morning single digits to teens)

* Impacts: Moderate to heavy rain and high mountain snow in Idaho Friday
  night. Rapid transition to freezing temperatures Saturday
  morning could result in flash freeze of rain on most roadways.
  Strong winds Friday evening into Saturday could result in
  scattered power outages and difficult travel conditions for high
  profile vehicles. Light snow accumulations possible in the ID
  Panhandle Friday night into Saturday morning. Very cold
  temperatures during the weekend. /sb

Sunday night through Thursday...Sunday night looks on mark with
continued dry and benign conditions as jet stream and associated
stalled front remains to the south and north/northeast flow at low
levels keeps cold air remaining in place. I have lower confidence
in the Monday/Monday night part of the forecast with GFS runs
showing the front/deformation zone to the south moving back
northward as a warm front of sorts that would overrun the cold air
in place allowing for a prolonged period of mostly snow to fall
from it roughly south of a line drawn from the Tri-Cities to Coeur
d` Alene. The ECMWF shows this feature remaining much further
south and not influencing the forecast area and instead shows a
general Northwest to Southeast flow on the east side of the
offshore ridge remaining in place which could steer a minor
shortwave or two down and influence far Southeast Washington and
Northern Idaho with snow but not to the degree or intensity of the
GFS solution. I, and neighboring offices, feel the ECMWF solution
may be the better way to go as it brings back a negatively tilted
ridge that slowly amplifies with an axis close to the coast. The
ridge off the coast solution is what we have had in place for most
of this fall and having it move back in place seems very
reasonable to me. The end result of the ridge moving back in place
would be a gradual slow warming trend as the ridge amplifies and
the axis moves closer to Eastern Washington and Northern Idaho.
Late Thursday the same favored ECMWF depicts an occluded frontal
zone oriented north to south with a well maintained moisture feed
sweeping up in a southwest to northeast trajectory and overrunning
the slightly warmer yet still cold air in place over the area
which should bring moderate snow to many a lowland and mountain
location mostly independent of elevation. The expectation is the
ridge will likely slow this solution and delay front passage until
Friday or Saturday so have not increased pops for Thursday. Stay
tuned to see if this solution holds true. /Pelatti

&&

.AVIATION...
18Z TAFS: Swift westerly flow in the mid levels of the atmosphere
will promote a rain shadow with generally dry conditions this
evening at all TAF sites. Breezy winds this afternoon will
decrease as the boundary layer decouples tonight but swift
southwest flow will above the boundary layer will promote LLWS
over the eastern TAF sites late tonight and early Friday morning.
VFR conditions are expected at all TAF sites except KEAT. At KEAT
where a moist low level air mass remains in a protected valley IFR
conditions are likely to return after 06-08Z and persist until
early Friday afternoon. Winds will increase in a showery air mass
Friday afternoon with gusts to 40 KTS possible at the KPUW and
KGEG TAF sites after 20Z.

NOTE: The VIS sensor at EAT is out of service so amendments to
VIS are not scheduled. the offending sensor replacement is on
order and may be returned to service by Saturday. /MJF


&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        41  50  26  27  10  22 /  30  70  60  20   0   0
Coeur d`Alene  41  49  29  29  11  23 /  40  80 100  20  10   0
Pullman        43  53  31  32  11  25 /  60  90 100  50  10   0
Lewiston       46  57  37  38  21  28 /  50  70  90  60  20   0
Colville       40  47  22  23   4  21 /  40  70  50  10   0   0
Sandpoint      38  45  26  27   8  20 /  70  90 100  20  10   0
Kellogg        39  44  29  30  10  21 /  70  90 100  50  10   0
Moses Lake     41  55  27  29   9  24 /  10  30  20  10   0   0
Wenatchee      41  49  29  30  13  23 /  20  30  10  10   0   0
Omak           37  46  17  19   1  19 /  20  30  10  10   0   0

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Wind Advisory from 1 PM Friday to Midnight PST Friday Night for
     Idaho Palouse.

WA...Wind Advisory from 1 PM Friday to Midnight PST Friday Night for
     Lower Garfield and Asotin Counties-Spokane Area-Upper
     Columbia Basin-Washington Palouse.

&&

$$




000
FXUS66 KOTX 280034
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
418 PM PST THU NOV 27 2014

.SYNOPSIS...
A rainy and breezy weather pattern will envelope the region
tonight and Friday but snow levels will remain above pass levels
for motorists traveling on Friday. The arrival of a very cold and
windy arctic front Friday Night into Saturday will bring winter
driving conditions to the mountain passes and much cooler weather
for the weekend. Cold conditions with a few minor snow bearing
weather disturbances are expected as the new work week begins.

&&

.DISCUSSION...
Tonight and Friday...A somewhat complex flow regime is apparent on
satellite this afternoon. Two Pacific moisture feeds are
perceptible...one feeding into southwest Oregon with the northern
fringe of this feed seeping up into the southeastern
Washington/north Idaho zones and the second fetching into
Vancouver Isle. The southern fetch will provide a fuel source for
mainly spotty showers tonight and into Friday morning into the
Palouse area and the Shoshone County mountains. The northern feed
will slump southward and become better directed into the forecast
area tonight and sag further through the remainder of the forecast
area during the day Friday...driven through by an upper level
trough descending down the British Columbia coast and generating a
surface low under it`s dynamic foot over southern British
Columbia. This low is implied by the baroclinic leaf cloud shield
over central BC and Alberta.

Latest GFS and Nam and ECMWF models are in decent agreement in
evolving this flow regime. The BC surface low will move south and
enter the forecast area Friday morning...deepening as it
does...and move down the Washington/Idaho border. It will be
fueled by the northern deep moisture feed as it does. The presence
of this deepening surface low will help spread the precipitation
shield out into the basin...not just the mountains where the fast
westerly flow would imply a strong orographic component.

Thus the forecast for the next 24 hours will become increasingly
wet. All zones will be subject to light rain...with the best
chance for a significant period of rain on Friday over the
eastern and northern portions of the forecast area and over the
Cascades. Snow levels will remain between 5000 and 6000 feet until
the surface low passes to the south Friday night.

Winds will continue to be a dominant issue through Friday with
model soundings suggesting gust potential to 40 to 50 mph over the
exposed terrain of the eastern basin by Friday afternoon. A Wind
Advisory will be issued with the afternoon package for most of
the zones of the eastern basin. This breezy air mass will once
again promote mild temperatures for overnight lows tonight and
Friday high temps. /Fugazzi

Friday night through Sunday: This period will feature a big transition
from wet and mild weather toward cold and dry conditions. As this
transition occurs Friday night into Saturday, anticipate gusty
winds, periods of light to moderate precipitation (mainly in the
form of valley rain and high mountain snow), and concluding with
the potential for brief valley snow and potential for a few inches
within the eastern mountains.

* Synoptic Overview: Arctic air currently resides under the
  upper- level trof over Northern British Columbia. This low will
  pick up momentum during the next 24 hours then rapidly
  accelerate southward through the region Friday night into
  Saturday morning. The low will interact with a stalled frontal
  boundary draped along the International border promoting
  cyclogenesis (deepening surface low) and a strong surface low
  (990-994mb) deepens somewhere along the WA/ID border between
  I-90 and Canadian Border. Intense pressure gradients will setup
  on both sides of the low...first bringing a SW wind threat along
  its southern periphery Friday evening then along its northern
  periphery early Saturday morning into mid afternoon as the low
  sags south and dense arctic air mass floods in from Canada.

* Winds: Strong southwest winds are expected Friday evening and
  night across southeastern WA and into the ID Palouse as well as
  most mountain ridgetops associated with a strengthening low-
  level jet of 45-55 kts. High Res data from UW along with Bufkit
  data indicate the potential for sustained winds of 15-30 mph
  with gusts 35-55 mph for locations across the West Plains,
  Columbia Basin, Palouse, and foothills of the Blue Mtns.
  Mountain gusts from Mission Ridge to the Blue Mtns to the
  Central Panhandle Mtns will also be susceptible to gusts in
  excess of 50 mph. The strongest winds in these areas will be
  between Friday afternoon and Friday evening. Confidence high
  that the winds will exist roughly 2-4K feet above the surface
  but lower if these gusts will surface to valley floors. Data
  suggest a moderate threat and wind advisory has been issued.

* North winds will move into northern WA Friday evening and
  continue into Saturday. The strongest winds will be through the
  Okanogan Valley...spilling into the Waterville Plateau and
  western Basin. Winds of 15-30 mph with gusts to 45 mph are
  anticipated in these areas. With the air mass change so
  dramatic, I anticipate most north to south oriented valleys
  across Nrn WA will experience breezy conditions. Mountains,
  especially with a north aspect, will also feel gusty winds.

* Precipitation: Moderate to locally heavy precipitation will
  fall within the warm sector of the low bringing up to an inch of
  liquid to the mountains of Idaho and a general quarter to three
  quarters of an inch along the Cascade Crest and locations east
  of a line from Colville to Ritzville (outside the typical
  Cascade rain shadow) This will fall as rain below 6000 feet
  initially but snow levels will be crashing to valley floors with
  the arctic frontal passage Friday night. We don`t typically see
  much in the way of snow accumulations with these patterns as the
  deeper moisture gets shoved south before snow levels fall but a
  quick transition to snow will be possible just prior to
  precipitation ending with accumulations generally under an inch.
  A renewed threat for snow will come Saturday mainly focusing
  snow shower activity along the ID Panhandle and East Slopes. At
  this time, snow amounts with this activity will be light with up
  to a few inches in the mountains and less than an inch in the
  valleys. This will be very light and fluffy snow if it falls.

* Temperatures: High temperatures will be in the teens to 20s
  north to 20s and 30s south. Overnight lows will be manageable
  Saturday morning with winds keeping temperatures up somewhat but
  should be very cold Sunday morning single digits to teens)

* Impacts: Moderate to heavy rain and high mountain snow in Idaho Friday
  night. Rapid transition to freezing temperatures Saturday
  morning could result in flash freeze of rain on most roadways.
  Strong winds Friday evening into Saturday could result in
  scattered power outages and difficult travel conditions for high
  profile vehicles. Light snow accumulations possible in the ID
  Panhandle Friday night into Saturday morning. Very cold
  temperatures during the weekend. /sb

Sunday night through Thursday...Sunday night looks on mark with
continued dry and benign conditions as jet stream and associated
stalled front remains to the south and north/northeast flow at low
levels keeps cold air remaining in place. I have lower confidence
in the Monday/Monday night part of the forecast with GFS runs
showing the front/deformation zone to the south moving back
northward as a warm front of sorts that would overrun the cold air
in place allowing for a prolonged period of mostly snow to fall
from it roughly south of a line drawn from the Tri-Cities to Coeur
d` Alene. The ECMWF shows this feature remaining much further
south and not influencing the forecast area and instead shows a
general Northwest to Southeast flow on the east side of the
offshore ridge remaining in place which could steer a minor
shortwave or two down and influence far Southeast Washington and
Northern Idaho with snow but not to the degree or intensity of the
GFS solution. I, and neighboring offices, feel the ECMWF solution
may be the better way to go as it brings back a negatively tilted
ridge that slowly amplifies with an axis close to the coast. The
ridge off the coast solution is what we have had in place for most
of this fall and having it move back in place seems very
reasonable to me. The end result of the ridge moving back in place
would be a gradual slow warming trend as the ridge amplifies and
the axis moves closer to Eastern Washington and Northern Idaho.
Late Thursday the same favored ECMWF depicts an occluded frontal
zone oriented north to south with a well maintained moisture feed
sweeping up in a southwest to northeast trajectory and overrunning
the slightly warmer yet still cold air in place over the area
which should bring moderate snow to many a lowland and mountain
location mostly independent of elevation. The expectation is the
ridge will likely slow this solution and delay front passage until
Friday or Saturday so have not increased pops for Thursday. Stay
tuned to see if this solution holds true. /Pelatti

&&

.AVIATION...
18Z TAFS: Swift westerly flow in the mid levels of the atmosphere
will promote a rain shadow with generally dry conditions this
evening at all TAF sites. Breezy winds this afternoon will
decrease as the boundary layer decouples tonight but swift
southwest flow will above the boundary layer will promote LLWS
over the eastern TAF sites late tonight and early Friday morning.
VFR conditions are expected at all TAF sites except KEAT. At KEAT
where a moist low level air mass remains in a protected valley IFR
conditions are likely to return after 06-08Z and persist until
early Friday afternoon. Winds will increase in a showery air mass
Friday afternoon with gusts to 40 KTS possible at the KPUW and
KGEG TAF sites after 20Z.

NOTE: The VIS sensor at EAT is out of service so amendments to
VIS are not scheduled. the offending sensor replacement is on
order and may be returned to service by Saturday. /MJF


&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        41  50  26  27  10  22 /  30  70  60  20   0   0
Coeur d`Alene  41  49  29  29  11  23 /  40  80 100  20  10   0
Pullman        43  53  31  32  11  25 /  60  90 100  50  10   0
Lewiston       46  57  37  38  21  28 /  50  70  90  60  20   0
Colville       40  47  22  23   4  21 /  40  70  50  10   0   0
Sandpoint      38  45  26  27   8  20 /  70  90 100  20  10   0
Kellogg        39  44  29  30  10  21 /  70  90 100  50  10   0
Moses Lake     41  55  27  29   9  24 /  10  30  20  10   0   0
Wenatchee      41  49  29  30  13  23 /  20  30  10  10   0   0
Omak           37  46  17  19   1  19 /  20  30  10  10   0   0

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Wind Advisory from 1 PM Friday to Midnight PST Friday Night for
     Idaho Palouse.

WA...Wind Advisory from 1 PM Friday to Midnight PST Friday Night for
     Lower Garfield and Asotin Counties-Spokane Area-Upper
     Columbia Basin-Washington Palouse.

&&

$$




000
FXUS66 KOTX 280034
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
418 PM PST THU NOV 27 2014

.SYNOPSIS...
A rainy and breezy weather pattern will envelope the region
tonight and Friday but snow levels will remain above pass levels
for motorists traveling on Friday. The arrival of a very cold and
windy arctic front Friday Night into Saturday will bring winter
driving conditions to the mountain passes and much cooler weather
for the weekend. Cold conditions with a few minor snow bearing
weather disturbances are expected as the new work week begins.

&&

.DISCUSSION...
Tonight and Friday...A somewhat complex flow regime is apparent on
satellite this afternoon. Two Pacific moisture feeds are
perceptible...one feeding into southwest Oregon with the northern
fringe of this feed seeping up into the southeastern
Washington/north Idaho zones and the second fetching into
Vancouver Isle. The southern fetch will provide a fuel source for
mainly spotty showers tonight and into Friday morning into the
Palouse area and the Shoshone County mountains. The northern feed
will slump southward and become better directed into the forecast
area tonight and sag further through the remainder of the forecast
area during the day Friday...driven through by an upper level
trough descending down the British Columbia coast and generating a
surface low under it`s dynamic foot over southern British
Columbia. This low is implied by the baroclinic leaf cloud shield
over central BC and Alberta.

Latest GFS and Nam and ECMWF models are in decent agreement in
evolving this flow regime. The BC surface low will move south and
enter the forecast area Friday morning...deepening as it
does...and move down the Washington/Idaho border. It will be
fueled by the northern deep moisture feed as it does. The presence
of this deepening surface low will help spread the precipitation
shield out into the basin...not just the mountains where the fast
westerly flow would imply a strong orographic component.

Thus the forecast for the next 24 hours will become increasingly
wet. All zones will be subject to light rain...with the best
chance for a significant period of rain on Friday over the
eastern and northern portions of the forecast area and over the
Cascades. Snow levels will remain between 5000 and 6000 feet until
the surface low passes to the south Friday night.

Winds will continue to be a dominant issue through Friday with
model soundings suggesting gust potential to 40 to 50 mph over the
exposed terrain of the eastern basin by Friday afternoon. A Wind
Advisory will be issued with the afternoon package for most of
the zones of the eastern basin. This breezy air mass will once
again promote mild temperatures for overnight lows tonight and
Friday high temps. /Fugazzi

Friday night through Sunday: This period will feature a big transition
from wet and mild weather toward cold and dry conditions. As this
transition occurs Friday night into Saturday, anticipate gusty
winds, periods of light to moderate precipitation (mainly in the
form of valley rain and high mountain snow), and concluding with
the potential for brief valley snow and potential for a few inches
within the eastern mountains.

* Synoptic Overview: Arctic air currently resides under the
  upper- level trof over Northern British Columbia. This low will
  pick up momentum during the next 24 hours then rapidly
  accelerate southward through the region Friday night into
  Saturday morning. The low will interact with a stalled frontal
  boundary draped along the International border promoting
  cyclogenesis (deepening surface low) and a strong surface low
  (990-994mb) deepens somewhere along the WA/ID border between
  I-90 and Canadian Border. Intense pressure gradients will setup
  on both sides of the low...first bringing a SW wind threat along
  its southern periphery Friday evening then along its northern
  periphery early Saturday morning into mid afternoon as the low
  sags south and dense arctic air mass floods in from Canada.

* Winds: Strong southwest winds are expected Friday evening and
  night across southeastern WA and into the ID Palouse as well as
  most mountain ridgetops associated with a strengthening low-
  level jet of 45-55 kts. High Res data from UW along with Bufkit
  data indicate the potential for sustained winds of 15-30 mph
  with gusts 35-55 mph for locations across the West Plains,
  Columbia Basin, Palouse, and foothills of the Blue Mtns.
  Mountain gusts from Mission Ridge to the Blue Mtns to the
  Central Panhandle Mtns will also be susceptible to gusts in
  excess of 50 mph. The strongest winds in these areas will be
  between Friday afternoon and Friday evening. Confidence high
  that the winds will exist roughly 2-4K feet above the surface
  but lower if these gusts will surface to valley floors. Data
  suggest a moderate threat and wind advisory has been issued.

* North winds will move into northern WA Friday evening and
  continue into Saturday. The strongest winds will be through the
  Okanogan Valley...spilling into the Waterville Plateau and
  western Basin. Winds of 15-30 mph with gusts to 45 mph are
  anticipated in these areas. With the air mass change so
  dramatic, I anticipate most north to south oriented valleys
  across Nrn WA will experience breezy conditions. Mountains,
  especially with a north aspect, will also feel gusty winds.

* Precipitation: Moderate to locally heavy precipitation will
  fall within the warm sector of the low bringing up to an inch of
  liquid to the mountains of Idaho and a general quarter to three
  quarters of an inch along the Cascade Crest and locations east
  of a line from Colville to Ritzville (outside the typical
  Cascade rain shadow) This will fall as rain below 6000 feet
  initially but snow levels will be crashing to valley floors with
  the arctic frontal passage Friday night. We don`t typically see
  much in the way of snow accumulations with these patterns as the
  deeper moisture gets shoved south before snow levels fall but a
  quick transition to snow will be possible just prior to
  precipitation ending with accumulations generally under an inch.
  A renewed threat for snow will come Saturday mainly focusing
  snow shower activity along the ID Panhandle and East Slopes. At
  this time, snow amounts with this activity will be light with up
  to a few inches in the mountains and less than an inch in the
  valleys. This will be very light and fluffy snow if it falls.

* Temperatures: High temperatures will be in the teens to 20s
  north to 20s and 30s south. Overnight lows will be manageable
  Saturday morning with winds keeping temperatures up somewhat but
  should be very cold Sunday morning single digits to teens)

* Impacts: Moderate to heavy rain and high mountain snow in Idaho Friday
  night. Rapid transition to freezing temperatures Saturday
  morning could result in flash freeze of rain on most roadways.
  Strong winds Friday evening into Saturday could result in
  scattered power outages and difficult travel conditions for high
  profile vehicles. Light snow accumulations possible in the ID
  Panhandle Friday night into Saturday morning. Very cold
  temperatures during the weekend. /sb

Sunday night through Thursday...Sunday night looks on mark with
continued dry and benign conditions as jet stream and associated
stalled front remains to the south and north/northeast flow at low
levels keeps cold air remaining in place. I have lower confidence
in the Monday/Monday night part of the forecast with GFS runs
showing the front/deformation zone to the south moving back
northward as a warm front of sorts that would overrun the cold air
in place allowing for a prolonged period of mostly snow to fall
from it roughly south of a line drawn from the Tri-Cities to Coeur
d` Alene. The ECMWF shows this feature remaining much further
south and not influencing the forecast area and instead shows a
general Northwest to Southeast flow on the east side of the
offshore ridge remaining in place which could steer a minor
shortwave or two down and influence far Southeast Washington and
Northern Idaho with snow but not to the degree or intensity of the
GFS solution. I, and neighboring offices, feel the ECMWF solution
may be the better way to go as it brings back a negatively tilted
ridge that slowly amplifies with an axis close to the coast. The
ridge off the coast solution is what we have had in place for most
of this fall and having it move back in place seems very
reasonable to me. The end result of the ridge moving back in place
would be a gradual slow warming trend as the ridge amplifies and
the axis moves closer to Eastern Washington and Northern Idaho.
Late Thursday the same favored ECMWF depicts an occluded frontal
zone oriented north to south with a well maintained moisture feed
sweeping up in a southwest to northeast trajectory and overrunning
the slightly warmer yet still cold air in place over the area
which should bring moderate snow to many a lowland and mountain
location mostly independent of elevation. The expectation is the
ridge will likely slow this solution and delay front passage until
Friday or Saturday so have not increased pops for Thursday. Stay
tuned to see if this solution holds true. /Pelatti

&&

.AVIATION...
18Z TAFS: Swift westerly flow in the mid levels of the atmosphere
will promote a rain shadow with generally dry conditions this
evening at all TAF sites. Breezy winds this afternoon will
decrease as the boundary layer decouples tonight but swift
southwest flow will above the boundary layer will promote LLWS
over the eastern TAF sites late tonight and early Friday morning.
VFR conditions are expected at all TAF sites except KEAT. At KEAT
where a moist low level air mass remains in a protected valley IFR
conditions are likely to return after 06-08Z and persist until
early Friday afternoon. Winds will increase in a showery air mass
Friday afternoon with gusts to 40 KTS possible at the KPUW and
KGEG TAF sites after 20Z.

NOTE: The VIS sensor at EAT is out of service so amendments to
VIS are not scheduled. the offending sensor replacement is on
order and may be returned to service by Saturday. /MJF


&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        41  50  26  27  10  22 /  30  70  60  20   0   0
Coeur d`Alene  41  49  29  29  11  23 /  40  80 100  20  10   0
Pullman        43  53  31  32  11  25 /  60  90 100  50  10   0
Lewiston       46  57  37  38  21  28 /  50  70  90  60  20   0
Colville       40  47  22  23   4  21 /  40  70  50  10   0   0
Sandpoint      38  45  26  27   8  20 /  70  90 100  20  10   0
Kellogg        39  44  29  30  10  21 /  70  90 100  50  10   0
Moses Lake     41  55  27  29   9  24 /  10  30  20  10   0   0
Wenatchee      41  49  29  30  13  23 /  20  30  10  10   0   0
Omak           37  46  17  19   1  19 /  20  30  10  10   0   0

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Wind Advisory from 1 PM Friday to Midnight PST Friday Night for
     Idaho Palouse.

WA...Wind Advisory from 1 PM Friday to Midnight PST Friday Night for
     Lower Garfield and Asotin Counties-Spokane Area-Upper
     Columbia Basin-Washington Palouse.

&&

$$




000
FXUS66 KOTX 280018
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
418 PM PST THU NOV 27 2014

.SYNOPSIS...
A rainy and breezy weather pattern will envelope the region
tonight and Friday but snow levels will remain above pass levels
for motorists traveling on Friday. The arrival of a very cold and
windy arctic front Friday Night into Saturday will bring winter
driving conditions to the mountain passes and much cooler weather
for the weekend. Cold conditions with a few minor snow bearing
weather disturbances are expected as the new work week begins.

&&

.DISCUSSION...
Tonight and Friday...A somewhat complex flow regime is apparent on
satellite this afternoon. Two Pacific moisture feeds are
perceptible...one feeding into southwest Oregon with the northern
fringe of this feed seeping up into the southeastern
Washington/north Idaho zones and the second fetching into
Vancouver Isle. The southern fetch will provide a fuel source for
mainly spotty showers tonight and into Friday morning into the
Palouse area and the Shoshone County mountains. The northern feed
will slump southward and become better directed into the forecast
area tonight and sag further through the remainder of the forecast
area during the day Friday...driven through by an upper level
trough descending down the British Columbia coast and generating a
surface low under it`s dynamic foot over southern British
Columbia. This low is implied by the baroclinic leaf cloud shield
over central BC and Alberta.

Latest GFS and Nam and ECMWF models are in decent agreement in
evolving this flow regime. The BC surface low will move south and
enter the forecast area Friday morning...deepening as it
does...and move down the Washington/Idaho border. It will be
fueled by the northern deep moisture feed as it does. The presence
of this deepening surface low will help spread the precipitation
shield out into the basin...not just the mountains where the fast
westerly flow would imply a strong orographic component.

Thus the forecast for the next 24 hours will become increasingly
wet. All zones will be subject to light rain...with the best
chance for a significant period of rain on Friday over the
eastern and northern portions of the forecast area and over the
Cascades. Snow levels will remain between 5000 and 6000 feet until
the surface low passes to the south Friday night.

Winds will continue to be a dominant issue through Friday with
model soundings suggesting gust potential to 40 to 50 mph over the
exposed terrain of the eastern basin by Friday afternoon. A Wind
Advisory will be issued with the afternoon package for most of
the zones of the eastern basin. This breezy air mass will once
again promote mild temperatures for overnight lows tonight and
Friday high temps. /Fugazzi

Friday night through Sunday: This period will feature a big transition
from wet and mild weather toward cold and dry conditions. As this
transition occurs Friday night into Saturday, anticipate gusty
winds, periods of light to moderate precipitation (mainly in the
form of valley rain and high mountain snow), and concluding with
the potential for brief valley snow and potential for a few inches
within the eastern mountains.

* Synoptic Overview: Arctic air currently resides under the
  upper- level trof over Northern British Columbia. This low will
  pick up momentum during the next 24 hours then rapidly
  accelerate southward through the region Friday night into
  Saturday morning. The low will interact with a stalled frontal
  boundary draped along the International border promoting
  cyclogenesis (deepening surface low) and a strong surface low
  (990-994mb) deepens somewhere along the WA/ID border between
  I-90 and Canadian Border. Intense pressure gradients will setup
  on both sides of the low...first bringing a SW wind threat along
  its southern periphery Friday evening then along its northern
  periphery early Saturday morning into mid afternoon as the low
  sags south and dense arctic air mass floods in from Canada.

* Winds: Strong southwest winds are expected Friday evening and
  night across southeastern WA and into the ID Palouse as well as
  most mountain ridgetops associated with a strengthening low-
  level jet of 45-55 kts. High Res data from UW along with Bufkit
  data indicate the potential for sustained winds of 15-30 mph
  with gusts 35-55 mph for locations across the West Plains,
  Columbia Basin, Palouse, and foothills of the Blue Mtns.
  Mountain gusts from Mission Ridge to the Blue Mtns to the
  Central Panhandle Mtns will also be susceptible to gusts in
  excess of 50 mph. The strongest winds in these areas will be
  between Friday afternoon and Friday evening. Confidence high
  that the winds will exist roughly 2-4K feet above the surface
  but lower if these gusts will surface to valley floors. Data
  suggest a moderate threat and wind advisory has been issued.

* North winds will move into northern WA Friday evening and
  continue into Saturday. The strongest winds will be through the
  Okanogan Valley...spilling into the Waterville Plateau and
  western Basin. Winds of 15-30 mph with gusts to 45 mph are
  anticipated in these areas. With the air mass change so
  dramatic, I anticipate most north to south oriented valleys
  across Nrn WA will experience breezy conditions. Mountains,
  especially with a north aspect, will also feel gusty winds.

* Precipitation: Moderate to locally heavy precipitation will
  fall within the warm sector of the low bringing up to an inch of
  liquid to the mountains of Idaho and a general quarter to three
  quarters of an inch along the Cascade Crest and locations east
  of a line from Colville to Ritzville (outside the typical
  Cascade rain shadow) This will fall as rain below 6000 feet
  initially but snow levels will be crashing to valley floors with
  the arctic frontal passage Friday night. We don`t typically see
  much in the way of snow accumulations with these patterns as the
  deeper moisture gets shoved south before snow levels fall but a
  quick transition to snow will be possible just prior to
  precipitation ending with accumulations generally under an inch.
  A renewed threat for snow will come Saturday mainly focusing
  snow shower activity along the ID Panhandle and East Slopes. At
  this time, snow amounts with this activity will be light with up
  to a few inches in the mountains and less than an inch in the
  valleys. This will be very light and fluffy snow if it falls.

* Temperatures: High temperatures will be in the teens to 20s
  north to 20s and 30s south. Overnight lows will be manageable
  Saturday morning with winds keeping temperatures up somewhat but
  should be very cold Sunday morning single digits to teens)

* Impacts: Moderate to heavy rain and high mountain snow in Idaho Friday
  night. Rapid transition to freezing temperatures Saturday
  morning could result in flash freeze of rain on most roadways.
  Strong winds Friday evening into Saturday could result in
  scattered power outages and difficult travel conditions for high
  profile vehicles. Light snow accumulations possible in the ID
  Panhandle Friday night into Saturday morning. Very cold
  temperatures during the weekend. /sb

Sunday night through Thursday...Sunday night looks on mark with
continued dry and benign conditions as jet stream and associated
stalled front remains to the south and north/northeast flow at low
levels keeps cold air remaining in place. I have lower confidence
in the Monday/Monday night part of the forecast with GFS runs
showing the front/deformation zone to the south moving back
northward as a warm front of sorts that would overrun the cold air
in place allowing for a prolonged period of mostly snow to fall
from it roughly south of a line drawn from the Tri-Cities to Coeur
d` Alene. The ECMWF shows this feature remaining much further
south and not influencing the forecast area and instead shows a
general Northwest to Southeast flow on the east side of the
offshore ridge remaining in place which could steer a minor
shortwave or two down and influence far Southeast Washington and
Northern Idaho with snow but not to the degree or intensity of the
GFS solution. I, and neighboring offices, feel the ECMWF solution
may be the better way to go as it brings back a negatively tilted
ridge that slowly amplifies with an axis close to the coast. The
ridge off the coast solution is what we have had in place for most
of this fall and having it move back in place seems very
reasonable to me. The end result of the ridge moving back in place
would be a gradual slow warming trend as the ridge amplifies and
the axis moves closer to Eastern Washington and Northern Idaho.
Late Thursday the same favored ECMWF depicts an occluded frontal
zone oriented north to south with a well maintained moisture feed
sweeping up in a southwest to northeast trajectory and overrunning
the slightly warmer yet still cold air in place over the area
which should bring moderate snow to many a lowland and mountain
location mostly independent of elevation. The expectation is the
ridge will likely slow this solution and delay front passage until
Friday or Saturday so have not increased pops for Thursday. Stay
tuned to see if this solution holds true. /Pelatti

&&

.AVIATION...
18Z TAFS: Swift westerly flow in the mid levels of the atmosphere
will promote a rain shadow with generally dry conditions this
evening at all TAF sites. Breezy winds this afternoon will
decrease as the boundary layer decouples tonight but swift
southwest flow will above the boundary layer will promote LLWS
over the eastern TAF sites late tonight and early Friday morning.
VFR conditions are expected at all TAF sites except KEAT. At KEAT
where a moist low level air mass remains in a protected valley IFR
conditions are likely to return after 06-08Z and persist until
early Friday afternoon. Winds will increase in a showery air mass
Friday afternoon with gusts to 40 KTS possible at the KPUW and
KGEG TAF sites after 20Z.

NOTE: The VIS sensor at EAT is out of service so amendments to
VIS are not scheduled. the offending sensor replacement is on
order and may be returned to service by Saturday. /MJF


&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        41  50  26  27  10  22 /  30  70  60  20   0   0
Coeur d`Alene  41  49  29  29  11  23 /  40  80 100  20  10   0
Pullman        43  53  31  32  11  25 /  60  90 100  50  10   0
Lewiston       46  57  37  38  21  28 /  50  70  90  60  20   0
Colville       40  47  22  23   4  21 /  40  70  50  10   0   0
Sandpoint      38  45  26  27   8  20 /  70  90 100  20  10   0
Kellogg        39  44  29  30  10  21 /  70  90 100  50  10   0
Moses Lake     41  55  27  29   9  24 /  10  30  20  10   0   0
Wenatchee      41  49  29  30  13  23 /  20  30  10  10   0   0
Omak           37  46  17  19   1  19 /  20  30  10  10   0   0

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Wind Advisory from 1 PM Friday to Midnight PST Friday Night for
     Idaho Palouse.

WA...Wind Advisory from 1 PM Friday to Midnight PST Friday Night for
     Lower Garfield and Asotin Counties-Spokane Area-Upper
     Columbia Basin-Washington Palouse.

&&

$$




000
FXUS66 KOTX 280018
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
418 PM PST THU NOV 27 2014

.SYNOPSIS...
A rainy and breezy weather pattern will envelope the region
tonight and Friday but snow levels will remain above pass levels
for motorists traveling on Friday. The arrival of a very cold and
windy arctic front Friday Night into Saturday will bring winter
driving conditions to the mountain passes and much cooler weather
for the weekend. Cold conditions with a few minor snow bearing
weather disturbances are expected as the new work week begins.

&&

.DISCUSSION...
Tonight and Friday...A somewhat complex flow regime is apparent on
satellite this afternoon. Two Pacific moisture feeds are
perceptible...one feeding into southwest Oregon with the northern
fringe of this feed seeping up into the southeastern
Washington/north Idaho zones and the second fetching into
Vancouver Isle. The southern fetch will provide a fuel source for
mainly spotty showers tonight and into Friday morning into the
Palouse area and the Shoshone County mountains. The northern feed
will slump southward and become better directed into the forecast
area tonight and sag further through the remainder of the forecast
area during the day Friday...driven through by an upper level
trough descending down the British Columbia coast and generating a
surface low under it`s dynamic foot over southern British
Columbia. This low is implied by the baroclinic leaf cloud shield
over central BC and Alberta.

Latest GFS and Nam and ECMWF models are in decent agreement in
evolving this flow regime. The BC surface low will move south and
enter the forecast area Friday morning...deepening as it
does...and move down the Washington/Idaho border. It will be
fueled by the northern deep moisture feed as it does. The presence
of this deepening surface low will help spread the precipitation
shield out into the basin...not just the mountains where the fast
westerly flow would imply a strong orographic component.

Thus the forecast for the next 24 hours will become increasingly
wet. All zones will be subject to light rain...with the best
chance for a significant period of rain on Friday over the
eastern and northern portions of the forecast area and over the
Cascades. Snow levels will remain between 5000 and 6000 feet until
the surface low passes to the south Friday night.

Winds will continue to be a dominant issue through Friday with
model soundings suggesting gust potential to 40 to 50 mph over the
exposed terrain of the eastern basin by Friday afternoon. A Wind
Advisory will be issued with the afternoon package for most of
the zones of the eastern basin. This breezy air mass will once
again promote mild temperatures for overnight lows tonight and
Friday high temps. /Fugazzi

Friday night through Sunday: This period will feature a big transition
from wet and mild weather toward cold and dry conditions. As this
transition occurs Friday night into Saturday, anticipate gusty
winds, periods of light to moderate precipitation (mainly in the
form of valley rain and high mountain snow), and concluding with
the potential for brief valley snow and potential for a few inches
within the eastern mountains.

* Synoptic Overview: Arctic air currently resides under the
  upper- level trof over Northern British Columbia. This low will
  pick up momentum during the next 24 hours then rapidly
  accelerate southward through the region Friday night into
  Saturday morning. The low will interact with a stalled frontal
  boundary draped along the International border promoting
  cyclogenesis (deepening surface low) and a strong surface low
  (990-994mb) deepens somewhere along the WA/ID border between
  I-90 and Canadian Border. Intense pressure gradients will setup
  on both sides of the low...first bringing a SW wind threat along
  its southern periphery Friday evening then along its northern
  periphery early Saturday morning into mid afternoon as the low
  sags south and dense arctic air mass floods in from Canada.

* Winds: Strong southwest winds are expected Friday evening and
  night across southeastern WA and into the ID Palouse as well as
  most mountain ridgetops associated with a strengthening low-
  level jet of 45-55 kts. High Res data from UW along with Bufkit
  data indicate the potential for sustained winds of 15-30 mph
  with gusts 35-55 mph for locations across the West Plains,
  Columbia Basin, Palouse, and foothills of the Blue Mtns.
  Mountain gusts from Mission Ridge to the Blue Mtns to the
  Central Panhandle Mtns will also be susceptible to gusts in
  excess of 50 mph. The strongest winds in these areas will be
  between Friday afternoon and Friday evening. Confidence high
  that the winds will exist roughly 2-4K feet above the surface
  but lower if these gusts will surface to valley floors. Data
  suggest a moderate threat and wind advisory has been issued.

* North winds will move into northern WA Friday evening and
  continue into Saturday. The strongest winds will be through the
  Okanogan Valley...spilling into the Waterville Plateau and
  western Basin. Winds of 15-30 mph with gusts to 45 mph are
  anticipated in these areas. With the air mass change so
  dramatic, I anticipate most north to south oriented valleys
  across Nrn WA will experience breezy conditions. Mountains,
  especially with a north aspect, will also feel gusty winds.

* Precipitation: Moderate to locally heavy precipitation will
  fall within the warm sector of the low bringing up to an inch of
  liquid to the mountains of Idaho and a general quarter to three
  quarters of an inch along the Cascade Crest and locations east
  of a line from Colville to Ritzville (outside the typical
  Cascade rain shadow) This will fall as rain below 6000 feet
  initially but snow levels will be crashing to valley floors with
  the arctic frontal passage Friday night. We don`t typically see
  much in the way of snow accumulations with these patterns as the
  deeper moisture gets shoved south before snow levels fall but a
  quick transition to snow will be possible just prior to
  precipitation ending with accumulations generally under an inch.
  A renewed threat for snow will come Saturday mainly focusing
  snow shower activity along the ID Panhandle and East Slopes. At
  this time, snow amounts with this activity will be light with up
  to a few inches in the mountains and less than an inch in the
  valleys. This will be very light and fluffy snow if it falls.

* Temperatures: High temperatures will be in the teens to 20s
  north to 20s and 30s south. Overnight lows will be manageable
  Saturday morning with winds keeping temperatures up somewhat but
  should be very cold Sunday morning single digits to teens)

* Impacts: Moderate to heavy rain and high mountain snow in Idaho Friday
  night. Rapid transition to freezing temperatures Saturday
  morning could result in flash freeze of rain on most roadways.
  Strong winds Friday evening into Saturday could result in
  scattered power outages and difficult travel conditions for high
  profile vehicles. Light snow accumulations possible in the ID
  Panhandle Friday night into Saturday morning. Very cold
  temperatures during the weekend. /sb

Sunday night through Thursday...Sunday night looks on mark with
continued dry and benign conditions as jet stream and associated
stalled front remains to the south and north/northeast flow at low
levels keeps cold air remaining in place. I have lower confidence
in the Monday/Monday night part of the forecast with GFS runs
showing the front/deformation zone to the south moving back
northward as a warm front of sorts that would overrun the cold air
in place allowing for a prolonged period of mostly snow to fall
from it roughly south of a line drawn from the Tri-Cities to Coeur
d` Alene. The ECMWF shows this feature remaining much further
south and not influencing the forecast area and instead shows a
general Northwest to Southeast flow on the east side of the
offshore ridge remaining in place which could steer a minor
shortwave or two down and influence far Southeast Washington and
Northern Idaho with snow but not to the degree or intensity of the
GFS solution. I, and neighboring offices, feel the ECMWF solution
may be the better way to go as it brings back a negatively tilted
ridge that slowly amplifies with an axis close to the coast. The
ridge off the coast solution is what we have had in place for most
of this fall and having it move back in place seems very
reasonable to me. The end result of the ridge moving back in place
would be a gradual slow warming trend as the ridge amplifies and
the axis moves closer to Eastern Washington and Northern Idaho.
Late Thursday the same favored ECMWF depicts an occluded frontal
zone oriented north to south with a well maintained moisture feed
sweeping up in a southwest to northeast trajectory and overrunning
the slightly warmer yet still cold air in place over the area
which should bring moderate snow to many a lowland and mountain
location mostly independent of elevation. The expectation is the
ridge will likely slow this solution and delay front passage until
Friday or Saturday so have not increased pops for Thursday. Stay
tuned to see if this solution holds true. /Pelatti

&&

.AVIATION...
18Z TAFS: Swift westerly flow in the mid levels of the atmosphere
will promote a rain shadow with generally dry conditions this
evening at all TAF sites. Breezy winds this afternoon will
decrease as the boundary layer decouples tonight but swift
southwest flow will above the boundary layer will promote LLWS
over the eastern TAF sites late tonight and early Friday morning.
VFR conditions are expected at all TAF sites except KEAT. At KEAT
where a moist low level air mass remains in a protected valley IFR
conditions are likely to return after 06-08Z and persist until
early Friday afternoon. Winds will increase in a showery air mass
Friday afternoon with gusts to 40 KTS possible at the KPUW and
KGEG TAF sites after 20Z.

NOTE: The VIS sensor at EAT is out of service so amendments to
VIS are not scheduled. the offending sensor replacement is on
order and may be returned to service by Saturday. /MJF


&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        41  50  26  27  10  22 /  30  70  60  20   0   0
Coeur d`Alene  41  49  29  29  11  23 /  40  80 100  20  10   0
Pullman        43  53  31  32  11  25 /  60  90 100  50  10   0
Lewiston       46  57  37  38  21  28 /  50  70  90  60  20   0
Colville       40  47  22  23   4  21 /  40  70  50  10   0   0
Sandpoint      38  45  26  27   8  20 /  70  90 100  20  10   0
Kellogg        39  44  29  30  10  21 /  70  90 100  50  10   0
Moses Lake     41  55  27  29   9  24 /  10  30  20  10   0   0
Wenatchee      41  49  29  30  13  23 /  20  30  10  10   0   0
Omak           37  46  17  19   1  19 /  20  30  10  10   0   0

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Wind Advisory from 1 PM Friday to Midnight PST Friday Night for
     Idaho Palouse.

WA...Wind Advisory from 1 PM Friday to Midnight PST Friday Night for
     Lower Garfield and Asotin Counties-Spokane Area-Upper
     Columbia Basin-Washington Palouse.

&&

$$





000
FXUS66 KSEW 280008
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
408 PM PST THU NOV 27 2014

.SYNOPSIS...A COLD FRONT WILL MOVE SOUTH ACROSS WESTERN WA LATE
TONIGHT AND FRIDAY MORNING PRODUCING HEAVY RAIN OVER THE MOUNTAINS
AND OVER PARTS OF THE PUGET SOUND REGION. A CONVERGENCE ZONE WILL
CONTINUE OVER PUGET SOUND FRIDAY NIGHT...THEN ANOTHER COLD FRONT
WITH MODIFIED ARCTIC AIR WILL MOVE SOUTH THROUGH THE AREA LATE
FRIDAY NIGHT INTO SATURDAY MORNING. SOME SNOW OR RAIN AND SNOW MIXED
IS LIKELY TO OCCUR WITH THE CONVERGENCE ZONE AND ALONG THIS SECOND
FRONT. COOL NORTHWEST FLOW ALOFT WILL BRING MAINLY COOL AND DRY
WEATHER SUNDAY THROUGH EARLY NEXT WEEK.

&&

.SHORT TERM...VERY ACTIVE AND CHANGEABLE WEATHER IS EXPECTED OVER
THE AREA THROUGH SATURDAY.

THE WARM FRONT FROM A COUPLE OF DAYS AGO IS STILL UP OVER B.C. AND
POISED TO MOVE BACK S OVER W WA AS A FAIRLY STRONG COLD FRONT
TONIGHT. RECENT MODELS ARE IN FAIRLY GOOD AGREEMENT WITH THE
TIMING...BRINGING THE FRONT TO A N COAST-BLI LINE AT 09Z/1 AM...TO A
HQM-PAE LINE 15Z/7AM...AND TO APPROXIMATELY AN AST-CLS LINE AROUND
19Z/11 AM. RAIN WILL INCREASE TONIGHT AND BE HEAVY IN SOME LOWLAND
AREAS AS WELL AS OVER THE MOUNTAINS. THE AIR MASS WILL REMAIN MOIST
AND MILD WITH LOWLAND TEMPERATURES IN THE 50S.

THE MAIN SHORT TERM PROBLEM IS HEAVY RAIN OVER THE MOUNTAINS WHICH
STILL POSES A FLOODING THREAT TO SOME AREA RIVERS. SEE THE HYDROLOGY
SECTION BELOW FOR MORE DETAIL. THE HEAVY RAIN OVER THE MOUNTAINS
WILL SHUT OFF BEHIND THE COLD FRONT. SOME EARLIER MODELS SHOWED SOME
RATHER HEAVY RAIN OVER OVER THE GREATER PUGET SOUND REGION WITH THE
FRONT...BUT THE NEWEST 12Z RUNS HAVE TAKEN A STEP BACK. THE
HIRES-ARW MODEL REMAINS THE HEAVIEST PRECIP PRODUCER WITH AROUND AN
INCH WITH THE FRONT. THE 12Z NAM12 AND HIRES-NMM MODELS ARE MUCH
LIGHTER. TEMPERATURES WILL REMAIN WARM ENOUGH TO KEEP THE PRECIP ALL
RAIN. TEMPERATURES WILL FALL INTO THE 30S TO LOWER 40S BY LATE
FRIDAY AFTERNOON.

BEHIND THE COLD FRONT A CONVERGENCE ZONE WILL FORM OVER CENTRAL
PUGET SOUND LATE FRIDAY AFTERNOON AND CONTINUE INTO FRIDAY NIGHT.
TEMPERATURES WILL FALL INTO THE LOWER TO MID 30S BY MID EVENING WITH
SNOW LEVELS FALLING BELOW 1000 FEET...SO THE CONVERGENCE ZONE MAY
PRODUCE SOME SNOW FROM NORTH SEATTLE UP THROUGH ARLINGTON. SNOW
ACCUMULATIONS WILL PROBABLY BE AN INCH OR LESS BUT THERE COULD BE
LOCAL HIGHER ACCUMULATIONS DEPENDING UPON LOCATION AND DURATION OF
THE CONVERGENCE ZONE.

MODIFIED ARCTIC AIR WILL BEGIN SPILLING OUT OF THE FRASER VALLEY
FRIDAY EVENING. IT WILL BECOME VERY WINDY OVER PARTS OF THE N
INTERIOR FROM WHATCOM COUNTY ACROSS THE SAN JUAN ISLANDS. BEST GUESS
IS THAT WINDS WILL END UP IN THE WIND ADVISORY RANGE...BUT SOME
LOCAL HIGH WINDS ARE NOT OUT OF THE QUESTION. A HIGH WIND WATCH HAS
BEEN ISSUED FOR THIS. WITH AIR TEMPERATURES IN THE 20S...WIND CHILLS
WILL END UP IN THE TEENS AND SOME FREEZING SPRAY IS NOT OUT OF THE
QUESTION.

THE MODIFIED ARCTIC AIR WILL SPILL S ACROSS PUGET SOUND AS ANOTHER
COLD FRONT LATE FRIDAY NIGHT AND SATURDAY MORNING...AND SPILL WEST
THROUGH THE STRAIT OF JUAN DE FUCA. MORE WIDESPREAD LIGHT SNOW IS
LIKELY ACROSS THE GREATER PUGET SOUND REGION...AND OVER THE SW
INTERIOR AND OUT TOWARDS THE COAST. AGAIN THE MOST LIKELY OUTCOME IS
AN INCH OR LESS OF SNOW WITH LOCAL AMOUNTS OF A COUPLE OF INCHES.
HOWEVER UNCERTAINTY IS HIGH AND HEAVIER AMOUNTS AROUND 3 INCHES OR
SO ARE POSSIBLE.

OVER THE EASTERN STRAIT OF JUAN DE FUCA AREAS...NE OUTFLOW WINDS
WILL FLOW OVER THE N PART OF THE OLYMPICS...BRINGING UPSLOPE SNOW TO
AREAS ALONG THE STRAIT. THE MOST LIKELY SCENARIO IS FOR AN INCH OR
LESS NEAR THE IMMEDIATE COASTLINE AND POSSIBLY AN INCH OR TWO MORE
OVER THE HIGHER HILLS AWAY FROM THE COASTLINE. ONCE AGAIN
UNCERTAINTY IS HIGH AND AMOUNTS WILL DEPEND UPON HOW MOIST THE AIR
IS AND HOW MUCH UPSLOPE FLOW IS GENERATED.

COLD DRY MODIFIED ARCTIC AIR WILL PRETTY MUCH COVER W WA BY SATURDAY
EVENING WITH CLEARING SKIES. TEMPERATURES WILL DROP INTO THE UPPER
TEENS TO MID 20S BY SUNDAY MORNING. KAM

.LONG TERM...ONLY MINOR CHANGES WERE MADE TO THE LONG TERM
FORECAST...MONDAY THROUGH THURSDAY. THE SET-UP HAS A NORTHERN STREAM
RIDGE OFFSHORE OVER THE NE PACIFIC...WITH COOL NW FLOW ALOFT OVER W
WA. ALSO IN THE PICTURE IS A SOUTHERN STREAM CLOSED LOW W OF THE CA
COAST. WASHINGTON APPEARS TO BE CONTESTED TERRITORY BETWEEN THE
NORTHERN AND SOUTHERN STREAMS WHICH MEANS MODEL BATTLES TO DETERMINE
WHICH STREAM WILL WIN OUT. THE ECMWF HAS BEEN MORE OR LESS
CONSISTENTLY KEEPING THE AREA UNDER THE COOLER DRIER AND SUNNIER N
STREAM THROUGH MID NEXT WEEK. THE GFS HAS BEEN WOBBLING BETWEEN THE
ECMWF SOLUTION AND A WETTER SOUTHERN STREAM SOLUTION. FORECASTS
CONTINUE TO FOLLOW THE ECMWF...BUT CONFIDENCE IS ONLY MODERATE GIVEN
THE MODEL CONFLICTS AND THE OVERALL DIFFICULTY IN RESOLVING A
PATTERN LIKE THIS. MODELS DO AGREE THAT A SHORTWAVE TROUGH WILL MOVE
SE ACROSS THE AREA ON MONDAY. THIS LOOKS DRY AT THIS POINT BUT MORE
CLOUDS AND POSSIBLY SOME LIGHT PRECIP MAY NEED TO BE ADDED TO THE
FORECAST IF MODEL SOLUTIONS CHANGE. KAM

&&

.HYDROLOGY...THERE HAS BEEN A DISTINCT LULL IN RAINFALL TODAY WITH
WASHINGTON PRETTY CLEARLY BETWEEN SYSTEMS. RAINFALL AMOUNTS IN THE
MOUNTAINS HAVE BEEN LIGHTER THAN FORECAST. RIVERS HAVE BEEN STEADY
OR HAVE RISEN SLOWLY IN RESPONSE TO EARLIER RAIN.

THE FRONT THAT IS CURRENTLY IN SOUTHERN BRITISH COLUMBIA IS FORECAST
TO MOVE SOUTH TONIGHT AND TO CONTINUE SOUTH OUT OF THE STATE BY
FRIDAY EVENING. IT WILL BRING ANOTHER 2-4 INCHES OF RAIN TO THE
MOUNTAINS. CURRENT QPF REFLECTS A BLEND OF MESOSCALE MODELS. HEAVY
RAIN WILL REDEVELOP THIS EVENING AND SPREAD SOUTH OVERNIGHT. THE
RAINIEST PERIOD IS 12Z-18Z FRIDAY WHEN 1-1.5 INCHES OF RAIN IS
FORECAST OVER THE CASCADES OF SNOHOMISH AND KING COUNTIES...WITH UP
TO AN INCH OVER THE LOWLANDS OF THOSE COUNTIES. RAIN SHOULD TAPER IN
THE AFTERNOON AS THE AIR MASS COOLS AND DRIES FROM THE NORTH.

THE US ARMY CORPS OF ENGINEERS HAS TAKEN CONTROL OF DAM OPERATION ON
THE SKAGIT AND BAKER RIVERS. AS A RESULT THE SKAGIT RIVER SHOULD
HAVE ONLY MINOR FLOODING ON BOTH THE CONCRETE AND MOUNT VERNON
REACHES. A FLOOD WARNING HAS BEEN POSTED FOR THE SKAGIT RIVER.

THE NOOKSACK RIVER IS ALSO FORECAST TO REACH FLOOD STAGE AT NORTH
CEDARVILLE AND FERNDALE. HOWEVER THE LACK OF HEAVY RAIN TODAY WILL
DELAY ANY FLOODING UNTIL LATE TONIGHT OR FRIDAY.

HEAVY RAIN WILL REACH THE BASINS OF RIVERS FLOWING OFF THE CASCADES
OF SNOHOMISH AND KING COUNTIES LATE TONIGHT AND CONTINUE INTO THE
DAY FRIDAY. A SHEAF OF RIVERS FROM THE STILLAGUAMISH SOUTH TO THE
PUYALLUP NEAR ORTING...INCLUDING THE SKYKOMISH...SNOQUALMIE...
TOLT...AND SNOHOMISH...COULD ALL REACH FLOOD STAGE FROM THIS SHORT
BUT INTENSE BURST OF HEAVY RAIN. ANY FLOODING ON THESE RIVERS IS
EXPECTED TO BE MINOR.

THE SOUTHERN TIER OF RIVERS APPEAR TO BE AT LESS RISK OF FLOODING.
IN THE MODELS THE FRONT SEEMS A BIT SPENT AS IT MOVES INTO THE
SOUTHERN COUNTIES...PIERCE AND LEWIS...AND RAINFALL MAY NOT BE AS
HEAVY AS IN THE NORTHERN COUNTIES. A FLOOD WATCH REMAINS IN EFFECT
FOR ALL COUNTIES FROM WHATCOM TO LEWIS...AS WELL AS MASON COUNTY.

SPEAKING OF MASON COUNTY...THE SKOKOMISH RIVER IS ABOVE FLOOD STAGE
AND WILL LIKELY REMAIN NEAR OR ABOVE FLOOD STAGE THROUGH FRIDAY
NIGHT. THE FLOOD WARNING THERE REMAINS IN EFFECT. BURKE

&&

.AVIATION...THE FLOW ALOFT IS W/SW. THE AIR MASS IS MOIST AND
UNSTABLE. RAIN SHOWERS WILL CONTINUE TONIGHT...WITH MVFR AND VFR
CIGS AT MOST OF THE TERMINALS. A STRONG COLD FRONT WILL MOVE SOUTH
THROUGH THE AREA BETWEEN 10Z AND 17Z EARLY FRIDAY MORNING...AND
WINDS WILL SHARPLY SWITCH FROM S TO NW AT THE TERMINALS. MODERATE
RAIN AND DECREASED VISIBILITIES ARE POSSIBLE WITH CONVERGENCE FROM
THE FRONT. AFTER THE FRONTAL SYSTEM MOVES THROUGH...A PUGET SOUND
CONVERGENCE ZONE MAY FORM OVER PAE FRIDAY NIGHT INTO SATURDAY...AND
TEMPERATURES WILL BE COLD ENOUGH FOR PRECIPITATION TO FALL AS SNOW.
KCLM MAY ALSO BE AFFECTED BY UPSLOPE FLOW OVER THE OLYMPICS.

KSEA...EXPECT RAIN SHOWERS THROUGH TONIGHT...WITH POSSIBLE MODERATE
RAIN EARLY FRIDAY JUST BEFORE THE FRONTAL PASSAGE. GUSTY SOUTH WINDS
WILL CHANGE TO N WITH THE PASSAGE OF THE COLD FRONT AROUND 15Z.
THERE MAY BE A BRIEF PERIOD FOR AN HOUR OR SO WHERE THE WINDS AT BFI
ARE FROM THE N AND WINDS AT SEATAC ARE FROM THE S JUST BEFORE
FRONTAL PASSAGE. THIS MAY ALSO OCCUR AGAIN WHEN SURFACE WINDS SWITCH
TO SOUTH IN THE EARLY AFTERNOON FRIDAY. LATE FRIDAY NIGHT INTO
SATURDAY...THERE IS A CHANCE FOR SNOW AT SEA-TAC WITH MODIFIED
ARCTIC AIR IN THE AREA. AT THIS POINT WE ARE LOOKING AT
ACCUMULATIONS OF AN INCH OR LESS. JSMITH

&&

.MARINE...SMALL CRAFT ADVISORIES ARE IN EFFECT FOR ALL ZONES...WITH
HIGHER PRESSURE IN THE SOUTH AND LOWER PRESSURE IN THE NORTH
PRODUCING HIGH END SMALL CRAFT ADVISORY LEVEL WINDS. PRESSURE
GRADIENTS WILL REMAIN TIGHT TONIGHT THROUGH FRI MORNING AS A WELL
DEVELOPED COLD FRONT SHIFTS SOUTH INTO WESTERN WA. WINDS WILL SWITCH
FROM THE SW TO THE N OR NW AS THE FRONT MOVES THROUGH.

STRONG HIGH PRES OVER INTERIOR B.C. WILL BRING N/NE FRASER RIVER
OUTFLOW WINDS LATE FRI NIGHT INTO SAT AND A GALE WATCH HAS BEEN
ISSUED FOR THE NORTHERN INLAND WATERS AND EAST ENTRANCE TO THE
STRAIT. OFFSHORE FLOW WILL PREVAIL EARLY NEXT WEEK WITH HIGH PRES
EAST OF THE CASCADES. JSMITH

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...FLOOD WATCHES AND WARNINGS IN EFFECT FOR PORTIONS OF
      WESTERN WASHINGTON.
     HIGH WIND WATCH NORTH INTERIOR FRIDAY NIGHT AND SATURDAY.
PZ...GALE WATCH NORTHERN INLAND WATERS AND EAST ENTRANCE STRAIT OF
      JUAN DE FUCA FOR FRIDAY NIGHT AND SATURDAY.
     SMALL CRAFT ADVISORY ALL WATERS.
     SMALL CRAFT ADVISORY GRAYS HARBOR BAR FOR ROUGH 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 280008
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
408 PM PST THU NOV 27 2014

.SYNOPSIS...A COLD FRONT WILL MOVE SOUTH ACROSS WESTERN WA LATE
TONIGHT AND FRIDAY MORNING PRODUCING HEAVY RAIN OVER THE MOUNTAINS
AND OVER PARTS OF THE PUGET SOUND REGION. A CONVERGENCE ZONE WILL
CONTINUE OVER PUGET SOUND FRIDAY NIGHT...THEN ANOTHER COLD FRONT
WITH MODIFIED ARCTIC AIR WILL MOVE SOUTH THROUGH THE AREA LATE
FRIDAY NIGHT INTO SATURDAY MORNING. SOME SNOW OR RAIN AND SNOW MIXED
IS LIKELY TO OCCUR WITH THE CONVERGENCE ZONE AND ALONG THIS SECOND
FRONT. COOL NORTHWEST FLOW ALOFT WILL BRING MAINLY COOL AND DRY
WEATHER SUNDAY THROUGH EARLY NEXT WEEK.

&&

.SHORT TERM...VERY ACTIVE AND CHANGEABLE WEATHER IS EXPECTED OVER
THE AREA THROUGH SATURDAY.

THE WARM FRONT FROM A COUPLE OF DAYS AGO IS STILL UP OVER B.C. AND
POISED TO MOVE BACK S OVER W WA AS A FAIRLY STRONG COLD FRONT
TONIGHT. RECENT MODELS ARE IN FAIRLY GOOD AGREEMENT WITH THE
TIMING...BRINGING THE FRONT TO A N COAST-BLI LINE AT 09Z/1 AM...TO A
HQM-PAE LINE 15Z/7AM...AND TO APPROXIMATELY AN AST-CLS LINE AROUND
19Z/11 AM. RAIN WILL INCREASE TONIGHT AND BE HEAVY IN SOME LOWLAND
AREAS AS WELL AS OVER THE MOUNTAINS. THE AIR MASS WILL REMAIN MOIST
AND MILD WITH LOWLAND TEMPERATURES IN THE 50S.

THE MAIN SHORT TERM PROBLEM IS HEAVY RAIN OVER THE MOUNTAINS WHICH
STILL POSES A FLOODING THREAT TO SOME AREA RIVERS. SEE THE HYDROLOGY
SECTION BELOW FOR MORE DETAIL. THE HEAVY RAIN OVER THE MOUNTAINS
WILL SHUT OFF BEHIND THE COLD FRONT. SOME EARLIER MODELS SHOWED SOME
RATHER HEAVY RAIN OVER OVER THE GREATER PUGET SOUND REGION WITH THE
FRONT...BUT THE NEWEST 12Z RUNS HAVE TAKEN A STEP BACK. THE
HIRES-ARW MODEL REMAINS THE HEAVIEST PRECIP PRODUCER WITH AROUND AN
INCH WITH THE FRONT. THE 12Z NAM12 AND HIRES-NMM MODELS ARE MUCH
LIGHTER. TEMPERATURES WILL REMAIN WARM ENOUGH TO KEEP THE PRECIP ALL
RAIN. TEMPERATURES WILL FALL INTO THE 30S TO LOWER 40S BY LATE
FRIDAY AFTERNOON.

BEHIND THE COLD FRONT A CONVERGENCE ZONE WILL FORM OVER CENTRAL
PUGET SOUND LATE FRIDAY AFTERNOON AND CONTINUE INTO FRIDAY NIGHT.
TEMPERATURES WILL FALL INTO THE LOWER TO MID 30S BY MID EVENING WITH
SNOW LEVELS FALLING BELOW 1000 FEET...SO THE CONVERGENCE ZONE MAY
PRODUCE SOME SNOW FROM NORTH SEATTLE UP THROUGH ARLINGTON. SNOW
ACCUMULATIONS WILL PROBABLY BE AN INCH OR LESS BUT THERE COULD BE
LOCAL HIGHER ACCUMULATIONS DEPENDING UPON LOCATION AND DURATION OF
THE CONVERGENCE ZONE.

MODIFIED ARCTIC AIR WILL BEGIN SPILLING OUT OF THE FRASER VALLEY
FRIDAY EVENING. IT WILL BECOME VERY WINDY OVER PARTS OF THE N
INTERIOR FROM WHATCOM COUNTY ACROSS THE SAN JUAN ISLANDS. BEST GUESS
IS THAT WINDS WILL END UP IN THE WIND ADVISORY RANGE...BUT SOME
LOCAL HIGH WINDS ARE NOT OUT OF THE QUESTION. A HIGH WIND WATCH HAS
BEEN ISSUED FOR THIS. WITH AIR TEMPERATURES IN THE 20S...WIND CHILLS
WILL END UP IN THE TEENS AND SOME FREEZING SPRAY IS NOT OUT OF THE
QUESTION.

THE MODIFIED ARCTIC AIR WILL SPILL S ACROSS PUGET SOUND AS ANOTHER
COLD FRONT LATE FRIDAY NIGHT AND SATURDAY MORNING...AND SPILL WEST
THROUGH THE STRAIT OF JUAN DE FUCA. MORE WIDESPREAD LIGHT SNOW IS
LIKELY ACROSS THE GREATER PUGET SOUND REGION...AND OVER THE SW
INTERIOR AND OUT TOWARDS THE COAST. AGAIN THE MOST LIKELY OUTCOME IS
AN INCH OR LESS OF SNOW WITH LOCAL AMOUNTS OF A COUPLE OF INCHES.
HOWEVER UNCERTAINTY IS HIGH AND HEAVIER AMOUNTS AROUND 3 INCHES OR
SO ARE POSSIBLE.

OVER THE EASTERN STRAIT OF JUAN DE FUCA AREAS...NE OUTFLOW WINDS
WILL FLOW OVER THE N PART OF THE OLYMPICS...BRINGING UPSLOPE SNOW TO
AREAS ALONG THE STRAIT. THE MOST LIKELY SCENARIO IS FOR AN INCH OR
LESS NEAR THE IMMEDIATE COASTLINE AND POSSIBLY AN INCH OR TWO MORE
OVER THE HIGHER HILLS AWAY FROM THE COASTLINE. ONCE AGAIN
UNCERTAINTY IS HIGH AND AMOUNTS WILL DEPEND UPON HOW MOIST THE AIR
IS AND HOW MUCH UPSLOPE FLOW IS GENERATED.

COLD DRY MODIFIED ARCTIC AIR WILL PRETTY MUCH COVER W WA BY SATURDAY
EVENING WITH CLEARING SKIES. TEMPERATURES WILL DROP INTO THE UPPER
TEENS TO MID 20S BY SUNDAY MORNING. KAM

.LONG TERM...ONLY MINOR CHANGES WERE MADE TO THE LONG TERM
FORECAST...MONDAY THROUGH THURSDAY. THE SET-UP HAS A NORTHERN STREAM
RIDGE OFFSHORE OVER THE NE PACIFIC...WITH COOL NW FLOW ALOFT OVER W
WA. ALSO IN THE PICTURE IS A SOUTHERN STREAM CLOSED LOW W OF THE CA
COAST. WASHINGTON APPEARS TO BE CONTESTED TERRITORY BETWEEN THE
NORTHERN AND SOUTHERN STREAMS WHICH MEANS MODEL BATTLES TO DETERMINE
WHICH STREAM WILL WIN OUT. THE ECMWF HAS BEEN MORE OR LESS
CONSISTENTLY KEEPING THE AREA UNDER THE COOLER DRIER AND SUNNIER N
STREAM THROUGH MID NEXT WEEK. THE GFS HAS BEEN WOBBLING BETWEEN THE
ECMWF SOLUTION AND A WETTER SOUTHERN STREAM SOLUTION. FORECASTS
CONTINUE TO FOLLOW THE ECMWF...BUT CONFIDENCE IS ONLY MODERATE GIVEN
THE MODEL CONFLICTS AND THE OVERALL DIFFICULTY IN RESOLVING A
PATTERN LIKE THIS. MODELS DO AGREE THAT A SHORTWAVE TROUGH WILL MOVE
SE ACROSS THE AREA ON MONDAY. THIS LOOKS DRY AT THIS POINT BUT MORE
CLOUDS AND POSSIBLY SOME LIGHT PRECIP MAY NEED TO BE ADDED TO THE
FORECAST IF MODEL SOLUTIONS CHANGE. KAM

&&

.HYDROLOGY...THERE HAS BEEN A DISTINCT LULL IN RAINFALL TODAY WITH
WASHINGTON PRETTY CLEARLY BETWEEN SYSTEMS. RAINFALL AMOUNTS IN THE
MOUNTAINS HAVE BEEN LIGHTER THAN FORECAST. RIVERS HAVE BEEN STEADY
OR HAVE RISEN SLOWLY IN RESPONSE TO EARLIER RAIN.

THE FRONT THAT IS CURRENTLY IN SOUTHERN BRITISH COLUMBIA IS FORECAST
TO MOVE SOUTH TONIGHT AND TO CONTINUE SOUTH OUT OF THE STATE BY
FRIDAY EVENING. IT WILL BRING ANOTHER 2-4 INCHES OF RAIN TO THE
MOUNTAINS. CURRENT QPF REFLECTS A BLEND OF MESOSCALE MODELS. HEAVY
RAIN WILL REDEVELOP THIS EVENING AND SPREAD SOUTH OVERNIGHT. THE
RAINIEST PERIOD IS 12Z-18Z FRIDAY WHEN 1-1.5 INCHES OF RAIN IS
FORECAST OVER THE CASCADES OF SNOHOMISH AND KING COUNTIES...WITH UP
TO AN INCH OVER THE LOWLANDS OF THOSE COUNTIES. RAIN SHOULD TAPER IN
THE AFTERNOON AS THE AIR MASS COOLS AND DRIES FROM THE NORTH.

THE US ARMY CORPS OF ENGINEERS HAS TAKEN CONTROL OF DAM OPERATION ON
THE SKAGIT AND BAKER RIVERS. AS A RESULT THE SKAGIT RIVER SHOULD
HAVE ONLY MINOR FLOODING ON BOTH THE CONCRETE AND MOUNT VERNON
REACHES. A FLOOD WARNING HAS BEEN POSTED FOR THE SKAGIT RIVER.

THE NOOKSACK RIVER IS ALSO FORECAST TO REACH FLOOD STAGE AT NORTH
CEDARVILLE AND FERNDALE. HOWEVER THE LACK OF HEAVY RAIN TODAY WILL
DELAY ANY FLOODING UNTIL LATE TONIGHT OR FRIDAY.

HEAVY RAIN WILL REACH THE BASINS OF RIVERS FLOWING OFF THE CASCADES
OF SNOHOMISH AND KING COUNTIES LATE TONIGHT AND CONTINUE INTO THE
DAY FRIDAY. A SHEAF OF RIVERS FROM THE STILLAGUAMISH SOUTH TO THE
PUYALLUP NEAR ORTING...INCLUDING THE SKYKOMISH...SNOQUALMIE...
TOLT...AND SNOHOMISH...COULD ALL REACH FLOOD STAGE FROM THIS SHORT
BUT INTENSE BURST OF HEAVY RAIN. ANY FLOODING ON THESE RIVERS IS
EXPECTED TO BE MINOR.

THE SOUTHERN TIER OF RIVERS APPEAR TO BE AT LESS RISK OF FLOODING.
IN THE MODELS THE FRONT SEEMS A BIT SPENT AS IT MOVES INTO THE
SOUTHERN COUNTIES...PIERCE AND LEWIS...AND RAINFALL MAY NOT BE AS
HEAVY AS IN THE NORTHERN COUNTIES. A FLOOD WATCH REMAINS IN EFFECT
FOR ALL COUNTIES FROM WHATCOM TO LEWIS...AS WELL AS MASON COUNTY.

SPEAKING OF MASON COUNTY...THE SKOKOMISH RIVER IS ABOVE FLOOD STAGE
AND WILL LIKELY REMAIN NEAR OR ABOVE FLOOD STAGE THROUGH FRIDAY
NIGHT. THE FLOOD WARNING THERE REMAINS IN EFFECT. BURKE

&&

.AVIATION...THE FLOW ALOFT IS W/SW. THE AIR MASS IS MOIST AND
UNSTABLE. RAIN SHOWERS WILL CONTINUE TONIGHT...WITH MVFR AND VFR
CIGS AT MOST OF THE TERMINALS. A STRONG COLD FRONT WILL MOVE SOUTH
THROUGH THE AREA BETWEEN 10Z AND 17Z EARLY FRIDAY MORNING...AND
WINDS WILL SHARPLY SWITCH FROM S TO NW AT THE TERMINALS. MODERATE
RAIN AND DECREASED VISIBILITIES ARE POSSIBLE WITH CONVERGENCE FROM
THE FRONT. AFTER THE FRONTAL SYSTEM MOVES THROUGH...A PUGET SOUND
CONVERGENCE ZONE MAY FORM OVER PAE FRIDAY NIGHT INTO SATURDAY...AND
TEMPERATURES WILL BE COLD ENOUGH FOR PRECIPITATION TO FALL AS SNOW.
KCLM MAY ALSO BE AFFECTED BY UPSLOPE FLOW OVER THE OLYMPICS.

KSEA...EXPECT RAIN SHOWERS THROUGH TONIGHT...WITH POSSIBLE MODERATE
RAIN EARLY FRIDAY JUST BEFORE THE FRONTAL PASSAGE. GUSTY SOUTH WINDS
WILL CHANGE TO N WITH THE PASSAGE OF THE COLD FRONT AROUND 15Z.
THERE MAY BE A BRIEF PERIOD FOR AN HOUR OR SO WHERE THE WINDS AT BFI
ARE FROM THE N AND WINDS AT SEATAC ARE FROM THE S JUST BEFORE
FRONTAL PASSAGE. THIS MAY ALSO OCCUR AGAIN WHEN SURFACE WINDS SWITCH
TO SOUTH IN THE EARLY AFTERNOON FRIDAY. LATE FRIDAY NIGHT INTO
SATURDAY...THERE IS A CHANCE FOR SNOW AT SEA-TAC WITH MODIFIED
ARCTIC AIR IN THE AREA. AT THIS POINT WE ARE LOOKING AT
ACCUMULATIONS OF AN INCH OR LESS. JSMITH

&&

.MARINE...SMALL CRAFT ADVISORIES ARE IN EFFECT FOR ALL ZONES...WITH
HIGHER PRESSURE IN THE SOUTH AND LOWER PRESSURE IN THE NORTH
PRODUCING HIGH END SMALL CRAFT ADVISORY LEVEL WINDS. PRESSURE
GRADIENTS WILL REMAIN TIGHT TONIGHT THROUGH FRI MORNING AS A WELL
DEVELOPED COLD FRONT SHIFTS SOUTH INTO WESTERN WA. WINDS WILL SWITCH
FROM THE SW TO THE N OR NW AS THE FRONT MOVES THROUGH.

STRONG HIGH PRES OVER INTERIOR B.C. WILL BRING N/NE FRASER RIVER
OUTFLOW WINDS LATE FRI NIGHT INTO SAT AND A GALE WATCH HAS BEEN
ISSUED FOR THE NORTHERN INLAND WATERS AND EAST ENTRANCE TO THE
STRAIT. OFFSHORE FLOW WILL PREVAIL EARLY NEXT WEEK WITH HIGH PRES
EAST OF THE CASCADES. JSMITH

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...FLOOD WATCHES AND WARNINGS IN EFFECT FOR PORTIONS OF
      WESTERN WASHINGTON.
     HIGH WIND WATCH NORTH INTERIOR FRIDAY NIGHT AND SATURDAY.
PZ...GALE WATCH NORTHERN INLAND WATERS AND EAST ENTRANCE STRAIT OF
      JUAN DE FUCA FOR FRIDAY NIGHT AND SATURDAY.
     SMALL CRAFT ADVISORY ALL WATERS.
     SMALL CRAFT ADVISORY GRAYS HARBOR BAR FOR ROUGH 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 280008
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
408 PM PST THU NOV 27 2014

.SYNOPSIS...A COLD FRONT WILL MOVE SOUTH ACROSS WESTERN WA LATE
TONIGHT AND FRIDAY MORNING PRODUCING HEAVY RAIN OVER THE MOUNTAINS
AND OVER PARTS OF THE PUGET SOUND REGION. A CONVERGENCE ZONE WILL
CONTINUE OVER PUGET SOUND FRIDAY NIGHT...THEN ANOTHER COLD FRONT
WITH MODIFIED ARCTIC AIR WILL MOVE SOUTH THROUGH THE AREA LATE
FRIDAY NIGHT INTO SATURDAY MORNING. SOME SNOW OR RAIN AND SNOW MIXED
IS LIKELY TO OCCUR WITH THE CONVERGENCE ZONE AND ALONG THIS SECOND
FRONT. COOL NORTHWEST FLOW ALOFT WILL BRING MAINLY COOL AND DRY
WEATHER SUNDAY THROUGH EARLY NEXT WEEK.

&&

.SHORT TERM...VERY ACTIVE AND CHANGEABLE WEATHER IS EXPECTED OVER
THE AREA THROUGH SATURDAY.

THE WARM FRONT FROM A COUPLE OF DAYS AGO IS STILL UP OVER B.C. AND
POISED TO MOVE BACK S OVER W WA AS A FAIRLY STRONG COLD FRONT
TONIGHT. RECENT MODELS ARE IN FAIRLY GOOD AGREEMENT WITH THE
TIMING...BRINGING THE FRONT TO A N COAST-BLI LINE AT 09Z/1 AM...TO A
HQM-PAE LINE 15Z/7AM...AND TO APPROXIMATELY AN AST-CLS LINE AROUND
19Z/11 AM. RAIN WILL INCREASE TONIGHT AND BE HEAVY IN SOME LOWLAND
AREAS AS WELL AS OVER THE MOUNTAINS. THE AIR MASS WILL REMAIN MOIST
AND MILD WITH LOWLAND TEMPERATURES IN THE 50S.

THE MAIN SHORT TERM PROBLEM IS HEAVY RAIN OVER THE MOUNTAINS WHICH
STILL POSES A FLOODING THREAT TO SOME AREA RIVERS. SEE THE HYDROLOGY
SECTION BELOW FOR MORE DETAIL. THE HEAVY RAIN OVER THE MOUNTAINS
WILL SHUT OFF BEHIND THE COLD FRONT. SOME EARLIER MODELS SHOWED SOME
RATHER HEAVY RAIN OVER OVER THE GREATER PUGET SOUND REGION WITH THE
FRONT...BUT THE NEWEST 12Z RUNS HAVE TAKEN A STEP BACK. THE
HIRES-ARW MODEL REMAINS THE HEAVIEST PRECIP PRODUCER WITH AROUND AN
INCH WITH THE FRONT. THE 12Z NAM12 AND HIRES-NMM MODELS ARE MUCH
LIGHTER. TEMPERATURES WILL REMAIN WARM ENOUGH TO KEEP THE PRECIP ALL
RAIN. TEMPERATURES WILL FALL INTO THE 30S TO LOWER 40S BY LATE
FRIDAY AFTERNOON.

BEHIND THE COLD FRONT A CONVERGENCE ZONE WILL FORM OVER CENTRAL
PUGET SOUND LATE FRIDAY AFTERNOON AND CONTINUE INTO FRIDAY NIGHT.
TEMPERATURES WILL FALL INTO THE LOWER TO MID 30S BY MID EVENING WITH
SNOW LEVELS FALLING BELOW 1000 FEET...SO THE CONVERGENCE ZONE MAY
PRODUCE SOME SNOW FROM NORTH SEATTLE UP THROUGH ARLINGTON. SNOW
ACCUMULATIONS WILL PROBABLY BE AN INCH OR LESS BUT THERE COULD BE
LOCAL HIGHER ACCUMULATIONS DEPENDING UPON LOCATION AND DURATION OF
THE CONVERGENCE ZONE.

MODIFIED ARCTIC AIR WILL BEGIN SPILLING OUT OF THE FRASER VALLEY
FRIDAY EVENING. IT WILL BECOME VERY WINDY OVER PARTS OF THE N
INTERIOR FROM WHATCOM COUNTY ACROSS THE SAN JUAN ISLANDS. BEST GUESS
IS THAT WINDS WILL END UP IN THE WIND ADVISORY RANGE...BUT SOME
LOCAL HIGH WINDS ARE NOT OUT OF THE QUESTION. A HIGH WIND WATCH HAS
BEEN ISSUED FOR THIS. WITH AIR TEMPERATURES IN THE 20S...WIND CHILLS
WILL END UP IN THE TEENS AND SOME FREEZING SPRAY IS NOT OUT OF THE
QUESTION.

THE MODIFIED ARCTIC AIR WILL SPILL S ACROSS PUGET SOUND AS ANOTHER
COLD FRONT LATE FRIDAY NIGHT AND SATURDAY MORNING...AND SPILL WEST
THROUGH THE STRAIT OF JUAN DE FUCA. MORE WIDESPREAD LIGHT SNOW IS
LIKELY ACROSS THE GREATER PUGET SOUND REGION...AND OVER THE SW
INTERIOR AND OUT TOWARDS THE COAST. AGAIN THE MOST LIKELY OUTCOME IS
AN INCH OR LESS OF SNOW WITH LOCAL AMOUNTS OF A COUPLE OF INCHES.
HOWEVER UNCERTAINTY IS HIGH AND HEAVIER AMOUNTS AROUND 3 INCHES OR
SO ARE POSSIBLE.

OVER THE EASTERN STRAIT OF JUAN DE FUCA AREAS...NE OUTFLOW WINDS
WILL FLOW OVER THE N PART OF THE OLYMPICS...BRINGING UPSLOPE SNOW TO
AREAS ALONG THE STRAIT. THE MOST LIKELY SCENARIO IS FOR AN INCH OR
LESS NEAR THE IMMEDIATE COASTLINE AND POSSIBLY AN INCH OR TWO MORE
OVER THE HIGHER HILLS AWAY FROM THE COASTLINE. ONCE AGAIN
UNCERTAINTY IS HIGH AND AMOUNTS WILL DEPEND UPON HOW MOIST THE AIR
IS AND HOW MUCH UPSLOPE FLOW IS GENERATED.

COLD DRY MODIFIED ARCTIC AIR WILL PRETTY MUCH COVER W WA BY SATURDAY
EVENING WITH CLEARING SKIES. TEMPERATURES WILL DROP INTO THE UPPER
TEENS TO MID 20S BY SUNDAY MORNING. KAM

.LONG TERM...ONLY MINOR CHANGES WERE MADE TO THE LONG TERM
FORECAST...MONDAY THROUGH THURSDAY. THE SET-UP HAS A NORTHERN STREAM
RIDGE OFFSHORE OVER THE NE PACIFIC...WITH COOL NW FLOW ALOFT OVER W
WA. ALSO IN THE PICTURE IS A SOUTHERN STREAM CLOSED LOW W OF THE CA
COAST. WASHINGTON APPEARS TO BE CONTESTED TERRITORY BETWEEN THE
NORTHERN AND SOUTHERN STREAMS WHICH MEANS MODEL BATTLES TO DETERMINE
WHICH STREAM WILL WIN OUT. THE ECMWF HAS BEEN MORE OR LESS
CONSISTENTLY KEEPING THE AREA UNDER THE COOLER DRIER AND SUNNIER N
STREAM THROUGH MID NEXT WEEK. THE GFS HAS BEEN WOBBLING BETWEEN THE
ECMWF SOLUTION AND A WETTER SOUTHERN STREAM SOLUTION. FORECASTS
CONTINUE TO FOLLOW THE ECMWF...BUT CONFIDENCE IS ONLY MODERATE GIVEN
THE MODEL CONFLICTS AND THE OVERALL DIFFICULTY IN RESOLVING A
PATTERN LIKE THIS. MODELS DO AGREE THAT A SHORTWAVE TROUGH WILL MOVE
SE ACROSS THE AREA ON MONDAY. THIS LOOKS DRY AT THIS POINT BUT MORE
CLOUDS AND POSSIBLY SOME LIGHT PRECIP MAY NEED TO BE ADDED TO THE
FORECAST IF MODEL SOLUTIONS CHANGE. KAM

&&

.HYDROLOGY...THERE HAS BEEN A DISTINCT LULL IN RAINFALL TODAY WITH
WASHINGTON PRETTY CLEARLY BETWEEN SYSTEMS. RAINFALL AMOUNTS IN THE
MOUNTAINS HAVE BEEN LIGHTER THAN FORECAST. RIVERS HAVE BEEN STEADY
OR HAVE RISEN SLOWLY IN RESPONSE TO EARLIER RAIN.

THE FRONT THAT IS CURRENTLY IN SOUTHERN BRITISH COLUMBIA IS FORECAST
TO MOVE SOUTH TONIGHT AND TO CONTINUE SOUTH OUT OF THE STATE BY
FRIDAY EVENING. IT WILL BRING ANOTHER 2-4 INCHES OF RAIN TO THE
MOUNTAINS. CURRENT QPF REFLECTS A BLEND OF MESOSCALE MODELS. HEAVY
RAIN WILL REDEVELOP THIS EVENING AND SPREAD SOUTH OVERNIGHT. THE
RAINIEST PERIOD IS 12Z-18Z FRIDAY WHEN 1-1.5 INCHES OF RAIN IS
FORECAST OVER THE CASCADES OF SNOHOMISH AND KING COUNTIES...WITH UP
TO AN INCH OVER THE LOWLANDS OF THOSE COUNTIES. RAIN SHOULD TAPER IN
THE AFTERNOON AS THE AIR MASS COOLS AND DRIES FROM THE NORTH.

THE US ARMY CORPS OF ENGINEERS HAS TAKEN CONTROL OF DAM OPERATION ON
THE SKAGIT AND BAKER RIVERS. AS A RESULT THE SKAGIT RIVER SHOULD
HAVE ONLY MINOR FLOODING ON BOTH THE CONCRETE AND MOUNT VERNON
REACHES. A FLOOD WARNING HAS BEEN POSTED FOR THE SKAGIT RIVER.

THE NOOKSACK RIVER IS ALSO FORECAST TO REACH FLOOD STAGE AT NORTH
CEDARVILLE AND FERNDALE. HOWEVER THE LACK OF HEAVY RAIN TODAY WILL
DELAY ANY FLOODING UNTIL LATE TONIGHT OR FRIDAY.

HEAVY RAIN WILL REACH THE BASINS OF RIVERS FLOWING OFF THE CASCADES
OF SNOHOMISH AND KING COUNTIES LATE TONIGHT AND CONTINUE INTO THE
DAY FRIDAY. A SHEAF OF RIVERS FROM THE STILLAGUAMISH SOUTH TO THE
PUYALLUP NEAR ORTING...INCLUDING THE SKYKOMISH...SNOQUALMIE...
TOLT...AND SNOHOMISH...COULD ALL REACH FLOOD STAGE FROM THIS SHORT
BUT INTENSE BURST OF HEAVY RAIN. ANY FLOODING ON THESE RIVERS IS
EXPECTED TO BE MINOR.

THE SOUTHERN TIER OF RIVERS APPEAR TO BE AT LESS RISK OF FLOODING.
IN THE MODELS THE FRONT SEEMS A BIT SPENT AS IT MOVES INTO THE
SOUTHERN COUNTIES...PIERCE AND LEWIS...AND RAINFALL MAY NOT BE AS
HEAVY AS IN THE NORTHERN COUNTIES. A FLOOD WATCH REMAINS IN EFFECT
FOR ALL COUNTIES FROM WHATCOM TO LEWIS...AS WELL AS MASON COUNTY.

SPEAKING OF MASON COUNTY...THE SKOKOMISH RIVER IS ABOVE FLOOD STAGE
AND WILL LIKELY REMAIN NEAR OR ABOVE FLOOD STAGE THROUGH FRIDAY
NIGHT. THE FLOOD WARNING THERE REMAINS IN EFFECT. BURKE

&&

.AVIATION...THE FLOW ALOFT IS W/SW. THE AIR MASS IS MOIST AND
UNSTABLE. RAIN SHOWERS WILL CONTINUE TONIGHT...WITH MVFR AND VFR
CIGS AT MOST OF THE TERMINALS. A STRONG COLD FRONT WILL MOVE SOUTH
THROUGH THE AREA BETWEEN 10Z AND 17Z EARLY FRIDAY MORNING...AND
WINDS WILL SHARPLY SWITCH FROM S TO NW AT THE TERMINALS. MODERATE
RAIN AND DECREASED VISIBILITIES ARE POSSIBLE WITH CONVERGENCE FROM
THE FRONT. AFTER THE FRONTAL SYSTEM MOVES THROUGH...A PUGET SOUND
CONVERGENCE ZONE MAY FORM OVER PAE FRIDAY NIGHT INTO SATURDAY...AND
TEMPERATURES WILL BE COLD ENOUGH FOR PRECIPITATION TO FALL AS SNOW.
KCLM MAY ALSO BE AFFECTED BY UPSLOPE FLOW OVER THE OLYMPICS.

KSEA...EXPECT RAIN SHOWERS THROUGH TONIGHT...WITH POSSIBLE MODERATE
RAIN EARLY FRIDAY JUST BEFORE THE FRONTAL PASSAGE. GUSTY SOUTH WINDS
WILL CHANGE TO N WITH THE PASSAGE OF THE COLD FRONT AROUND 15Z.
THERE MAY BE A BRIEF PERIOD FOR AN HOUR OR SO WHERE THE WINDS AT BFI
ARE FROM THE N AND WINDS AT SEATAC ARE FROM THE S JUST BEFORE
FRONTAL PASSAGE. THIS MAY ALSO OCCUR AGAIN WHEN SURFACE WINDS SWITCH
TO SOUTH IN THE EARLY AFTERNOON FRIDAY. LATE FRIDAY NIGHT INTO
SATURDAY...THERE IS A CHANCE FOR SNOW AT SEA-TAC WITH MODIFIED
ARCTIC AIR IN THE AREA. AT THIS POINT WE ARE LOOKING AT
ACCUMULATIONS OF AN INCH OR LESS. JSMITH

&&

.MARINE...SMALL CRAFT ADVISORIES ARE IN EFFECT FOR ALL ZONES...WITH
HIGHER PRESSURE IN THE SOUTH AND LOWER PRESSURE IN THE NORTH
PRODUCING HIGH END SMALL CRAFT ADVISORY LEVEL WINDS. PRESSURE
GRADIENTS WILL REMAIN TIGHT TONIGHT THROUGH FRI MORNING AS A WELL
DEVELOPED COLD FRONT SHIFTS SOUTH INTO WESTERN WA. WINDS WILL SWITCH
FROM THE SW TO THE N OR NW AS THE FRONT MOVES THROUGH.

STRONG HIGH PRES OVER INTERIOR B.C. WILL BRING N/NE FRASER RIVER
OUTFLOW WINDS LATE FRI NIGHT INTO SAT AND A GALE WATCH HAS BEEN
ISSUED FOR THE NORTHERN INLAND WATERS AND EAST ENTRANCE TO THE
STRAIT. OFFSHORE FLOW WILL PREVAIL EARLY NEXT WEEK WITH HIGH PRES
EAST OF THE CASCADES. JSMITH

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...FLOOD WATCHES AND WARNINGS IN EFFECT FOR PORTIONS OF
      WESTERN WASHINGTON.
     HIGH WIND WATCH NORTH INTERIOR FRIDAY NIGHT AND SATURDAY.
PZ...GALE WATCH NORTHERN INLAND WATERS AND EAST ENTRANCE STRAIT OF
      JUAN DE FUCA FOR FRIDAY NIGHT AND SATURDAY.
     SMALL CRAFT ADVISORY ALL WATERS.
     SMALL CRAFT ADVISORY GRAYS HARBOR BAR FOR ROUGH 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 280008
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
408 PM PST THU NOV 27 2014

.SYNOPSIS...A COLD FRONT WILL MOVE SOUTH ACROSS WESTERN WA LATE
TONIGHT AND FRIDAY MORNING PRODUCING HEAVY RAIN OVER THE MOUNTAINS
AND OVER PARTS OF THE PUGET SOUND REGION. A CONVERGENCE ZONE WILL
CONTINUE OVER PUGET SOUND FRIDAY NIGHT...THEN ANOTHER COLD FRONT
WITH MODIFIED ARCTIC AIR WILL MOVE SOUTH THROUGH THE AREA LATE
FRIDAY NIGHT INTO SATURDAY MORNING. SOME SNOW OR RAIN AND SNOW MIXED
IS LIKELY TO OCCUR WITH THE CONVERGENCE ZONE AND ALONG THIS SECOND
FRONT. COOL NORTHWEST FLOW ALOFT WILL BRING MAINLY COOL AND DRY
WEATHER SUNDAY THROUGH EARLY NEXT WEEK.

&&

.SHORT TERM...VERY ACTIVE AND CHANGEABLE WEATHER IS EXPECTED OVER
THE AREA THROUGH SATURDAY.

THE WARM FRONT FROM A COUPLE OF DAYS AGO IS STILL UP OVER B.C. AND
POISED TO MOVE BACK S OVER W WA AS A FAIRLY STRONG COLD FRONT
TONIGHT. RECENT MODELS ARE IN FAIRLY GOOD AGREEMENT WITH THE
TIMING...BRINGING THE FRONT TO A N COAST-BLI LINE AT 09Z/1 AM...TO A
HQM-PAE LINE 15Z/7AM...AND TO APPROXIMATELY AN AST-CLS LINE AROUND
19Z/11 AM. RAIN WILL INCREASE TONIGHT AND BE HEAVY IN SOME LOWLAND
AREAS AS WELL AS OVER THE MOUNTAINS. THE AIR MASS WILL REMAIN MOIST
AND MILD WITH LOWLAND TEMPERATURES IN THE 50S.

THE MAIN SHORT TERM PROBLEM IS HEAVY RAIN OVER THE MOUNTAINS WHICH
STILL POSES A FLOODING THREAT TO SOME AREA RIVERS. SEE THE HYDROLOGY
SECTION BELOW FOR MORE DETAIL. THE HEAVY RAIN OVER THE MOUNTAINS
WILL SHUT OFF BEHIND THE COLD FRONT. SOME EARLIER MODELS SHOWED SOME
RATHER HEAVY RAIN OVER OVER THE GREATER PUGET SOUND REGION WITH THE
FRONT...BUT THE NEWEST 12Z RUNS HAVE TAKEN A STEP BACK. THE
HIRES-ARW MODEL REMAINS THE HEAVIEST PRECIP PRODUCER WITH AROUND AN
INCH WITH THE FRONT. THE 12Z NAM12 AND HIRES-NMM MODELS ARE MUCH
LIGHTER. TEMPERATURES WILL REMAIN WARM ENOUGH TO KEEP THE PRECIP ALL
RAIN. TEMPERATURES WILL FALL INTO THE 30S TO LOWER 40S BY LATE
FRIDAY AFTERNOON.

BEHIND THE COLD FRONT A CONVERGENCE ZONE WILL FORM OVER CENTRAL
PUGET SOUND LATE FRIDAY AFTERNOON AND CONTINUE INTO FRIDAY NIGHT.
TEMPERATURES WILL FALL INTO THE LOWER TO MID 30S BY MID EVENING WITH
SNOW LEVELS FALLING BELOW 1000 FEET...SO THE CONVERGENCE ZONE MAY
PRODUCE SOME SNOW FROM NORTH SEATTLE UP THROUGH ARLINGTON. SNOW
ACCUMULATIONS WILL PROBABLY BE AN INCH OR LESS BUT THERE COULD BE
LOCAL HIGHER ACCUMULATIONS DEPENDING UPON LOCATION AND DURATION OF
THE CONVERGENCE ZONE.

MODIFIED ARCTIC AIR WILL BEGIN SPILLING OUT OF THE FRASER VALLEY
FRIDAY EVENING. IT WILL BECOME VERY WINDY OVER PARTS OF THE N
INTERIOR FROM WHATCOM COUNTY ACROSS THE SAN JUAN ISLANDS. BEST GUESS
IS THAT WINDS WILL END UP IN THE WIND ADVISORY RANGE...BUT SOME
LOCAL HIGH WINDS ARE NOT OUT OF THE QUESTION. A HIGH WIND WATCH HAS
BEEN ISSUED FOR THIS. WITH AIR TEMPERATURES IN THE 20S...WIND CHILLS
WILL END UP IN THE TEENS AND SOME FREEZING SPRAY IS NOT OUT OF THE
QUESTION.

THE MODIFIED ARCTIC AIR WILL SPILL S ACROSS PUGET SOUND AS ANOTHER
COLD FRONT LATE FRIDAY NIGHT AND SATURDAY MORNING...AND SPILL WEST
THROUGH THE STRAIT OF JUAN DE FUCA. MORE WIDESPREAD LIGHT SNOW IS
LIKELY ACROSS THE GREATER PUGET SOUND REGION...AND OVER THE SW
INTERIOR AND OUT TOWARDS THE COAST. AGAIN THE MOST LIKELY OUTCOME IS
AN INCH OR LESS OF SNOW WITH LOCAL AMOUNTS OF A COUPLE OF INCHES.
HOWEVER UNCERTAINTY IS HIGH AND HEAVIER AMOUNTS AROUND 3 INCHES OR
SO ARE POSSIBLE.

OVER THE EASTERN STRAIT OF JUAN DE FUCA AREAS...NE OUTFLOW WINDS
WILL FLOW OVER THE N PART OF THE OLYMPICS...BRINGING UPSLOPE SNOW TO
AREAS ALONG THE STRAIT. THE MOST LIKELY SCENARIO IS FOR AN INCH OR
LESS NEAR THE IMMEDIATE COASTLINE AND POSSIBLY AN INCH OR TWO MORE
OVER THE HIGHER HILLS AWAY FROM THE COASTLINE. ONCE AGAIN
UNCERTAINTY IS HIGH AND AMOUNTS WILL DEPEND UPON HOW MOIST THE AIR
IS AND HOW MUCH UPSLOPE FLOW IS GENERATED.

COLD DRY MODIFIED ARCTIC AIR WILL PRETTY MUCH COVER W WA BY SATURDAY
EVENING WITH CLEARING SKIES. TEMPERATURES WILL DROP INTO THE UPPER
TEENS TO MID 20S BY SUNDAY MORNING. KAM

.LONG TERM...ONLY MINOR CHANGES WERE MADE TO THE LONG TERM
FORECAST...MONDAY THROUGH THURSDAY. THE SET-UP HAS A NORTHERN STREAM
RIDGE OFFSHORE OVER THE NE PACIFIC...WITH COOL NW FLOW ALOFT OVER W
WA. ALSO IN THE PICTURE IS A SOUTHERN STREAM CLOSED LOW W OF THE CA
COAST. WASHINGTON APPEARS TO BE CONTESTED TERRITORY BETWEEN THE
NORTHERN AND SOUTHERN STREAMS WHICH MEANS MODEL BATTLES TO DETERMINE
WHICH STREAM WILL WIN OUT. THE ECMWF HAS BEEN MORE OR LESS
CONSISTENTLY KEEPING THE AREA UNDER THE COOLER DRIER AND SUNNIER N
STREAM THROUGH MID NEXT WEEK. THE GFS HAS BEEN WOBBLING BETWEEN THE
ECMWF SOLUTION AND A WETTER SOUTHERN STREAM SOLUTION. FORECASTS
CONTINUE TO FOLLOW THE ECMWF...BUT CONFIDENCE IS ONLY MODERATE GIVEN
THE MODEL CONFLICTS AND THE OVERALL DIFFICULTY IN RESOLVING A
PATTERN LIKE THIS. MODELS DO AGREE THAT A SHORTWAVE TROUGH WILL MOVE
SE ACROSS THE AREA ON MONDAY. THIS LOOKS DRY AT THIS POINT BUT MORE
CLOUDS AND POSSIBLY SOME LIGHT PRECIP MAY NEED TO BE ADDED TO THE
FORECAST IF MODEL SOLUTIONS CHANGE. KAM

&&

.HYDROLOGY...THERE HAS BEEN A DISTINCT LULL IN RAINFALL TODAY WITH
WASHINGTON PRETTY CLEARLY BETWEEN SYSTEMS. RAINFALL AMOUNTS IN THE
MOUNTAINS HAVE BEEN LIGHTER THAN FORECAST. RIVERS HAVE BEEN STEADY
OR HAVE RISEN SLOWLY IN RESPONSE TO EARLIER RAIN.

THE FRONT THAT IS CURRENTLY IN SOUTHERN BRITISH COLUMBIA IS FORECAST
TO MOVE SOUTH TONIGHT AND TO CONTINUE SOUTH OUT OF THE STATE BY
FRIDAY EVENING. IT WILL BRING ANOTHER 2-4 INCHES OF RAIN TO THE
MOUNTAINS. CURRENT QPF REFLECTS A BLEND OF MESOSCALE MODELS. HEAVY
RAIN WILL REDEVELOP THIS EVENING AND SPREAD SOUTH OVERNIGHT. THE
RAINIEST PERIOD IS 12Z-18Z FRIDAY WHEN 1-1.5 INCHES OF RAIN IS
FORECAST OVER THE CASCADES OF SNOHOMISH AND KING COUNTIES...WITH UP
TO AN INCH OVER THE LOWLANDS OF THOSE COUNTIES. RAIN SHOULD TAPER IN
THE AFTERNOON AS THE AIR MASS COOLS AND DRIES FROM THE NORTH.

THE US ARMY CORPS OF ENGINEERS HAS TAKEN CONTROL OF DAM OPERATION ON
THE SKAGIT AND BAKER RIVERS. AS A RESULT THE SKAGIT RIVER SHOULD
HAVE ONLY MINOR FLOODING ON BOTH THE CONCRETE AND MOUNT VERNON
REACHES. A FLOOD WARNING HAS BEEN POSTED FOR THE SKAGIT RIVER.

THE NOOKSACK RIVER IS ALSO FORECAST TO REACH FLOOD STAGE AT NORTH
CEDARVILLE AND FERNDALE. HOWEVER THE LACK OF HEAVY RAIN TODAY WILL
DELAY ANY FLOODING UNTIL LATE TONIGHT OR FRIDAY.

HEAVY RAIN WILL REACH THE BASINS OF RIVERS FLOWING OFF THE CASCADES
OF SNOHOMISH AND KING COUNTIES LATE TONIGHT AND CONTINUE INTO THE
DAY FRIDAY. A SHEAF OF RIVERS FROM THE STILLAGUAMISH SOUTH TO THE
PUYALLUP NEAR ORTING...INCLUDING THE SKYKOMISH...SNOQUALMIE...
TOLT...AND SNOHOMISH...COULD ALL REACH FLOOD STAGE FROM THIS SHORT
BUT INTENSE BURST OF HEAVY RAIN. ANY FLOODING ON THESE RIVERS IS
EXPECTED TO BE MINOR.

THE SOUTHERN TIER OF RIVERS APPEAR TO BE AT LESS RISK OF FLOODING.
IN THE MODELS THE FRONT SEEMS A BIT SPENT AS IT MOVES INTO THE
SOUTHERN COUNTIES...PIERCE AND LEWIS...AND RAINFALL MAY NOT BE AS
HEAVY AS IN THE NORTHERN COUNTIES. A FLOOD WATCH REMAINS IN EFFECT
FOR ALL COUNTIES FROM WHATCOM TO LEWIS...AS WELL AS MASON COUNTY.

SPEAKING OF MASON COUNTY...THE SKOKOMISH RIVER IS ABOVE FLOOD STAGE
AND WILL LIKELY REMAIN NEAR OR ABOVE FLOOD STAGE THROUGH FRIDAY
NIGHT. THE FLOOD WARNING THERE REMAINS IN EFFECT. BURKE

&&

.AVIATION...THE FLOW ALOFT IS W/SW. THE AIR MASS IS MOIST AND
UNSTABLE. RAIN SHOWERS WILL CONTINUE TONIGHT...WITH MVFR AND VFR
CIGS AT MOST OF THE TERMINALS. A STRONG COLD FRONT WILL MOVE SOUTH
THROUGH THE AREA BETWEEN 10Z AND 17Z EARLY FRIDAY MORNING...AND
WINDS WILL SHARPLY SWITCH FROM S TO NW AT THE TERMINALS. MODERATE
RAIN AND DECREASED VISIBILITIES ARE POSSIBLE WITH CONVERGENCE FROM
THE FRONT. AFTER THE FRONTAL SYSTEM MOVES THROUGH...A PUGET SOUND
CONVERGENCE ZONE MAY FORM OVER PAE FRIDAY NIGHT INTO SATURDAY...AND
TEMPERATURES WILL BE COLD ENOUGH FOR PRECIPITATION TO FALL AS SNOW.
KCLM MAY ALSO BE AFFECTED BY UPSLOPE FLOW OVER THE OLYMPICS.

KSEA...EXPECT RAIN SHOWERS THROUGH TONIGHT...WITH POSSIBLE MODERATE
RAIN EARLY FRIDAY JUST BEFORE THE FRONTAL PASSAGE. GUSTY SOUTH WINDS
WILL CHANGE TO N WITH THE PASSAGE OF THE COLD FRONT AROUND 15Z.
THERE MAY BE A BRIEF PERIOD FOR AN HOUR OR SO WHERE THE WINDS AT BFI
ARE FROM THE N AND WINDS AT SEATAC ARE FROM THE S JUST BEFORE
FRONTAL PASSAGE. THIS MAY ALSO OCCUR AGAIN WHEN SURFACE WINDS SWITCH
TO SOUTH IN THE EARLY AFTERNOON FRIDAY. LATE FRIDAY NIGHT INTO
SATURDAY...THERE IS A CHANCE FOR SNOW AT SEA-TAC WITH MODIFIED
ARCTIC AIR IN THE AREA. AT THIS POINT WE ARE LOOKING AT
ACCUMULATIONS OF AN INCH OR LESS. JSMITH

&&

.MARINE...SMALL CRAFT ADVISORIES ARE IN EFFECT FOR ALL ZONES...WITH
HIGHER PRESSURE IN THE SOUTH AND LOWER PRESSURE IN THE NORTH
PRODUCING HIGH END SMALL CRAFT ADVISORY LEVEL WINDS. PRESSURE
GRADIENTS WILL REMAIN TIGHT TONIGHT THROUGH FRI MORNING AS A WELL
DEVELOPED COLD FRONT SHIFTS SOUTH INTO WESTERN WA. WINDS WILL SWITCH
FROM THE SW TO THE N OR NW AS THE FRONT MOVES THROUGH.

STRONG HIGH PRES OVER INTERIOR B.C. WILL BRING N/NE FRASER RIVER
OUTFLOW WINDS LATE FRI NIGHT INTO SAT AND A GALE WATCH HAS BEEN
ISSUED FOR THE NORTHERN INLAND WATERS AND EAST ENTRANCE TO THE
STRAIT. OFFSHORE FLOW WILL PREVAIL EARLY NEXT WEEK WITH HIGH PRES
EAST OF THE CASCADES. JSMITH

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...FLOOD WATCHES AND WARNINGS IN EFFECT FOR PORTIONS OF
      WESTERN WASHINGTON.
     HIGH WIND WATCH NORTH INTERIOR FRIDAY NIGHT AND SATURDAY.
PZ...GALE WATCH NORTHERN INLAND WATERS AND EAST ENTRANCE STRAIT OF
      JUAN DE FUCA FOR FRIDAY NIGHT AND SATURDAY.
     SMALL CRAFT ADVISORY ALL WATERS.
     SMALL CRAFT ADVISORY GRAYS HARBOR BAR FOR ROUGH BAR.

&&

$$

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000
FXUS66 KOTX 272335
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
335 PM PST THU NOV 27 2014

.SYNOPSIS...
A rainy and breezy weather pattern will envelope the region
tonight and Friday but snow levels will remain above pass levels
for motorists traveling on Friday. The arrival of a very cold and
windy arctic front Friday Night into Saturday will bring winter
driving conditions to the mountain passes and much cooler weather
for the weekend. Cold conditions with a few minor snow bearing
weather disturbances are expected as the new work week begins.

.DISCUSSION...
Tonight and Friday...A somewhat complex flow regime is apparent on
satellite this afternoon. Two Pacific moisture feeds are
perceptible...one feeding into southwest Oregon with the northern
fringe of this feed seeping up into the southeastern
Washington/north Idaho zones and the second fetching into
Vancouver Isle. The southern fetch will provide a fuel source for
mainly spotty showers tonight and into Friday morning into the
Palouse area and the Shoshone County mountains. The northern feed
will slump southward and become better directed into the forecast
area tonight and sag further through the remainder of the forecast
area during the day Friday...driven through by an upper level
trough descending down the British Columbia coast and generating a
surface low under it`s dynamic foot over southern British
Columbia. This low is implied by the baroclinic leaf cloud shield
over central BC and Alberta.

Latest GFS and Nam and ECMWF models are in decent agreement in
evolving this flow regime. The BC surface low will move south and
enter the forecast area Friday morning...deepening as it
does...and move down the Washington/Idaho border. It will be
fueled by the northern deep moisture feed as it does. The presence
of this deepening surface low will help spread the precipitation
shield out into the basin...not just the mountains where the fast
westerly flow would imply a strong orographic component.

Thus the forecast for the next 24 hours will become increasingly
wet. All zones will be subject to light rain...with the best
chance for a significant period of rain on Friday over the
eastern and northern portions of the forecast area and over the
Cascades. Snow levels will remain between 5000 and 6000 feet until
the surface low passes to the south Friday night.

Winds will continue to be a dominant issue through Friday with
model soundings suggesting gust potential to 40 to 50 mph over the
exposed terrain of the eastern basin by Friday afternoon. A Wind
Advisory will be issued with the afternoon package for most of
the zones of the eastern basin. This breezy air mass will once
again promote mild temperatures for overnight lows tonight and
Friday high temps. /Fugazzi

Friday night through Sunday: This period will feature a big transition
from wet and mild weather toward cold and dry conditions. As this
transition occurs Friday night into Saturday, anticipate gusty
winds, periods of light to moderate precipitation (mainly in the
form of valley rain and high mountain snow), and concluding with
the potential for brief valley snow and potential for a few inches
within the eastern mountains.

* Synoptic Overview: Arctic air currently resides under the
  upper- level trof over Northern British Columbia. This low will
  pick up momentum during the next 24 hours then rapidly
  accelerate southward through the region Friday night into
  Saturday morning. The low will interact with a stalled frontal
  boundary draped along the International border promoting
  cyclogenesis (deepening surface low) and a strong surface low
  (990-994mb) deepens somewhere along the WA/ID border between
  I-90 and Canadian Border. Intense pressure gradients will setup
  on both sides of the low...first bringing a SW wind threat along
  its southern periphery Friday evening then along its northern
  periphery early Saturday morning into mid afternoon as the low
  sags south and dense arctic air mass floods in from Canada.

* Winds: Strong southwest winds are expected Friday evening and
  night across southeastern WA and into the ID Palouse as well as
  most mountain ridgetops associated with a strengthening low-
  level jet of 45-55 kts. High Res data from UW along with Bufkit
  data indicate the potential for sustained winds of 15-30 mph
  with gusts 35-55 mph for locations across the West Plains,
  Columbia Basin, Palouse, and foothills of the Blue Mtns.
  Mountain gusts from Mission Ridge to the Blue Mtns to the
  Central Panhandle Mtns will also be susceptible to gusts in
  excess of 50 mph. The strongest winds in these areas will be
  between Friday afternoon and Friday evening. Confidence high
  that the winds will exist roughly 2-4K feet above the surface
  but lower if these gusts will surface to valley floors. Data
  suggest a moderate threat and wind advisory has been issued.

* North winds will move into northern WA Friday evening and
  continue into Saturday. The strongest winds will be through the
  Okanogan Valley...spilling into the Waterville Plateau and
  western Basin. Winds of 15-30 mph with gusts to 45 mph are
  anticipated in these areas. With the air mass change so
  dramatic, I anticipate most north to south oriented valleys
  across Nrn WA will experience breezy conditions. Mountains,
  especially with a north aspect, will also feel gusty winds.

* Precipitation: Moderate to locally heavy precipitation will
  fall within the warm sector of the low bringing up to an inch of
  liquid to the mountains of Idaho and a general quarter to three
  quarters of an inch along the Cascade Crest and locations east
  of a line from Colville to Ritzville (outside the typical
  Cascade rain shadow) This will fall as rain below 6000 feet
  initially but snow levels will be crashing to valley floors with
  the arctic frontal passage Friday night. We don`t typically see
  much in the way of snow accumulations with these patterns as the
  deeper moisture gets shoved south before snow levels fall but a
  quick transition to snow will be possible just prior to
  precipitation ending with accumulations generally under an inch.
  A renewed threat for snow will come Saturday mainly focusing
  snow shower activity along the ID Panhandle and East Slopes. At
  this time, snow amounts with this activity will be light with up
  to a few inches in the mountains and less than an inch in the
  valleys. This will be very light and fluffy snow if it falls.

* Temperatures: High temperatures will be in the teens to 20s
  north to 20s and 30s south. Overnight lows will be manageable
  Saturday morning with winds keeping temperatures up somewhat but
  should be very cold Sunday morning single digits to teens)

* Impacts: Moderate to heavy rain and high mountain snow in Idaho Friday
  night. Rapid transition to freezing temperatures Saturday
  morning could result in flash freeze of rain on most roadways.
  Strong winds Friday evening into Saturday could result in
  scattered power outages and difficult travel conditions for high
  profile vehicles. Light snow accumulations possible in the ID
  Panhandle Friday night into Saturday morning. Very cold
  temperatures during the weekend. /sb

Sunday night through Thursday...Sunday night looks on mark with
continued dry and benign conditions as jet stream and associated
stalled front remains to the south and north/northeast flow at low
levels keeps cold air remaining in place. I have lower confidence
in the Monday/Monday night part of the forecast with GFS runs
showing the front/deformation zone to the south moving back
northward as a warm front of sorts that would overrun the cold air
in place allowing for a prolonged period of mostly snow to fall
from it roughly south of a line drawn from the Tri-Cities to Coeur
d` Alene. The ECMWF shows this feature remaining much further
south and not influencing the forecast area and instead shows a
general Northwest to Southeast flow on the east side of the
offshore ridge remaining in place which could steer a minor
shortwave or two down and influence far Southeast Washington and
Northern Idaho with snow but not to the degree or intensity of the
GFS solution. I, and neighboring offices, feel the ECMWF solution
may be the better way to go as it brings back a negatively tilted
ridge that slowly amplifies with an axis close to the coast. The
ridge off the coast solution is what we have had in place for most
of this fall and having it move back in place seems very
reasonable to me. The end result of the ridge moving back in place
would be a gradual slow warming trend as the ridge amplifies and
the axis moves closer to Eastern Washington and Northern Idaho.
Late Thursday the same favored ECMWF depicts an occluded frontal
zone oriented north to south with a well maintained moisture feed
sweeping up in a southwest to northeast trajectory and overrunning
the slightly warmer yet still cold air in place over the area
which should bring moderate snow to many a lowland and mountain
location mostly independent of elevation. The expectation is the
ridge will likely slow this solution and delay front passage until
Friday or Saturday so have not increased pops for Thursday. Stay
tuned to see if this solution holds true. /Pelatti

&&

.AVIATION...
18Z TAFS: Swift westerly flow in the mid levels of the atmosphere
will promote a rain shadow with generally dry conditions this
evening at all TAF sites. Breezy winds this afternoon will
decrease as the boundary layer decouples tonight but swift
southwest flow will above the boundary layer will promote LLWS
over the eastern TAF sites late tonight and early Friday morning.
VFR conditions are expected at all TAF sites except KEAT. At KEAT
where a moist low level air mass remains in a protected valley IFR
conditions are likely to return after 06-08Z and persist until
early Friday afternoon. Winds will increase in a showery air mass
Friday afternoon with gusts to 40 KTS possible at the KPUW and
KGEG TAF sites after 20Z.

NOTE: The VIS sensor at EAT is out of service so amendments to
VIS are not scheduled. the offending sensor replacement is on
order and may be returned to service by Saturday. /MJF


&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        41  50  26  27  10  22 /  30  70  60  20   0   0
Coeur d`Alene  41  49  29  29  11  23 /  40  80 100  20  10   0
Pullman        43  53  31  32  11  25 /  60  90 100  50  10   0
Lewiston       46  57  37  38  21  28 /  50  70  90  60  20   0
Colville       40  47  22  23   4  21 /  40  70  50  10   0   0
Sandpoint      38  45  26  27   8  20 /  70  90 100  20  10   0
Kellogg        39  44  29  30  10  21 /  70  90 100  50  10   0
Moses Lake     41  55  27  29   9  24 /  10  30  20  10   0   0
Wenatchee      41  49  29  30  13  23 /  20  30  10  10   0   0
Omak           37  46  17  19   1  19 /  20  30  10  10   0   0

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Wind Advisory from 1 PM Friday to Midnight PST Friday Night for
     Idaho Palouse.

WA...Wind Advisory from 1 PM Friday to Midnight PST Friday Night for
     Lower Garfield and Asotin Counties-Spokane Area-Upper
     Columbia Basin-Washington Palouse.

&&

$$




000
FXUS66 KPQR 272322
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
321 PM PST THU NOV 27 2014

.SYNOPSIS...A FRONTAL ZONE REMAINS STALLED OVER WESTERN OREGON AND
WILL REMAIN SO THROUGH FRIDAY. ANOTHER UPPER LEVEL DISTURBANCE WILL
RIDE ALONG THE FRONT LATER TONIGHT AND EARLY FRIDAY...LIKELY CAUSING
RAIN TO FILL IN AGAIN ACROSS THE FORECAST AREA. A SHARP COLD FRONT
WILL MOVE SOUTHEAST ACROSS THE REGION FRIDAY NIGHT. THERE WILL BE A
SHARP TEMPERATURE DROP WITH THE PASSAGE OF THIS COLD FRONT...WITH
SNOW LEVELS QUICKLY LOWERING OVERNIGHT. MIXED RAIN/SNOW SHOWERS ARE
EXPECTED IN THE LOWLANDS SATURDAY AS AN UPPER TROUGH PASSES THROUGH.
SNOW ACCUMULATIONS SHOULD BE LIMITED TO THE HILLS AND ABOVE. HIGH
PRESSURE WILL SETTLE IN EAST OF THE CASCADES SATURDAY NIGHT AND
SUNDAY... BRINGING STRONG EAST WINDS THROUGH THE GORGE AND ACROSS THE
PORTLAND METRO AREA. A SYSTEM COMING UP FROM THE SOUTH MAY ATTEMPT TO
SPREAD MOISTURE UP OVER THE COLD AIR EARLY NEXT WEEK... BUT AT THIS
POINT IT APPEARS MOST PRECIPITATION WILL STAY SOUTH OF OUR FORECAST
AREA.

&&

.SHORT TERM...TONIGHT THROUGH SUNDAY...PLENTY OF WEATHER TO TALK
ABOUT...BUT BEFORE TALKING TURKEY WE WOULD LIKE TO SEND OUR BEST
WISHES TO EVERYONE ON THIS THANKSGIVING DAY.

A STALLED FRONTAL ZONE REMAINS DRAPED OVER WESTERN OREGON THIS
AFTERNOON...BRINGING A FAIRLY STEADY LIGHT TO MODERATE RAIN TO THE
LANE COUNTY CASCADES BUT MORE SHOWERY WEATHER TO AREAS NORTH AND
WEST. THIS FRONT DOES NOT HAVE MUCH IN THE WAY OF DYNAMIC SUPPORT...
AS MOST OF THE UPPER LEVEL ENERGY OUTRAN THE FRONT EARLIER THIS
MORNING. HOWEVER ANOTHER VORTMAX IS EXPECTED TO RIDE ALONG THE FRONT
LATER TONIGHT/EARLY FRI...LIKELY CAUSING RAIN TO BECOME MORE
WIDESPREAD AGAIN. DESPITE THE WEAKNESS OF THE FRONT...SOUTH-NORTH
PRESSURE GRADIENTS HAVE BEEN ENOUGH TO PRODUCE SOME GUSTY SOUTH WINDS
WITH SOME VALLEY LOCATIONS REPORTING GUSTS TO 35 MPH THIS AFTERNOON.

MEANWHILE...INFRARED SATELLITE IMAGERY SHOWS A SHARP COLD FRONT
PUSHING SOUTHWARD THROUGH BRITISH COLUMBIA. THE TEMPERATURE GRADIENT
ASSOCIATED WITH THE FRONT IS FAIRLY IMPRESSIVE...AS SOME LOCATIONS IN
CENTRAL BRITISH COLUMBIA HAVE SEEN THEIR TEMPS FALL FROM THE LOWER
30S THROUGH 20S AND INTO THE TEENS AS TODAY HAS PROGRESSED. THIS
FRONT WILL CONTINUE SOUTHWARD...MOVING ACROSS SW WASHINGTON AND NW
OREGON LATE FRI AFTERNOON AND EVENING.

12Z/18Z NAM BUFR SOUNDINGS SUGGEST SOME WEAK MOIST/CONDITIONAL
INSTABILITY AHEAD OF THE FRONT FRIDAY. WOULD NOT BE SURPRISED TO SEE
A COUPLE STRAY LIGHTNING STRIKES ALONG AND AHEAD OF THE FRONT...
ESPECIALLY CONSIDERING THE STRONG FRONTOGENETICAL LIFT ASSOCIATED
WITH THE FRONT. HOWEVER...INSTABILITY IS EXTREMELY MARGINAL SO WE
DECIDED TO LEAVE IT OUT OF THE FORECAST AT THIS POINT...CHANCES ARE
PROBABLY AROUND 5-10 PERCENT FOR ANY GIVEN LOCATION.

SNOW LEVELS ARE PRESENTLY VERY HIGH...WITH TIMBERLINE WEBCAMS SHOWING
RAIN AS HIGH AS 6000-7000 FT ELEVATION. IT WILL BE A MUCH DIFFERENT
STORY FRI NIGHT AS SNOW LEVELS RAPIDLY LOWER BEHIND THE FRONT. 12Z
ECMWF SHOWS 925 MB TEMPS CRASHING FROM +9 DEG C LATE FRI AFTERNOON TO
-1 DEG C SIX HOURS LATER. BY OUR STANDARDS...THAT IS A FAIRLY
IMPRESSIVE DROP. AT THIS POINT...MOST MODEL SOUNDINGS SEEM TO SUPPORT
SOME WET SNOWFLAKES REACHING THE NORTH COAST AND VALLEY FLOOR BY
SATURDAY MORNING. SHALLOW INSTABILITY CONTINUES THROUGH THE DAY
SATURDAY A POSITIVELY TILTED UPPER TROUGH MOVES THROUGH THE PAC NW.
GIVEN 850 MB TEMPS IN THE -7 TO -8 DEG C RANGE...HEAVIER SHOWERS MAY
STILL PRODUCE A MIX OF RAIN AND WET SNOW OR GRAUPEL DOWN TO THE
VALLEY FLOOR. HOWEVER IT APPEARS ACCUMULATING SNOW WILL BE LIMITED TO
ELEVATIONS ABOVE 500 TO 1000 FT...WITH ACCUMULATIONS INCREASING WITH
ELEVATION ABOVE THAT. THE HIGHER WEST HILLS OF PORTLAND AND SOME
HIGHER ELEVATION SUBURBS MAY SEE A SLUSHY INCH OR TWO OF ACCUMULATION
BY THE TIME ALL IS SAID AND DONE. SNOW LEVELS WILL BE A LITTLE HIGHER
FURTHER TO THE SOUTH.

HIGH PRESSURE WILL THEN BUILD IN SATURDAY NIGHT...BECOMING MORE
CENTERED EAST OF THE CASCADES BY SUNDAY. OFFSHORE PRESSURE GRADIENTS
WILL INCREASE SUNDAY...WITH SOME HIGH RESOLUTION MODELS SUGGESTING
KTTD-KDLS PRESSURE GRADIENTS WILL GET TO -10 MB OR POSSIBLY STRONGER.
THIS WOULD BE ENOUGH FOR EAST WINDS GUSTING 60-70 MPH THROUGH THE
GORGE...AND 40-45 MPH GUSTS IN THE PORTLAND METRO AREA. IF MODELS
CONTINUE THIS TREND...A WIND ADVISORY MAY EVENTUALLY BE NEEDED FOR
THE PORTLAND/VANCOUVER METRO. TEMPERATURES WILL BE WELL BELOW NORMAL
SAT/SUN...WITH HIGHS STUCK IN THE 30S IN AND NEAR THE GORGE AND 40S
MOST LOWLAND LOCATIONS ELSEWHERE.  WEAGLE

.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY...STRONG EAST WINDS SHOULD
EASE SOMEWHAT MONDAY AS A NORTHERN STREAM SYSTEM AND ASSOCIATED
WESTERLY FLOW ALOFT SHOULD ERODE THE HIGH PRESSURE CENTER EAST OF THE
CASCADES. THIS SHOULD CUT DOWN THE PRESSURE GRADIENT A BIT...THOUGH
SOME SORT OF EASTERLY FLOW SHOULD LINGER INSIDE THE GORGE. THERE IS A
LOT OF UNCERTAINTY IN REGARDS TO AN UPPER LEVEL LOW WHICH IS FORECAST
TO CUT OFF SOMEWHERE WEST OF CALIFORNIA SUNDAY. THE 12Z/18Z GFS HAVE
BEEN OUTLIERS IN COMPARISON TO THE LAST COUPLE RUNS OF THE ECMWF AND
THE 12Z CANADIAN MODEL...IN BRINGING A SIGNIFICANT BATCH OF
PRECIPITATION BACK NORTHWARD ACROSS OREGON SUN NIGHT/MONDAY THEN
HAVING IT LINGER FOR MUCH OF THE WEEK. MEANWHILE THE LAST COUPLE RUNS
OF THE ECMWF AND GEM KEEP US GENERALLY DRY THROUGH MIDWEEK...WITH
ANOTHER MODERATE SURGE OF EAST WIND TUE/WED. AFTER COLLABORATING WITH
NEIGHBORING OFFICES...THERE WAS A LARGE CONSENSUS THAT THE GFS
SOLUTION SHOULD BE DISCOUNTED FOR NOW...WITH OUR FORECAST FOLLOWING
MORE IN LINE WITH THE 12Z ECMWF SOLUTION. HOWEVER...IF MODELS START
TO TREND MORE TOWARD THE CURRENT GFS SOLUTION...WE MAY NEED TO
CONTEND WITH SNOW OR ICE FOR AT LEAST A PORTION OF THE COLUMBIA
GORGE.  WEAGLE

&&

.AVIATION...EARLY AFTERNOON SATELLITE IMAGERY CLEARLY SHOWS
LOWER-LEVEL CLOUDS HAVE FILLED IN OVER MUCH OF THE FORECAST AREA.
IFR TO MVFR ALONG THE COAST AND A MIX OF MVFR AND VFR IN THE
INTERIOR LOWLANDS. FRONTAL BOUNDARY OVER THE INTERIOR TO REMAIN
NEARLY STATIONARY THROUGH TONIGHT...WITH CONSIDERABLE LOW-LEVEL
MOISTURE. THUS...EXPECT MAINLY MVFR OR LOWER CONDITIONS ACROSS THE
AREA THROUGH TONIGHT. HIGHER TERRAIN...SUCH AS THE OREGON COAST
RANGE...SW WA WILLAPA HILLS AND THE CASCADES WILL REMAIN OBSCURED
THROUGHOUT THE PERIOD. EXPECT PRECIP INTENSITY TO INCREASE
OVERNIGHT INTO FRI MORNING.

KPDX AND APPROACHES...MVFR HAS SPREAD OVER THE TERMINAL AND
APPROACHES EARLY THIS AFTERNOON. LITTLE CHANGE IN OVERALL FLIGHT
CONDITIONS THROUGH FRI MORNING. WEISHAAR

&&

.MARINE...SOLID SMALL CRAFT ADVISORY WIND SPEEDS OVER THE WATERS
EARLY THIS AFTERNOON. LATEST MODEL GUIDANCE SUGGESTS GUSTS TO 25
KT AT TIMES THROUGH FRI MORNING. THERE MAY BE SHORT PERIODS OF
SUB-ADVISORY WIND SPEEDS THROUGH TONIGHT...BUT BELIEVE THIS WILL
BE THE EXCEPTION INSTEAD OF THE RULE. FAVOR THE NAM AND GFS WIND
FIELD THROUGH SAT. A MORE ROBUST COLD FRONT WILL MOVE SOUTH
THROUGH THE COASTAL WATERS LATE FRI AND EARLY FRI EVENING FOR
CONTINUED SMALL CRAFT ADVISORY WIND. THE WIND WILL SWITCH TO THE
NORTHWEST BEHIND THIS FRONT. THE NORTHWEST WINDS WILL EASE ON
SATURDAY...THEN OFFSHORE GAP ENHANCED EAST WINDS WILL DEVELOP
SATURDAY NIGHT AND SUNDAY...LIKELY EXCEEDING SMALL CRAFT ADVISORY
CRITERIA. THE OFFSHORE WIND CONTINUES INTO EARLY NEXT WEEK...BUT
FAVOR THE ECMWF WIND PATTERN. GFS SEEMS TO BE THE ONLY MAJOR MODEL
THAT MOVES A CLOSED LOW OFF THE CALIFORNIA COAST TO THE NORTHEAST
LATE SUN OR SUN NIGHT. THE ECMWF AND GEM KEEP IT NEARLY
STATIONARY.

SEAS HOLDING IN THE 10 TO 13 FT RANGE AND WILL STAY THAT WAY THROUGH
TONIGHT. SEAS THEN CONTINUE TO HOVER AROUND 10 FT INTO SATURDAY...
THEN FALL BELOW 10 FT BY SUNDAY. THE OFFSHORE FLOW LATER THIS WEEKEND
WILL KNOCK DOWN THE SEAS...BUT RESULT IN VERY CHOPPY CONDITIONS.
WEISHAAR

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 8 AM PST SATURDAY FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 8 AM PST SATURDAY
     FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR
     OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 PM PST FRIDAY
     FOR COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60
     NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 4 PM
     PST FRIDAY.

&&

$$

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 272322
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
321 PM PST THU NOV 27 2014

.SYNOPSIS...A FRONTAL ZONE REMAINS STALLED OVER WESTERN OREGON AND
WILL REMAIN SO THROUGH FRIDAY. ANOTHER UPPER LEVEL DISTURBANCE WILL
RIDE ALONG THE FRONT LATER TONIGHT AND EARLY FRIDAY...LIKELY CAUSING
RAIN TO FILL IN AGAIN ACROSS THE FORECAST AREA. A SHARP COLD FRONT
WILL MOVE SOUTHEAST ACROSS THE REGION FRIDAY NIGHT. THERE WILL BE A
SHARP TEMPERATURE DROP WITH THE PASSAGE OF THIS COLD FRONT...WITH
SNOW LEVELS QUICKLY LOWERING OVERNIGHT. MIXED RAIN/SNOW SHOWERS ARE
EXPECTED IN THE LOWLANDS SATURDAY AS AN UPPER TROUGH PASSES THROUGH.
SNOW ACCUMULATIONS SHOULD BE LIMITED TO THE HILLS AND ABOVE. HIGH
PRESSURE WILL SETTLE IN EAST OF THE CASCADES SATURDAY NIGHT AND
SUNDAY... BRINGING STRONG EAST WINDS THROUGH THE GORGE AND ACROSS THE
PORTLAND METRO AREA. A SYSTEM COMING UP FROM THE SOUTH MAY ATTEMPT TO
SPREAD MOISTURE UP OVER THE COLD AIR EARLY NEXT WEEK... BUT AT THIS
POINT IT APPEARS MOST PRECIPITATION WILL STAY SOUTH OF OUR FORECAST
AREA.

&&

.SHORT TERM...TONIGHT THROUGH SUNDAY...PLENTY OF WEATHER TO TALK
ABOUT...BUT BEFORE TALKING TURKEY WE WOULD LIKE TO SEND OUR BEST
WISHES TO EVERYONE ON THIS THANKSGIVING DAY.

A STALLED FRONTAL ZONE REMAINS DRAPED OVER WESTERN OREGON THIS
AFTERNOON...BRINGING A FAIRLY STEADY LIGHT TO MODERATE RAIN TO THE
LANE COUNTY CASCADES BUT MORE SHOWERY WEATHER TO AREAS NORTH AND
WEST. THIS FRONT DOES NOT HAVE MUCH IN THE WAY OF DYNAMIC SUPPORT...
AS MOST OF THE UPPER LEVEL ENERGY OUTRAN THE FRONT EARLIER THIS
MORNING. HOWEVER ANOTHER VORTMAX IS EXPECTED TO RIDE ALONG THE FRONT
LATER TONIGHT/EARLY FRI...LIKELY CAUSING RAIN TO BECOME MORE
WIDESPREAD AGAIN. DESPITE THE WEAKNESS OF THE FRONT...SOUTH-NORTH
PRESSURE GRADIENTS HAVE BEEN ENOUGH TO PRODUCE SOME GUSTY SOUTH WINDS
WITH SOME VALLEY LOCATIONS REPORTING GUSTS TO 35 MPH THIS AFTERNOON.

MEANWHILE...INFRARED SATELLITE IMAGERY SHOWS A SHARP COLD FRONT
PUSHING SOUTHWARD THROUGH BRITISH COLUMBIA. THE TEMPERATURE GRADIENT
ASSOCIATED WITH THE FRONT IS FAIRLY IMPRESSIVE...AS SOME LOCATIONS IN
CENTRAL BRITISH COLUMBIA HAVE SEEN THEIR TEMPS FALL FROM THE LOWER
30S THROUGH 20S AND INTO THE TEENS AS TODAY HAS PROGRESSED. THIS
FRONT WILL CONTINUE SOUTHWARD...MOVING ACROSS SW WASHINGTON AND NW
OREGON LATE FRI AFTERNOON AND EVENING.

12Z/18Z NAM BUFR SOUNDINGS SUGGEST SOME WEAK MOIST/CONDITIONAL
INSTABILITY AHEAD OF THE FRONT FRIDAY. WOULD NOT BE SURPRISED TO SEE
A COUPLE STRAY LIGHTNING STRIKES ALONG AND AHEAD OF THE FRONT...
ESPECIALLY CONSIDERING THE STRONG FRONTOGENETICAL LIFT ASSOCIATED
WITH THE FRONT. HOWEVER...INSTABILITY IS EXTREMELY MARGINAL SO WE
DECIDED TO LEAVE IT OUT OF THE FORECAST AT THIS POINT...CHANCES ARE
PROBABLY AROUND 5-10 PERCENT FOR ANY GIVEN LOCATION.

SNOW LEVELS ARE PRESENTLY VERY HIGH...WITH TIMBERLINE WEBCAMS SHOWING
RAIN AS HIGH AS 6000-7000 FT ELEVATION. IT WILL BE A MUCH DIFFERENT
STORY FRI NIGHT AS SNOW LEVELS RAPIDLY LOWER BEHIND THE FRONT. 12Z
ECMWF SHOWS 925 MB TEMPS CRASHING FROM +9 DEG C LATE FRI AFTERNOON TO
-1 DEG C SIX HOURS LATER. BY OUR STANDARDS...THAT IS A FAIRLY
IMPRESSIVE DROP. AT THIS POINT...MOST MODEL SOUNDINGS SEEM TO SUPPORT
SOME WET SNOWFLAKES REACHING THE NORTH COAST AND VALLEY FLOOR BY
SATURDAY MORNING. SHALLOW INSTABILITY CONTINUES THROUGH THE DAY
SATURDAY A POSITIVELY TILTED UPPER TROUGH MOVES THROUGH THE PAC NW.
GIVEN 850 MB TEMPS IN THE -7 TO -8 DEG C RANGE...HEAVIER SHOWERS MAY
STILL PRODUCE A MIX OF RAIN AND WET SNOW OR GRAUPEL DOWN TO THE
VALLEY FLOOR. HOWEVER IT APPEARS ACCUMULATING SNOW WILL BE LIMITED TO
ELEVATIONS ABOVE 500 TO 1000 FT...WITH ACCUMULATIONS INCREASING WITH
ELEVATION ABOVE THAT. THE HIGHER WEST HILLS OF PORTLAND AND SOME
HIGHER ELEVATION SUBURBS MAY SEE A SLUSHY INCH OR TWO OF ACCUMULATION
BY THE TIME ALL IS SAID AND DONE. SNOW LEVELS WILL BE A LITTLE HIGHER
FURTHER TO THE SOUTH.

HIGH PRESSURE WILL THEN BUILD IN SATURDAY NIGHT...BECOMING MORE
CENTERED EAST OF THE CASCADES BY SUNDAY. OFFSHORE PRESSURE GRADIENTS
WILL INCREASE SUNDAY...WITH SOME HIGH RESOLUTION MODELS SUGGESTING
KTTD-KDLS PRESSURE GRADIENTS WILL GET TO -10 MB OR POSSIBLY STRONGER.
THIS WOULD BE ENOUGH FOR EAST WINDS GUSTING 60-70 MPH THROUGH THE
GORGE...AND 40-45 MPH GUSTS IN THE PORTLAND METRO AREA. IF MODELS
CONTINUE THIS TREND...A WIND ADVISORY MAY EVENTUALLY BE NEEDED FOR
THE PORTLAND/VANCOUVER METRO. TEMPERATURES WILL BE WELL BELOW NORMAL
SAT/SUN...WITH HIGHS STUCK IN THE 30S IN AND NEAR THE GORGE AND 40S
MOST LOWLAND LOCATIONS ELSEWHERE.  WEAGLE

.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY...STRONG EAST WINDS SHOULD
EASE SOMEWHAT MONDAY AS A NORTHERN STREAM SYSTEM AND ASSOCIATED
WESTERLY FLOW ALOFT SHOULD ERODE THE HIGH PRESSURE CENTER EAST OF THE
CASCADES. THIS SHOULD CUT DOWN THE PRESSURE GRADIENT A BIT...THOUGH
SOME SORT OF EASTERLY FLOW SHOULD LINGER INSIDE THE GORGE. THERE IS A
LOT OF UNCERTAINTY IN REGARDS TO AN UPPER LEVEL LOW WHICH IS FORECAST
TO CUT OFF SOMEWHERE WEST OF CALIFORNIA SUNDAY. THE 12Z/18Z GFS HAVE
BEEN OUTLIERS IN COMPARISON TO THE LAST COUPLE RUNS OF THE ECMWF AND
THE 12Z CANADIAN MODEL...IN BRINGING A SIGNIFICANT BATCH OF
PRECIPITATION BACK NORTHWARD ACROSS OREGON SUN NIGHT/MONDAY THEN
HAVING IT LINGER FOR MUCH OF THE WEEK. MEANWHILE THE LAST COUPLE RUNS
OF THE ECMWF AND GEM KEEP US GENERALLY DRY THROUGH MIDWEEK...WITH
ANOTHER MODERATE SURGE OF EAST WIND TUE/WED. AFTER COLLABORATING WITH
NEIGHBORING OFFICES...THERE WAS A LARGE CONSENSUS THAT THE GFS
SOLUTION SHOULD BE DISCOUNTED FOR NOW...WITH OUR FORECAST FOLLOWING
MORE IN LINE WITH THE 12Z ECMWF SOLUTION. HOWEVER...IF MODELS START
TO TREND MORE TOWARD THE CURRENT GFS SOLUTION...WE MAY NEED TO
CONTEND WITH SNOW OR ICE FOR AT LEAST A PORTION OF THE COLUMBIA
GORGE.  WEAGLE

&&

.AVIATION...EARLY AFTERNOON SATELLITE IMAGERY CLEARLY SHOWS
LOWER-LEVEL CLOUDS HAVE FILLED IN OVER MUCH OF THE FORECAST AREA.
IFR TO MVFR ALONG THE COAST AND A MIX OF MVFR AND VFR IN THE
INTERIOR LOWLANDS. FRONTAL BOUNDARY OVER THE INTERIOR TO REMAIN
NEARLY STATIONARY THROUGH TONIGHT...WITH CONSIDERABLE LOW-LEVEL
MOISTURE. THUS...EXPECT MAINLY MVFR OR LOWER CONDITIONS ACROSS THE
AREA THROUGH TONIGHT. HIGHER TERRAIN...SUCH AS THE OREGON COAST
RANGE...SW WA WILLAPA HILLS AND THE CASCADES WILL REMAIN OBSCURED
THROUGHOUT THE PERIOD. EXPECT PRECIP INTENSITY TO INCREASE
OVERNIGHT INTO FRI MORNING.

KPDX AND APPROACHES...MVFR HAS SPREAD OVER THE TERMINAL AND
APPROACHES EARLY THIS AFTERNOON. LITTLE CHANGE IN OVERALL FLIGHT
CONDITIONS THROUGH FRI MORNING. WEISHAAR

&&

.MARINE...SOLID SMALL CRAFT ADVISORY WIND SPEEDS OVER THE WATERS
EARLY THIS AFTERNOON. LATEST MODEL GUIDANCE SUGGESTS GUSTS TO 25
KT AT TIMES THROUGH FRI MORNING. THERE MAY BE SHORT PERIODS OF
SUB-ADVISORY WIND SPEEDS THROUGH TONIGHT...BUT BELIEVE THIS WILL
BE THE EXCEPTION INSTEAD OF THE RULE. FAVOR THE NAM AND GFS WIND
FIELD THROUGH SAT. A MORE ROBUST COLD FRONT WILL MOVE SOUTH
THROUGH THE COASTAL WATERS LATE FRI AND EARLY FRI EVENING FOR
CONTINUED SMALL CRAFT ADVISORY WIND. THE WIND WILL SWITCH TO THE
NORTHWEST BEHIND THIS FRONT. THE NORTHWEST WINDS WILL EASE ON
SATURDAY...THEN OFFSHORE GAP ENHANCED EAST WINDS WILL DEVELOP
SATURDAY NIGHT AND SUNDAY...LIKELY EXCEEDING SMALL CRAFT ADVISORY
CRITERIA. THE OFFSHORE WIND CONTINUES INTO EARLY NEXT WEEK...BUT
FAVOR THE ECMWF WIND PATTERN. GFS SEEMS TO BE THE ONLY MAJOR MODEL
THAT MOVES A CLOSED LOW OFF THE CALIFORNIA COAST TO THE NORTHEAST
LATE SUN OR SUN NIGHT. THE ECMWF AND GEM KEEP IT NEARLY
STATIONARY.

SEAS HOLDING IN THE 10 TO 13 FT RANGE AND WILL STAY THAT WAY THROUGH
TONIGHT. SEAS THEN CONTINUE TO HOVER AROUND 10 FT INTO SATURDAY...
THEN FALL BELOW 10 FT BY SUNDAY. THE OFFSHORE FLOW LATER THIS WEEKEND
WILL KNOCK DOWN THE SEAS...BUT RESULT IN VERY CHOPPY CONDITIONS.
WEISHAAR

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 8 AM PST SATURDAY FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 8 AM PST SATURDAY
     FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR
     OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 PM PST FRIDAY
     FOR COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60
     NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 4 PM
     PST FRIDAY.

&&

$$

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 272226
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
226 PM PST THU NOV 27 2014

.SYNOPSIS...
A rainy and breezy weather pattern will envelope the region
tonight and Friday but snow levels will remain above pass levels
for motorists traveling on Friday. The arrival of a very cold and
windy arctic front Friday Night into Saturday will bring winter
driving conditions to the mountain passes and much cooler weather
for the weekend. Cold conditions with a few minor snow bearing
weather disturbances are expected as the new work week begins.

.DISCUSSION...
Tonight and Friday...A somewhat complex flow regime is apparent on
satellite this afternoon. Two Pacific moisture feeds are
perceptible...one feeding into southwest Oregon with the northern
fringe of this feed seeping up into the southeastern
Washington/north Idaho zones and the second fetching into
Vancouver Isle. The southern fetch will provide a fuel source for
mainly spotty showers tonight and into Friday morning into the
Palouse area and the Shoshone County mountains. The northern feed
will slump southward and become better directed into the forecast
area tonight and sag further through the remainder of the forecast
area during the day Friday...driven through by an upper level
trough descending down the British Columbia coast and generating a
surface low under it`s dynamic foot over southern British
Columbia. This low is implied by the baroclinic leaf cloud shield
over central BC and Alberta.

Latest GFS and Nam and ECMWF models are in decent agreement in
evolving this flow regime. The BC surface low will move south and
enter the forecast area Friday morning...deepening as it
does...and move down the Washington/Idaho border. It will be
fueled by the northern deep moisture feed as it does. The presence
of this deepening surface low will help spread the precipitation
shield out into the basin...not just the mountains where the fast
westerly flow would imply a strong orographic component.

Thus the forecast for the next 24 hours will become increasingly
wet. All zones will be subject to light rain...with the best
chance for a significant period of rain on Friday over the
eastern and northern portions of the forecast area and over the
Cascades. Snow levels will remain between 5000 and 6000 feet until
the surface low passes to the south Friday night.

Winds will continue to be a dominant issue through Friday with
model soundings suggesting gust potential to 40 to 50 mph over the
exposed terrain of the eastern basin by Friday afternoon. A Wind
Advisory will be issued with the afternoon package for most of
the zones of the eastern basin. This breezy air mass will once
again promote mild temperatures for overnight lows tonight and
Friday high temps. /Fugazzi

Friday night through Sunday: This period will feature a big transition
from wet and mild weather toward cold and dry conditions. As this
transition occurs Friday night into Saturday, anticipate gusty
winds, periods of light to moderate precipitation (mainly in the
form of valley rain and high mountain snow), and concluding with
the potential for brief valley snow and potential for a few inches
within the eastern mountains.

* Synoptic Overview: Arctic air currently resides under the
  upper- level trof over Northern British Columbia. This low will
  pick up momentum during the next 24 hours then rapidly
  accelerate southward through the region Friday night into
  Saturday morning. The low will interact with a stalled frontal
  boundary draped along the International border promoting
  cyclogenesis (deepening surface low) and a strong surface low
  (990-994mb) deepens somewhere along the WA/ID border between
  I-90 and Canadian Border. Intense pressure gradients will setup
  on both sides of the low...first bringing a SW wind threat along
  its southern periphery Friday evening then along its northern
  periphery early Saturday morning into mid afternoon as the low
  sags south and dense arctic air mass floods in from Canada.

* Winds: Strong southwest winds are expected Friday evening and
  night across southeastern WA and into the ID Palouse as well as
  most mountain ridgetops associated with a strengthening low-
  level jet of 45-55 kts. High Res data from UW along with Bufkit
  data indicate the potential for sustained winds of 15-30 mph
  with gusts 35-55 mph for locations across the West Plains,
  Columbia Basin, Palouse, and foothills of the Blue Mtns.
  Mountain gusts from Mission Ridge to the Blue Mtns to the
  Central Panhandle Mtns will also be susceptible to gusts in
  excess of 50 mph. The strongest winds in these areas will be
  between Friday afternoon and Friday evening. Confidence high
  that the winds will exist roughly 2-4K feet above the surface
  but lower if these gusts will surface to valley floors. Data
  suggest a moderate threat and wind advisory has been issued.

* North winds will move into northern WA Friday evening and
  continue into Saturday. The strongest winds will be through the
  Okanogan Valley...spilling into the Waterville Plateau and
  western Basin. Winds of 15-30 mph with gusts to 45 mph are
  anticipated in these areas. With the air mass change so
  dramatic, I anticipate most north to south oriented valleys
  across Nrn WA will experience breezy conditions. Mountains,
  especially with a north aspect, will also feel gusty winds.

* Precipitation: Moderate to locally heavy precipitation will
  fall within the warm sector of the low bringing up to an inch of
  liquid to the mountains of Idaho and a general quarter to three
  quarters of an inch along the Cascade Crest and locations east
  of a line from Colville to Ritzville (outside the typical
  Cascade rain shadow) This will fall as rain below 6000 feet
  initially but snow levels will be crashing to valley floors with
  the arctic frontal passage Friday night. We don`t typically see
  much in the way of snow accumulations with these patterns as the
  deeper moisture gets shoved south before snow levels fall but a
  quick transition to snow will be possible just prior to
  precipitation ending with accumulations generally under an inch.
  A renewed threat for snow will come Saturday mainly focusing
  snow shower activity along the ID Panhandle and East Slopes. At
  this time, snow amounts with this activity will be light with up
  to a few inches in the mountains and less than an inch in the
  valleys. This will be very light and fluffy snow if it falls.

* Temperatures: High temperatures will be in the teens to 20s
  north to 20s and 30s south. Overnight lows will be manageable
  Saturday morning with winds keeping temperatures up somewhat but
  should be very cold Sunday morning single digits to teens)

* Impacts: Moderate to heavy rain and high mountain snow in Idaho Friday
  night. Rapid transition to freezing temperatures Saturday
  morning could result in flash freeze of rain on most roadways.
  Strong winds Friday evening into Saturday could result in
  scattered power outages and difficult travel conditions for high
  profile vehicles. Light snow accumulations possible in the ID
  Panhandle Friday night into Saturday morning. Very cold
  temperatures during the weekend. /sb

Sunday night through Thursday...Sunday night looks on mark with
continued dry and benign conditions as jet stream and associated
stalled front remains to the south and north/northeast flow at low
levels keeps cold air remaining in place. I have lower confidence
in the Monday/Monday night part of the forecast with GFS runs
showing the front/deformation zone to the south moving back
northward as a warm front of sorts that would overrun the cold air
in place allowing for a prolonged period of mostly snow to fall
from it roughly south of a line drawn from the Tri-Cities to Coeur
d` Alene. The ECMWF shows this feature remaining much further
south and not influencing the forecast area and instead shows a
general Northwest to Southeast flow on the east side of the
offshore ridge remaining in place which could steer a minor
shortwave or two down and influence far Southeast Washington and
Northern Idaho with snow but not to the degree or intensity of the
GFS solution. I, and neighboring offices, feel the ECMWF solution
may be the better way to go as it brings back a negatively tilted
ridge that slowly amplifies with an axis close to the coast. The
ridge off the coast solution is what we have had in place for most
of this fall and having it move back in place seems very
reasonable to me. The end result of the ridge moving back in place
would be a gradual slow warming trend as the ridge amplifies and
the axis moves closer to Eastern Washington and Northern Idaho.
Late Thursday the same favored ECMWF depicts an occluded frontal
zone oriented north to south with a well maintained moisture feed
sweeping up in a southwest to northeast trajectory and overrunning
the slightly warmer yet still cold air in place over the area
which should bring moderate snow to many a lowland and mountain
location mostly independent of elevation. The expectation is the
ridge will likely slow this solution and delay front passage until
Friday or Saturday so have not increased pops for Thursday. Stay
tuned to see if this solution holds true. /Pelatti

&&

.AVIATION...
18Z TAFS: Swift westerly flow in the mid levels of the atmosphere
will promote a rain shadow with generally dry conditions today at
all TAF sites. Model soundings indicate strong southwest flow
above a morning inversion so LLWS will be included at the eastern
TAF sites until 19-20Z...before these winds mix down to the
surface as breezy and gusty southwest winds especially over the
eastern TAF sites. The KEAT TAF site is in a very protected
location tucked against the cascades and will be slow to mix out
current LIFR conditions...with a brief MVFR break period possible
from 22Z to this evening when IFR conditions will likely return.
The confidence level for this improvement is moderate. A deeper
feed of moisture will move into the region tonight with showers
developing by 12Z over the eastern TAf sites.


NOTE: The VIS sensor at EAT is out of service so amendments to
VIS are not scheduled. the offending sensor replacement is on
order and may be returned to service by Saturday. /MJF


&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        41  50  26  27  10  22 /  30  70  60  20   0   0
Coeur d`Alene  41  49  29  29  11  23 /  40  80 100  20  10   0
Pullman        43  53  31  32  11  25 /  60  90 100  50  10   0
Lewiston       46  57  37  38  21  28 /  50  70  90  60  20   0
Colville       40  47  22  23   4  21 /  40  70  50  10   0   0
Sandpoint      38  45  26  27   8  20 /  70  90 100  20  10   0
Kellogg        39  44  29  30  10  21 /  70  90 100  50  10   0
Moses Lake     41  55  27  29   9  24 /  10  30  20  10   0   0
Wenatchee      41  49  29  30  13  23 /  20  30  10  10   0   0
Omak           37  46  17  19   1  19 /  20  30  10  10   0   0

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Wind Advisory from 1 PM Friday to Midnight PST Friday Night for
     Idaho Palouse.

WA...Wind Advisory from 1 PM Friday to Midnight PST Friday Night for
     Lower Garfield and Asotin Counties-Spokane Area-Upper
     Columbia Basin-Washington Palouse.

&&

$$




000
FXUS66 KOTX 272226
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
226 PM PST THU NOV 27 2014

.SYNOPSIS...
A rainy and breezy weather pattern will envelope the region
tonight and Friday but snow levels will remain above pass levels
for motorists traveling on Friday. The arrival of a very cold and
windy arctic front Friday Night into Saturday will bring winter
driving conditions to the mountain passes and much cooler weather
for the weekend. Cold conditions with a few minor snow bearing
weather disturbances are expected as the new work week begins.

.DISCUSSION...
Tonight and Friday...A somewhat complex flow regime is apparent on
satellite this afternoon. Two Pacific moisture feeds are
perceptible...one feeding into southwest Oregon with the northern
fringe of this feed seeping up into the southeastern
Washington/north Idaho zones and the second fetching into
Vancouver Isle. The southern fetch will provide a fuel source for
mainly spotty showers tonight and into Friday morning into the
Palouse area and the Shoshone County mountains. The northern feed
will slump southward and become better directed into the forecast
area tonight and sag further through the remainder of the forecast
area during the day Friday...driven through by an upper level
trough descending down the British Columbia coast and generating a
surface low under it`s dynamic foot over southern British
Columbia. This low is implied by the baroclinic leaf cloud shield
over central BC and Alberta.

Latest GFS and Nam and ECMWF models are in decent agreement in
evolving this flow regime. The BC surface low will move south and
enter the forecast area Friday morning...deepening as it
does...and move down the Washington/Idaho border. It will be
fueled by the northern deep moisture feed as it does. The presence
of this deepening surface low will help spread the precipitation
shield out into the basin...not just the mountains where the fast
westerly flow would imply a strong orographic component.

Thus the forecast for the next 24 hours will become increasingly
wet. All zones will be subject to light rain...with the best
chance for a significant period of rain on Friday over the
eastern and northern portions of the forecast area and over the
Cascades. Snow levels will remain between 5000 and 6000 feet until
the surface low passes to the south Friday night.

Winds will continue to be a dominant issue through Friday with
model soundings suggesting gust potential to 40 to 50 mph over the
exposed terrain of the eastern basin by Friday afternoon. A Wind
Advisory will be issued with the afternoon package for most of
the zones of the eastern basin. This breezy air mass will once
again promote mild temperatures for overnight lows tonight and
Friday high temps. /Fugazzi

Friday night through Sunday: This period will feature a big transition
from wet and mild weather toward cold and dry conditions. As this
transition occurs Friday night into Saturday, anticipate gusty
winds, periods of light to moderate precipitation (mainly in the
form of valley rain and high mountain snow), and concluding with
the potential for brief valley snow and potential for a few inches
within the eastern mountains.

* Synoptic Overview: Arctic air currently resides under the
  upper- level trof over Northern British Columbia. This low will
  pick up momentum during the next 24 hours then rapidly
  accelerate southward through the region Friday night into
  Saturday morning. The low will interact with a stalled frontal
  boundary draped along the International border promoting
  cyclogenesis (deepening surface low) and a strong surface low
  (990-994mb) deepens somewhere along the WA/ID border between
  I-90 and Canadian Border. Intense pressure gradients will setup
  on both sides of the low...first bringing a SW wind threat along
  its southern periphery Friday evening then along its northern
  periphery early Saturday morning into mid afternoon as the low
  sags south and dense arctic air mass floods in from Canada.

* Winds: Strong southwest winds are expected Friday evening and
  night across southeastern WA and into the ID Palouse as well as
  most mountain ridgetops associated with a strengthening low-
  level jet of 45-55 kts. High Res data from UW along with Bufkit
  data indicate the potential for sustained winds of 15-30 mph
  with gusts 35-55 mph for locations across the West Plains,
  Columbia Basin, Palouse, and foothills of the Blue Mtns.
  Mountain gusts from Mission Ridge to the Blue Mtns to the
  Central Panhandle Mtns will also be susceptible to gusts in
  excess of 50 mph. The strongest winds in these areas will be
  between Friday afternoon and Friday evening. Confidence high
  that the winds will exist roughly 2-4K feet above the surface
  but lower if these gusts will surface to valley floors. Data
  suggest a moderate threat and wind advisory has been issued.

* North winds will move into northern WA Friday evening and
  continue into Saturday. The strongest winds will be through the
  Okanogan Valley...spilling into the Waterville Plateau and
  western Basin. Winds of 15-30 mph with gusts to 45 mph are
  anticipated in these areas. With the air mass change so
  dramatic, I anticipate most north to south oriented valleys
  across Nrn WA will experience breezy conditions. Mountains,
  especially with a north aspect, will also feel gusty winds.

* Precipitation: Moderate to locally heavy precipitation will
  fall within the warm sector of the low bringing up to an inch of
  liquid to the mountains of Idaho and a general quarter to three
  quarters of an inch along the Cascade Crest and locations east
  of a line from Colville to Ritzville (outside the typical
  Cascade rain shadow) This will fall as rain below 6000 feet
  initially but snow levels will be crashing to valley floors with
  the arctic frontal passage Friday night. We don`t typically see
  much in the way of snow accumulations with these patterns as the
  deeper moisture gets shoved south before snow levels fall but a
  quick transition to snow will be possible just prior to
  precipitation ending with accumulations generally under an inch.
  A renewed threat for snow will come Saturday mainly focusing
  snow shower activity along the ID Panhandle and East Slopes. At
  this time, snow amounts with this activity will be light with up
  to a few inches in the mountains and less than an inch in the
  valleys. This will be very light and fluffy snow if it falls.

* Temperatures: High temperatures will be in the teens to 20s
  north to 20s and 30s south. Overnight lows will be manageable
  Saturday morning with winds keeping temperatures up somewhat but
  should be very cold Sunday morning single digits to teens)

* Impacts: Moderate to heavy rain and high mountain snow in Idaho Friday
  night. Rapid transition to freezing temperatures Saturday
  morning could result in flash freeze of rain on most roadways.
  Strong winds Friday evening into Saturday could result in
  scattered power outages and difficult travel conditions for high
  profile vehicles. Light snow accumulations possible in the ID
  Panhandle Friday night into Saturday morning. Very cold
  temperatures during the weekend. /sb

Sunday night through Thursday...Sunday night looks on mark with
continued dry and benign conditions as jet stream and associated
stalled front remains to the south and north/northeast flow at low
levels keeps cold air remaining in place. I have lower confidence
in the Monday/Monday night part of the forecast with GFS runs
showing the front/deformation zone to the south moving back
northward as a warm front of sorts that would overrun the cold air
in place allowing for a prolonged period of mostly snow to fall
from it roughly south of a line drawn from the Tri-Cities to Coeur
d` Alene. The ECMWF shows this feature remaining much further
south and not influencing the forecast area and instead shows a
general Northwest to Southeast flow on the east side of the
offshore ridge remaining in place which could steer a minor
shortwave or two down and influence far Southeast Washington and
Northern Idaho with snow but not to the degree or intensity of the
GFS solution. I, and neighboring offices, feel the ECMWF solution
may be the better way to go as it brings back a negatively tilted
ridge that slowly amplifies with an axis close to the coast. The
ridge off the coast solution is what we have had in place for most
of this fall and having it move back in place seems very
reasonable to me. The end result of the ridge moving back in place
would be a gradual slow warming trend as the ridge amplifies and
the axis moves closer to Eastern Washington and Northern Idaho.
Late Thursday the same favored ECMWF depicts an occluded frontal
zone oriented north to south with a well maintained moisture feed
sweeping up in a southwest to northeast trajectory and overrunning
the slightly warmer yet still cold air in place over the area
which should bring moderate snow to many a lowland and mountain
location mostly independent of elevation. The expectation is the
ridge will likely slow this solution and delay front passage until
Friday or Saturday so have not increased pops for Thursday. Stay
tuned to see if this solution holds true. /Pelatti

&&

.AVIATION...
18Z TAFS: Swift westerly flow in the mid levels of the atmosphere
will promote a rain shadow with generally dry conditions today at
all TAF sites. Model soundings indicate strong southwest flow
above a morning inversion so LLWS will be included at the eastern
TAF sites until 19-20Z...before these winds mix down to the
surface as breezy and gusty southwest winds especially over the
eastern TAF sites. The KEAT TAF site is in a very protected
location tucked against the cascades and will be slow to mix out
current LIFR conditions...with a brief MVFR break period possible
from 22Z to this evening when IFR conditions will likely return.
The confidence level for this improvement is moderate. A deeper
feed of moisture will move into the region tonight with showers
developing by 12Z over the eastern TAf sites.


NOTE: The VIS sensor at EAT is out of service so amendments to
VIS are not scheduled. the offending sensor replacement is on
order and may be returned to service by Saturday. /MJF


&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        41  50  26  27  10  22 /  30  70  60  20   0   0
Coeur d`Alene  41  49  29  29  11  23 /  40  80 100  20  10   0
Pullman        43  53  31  32  11  25 /  60  90 100  50  10   0
Lewiston       46  57  37  38  21  28 /  50  70  90  60  20   0
Colville       40  47  22  23   4  21 /  40  70  50  10   0   0
Sandpoint      38  45  26  27   8  20 /  70  90 100  20  10   0
Kellogg        39  44  29  30  10  21 /  70  90 100  50  10   0
Moses Lake     41  55  27  29   9  24 /  10  30  20  10   0   0
Wenatchee      41  49  29  30  13  23 /  20  30  10  10   0   0
Omak           37  46  17  19   1  19 /  20  30  10  10   0   0

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Wind Advisory from 1 PM Friday to Midnight PST Friday Night for
     Idaho Palouse.

WA...Wind Advisory from 1 PM Friday to Midnight PST Friday Night for
     Lower Garfield and Asotin Counties-Spokane Area-Upper
     Columbia Basin-Washington Palouse.

&&

$$





000
FXUS66 KSEW 271809 RRA
AFDSEW

AREA FORECAST DISCUSSION...UPDATED TO ADD NEW AVIATION SECTION
NATIONAL WEATHER SERVICE SEATTLE WA
1008 AM PST THU NOV 27 2014

.SYNOPSIS...MOIST ONSHORE FLOW WILL GIVE PERIODS OF RAIN TO THE AREA
TODAY. A COLD FRONT WILL MOVE SOUTHEAST ACROSS THE AREA LATE TONIGHT
AND FRIDAY MORNING PRODUCING HEAVY RAIN OVER THE MOUNTAINS AND OVER
PARTS OF THE PUGET SOUND REGION. A CONVERGENCE ZONE WILL CONTINUE
OVER PUGET SOUND FRIDAY NIGHT...THEN ANOTHER COLD FRONT WILL MOVE
SOUTH THROUGH THE AREA LATE FRIDAY NIGHT INTO SATURDAY MORNING. SOME
SNOW OR RAIN AND SNOW MIXED IS LIKELY TO OCCUR WITH THE CONVERGENCE
ZONE AND ALONG THIS SECOND FRONT. COOL NORTHWEST FLOW ALOFT WILL
BRING MAINLY COOL AND DRY WEATHER SUNDAY THROUGH EARLY NEXT WEEK.

&&

.SHORT TERM...VERY ACTIVE AND CHANGEABLE WEATHER IS EXPECTED OVER
THE AREA THROUGH SATURDAY.

MOIST SW FLOW ALOFT AND ONSHORE FLOW WILL CONTINUE TODAY BRINGING
SOME LIGHT RAIN TO THE LOWLANDS AND HEAVY RAIN AT TIMES TO THE
MOUNTAINS. THE AIR MASS WILL REMAIN MOIST AND MILD WITH TEMPERATURES
IN THE 50S TODAY.

THE WARM FRONT FROM A COUPLE OF DAYS AGO IS STILL UP OVER B.C. AND
POISED TO MOVE BACK S OVER W WA AS A FAIRLY STRONG COLD FRONT
TONIGHT. RECENT MODELS ARE IN FAIRLY GOOD AGREEMENT WITH THE
TIMING...BRINGING THE FRONT TO A N COAST-BLI LINE AT 09Z/1 AM...TO A
HQM-SEA LINE 12Z-15Z/4AM-7AM...AND TO AN AST-CLS LINE AROUND 18Z/10
AM. HEAVY RAIN OVER THE MOUNTAINS WILL SHUT OFF BEHIND THE COLD
FRONT. SOME EARLIER MODELS SHOWED SOME RATHER HEAVY RAIN OVER OVER
THE GREATER PUGET SOUND REGION WITH THE FRONT...BUT THE NEWEST 12Z
RUNS HAVE TAKEN A STEP BACK. THE HIRES-ARW MODEL REMAINS THE
HEAVIEST PRECIP PRODUCER WITH AROUND AN INCH IN 3 HOURS WITH THE
FRONT. THE 12Z NAM12 AND HIRES-NMM MODELS ARE MUCH LIGHTER.
TEMPERATURES WILL REMAIN WARM ENOUGH TO KEEP THE PRECIP ALL RAIN.
TEMPERATURES WILL FALL INTO THE 30S TO LOWER 40S BY LATE FRIDAY
AFTERNOON.

BEHIND THE COLD FRONT A CONVERGENCE ZONE WILL FORM OVER CENTRAL
PUGET SOUND LATE FRIDAY AFTERNOON AND CONTINUE INTO FRIDAY NIGHT.
TEMPERATURES WILL FALL INTO THE LOWER TO MID 30S BY MID EVENING SO
THE CONVERGENCE ZONE MAY PRODUCE SOME SNOW FROM NORTH SEATTLE UP
THROUGH ARLINGTON. AT THE SAME TIME MODIFIED ARCTIC AIR WILL BEGIN
SPILLING OUT OF THE FRASER VALLEY. IT WILL BECOME VERY WINDY OVER
PARTS OF THE N INTERIOR FROM WHATCOM COUNTY ACROSS THE SAN JUAN
ISLANDS...BUT IT IS STILL UNCERTAIN WHETHER THE WINDS WILL END UP IN
THE WIND ADVISORY RANGE OR REACH HIGH WIND CRITERIA.

THE MOD-ARCTIC AIR WILL SPILL S ACROSS PUGET SOUND AS ANOTHER COLD
FRONT SATURDAY MORNING...AND SPILL WEST THROUGH THE STRAIT OF JUAN
DE FUCA. THERE IS POTENTIAL FOR A FEW INCHES OF SNOW OVER PUGET
SOUND SATURDAY MORNING AS THE FRONT MOVES S...AND OVER THE STRAIT AS
THE FLOW HITS THE NORTHERN OLYMPICS. THE SNOW WILL SHUT OFF IN THE
AFTERNOON AS THE AIR MASS DRIES OUT. KAM



.LONG TERM...PREVIOUS DISCUSSION FROM THE 330 AM AFD...AFTER A COLD
MORNING ON SUNDAY...EXPECT GRADUALLY MODERATING CONDITIONS LATER
SUNDAY THROUGH EARLY NEXT WEEK. MODELS VERY ON PRECIPITATION THREATS
STARTING MONDAY WITH THE GFS BRINGING SOUTHERN STREAM MOISTURE INTO
OREGON AND FAR SOUTHERN WASHINGTON AND THE ECMWF AND CANADIAN
SOLUTIONS BRINGING A NORTHERN STREAM TROUGH ACROSS THE AREA DURING
THE SAME PERIOD. AT THIS TIME THE DRY FORECAST WAS MAINTAINED BUT
CLOUDS WERE INCREASED. ALBRECHT

&&

.HYDROLOGY...THERE WAS A LULL IN HEAVY RAIN OVER THE CENTRAL
CASCADES LAST NIGHT WHICH ALLOWED THE SNOQUALMIE AND PUYALLUP RIVERS
TO FALL BELOW FLOOD STAGE. FLOOD WARNINGS ON THOSE RIVERS HAVE ENDED
FOR THE TIME BEING.

IN CONTRAST...HEAVY RAIN FELL LAST NIGHT OVER THE SOUTHWEST FACING
SLOPES OF THE OLYMPICS AND THE CASCADES FROM ABOUT THE STILLAGUAMISH
BASIN NORTHWARD. 12-HOUR AMOUNTS RANGE FROM ABOUT ONE INCH IN THE
SOUTH TO TWO INCHES IN THE NORTH. THE SKOKOMISH RIVER IS NOW ABOVE
FLOOD STAGE AND THE WARNING IS OUT. THE NORTH CASCADE RIVERS HAVE
STARTED RISING AGAIN WITH FLOODING ON AT LEAST SOME OF THEM LOOKING
LIKELY THIS EVENING OR TONIGHT.

SIGNIFICANT PRECIPITATION WILL CONTINUE THROUGH FRIDAY...WITH STRONG
OROGRAPHIC FORCING AS SOUTHWESTERLY LOW LEVEL WINDS OF 40 KT OR SO
CONTINUE. THE HEAVIEST PRECIPITATION WILL BE OVER THE OLYMPICS AND
NORTH CASCADES TODAY AND MOST OF TONIGHT...AND THEN THE FRONTAL BAND
AND HEAVIEST RAIN WILL GRADUALLY SHIFT SOUTHWARD ON FRIDAY. THE SNOW
LEVEL WILL BE 5500 TO 7000 FT THROUGH TONIGHT...AND IT SHOULD FALL
GRADUALLY ON FRIDAY AS THE COLD FRONT STARTS TO MOVE SOUTHEAST
THROUGH THE AREA.

IN THE NORTH CASCADES...THE NOOKSACK AND SKAGIT RIVERS CAME CLOSE TO
FLOODING ON WEDNESDAY...AND BOTH FACE A THREAT OF FLOODING IN THIS
EPISODE. IN ADDITION THE STILLAGUAMISH...SKYKOMISH...TOLT...
SNOQUALMIE...AND SNOHOMISH RIVERS -- ALL OF WHICH FLOODED OR NEARLY
FLOODED IN THE PAST COUPLE DAYS -- COULD FLOOD AS WELL. FLOODING ON
THESE CASCADE RIVERS WOULD PROBABLY BEGIN TONIGHT OR FRIDAY. A MAJOR
FLOODING EPISODE IS UNLIKELY...BUT IT WOULD BE NO SURPRISE IF MANY
OF THESE RIVERS HAVE MINOR TO MODERATE FLOODING.

THE CASCADES SOUTH OF THE SNOHOMISH BASIN WILL PROBABLY RECEIVE 2 TO
4 INCHES OF RAIN. MOST OF THAT COULD FALL ON FRIDAY AND SOME MODELS
-- ESPECIALLY THE UW WRF-GFS -- SHOW FAIRLY INTENSE RAINFALL IN THAT
AREA. SO THE RIVERS THERE FACE A THREAT OF FLOODING AS WELL. OF
COURSE SOME OF THEM RECENTLY FLOODED...AND THEY ARE ALL RUNNING
HIGH. A FLOOD WATCH REMAINS IN EFFECT.

THE COLD FRONT WILL MOVE SOUTHEAST OF WESTERN WASHINGTON FRIDAY
NIGHT...WITH COLD AND DRIER WEATHER LIKELY THIS WEEKEND. RIVERS WILL
RECEDE AND THE FLOOD THREAT WILL END FOR THE FORESEEABLE FUTURE.
MCDONNAL/BURKE

&&

.AVIATION...THE FLOW ALOFT IS W/SW. THE AIR MASS IS MOIST AND FAIRLY
UNSTABLE. RAIN SHOWERS WILL CONTINUE THROUGH THE DAY AND INTO
TONIGHT...WITH MVFR AND VFR CIGS AT MOST OF THE TERMINALS. A STRONG
COLD FRONT WILL MOVE SOUTH THROUGH THE AREA BETWEEN 10Z AND 17Z
EARLY FRIDAY MORNING...AND WINDS WILL SHARPLY SWITCH FROM S TO NW AT
THE TERMINALS. MODERATE RAIN AND DECREASED VISIBILITIES ARE POSSIBLE
WITH CONVERGENCE FROM THE FRONT.

KSEA...EXPECT RAIN SHOWERS THROUGH TODAY AND TONIGHT...WITH POSSIBLE
MODERATE RAIN EARLY FRIDAY JUST BEFORE THE FRONTAL PASSAGE. GUSTY
SOUTH WINDS WILL CHANGE TO N WITH THE PASSAGE OF THE COLD FRONT
AROUND 15Z. THERE MAY BE A BRIEF PERIOD FOR AN HOUR OR SO WHERE THE
WINDS AT BFI ARE FROM THE N AND WINDS AT SEATAC ARE FROM THE S JUST
BEFORE FRONTAL PASSAGE. JSMITH

&&

.MARINE...SMALL CRAFT ADVISORIES ARE IN EFFECT FOR ALL ZONES WITH
HIGHER PRESSURE IN THE SOUTH AND LOWER PRESSURE IN THE NORTH
PRODUCING HIGH END SMALL CRAFT ADVISORY LEVEL WINDS. PRESSURE
GRADIENTS WILL REMAIN TIGHT TONIGHT THROUGH FRI MORNING AS A WELL
DEVELOPED COLD FRONT SHIFTS SOUTH INTO WESTERN WA. WINDS WILL SWITCH
FROM THE SW TO THE N OR NW AS THE FRONT MOVES THROUGH.

STRONG HIGH PRES OVER INTERIOR B.C. WILL BRING N/NE FRASER RIVER
OUTFLOW WINDS LATE FRI NIGHT INTO SAT WITH GALES LIKELY OVER THE
NORTHERN INLAND WATERS. OFFSHORE FLOW WILL PREVAIL SUN AND MON WITH
HIGH PRES EAST OF THE CASCADES. JSMITH

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...FLOOD WATCHES AND WARNINGS IN EFFECT FOR PORTIONS OF
      WESTERN WASHINGTON.
PZ...SMALL CRAFT ADVISORY ALL WATERS.
     SMALL CRAFT ADVISORY GRAYS HARBOR BAR FOR ROUGH 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 271809
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
1009 AM PST THU NOV 27 2014

.SYNOPSIS...
Mild and breezy weather is expected Thanksgiving with a few mainly
mountain showers. Snow levels should rise above the mountain
passes. Motorists with plans to travel over the mountain passes
should experience good conditions today through Friday afternoon.
The arrival of a very cold and windy arctic front Friday Night
into Saturday will bring winter driving conditions to the mountain
passes and much cooler weather for the weekend.

&&

.DISCUSSION...
Morning forecast update addresses high temperature forecast for
today and pruning back precipitation probabilities as well as
increasing expected wind speeds on the exposed basin terrain. A
fast westerly flow in the mid levels should promote a well
defined rain shadow off the Cascades...and similarly fast flow in
the lower levels will promote a breezy and gusty day over much of
the region. This well mixed air mass will also allow temperatures
to reach very mild readings today. The exception to all of this
will be the immediate lee of the Cascades in the Columbia River
valley where moist boundary level air is locked under an inversion
and will be slow to scrub in these protected locations despite
swift flow aloft. Still...some gradual improvement is likely this
afternoon with the inversion slowly eroding from the top
down...although any sunbreaks may be brief before nightfall
promotes a return to the soup. /Fugazzi

&&

.AVIATION...
18Z TAFS: Swift westerly flow in the mid levels of the atmosphere
will promote a rain shadow with generally dry conditions today at
all TAF sites. Model soundings indicate strong southwest flow
above a morning inversion so LLWS will be included at the eastern
TAF sites until 19-20Z...before these winds mix down to the
surface as breezy and gusty southwest winds especially over the
eastern TAF sites. The KEAT TAF site is in a very protected
location tucked against the cascades and will be slow to mix out
current LIFR conditions...with a brief MVFR break period possible
from 22Z to this evening when IFR conditions will likely return.
The confidence level for this improvement is moderate. A deeper
feed of moisture will move into the region tonight with showers
developing by 12Z over the eastern TAf sites.


NOTE: The VIS sensor at EAT is out of service so amendments to
VIS are not scheduled. the offending sensor replacement is on
order and may be returned to service by Saturday. /MJF

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        55  41  50  27  27  12 /  10  20  70  60  10   0
Coeur d`Alene  55  41  49  29  29  12 /  20  40  80  90  20  10
Pullman        57  43  53  32  32  16 /  20  30  90  90  50  10
Lewiston       57  46  56  38  38  23 /  10  20  60  70  60  20
Colville       46  40  47  22  22   7 /  20  40  70  60  10   0
Sandpoint      47  38  45  26  26   8 /  40  70  80  90  20  10
Kellogg        48  39  45  30  30  12 /  60  70  90 100  50  10
Moses Lake     57  41  56  27  27  12 /  10  20  30  30  10   0
Wenatchee      48  41  51  29  29  13 /  10  30  20  20  10   0
Omak           47  37  46  16  16   3 /  10  20  30  20  10   0

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&

$$




000
FXUS66 KOTX 271809
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
1009 AM PST THU NOV 27 2014

.SYNOPSIS...
Mild and breezy weather is expected Thanksgiving with a few mainly
mountain showers. Snow levels should rise above the mountain
passes. Motorists with plans to travel over the mountain passes
should experience good conditions today through Friday afternoon.
The arrival of a very cold and windy arctic front Friday Night
into Saturday will bring winter driving conditions to the mountain
passes and much cooler weather for the weekend.

&&

.DISCUSSION...
Morning forecast update addresses high temperature forecast for
today and pruning back precipitation probabilities as well as
increasing expected wind speeds on the exposed basin terrain. A
fast westerly flow in the mid levels should promote a well
defined rain shadow off the Cascades...and similarly fast flow in
the lower levels will promote a breezy and gusty day over much of
the region. This well mixed air mass will also allow temperatures
to reach very mild readings today. The exception to all of this
will be the immediate lee of the Cascades in the Columbia River
valley where moist boundary level air is locked under an inversion
and will be slow to scrub in these protected locations despite
swift flow aloft. Still...some gradual improvement is likely this
afternoon with the inversion slowly eroding from the top
down...although any sunbreaks may be brief before nightfall
promotes a return to the soup. /Fugazzi

&&

.AVIATION...
18Z TAFS: Swift westerly flow in the mid levels of the atmosphere
will promote a rain shadow with generally dry conditions today at
all TAF sites. Model soundings indicate strong southwest flow
above a morning inversion so LLWS will be included at the eastern
TAF sites until 19-20Z...before these winds mix down to the
surface as breezy and gusty southwest winds especially over the
eastern TAF sites. The KEAT TAF site is in a very protected
location tucked against the cascades and will be slow to mix out
current LIFR conditions...with a brief MVFR break period possible
from 22Z to this evening when IFR conditions will likely return.
The confidence level for this improvement is moderate. A deeper
feed of moisture will move into the region tonight with showers
developing by 12Z over the eastern TAf sites.


NOTE: The VIS sensor at EAT is out of service so amendments to
VIS are not scheduled. the offending sensor replacement is on
order and may be returned to service by Saturday. /MJF

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        55  41  50  27  27  12 /  10  20  70  60  10   0
Coeur d`Alene  55  41  49  29  29  12 /  20  40  80  90  20  10
Pullman        57  43  53  32  32  16 /  20  30  90  90  50  10
Lewiston       57  46  56  38  38  23 /  10  20  60  70  60  20
Colville       46  40  47  22  22   7 /  20  40  70  60  10   0
Sandpoint      47  38  45  26  26   8 /  40  70  80  90  20  10
Kellogg        48  39  45  30  30  12 /  60  70  90 100  50  10
Moses Lake     57  41  56  27  27  12 /  10  20  30  30  10   0
Wenatchee      48  41  51  29  29  13 /  10  30  20  20  10   0
Omak           47  37  46  16  16   3 /  10  20  30  20  10   0

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&

$$





000
FXUS66 KPQR 271752
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
950 AM PST THU NOV 27 2014

.SYNOPSIS...A WEAK COLD FRONT WILL PUSH SLOWLY INLAND TODAY. THE
FRONT WILL THEN STALL OVER SOUTH-CENTRAL OREGON TONIGHT AND FRI. THIS
FRONT WILL BEGIN TO LIFT NORTHWARD AGAIN EARLY FRI. ANOTHER STRONGER
COLD FRONT WILL MOVE S THROUGH THE REGION LATE FRI INTO SAT. THIS
FRONT WILL USHER IN MUCH COLDER WEATHER. SNOW LEVELS WILL FALL
RAPIDLY FRI NIGHT AND SAT...WITH A RAIN/SNOW MIX A POSSIBILITY FOR
THE INTERIOR LOWLANDS. HIGH PRES OVER THE INTERIOR NW WILL TURN THE
FLOW OFFSHORE BY SUN FOR DRY AND COLD WEATHER. ANOTHER SYSTEM COMING
UP FROM THE S SOMETIME EARLY NEXT WEEK WILL ATTEMPT TO SPREAD SOME
PRECIPITATION UP OVER THE COLD AIR MASS LEFT OVER FROM THE WEEKEND.

&&

.MORNING UPDATE...VERY FEW CHANGES WERE MADE TO THE EARLY MORNING
FORECAST PACKAGE...AS IT APPEARS TO BE TRACKING WELL.

THE 12Z SALEM SOUNDING WAS NOTABLE IN SHOWING A BIT OF ELEVATED
INSTABILITY...WITH ABOUT 150-200 J/KG OF SKINNY CAPE DUE THE MILD AND
MOIST AIR MASS BETWEEN 850-700 MB. SURE ENOUGH...THERE ARE SPORADIC
LIGHTNING STRIKES BEING DETECTED NEAR THE SOUTH OREGON COAST. IT
APPEARS THE BEST INSTABILITY SHOULD REMAIN THERE...THOUGH IT WOULD
NOT BE A COMPLETE SURPRISE TO SEE A STRAY LIGHTNING STRIKE OR TWO
SOUTH OF SALEM TODAY. 12Z NAM BUFR SOUNDINGS CONTINUE TO SHOW SKINNY
CAPE INTO FRIDAY...WHEN THERE MAY BE A SLIGHTLY BETTER CHANCE OF
THUNDER ALONG/AHEAD AS THE VIGOROUS COLD FRONT PROVIDES A BIT OF
EXTRA LIFT. THERE IS ALSO SOME FAIRLY DECENT SHEAR WITHIN THIS AREA
OF CONDITIONAL INSTABILITY. HAVE NOT ADDED THIS TO THE FORECAST
YET...BUT WE MAY ADD A SLIGHT CHANCE OF THUNDER FRIDAY WITH THE
AFTERNOON PACKAGE IF SUBSEQUENT MODEL RUNS CONTINUE TO SHOW THIS.

AS FAR AS THE POTENTIAL FOR LOW ELEVATION SNOW LATER FRI NIGHT
THROUGH SAT EVENING...PREVIOUS DISCUSSION BELOW CONTINUES TO REFLECT
CURRENT THINKING...SO NO CHANGES WERE MADE.  WEAGLE

/PREV DISC ISSUED 327 AM PST THU NOV 27 2014/

.SHORT TERM...TODAY THROUGH SATURDAY...BREEZY SOUTHERLY WINDS AHEAD
OF AN APPROACHING COLD FRONT ARE KEEPING EXCEPTIONALLY MILD
CONDITIONS IN PLACE ACROSS SOUTHWEST OREGON AND NORTHWEST OREGON
THIS MORNING. IN FACT...THE TEMPS IN THE UPPER 50S TO LOW 60S BEING
OBSERVED ACROSS MUCH OF THE REGION AT CURRENT ARE VERY CLOSE TO THE
RECORD DAILY HIGH TEMPS FOR THE LAST WEEK OF NOVEMBER. HOWEVER...THE
PERIOD OF MILD WEATHER THAT WE HAVE BEEN EXPERIENCING OVER THE PAST
FEW DAYS WILL BE COMING TO AN END VERY SHORTLY.

THE COLD FRONT APPROACHING THE COAST THIS MORNING IS NOT TERRIBLY
IMPRESSIVE. LOOKING AT THE LATEST IR SATELLITE IMAGERY...IT IS
APPARENT THAT THE UPPER LEVEL FRONT AND ASSOCIATED MOISTURE HAS MOVED
OUT AHEAD OF THE SURFACE FRONTAL BOUNDARY. THE SURFACE FRONT CAN BE
MADE OUT ON SATELLITE JUST OFFSHORE AROUND BUOY 29. WITH ONLY SHALLOW
MOISTURE REMAINING AND LITTLE IN THE WAY OF FORCING ALOFT...THE
ASSOCIATED PRECIPITATION THAT IS MOVING ONSHORE IS DEFINITELY ON THE
PATCHIER SIDE. THE RAIN HAS BECOME A BIT STEADIER OVER THE PAST FEW
HOURS ALONG THE N COAST AND COAST RANGE...BUT MOST SITES ARE ONLY
PICKING UP A FEW HUNDREDTHS OF AN INCH OF RAIN PER HOUR. STILL...
EXPECT MOST LOCATIONS WILL SEE A DECENT STEADY RAIN AS THE FRONT
PUSHES ONSHORE THIS MORNING AND THEN MOVES INLAND THROUGH THE DAY.
THE FRONT WILL EVENTUALLY STALL OVER SOUTHERN AND CENTRAL OREGON
LATER THIS AFTERNOON AND THIS EVENING.

THE OTHER FEATURE OF INTEREST THAT WE ARE WATCHING THIS MORNING IS A
PERSISTENT STATIONARY BAROCLINIC ZONE THAT IS CURRENTLY DRAPED OVER
BRITISH COLUMBIA AND FAR NORTHERN WASHINGTON. AN UPPER LEVEL TROUGH
WILL DRIVE THIS BOUNDARY SOUTHWARD FRI AND FRI NIGHT AS A SHARP COLD
FRONT. AT THE SAME TIME...THE STALLED FRONT OVER CENTRAL OREGON IS
FCST TO PUSH NORTHWARD AGAIN FRI MORNING. BETWEEN THESE TWO FRONTAL
BOUNDARIES...EXPECT RAINFALL TO STEADILY INCREASE AS THE DAY
PROGRESSES FRI. AS THE SHARP COLD FRONT FROM THE NORTH DIVES
THROUGH THE REGION LATER FRI AND FRI NIGHT...A MUCH COLDER AIR MASS
ALOFT WILL MOVE INTO THE REGION.

THE PARENT UPPER LEVEL TROUGH WILL SWING INTO THE REGION FROM THE
NORTH ON SAT TO PROVIDE SOME UPPER LEVEL SUPPORT FOR POST FRONTAL
SHOWER ACTIVITY...WHILE LOW LEVEL ONSHORE FLOW SHOULD PROVIDE
ADDITIONAL MOISTURE TO KEEP SHOWERS GOING THROUGH MUCH OF THE DAY.
BASED ON MODEL 850MB TEMPS AND 1000-500 MB THICKNESS VALUES...IT
APPEARS THAT THERE IS THE POTENTIAL FOR A RAIN/SNOW MIX TO AFFECT THE
INTERIOR LOWLANDS AT TIMES ON SAT. THE TEMP AND THICKNESS INDICATORS
ARE ONLY MARGINAL AND THERE IS SOME UNCERTAINTY AMONGST THE MODELS
JUST HOW COLD THE AIR MASS WILL BE...SO CONFIDENCE IS NOT ALL THAT
HIGH THAT THE INTERIOR LOWLANDS WILL SEE ANY SIGNIFICANT FLAKES. AT
ANY RATE...WITH THE MILD TEMPS WE HAVE SEEN OVER THE PAST FEW DAYS IT
IS UNLIKELY THAT ROAD SURFACES WILL BE ABLE TO COOL FAST ENOUGH FOR
THERE TO BE MAJOR TRAVEL CONCERNS. PYLE


LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY...MOST GUIDANCE
SUGGESTS THE UPPER TROUGH AXIS RESPONSIBLE FOR SATURDAYS SHOWERS WILL
BE MOVING ACROSS THE CASCADES SAT NIGHT...  WITH ANY LINGERING SHOWERS
COMING TO END OVERNIGHT. EXPECT SOME CLEARING SAT NIGHT AS COLD HIGH
PRESSURE BUILDS DOWN FROM BRITISH COLUMBIA...WITH LOW TEMPS LIKELY
GETTING WELL INTO THE 20S FOR MOST SPOTS. WITH HIGH PRESSURE
STRENGTHENING EAST OF THE CASCADES...EXPECT STRONG EAST WINDS TO RAMP
UP THROUGH THE GORGE SUNDAY MORNING AND PERSIST FOR MUCH OF THE
PERIOD THROUGH WEDNESDAY...WITH BREEZY CONDITIONS SPILLING INTO THE
PORTLAND/VANCOUVER METRO. MONDAY MAY BE A BRIEF BREAK FROM THE WINDS
AS A SYSTEM PASSES BY TO OUR NORTH.

MEANWHILE...A DISTURBANCE FROM THE ALEUTIANS IS EXPECTED TO CUT OFF
FROM THE MAIN PACIFIC JET AND SETTLE OFF THE CALIFORNIA COAST BY
SUNDAY...WHERE IT WILL LIKELY LINGER FOR A COUPLE DAYS. THERE IS A
CHANCE THIS SYSTEM COULD COME CLOSE ENOUGH TO SPREAD SOME PRECIP
NORTHWARD INTO OUR FORECAST AREA EARLY NEXT WEEK. IF THIS
OCCURS...THERE MAY BE SOME LIGHT FREEZING RAIN IN PORTIONS OF THE
WILLAMETTE VALLEY WITH SOME SNOW OR LIGHT FREEZING RAIN IN THE
GORGE. CUTOFF LOWS SUCH AS THIS ONE ARE NOTORIOUSLY DIFFICULT TO
FORECAST...AS MODELS STRUGGLE WITH THEM IN THE EXTENDED FORECAST
PERIOD. WHERE THIS UPPER LOW GOES WILL DICTATE THE WEATHER THROUGH
MIDWEEK...BUT TEMPS ARE EXPECTED TO SLOWLY MODERATE TUESDAY AND
WEDNESDAY.  WEAGLE

&&

.AVIATION...GENERALLY A MIX OF IFR TO VFR CONDITIONS ALONG THE
COAST...AND VFR OVER THE INTERIOR LOWLANDS. FRONTAL BOUNDARY
EXPECTED TO WEAKEN AND STALL OVER THE INTERIOR TODAY...WITH PLENTY
OF LOW-LEVEL MOISTURE. THUS...EXPECT MAINLY MVFR OR LOWER
CONDITIONS ACROSS THE AREA THROUGH TONIGHT. HIGHER TERRAIN...SUCH
AS THE OREGON COAST RANGE...SW WA WILLAPA HILLS AND THE CASCADES
WILL REMAIN OBSCURED THROUGHOUT THE PERIOD. EXPECT PRECIP
INTENSITY TO INCREASE OVERNIGHT INTO FRI MORNING.

KPDX AND APPROACHES...VFR CONDITIONS AS OF 16Z...BUT STILL EXPECT
MVFR TO BE THE PREDOMINANT CATEGORY AFTER 18Z. LITTLE CHANGE IN
OVERALL FLIGHT CATEGORY THIS AFTERNOON THROUGH TONIGHT. 12Z SALEM
UPPER AIR SOUNDING AND MODEL SOUNDINGS FOR KPDX INDICATED SE-S
WIND OF AROUND 10 KT AT THE SURFACE...BUT SW WIND 35-40 KT AT
FL020. THIS HAS PRODUCED LLWS NEAR THE AIR FIELD SO HAVE INCLUDED
IT IN THE TAF FOR THIS MORNING. WEISHAAR

&&

.MARINE...GALE FORCE WIND HAS DIMINISHED TO SMALL CRAFT ADVISORY
SPEEDS. MODELS SUGGEST GUSTS TO 25 KT AT TIMES MOST OF THE DAY.
THERE MAY BE SHORT PERIOD OF SUB-ADVISORY WIND SPEEDS THROUGH
TONIGHT...BUT WILL KEEP THE CURRENT SMALL CRAFT ADVISORY AS IS. A
MORE ROBUST COLD FRONT...WHICH HAS MUCH COLDER AIR BEHIND IT...WILL
MOVE SOUTH THROUGH THE COASTAL WATERS LATE FRI AND EARLY FRI EVENING
FOR CONTINUED SMALL CRAFT ADVISORY WINDS. THE WIND WILL SWITCH TO
THE NORTHWEST BEHIND THIS FRONT. THE NORTHWEST WINDS WILL EASE ON
SATURDAY...THEN OFFSHORE GAP ENHANCED EAST WINDS WILL DEVELOP
SATURDAY NIGHT AND SUNDAY...PROBABLY OF THE SMALL CRAFT ADVISORY
VARIETY. THESE OFFSHORE WINDS WILL CONTINUE INTO NEXT WEEK.

SEAS ARE UP TO 10 TO 13 FT THIS MORNING AND WILL REMAIN IN THAT
RANGE THROUGH TONIGHT. SEAS CONTINUE TO HOVER AROUND 10 FT INTO
SATURDAY...THEN FALL BELOW 10 FT BY SUNDAY. SEAS TODAY WILL BE
CHOPPY WITH AROUND 8 SECOND PERIODS FROM THE SOUTHWEST. PERIODS
WILL LENGTHEN TO AROUND 14 SECONDS LATER TODAY AND TONIGHT...THEN
SHIFT AND BE FROM THE NORTHWEST WITH PERIODS AND 10 OR 11 SECONDS
FRIDAY NIGHT INTO SATURDAY. WEISHAAR

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 8 AM PST SATURDAY FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT
     60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 8 AM PST SATURDAY
     FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR
     OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 PM PST FRIDAY
     FOR COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60
     NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 6 AM
     PST FRIDAY.

&&

$$

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 271752
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
950 AM PST THU NOV 27 2014

.SYNOPSIS...A WEAK COLD FRONT WILL PUSH SLOWLY INLAND TODAY. THE
FRONT WILL THEN STALL OVER SOUTH-CENTRAL OREGON TONIGHT AND FRI. THIS
FRONT WILL BEGIN TO LIFT NORTHWARD AGAIN EARLY FRI. ANOTHER STRONGER
COLD FRONT WILL MOVE S THROUGH THE REGION LATE FRI INTO SAT. THIS
FRONT WILL USHER IN MUCH COLDER WEATHER. SNOW LEVELS WILL FALL
RAPIDLY FRI NIGHT AND SAT...WITH A RAIN/SNOW MIX A POSSIBILITY FOR
THE INTERIOR LOWLANDS. HIGH PRES OVER THE INTERIOR NW WILL TURN THE
FLOW OFFSHORE BY SUN FOR DRY AND COLD WEATHER. ANOTHER SYSTEM COMING
UP FROM THE S SOMETIME EARLY NEXT WEEK WILL ATTEMPT TO SPREAD SOME
PRECIPITATION UP OVER THE COLD AIR MASS LEFT OVER FROM THE WEEKEND.

&&

.MORNING UPDATE...VERY FEW CHANGES WERE MADE TO THE EARLY MORNING
FORECAST PACKAGE...AS IT APPEARS TO BE TRACKING WELL.

THE 12Z SALEM SOUNDING WAS NOTABLE IN SHOWING A BIT OF ELEVATED
INSTABILITY...WITH ABOUT 150-200 J/KG OF SKINNY CAPE DUE THE MILD AND
MOIST AIR MASS BETWEEN 850-700 MB. SURE ENOUGH...THERE ARE SPORADIC
LIGHTNING STRIKES BEING DETECTED NEAR THE SOUTH OREGON COAST. IT
APPEARS THE BEST INSTABILITY SHOULD REMAIN THERE...THOUGH IT WOULD
NOT BE A COMPLETE SURPRISE TO SEE A STRAY LIGHTNING STRIKE OR TWO
SOUTH OF SALEM TODAY. 12Z NAM BUFR SOUNDINGS CONTINUE TO SHOW SKINNY
CAPE INTO FRIDAY...WHEN THERE MAY BE A SLIGHTLY BETTER CHANCE OF
THUNDER ALONG/AHEAD AS THE VIGOROUS COLD FRONT PROVIDES A BIT OF
EXTRA LIFT. THERE IS ALSO SOME FAIRLY DECENT SHEAR WITHIN THIS AREA
OF CONDITIONAL INSTABILITY. HAVE NOT ADDED THIS TO THE FORECAST
YET...BUT WE MAY ADD A SLIGHT CHANCE OF THUNDER FRIDAY WITH THE
AFTERNOON PACKAGE IF SUBSEQUENT MODEL RUNS CONTINUE TO SHOW THIS.

AS FAR AS THE POTENTIAL FOR LOW ELEVATION SNOW LATER FRI NIGHT
THROUGH SAT EVENING...PREVIOUS DISCUSSION BELOW CONTINUES TO REFLECT
CURRENT THINKING...SO NO CHANGES WERE MADE.  WEAGLE

/PREV DISC ISSUED 327 AM PST THU NOV 27 2014/

.SHORT TERM...TODAY THROUGH SATURDAY...BREEZY SOUTHERLY WINDS AHEAD
OF AN APPROACHING COLD FRONT ARE KEEPING EXCEPTIONALLY MILD
CONDITIONS IN PLACE ACROSS SOUTHWEST OREGON AND NORTHWEST OREGON
THIS MORNING. IN FACT...THE TEMPS IN THE UPPER 50S TO LOW 60S BEING
OBSERVED ACROSS MUCH OF THE REGION AT CURRENT ARE VERY CLOSE TO THE
RECORD DAILY HIGH TEMPS FOR THE LAST WEEK OF NOVEMBER. HOWEVER...THE
PERIOD OF MILD WEATHER THAT WE HAVE BEEN EXPERIENCING OVER THE PAST
FEW DAYS WILL BE COMING TO AN END VERY SHORTLY.

THE COLD FRONT APPROACHING THE COAST THIS MORNING IS NOT TERRIBLY
IMPRESSIVE. LOOKING AT THE LATEST IR SATELLITE IMAGERY...IT IS
APPARENT THAT THE UPPER LEVEL FRONT AND ASSOCIATED MOISTURE HAS MOVED
OUT AHEAD OF THE SURFACE FRONTAL BOUNDARY. THE SURFACE FRONT CAN BE
MADE OUT ON SATELLITE JUST OFFSHORE AROUND BUOY 29. WITH ONLY SHALLOW
MOISTURE REMAINING AND LITTLE IN THE WAY OF FORCING ALOFT...THE
ASSOCIATED PRECIPITATION THAT IS MOVING ONSHORE IS DEFINITELY ON THE
PATCHIER SIDE. THE RAIN HAS BECOME A BIT STEADIER OVER THE PAST FEW
HOURS ALONG THE N COAST AND COAST RANGE...BUT MOST SITES ARE ONLY
PICKING UP A FEW HUNDREDTHS OF AN INCH OF RAIN PER HOUR. STILL...
EXPECT MOST LOCATIONS WILL SEE A DECENT STEADY RAIN AS THE FRONT
PUSHES ONSHORE THIS MORNING AND THEN MOVES INLAND THROUGH THE DAY.
THE FRONT WILL EVENTUALLY STALL OVER SOUTHERN AND CENTRAL OREGON
LATER THIS AFTERNOON AND THIS EVENING.

THE OTHER FEATURE OF INTEREST THAT WE ARE WATCHING THIS MORNING IS A
PERSISTENT STATIONARY BAROCLINIC ZONE THAT IS CURRENTLY DRAPED OVER
BRITISH COLUMBIA AND FAR NORTHERN WASHINGTON. AN UPPER LEVEL TROUGH
WILL DRIVE THIS BOUNDARY SOUTHWARD FRI AND FRI NIGHT AS A SHARP COLD
FRONT. AT THE SAME TIME...THE STALLED FRONT OVER CENTRAL OREGON IS
FCST TO PUSH NORTHWARD AGAIN FRI MORNING. BETWEEN THESE TWO FRONTAL
BOUNDARIES...EXPECT RAINFALL TO STEADILY INCREASE AS THE DAY
PROGRESSES FRI. AS THE SHARP COLD FRONT FROM THE NORTH DIVES
THROUGH THE REGION LATER FRI AND FRI NIGHT...A MUCH COLDER AIR MASS
ALOFT WILL MOVE INTO THE REGION.

THE PARENT UPPER LEVEL TROUGH WILL SWING INTO THE REGION FROM THE
NORTH ON SAT TO PROVIDE SOME UPPER LEVEL SUPPORT FOR POST FRONTAL
SHOWER ACTIVITY...WHILE LOW LEVEL ONSHORE FLOW SHOULD PROVIDE
ADDITIONAL MOISTURE TO KEEP SHOWERS GOING THROUGH MUCH OF THE DAY.
BASED ON MODEL 850MB TEMPS AND 1000-500 MB THICKNESS VALUES...IT
APPEARS THAT THERE IS THE POTENTIAL FOR A RAIN/SNOW MIX TO AFFECT THE
INTERIOR LOWLANDS AT TIMES ON SAT. THE TEMP AND THICKNESS INDICATORS
ARE ONLY MARGINAL AND THERE IS SOME UNCERTAINTY AMONGST THE MODELS
JUST HOW COLD THE AIR MASS WILL BE...SO CONFIDENCE IS NOT ALL THAT
HIGH THAT THE INTERIOR LOWLANDS WILL SEE ANY SIGNIFICANT FLAKES. AT
ANY RATE...WITH THE MILD TEMPS WE HAVE SEEN OVER THE PAST FEW DAYS IT
IS UNLIKELY THAT ROAD SURFACES WILL BE ABLE TO COOL FAST ENOUGH FOR
THERE TO BE MAJOR TRAVEL CONCERNS. PYLE


LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY...MOST GUIDANCE
SUGGESTS THE UPPER TROUGH AXIS RESPONSIBLE FOR SATURDAYS SHOWERS WILL
BE MOVING ACROSS THE CASCADES SAT NIGHT...  WITH ANY LINGERING SHOWERS
COMING TO END OVERNIGHT. EXPECT SOME CLEARING SAT NIGHT AS COLD HIGH
PRESSURE BUILDS DOWN FROM BRITISH COLUMBIA...WITH LOW TEMPS LIKELY
GETTING WELL INTO THE 20S FOR MOST SPOTS. WITH HIGH PRESSURE
STRENGTHENING EAST OF THE CASCADES...EXPECT STRONG EAST WINDS TO RAMP
UP THROUGH THE GORGE SUNDAY MORNING AND PERSIST FOR MUCH OF THE
PERIOD THROUGH WEDNESDAY...WITH BREEZY CONDITIONS SPILLING INTO THE
PORTLAND/VANCOUVER METRO. MONDAY MAY BE A BRIEF BREAK FROM THE WINDS
AS A SYSTEM PASSES BY TO OUR NORTH.

MEANWHILE...A DISTURBANCE FROM THE ALEUTIANS IS EXPECTED TO CUT OFF
FROM THE MAIN PACIFIC JET AND SETTLE OFF THE CALIFORNIA COAST BY
SUNDAY...WHERE IT WILL LIKELY LINGER FOR A COUPLE DAYS. THERE IS A
CHANCE THIS SYSTEM COULD COME CLOSE ENOUGH TO SPREAD SOME PRECIP
NORTHWARD INTO OUR FORECAST AREA EARLY NEXT WEEK. IF THIS
OCCURS...THERE MAY BE SOME LIGHT FREEZING RAIN IN PORTIONS OF THE
WILLAMETTE VALLEY WITH SOME SNOW OR LIGHT FREEZING RAIN IN THE
GORGE. CUTOFF LOWS SUCH AS THIS ONE ARE NOTORIOUSLY DIFFICULT TO
FORECAST...AS MODELS STRUGGLE WITH THEM IN THE EXTENDED FORECAST
PERIOD. WHERE THIS UPPER LOW GOES WILL DICTATE THE WEATHER THROUGH
MIDWEEK...BUT TEMPS ARE EXPECTED TO SLOWLY MODERATE TUESDAY AND
WEDNESDAY.  WEAGLE

&&

.AVIATION...GENERALLY A MIX OF IFR TO VFR CONDITIONS ALONG THE
COAST...AND VFR OVER THE INTERIOR LOWLANDS. FRONTAL BOUNDARY
EXPECTED TO WEAKEN AND STALL OVER THE INTERIOR TODAY...WITH PLENTY
OF LOW-LEVEL MOISTURE. THUS...EXPECT MAINLY MVFR OR LOWER
CONDITIONS ACROSS THE AREA THROUGH TONIGHT. HIGHER TERRAIN...SUCH
AS THE OREGON COAST RANGE...SW WA WILLAPA HILLS AND THE CASCADES
WILL REMAIN OBSCURED THROUGHOUT THE PERIOD. EXPECT PRECIP
INTENSITY TO INCREASE OVERNIGHT INTO FRI MORNING.

KPDX AND APPROACHES...VFR CONDITIONS AS OF 16Z...BUT STILL EXPECT
MVFR TO BE THE PREDOMINANT CATEGORY AFTER 18Z. LITTLE CHANGE IN
OVERALL FLIGHT CATEGORY THIS AFTERNOON THROUGH TONIGHT. 12Z SALEM
UPPER AIR SOUNDING AND MODEL SOUNDINGS FOR KPDX INDICATED SE-S
WIND OF AROUND 10 KT AT THE SURFACE...BUT SW WIND 35-40 KT AT
FL020. THIS HAS PRODUCED LLWS NEAR THE AIR FIELD SO HAVE INCLUDED
IT IN THE TAF FOR THIS MORNING. WEISHAAR

&&

.MARINE...GALE FORCE WIND HAS DIMINISHED TO SMALL CRAFT ADVISORY
SPEEDS. MODELS SUGGEST GUSTS TO 25 KT AT TIMES MOST OF THE DAY.
THERE MAY BE SHORT PERIOD OF SUB-ADVISORY WIND SPEEDS THROUGH
TONIGHT...BUT WILL KEEP THE CURRENT SMALL CRAFT ADVISORY AS IS. A
MORE ROBUST COLD FRONT...WHICH HAS MUCH COLDER AIR BEHIND IT...WILL
MOVE SOUTH THROUGH THE COASTAL WATERS LATE FRI AND EARLY FRI EVENING
FOR CONTINUED SMALL CRAFT ADVISORY WINDS. THE WIND WILL SWITCH TO
THE NORTHWEST BEHIND THIS FRONT. THE NORTHWEST WINDS WILL EASE ON
SATURDAY...THEN OFFSHORE GAP ENHANCED EAST WINDS WILL DEVELOP
SATURDAY NIGHT AND SUNDAY...PROBABLY OF THE SMALL CRAFT ADVISORY
VARIETY. THESE OFFSHORE WINDS WILL CONTINUE INTO NEXT WEEK.

SEAS ARE UP TO 10 TO 13 FT THIS MORNING AND WILL REMAIN IN THAT
RANGE THROUGH TONIGHT. SEAS CONTINUE TO HOVER AROUND 10 FT INTO
SATURDAY...THEN FALL BELOW 10 FT BY SUNDAY. SEAS TODAY WILL BE
CHOPPY WITH AROUND 8 SECOND PERIODS FROM THE SOUTHWEST. PERIODS
WILL LENGTHEN TO AROUND 14 SECONDS LATER TODAY AND TONIGHT...THEN
SHIFT AND BE FROM THE NORTHWEST WITH PERIODS AND 10 OR 11 SECONDS
FRIDAY NIGHT INTO SATURDAY. WEISHAAR

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 8 AM PST SATURDAY FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT
     60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 8 AM PST SATURDAY
     FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR
     OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 PM PST FRIDAY
     FOR COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60
     NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 6 AM
     PST FRIDAY.

&&

$$

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 271744
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
944 AM PST THU NOV 27 2014

.SYNOPSIS...MOIST ONSHORE FLOW WILL GIVE PERIODS OF RAIN TO THE AREA
TODAY. A COLD FRONT WILL MOVE SOUTHEAST ACROSS THE AREA LATE TONIGHT
AND FRIDAY MORNING PRODUCING HEAVY RAIN OVER THE MOUNTAINS AND OVER
PARTS OF THE PUGET SOUND REGION. A CONVERGENCE ZONE WILL CONTINUE
OVER PUGET SOUND FRIDAY NIGHT...THEN ANOTHER COLD FRONT WILL MOVE
SOUTH THROUGH THE AREA LATE FRIDAY NIGHT INTO SATURDAY MORNING. SOME
SNOW OR RAIN AND SNOW MIXED IS LIKELY TO OCCUR WITH THE CONVERGENCE
ZONE AND ALONG THIS SECOND FRONT. COOL NORTHWEST FLOW ALOFT WILL
BRING MAINLY COOL AND DRY WEATHER SUNDAY THROUGH EARLY NEXT WEEK.

&&

.SHORT TERM...VERY ACTIVE AND CHANGEABLE WEATHER IS EXPECTED OVER
THE AREA THROUGH SATURDAY.

MOIST SW FLOW ALOFT AND ONSHORE FLOW WILL CONTINUE TODAY BRINGING
SOME LIGHT RAIN TO THE LOWLANDS AND HEAVY RAIN AT TIMES TO THE
MOUNTAINS. THE AIR MASS WILL REMAIN MOIST AND MILD WITH TEMPERATURES
IN THE 50S TODAY.

THE WARM FRONT FROM A COUPLE OF DAYS AGO IS STILL UP OVER B.C. AND
POISED TO MOVE BACK S OVER W WA AS A FAIRLY STRONG COLD FRONT
TONIGHT. RECENT MODELS ARE IN FAIRLY GOOD AGREEMENT WITH THE
TIMING...BRINGING THE FRONT TO A N COAST-BLI LINE AT 09Z/1 AM...TO A
HQM-SEA LINE 12Z-15Z/4AM-7AM...AND TO AN AST-CLS LINE AROUND 18Z/10
AM. HEAVY RAIN OVER THE MOUNTAINS WILL SHUT OFF BEHIND THE COLD
FRONT. SOME EARLIER MODELS SHOWED SOME RATHER HEAVY RAIN OVER OVER
THE GREATER PUGET SOUND REGION WITH THE FRONT...BUT THE NEWEST 12Z
RUNS HAVE TAKEN A STEP BACK. THE HIRES-ARW MODEL REMAINS THE
HEAVIEST PRECIP PRODUCER WITH AROUND AN INCH IN 3 HOURS WITH THE
FRONT. THE 12Z NAM12 AND HIRES-NMM MODELS ARE MUCH LIGHTER.
TEMPERATURES WILL REMAIN WARM ENOUGH TO KEEP THE PRECIP ALL RAIN.
TEMPERATURES WILL FALL INTO THE 30S TO LOWER 40S BY LATE FRIDAY
AFTERNOON.

BEHIND THE COLD FRONT A CONVERGENCE ZONE WILL FORM OVER CENTRAL
PUGET SOUND LATE FRIDAY AFTERNOON AND CONTINUE INTO FRIDAY NIGHT.
TEMPERATURES WILL FALL INTO THE LOWER TO MID 30S BY MID EVENING SO
THE CONVERGENCE ZONE MAY PRODUCE SOME SNOW FROM NORTH SEATTLE UP
THROUGH ARLINGTON. AT THE SAME TIME MODIFIED ARCTIC AIR WILL BEGIN
SPILLING OUT OF THE FRASER VALLEY. IT WILL BECOME VERY WINDY OVER
PARTS OF THE N INTERIOR FROM WHATCOM COUNTY ACROSS THE SAN JUAN
ISLANDS...BUT IT IS STILL UNCERTAIN WHETHER THE WINDS WILL END UP IN
THE WIND ADVISORY RANGE OR REACH HIGH WIND CRITERIA.

THE MOD-ARCTIC AIR WILL SPILL S ACROSS PUGET SOUND AS ANOTHER COLD
FRONT SATURDAY MORNING...AND SPILL WEST THROUGH THE STRAIT OF JUAN
DE FUCA. THERE IS POTENTIAL FOR A FEW INCHES OF SNOW OVER PUGET
SOUND SATURDAY MORNING AS THE FRONT MOVES S...AND OVER THE STRAIT AS
THE FLOW HITS THE NORTHERN OLYMPICS. THE SNOW WILL SHUT OFF IN THE
AFTERNOON AS THE AIR MASS DRIES OUT. KAM



.LONG TERM...PREVIOUS DISCUSSION FROM THE 330 AM AFD...AFTER A COLD
MORNING ON SUNDAY...EXPECT GRADUALLY MODERATING CONDITIONS LATER
SUNDAY THROUGH EARLY NEXT WEEK. MODELS VERY ON PRECIPITATION THREATS
STARTING MONDAY WITH THE GFS BRINGING SOUTHERN STREAM MOISTURE INTO
OREGON AND FAR SOUTHERN WASHINGTON AND THE ECMWF AND CANADIAN
SOLUTIONS BRINGING A NORTHERN STREAM TROUGH ACROSS THE AREA DURING
THE SAME PERIOD. AT THIS TIME THE DRY FORECAST WAS MAINTAINED BUT
CLOUDS WERE INCREASED. ALBRECHT

&&

.HYDROLOGY...THERE WAS A LULL IN HEAVY RAIN OVER THE CENTRAL
CASCADES LAST NIGHT WHICH ALLOWED THE SNOQUALMIE AND PUYALLUP RIVERS
TO FALL BELOW FLOOD STAGE. FLOOD WARNINGS ON THOSE RIVERS HAVE ENDED
FOR THE TIME BEING.

IN CONTRAST...HEAVY RAIN FELL LAST NIGHT OVER THE SOUTHWEST FACING
SLOPES OF THE OLYMPICS AND THE CASCADES FROM ABOUT THE STILLAGUAMISH
BASIN NORTHWARD. 12-HOUR AMOUNTS RANGE FROM ABOUT ONE INCH IN THE
SOUTH TO TWO INCHES IN THE NORTH. THE SKOKOMISH RIVER IS NOW ABOVE
FLOOD STAGE AND THE WARNING IS OUT. THE NORTH CASCADE RIVERS HAVE
STARTED RISING AGAIN WITH FLOODING ON AT LEAST SOME OF THEM LOOKING
LIKELY THIS EVENING OR TONIGHT.

SIGNIFICANT PRECIPITATION WILL CONTINUE THROUGH FRIDAY...WITH STRONG
OROGRAPHIC FORCING AS SOUTHWESTERLY LOW LEVEL WINDS OF 40 KT OR SO
CONTINUE. THE HEAVIEST PRECIPITATION WILL BE OVER THE OLYMPICS AND
NORTH CASCADES TODAY AND MOST OF TONIGHT...AND THEN THE FRONTAL BAND
AND HEAVIEST RAIN WILL GRADUALLY SHIFT SOUTHWARD ON FRIDAY. THE SNOW
LEVEL WILL BE 5500 TO 7000 FT THROUGH TONIGHT...AND IT SHOULD FALL
GRADUALLY ON FRIDAY AS THE COLD FRONT STARTS TO MOVE SOUTHEAST
THROUGH THE AREA.

IN THE NORTH CASCADES...THE NOOKSACK AND SKAGIT RIVERS CAME CLOSE TO
FLOODING ON WEDNESDAY...AND BOTH FACE A THREAT OF FLOODING IN THIS
EPISODE. IN ADDITION THE STILLAGUAMISH...SKYKOMISH...TOLT...
SNOQUALMIE...AND SNOHOMISH RIVERS -- ALL OF WHICH FLOODED OR NEARLY
FLOODED IN THE PAST COUPLE DAYS -- COULD FLOOD AS WELL. FLOODING ON
THESE CASCADE RIVERS WOULD PROBABLY BEGIN TONIGHT OR FRIDAY. A MAJOR
FLOODING EPISODE IS UNLIKELY...BUT IT WOULD BE NO SURPRISE IF MANY
OF THESE RIVERS HAVE MINOR TO MODERATE FLOODING.

THE CASCADES SOUTH OF THE SNOHOMISH BASIN WILL PROBABLY RECEIVE 2 TO
4 INCHES OF RAIN. MOST OF THAT COULD FALL ON FRIDAY AND SOME MODELS
-- ESPECIALLY THE UW WRF-GFS -- SHOW FAIRLY INTENSE RAINFALL IN THAT
AREA. SO THE RIVERS THERE FACE A THREAT OF FLOODING AS WELL. OF
COURSE SOME OF THEM RECENTLY FLOODED...AND THEY ARE ALL RUNNING
HIGH. A FLOOD WATCH REMAINS IN EFFECT.

THE COLD FRONT WILL MOVE SOUTHEAST OF WESTERN WASHINGTON FRIDAY
NIGHT...WITH COLD AND DRIER WEATHER LIKELY THIS WEEKEND. RIVERS WILL
RECEDE AND THE FLOOD THREAT WILL END FOR THE FORESEEABLE FUTURE.
MCDONNAL/BURKE

&&

.AVIATION...DELAYED....EXPECT RAIN AT TIMES THIS MORNING AS A COLD
FRONT PUSHES THROUGH WESTERN WA. THE FLOW ALOFT IS WESTERLY. MVFR
CIGS ARE POSSIBLE THIS MORNING IN -RA. GUSTY SOUTH WINDS ARE ALSO
EXPECTED WITH THIS FRONT. MOIST WESTERLY FLOW WILL CONTINUE THIS
AFTERNOON WITH SHOWERS MAINLY AFFECTING THE COAST AND MOUNTAINS.
RAIN WILL CONTINUE TONIGHT AS ANOTHER COLD FRONT SHIFTS S/SE INTO
WESTERN WA. 33

KSEA...EXPECT LIGHT RAIN AT TIMES TODAY WITH CIGS NEAR 3000 FT.
GUSTY SOUTH WINDS 20015G25KT EXPECTED AT THE TERMINAL THROUGHOUT THE
DAY. 33

&&

.MARINE...SMALL CRAFT ADVISORIES ARE IN EFFECT FOR ALL ZONES WITH
HIGHER PRESSURE IN THE SOUTH AND LOWER PRESSURE IN THE NORTH
PRODUCING HIGH END SMALL CRAFT ADVISORY LEVEL WINDS. PRESSURE
GRADIENTS WILL REMAIN TIGHT TONIGHT THROUGH FRI MORNING AS A WELL
DEVELOPED COLD FRONT SHIFTS SOUTH INTO WESTERN WA. WINDS WILL SWITCH
FROM THE SW TO THE N OR NW AS THE FRONT MOVES THROUGH.

STRONG HIGH PRES OVER INTERIOR B.C. WILL BRING N/NE FRASER RIVER
OUTFLOW WINDS LATE FRI NIGHT INTO SAT WITH GALES LIKELY OVER THE
NORTHERN INLAND WATERS. OFFSHORE FLOW WILL PREVAIL SUN AND MON WITH
HIGH PRES EAST OF THE CASCADES. JSMITH

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...FLOOD WATCHES AND WARNINGS IN EFFECT FOR PORTIONS OF
      WESTERN WASHINGTON.
PZ...SMALL CRAFT ADVISORY ALL WATERS.
     SMALL CRAFT ADVISORY GRAYS HARBOR BAR FOR ROUGH 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 271244
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
443 AM PST THU NOV 27 2014

.SYNOPSIS...
Mild and breezy weather is expected Thanksgiving with areas of
fog in the morning. Snow levels should rise above the mountain
passes. Motorists with plans to travel over the mountain passes
should experience good conditions today through Friday afternoon.
The arrival of a very cold and windy arctic front Friday Night
into Saturday will bring winter driving conditions to the mountain
passes and much cooler weather for the weekend.

&&

.DISCUSSION...

Today through Fri: The biggest changes to the fcst were to
decrease the amnt of pcpn for all non-mountain zones, increase the
winds, and warm temperatures a bit. Though by far the most
eventful part of the fcst will be Fri Nt through the weekend as
we deal with a significant cold front passage that will produce
snow for all elevations, gusty cold north winds and temps as low
as the single digits, we have some relatively mild, but windy
weather to deal with first. Currently behind a cool frontal
passage late yesterday, we`re still anticipating sfc winds to
increase slowly and help to mix out any dense fog now in the Upper
Columbia Basin. We`ve extended the dense fog advsy a few more
hours and will be watched carefully. The good news is that temps
are above freezing, so very slick roads shouldn`t be a big problem
on this important Thanksgiving day travel morning. Today and
Friday all of Ern Wa and N Id will be in a mild pre-arctic cold
front air mass, with well- above normal temps. However, this same
pattern typically favors very gusty winds. This time it`s no
different. Most model guidance shows persistent 850mb winds
(roughly 5k ft above the sfc) from the southwest at 35-45kt.
Expect these winds to begin to increase this morning. Temps will
be mild, even low temps for areas that manage to remain coupled
with these winds aloft (non- valley sites). bz

Friday night through Sunday...The wet but mild weather pattern
will come to an end as an arctic front slides south across the
region bringing much colder and drier air with it. A strong
surface low will slide south across eastern WA and north ID Friday
night, bringing a good chance of precipitation to the eastern half
of the forecast area along with strong gusty southwest winds. Snow
levels will start out around 5k ft Friday evening then come
crashing down overnight. The bulk of the precip will fall as rain
in the valleys. By the time the cold air moves in, the low will be
over central Idaho with showers limited to the southeast zones.
The Camas Prairie may see some low end advisory snowfall but even
this amount is uncertain.

On Saturday the exiting low and building high pressure over
southern BC will set up a strong surface pressure gradient that
will channel northerly winds down the Okanogan Valley and Purcell
Trench and into the basin. This pattern shows the potential for
wind highlights and will continue to be monitored. Saturday
morning temperatures will likely be the high for the day as the
frigid air continues to march south across the area. The rest of
the weekend will continue the cold and dry trend with lows in the
single digits across the northern zones. Valley highs in the 20s
will be common.

Sunday night through Wednesday...The cold temperatures will start
to moderate as northerly winds are replaced by more westerly flow.
Model solutions diverge when it comes to moisture over the region.
The GFS wants to bring the surface boundary back north as a warm
front but the new run of the ECMWF brings a shortwave trough
across the northeast zones. No big changes made to the extended
forecast at this point other than to trend PoPs toward climo for
the end of the forecast period. /Kelch

&&

.AVIATION...
12Z TAFS: We`ve made significant changes to the wind fcst for the
Spokane/ C`Da and Pullman TAFs... increasing the winds speeds
significantly especially for KGEG. 12z OTX raob and VWP showed
40-50kts 1500-2500ft of the sfc contributing significantly to the
rapid mixing at KGEG and simultaneous gusts to 25 kts. These winds
should peak this morning, but only decrease slightly during the
day. For sites that have not mixed, LLWS has been added for the
next few hours. As far as the IFR/LIFR ceilings and/or vsby at
KMWH and KEAT... these are expected to become VFR by mid morning.

NOTE: The VIS sensor at EAT is out of service so amendments to
VIS are not scheduled. bz

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        55  41  50  27  27  12 /  30  20  70  60  10   0
Coeur d`Alene  54  41  49  29  29  12 /  40  40  80  90  20  10
Pullman        55  43  53  32  32  16 /  30  30  90  90  50  10
Lewiston       57  46  56  38  38  23 /  20  20  60  70  60  20
Colville       51  40  47  22  22   7 /  50  40  70  60  10   0
Sandpoint      48  38  45  26  26   8 /  70  70  80  90  20  10
Kellogg        48  39  45  30  30  12 /  80  70  90 100  50  10
Moses Lake     56  41  56  27  27  12 /  10  20  30  30  10   0
Wenatchee      51  41  51  29  29  13 /  10  30  20  20  10   0
Omak           47  37  46  16  16   3 /  20  20  30  20  10   0

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...Dense Fog Advisory until 7 AM PST this morning for Moses Lake
     Area-Upper Columbia Basin-Waterville Plateau.

&&

$$





000
FXUS66 KOTX 271244
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
443 AM PST THU NOV 27 2014

.SYNOPSIS...
Mild and breezy weather is expected Thanksgiving with areas of
fog in the morning. Snow levels should rise above the mountain
passes. Motorists with plans to travel over the mountain passes
should experience good conditions today through Friday afternoon.
The arrival of a very cold and windy arctic front Friday Night
into Saturday will bring winter driving conditions to the mountain
passes and much cooler weather for the weekend.

&&

.DISCUSSION...

Today through Fri: The biggest changes to the fcst were to
decrease the amnt of pcpn for all non-mountain zones, increase the
winds, and warm temperatures a bit. Though by far the most
eventful part of the fcst will be Fri Nt through the weekend as
we deal with a significant cold front passage that will produce
snow for all elevations, gusty cold north winds and temps as low
as the single digits, we have some relatively mild, but windy
weather to deal with first. Currently behind a cool frontal
passage late yesterday, we`re still anticipating sfc winds to
increase slowly and help to mix out any dense fog now in the Upper
Columbia Basin. We`ve extended the dense fog advsy a few more
hours and will be watched carefully. The good news is that temps
are above freezing, so very slick roads shouldn`t be a big problem
on this important Thanksgiving day travel morning. Today and
Friday all of Ern Wa and N Id will be in a mild pre-arctic cold
front air mass, with well- above normal temps. However, this same
pattern typically favors very gusty winds. This time it`s no
different. Most model guidance shows persistent 850mb winds
(roughly 5k ft above the sfc) from the southwest at 35-45kt.
Expect these winds to begin to increase this morning. Temps will
be mild, even low temps for areas that manage to remain coupled
with these winds aloft (non- valley sites). bz

Friday night through Sunday...The wet but mild weather pattern
will come to an end as an arctic front slides south across the
region bringing much colder and drier air with it. A strong
surface low will slide south across eastern WA and north ID Friday
night, bringing a good chance of precipitation to the eastern half
of the forecast area along with strong gusty southwest winds. Snow
levels will start out around 5k ft Friday evening then come
crashing down overnight. The bulk of the precip will fall as rain
in the valleys. By the time the cold air moves in, the low will be
over central Idaho with showers limited to the southeast zones.
The Camas Prairie may see some low end advisory snowfall but even
this amount is uncertain.

On Saturday the exiting low and building high pressure over
southern BC will set up a strong surface pressure gradient that
will channel northerly winds down the Okanogan Valley and Purcell
Trench and into the basin. This pattern shows the potential for
wind highlights and will continue to be monitored. Saturday
morning temperatures will likely be the high for the day as the
frigid air continues to march south across the area. The rest of
the weekend will continue the cold and dry trend with lows in the
single digits across the northern zones. Valley highs in the 20s
will be common.

Sunday night through Wednesday...The cold temperatures will start
to moderate as northerly winds are replaced by more westerly flow.
Model solutions diverge when it comes to moisture over the region.
The GFS wants to bring the surface boundary back north as a warm
front but the new run of the ECMWF brings a shortwave trough
across the northeast zones. No big changes made to the extended
forecast at this point other than to trend PoPs toward climo for
the end of the forecast period. /Kelch

&&

.AVIATION...
12Z TAFS: We`ve made significant changes to the wind fcst for the
Spokane/ C`Da and Pullman TAFs... increasing the winds speeds
significantly especially for KGEG. 12z OTX raob and VWP showed
40-50kts 1500-2500ft of the sfc contributing significantly to the
rapid mixing at KGEG and simultaneous gusts to 25 kts. These winds
should peak this morning, but only decrease slightly during the
day. For sites that have not mixed, LLWS has been added for the
next few hours. As far as the IFR/LIFR ceilings and/or vsby at
KMWH and KEAT... these are expected to become VFR by mid morning.

NOTE: The VIS sensor at EAT is out of service so amendments to
VIS are not scheduled. bz

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        55  41  50  27  27  12 /  30  20  70  60  10   0
Coeur d`Alene  54  41  49  29  29  12 /  40  40  80  90  20  10
Pullman        55  43  53  32  32  16 /  30  30  90  90  50  10
Lewiston       57  46  56  38  38  23 /  20  20  60  70  60  20
Colville       51  40  47  22  22   7 /  50  40  70  60  10   0
Sandpoint      48  38  45  26  26   8 /  70  70  80  90  20  10
Kellogg        48  39  45  30  30  12 /  80  70  90 100  50  10
Moses Lake     56  41  56  27  27  12 /  10  20  30  30  10   0
Wenatchee      51  41  51  29  29  13 /  10  30  20  20  10   0
Omak           47  37  46  16  16   3 /  20  20  30  20  10   0

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...Dense Fog Advisory until 7 AM PST this morning for Moses Lake
     Area-Upper Columbia Basin-Waterville Plateau.

&&

$$





000
FXUS66 KOTX 271244
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
443 AM PST THU NOV 27 2014

.SYNOPSIS...
Mild and breezy weather is expected Thanksgiving with areas of
fog in the morning. Snow levels should rise above the mountain
passes. Motorists with plans to travel over the mountain passes
should experience good conditions today through Friday afternoon.
The arrival of a very cold and windy arctic front Friday Night
into Saturday will bring winter driving conditions to the mountain
passes and much cooler weather for the weekend.

&&

.DISCUSSION...

Today through Fri: The biggest changes to the fcst were to
decrease the amnt of pcpn for all non-mountain zones, increase the
winds, and warm temperatures a bit. Though by far the most
eventful part of the fcst will be Fri Nt through the weekend as
we deal with a significant cold front passage that will produce
snow for all elevations, gusty cold north winds and temps as low
as the single digits, we have some relatively mild, but windy
weather to deal with first. Currently behind a cool frontal
passage late yesterday, we`re still anticipating sfc winds to
increase slowly and help to mix out any dense fog now in the Upper
Columbia Basin. We`ve extended the dense fog advsy a few more
hours and will be watched carefully. The good news is that temps
are above freezing, so very slick roads shouldn`t be a big problem
on this important Thanksgiving day travel morning. Today and
Friday all of Ern Wa and N Id will be in a mild pre-arctic cold
front air mass, with well- above normal temps. However, this same
pattern typically favors very gusty winds. This time it`s no
different. Most model guidance shows persistent 850mb winds
(roughly 5k ft above the sfc) from the southwest at 35-45kt.
Expect these winds to begin to increase this morning. Temps will
be mild, even low temps for areas that manage to remain coupled
with these winds aloft (non- valley sites). bz

Friday night through Sunday...The wet but mild weather pattern
will come to an end as an arctic front slides south across the
region bringing much colder and drier air with it. A strong
surface low will slide south across eastern WA and north ID Friday
night, bringing a good chance of precipitation to the eastern half
of the forecast area along with strong gusty southwest winds. Snow
levels will start out around 5k ft Friday evening then come
crashing down overnight. The bulk of the precip will fall as rain
in the valleys. By the time the cold air moves in, the low will be
over central Idaho with showers limited to the southeast zones.
The Camas Prairie may see some low end advisory snowfall but even
this amount is uncertain.

On Saturday the exiting low and building high pressure over
southern BC will set up a strong surface pressure gradient that
will channel northerly winds down the Okanogan Valley and Purcell
Trench and into the basin. This pattern shows the potential for
wind highlights and will continue to be monitored. Saturday
morning temperatures will likely be the high for the day as the
frigid air continues to march south across the area. The rest of
the weekend will continue the cold and dry trend with lows in the
single digits across the northern zones. Valley highs in the 20s
will be common.

Sunday night through Wednesday...The cold temperatures will start
to moderate as northerly winds are replaced by more westerly flow.
Model solutions diverge when it comes to moisture over the region.
The GFS wants to bring the surface boundary back north as a warm
front but the new run of the ECMWF brings a shortwave trough
across the northeast zones. No big changes made to the extended
forecast at this point other than to trend PoPs toward climo for
the end of the forecast period. /Kelch

&&

.AVIATION...
12Z TAFS: We`ve made significant changes to the wind fcst for the
Spokane/ C`Da and Pullman TAFs... increasing the winds speeds
significantly especially for KGEG. 12z OTX raob and VWP showed
40-50kts 1500-2500ft of the sfc contributing significantly to the
rapid mixing at KGEG and simultaneous gusts to 25 kts. These winds
should peak this morning, but only decrease slightly during the
day. For sites that have not mixed, LLWS has been added for the
next few hours. As far as the IFR/LIFR ceilings and/or vsby at
KMWH and KEAT... these are expected to become VFR by mid morning.

NOTE: The VIS sensor at EAT is out of service so amendments to
VIS are not scheduled. bz

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        55  41  50  27  27  12 /  30  20  70  60  10   0
Coeur d`Alene  54  41  49  29  29  12 /  40  40  80  90  20  10
Pullman        55  43  53  32  32  16 /  30  30  90  90  50  10
Lewiston       57  46  56  38  38  23 /  20  20  60  70  60  20
Colville       51  40  47  22  22   7 /  50  40  70  60  10   0
Sandpoint      48  38  45  26  26   8 /  70  70  80  90  20  10
Kellogg        48  39  45  30  30  12 /  80  70  90 100  50  10
Moses Lake     56  41  56  27  27  12 /  10  20  30  30  10   0
Wenatchee      51  41  51  29  29  13 /  10  30  20  20  10   0
Omak           47  37  46  16  16   3 /  20  20  30  20  10   0

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...Dense Fog Advisory until 7 AM PST this morning for Moses Lake
     Area-Upper Columbia Basin-Waterville Plateau.

&&

$$





000
FXUS66 KOTX 271244
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
443 AM PST THU NOV 27 2014

.SYNOPSIS...
Mild and breezy weather is expected Thanksgiving with areas of
fog in the morning. Snow levels should rise above the mountain
passes. Motorists with plans to travel over the mountain passes
should experience good conditions today through Friday afternoon.
The arrival of a very cold and windy arctic front Friday Night
into Saturday will bring winter driving conditions to the mountain
passes and much cooler weather for the weekend.

&&

.DISCUSSION...

Today through Fri: The biggest changes to the fcst were to
decrease the amnt of pcpn for all non-mountain zones, increase the
winds, and warm temperatures a bit. Though by far the most
eventful part of the fcst will be Fri Nt through the weekend as
we deal with a significant cold front passage that will produce
snow for all elevations, gusty cold north winds and temps as low
as the single digits, we have some relatively mild, but windy
weather to deal with first. Currently behind a cool frontal
passage late yesterday, we`re still anticipating sfc winds to
increase slowly and help to mix out any dense fog now in the Upper
Columbia Basin. We`ve extended the dense fog advsy a few more
hours and will be watched carefully. The good news is that temps
are above freezing, so very slick roads shouldn`t be a big problem
on this important Thanksgiving day travel morning. Today and
Friday all of Ern Wa and N Id will be in a mild pre-arctic cold
front air mass, with well- above normal temps. However, this same
pattern typically favors very gusty winds. This time it`s no
different. Most model guidance shows persistent 850mb winds
(roughly 5k ft above the sfc) from the southwest at 35-45kt.
Expect these winds to begin to increase this morning. Temps will
be mild, even low temps for areas that manage to remain coupled
with these winds aloft (non- valley sites). bz

Friday night through Sunday...The wet but mild weather pattern
will come to an end as an arctic front slides south across the
region bringing much colder and drier air with it. A strong
surface low will slide south across eastern WA and north ID Friday
night, bringing a good chance of precipitation to the eastern half
of the forecast area along with strong gusty southwest winds. Snow
levels will start out around 5k ft Friday evening then come
crashing down overnight. The bulk of the precip will fall as rain
in the valleys. By the time the cold air moves in, the low will be
over central Idaho with showers limited to the southeast zones.
The Camas Prairie may see some low end advisory snowfall but even
this amount is uncertain.

On Saturday the exiting low and building high pressure over
southern BC will set up a strong surface pressure gradient that
will channel northerly winds down the Okanogan Valley and Purcell
Trench and into the basin. This pattern shows the potential for
wind highlights and will continue to be monitored. Saturday
morning temperatures will likely be the high for the day as the
frigid air continues to march south across the area. The rest of
the weekend will continue the cold and dry trend with lows in the
single digits across the northern zones. Valley highs in the 20s
will be common.

Sunday night through Wednesday...The cold temperatures will start
to moderate as northerly winds are replaced by more westerly flow.
Model solutions diverge when it comes to moisture over the region.
The GFS wants to bring the surface boundary back north as a warm
front but the new run of the ECMWF brings a shortwave trough
across the northeast zones. No big changes made to the extended
forecast at this point other than to trend PoPs toward climo for
the end of the forecast period. /Kelch

&&

.AVIATION...
12Z TAFS: We`ve made significant changes to the wind fcst for the
Spokane/ C`Da and Pullman TAFs... increasing the winds speeds
significantly especially for KGEG. 12z OTX raob and VWP showed
40-50kts 1500-2500ft of the sfc contributing significantly to the
rapid mixing at KGEG and simultaneous gusts to 25 kts. These winds
should peak this morning, but only decrease slightly during the
day. For sites that have not mixed, LLWS has been added for the
next few hours. As far as the IFR/LIFR ceilings and/or vsby at
KMWH and KEAT... these are expected to become VFR by mid morning.

NOTE: The VIS sensor at EAT is out of service so amendments to
VIS are not scheduled. bz

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        55  41  50  27  27  12 /  30  20  70  60  10   0
Coeur d`Alene  54  41  49  29  29  12 /  40  40  80  90  20  10
Pullman        55  43  53  32  32  16 /  30  30  90  90  50  10
Lewiston       57  46  56  38  38  23 /  20  20  60  70  60  20
Colville       51  40  47  22  22   7 /  50  40  70  60  10   0
Sandpoint      48  38  45  26  26   8 /  70  70  80  90  20  10
Kellogg        48  39  45  30  30  12 /  80  70  90 100  50  10
Moses Lake     56  41  56  27  27  12 /  10  20  30  30  10   0
Wenatchee      51  41  51  29  29  13 /  10  30  20  20  10   0
Omak           47  37  46  16  16   3 /  20  20  30  20  10   0

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...Dense Fog Advisory until 7 AM PST this morning for Moses Lake
     Area-Upper Columbia Basin-Waterville Plateau.

&&

$$





000
FXUS66 KPQR 271128
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
327 AM PST THU NOV 27 2014

.SYNOPSIS...A WEAK COLD FRONT WILL PUSH SLOWLY INLAND TODAY. THE
FRONT WILL THEN STALL OVER SOUTH-CENTRAL OREGON TONIGHT AND FRI. THIS
FRONT WILL BEGIN TO LIFT NORTHWARD AGAIN EARLY FRI. ANOTHER STRONGER
COLD FRONT WILL MOVE S THROUGH THE REGION LATE FRI INTO SAT. THIS
FRONT WILL USHER IN MUCH COLDER WEATHER. SNOW LEVELS WILL FALL
RAPIDLY SAT...WITH A RAIN/SNOW MIX A POSSIBILITY FOR THE INTERIOR
LOWLANDS. HIGH PRES OVER THE INTERIOR NW WILL TURN THE FLOW OFFSHORE
BY SUN FOR DRY AND COLD WEATHER. ANOTHER SYSTEM COMING UP FROM THE S
SOMETIME EARLY NEXT WEEK WILL ATTEMPT TO SPREAD SOME PRECIPITATION UP
OVER THE COLD AIR MASS LEFT OVER FROM THE WEEKEND.
&&

SHORT TERM...TODAY THROUGH SATURDAY...
BREEZY SOUTHERLY WINDS AHEAD OF AN APPROACHING COLD FRONT ARE KEEPING
EXCEPTIONALLY MILD CONDITIONS IN PLACE ACROSS SOUTHWEST OREGON AND
NORTHWEST OREGON THIS MORNING. IN FACT...THE TEMPS IN THE UPPER 50S TO
LOW 60S BEING OBSERVED ACROSS MUCH OF THE REGION AT CURRENT ARE VERY
CLOSE TO THE RECORD DAILY HIGH TEMPS FOR THE LAST WEEK OF NOVEMBER.
HOWEVER...THE PERIOD OF MILD WEATHER THAT WE HAVE BEEN EXPERIENCING
OVER THE PAST FEW DAYS WILL BE COMING TO AN END VERY SHORTLY.

THE COLD FRONT APPROACHING THE COAST THIS MORNING IS NOT TERRIBLY
IMPRESSIVE. LOOKING AT THE LATEST IR SATELLITE IMAGERY...IT IS
APPARENT THAT THE UPPER LEVEL FRONT AND ASSOCIATED MOISTURE HAS MOVED
OUT AHEAD OF THE SURFACE FRONTAL BOUNDARY. THE SURFACE FRONT CAN BE
MADE OUT ON SATELLITE JUST OFFSHORE AROUND BUOY 29. WITH ONLY SHALLOW
MOISTURE REMAINING AND LITTLE IN THE WAY OF FORCING ALOFT...THE
ASSOCIATED PRECIPITATION THAT IS MOVING ONSHORE IS DEFINITELY ON THE
PATCHIER SIDE. THE RAIN HAS BECOME A BIT STEADIER OVER THE PAST FEW
HOURS ALONG THE N COAST AND COAST RANGE...BUT MOST SITES ARE ONLY
PICKING UP A FEW HUNDREDTHS OF AN INCH OF RAIN PER HOUR.
STILL...EXPECT MOST LOCATIONS WILL SEE A DECENT STEADY RAIN AS THE
FRONT PUSHES ONSHORE THIS MORNING AND THEN MOVES INLAND THROUGH THE
DAY. THE FRONT WILL EVENTUALLY STALL OVER SOUTHERN AND CENTRAL OREGON
LATER THIS AFTERNOON AND THIS EVENING.

THE OTHER FEATURE OF INTEREST THAT WE ARE WATCHING THIS MORNING IS A
PERSISTENT STATIONARY BAROCLINIC ZONE THAT IS CURRENTLY DRAPED OVER
BRITISH COLUMBIA AND FAR NORTHERN WASHINGTON. AN UPPER LEVEL TROUGH
WILL DRIVE THIS BOUNDARY SOUTHWARD FRI AND FRI NIGHT AS A SHARP COLD
FRONT. AT THE SAME TIME...THE STALLED FRONT OVER CENTRAL OREGON IS
FCST TO PUSH NORTHWARD AGAIN FRI MORNING. BETWEEN THESE TWO FRONTAL
BOUNDARIES...EXPECT RAINFALL TO STEADILY INCREASE AS THE DAY
PROGRESSES FRI. AS THE SHARP COLD FRONT FROM THE NORTH DIVES THROUGH
THE REGION LATER FRI AND FRI NIGHT...A MUCH COLDER AIR MASS ALOFT
WILL MOVE INTO THE REGION.

THE PARENT UPPER LEVEL TROUGH WILL SWING INTO THE REGION FROM THE
NORTH ON SAT TO PROVIDE SOME UPPER LEVEL SUPPORT FOR POST FRONTAL
SHOWER ACTIVITY...WHILE LOW LEVEL ONSHORE FLOW SHOULD PROVIDE
ADDITIONAL MOISTURE TO KEEP SHOWERS GOING THROUGH MUCH OF THE DAY.
BASED ON MODEL 850MB TEMPS AND 1000-500 MB THICKNESS VALUES...IT
APPEARS THAT THERE IS THE POTENTIAL FOR A RAIN/SNOW MIX TO AFFECT THE
INTERIOR LOWLANDS AT TIMES ON SAT. THE TEMP AND THICKNESS INDICATORS
ARE ONLY MARGINAL AND THERE IS SOME UNCERTAINTY AMONGST THE MODELS
JUST HOW COLD THE AIR MASS WILL BE...SO CONFIDENCE IS NOT ALL THAT
HIGH THAT THE INTERIOR LOWLANDS WILL SEE ANY SIGNIFICANT FLAKES. AT
ANY RATE...WITH THE MILD TEMPS WE HAVE SEEN OVER THE PAST FEW DAYS IT
IS UNLIKELY THAT ROAD SURFACES WILL BE ABLE TO COOL FAST ENOUGH FOR
THERE TO BE MAJOR TRAVEL CONCERNS. PYLE


LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY...MOST GUIDANCE
SUGGESTS THE UPPER TROUGH AXIS RESPONSIBLE FOR SATURDAYS SHOWERS WILL
BE MOVING ACROSS THE CASCADES SAT NIGHT...  ITH ANY LINGERING SHOWERS
COMING TO END OVERNIGHT. EXPECT SOME CLEARING SAT NIGHT AS COLD HIGH
PRESSURE BUILDS DOWN FROM BRITISH COLUMBIA...WITH LOW TEMPS LIKELY
GETTING WELL INTO THE 20S FOR MOST SPOTS. WITH HIGH PRESSURE
STRENGTHENING EAST OF THE CASCADES...EXPECT STRONG EAST WINDS TO RAMP
UP THROUGH THE GORGE SUNDAY MORNING AND PERSIST FOR MUCH OF THE
PERIOD THROUGH WEDNESDAY...WITH BREEZY CONDITIONS SPILLING INTO THE
PORTLAND/VANCOUVER METRO. MONDAY MAY BE A BRIEF BREAK FROM THE WINDS
AS A SYSTEM PASSES BY TO OUR NORTH.

MEANWHILE...A DISTURBANCE FROM THE ALEUTIANS IS EXPECTED TO CUT OFF
FROM THE MAIN PACIFIC JET AND SETTLE OFF THE CALIFORNIA COAST BY
SUNDAY...WHERE IT WILL LIKELY LINGER FOR A COUPLE DAYS. THERE IS A
CHANCE THIS SYSTEM COULD COME CLOSE ENOUGH TO SPREAD SOME PRECIP
NORTHWARD INTO OUR FORECAST AREA EARLY NEXT WEEK. IF THIS
OCCURS...THERE MAY BE SOME LIGHT FREEZING RAIN IN PORTIONS OF THE
WILLAMETTE VALLEY WITH SOME SNOW OR LIGHT FREEZING RAIN IN THE
GORGE. CUTOFF LOWS SUCH AS THIS ONE ARE NOTORIOUSLY DIFFICULT TO
FORECAST...AS MODELS STRUGGLE WITH THEM IN THE EXTENDED FORECAST
PERIOD. WHERE THIS UPPER LOW GOES WILL DICTATE THE WEATHER THROUGH
MIDWEEK...BUT TEMPS ARE EXPECTED TO SLOWLY MODERATE TUESDAY AND
WEDNESDAY.  WEAGLE
&&

.AVIATION...A MIXTURE OF IFR AND LOW MVFR CONDITIONS HAVE SPREAD
ONTO THE COAST WITH THE FIRST INCOMING COLD FRONT EARLY THIS
MORNING. CONDITIONS AT THE COAST WILL THEN CONTINUE IN THAT RANGE
INTO FRIDAY AS THE FRONT MOVES ONSHORE BUT STALLS AND SOME
PRECIPITATION CONTINUES AT TIMES. INLAND CONDITIONS ARE STILL VFR
EARLY THIS MORNING BUT WILL PROBABLY SEE SOME MVFR CONDITIONS AS
THE FRONT MOVES THROUGH TODAY. THE FRONT STALLS AND WEAKENS OVER
THE INLAND AREAS THIS AFTERNOON AND TONIGHT BEFORE THE NEXT FRONT
APPROACHES FROM THE NORTH ON FRIDAY. MODEL GUIDANCE SUGGESTS MVFR
CIGS OR LOW END VFR CIGS WILL CONTINUE OVER THE AREA BEHIND THE
FRONT INTO FRIDAY.

KPDX AND APPROACHES...VFR CONDITIONS EARLY THIS MORNING BUT EXPECT
PERIODIC MVFR CIGS TO DEVELOP THE REMAINDER OF THE MORNING. DO NOT
EXPECT MUCH CHANGE THE REMAINDER OF TODAY AND TONIGHT AS CIGS
HOVER BETWEEN MVFR AND LOW END VFR WITH SOME LIGHT PRECIPITATION
AT TIMES. PT
&&

.MARINE...WINDS HAVE PICKED UP AS THE FRONT MOVED FARTHER INTO THE
COASTAL WATERS OVERNIGHT...AND GALE WARNING LOOKS GOOD. BELIEVE
WINDS IN THE CENTRAL OREGON WATERS WILL EXTEND AN HOUR OR TWO
PAST 4 AM SO HAVE EXTENDED THE GALE THERE. THE FIRST COLD FRONT
MOVES ONSHORE THIS MORNING WHICH WILL ALLOW THE WINDS TO EAST A
BIT...BUT THERE IS REALLY NOT MUCH COLD AIR BEHIND THIS FRONT.
THEN IT LOOKS LIKE SMALL CRAFT ADVISORY WINDS FROM THE SOUTHWEST
FOR THE REMAINDER OF TODAY...TONIGHT...INTO FRIDAY. A SECONDARY
COLD FRONT WHICH HAS MUCH COLDER AIR BEHIND IT WILL MOVE SOUTH
THROUGH THE COASTAL WATERS FRIDAY AND EARLY FRIDAY EVENING FOR
CONTINUED SMALL CRAFT ADVISORY WINDS...WITH WIND DIRECTIONS
SWITCHING TO THE NORTHWEST BEHIND THIS FRONT. THE NORTHWEST WINDS
WILL EASE ON SATURDAY...THEN OFFSHORE GAP ENHANCED EAST WINDS WILL
DEVELOP SATURDAY NIGHT AND SUNDAY...PROBABLY OF THE SMALL CRAFT
ADVISORY VARIETY. THESE OFFSHORE WINDS WILL CONTINUE INTO NEXT
WEEK.

SEAS ARE RUNNING AROUND 10 FEET RIGHT NOW BUT ARE EXPECTED TO RUN
IN THE 10 TO 13 FT RANGE TODAY INTO FRIDAY...THEN CONTINUE TO
HOVER AROUND 10 FT INTO SATURDAY...THEN FALL BELOW 10 FT BY
SUNDAY. SEAS TODAY WILL BE CHOPPY WITH AROUND 8 SECOND PERIODS
FROM THE SOUTHWEST. PERIODS WILL LENGTHEN TO AROUND 14 SECONDS
LATER TODAY AND TONIGHT...THEN SHIFT AND BE FROM THE NORTHWEST
WITH PERIODS AND 10 OR 11 SECONDS FRIDAY NIGHT INTO SATURDAY. PT
&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...GALE WARNING UNTIL 4 AM PST EARLY THIS MORNING FOR COASTAL
     WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT 60 NM.

     GALE WARNING UNTIL 7 AM PST THIS MORNING FOR COASTAL WATERS
     FROM CASCADE HEAD OR TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL
     6 AM PST FRIDAY.

&&


&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...GALE WARNING UNTIL 4 AM PST THURSDAY FOR COASTAL WATERS FROM
     CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 4 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 271128
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
327 AM PST THU NOV 27 2014

.SYNOPSIS...A WEAK COLD FRONT WILL PUSH SLOWLY INLAND TODAY. THE
FRONT WILL THEN STALL OVER SOUTH-CENTRAL OREGON TONIGHT AND FRI. THIS
FRONT WILL BEGIN TO LIFT NORTHWARD AGAIN EARLY FRI. ANOTHER STRONGER
COLD FRONT WILL MOVE S THROUGH THE REGION LATE FRI INTO SAT. THIS
FRONT WILL USHER IN MUCH COLDER WEATHER. SNOW LEVELS WILL FALL
RAPIDLY SAT...WITH A RAIN/SNOW MIX A POSSIBILITY FOR THE INTERIOR
LOWLANDS. HIGH PRES OVER THE INTERIOR NW WILL TURN THE FLOW OFFSHORE
BY SUN FOR DRY AND COLD WEATHER. ANOTHER SYSTEM COMING UP FROM THE S
SOMETIME EARLY NEXT WEEK WILL ATTEMPT TO SPREAD SOME PRECIPITATION UP
OVER THE COLD AIR MASS LEFT OVER FROM THE WEEKEND.
&&

SHORT TERM...TODAY THROUGH SATURDAY...
BREEZY SOUTHERLY WINDS AHEAD OF AN APPROACHING COLD FRONT ARE KEEPING
EXCEPTIONALLY MILD CONDITIONS IN PLACE ACROSS SOUTHWEST OREGON AND
NORTHWEST OREGON THIS MORNING. IN FACT...THE TEMPS IN THE UPPER 50S TO
LOW 60S BEING OBSERVED ACROSS MUCH OF THE REGION AT CURRENT ARE VERY
CLOSE TO THE RECORD DAILY HIGH TEMPS FOR THE LAST WEEK OF NOVEMBER.
HOWEVER...THE PERIOD OF MILD WEATHER THAT WE HAVE BEEN EXPERIENCING
OVER THE PAST FEW DAYS WILL BE COMING TO AN END VERY SHORTLY.

THE COLD FRONT APPROACHING THE COAST THIS MORNING IS NOT TERRIBLY
IMPRESSIVE. LOOKING AT THE LATEST IR SATELLITE IMAGERY...IT IS
APPARENT THAT THE UPPER LEVEL FRONT AND ASSOCIATED MOISTURE HAS MOVED
OUT AHEAD OF THE SURFACE FRONTAL BOUNDARY. THE SURFACE FRONT CAN BE
MADE OUT ON SATELLITE JUST OFFSHORE AROUND BUOY 29. WITH ONLY SHALLOW
MOISTURE REMAINING AND LITTLE IN THE WAY OF FORCING ALOFT...THE
ASSOCIATED PRECIPITATION THAT IS MOVING ONSHORE IS DEFINITELY ON THE
PATCHIER SIDE. THE RAIN HAS BECOME A BIT STEADIER OVER THE PAST FEW
HOURS ALONG THE N COAST AND COAST RANGE...BUT MOST SITES ARE ONLY
PICKING UP A FEW HUNDREDTHS OF AN INCH OF RAIN PER HOUR.
STILL...EXPECT MOST LOCATIONS WILL SEE A DECENT STEADY RAIN AS THE
FRONT PUSHES ONSHORE THIS MORNING AND THEN MOVES INLAND THROUGH THE
DAY. THE FRONT WILL EVENTUALLY STALL OVER SOUTHERN AND CENTRAL OREGON
LATER THIS AFTERNOON AND THIS EVENING.

THE OTHER FEATURE OF INTEREST THAT WE ARE WATCHING THIS MORNING IS A
PERSISTENT STATIONARY BAROCLINIC ZONE THAT IS CURRENTLY DRAPED OVER
BRITISH COLUMBIA AND FAR NORTHERN WASHINGTON. AN UPPER LEVEL TROUGH
WILL DRIVE THIS BOUNDARY SOUTHWARD FRI AND FRI NIGHT AS A SHARP COLD
FRONT. AT THE SAME TIME...THE STALLED FRONT OVER CENTRAL OREGON IS
FCST TO PUSH NORTHWARD AGAIN FRI MORNING. BETWEEN THESE TWO FRONTAL
BOUNDARIES...EXPECT RAINFALL TO STEADILY INCREASE AS THE DAY
PROGRESSES FRI. AS THE SHARP COLD FRONT FROM THE NORTH DIVES THROUGH
THE REGION LATER FRI AND FRI NIGHT...A MUCH COLDER AIR MASS ALOFT
WILL MOVE INTO THE REGION.

THE PARENT UPPER LEVEL TROUGH WILL SWING INTO THE REGION FROM THE
NORTH ON SAT TO PROVIDE SOME UPPER LEVEL SUPPORT FOR POST FRONTAL
SHOWER ACTIVITY...WHILE LOW LEVEL ONSHORE FLOW SHOULD PROVIDE
ADDITIONAL MOISTURE TO KEEP SHOWERS GOING THROUGH MUCH OF THE DAY.
BASED ON MODEL 850MB TEMPS AND 1000-500 MB THICKNESS VALUES...IT
APPEARS THAT THERE IS THE POTENTIAL FOR A RAIN/SNOW MIX TO AFFECT THE
INTERIOR LOWLANDS AT TIMES ON SAT. THE TEMP AND THICKNESS INDICATORS
ARE ONLY MARGINAL AND THERE IS SOME UNCERTAINTY AMONGST THE MODELS
JUST HOW COLD THE AIR MASS WILL BE...SO CONFIDENCE IS NOT ALL THAT
HIGH THAT THE INTERIOR LOWLANDS WILL SEE ANY SIGNIFICANT FLAKES. AT
ANY RATE...WITH THE MILD TEMPS WE HAVE SEEN OVER THE PAST FEW DAYS IT
IS UNLIKELY THAT ROAD SURFACES WILL BE ABLE TO COOL FAST ENOUGH FOR
THERE TO BE MAJOR TRAVEL CONCERNS. PYLE


LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY...MOST GUIDANCE
SUGGESTS THE UPPER TROUGH AXIS RESPONSIBLE FOR SATURDAYS SHOWERS WILL
BE MOVING ACROSS THE CASCADES SAT NIGHT...  ITH ANY LINGERING SHOWERS
COMING TO END OVERNIGHT. EXPECT SOME CLEARING SAT NIGHT AS COLD HIGH
PRESSURE BUILDS DOWN FROM BRITISH COLUMBIA...WITH LOW TEMPS LIKELY
GETTING WELL INTO THE 20S FOR MOST SPOTS. WITH HIGH PRESSURE
STRENGTHENING EAST OF THE CASCADES...EXPECT STRONG EAST WINDS TO RAMP
UP THROUGH THE GORGE SUNDAY MORNING AND PERSIST FOR MUCH OF THE
PERIOD THROUGH WEDNESDAY...WITH BREEZY CONDITIONS SPILLING INTO THE
PORTLAND/VANCOUVER METRO. MONDAY MAY BE A BRIEF BREAK FROM THE WINDS
AS A SYSTEM PASSES BY TO OUR NORTH.

MEANWHILE...A DISTURBANCE FROM THE ALEUTIANS IS EXPECTED TO CUT OFF
FROM THE MAIN PACIFIC JET AND SETTLE OFF THE CALIFORNIA COAST BY
SUNDAY...WHERE IT WILL LIKELY LINGER FOR A COUPLE DAYS. THERE IS A
CHANCE THIS SYSTEM COULD COME CLOSE ENOUGH TO SPREAD SOME PRECIP
NORTHWARD INTO OUR FORECAST AREA EARLY NEXT WEEK. IF THIS
OCCURS...THERE MAY BE SOME LIGHT FREEZING RAIN IN PORTIONS OF THE
WILLAMETTE VALLEY WITH SOME SNOW OR LIGHT FREEZING RAIN IN THE
GORGE. CUTOFF LOWS SUCH AS THIS ONE ARE NOTORIOUSLY DIFFICULT TO
FORECAST...AS MODELS STRUGGLE WITH THEM IN THE EXTENDED FORECAST
PERIOD. WHERE THIS UPPER LOW GOES WILL DICTATE THE WEATHER THROUGH
MIDWEEK...BUT TEMPS ARE EXPECTED TO SLOWLY MODERATE TUESDAY AND
WEDNESDAY.  WEAGLE
&&

.AVIATION...A MIXTURE OF IFR AND LOW MVFR CONDITIONS HAVE SPREAD
ONTO THE COAST WITH THE FIRST INCOMING COLD FRONT EARLY THIS
MORNING. CONDITIONS AT THE COAST WILL THEN CONTINUE IN THAT RANGE
INTO FRIDAY AS THE FRONT MOVES ONSHORE BUT STALLS AND SOME
PRECIPITATION CONTINUES AT TIMES. INLAND CONDITIONS ARE STILL VFR
EARLY THIS MORNING BUT WILL PROBABLY SEE SOME MVFR CONDITIONS AS
THE FRONT MOVES THROUGH TODAY. THE FRONT STALLS AND WEAKENS OVER
THE INLAND AREAS THIS AFTERNOON AND TONIGHT BEFORE THE NEXT FRONT
APPROACHES FROM THE NORTH ON FRIDAY. MODEL GUIDANCE SUGGESTS MVFR
CIGS OR LOW END VFR CIGS WILL CONTINUE OVER THE AREA BEHIND THE
FRONT INTO FRIDAY.

KPDX AND APPROACHES...VFR CONDITIONS EARLY THIS MORNING BUT EXPECT
PERIODIC MVFR CIGS TO DEVELOP THE REMAINDER OF THE MORNING. DO NOT
EXPECT MUCH CHANGE THE REMAINDER OF TODAY AND TONIGHT AS CIGS
HOVER BETWEEN MVFR AND LOW END VFR WITH SOME LIGHT PRECIPITATION
AT TIMES. PT
&&

.MARINE...WINDS HAVE PICKED UP AS THE FRONT MOVED FARTHER INTO THE
COASTAL WATERS OVERNIGHT...AND GALE WARNING LOOKS GOOD. BELIEVE
WINDS IN THE CENTRAL OREGON WATERS WILL EXTEND AN HOUR OR TWO
PAST 4 AM SO HAVE EXTENDED THE GALE THERE. THE FIRST COLD FRONT
MOVES ONSHORE THIS MORNING WHICH WILL ALLOW THE WINDS TO EAST A
BIT...BUT THERE IS REALLY NOT MUCH COLD AIR BEHIND THIS FRONT.
THEN IT LOOKS LIKE SMALL CRAFT ADVISORY WINDS FROM THE SOUTHWEST
FOR THE REMAINDER OF TODAY...TONIGHT...INTO FRIDAY. A SECONDARY
COLD FRONT WHICH HAS MUCH COLDER AIR BEHIND IT WILL MOVE SOUTH
THROUGH THE COASTAL WATERS FRIDAY AND EARLY FRIDAY EVENING FOR
CONTINUED SMALL CRAFT ADVISORY WINDS...WITH WIND DIRECTIONS
SWITCHING TO THE NORTHWEST BEHIND THIS FRONT. THE NORTHWEST WINDS
WILL EASE ON SATURDAY...THEN OFFSHORE GAP ENHANCED EAST WINDS WILL
DEVELOP SATURDAY NIGHT AND SUNDAY...PROBABLY OF THE SMALL CRAFT
ADVISORY VARIETY. THESE OFFSHORE WINDS WILL CONTINUE INTO NEXT
WEEK.

SEAS ARE RUNNING AROUND 10 FEET RIGHT NOW BUT ARE EXPECTED TO RUN
IN THE 10 TO 13 FT RANGE TODAY INTO FRIDAY...THEN CONTINUE TO
HOVER AROUND 10 FT INTO SATURDAY...THEN FALL BELOW 10 FT BY
SUNDAY. SEAS TODAY WILL BE CHOPPY WITH AROUND 8 SECOND PERIODS
FROM THE SOUTHWEST. PERIODS WILL LENGTHEN TO AROUND 14 SECONDS
LATER TODAY AND TONIGHT...THEN SHIFT AND BE FROM THE NORTHWEST
WITH PERIODS AND 10 OR 11 SECONDS FRIDAY NIGHT INTO SATURDAY. PT
&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...GALE WARNING UNTIL 4 AM PST EARLY THIS MORNING FOR COASTAL
     WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT 60 NM.

     GALE WARNING UNTIL 7 AM PST THIS MORNING FOR COASTAL WATERS
     FROM CASCADE HEAD OR TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL
     6 AM PST FRIDAY.

&&


&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...GALE WARNING UNTIL 4 AM PST THURSDAY FOR COASTAL WATERS FROM
     CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 4 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 KSEW 271122
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
330 AM PST THU NOV 27 2014

.SYNOPSIS...MOIST ONSHORE FLOW WILL GIVE PERIODS OF RAIN TO THE AREA
TODAY. A COLD FRONT WILL MOVE SOUTHEAST ACROSS THE AREA FRIDAY
MORNING GIVING FALLING TEMPERATURES DURING THE AFTERNOON. A STRONG
COLD FRONT WILL MOVE SOUTH THROUGH THE AREA FRIDAY NIGHT INTO
SATURDAY. SOME SNOW OR RAIN AND SNOW MIXED IS LIKELY TO OCCUR ALONG
THIS SECOND FRONT LATE FRIDAY NIGHT INTO SATURDAY. STRONG FRASER
OUTFLOW WILL GIVE WINDY CONDITIONS TO THE NORTH INTERIOR LATE FRIDAY
NIGHT INTO SATURDAY. COOL AND MAINLY DRY WEATHER IS EXPECTED SUNDAY
THROUGH EARLY NEXT WEEK.

&&

.SHORT TERM...VERY ACTIVE AND CHANGEABLE WEATHER IS EXPECTED OVER
THE AREA DURING THE SHORT TERM PERIOD.

A FRONTAL FEATURE MOVED INLAND THROUGH THE AREA EARLY THIS MORNING.
WHILE IT HAS BEEN WINDY ACROSS THE NORTH INTERIOR AND ALONG THE
NORTH COAST...WINDS HAVE BEEN BELOW WIND ADVISORY CRITERIA. WILL
ALLOW THE WIND ADVISORY TO EXPIRE AT 4 AM PST.

WHILE A WEAK FRONTAL SYSTEM IS MOVING ACROSS THE AREA EARLY THIS
MORNING...THE AIR MASS BEHIND THE FRONT IS ORIGINATING FROM THE
SUBTROPICAL CENTRAL PACIFIC. SO...WE CAN EXPECT A CONTINUATION OF
THE RATHER WARM AND MUGGY AIR MASS THAT WE HAVE SEEN OVER THE PAST
24 HOURS WITH TEMPERATURES REMAINING NEAR STEADY IN THE 50S THROUGH
TONIGHT. STRONG ONSHORE PRESSURE GRADIENTS AND THE HIGH MOISTURE
CONTENT OF THE LOW LEVEL AIR MASS - WITH DEWPOINTS AROUND 50 - IS
RESULTING IN GOOD OROGRAPHIC PRECIPITATION AMOUNTS ON THE WEST
SLOPES OF THE MOUNTAINS. LITTLE CHANGE IN THE OVERALL PATTERN IS
EXPECTED THROUGH TONIGHT...WITH POSSIBLY SOME INCREASE IN ONSHORE
FLOW TONIGHT AS A WAVE OF LOW PRESSURE MOVES BY TO THE NORTH OF THE
AREA. SEE THE HYDROLOGY SECTION BELOW FOR DETAILS ON FORECAST
PRECIPITATION IN THE AREA AND ITS IMPACT ON LOCAL RIVER.

BIG CHANGES BEGIN TO OCCUR FRIDAY MORNING. A WEAK UPPER LEVEL
TROUGH THAT IS PASSING SOUTHWARD THROUGH THE ALASKAN PANHANDLE THIS
MORNING IS FORECAST BY ALL MODELS TO SHARPEN AND DIG INTO WESTERN
WASHINGTON FRIDAY AFTERNOON. THIS WILL INTENSIFY THE FRONTAL SYSTEM
THAT NOW SITS OVER THE QUEEN CHARLOTTE SOUND AND SWEEP IT SOUTHEAST
ACROSS THE AREA FRIDAY MORNING. STRONG HEIGHT FALLS AT 500 MB BEGIN
FRIDAY MORNING AND CONTINUE THROUGH FRIDAY NIGHT...FALLING FROM NEAR
550 DAM TO AROUND 520 DAM PER THE 00Z ECMWF SOLUTION. THE GFS SHOWS
HEIGHT FALLS A BIT WEAKER THAN THE ECMWF...BUT IS STILL VERY
IMPRESSIVE AND IS RATHER CONSISTENT. SO A SHARP FRONT MOVES SE
ACROSS THE AREA DURING THE DAY WITH EARLY MORNING HIGH TEMPERATURES
IN MOST AREAS. PRECIPITATION AMOUNTS WITH THE FRONT PER MESOSCALE
MODELS LIKE THE UW WRFGFS ARE IMPRESSIVE FRIDAY MORNING. MOST AREAS
WILL BE BREEZY TO WINDY THROUGH FRIDAY.

A MODIFIED ARCTIC COLD FRONT WILL LIKELY REACH THE FAR NORTH
INTERIOR EARLY FRIDAY EVENING THEN TAKE ITS TIME MOVING SOUTH TO
AROUND EVERETT ABOUT MIDNIGHT FRIDAY NIGHT AND THROUGH THE SEATTLE
AREA SATURDAY MORNING. THIS FRONT WILL BE ACCOMPANIED BY A SHARP
UPPER LEVEL TROUGH AND POSSIBLY A LEE SIDE LOW THAT FORMS OFF
VANCOUVER ISLAND AND MOVES INLAND SOMEWHERE AROUND THE SOUTH
INTERIOR SATURDAY MORNING. A CONVERGENCE ZONE-LIKE FEATURE CAN BE
EXPECTED AHEAD OF THE MODIFIED ARCTIC FRONT. SNOW LEVELS WILL FALL
FRIDAY NIGHT...MOSTLY DUE TO THE COOLING ALOFT...THEN SHOULD BE NEAR
SEA LEVEL SATURDAY MORNING ALL AREAS. SNOWFALL AMOUNTS IN THE
LOWLANDS ARE HIGHLY UNCERTAIN AT THIS TIME. FORECAST MODELS RANGE
FROM ABOUT AN INCH IN THE GFS SOLUTION TO POSSIBLY 3 TO 5 INCHES
OVER PORTIONS OF THE NORTH INTERIOR DOWN TO THE NORTHERN PORTIONS OF
SEATTLE PER THE ECMWF...NAM12 AND CANADIAN SOLUTIONS. CURRENT
FORECASTS WILL BE A MODEL BLEND BETWEEN THESE AMOUNTS AND WILL
LIKELY NEED TO BE ADJUSTED AS WE GET CLOSER TO THE EVENT.

BEHIND THE MODIFIED ARCTIC FRONT...STRONG FRASER OUTFLOW WILL AFFECT
THE NORTH INTERIOR. MODELS GENERALLY AGREE THAT BELLINGHAM TO
WILLIAMS LAKE PRESSURE GRADIENTS WILL FALL TO -18 TO -23 MB. THIS
WOULD RESULT IN N TO NE WINDS 25 TO 40 MPH WITH GUSTS TO 55 MPH SAT
MORNING BELLINGHAM NORTHWARD AND IN THE SAN JUANS.

WILL ISSUE A SPECIAL WEATHER STATEMENT FOR THE RAPIDLY CHANGING
CONDITIONS...POSSIBLE LOWLAND SNOW...AND LOCALLY VERY WINDY
CONDITIONS FRIDAY THROUGH SATURDAY. ALBRECHT

.LONG TERM...AFTER A COLD MORNING ON SUNDAY...EXPECT GRADUALLY
MODERATING CONDITIONS LATER SUNDAY THROUGH EARLY NEXT WEEK. MODELS
VERY ON PRECIPITATION THREATS STARTING MONDAY WITH THE GFS BRINGING
SOUTHERN STREAM MOISTURE INTO OREGON AND FAR SOUTHERN WASHINGTON AND
THE ECMWF AND CANADIAN SOLUTIONS BRINGING A NORTHERN STREAM TROUGH
ACROSS THE AREA DURING THE SAME PERIOD. AT THIS TIME THE DRY
FORECAST WAS MAINTAINED BUT CLOUDS WERE INCREASED. ALBRECHT

&&

.HYDROLOGY...THE SNOQUALMIE RIVER NEAR CARNATION REMAINS ABOVE FLOOD
STAGE AS A RESULT OF THE HEAVY RAIN THAT FELL MONDAY AFTERNOON
THROUGH TUESDAY NIGHT...BUT IT IS FALLING AND WILL DROP BELOW FLOOD
STAGE IN A FEW HOURS.

RAIN BEGAN SPREADING INTO WESTERN WASHINGTON AHEAD OF THE NEXT
FRONTAL SYSTEM LATE WEDNESDAY. AS EXPECTED THE HEAVIEST RAIN HAS
BEEN OVER THE SOUTHWEST FACING SLOPES OF THE OLYMPICS...AND IN THE
CASCADES FROM ROUGHLY THE SNOHOMISH BASIN NORTHWARD. MANY STATIONS
THERE ARE REPORTING 0.6 TO 1.3 INCHES IN THE LAST 12 HOURS...AND
MOST OF THE RIVERS IN THE REGION HAVE STARTED RISING AGAIN.

SIGNIFICANT PRECIPITATION WILL CONTINUE THROUGH FRIDAY...WITH STRONG
OROGRAPHIC FORCING AS SOUTHWESTERLY LOW LEVEL WINDS OF 40 KT OR SO
CONTINUE. THE HEAVIEST PRECIPITATION WILL BE OVER THE OLYMPICS AND
NORTH CASCADES TODAY AND MOST OF TONIGHT...AND THEN THE FRONTAL BAND
AND HEAVIEST RAIN WILL GRADUALLY SHIFT SOUTHWARD ON FRIDAY. THE SNOW
LEVEL WILL BE 5500 TO 7000 FT THROUGH TONIGHT...AND IT SHOULD FALL
GRADUALLY ON FRIDAY AS THE COLD FRONT STARTS TO MOVE SOUTHEAST
THROUGH THE AREA.

ANOTHER 3.0 TO 5.5 INCHES OF PRECIPITATION IS LIKELY IN THE OLYMPICS
AND CASCADES FROM THE SNOHOMISH BASIN NORTHWARD THROUGH FRIDAY. THIS
COULD CAUSE THE SKOKOMISH RIVER TO FLOOD...AND IT COULD REACH FLOOD
STAGE THIS EVENING. IN THE NORTH CASCADES...THE NOOKSACK AND SKAGIT
RIVERS CAME CLOSE TO FLOODING ON WEDNESDAY...AND BOTH FACE A THREAT
OF FLOODING IN THIS EPISODE. IN ADDITION THE STILLAGUAMISH...
SKYKOMISH...TOLT...SNOQUALMIE...AND SNOHOMISH RIVERS -- ALL OF WHICH
FLOODED OR NEARLY FLOODED IN THE PAST COUPLE DAYS -- COULD FLOOD AS
WELL. FLOODING ON THESE CASCADE RIVERS WOULD PROBABLY BEGIN TONIGHT
OR FRIDAY. A MAJOR FLOODING EPISODE IS UNLIKELY...BUT IT WOULD BE NO
SURPRISE IF MANY OF THESE RIVERS HAVE MINOR TO MODERATE FLOODING.

THE CASCADES SOUTH OF THE SNOHOMISH BASIN WILL PROBABLY RECEIVE 2 TO
4 INCHES OF RAIN. MOST OF THAT COULD FALL ON FRIDAY AND SOME MODELS
-- ESPECIALLY THE UW WRF-GFS -- SHOW FAIRLY INTENSE RAINFALL IN THAT
AREA. SO THE RIVERS THERE FACE A THREAT OF FLOODING AS WELL. OF
COURSE SOME OF THEM RECENTLY FLOODED...AND THEY ARE ALL RUNNING
HIGH.

THE COLD FRONT SHOULD MOVE SOUTHEAST OF WESTERN WASHINGTON FRIDAY
NIGHT...WITH COLD AND DRIER WEATHER LIKELY THIS WEEKEND. RIVERS
SHOULD THEN RECEDE AND THE FLOOD THREAT WILL END FOR THE FORESEEABLE
FUTURE.   MCDONNAL

&&

.AVIATION...EXPECT RAIN AT TIMES THIS MORNING AS A COLD FRONT PUSHES
THROUGH WESTERN WA. THE FLOW ALOFT IS WESTERLY. MVFR CIGS ARE
POSSIBLE THIS MORNING IN -RA. GUSTY SOUTH WINDS ARE ALSO EXPECTED
WITH THIS FRONT. MOIST WESTERLY FLOW WILL CONTINUE THIS AFTERNOON
WITH SHOWERS MAINLY AFFECTING THE COAST AND MOUNTAINS. RAIN WILL
CONTINUE TONIGHT AS ANOTHER COLD FRONT SHIFTS S/SE INTO WESTERN WA.
33

KSEA...EXPECT LIGHT RAIN AT TIMES TODAY WITH CIGS NEAR 3000 FT.
GUSTY SOUTH WINDS 20015G25KT EXPECTED AT THE TERMINAL THROUGHOUT THE
DAY. 33

&&

.MARINE...A COLD FRONT IS PUSHING THROUGH WESTERN WA EARLY THIS
MORNING WITH MODERATE SOUTH/SOUTHWEST WINDS ACROSS THE WATERS -
SMALL CRAFT ADVISORIES ARE IN EFFECT FOR ALL ZONES. PRESSURE
GRADIENTS WILL REMAIN TIGHT TONIGHT THROUGH FRI MORNING AS ANOTHER
COLD FRONT SHIFTS SOUTH INTO WESTERN WA. STRONG HIGH PRES OVER
INTERIOR B.C. WILL BRING N/NE FRASER RIVER OUTFLOW WINDS LATE FRI
NIGHT INTO SAT WITH GALES POSSIBLE OVER THE NORTHERN INLAND WATERS.
OFFSHORE FLOW WILL PREVAIL SUN AND MON WITH HIGH PRES EAST OF THE
CASCADES. 33

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...FLOOD WATCHES AND WARNINGS IN EFFECT FOR PORTIONS OF
      WESTERN WASHINGTON.

PZ...SMALL CRAFT ADVISORY ALL WATERS.
     SMALL CRAFT ADVISORY GRAYS HARBOR BAR FOR ROUGH 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 271122
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
330 AM PST THU NOV 27 2014

.SYNOPSIS...MOIST ONSHORE FLOW WILL GIVE PERIODS OF RAIN TO THE AREA
TODAY. A COLD FRONT WILL MOVE SOUTHEAST ACROSS THE AREA FRIDAY
MORNING GIVING FALLING TEMPERATURES DURING THE AFTERNOON. A STRONG
COLD FRONT WILL MOVE SOUTH THROUGH THE AREA FRIDAY NIGHT INTO
SATURDAY. SOME SNOW OR RAIN AND SNOW MIXED IS LIKELY TO OCCUR ALONG
THIS SECOND FRONT LATE FRIDAY NIGHT INTO SATURDAY. STRONG FRASER
OUTFLOW WILL GIVE WINDY CONDITIONS TO THE NORTH INTERIOR LATE FRIDAY
NIGHT INTO SATURDAY. COOL AND MAINLY DRY WEATHER IS EXPECTED SUNDAY
THROUGH EARLY NEXT WEEK.

&&

.SHORT TERM...VERY ACTIVE AND CHANGEABLE WEATHER IS EXPECTED OVER
THE AREA DURING THE SHORT TERM PERIOD.

A FRONTAL FEATURE MOVED INLAND THROUGH THE AREA EARLY THIS MORNING.
WHILE IT HAS BEEN WINDY ACROSS THE NORTH INTERIOR AND ALONG THE
NORTH COAST...WINDS HAVE BEEN BELOW WIND ADVISORY CRITERIA. WILL
ALLOW THE WIND ADVISORY TO EXPIRE AT 4 AM PST.

WHILE A WEAK FRONTAL SYSTEM IS MOVING ACROSS THE AREA EARLY THIS
MORNING...THE AIR MASS BEHIND THE FRONT IS ORIGINATING FROM THE
SUBTROPICAL CENTRAL PACIFIC. SO...WE CAN EXPECT A CONTINUATION OF
THE RATHER WARM AND MUGGY AIR MASS THAT WE HAVE SEEN OVER THE PAST
24 HOURS WITH TEMPERATURES REMAINING NEAR STEADY IN THE 50S THROUGH
TONIGHT. STRONG ONSHORE PRESSURE GRADIENTS AND THE HIGH MOISTURE
CONTENT OF THE LOW LEVEL AIR MASS - WITH DEWPOINTS AROUND 50 - IS
RESULTING IN GOOD OROGRAPHIC PRECIPITATION AMOUNTS ON THE WEST
SLOPES OF THE MOUNTAINS. LITTLE CHANGE IN THE OVERALL PATTERN IS
EXPECTED THROUGH TONIGHT...WITH POSSIBLY SOME INCREASE IN ONSHORE
FLOW TONIGHT AS A WAVE OF LOW PRESSURE MOVES BY TO THE NORTH OF THE
AREA. SEE THE HYDROLOGY SECTION BELOW FOR DETAILS ON FORECAST
PRECIPITATION IN THE AREA AND ITS IMPACT ON LOCAL RIVER.

BIG CHANGES BEGIN TO OCCUR FRIDAY MORNING. A WEAK UPPER LEVEL
TROUGH THAT IS PASSING SOUTHWARD THROUGH THE ALASKAN PANHANDLE THIS
MORNING IS FORECAST BY ALL MODELS TO SHARPEN AND DIG INTO WESTERN
WASHINGTON FRIDAY AFTERNOON. THIS WILL INTENSIFY THE FRONTAL SYSTEM
THAT NOW SITS OVER THE QUEEN CHARLOTTE SOUND AND SWEEP IT SOUTHEAST
ACROSS THE AREA FRIDAY MORNING. STRONG HEIGHT FALLS AT 500 MB BEGIN
FRIDAY MORNING AND CONTINUE THROUGH FRIDAY NIGHT...FALLING FROM NEAR
550 DAM TO AROUND 520 DAM PER THE 00Z ECMWF SOLUTION. THE GFS SHOWS
HEIGHT FALLS A BIT WEAKER THAN THE ECMWF...BUT IS STILL VERY
IMPRESSIVE AND IS RATHER CONSISTENT. SO A SHARP FRONT MOVES SE
ACROSS THE AREA DURING THE DAY WITH EARLY MORNING HIGH TEMPERATURES
IN MOST AREAS. PRECIPITATION AMOUNTS WITH THE FRONT PER MESOSCALE
MODELS LIKE THE UW WRFGFS ARE IMPRESSIVE FRIDAY MORNING. MOST AREAS
WILL BE BREEZY TO WINDY THROUGH FRIDAY.

A MODIFIED ARCTIC COLD FRONT WILL LIKELY REACH THE FAR NORTH
INTERIOR EARLY FRIDAY EVENING THEN TAKE ITS TIME MOVING SOUTH TO
AROUND EVERETT ABOUT MIDNIGHT FRIDAY NIGHT AND THROUGH THE SEATTLE
AREA SATURDAY MORNING. THIS FRONT WILL BE ACCOMPANIED BY A SHARP
UPPER LEVEL TROUGH AND POSSIBLY A LEE SIDE LOW THAT FORMS OFF
VANCOUVER ISLAND AND MOVES INLAND SOMEWHERE AROUND THE SOUTH
INTERIOR SATURDAY MORNING. A CONVERGENCE ZONE-LIKE FEATURE CAN BE
EXPECTED AHEAD OF THE MODIFIED ARCTIC FRONT. SNOW LEVELS WILL FALL
FRIDAY NIGHT...MOSTLY DUE TO THE COOLING ALOFT...THEN SHOULD BE NEAR
SEA LEVEL SATURDAY MORNING ALL AREAS. SNOWFALL AMOUNTS IN THE
LOWLANDS ARE HIGHLY UNCERTAIN AT THIS TIME. FORECAST MODELS RANGE
FROM ABOUT AN INCH IN THE GFS SOLUTION TO POSSIBLY 3 TO 5 INCHES
OVER PORTIONS OF THE NORTH INTERIOR DOWN TO THE NORTHERN PORTIONS OF
SEATTLE PER THE ECMWF...NAM12 AND CANADIAN SOLUTIONS. CURRENT
FORECASTS WILL BE A MODEL BLEND BETWEEN THESE AMOUNTS AND WILL
LIKELY NEED TO BE ADJUSTED AS WE GET CLOSER TO THE EVENT.

BEHIND THE MODIFIED ARCTIC FRONT...STRONG FRASER OUTFLOW WILL AFFECT
THE NORTH INTERIOR. MODELS GENERALLY AGREE THAT BELLINGHAM TO
WILLIAMS LAKE PRESSURE GRADIENTS WILL FALL TO -18 TO -23 MB. THIS
WOULD RESULT IN N TO NE WINDS 25 TO 40 MPH WITH GUSTS TO 55 MPH SAT
MORNING BELLINGHAM NORTHWARD AND IN THE SAN JUANS.

WILL ISSUE A SPECIAL WEATHER STATEMENT FOR THE RAPIDLY CHANGING
CONDITIONS...POSSIBLE LOWLAND SNOW...AND LOCALLY VERY WINDY
CONDITIONS FRIDAY THROUGH SATURDAY. ALBRECHT

.LONG TERM...AFTER A COLD MORNING ON SUNDAY...EXPECT GRADUALLY
MODERATING CONDITIONS LATER SUNDAY THROUGH EARLY NEXT WEEK. MODELS
VERY ON PRECIPITATION THREATS STARTING MONDAY WITH THE GFS BRINGING
SOUTHERN STREAM MOISTURE INTO OREGON AND FAR SOUTHERN WASHINGTON AND
THE ECMWF AND CANADIAN SOLUTIONS BRINGING A NORTHERN STREAM TROUGH
ACROSS THE AREA DURING THE SAME PERIOD. AT THIS TIME THE DRY
FORECAST WAS MAINTAINED BUT CLOUDS WERE INCREASED. ALBRECHT

&&

.HYDROLOGY...THE SNOQUALMIE RIVER NEAR CARNATION REMAINS ABOVE FLOOD
STAGE AS A RESULT OF THE HEAVY RAIN THAT FELL MONDAY AFTERNOON
THROUGH TUESDAY NIGHT...BUT IT IS FALLING AND WILL DROP BELOW FLOOD
STAGE IN A FEW HOURS.

RAIN BEGAN SPREADING INTO WESTERN WASHINGTON AHEAD OF THE NEXT
FRONTAL SYSTEM LATE WEDNESDAY. AS EXPECTED THE HEAVIEST RAIN HAS
BEEN OVER THE SOUTHWEST FACING SLOPES OF THE OLYMPICS...AND IN THE
CASCADES FROM ROUGHLY THE SNOHOMISH BASIN NORTHWARD. MANY STATIONS
THERE ARE REPORTING 0.6 TO 1.3 INCHES IN THE LAST 12 HOURS...AND
MOST OF THE RIVERS IN THE REGION HAVE STARTED RISING AGAIN.

SIGNIFICANT PRECIPITATION WILL CONTINUE THROUGH FRIDAY...WITH STRONG
OROGRAPHIC FORCING AS SOUTHWESTERLY LOW LEVEL WINDS OF 40 KT OR SO
CONTINUE. THE HEAVIEST PRECIPITATION WILL BE OVER THE OLYMPICS AND
NORTH CASCADES TODAY AND MOST OF TONIGHT...AND THEN THE FRONTAL BAND
AND HEAVIEST RAIN WILL GRADUALLY SHIFT SOUTHWARD ON FRIDAY. THE SNOW
LEVEL WILL BE 5500 TO 7000 FT THROUGH TONIGHT...AND IT SHOULD FALL
GRADUALLY ON FRIDAY AS THE COLD FRONT STARTS TO MOVE SOUTHEAST
THROUGH THE AREA.

ANOTHER 3.0 TO 5.5 INCHES OF PRECIPITATION IS LIKELY IN THE OLYMPICS
AND CASCADES FROM THE SNOHOMISH BASIN NORTHWARD THROUGH FRIDAY. THIS
COULD CAUSE THE SKOKOMISH RIVER TO FLOOD...AND IT COULD REACH FLOOD
STAGE THIS EVENING. IN THE NORTH CASCADES...THE NOOKSACK AND SKAGIT
RIVERS CAME CLOSE TO FLOODING ON WEDNESDAY...AND BOTH FACE A THREAT
OF FLOODING IN THIS EPISODE. IN ADDITION THE STILLAGUAMISH...
SKYKOMISH...TOLT...SNOQUALMIE...AND SNOHOMISH RIVERS -- ALL OF WHICH
FLOODED OR NEARLY FLOODED IN THE PAST COUPLE DAYS -- COULD FLOOD AS
WELL. FLOODING ON THESE CASCADE RIVERS WOULD PROBABLY BEGIN TONIGHT
OR FRIDAY. A MAJOR FLOODING EPISODE IS UNLIKELY...BUT IT WOULD BE NO
SURPRISE IF MANY OF THESE RIVERS HAVE MINOR TO MODERATE FLOODING.

THE CASCADES SOUTH OF THE SNOHOMISH BASIN WILL PROBABLY RECEIVE 2 TO
4 INCHES OF RAIN. MOST OF THAT COULD FALL ON FRIDAY AND SOME MODELS
-- ESPECIALLY THE UW WRF-GFS -- SHOW FAIRLY INTENSE RAINFALL IN THAT
AREA. SO THE RIVERS THERE FACE A THREAT OF FLOODING AS WELL. OF
COURSE SOME OF THEM RECENTLY FLOODED...AND THEY ARE ALL RUNNING
HIGH.

THE COLD FRONT SHOULD MOVE SOUTHEAST OF WESTERN WASHINGTON FRIDAY
NIGHT...WITH COLD AND DRIER WEATHER LIKELY THIS WEEKEND. RIVERS
SHOULD THEN RECEDE AND THE FLOOD THREAT WILL END FOR THE FORESEEABLE
FUTURE.   MCDONNAL

&&

.AVIATION...EXPECT RAIN AT TIMES THIS MORNING AS A COLD FRONT PUSHES
THROUGH WESTERN WA. THE FLOW ALOFT IS WESTERLY. MVFR CIGS ARE
POSSIBLE THIS MORNING IN -RA. GUSTY SOUTH WINDS ARE ALSO EXPECTED
WITH THIS FRONT. MOIST WESTERLY FLOW WILL CONTINUE THIS AFTERNOON
WITH SHOWERS MAINLY AFFECTING THE COAST AND MOUNTAINS. RAIN WILL
CONTINUE TONIGHT AS ANOTHER COLD FRONT SHIFTS S/SE INTO WESTERN WA.
33

KSEA...EXPECT LIGHT RAIN AT TIMES TODAY WITH CIGS NEAR 3000 FT.
GUSTY SOUTH WINDS 20015G25KT EXPECTED AT THE TERMINAL THROUGHOUT THE
DAY. 33

&&

.MARINE...A COLD FRONT IS PUSHING THROUGH WESTERN WA EARLY THIS
MORNING WITH MODERATE SOUTH/SOUTHWEST WINDS ACROSS THE WATERS -
SMALL CRAFT ADVISORIES ARE IN EFFECT FOR ALL ZONES. PRESSURE
GRADIENTS WILL REMAIN TIGHT TONIGHT THROUGH FRI MORNING AS ANOTHER
COLD FRONT SHIFTS SOUTH INTO WESTERN WA. STRONG HIGH PRES OVER
INTERIOR B.C. WILL BRING N/NE FRASER RIVER OUTFLOW WINDS LATE FRI
NIGHT INTO SAT WITH GALES POSSIBLE OVER THE NORTHERN INLAND WATERS.
OFFSHORE FLOW WILL PREVAIL SUN AND MON WITH HIGH PRES EAST OF THE
CASCADES. 33

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...FLOOD WATCHES AND WARNINGS IN EFFECT FOR PORTIONS OF
      WESTERN WASHINGTON.

PZ...SMALL CRAFT ADVISORY ALL WATERS.
     SMALL CRAFT ADVISORY GRAYS HARBOR BAR FOR ROUGH BAR.

&&

$$

WWW.WEATHER.GOV/SEATTLE

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WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML









000
FXUS66 KSEW 271122
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
330 AM PST THU NOV 27 2014

.SYNOPSIS...MOIST ONSHORE FLOW WILL GIVE PERIODS OF RAIN TO THE AREA
TODAY. A COLD FRONT WILL MOVE SOUTHEAST ACROSS THE AREA FRIDAY
MORNING GIVING FALLING TEMPERATURES DURING THE AFTERNOON. A STRONG
COLD FRONT WILL MOVE SOUTH THROUGH THE AREA FRIDAY NIGHT INTO
SATURDAY. SOME SNOW OR RAIN AND SNOW MIXED IS LIKELY TO OCCUR ALONG
THIS SECOND FRONT LATE FRIDAY NIGHT INTO SATURDAY. STRONG FRASER
OUTFLOW WILL GIVE WINDY CONDITIONS TO THE NORTH INTERIOR LATE FRIDAY
NIGHT INTO SATURDAY. COOL AND MAINLY DRY WEATHER IS EXPECTED SUNDAY
THROUGH EARLY NEXT WEEK.

&&

.SHORT TERM...VERY ACTIVE AND CHANGEABLE WEATHER IS EXPECTED OVER
THE AREA DURING THE SHORT TERM PERIOD.

A FRONTAL FEATURE MOVED INLAND THROUGH THE AREA EARLY THIS MORNING.
WHILE IT HAS BEEN WINDY ACROSS THE NORTH INTERIOR AND ALONG THE
NORTH COAST...WINDS HAVE BEEN BELOW WIND ADVISORY CRITERIA. WILL
ALLOW THE WIND ADVISORY TO EXPIRE AT 4 AM PST.

WHILE A WEAK FRONTAL SYSTEM IS MOVING ACROSS THE AREA EARLY THIS
MORNING...THE AIR MASS BEHIND THE FRONT IS ORIGINATING FROM THE
SUBTROPICAL CENTRAL PACIFIC. SO...WE CAN EXPECT A CONTINUATION OF
THE RATHER WARM AND MUGGY AIR MASS THAT WE HAVE SEEN OVER THE PAST
24 HOURS WITH TEMPERATURES REMAINING NEAR STEADY IN THE 50S THROUGH
TONIGHT. STRONG ONSHORE PRESSURE GRADIENTS AND THE HIGH MOISTURE
CONTENT OF THE LOW LEVEL AIR MASS - WITH DEWPOINTS AROUND 50 - IS
RESULTING IN GOOD OROGRAPHIC PRECIPITATION AMOUNTS ON THE WEST
SLOPES OF THE MOUNTAINS. LITTLE CHANGE IN THE OVERALL PATTERN IS
EXPECTED THROUGH TONIGHT...WITH POSSIBLY SOME INCREASE IN ONSHORE
FLOW TONIGHT AS A WAVE OF LOW PRESSURE MOVES BY TO THE NORTH OF THE
AREA. SEE THE HYDROLOGY SECTION BELOW FOR DETAILS ON FORECAST
PRECIPITATION IN THE AREA AND ITS IMPACT ON LOCAL RIVER.

BIG CHANGES BEGIN TO OCCUR FRIDAY MORNING. A WEAK UPPER LEVEL
TROUGH THAT IS PASSING SOUTHWARD THROUGH THE ALASKAN PANHANDLE THIS
MORNING IS FORECAST BY ALL MODELS TO SHARPEN AND DIG INTO WESTERN
WASHINGTON FRIDAY AFTERNOON. THIS WILL INTENSIFY THE FRONTAL SYSTEM
THAT NOW SITS OVER THE QUEEN CHARLOTTE SOUND AND SWEEP IT SOUTHEAST
ACROSS THE AREA FRIDAY MORNING. STRONG HEIGHT FALLS AT 500 MB BEGIN
FRIDAY MORNING AND CONTINUE THROUGH FRIDAY NIGHT...FALLING FROM NEAR
550 DAM TO AROUND 520 DAM PER THE 00Z ECMWF SOLUTION. THE GFS SHOWS
HEIGHT FALLS A BIT WEAKER THAN THE ECMWF...BUT IS STILL VERY
IMPRESSIVE AND IS RATHER CONSISTENT. SO A SHARP FRONT MOVES SE
ACROSS THE AREA DURING THE DAY WITH EARLY MORNING HIGH TEMPERATURES
IN MOST AREAS. PRECIPITATION AMOUNTS WITH THE FRONT PER MESOSCALE
MODELS LIKE THE UW WRFGFS ARE IMPRESSIVE FRIDAY MORNING. MOST AREAS
WILL BE BREEZY TO WINDY THROUGH FRIDAY.

A MODIFIED ARCTIC COLD FRONT WILL LIKELY REACH THE FAR NORTH
INTERIOR EARLY FRIDAY EVENING THEN TAKE ITS TIME MOVING SOUTH TO
AROUND EVERETT ABOUT MIDNIGHT FRIDAY NIGHT AND THROUGH THE SEATTLE
AREA SATURDAY MORNING. THIS FRONT WILL BE ACCOMPANIED BY A SHARP
UPPER LEVEL TROUGH AND POSSIBLY A LEE SIDE LOW THAT FORMS OFF
VANCOUVER ISLAND AND MOVES INLAND SOMEWHERE AROUND THE SOUTH
INTERIOR SATURDAY MORNING. A CONVERGENCE ZONE-LIKE FEATURE CAN BE
EXPECTED AHEAD OF THE MODIFIED ARCTIC FRONT. SNOW LEVELS WILL FALL
FRIDAY NIGHT...MOSTLY DUE TO THE COOLING ALOFT...THEN SHOULD BE NEAR
SEA LEVEL SATURDAY MORNING ALL AREAS. SNOWFALL AMOUNTS IN THE
LOWLANDS ARE HIGHLY UNCERTAIN AT THIS TIME. FORECAST MODELS RANGE
FROM ABOUT AN INCH IN THE GFS SOLUTION TO POSSIBLY 3 TO 5 INCHES
OVER PORTIONS OF THE NORTH INTERIOR DOWN TO THE NORTHERN PORTIONS OF
SEATTLE PER THE ECMWF...NAM12 AND CANADIAN SOLUTIONS. CURRENT
FORECASTS WILL BE A MODEL BLEND BETWEEN THESE AMOUNTS AND WILL
LIKELY NEED TO BE ADJUSTED AS WE GET CLOSER TO THE EVENT.

BEHIND THE MODIFIED ARCTIC FRONT...STRONG FRASER OUTFLOW WILL AFFECT
THE NORTH INTERIOR. MODELS GENERALLY AGREE THAT BELLINGHAM TO
WILLIAMS LAKE PRESSURE GRADIENTS WILL FALL TO -18 TO -23 MB. THIS
WOULD RESULT IN N TO NE WINDS 25 TO 40 MPH WITH GUSTS TO 55 MPH SAT
MORNING BELLINGHAM NORTHWARD AND IN THE SAN JUANS.

WILL ISSUE A SPECIAL WEATHER STATEMENT FOR THE RAPIDLY CHANGING
CONDITIONS...POSSIBLE LOWLAND SNOW...AND LOCALLY VERY WINDY
CONDITIONS FRIDAY THROUGH SATURDAY. ALBRECHT

.LONG TERM...AFTER A COLD MORNING ON SUNDAY...EXPECT GRADUALLY
MODERATING CONDITIONS LATER SUNDAY THROUGH EARLY NEXT WEEK. MODELS
VERY ON PRECIPITATION THREATS STARTING MONDAY WITH THE GFS BRINGING
SOUTHERN STREAM MOISTURE INTO OREGON AND FAR SOUTHERN WASHINGTON AND
THE ECMWF AND CANADIAN SOLUTIONS BRINGING A NORTHERN STREAM TROUGH
ACROSS THE AREA DURING THE SAME PERIOD. AT THIS TIME THE DRY
FORECAST WAS MAINTAINED BUT CLOUDS WERE INCREASED. ALBRECHT

&&

.HYDROLOGY...THE SNOQUALMIE RIVER NEAR CARNATION REMAINS ABOVE FLOOD
STAGE AS A RESULT OF THE HEAVY RAIN THAT FELL MONDAY AFTERNOON
THROUGH TUESDAY NIGHT...BUT IT IS FALLING AND WILL DROP BELOW FLOOD
STAGE IN A FEW HOURS.

RAIN BEGAN SPREADING INTO WESTERN WASHINGTON AHEAD OF THE NEXT
FRONTAL SYSTEM LATE WEDNESDAY. AS EXPECTED THE HEAVIEST RAIN HAS
BEEN OVER THE SOUTHWEST FACING SLOPES OF THE OLYMPICS...AND IN THE
CASCADES FROM ROUGHLY THE SNOHOMISH BASIN NORTHWARD. MANY STATIONS
THERE ARE REPORTING 0.6 TO 1.3 INCHES IN THE LAST 12 HOURS...AND
MOST OF THE RIVERS IN THE REGION HAVE STARTED RISING AGAIN.

SIGNIFICANT PRECIPITATION WILL CONTINUE THROUGH FRIDAY...WITH STRONG
OROGRAPHIC FORCING AS SOUTHWESTERLY LOW LEVEL WINDS OF 40 KT OR SO
CONTINUE. THE HEAVIEST PRECIPITATION WILL BE OVER THE OLYMPICS AND
NORTH CASCADES TODAY AND MOST OF TONIGHT...AND THEN THE FRONTAL BAND
AND HEAVIEST RAIN WILL GRADUALLY SHIFT SOUTHWARD ON FRIDAY. THE SNOW
LEVEL WILL BE 5500 TO 7000 FT THROUGH TONIGHT...AND IT SHOULD FALL
GRADUALLY ON FRIDAY AS THE COLD FRONT STARTS TO MOVE SOUTHEAST
THROUGH THE AREA.

ANOTHER 3.0 TO 5.5 INCHES OF PRECIPITATION IS LIKELY IN THE OLYMPICS
AND CASCADES FROM THE SNOHOMISH BASIN NORTHWARD THROUGH FRIDAY. THIS
COULD CAUSE THE SKOKOMISH RIVER TO FLOOD...AND IT COULD REACH FLOOD
STAGE THIS EVENING. IN THE NORTH CASCADES...THE NOOKSACK AND SKAGIT
RIVERS CAME CLOSE TO FLOODING ON WEDNESDAY...AND BOTH FACE A THREAT
OF FLOODING IN THIS EPISODE. IN ADDITION THE STILLAGUAMISH...
SKYKOMISH...TOLT...SNOQUALMIE...AND SNOHOMISH RIVERS -- ALL OF WHICH
FLOODED OR NEARLY FLOODED IN THE PAST COUPLE DAYS -- COULD FLOOD AS
WELL. FLOODING ON THESE CASCADE RIVERS WOULD PROBABLY BEGIN TONIGHT
OR FRIDAY. A MAJOR FLOODING EPISODE IS UNLIKELY...BUT IT WOULD BE NO
SURPRISE IF MANY OF THESE RIVERS HAVE MINOR TO MODERATE FLOODING.

THE CASCADES SOUTH OF THE SNOHOMISH BASIN WILL PROBABLY RECEIVE 2 TO
4 INCHES OF RAIN. MOST OF THAT COULD FALL ON FRIDAY AND SOME MODELS
-- ESPECIALLY THE UW WRF-GFS -- SHOW FAIRLY INTENSE RAINFALL IN THAT
AREA. SO THE RIVERS THERE FACE A THREAT OF FLOODING AS WELL. OF
COURSE SOME OF THEM RECENTLY FLOODED...AND THEY ARE ALL RUNNING
HIGH.

THE COLD FRONT SHOULD MOVE SOUTHEAST OF WESTERN WASHINGTON FRIDAY
NIGHT...WITH COLD AND DRIER WEATHER LIKELY THIS WEEKEND. RIVERS
SHOULD THEN RECEDE AND THE FLOOD THREAT WILL END FOR THE FORESEEABLE
FUTURE.   MCDONNAL

&&

.AVIATION...EXPECT RAIN AT TIMES THIS MORNING AS A COLD FRONT PUSHES
THROUGH WESTERN WA. THE FLOW ALOFT IS WESTERLY. MVFR CIGS ARE
POSSIBLE THIS MORNING IN -RA. GUSTY SOUTH WINDS ARE ALSO EXPECTED
WITH THIS FRONT. MOIST WESTERLY FLOW WILL CONTINUE THIS AFTERNOON
WITH SHOWERS MAINLY AFFECTING THE COAST AND MOUNTAINS. RAIN WILL
CONTINUE TONIGHT AS ANOTHER COLD FRONT SHIFTS S/SE INTO WESTERN WA.
33

KSEA...EXPECT LIGHT RAIN AT TIMES TODAY WITH CIGS NEAR 3000 FT.
GUSTY SOUTH WINDS 20015G25KT EXPECTED AT THE TERMINAL THROUGHOUT THE
DAY. 33

&&

.MARINE...A COLD FRONT IS PUSHING THROUGH WESTERN WA EARLY THIS
MORNING WITH MODERATE SOUTH/SOUTHWEST WINDS ACROSS THE WATERS -
SMALL CRAFT ADVISORIES ARE IN EFFECT FOR ALL ZONES. PRESSURE
GRADIENTS WILL REMAIN TIGHT TONIGHT THROUGH FRI MORNING AS ANOTHER
COLD FRONT SHIFTS SOUTH INTO WESTERN WA. STRONG HIGH PRES OVER
INTERIOR B.C. WILL BRING N/NE FRASER RIVER OUTFLOW WINDS LATE FRI
NIGHT INTO SAT WITH GALES POSSIBLE OVER THE NORTHERN INLAND WATERS.
OFFSHORE FLOW WILL PREVAIL SUN AND MON WITH HIGH PRES EAST OF THE
CASCADES. 33

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...FLOOD WATCHES AND WARNINGS IN EFFECT FOR PORTIONS OF
      WESTERN WASHINGTON.

PZ...SMALL CRAFT ADVISORY ALL WATERS.
     SMALL CRAFT ADVISORY GRAYS HARBOR BAR FOR ROUGH 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 271122
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
330 AM PST THU NOV 27 2014

.SYNOPSIS...MOIST ONSHORE FLOW WILL GIVE PERIODS OF RAIN TO THE AREA
TODAY. A COLD FRONT WILL MOVE SOUTHEAST ACROSS THE AREA FRIDAY
MORNING GIVING FALLING TEMPERATURES DURING THE AFTERNOON. A STRONG
COLD FRONT WILL MOVE SOUTH THROUGH THE AREA FRIDAY NIGHT INTO
SATURDAY. SOME SNOW OR RAIN AND SNOW MIXED IS LIKELY TO OCCUR ALONG
THIS SECOND FRONT LATE FRIDAY NIGHT INTO SATURDAY. STRONG FRASER
OUTFLOW WILL GIVE WINDY CONDITIONS TO THE NORTH INTERIOR LATE FRIDAY
NIGHT INTO SATURDAY. COOL AND MAINLY DRY WEATHER IS EXPECTED SUNDAY
THROUGH EARLY NEXT WEEK.

&&

.SHORT TERM...VERY ACTIVE AND CHANGEABLE WEATHER IS EXPECTED OVER
THE AREA DURING THE SHORT TERM PERIOD.

A FRONTAL FEATURE MOVED INLAND THROUGH THE AREA EARLY THIS MORNING.
WHILE IT HAS BEEN WINDY ACROSS THE NORTH INTERIOR AND ALONG THE
NORTH COAST...WINDS HAVE BEEN BELOW WIND ADVISORY CRITERIA. WILL
ALLOW THE WIND ADVISORY TO EXPIRE AT 4 AM PST.

WHILE A WEAK FRONTAL SYSTEM IS MOVING ACROSS THE AREA EARLY THIS
MORNING...THE AIR MASS BEHIND THE FRONT IS ORIGINATING FROM THE
SUBTROPICAL CENTRAL PACIFIC. SO...WE CAN EXPECT A CONTINUATION OF
THE RATHER WARM AND MUGGY AIR MASS THAT WE HAVE SEEN OVER THE PAST
24 HOURS WITH TEMPERATURES REMAINING NEAR STEADY IN THE 50S THROUGH
TONIGHT. STRONG ONSHORE PRESSURE GRADIENTS AND THE HIGH MOISTURE
CONTENT OF THE LOW LEVEL AIR MASS - WITH DEWPOINTS AROUND 50 - IS
RESULTING IN GOOD OROGRAPHIC PRECIPITATION AMOUNTS ON THE WEST
SLOPES OF THE MOUNTAINS. LITTLE CHANGE IN THE OVERALL PATTERN IS
EXPECTED THROUGH TONIGHT...WITH POSSIBLY SOME INCREASE IN ONSHORE
FLOW TONIGHT AS A WAVE OF LOW PRESSURE MOVES BY TO THE NORTH OF THE
AREA. SEE THE HYDROLOGY SECTION BELOW FOR DETAILS ON FORECAST
PRECIPITATION IN THE AREA AND ITS IMPACT ON LOCAL RIVER.

BIG CHANGES BEGIN TO OCCUR FRIDAY MORNING. A WEAK UPPER LEVEL
TROUGH THAT IS PASSING SOUTHWARD THROUGH THE ALASKAN PANHANDLE THIS
MORNING IS FORECAST BY ALL MODELS TO SHARPEN AND DIG INTO WESTERN
WASHINGTON FRIDAY AFTERNOON. THIS WILL INTENSIFY THE FRONTAL SYSTEM
THAT NOW SITS OVER THE QUEEN CHARLOTTE SOUND AND SWEEP IT SOUTHEAST
ACROSS THE AREA FRIDAY MORNING. STRONG HEIGHT FALLS AT 500 MB BEGIN
FRIDAY MORNING AND CONTINUE THROUGH FRIDAY NIGHT...FALLING FROM NEAR
550 DAM TO AROUND 520 DAM PER THE 00Z ECMWF SOLUTION. THE GFS SHOWS
HEIGHT FALLS A BIT WEAKER THAN THE ECMWF...BUT IS STILL VERY
IMPRESSIVE AND IS RATHER CONSISTENT. SO A SHARP FRONT MOVES SE
ACROSS THE AREA DURING THE DAY WITH EARLY MORNING HIGH TEMPERATURES
IN MOST AREAS. PRECIPITATION AMOUNTS WITH THE FRONT PER MESOSCALE
MODELS LIKE THE UW WRFGFS ARE IMPRESSIVE FRIDAY MORNING. MOST AREAS
WILL BE BREEZY TO WINDY THROUGH FRIDAY.

A MODIFIED ARCTIC COLD FRONT WILL LIKELY REACH THE FAR NORTH
INTERIOR EARLY FRIDAY EVENING THEN TAKE ITS TIME MOVING SOUTH TO
AROUND EVERETT ABOUT MIDNIGHT FRIDAY NIGHT AND THROUGH THE SEATTLE
AREA SATURDAY MORNING. THIS FRONT WILL BE ACCOMPANIED BY A SHARP
UPPER LEVEL TROUGH AND POSSIBLY A LEE SIDE LOW THAT FORMS OFF
VANCOUVER ISLAND AND MOVES INLAND SOMEWHERE AROUND THE SOUTH
INTERIOR SATURDAY MORNING. A CONVERGENCE ZONE-LIKE FEATURE CAN BE
EXPECTED AHEAD OF THE MODIFIED ARCTIC FRONT. SNOW LEVELS WILL FALL
FRIDAY NIGHT...MOSTLY DUE TO THE COOLING ALOFT...THEN SHOULD BE NEAR
SEA LEVEL SATURDAY MORNING ALL AREAS. SNOWFALL AMOUNTS IN THE
LOWLANDS ARE HIGHLY UNCERTAIN AT THIS TIME. FORECAST MODELS RANGE
FROM ABOUT AN INCH IN THE GFS SOLUTION TO POSSIBLY 3 TO 5 INCHES
OVER PORTIONS OF THE NORTH INTERIOR DOWN TO THE NORTHERN PORTIONS OF
SEATTLE PER THE ECMWF...NAM12 AND CANADIAN SOLUTIONS. CURRENT
FORECASTS WILL BE A MODEL BLEND BETWEEN THESE AMOUNTS AND WILL
LIKELY NEED TO BE ADJUSTED AS WE GET CLOSER TO THE EVENT.

BEHIND THE MODIFIED ARCTIC FRONT...STRONG FRASER OUTFLOW WILL AFFECT
THE NORTH INTERIOR. MODELS GENERALLY AGREE THAT BELLINGHAM TO
WILLIAMS LAKE PRESSURE GRADIENTS WILL FALL TO -18 TO -23 MB. THIS
WOULD RESULT IN N TO NE WINDS 25 TO 40 MPH WITH GUSTS TO 55 MPH SAT
MORNING BELLINGHAM NORTHWARD AND IN THE SAN JUANS.

WILL ISSUE A SPECIAL WEATHER STATEMENT FOR THE RAPIDLY CHANGING
CONDITIONS...POSSIBLE LOWLAND SNOW...AND LOCALLY VERY WINDY
CONDITIONS FRIDAY THROUGH SATURDAY. ALBRECHT

.LONG TERM...AFTER A COLD MORNING ON SUNDAY...EXPECT GRADUALLY
MODERATING CONDITIONS LATER SUNDAY THROUGH EARLY NEXT WEEK. MODELS
VERY ON PRECIPITATION THREATS STARTING MONDAY WITH THE GFS BRINGING
SOUTHERN STREAM MOISTURE INTO OREGON AND FAR SOUTHERN WASHINGTON AND
THE ECMWF AND CANADIAN SOLUTIONS BRINGING A NORTHERN STREAM TROUGH
ACROSS THE AREA DURING THE SAME PERIOD. AT THIS TIME THE DRY
FORECAST WAS MAINTAINED BUT CLOUDS WERE INCREASED. ALBRECHT

&&

.HYDROLOGY...THE SNOQUALMIE RIVER NEAR CARNATION REMAINS ABOVE FLOOD
STAGE AS A RESULT OF THE HEAVY RAIN THAT FELL MONDAY AFTERNOON
THROUGH TUESDAY NIGHT...BUT IT IS FALLING AND WILL DROP BELOW FLOOD
STAGE IN A FEW HOURS.

RAIN BEGAN SPREADING INTO WESTERN WASHINGTON AHEAD OF THE NEXT
FRONTAL SYSTEM LATE WEDNESDAY. AS EXPECTED THE HEAVIEST RAIN HAS
BEEN OVER THE SOUTHWEST FACING SLOPES OF THE OLYMPICS...AND IN THE
CASCADES FROM ROUGHLY THE SNOHOMISH BASIN NORTHWARD. MANY STATIONS
THERE ARE REPORTING 0.6 TO 1.3 INCHES IN THE LAST 12 HOURS...AND
MOST OF THE RIVERS IN THE REGION HAVE STARTED RISING AGAIN.

SIGNIFICANT PRECIPITATION WILL CONTINUE THROUGH FRIDAY...WITH STRONG
OROGRAPHIC FORCING AS SOUTHWESTERLY LOW LEVEL WINDS OF 40 KT OR SO
CONTINUE. THE HEAVIEST PRECIPITATION WILL BE OVER THE OLYMPICS AND
NORTH CASCADES TODAY AND MOST OF TONIGHT...AND THEN THE FRONTAL BAND
AND HEAVIEST RAIN WILL GRADUALLY SHIFT SOUTHWARD ON FRIDAY. THE SNOW
LEVEL WILL BE 5500 TO 7000 FT THROUGH TONIGHT...AND IT SHOULD FALL
GRADUALLY ON FRIDAY AS THE COLD FRONT STARTS TO MOVE SOUTHEAST
THROUGH THE AREA.

ANOTHER 3.0 TO 5.5 INCHES OF PRECIPITATION IS LIKELY IN THE OLYMPICS
AND CASCADES FROM THE SNOHOMISH BASIN NORTHWARD THROUGH FRIDAY. THIS
COULD CAUSE THE SKOKOMISH RIVER TO FLOOD...AND IT COULD REACH FLOOD
STAGE THIS EVENING. IN THE NORTH CASCADES...THE NOOKSACK AND SKAGIT
RIVERS CAME CLOSE TO FLOODING ON WEDNESDAY...AND BOTH FACE A THREAT
OF FLOODING IN THIS EPISODE. IN ADDITION THE STILLAGUAMISH...
SKYKOMISH...TOLT...SNOQUALMIE...AND SNOHOMISH RIVERS -- ALL OF WHICH
FLOODED OR NEARLY FLOODED IN THE PAST COUPLE DAYS -- COULD FLOOD AS
WELL. FLOODING ON THESE CASCADE RIVERS WOULD PROBABLY BEGIN TONIGHT
OR FRIDAY. A MAJOR FLOODING EPISODE IS UNLIKELY...BUT IT WOULD BE NO
SURPRISE IF MANY OF THESE RIVERS HAVE MINOR TO MODERATE FLOODING.

THE CASCADES SOUTH OF THE SNOHOMISH BASIN WILL PROBABLY RECEIVE 2 TO
4 INCHES OF RAIN. MOST OF THAT COULD FALL ON FRIDAY AND SOME MODELS
-- ESPECIALLY THE UW WRF-GFS -- SHOW FAIRLY INTENSE RAINFALL IN THAT
AREA. SO THE RIVERS THERE FACE A THREAT OF FLOODING AS WELL. OF
COURSE SOME OF THEM RECENTLY FLOODED...AND THEY ARE ALL RUNNING
HIGH.

THE COLD FRONT SHOULD MOVE SOUTHEAST OF WESTERN WASHINGTON FRIDAY
NIGHT...WITH COLD AND DRIER WEATHER LIKELY THIS WEEKEND. RIVERS
SHOULD THEN RECEDE AND THE FLOOD THREAT WILL END FOR THE FORESEEABLE
FUTURE.   MCDONNAL

&&

.AVIATION...EXPECT RAIN AT TIMES THIS MORNING AS A COLD FRONT PUSHES
THROUGH WESTERN WA. THE FLOW ALOFT IS WESTERLY. MVFR CIGS ARE
POSSIBLE THIS MORNING IN -RA. GUSTY SOUTH WINDS ARE ALSO EXPECTED
WITH THIS FRONT. MOIST WESTERLY FLOW WILL CONTINUE THIS AFTERNOON
WITH SHOWERS MAINLY AFFECTING THE COAST AND MOUNTAINS. RAIN WILL
CONTINUE TONIGHT AS ANOTHER COLD FRONT SHIFTS S/SE INTO WESTERN WA.
33

KSEA...EXPECT LIGHT RAIN AT TIMES TODAY WITH CIGS NEAR 3000 FT.
GUSTY SOUTH WINDS 20015G25KT EXPECTED AT THE TERMINAL THROUGHOUT THE
DAY. 33

&&

.MARINE...A COLD FRONT IS PUSHING THROUGH WESTERN WA EARLY THIS
MORNING WITH MODERATE SOUTH/SOUTHWEST WINDS ACROSS THE WATERS -
SMALL CRAFT ADVISORIES ARE IN EFFECT FOR ALL ZONES. PRESSURE
GRADIENTS WILL REMAIN TIGHT TONIGHT THROUGH FRI MORNING AS ANOTHER
COLD FRONT SHIFTS SOUTH INTO WESTERN WA. STRONG HIGH PRES OVER
INTERIOR B.C. WILL BRING N/NE FRASER RIVER OUTFLOW WINDS LATE FRI
NIGHT INTO SAT WITH GALES POSSIBLE OVER THE NORTHERN INLAND WATERS.
OFFSHORE FLOW WILL PREVAIL SUN AND MON WITH HIGH PRES EAST OF THE
CASCADES. 33

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...FLOOD WATCHES AND WARNINGS IN EFFECT FOR PORTIONS OF
      WESTERN WASHINGTON.

PZ...SMALL CRAFT ADVISORY ALL WATERS.
     SMALL CRAFT ADVISORY GRAYS HARBOR BAR FOR ROUGH 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 271044
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
244 AM PST THU NOV 27 2014

.SYNOPSIS...
Mild and breezy weather is expected Thanksgiving with areas of
fog in the morning. Snow levels should rise above the mountain
passes. Motorists with plans to travel over the mountain passes
should experience good conditions today through Friday afternoon.
The arrival of a very cold and windy arctic front Friday Night
into Saturday will bring winter driving conditions to the mountain
passes and much cooler weather for the weekend.

&&

.DISCUSSION...

Today through Fri: The biggest changes to the fcst were to
decrease the amnt of pcpn for all non-mountain zones, increase the
winds, and warm temperatures a bit. Though by far the most
eventful part of the fcst will be Fri Nt through the weekend as
we deal with a significant cold front passage that will produce
snow for all elevations, gusty cold north winds and temps as low
as the single digits, we have some relatively mild, but windy
weather to deal with first. Currently behind a cool frontal
passage late yesterday, we`re still anticipating sfc winds to
increase slowly and help to mix out any dense fog now in the Upper
Columbia Basin. We`ve extended the dense fog advsy a few more
hours and will be watched carefully. The good news is that temps
are above freezing, so very slick roads shouldn`t be a big problem
on this important Thanksgiving day travel morning. Today and
Friday all of Ern Wa and N Id will be in a mild pre-arctic cold
front air mass, with well- above normal temps. However, this same
pattern typically favors very gusty winds. This time it`s no
different. Most model guidance shows persistent 850mb winds
(roughly 5k ft above the sfc) from the southwest at 35-45kt.
Expect these winds to begin to increase this morning. Temps will
be mild, even low temps for areas that manage to remain coupled
with these winds aloft (non- valley sites). bz

Friday night through Sunday...The wet but mild weather pattern
will come to an end as an arctic front slides south across the
region bringing much colder and drier air with it. A strong
surface low will slide south across eastern WA and north ID Friday
night, bringing a good chance of precipitation to the eastern half
of the forecast area along with strong gusty southwest winds. Snow
levels will start out around 5k ft Friday evening then come
crashing down overnight. The bulk of the precip will fall as rain
in the valleys. By the time the cold air moves in, the low will be
over central Idaho with showers limited to the southeast zones.
The Camas Prairie may see some low end advisory snowfall but even
this amount is uncertain.

On Saturday the exiting low and building high pressure over
southern BC will set up a strong surface pressure gradient that
will channel northerly winds down the Okanogan Valley and Purcell
Trench and into the basin. This pattern shows the potential for
wind highlights and will continue to be monitored. Saturday
morning temperatures will likely be the high for the day as the
frigid air continues to march south across the area. The rest of
the weekend will continue the cold and dry trend with lows in the
single digits across the northern zones. Valley highs in the 20s
will be common.

Sunday night through Wednesday...The cold temperatures will start
to moderate as northerly winds are replaced by more westerly flow.
Model solutions diverge when it comes to moisture over the region.
The GFS wants to bring the surface boundary back north as a warm
front but the new run of the ECMWF brings a shortwave trough
across the northeast zones. No big changes made to the extended
forecast at this point other than to trend PoPs toward climo for
the end of the forecast period. /Kelch

&&

.AVIATION...
06Z TAFS: The region will remain in a stable pattern, especially
near the surface, with a few weak disturbances riding over in the
mid-levels. Abundant low level moisture will keep some low clouds
and fog across the Basin, with localized IFR cigs/vis around MWH.
This is expected to gradually improve toward 12-15Z. Patchier fog
or mist will be possible around the remaining TAF sites, but with
the incoming disturbance we are expecting MVFR/VFR conditions.
Some threat of showers will be found around GEG to COE, PUW and
LWS late overnight into Thursday, with the better chances closer
to the ID panhandle and about the mountains. Winds will pick up
through the day Thursday, with some gusts over 20kts possible.
Late Thursday evening there will the threat of MVFR/IFR cigs
returning over eastern TAF sites.

NOTE: the VIS sensor at EAT is out of service so amendments to
VIS are not scheduled. /J. Cote`

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        52  41  50  27  27  12 /  30  20  70  60  10   0
Coeur d`Alene  51  41  49  29  29  12 /  40  40  80  90  20  10
Pullman        54  43  53  32  32  16 /  30  30  90  90  50  10
Lewiston       56  46  56  38  38  23 /  20  20  60  70  60  20
Colville       50  40  47  22  22   7 /  50  40  70  60  10   0
Sandpoint      46  38  45  26  26   8 /  70  70  80  90  20  10
Kellogg        48  39  45  30  30  12 /  80  70  90 100  50  10
Moses Lake     56  41  56  27  27  12 /  10  20  30  30  10   0
Wenatchee      51  41  51  29  29  13 /  10  30  20  20  10   0
Omak           47  37  46  16  16   3 /  20  20  30  20  10   0

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...Dense Fog Advisory until 7 AM PST early this morning for
Moses Lake Area-Upper Columbia Basin-Waterville Plateau.

&&

$$




000
FXUS66 KOTX 271044
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
244 AM PST THU NOV 27 2014

.SYNOPSIS...
Mild and breezy weather is expected Thanksgiving with areas of
fog in the morning. Snow levels should rise above the mountain
passes. Motorists with plans to travel over the mountain passes
should experience good conditions today through Friday afternoon.
The arrival of a very cold and windy arctic front Friday Night
into Saturday will bring winter driving conditions to the mountain
passes and much cooler weather for the weekend.

&&

.DISCUSSION...

Today through Fri: The biggest changes to the fcst were to
decrease the amnt of pcpn for all non-mountain zones, increase the
winds, and warm temperatures a bit. Though by far the most
eventful part of the fcst will be Fri Nt through the weekend as
we deal with a significant cold front passage that will produce
snow for all elevations, gusty cold north winds and temps as low
as the single digits, we have some relatively mild, but windy
weather to deal with first. Currently behind a cool frontal
passage late yesterday, we`re still anticipating sfc winds to
increase slowly and help to mix out any dense fog now in the Upper
Columbia Basin. We`ve extended the dense fog advsy a few more
hours and will be watched carefully. The good news is that temps
are above freezing, so very slick roads shouldn`t be a big problem
on this important Thanksgiving day travel morning. Today and
Friday all of Ern Wa and N Id will be in a mild pre-arctic cold
front air mass, with well- above normal temps. However, this same
pattern typically favors very gusty winds. This time it`s no
different. Most model guidance shows persistent 850mb winds
(roughly 5k ft above the sfc) from the southwest at 35-45kt.
Expect these winds to begin to increase this morning. Temps will
be mild, even low temps for areas that manage to remain coupled
with these winds aloft (non- valley sites). bz

Friday night through Sunday...The wet but mild weather pattern
will come to an end as an arctic front slides south across the
region bringing much colder and drier air with it. A strong
surface low will slide south across eastern WA and north ID Friday
night, bringing a good chance of precipitation to the eastern half
of the forecast area along with strong gusty southwest winds. Snow
levels will start out around 5k ft Friday evening then come
crashing down overnight. The bulk of the precip will fall as rain
in the valleys. By the time the cold air moves in, the low will be
over central Idaho with showers limited to the southeast zones.
The Camas Prairie may see some low end advisory snowfall but even
this amount is uncertain.

On Saturday the exiting low and building high pressure over
southern BC will set up a strong surface pressure gradient that
will channel northerly winds down the Okanogan Valley and Purcell
Trench and into the basin. This pattern shows the potential for
wind highlights and will continue to be monitored. Saturday
morning temperatures will likely be the high for the day as the
frigid air continues to march south across the area. The rest of
the weekend will continue the cold and dry trend with lows in the
single digits across the northern zones. Valley highs in the 20s
will be common.

Sunday night through Wednesday...The cold temperatures will start
to moderate as northerly winds are replaced by more westerly flow.
Model solutions diverge when it comes to moisture over the region.
The GFS wants to bring the surface boundary back north as a warm
front but the new run of the ECMWF brings a shortwave trough
across the northeast zones. No big changes made to the extended
forecast at this point other than to trend PoPs toward climo for
the end of the forecast period. /Kelch

&&

.AVIATION...
06Z TAFS: The region will remain in a stable pattern, especially
near the surface, with a few weak disturbances riding over in the
mid-levels. Abundant low level moisture will keep some low clouds
and fog across the Basin, with localized IFR cigs/vis around MWH.
This is expected to gradually improve toward 12-15Z. Patchier fog
or mist will be possible around the remaining TAF sites, but with
the incoming disturbance we are expecting MVFR/VFR conditions.
Some threat of showers will be found around GEG to COE, PUW and
LWS late overnight into Thursday, with the better chances closer
to the ID panhandle and about the mountains. Winds will pick up
through the day Thursday, with some gusts over 20kts possible.
Late Thursday evening there will the threat of MVFR/IFR cigs
returning over eastern TAF sites.

NOTE: the VIS sensor at EAT is out of service so amendments to
VIS are not scheduled. /J. Cote`

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        52  41  50  27  27  12 /  30  20  70  60  10   0
Coeur d`Alene  51  41  49  29  29  12 /  40  40  80  90  20  10
Pullman        54  43  53  32  32  16 /  30  30  90  90  50  10
Lewiston       56  46  56  38  38  23 /  20  20  60  70  60  20
Colville       50  40  47  22  22   7 /  50  40  70  60  10   0
Sandpoint      46  38  45  26  26   8 /  70  70  80  90  20  10
Kellogg        48  39  45  30  30  12 /  80  70  90 100  50  10
Moses Lake     56  41  56  27  27  12 /  10  20  30  30  10   0
Wenatchee      51  41  51  29  29  13 /  10  30  20  20  10   0
Omak           47  37  46  16  16   3 /  20  20  30  20  10   0

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...Dense Fog Advisory until 7 AM PST early this morning for
Moses Lake Area-Upper Columbia Basin-Waterville Plateau.

&&

$$





000
FXUS66 KOTX 270636
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
1036 PM PST WED NOV 26 2014

.SYNOPSIS...
Mild and breezy weather is expected tonight and Thanksgiving with
areas of fog. Snow levels should rise above the mountain passes.
Motorists with plans to travel over the mountain passes should
experience good conditions this afternoon through Friday
afternoon. The arrival of a cold front Friday night into Saturday
will bring winter driving conditions to the mountain passes and
much cooler weather for the weekend.


&&

.DISCUSSION...
Evening update: The next couple mid-level disturbances will be
passing tonight and Thursday, shaking things up a little bit. This
will mean some increased threat of precipitation especially
around the mountain areas, and more peripherally around the
eastern Columbia Basin southward.

The broad area of dense fog has begun to decrease in some areas,
such as the Spokane area and northeast mountain valleys. While
some pockets of dense fog are still possible, it is not expected
to be widespread enough and wind are expected to increase some
overnight into Thursday AM. So the dense fog advisory was allowed
to expire in that region. It was however expanded over some of the
Upper Columbia Basin, Waterville Plateau and Moses Lake zones
through the night. HRRR models suggest this too will erode from
the southeast between 06-12Z, with the help of some mixing with
that first mid-level wave. This will be monitored and may
potentially be extended should this decreasing trend not
materialize.

Temperatures have been wonky in some spots this evening. At the
Spokane International Airport the temperature was 36 degrees near
sunset, but at this hour warmed to around 42 degrees, owing to the
fog/lower clouds breaking up some and the winds increased a bit
and mixing some of the warmer air aloft down. The 00Z sounding
showed a modest to strong low level inversion which makes this
warming not too surprising. However overall the confidence in
precise overnight lows is not high. Numbers should remain steady
or fall a degree or two from where they are now though. /J. Cote`

&&

.AVIATION...
06Z TAFS: The region will remain in a stable pattern, especially
near the surface, with a few weak disturbances riding over in the
mid-levels. Abundant low level moisture will keep some low clouds
and fog across the Basin, with localized IFR cigs/vis around MWH.
This is expected to gradually improve toward 12-15Z. Patchier fog
or mist will be possible around the remaining TAF sites, but with
the incoming disturbance we are expecting MVFR/VFR conditions.
Some threat of showers will be found around GEG to COE, PUW and
LWS late overnight into Thursday, with the better chances closer
to the ID panhandle and about the mountains. Winds will pick up
through the day Thursday, with some gusts over 20kts possible.
Late Thursday evening there will the threat of MVFR/IFR cigs
returning over eastern TAF sites.

NOTE: the VIS sensor at EAT is out of service so amendments to
VIS are not scheduled. /J. Cote`


&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        39  49  41  46  27  30 /  30  30  20  70  60  10
Coeur d`Alene  36  47  41  45  29  31 /  30  40  40  80  90  20
Pullman        44  52  43  49  32  34 /  20  30  30  90  90  50
Lewiston       43  55  46  53  38  40 /  10  10  20  60  70  60
Colville       36  45  40  43  22  24 /  60  50  50  70  60  10
Sandpoint      33  45  38  42  26  26 /  70  60  70  80  90  20
Kellogg        37  44  39  41  30  31 /  60  80  60  90 100  50
Moses Lake     38  52  41  51  27  31 /  10  10  20  30  30  10
Wenatchee      39  47  41  48  29  30 /  10  10  30  30  20  10
Omak           34  43  37  41  16  20 /  30  20  20  20  20  10

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...Dense Fog Advisory until 4 AM PST Thursday for Moses Lake Area-
     Upper Columbia Basin-Waterville Plateau.

&&

$$




000
FXUS66 KOTX 270636
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
1036 PM PST WED NOV 26 2014

.SYNOPSIS...
Mild and breezy weather is expected tonight and Thanksgiving with
areas of fog. Snow levels should rise above the mountain passes.
Motorists with plans to travel over the mountain passes should
experience good conditions this afternoon through Friday
afternoon. The arrival of a cold front Friday night into Saturday
will bring winter driving conditions to the mountain passes and
much cooler weather for the weekend.


&&

.DISCUSSION...
Evening update: The next couple mid-level disturbances will be
passing tonight and Thursday, shaking things up a little bit. This
will mean some increased threat of precipitation especially
around the mountain areas, and more peripherally around the
eastern Columbia Basin southward.

The broad area of dense fog has begun to decrease in some areas,
such as the Spokane area and northeast mountain valleys. While
some pockets of dense fog are still possible, it is not expected
to be widespread enough and wind are expected to increase some
overnight into Thursday AM. So the dense fog advisory was allowed
to expire in that region. It was however expanded over some of the
Upper Columbia Basin, Waterville Plateau and Moses Lake zones
through the night. HRRR models suggest this too will erode from
the southeast between 06-12Z, with the help of some mixing with
that first mid-level wave. This will be monitored and may
potentially be extended should this decreasing trend not
materialize.

Temperatures have been wonky in some spots this evening. At the
Spokane International Airport the temperature was 36 degrees near
sunset, but at this hour warmed to around 42 degrees, owing to the
fog/lower clouds breaking up some and the winds increased a bit
and mixing some of the warmer air aloft down. The 00Z sounding
showed a modest to strong low level inversion which makes this
warming not too surprising. However overall the confidence in
precise overnight lows is not high. Numbers should remain steady
or fall a degree or two from where they are now though. /J. Cote`

&&

.AVIATION...
06Z TAFS: The region will remain in a stable pattern, especially
near the surface, with a few weak disturbances riding over in the
mid-levels. Abundant low level moisture will keep some low clouds
and fog across the Basin, with localized IFR cigs/vis around MWH.
This is expected to gradually improve toward 12-15Z. Patchier fog
or mist will be possible around the remaining TAF sites, but with
the incoming disturbance we are expecting MVFR/VFR conditions.
Some threat of showers will be found around GEG to COE, PUW and
LWS late overnight into Thursday, with the better chances closer
to the ID panhandle and about the mountains. Winds will pick up
through the day Thursday, with some gusts over 20kts possible.
Late Thursday evening there will the threat of MVFR/IFR cigs
returning over eastern TAF sites.

NOTE: the VIS sensor at EAT is out of service so amendments to
VIS are not scheduled. /J. Cote`


&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        39  49  41  46  27  30 /  30  30  20  70  60  10
Coeur d`Alene  36  47  41  45  29  31 /  30  40  40  80  90  20
Pullman        44  52  43  49  32  34 /  20  30  30  90  90  50
Lewiston       43  55  46  53  38  40 /  10  10  20  60  70  60
Colville       36  45  40  43  22  24 /  60  50  50  70  60  10
Sandpoint      33  45  38  42  26  26 /  70  60  70  80  90  20
Kellogg        37  44  39  41  30  31 /  60  80  60  90 100  50
Moses Lake     38  52  41  51  27  31 /  10  10  20  30  30  10
Wenatchee      39  47  41  48  29  30 /  10  10  30  30  20  10
Omak           34  43  37  41  16  20 /  30  20  20  20  20  10

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...Dense Fog Advisory until 4 AM PST Thursday for Moses Lake Area-
     Upper Columbia Basin-Waterville Plateau.

&&

$$





000
FXUS66 KSEW 270531
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
930 PM PST WED NOV 26 2014

.SYNOPSIS...A FRONT WILL MOVE EAST ACROSS WESTERN WASHINGTON TONIGHT
FOR MORE RAIN AND WINDY CONDITIONS. RAIN WILL CONTINUE ON
THANKSGIVING DAY AS A COLD FRONT APPROACHES FROM THE NORTH THEN
CROSSES THE AREA ON FRIDAY. A COLD UPPER LEVEL TROUGH WILL MOVE
OVER THE AREA FRIDAY NIGHT AND SATURDAY FOR A CHANCE OF
SHOWERS...POSSIBLY MIXED WITH SNOW. COOLER AND DRY NORTHWEST FLOW
ALOFT AND A SURFACE HIGH OVER BRITISH COLUMBIA WILL COMBINE FOR COOL
DRY WEATHER AND MORE SUNSHINE SUNDAY THROUGH EARLY NEXT WEEK.

&&

.SHORT TERM...CURRENT SATELLITE IMAGERY STILL SHOWS IMPENDING FRONT
OFF THE COAST WITH TIMING ON FROPA REMAINING CONSISTENT...HITTING
THE COAST AROUND OR JUST BEFORE MIDNIGHT AND OVER PUGET SOUND BEFORE
12Z/4 AM. OBSERVED WINDS CONTINUING TO RAMP UP IN ADVANCE OF
APPROACHING FRONT...THOUGH NOT QUITE HITTING ANTICIPATED LOW END
ADVISORY SPEEDS JUST YET. SOME LOCATIONS ON THE NORTH COAST AND
AROUND BLI ARE GETTING CLOSE. NO CHANGE IN EXPECTATION FOR WINDS TO
EASE ONCE THE FRONT PASSES LATE TONIGHT. CURRENT RADAR SHOWS
ACTIVITY ALONG THE CASCADES AND IN ADVANCE OF THE FRONT...LEAVING
PUGET SOUND AND EAST PUGET LOWLANDS MOSTLY DRY FOR NOW. WILL EXPECT
THAT HOLE TO FILL IN AS FRONT DRAWS CLOSER.

PICTURE FOR HOLIDAY WEEKEND REMAINS CONSISTENTLY WET. FOLLOWING
FROPA TONIGHT...MAY CATCH A SLIGHT BREAK BEFORE SECOND FRONT MOVES
SLOWLY OVER THE AREA THURSDAY AND INTO FRIDAY...BRINGING CONTINUED
WET CONDITIONS. RAINFALL AMOUNTS EXPECTED OVER THE NEXT 48 HOURS IN
A PERIOD STRETCHING FROM THIS EVENING THROUGH FRIDAY AFTERNOON RANGE
FROM AROUND 1 TO 2 INCHES OF RAINFALL IN THE LOWLANDS AND 3 TO 6
INCHES OF RAINFALL IN THE HIGHER ELEVATIONS OF THE CASCADES AND
OLYMPICS. THE EXCEPTION BEING UP TO 7 INCHES OF RAINFALL AROUND MT.
BAKER. NEEDLESS TO SAY...THIS AMOUNT OF RAINFALL WILL IMPACT RIVERS
THAT HAVE ALREADY HIT FLOOD STAGE TODAY. EVEN THOUGH THESE RIVERS
ARE TRENDING DOWNWARD WITH REGARD TO FLOW/LEVELS...THIS ADDITIONAL
RAINFALL WILL LIKELY BRING ANOTHER PEAK IN FLOW/LEVELS FRIDAY. FOR
FURTHER DETAILS...REFER TO THE HYDROLOGY SECTION BELOW.

MILD TEMPERATURES ARE EXPECTED TO REMAIN IN PLACE FOR THANKSGIVING
BEFORE CONDITIONS BEGIN TO COOL. AN INTERESTING FORECAST CONUNDRUM
ARISES FRIDAY NIGHT INTO SATURDAY. A DIPPING UPPER LEVEL TROUGH WILL
BRING COLDER AIR TO WESTERN WASHINGTON FRIDAY NIGHT...JUST AT THE
TAIL END OF PRECIP EVENT. GFS AND ECMWF INDICATE THAT THINGS MAY
LINE UP JUST ENOUGH FOR MIXED LOWLAND PRECIP FRIDAY NIGHT WITH
LOWLAND SNOW POSSIBLE SATURDAY. HOWEVER...LATEST RUN OF THE WRF GFS
4KM DOES NOT LOOK AS CONVINCING AS THE OTHER TWO MODELS. INHERITED
FORECAST HAS INCLUDED MENTIONS OF MIXED PRECIP AND SNOW FOR THIS
TIME FRAME AND WILL ALLOW FOR FURTHER REEXAMINATION WITH FUTURE
MODEL RUNS. SMR

.LONG TERM...FROM 410 PM DISCUSSION...A STRONG SURFACE HIGH SETTLING
OVER B.C. ON FRIDAY WILL ALLOW COLD FRASER RIVER VALLEY OUTFLOW TO
DEVELOP...BRINGING MORE COLD AIR DRY S OVER W WA. THE AIR MASS WILL
DRY OUT SATURDAY NIGHT WITH TEMPERATURES DROPPING INTO THE 20S
SUNDAY MORNING. SKIES WILL BE MOSTLY SUNNY. THE FRASER VALLEY
OUTFLOW WILL PROBABLY GENERATE ADVISORY LEVEL NE WINDS OVER WHATCOM
AND SAN JUAN COUNTY FRIDAY NIGHT INTO SATURDAY MORNING.

THE ECMWF HAS LEANED MORE CONSISTENTLY THAN THE GFS IN KEEPING A
COOL DRY PATTERN OVER W WA INTO EARLY NEXT WEEK. THE LATEST ECMWF
NOW KEEPS THE PATTERN DRY THROUGH WEDNESDAY ALTHOUGH THERE ARE
SYSTEM THAT GET CLOSE. THE GFS HAD BEEN MORE AGGRESSIVE IN BRINGING
RAIN UP OVER THE ARE FROM THE S...BUT HAS BACKED AWAY FROM THIS ON
THE 12Z AND 18Z RUNS. IT MAY HAVE BEEN PREMATURE...BUT I HAVE DRIED
OUT EARLY NEXT WEEK. CONFIDENCE IS SHAKY BUT HOPE IT STAYS THAT WAY.
KAM

&&

.HYDROLOGY...FROM 410 PM DISCUSSION...A WARM FRONT HELD HEAVIER
RAINFALL NORTH OF THE WA/BRITISH COLUMBIA BORDER TODAY. THIS IS
ALLOWING MOST RIVERS TO SLOWLY RECEDE ACROSS WRN WA. RAIN AMOUNTS UP
TO 5 INCHES SINCE MONDAY IN PLACES LIKE MOUNT RAINIER AND THE
SKYKOMISH-SNOQUALMIE-TOLT-SNOHOMISH BASIN WILL STILL CAUSE SOME
RESIDUAL FLOODING...MAINLY THROUGH THIS EVENING.

ANOTHER FRONT WILL BRING RENEWED RAINFALL TO WRN WA TONIGHT AND
THURSDAY...LOCALLY HEAVY IN THE MOUNTAINS. THE OLYMPICS AND NORTH
CASCADES WILL RECEIVE THE HEAVIEST RAINFALL WITH 2 TO 4 INCHES OF
RAIN EXPECTED. 1 TO 2 INCHES MAY FALL IN THE CENTRAL CASCADES. THE
SNOW LEVEL WILL BE NEAR 7000 FEET.

A SECONDARY SURGE OF MOISTURE WILL ARRIVE THURSDAY NIGHT INTO
FRIDAY. MODELS VARY MUCH MORE ON THE DISTRIBUTION AND POTENTIAL
RAINFALL AMOUNTS WITH THIS SECOND FRONTAL SYSTEM. IN
GENERAL...HEAVIER RAIN AMOUNTS THURSDAY NIGHT AND FRIDAY SHOULD
OCCUR ALONG S/SW FACING SLOPES OF THE OLYMPICS AND N
CASCADES...ALTHOUGH THE CENTRAL CASCADES COULD ALSO SEE HEAVY
PRECIPITATION BY FRIDAY. ADDITIONAL AMOUNTS OF 2 TO 3 INCHES ARE
POSSIBLE. THIS MEANS THE 36-48 HOUR RAINFALL TOTALS FOR THE OLYMPICS
AND CASCADES MAY REACH 4 TO 7 INCHES WITH LOCALLY HIGHER
AMOUNTS...ESPECIALLY IN THE N CASCADES.

THESE AMOUNTS WILL LIKELY DRIVE SEVERAL RIVERS TO FLOOD...ALTHOUGH
WIDESPREAD MAJOR FLOODING APPEARS UNLIKELY. AT HIGHEST RISK FOR
FLOODING IS THE SKOKOMISH RIVER IN THE OLYMPICS...THE NOOKSACK AND
SKAGIT RIVERS IN THE NORTH...AND THE
STILLAGUAMISH...SNOQUALMIE...AND TOLT ACROSS CENTRAL AREAS. IF THE
HEAVIER RAIN SHIFTS FAR ENOUGH SOUTH THEN FLOODING COULD BE POSSIBLE
ON THE DESCHUTES RIVER AND THE REACH OF THE SKOOKUMCHUCK RIVER NEAR
BUCODA IN THURSTON COUNTY.

A FLOOD WATCH REMAINS IN EFFECT THROUGH FRIDAY...WHICH INCLUDES ALL
THE COUNTIES WITH RIVERS FLOWING OFF THE WEST SLOPES OF THE CASCADES
AND MASON COUNTY FOR THE POSSIBILITY OF A FLOOD ON THE SKOKOMISH.

COLDER AND DRIER WEATHER IS LIKELY THIS WEEKEND...SO RIVERS SHOULD
RECEDE AND THE FLOOD THREAT WILL END FOR THE FORESEEABLE FUTURE.

MERCER

&&

.AVIATION...RAIN IN INCREASE IN COVERAGE ACROSS WESTERN WA TONIGHT
AS A COLD FRONT MOVES INLAND. THE FLOW ALOFT IS WESTERLY. CIGS ARE
MAINLY VFR THIS EVENING BUT SHOULD LOWER INTO MVFR RANGE OVERNIGHT.
GUSTY SOUTH WINDS ARE ALSO EXPECTED WITH THE FRONT...ESPECIALLY
ALONG THE COAST AND NORTH INTERIOR. MOIST WESTERLY FLOW WILL
CONTINUE ON THURSDAY WITH SHOWERS MAINLY AFFECTING THE COAST AND
MOUNTAINS. 33

KSEA...EXPECT RAIN AT TIMES TONIGHT WITH CIGS LOWERING TO MVFR
RANGE. GUSTY SOUTH WINDS 20015G25KT EXPECTED AT THE TERMINAL
THROUGHOUT THE NIGHT. 33

&&

.MARINE...A COLD FRONT WILL SHIFT INLAND TONIGHT WITH INCREASING
SOUTH WINDS OVER THE WATERS. GALE WARNINGS REMAIN IN EFFECT FOR THE
COASTAL WATERS...ENTRANCES TO THE STRAIT OF JUAN DE FUCA AND THE
NORTHERN INLAND WATERS. A GALE WARNING WAS ALSO ISSUED FOR ADMIRALTY
INLET. WINDS WILL EASE OVERNIGHT BUT WILL STILL SEE SMALL CRAFT
ADVISORY WINDS ACROSS THE WATERS. PRESSURE GRADIENTS WILL REMAIN
TIGHT THU NIGHT THROUGH FRI AS ANOTHER COLD FRONT PUSHES SOUTH FROM
B.C. STRONG HIGH PRES OVER INTERIOR B.C. WILL BRING N/NE FRASER
RIVER OUTFLOW WINDS LATE FRI NIGHT INTO SAT. OFFSHORE FLOW WILL
PREVAIL SUN AND MON WITH HIGH PRES EAST OF THE CASCADES. 33

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...FLOOD WATCHES AND WARNINGS IN EFFECT FOR PORTIONS OF
     WESTERN WASHINGTON.
     WIND ADVISORY NORTH COAST...WESTERN WHATCOM...SAN
     JUANS...ADMIRALTY INLET AREA.

PZ...SMALL CRAFT ADVISORY ALL WATERS.
    .SMALL CRAFT ADVISORY GRAYS HARBOR BAR FOR ROUGH BAR.
    .GALE WARNING COASTAL WATERS...ENTRANCES STRAIT OF JUAN DE
     FUCA...NORTHERN INLAND WATERS...ADMIRALTY INLET.

&&

$$

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 270531
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
930 PM PST WED NOV 26 2014

.SYNOPSIS...A FRONT WILL MOVE EAST ACROSS WESTERN WASHINGTON TONIGHT
FOR MORE RAIN AND WINDY CONDITIONS. RAIN WILL CONTINUE ON
THANKSGIVING DAY AS A COLD FRONT APPROACHES FROM THE NORTH THEN
CROSSES THE AREA ON FRIDAY. A COLD UPPER LEVEL TROUGH WILL MOVE
OVER THE AREA FRIDAY NIGHT AND SATURDAY FOR A CHANCE OF
SHOWERS...POSSIBLY MIXED WITH SNOW. COOLER AND DRY NORTHWEST FLOW
ALOFT AND A SURFACE HIGH OVER BRITISH COLUMBIA WILL COMBINE FOR COOL
DRY WEATHER AND MORE SUNSHINE SUNDAY THROUGH EARLY NEXT WEEK.

&&

.SHORT TERM...CURRENT SATELLITE IMAGERY STILL SHOWS IMPENDING FRONT
OFF THE COAST WITH TIMING ON FROPA REMAINING CONSISTENT...HITTING
THE COAST AROUND OR JUST BEFORE MIDNIGHT AND OVER PUGET SOUND BEFORE
12Z/4 AM. OBSERVED WINDS CONTINUING TO RAMP UP IN ADVANCE OF
APPROACHING FRONT...THOUGH NOT QUITE HITTING ANTICIPATED LOW END
ADVISORY SPEEDS JUST YET. SOME LOCATIONS ON THE NORTH COAST AND
AROUND BLI ARE GETTING CLOSE. NO CHANGE IN EXPECTATION FOR WINDS TO
EASE ONCE THE FRONT PASSES LATE TONIGHT. CURRENT RADAR SHOWS
ACTIVITY ALONG THE CASCADES AND IN ADVANCE OF THE FRONT...LEAVING
PUGET SOUND AND EAST PUGET LOWLANDS MOSTLY DRY FOR NOW. WILL EXPECT
THAT HOLE TO FILL IN AS FRONT DRAWS CLOSER.

PICTURE FOR HOLIDAY WEEKEND REMAINS CONSISTENTLY WET. FOLLOWING
FROPA TONIGHT...MAY CATCH A SLIGHT BREAK BEFORE SECOND FRONT MOVES
SLOWLY OVER THE AREA THURSDAY AND INTO FRIDAY...BRINGING CONTINUED
WET CONDITIONS. RAINFALL AMOUNTS EXPECTED OVER THE NEXT 48 HOURS IN
A PERIOD STRETCHING FROM THIS EVENING THROUGH FRIDAY AFTERNOON RANGE
FROM AROUND 1 TO 2 INCHES OF RAINFALL IN THE LOWLANDS AND 3 TO 6
INCHES OF RAINFALL IN THE HIGHER ELEVATIONS OF THE CASCADES AND
OLYMPICS. THE EXCEPTION BEING UP TO 7 INCHES OF RAINFALL AROUND MT.
BAKER. NEEDLESS TO SAY...THIS AMOUNT OF RAINFALL WILL IMPACT RIVERS
THAT HAVE ALREADY HIT FLOOD STAGE TODAY. EVEN THOUGH THESE RIVERS
ARE TRENDING DOWNWARD WITH REGARD TO FLOW/LEVELS...THIS ADDITIONAL
RAINFALL WILL LIKELY BRING ANOTHER PEAK IN FLOW/LEVELS FRIDAY. FOR
FURTHER DETAILS...REFER TO THE HYDROLOGY SECTION BELOW.

MILD TEMPERATURES ARE EXPECTED TO REMAIN IN PLACE FOR THANKSGIVING
BEFORE CONDITIONS BEGIN TO COOL. AN INTERESTING FORECAST CONUNDRUM
ARISES FRIDAY NIGHT INTO SATURDAY. A DIPPING UPPER LEVEL TROUGH WILL
BRING COLDER AIR TO WESTERN WASHINGTON FRIDAY NIGHT...JUST AT THE
TAIL END OF PRECIP EVENT. GFS AND ECMWF INDICATE THAT THINGS MAY
LINE UP JUST ENOUGH FOR MIXED LOWLAND PRECIP FRIDAY NIGHT WITH
LOWLAND SNOW POSSIBLE SATURDAY. HOWEVER...LATEST RUN OF THE WRF GFS
4KM DOES NOT LOOK AS CONVINCING AS THE OTHER TWO MODELS. INHERITED
FORECAST HAS INCLUDED MENTIONS OF MIXED PRECIP AND SNOW FOR THIS
TIME FRAME AND WILL ALLOW FOR FURTHER REEXAMINATION WITH FUTURE
MODEL RUNS. SMR

.LONG TERM...FROM 410 PM DISCUSSION...A STRONG SURFACE HIGH SETTLING
OVER B.C. ON FRIDAY WILL ALLOW COLD FRASER RIVER VALLEY OUTFLOW TO
DEVELOP...BRINGING MORE COLD AIR DRY S OVER W WA. THE AIR MASS WILL
DRY OUT SATURDAY NIGHT WITH TEMPERATURES DROPPING INTO THE 20S
SUNDAY MORNING. SKIES WILL BE MOSTLY SUNNY. THE FRASER VALLEY
OUTFLOW WILL PROBABLY GENERATE ADVISORY LEVEL NE WINDS OVER WHATCOM
AND SAN JUAN COUNTY FRIDAY NIGHT INTO SATURDAY MORNING.

THE ECMWF HAS LEANED MORE CONSISTENTLY THAN THE GFS IN KEEPING A
COOL DRY PATTERN OVER W WA INTO EARLY NEXT WEEK. THE LATEST ECMWF
NOW KEEPS THE PATTERN DRY THROUGH WEDNESDAY ALTHOUGH THERE ARE
SYSTEM THAT GET CLOSE. THE GFS HAD BEEN MORE AGGRESSIVE IN BRINGING
RAIN UP OVER THE ARE FROM THE S...BUT HAS BACKED AWAY FROM THIS ON
THE 12Z AND 18Z RUNS. IT MAY HAVE BEEN PREMATURE...BUT I HAVE DRIED
OUT EARLY NEXT WEEK. CONFIDENCE IS SHAKY BUT HOPE IT STAYS THAT WAY.
KAM

&&

.HYDROLOGY...FROM 410 PM DISCUSSION...A WARM FRONT HELD HEAVIER
RAINFALL NORTH OF THE WA/BRITISH COLUMBIA BORDER TODAY. THIS IS
ALLOWING MOST RIVERS TO SLOWLY RECEDE ACROSS WRN WA. RAIN AMOUNTS UP
TO 5 INCHES SINCE MONDAY IN PLACES LIKE MOUNT RAINIER AND THE
SKYKOMISH-SNOQUALMIE-TOLT-SNOHOMISH BASIN WILL STILL CAUSE SOME
RESIDUAL FLOODING...MAINLY THROUGH THIS EVENING.

ANOTHER FRONT WILL BRING RENEWED RAINFALL TO WRN WA TONIGHT AND
THURSDAY...LOCALLY HEAVY IN THE MOUNTAINS. THE OLYMPICS AND NORTH
CASCADES WILL RECEIVE THE HEAVIEST RAINFALL WITH 2 TO 4 INCHES OF
RAIN EXPECTED. 1 TO 2 INCHES MAY FALL IN THE CENTRAL CASCADES. THE
SNOW LEVEL WILL BE NEAR 7000 FEET.

A SECONDARY SURGE OF MOISTURE WILL ARRIVE THURSDAY NIGHT INTO
FRIDAY. MODELS VARY MUCH MORE ON THE DISTRIBUTION AND POTENTIAL
RAINFALL AMOUNTS WITH THIS SECOND FRONTAL SYSTEM. IN
GENERAL...HEAVIER RAIN AMOUNTS THURSDAY NIGHT AND FRIDAY SHOULD
OCCUR ALONG S/SW FACING SLOPES OF THE OLYMPICS AND N
CASCADES...ALTHOUGH THE CENTRAL CASCADES COULD ALSO SEE HEAVY
PRECIPITATION BY FRIDAY. ADDITIONAL AMOUNTS OF 2 TO 3 INCHES ARE
POSSIBLE. THIS MEANS THE 36-48 HOUR RAINFALL TOTALS FOR THE OLYMPICS
AND CASCADES MAY REACH 4 TO 7 INCHES WITH LOCALLY HIGHER
AMOUNTS...ESPECIALLY IN THE N CASCADES.

THESE AMOUNTS WILL LIKELY DRIVE SEVERAL RIVERS TO FLOOD...ALTHOUGH
WIDESPREAD MAJOR FLOODING APPEARS UNLIKELY. AT HIGHEST RISK FOR
FLOODING IS THE SKOKOMISH RIVER IN THE OLYMPICS...THE NOOKSACK AND
SKAGIT RIVERS IN THE NORTH...AND THE
STILLAGUAMISH...SNOQUALMIE...AND TOLT ACROSS CENTRAL AREAS. IF THE
HEAVIER RAIN SHIFTS FAR ENOUGH SOUTH THEN FLOODING COULD BE POSSIBLE
ON THE DESCHUTES RIVER AND THE REACH OF THE SKOOKUMCHUCK RIVER NEAR
BUCODA IN THURSTON COUNTY.

A FLOOD WATCH REMAINS IN EFFECT THROUGH FRIDAY...WHICH INCLUDES ALL
THE COUNTIES WITH RIVERS FLOWING OFF THE WEST SLOPES OF THE CASCADES
AND MASON COUNTY FOR THE POSSIBILITY OF A FLOOD ON THE SKOKOMISH.

COLDER AND DRIER WEATHER IS LIKELY THIS WEEKEND...SO RIVERS SHOULD
RECEDE AND THE FLOOD THREAT WILL END FOR THE FORESEEABLE FUTURE.

MERCER

&&

.AVIATION...RAIN IN INCREASE IN COVERAGE ACROSS WESTERN WA TONIGHT
AS A COLD FRONT MOVES INLAND. THE FLOW ALOFT IS WESTERLY. CIGS ARE
MAINLY VFR THIS EVENING BUT SHOULD LOWER INTO MVFR RANGE OVERNIGHT.
GUSTY SOUTH WINDS ARE ALSO EXPECTED WITH THE FRONT...ESPECIALLY
ALONG THE COAST AND NORTH INTERIOR. MOIST WESTERLY FLOW WILL
CONTINUE ON THURSDAY WITH SHOWERS MAINLY AFFECTING THE COAST AND
MOUNTAINS. 33

KSEA...EXPECT RAIN AT TIMES TONIGHT WITH CIGS LOWERING TO MVFR
RANGE. GUSTY SOUTH WINDS 20015G25KT EXPECTED AT THE TERMINAL
THROUGHOUT THE NIGHT. 33

&&

.MARINE...A COLD FRONT WILL SHIFT INLAND TONIGHT WITH INCREASING
SOUTH WINDS OVER THE WATERS. GALE WARNINGS REMAIN IN EFFECT FOR THE
COASTAL WATERS...ENTRANCES TO THE STRAIT OF JUAN DE FUCA AND THE
NORTHERN INLAND WATERS. A GALE WARNING WAS ALSO ISSUED FOR ADMIRALTY
INLET. WINDS WILL EASE OVERNIGHT BUT WILL STILL SEE SMALL CRAFT
ADVISORY WINDS ACROSS THE WATERS. PRESSURE GRADIENTS WILL REMAIN
TIGHT THU NIGHT THROUGH FRI AS ANOTHER COLD FRONT PUSHES SOUTH FROM
B.C. STRONG HIGH PRES OVER INTERIOR B.C. WILL BRING N/NE FRASER
RIVER OUTFLOW WINDS LATE FRI NIGHT INTO SAT. OFFSHORE FLOW WILL
PREVAIL SUN AND MON WITH HIGH PRES EAST OF THE CASCADES. 33

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...FLOOD WATCHES AND WARNINGS IN EFFECT FOR PORTIONS OF
     WESTERN WASHINGTON.
     WIND ADVISORY NORTH COAST...WESTERN WHATCOM...SAN
     JUANS...ADMIRALTY INLET AREA.

PZ...SMALL CRAFT ADVISORY ALL WATERS.
    .SMALL CRAFT ADVISORY GRAYS HARBOR BAR FOR ROUGH BAR.
    .GALE WARNING COASTAL WATERS...ENTRANCES STRAIT OF JUAN DE
     FUCA...NORTHERN INLAND WATERS...ADMIRALTY INLET.

&&

$$

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 270531
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
930 PM PST WED NOV 26 2014

.SYNOPSIS...A FRONT WILL MOVE EAST ACROSS WESTERN WASHINGTON TONIGHT
FOR MORE RAIN AND WINDY CONDITIONS. RAIN WILL CONTINUE ON
THANKSGIVING DAY AS A COLD FRONT APPROACHES FROM THE NORTH THEN
CROSSES THE AREA ON FRIDAY. A COLD UPPER LEVEL TROUGH WILL MOVE
OVER THE AREA FRIDAY NIGHT AND SATURDAY FOR A CHANCE OF
SHOWERS...POSSIBLY MIXED WITH SNOW. COOLER AND DRY NORTHWEST FLOW
ALOFT AND A SURFACE HIGH OVER BRITISH COLUMBIA WILL COMBINE FOR COOL
DRY WEATHER AND MORE SUNSHINE SUNDAY THROUGH EARLY NEXT WEEK.

&&

.SHORT TERM...CURRENT SATELLITE IMAGERY STILL SHOWS IMPENDING FRONT
OFF THE COAST WITH TIMING ON FROPA REMAINING CONSISTENT...HITTING
THE COAST AROUND OR JUST BEFORE MIDNIGHT AND OVER PUGET SOUND BEFORE
12Z/4 AM. OBSERVED WINDS CONTINUING TO RAMP UP IN ADVANCE OF
APPROACHING FRONT...THOUGH NOT QUITE HITTING ANTICIPATED LOW END
ADVISORY SPEEDS JUST YET. SOME LOCATIONS ON THE NORTH COAST AND
AROUND BLI ARE GETTING CLOSE. NO CHANGE IN EXPECTATION FOR WINDS TO
EASE ONCE THE FRONT PASSES LATE TONIGHT. CURRENT RADAR SHOWS
ACTIVITY ALONG THE CASCADES AND IN ADVANCE OF THE FRONT...LEAVING
PUGET SOUND AND EAST PUGET LOWLANDS MOSTLY DRY FOR NOW. WILL EXPECT
THAT HOLE TO FILL IN AS FRONT DRAWS CLOSER.

PICTURE FOR HOLIDAY WEEKEND REMAINS CONSISTENTLY WET. FOLLOWING
FROPA TONIGHT...MAY CATCH A SLIGHT BREAK BEFORE SECOND FRONT MOVES
SLOWLY OVER THE AREA THURSDAY AND INTO FRIDAY...BRINGING CONTINUED
WET CONDITIONS. RAINFALL AMOUNTS EXPECTED OVER THE NEXT 48 HOURS IN
A PERIOD STRETCHING FROM THIS EVENING THROUGH FRIDAY AFTERNOON RANGE
FROM AROUND 1 TO 2 INCHES OF RAINFALL IN THE LOWLANDS AND 3 TO 6
INCHES OF RAINFALL IN THE HIGHER ELEVATIONS OF THE CASCADES AND
OLYMPICS. THE EXCEPTION BEING UP TO 7 INCHES OF RAINFALL AROUND MT.
BAKER. NEEDLESS TO SAY...THIS AMOUNT OF RAINFALL WILL IMPACT RIVERS
THAT HAVE ALREADY HIT FLOOD STAGE TODAY. EVEN THOUGH THESE RIVERS
ARE TRENDING DOWNWARD WITH REGARD TO FLOW/LEVELS...THIS ADDITIONAL
RAINFALL WILL LIKELY BRING ANOTHER PEAK IN FLOW/LEVELS FRIDAY. FOR
FURTHER DETAILS...REFER TO THE HYDROLOGY SECTION BELOW.

MILD TEMPERATURES ARE EXPECTED TO REMAIN IN PLACE FOR THANKSGIVING
BEFORE CONDITIONS BEGIN TO COOL. AN INTERESTING FORECAST CONUNDRUM
ARISES FRIDAY NIGHT INTO SATURDAY. A DIPPING UPPER LEVEL TROUGH WILL
BRING COLDER AIR TO WESTERN WASHINGTON FRIDAY NIGHT...JUST AT THE
TAIL END OF PRECIP EVENT. GFS AND ECMWF INDICATE THAT THINGS MAY
LINE UP JUST ENOUGH FOR MIXED LOWLAND PRECIP FRIDAY NIGHT WITH
LOWLAND SNOW POSSIBLE SATURDAY. HOWEVER...LATEST RUN OF THE WRF GFS
4KM DOES NOT LOOK AS CONVINCING AS THE OTHER TWO MODELS. INHERITED
FORECAST HAS INCLUDED MENTIONS OF MIXED PRECIP AND SNOW FOR THIS
TIME FRAME AND WILL ALLOW FOR FURTHER REEXAMINATION WITH FUTURE
MODEL RUNS. SMR

.LONG TERM...FROM 410 PM DISCUSSION...A STRONG SURFACE HIGH SETTLING
OVER B.C. ON FRIDAY WILL ALLOW COLD FRASER RIVER VALLEY OUTFLOW TO
DEVELOP...BRINGING MORE COLD AIR DRY S OVER W WA. THE AIR MASS WILL
DRY OUT SATURDAY NIGHT WITH TEMPERATURES DROPPING INTO THE 20S
SUNDAY MORNING. SKIES WILL BE MOSTLY SUNNY. THE FRASER VALLEY
OUTFLOW WILL PROBABLY GENERATE ADVISORY LEVEL NE WINDS OVER WHATCOM
AND SAN JUAN COUNTY FRIDAY NIGHT INTO SATURDAY MORNING.

THE ECMWF HAS LEANED MORE CONSISTENTLY THAN THE GFS IN KEEPING A
COOL DRY PATTERN OVER W WA INTO EARLY NEXT WEEK. THE LATEST ECMWF
NOW KEEPS THE PATTERN DRY THROUGH WEDNESDAY ALTHOUGH THERE ARE
SYSTEM THAT GET CLOSE. THE GFS HAD BEEN MORE AGGRESSIVE IN BRINGING
RAIN UP OVER THE ARE FROM THE S...BUT HAS BACKED AWAY FROM THIS ON
THE 12Z AND 18Z RUNS. IT MAY HAVE BEEN PREMATURE...BUT I HAVE DRIED
OUT EARLY NEXT WEEK. CONFIDENCE IS SHAKY BUT HOPE IT STAYS THAT WAY.
KAM

&&

.HYDROLOGY...FROM 410 PM DISCUSSION...A WARM FRONT HELD HEAVIER
RAINFALL NORTH OF THE WA/BRITISH COLUMBIA BORDER TODAY. THIS IS
ALLOWING MOST RIVERS TO SLOWLY RECEDE ACROSS WRN WA. RAIN AMOUNTS UP
TO 5 INCHES SINCE MONDAY IN PLACES LIKE MOUNT RAINIER AND THE
SKYKOMISH-SNOQUALMIE-TOLT-SNOHOMISH BASIN WILL STILL CAUSE SOME
RESIDUAL FLOODING...MAINLY THROUGH THIS EVENING.

ANOTHER FRONT WILL BRING RENEWED RAINFALL TO WRN WA TONIGHT AND
THURSDAY...LOCALLY HEAVY IN THE MOUNTAINS. THE OLYMPICS AND NORTH
CASCADES WILL RECEIVE THE HEAVIEST RAINFALL WITH 2 TO 4 INCHES OF
RAIN EXPECTED. 1 TO 2 INCHES MAY FALL IN THE CENTRAL CASCADES. THE
SNOW LEVEL WILL BE NEAR 7000 FEET.

A SECONDARY SURGE OF MOISTURE WILL ARRIVE THURSDAY NIGHT INTO
FRIDAY. MODELS VARY MUCH MORE ON THE DISTRIBUTION AND POTENTIAL
RAINFALL AMOUNTS WITH THIS SECOND FRONTAL SYSTEM. IN
GENERAL...HEAVIER RAIN AMOUNTS THURSDAY NIGHT AND FRIDAY SHOULD
OCCUR ALONG S/SW FACING SLOPES OF THE OLYMPICS AND N
CASCADES...ALTHOUGH THE CENTRAL CASCADES COULD ALSO SEE HEAVY
PRECIPITATION BY FRIDAY. ADDITIONAL AMOUNTS OF 2 TO 3 INCHES ARE
POSSIBLE. THIS MEANS THE 36-48 HOUR RAINFALL TOTALS FOR THE OLYMPICS
AND CASCADES MAY REACH 4 TO 7 INCHES WITH LOCALLY HIGHER
AMOUNTS...ESPECIALLY IN THE N CASCADES.

THESE AMOUNTS WILL LIKELY DRIVE SEVERAL RIVERS TO FLOOD...ALTHOUGH
WIDESPREAD MAJOR FLOODING APPEARS UNLIKELY. AT HIGHEST RISK FOR
FLOODING IS THE SKOKOMISH RIVER IN THE OLYMPICS...THE NOOKSACK AND
SKAGIT RIVERS IN THE NORTH...AND THE
STILLAGUAMISH...SNOQUALMIE...AND TOLT ACROSS CENTRAL AREAS. IF THE
HEAVIER RAIN SHIFTS FAR ENOUGH SOUTH THEN FLOODING COULD BE POSSIBLE
ON THE DESCHUTES RIVER AND THE REACH OF THE SKOOKUMCHUCK RIVER NEAR
BUCODA IN THURSTON COUNTY.

A FLOOD WATCH REMAINS IN EFFECT THROUGH FRIDAY...WHICH INCLUDES ALL
THE COUNTIES WITH RIVERS FLOWING OFF THE WEST SLOPES OF THE CASCADES
AND MASON COUNTY FOR THE POSSIBILITY OF A FLOOD ON THE SKOKOMISH.

COLDER AND DRIER WEATHER IS LIKELY THIS WEEKEND...SO RIVERS SHOULD
RECEDE AND THE FLOOD THREAT WILL END FOR THE FORESEEABLE FUTURE.

MERCER

&&

.AVIATION...RAIN IN INCREASE IN COVERAGE ACROSS WESTERN WA TONIGHT
AS A COLD FRONT MOVES INLAND. THE FLOW ALOFT IS WESTERLY. CIGS ARE
MAINLY VFR THIS EVENING BUT SHOULD LOWER INTO MVFR RANGE OVERNIGHT.
GUSTY SOUTH WINDS ARE ALSO EXPECTED WITH THE FRONT...ESPECIALLY
ALONG THE COAST AND NORTH INTERIOR. MOIST WESTERLY FLOW WILL
CONTINUE ON THURSDAY WITH SHOWERS MAINLY AFFECTING THE COAST AND
MOUNTAINS. 33

KSEA...EXPECT RAIN AT TIMES TONIGHT WITH CIGS LOWERING TO MVFR
RANGE. GUSTY SOUTH WINDS 20015G25KT EXPECTED AT THE TERMINAL
THROUGHOUT THE NIGHT. 33

&&

.MARINE...A COLD FRONT WILL SHIFT INLAND TONIGHT WITH INCREASING
SOUTH WINDS OVER THE WATERS. GALE WARNINGS REMAIN IN EFFECT FOR THE
COASTAL WATERS...ENTRANCES TO THE STRAIT OF JUAN DE FUCA AND THE
NORTHERN INLAND WATERS. A GALE WARNING WAS ALSO ISSUED FOR ADMIRALTY
INLET. WINDS WILL EASE OVERNIGHT BUT WILL STILL SEE SMALL CRAFT
ADVISORY WINDS ACROSS THE WATERS. PRESSURE GRADIENTS WILL REMAIN
TIGHT THU NIGHT THROUGH FRI AS ANOTHER COLD FRONT PUSHES SOUTH FROM
B.C. STRONG HIGH PRES OVER INTERIOR B.C. WILL BRING N/NE FRASER
RIVER OUTFLOW WINDS LATE FRI NIGHT INTO SAT. OFFSHORE FLOW WILL
PREVAIL SUN AND MON WITH HIGH PRES EAST OF THE CASCADES. 33

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...FLOOD WATCHES AND WARNINGS IN EFFECT FOR PORTIONS OF
     WESTERN WASHINGTON.
     WIND ADVISORY NORTH COAST...WESTERN WHATCOM...SAN
     JUANS...ADMIRALTY INLET AREA.

PZ...SMALL CRAFT ADVISORY ALL WATERS.
    .SMALL CRAFT ADVISORY GRAYS HARBOR BAR FOR ROUGH BAR.
    .GALE WARNING COASTAL WATERS...ENTRANCES STRAIT OF JUAN DE
     FUCA...NORTHERN INLAND WATERS...ADMIRALTY INLET.

&&

$$

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 270531
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
930 PM PST WED NOV 26 2014

.SYNOPSIS...A FRONT WILL MOVE EAST ACROSS WESTERN WASHINGTON TONIGHT
FOR MORE RAIN AND WINDY CONDITIONS. RAIN WILL CONTINUE ON
THANKSGIVING DAY AS A COLD FRONT APPROACHES FROM THE NORTH THEN
CROSSES THE AREA ON FRIDAY. A COLD UPPER LEVEL TROUGH WILL MOVE
OVER THE AREA FRIDAY NIGHT AND SATURDAY FOR A CHANCE OF
SHOWERS...POSSIBLY MIXED WITH SNOW. COOLER AND DRY NORTHWEST FLOW
ALOFT AND A SURFACE HIGH OVER BRITISH COLUMBIA WILL COMBINE FOR COOL
DRY WEATHER AND MORE SUNSHINE SUNDAY THROUGH EARLY NEXT WEEK.

&&

.SHORT TERM...CURRENT SATELLITE IMAGERY STILL SHOWS IMPENDING FRONT
OFF THE COAST WITH TIMING ON FROPA REMAINING CONSISTENT...HITTING
THE COAST AROUND OR JUST BEFORE MIDNIGHT AND OVER PUGET SOUND BEFORE
12Z/4 AM. OBSERVED WINDS CONTINUING TO RAMP UP IN ADVANCE OF
APPROACHING FRONT...THOUGH NOT QUITE HITTING ANTICIPATED LOW END
ADVISORY SPEEDS JUST YET. SOME LOCATIONS ON THE NORTH COAST AND
AROUND BLI ARE GETTING CLOSE. NO CHANGE IN EXPECTATION FOR WINDS TO
EASE ONCE THE FRONT PASSES LATE TONIGHT. CURRENT RADAR SHOWS
ACTIVITY ALONG THE CASCADES AND IN ADVANCE OF THE FRONT...LEAVING
PUGET SOUND AND EAST PUGET LOWLANDS MOSTLY DRY FOR NOW. WILL EXPECT
THAT HOLE TO FILL IN AS FRONT DRAWS CLOSER.

PICTURE FOR HOLIDAY WEEKEND REMAINS CONSISTENTLY WET. FOLLOWING
FROPA TONIGHT...MAY CATCH A SLIGHT BREAK BEFORE SECOND FRONT MOVES
SLOWLY OVER THE AREA THURSDAY AND INTO FRIDAY...BRINGING CONTINUED
WET CONDITIONS. RAINFALL AMOUNTS EXPECTED OVER THE NEXT 48 HOURS IN
A PERIOD STRETCHING FROM THIS EVENING THROUGH FRIDAY AFTERNOON RANGE
FROM AROUND 1 TO 2 INCHES OF RAINFALL IN THE LOWLANDS AND 3 TO 6
INCHES OF RAINFALL IN THE HIGHER ELEVATIONS OF THE CASCADES AND
OLYMPICS. THE EXCEPTION BEING UP TO 7 INCHES OF RAINFALL AROUND MT.
BAKER. NEEDLESS TO SAY...THIS AMOUNT OF RAINFALL WILL IMPACT RIVERS
THAT HAVE ALREADY HIT FLOOD STAGE TODAY. EVEN THOUGH THESE RIVERS
ARE TRENDING DOWNWARD WITH REGARD TO FLOW/LEVELS...THIS ADDITIONAL
RAINFALL WILL LIKELY BRING ANOTHER PEAK IN FLOW/LEVELS FRIDAY. FOR
FURTHER DETAILS...REFER TO THE HYDROLOGY SECTION BELOW.

MILD TEMPERATURES ARE EXPECTED TO REMAIN IN PLACE FOR THANKSGIVING
BEFORE CONDITIONS BEGIN TO COOL. AN INTERESTING FORECAST CONUNDRUM
ARISES FRIDAY NIGHT INTO SATURDAY. A DIPPING UPPER LEVEL TROUGH WILL
BRING COLDER AIR TO WESTERN WASHINGTON FRIDAY NIGHT...JUST AT THE
TAIL END OF PRECIP EVENT. GFS AND ECMWF INDICATE THAT THINGS MAY
LINE UP JUST ENOUGH FOR MIXED LOWLAND PRECIP FRIDAY NIGHT WITH
LOWLAND SNOW POSSIBLE SATURDAY. HOWEVER...LATEST RUN OF THE WRF GFS
4KM DOES NOT LOOK AS CONVINCING AS THE OTHER TWO MODELS. INHERITED
FORECAST HAS INCLUDED MENTIONS OF MIXED PRECIP AND SNOW FOR THIS
TIME FRAME AND WILL ALLOW FOR FURTHER REEXAMINATION WITH FUTURE
MODEL RUNS. SMR

.LONG TERM...FROM 410 PM DISCUSSION...A STRONG SURFACE HIGH SETTLING
OVER B.C. ON FRIDAY WILL ALLOW COLD FRASER RIVER VALLEY OUTFLOW TO
DEVELOP...BRINGING MORE COLD AIR DRY S OVER W WA. THE AIR MASS WILL
DRY OUT SATURDAY NIGHT WITH TEMPERATURES DROPPING INTO THE 20S
SUNDAY MORNING. SKIES WILL BE MOSTLY SUNNY. THE FRASER VALLEY
OUTFLOW WILL PROBABLY GENERATE ADVISORY LEVEL NE WINDS OVER WHATCOM
AND SAN JUAN COUNTY FRIDAY NIGHT INTO SATURDAY MORNING.

THE ECMWF HAS LEANED MORE CONSISTENTLY THAN THE GFS IN KEEPING A
COOL DRY PATTERN OVER W WA INTO EARLY NEXT WEEK. THE LATEST ECMWF
NOW KEEPS THE PATTERN DRY THROUGH WEDNESDAY ALTHOUGH THERE ARE
SYSTEM THAT GET CLOSE. THE GFS HAD BEEN MORE AGGRESSIVE IN BRINGING
RAIN UP OVER THE ARE FROM THE S...BUT HAS BACKED AWAY FROM THIS ON
THE 12Z AND 18Z RUNS. IT MAY HAVE BEEN PREMATURE...BUT I HAVE DRIED
OUT EARLY NEXT WEEK. CONFIDENCE IS SHAKY BUT HOPE IT STAYS THAT WAY.
KAM

&&

.HYDROLOGY...FROM 410 PM DISCUSSION...A WARM FRONT HELD HEAVIER
RAINFALL NORTH OF THE WA/BRITISH COLUMBIA BORDER TODAY. THIS IS
ALLOWING MOST RIVERS TO SLOWLY RECEDE ACROSS WRN WA. RAIN AMOUNTS UP
TO 5 INCHES SINCE MONDAY IN PLACES LIKE MOUNT RAINIER AND THE
SKYKOMISH-SNOQUALMIE-TOLT-SNOHOMISH BASIN WILL STILL CAUSE SOME
RESIDUAL FLOODING...MAINLY THROUGH THIS EVENING.

ANOTHER FRONT WILL BRING RENEWED RAINFALL TO WRN WA TONIGHT AND
THURSDAY...LOCALLY HEAVY IN THE MOUNTAINS. THE OLYMPICS AND NORTH
CASCADES WILL RECEIVE THE HEAVIEST RAINFALL WITH 2 TO 4 INCHES OF
RAIN EXPECTED. 1 TO 2 INCHES MAY FALL IN THE CENTRAL CASCADES. THE
SNOW LEVEL WILL BE NEAR 7000 FEET.

A SECONDARY SURGE OF MOISTURE WILL ARRIVE THURSDAY NIGHT INTO
FRIDAY. MODELS VARY MUCH MORE ON THE DISTRIBUTION AND POTENTIAL
RAINFALL AMOUNTS WITH THIS SECOND FRONTAL SYSTEM. IN
GENERAL...HEAVIER RAIN AMOUNTS THURSDAY NIGHT AND FRIDAY SHOULD
OCCUR ALONG S/SW FACING SLOPES OF THE OLYMPICS AND N
CASCADES...ALTHOUGH THE CENTRAL CASCADES COULD ALSO SEE HEAVY
PRECIPITATION BY FRIDAY. ADDITIONAL AMOUNTS OF 2 TO 3 INCHES ARE
POSSIBLE. THIS MEANS THE 36-48 HOUR RAINFALL TOTALS FOR THE OLYMPICS
AND CASCADES MAY REACH 4 TO 7 INCHES WITH LOCALLY HIGHER
AMOUNTS...ESPECIALLY IN THE N CASCADES.

THESE AMOUNTS WILL LIKELY DRIVE SEVERAL RIVERS TO FLOOD...ALTHOUGH
WIDESPREAD MAJOR FLOODING APPEARS UNLIKELY. AT HIGHEST RISK FOR
FLOODING IS THE SKOKOMISH RIVER IN THE OLYMPICS...THE NOOKSACK AND
SKAGIT RIVERS IN THE NORTH...AND THE
STILLAGUAMISH...SNOQUALMIE...AND TOLT ACROSS CENTRAL AREAS. IF THE
HEAVIER RAIN SHIFTS FAR ENOUGH SOUTH THEN FLOODING COULD BE POSSIBLE
ON THE DESCHUTES RIVER AND THE REACH OF THE SKOOKUMCHUCK RIVER NEAR
BUCODA IN THURSTON COUNTY.

A FLOOD WATCH REMAINS IN EFFECT THROUGH FRIDAY...WHICH INCLUDES ALL
THE COUNTIES WITH RIVERS FLOWING OFF THE WEST SLOPES OF THE CASCADES
AND MASON COUNTY FOR THE POSSIBILITY OF A FLOOD ON THE SKOKOMISH.

COLDER AND DRIER WEATHER IS LIKELY THIS WEEKEND...SO RIVERS SHOULD
RECEDE AND THE FLOOD THREAT WILL END FOR THE FORESEEABLE FUTURE.

MERCER

&&

.AVIATION...RAIN IN INCREASE IN COVERAGE ACROSS WESTERN WA TONIGHT
AS A COLD FRONT MOVES INLAND. THE FLOW ALOFT IS WESTERLY. CIGS ARE
MAINLY VFR THIS EVENING BUT SHOULD LOWER INTO MVFR RANGE OVERNIGHT.
GUSTY SOUTH WINDS ARE ALSO EXPECTED WITH THE FRONT...ESPECIALLY
ALONG THE COAST AND NORTH INTERIOR. MOIST WESTERLY FLOW WILL
CONTINUE ON THURSDAY WITH SHOWERS MAINLY AFFECTING THE COAST AND
MOUNTAINS. 33

KSEA...EXPECT RAIN AT TIMES TONIGHT WITH CIGS LOWERING TO MVFR
RANGE. GUSTY SOUTH WINDS 20015G25KT EXPECTED AT THE TERMINAL
THROUGHOUT THE NIGHT. 33

&&

.MARINE...A COLD FRONT WILL SHIFT INLAND TONIGHT WITH INCREASING
SOUTH WINDS OVER THE WATERS. GALE WARNINGS REMAIN IN EFFECT FOR THE
COASTAL WATERS...ENTRANCES TO THE STRAIT OF JUAN DE FUCA AND THE
NORTHERN INLAND WATERS. A GALE WARNING WAS ALSO ISSUED FOR ADMIRALTY
INLET. WINDS WILL EASE OVERNIGHT BUT WILL STILL SEE SMALL CRAFT
ADVISORY WINDS ACROSS THE WATERS. PRESSURE GRADIENTS WILL REMAIN
TIGHT THU NIGHT THROUGH FRI AS ANOTHER COLD FRONT PUSHES SOUTH FROM
B.C. STRONG HIGH PRES OVER INTERIOR B.C. WILL BRING N/NE FRASER
RIVER OUTFLOW WINDS LATE FRI NIGHT INTO SAT. OFFSHORE FLOW WILL
PREVAIL SUN AND MON WITH HIGH PRES EAST OF THE CASCADES. 33

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...FLOOD WATCHES AND WARNINGS IN EFFECT FOR PORTIONS OF
     WESTERN WASHINGTON.
     WIND ADVISORY NORTH COAST...WESTERN WHATCOM...SAN
     JUANS...ADMIRALTY INLET AREA.

PZ...SMALL CRAFT ADVISORY ALL WATERS.
    .SMALL CRAFT ADVISORY GRAYS HARBOR BAR FOR ROUGH BAR.
    .GALE WARNING COASTAL WATERS...ENTRANCES STRAIT OF JUAN DE
     FUCA...NORTHERN INLAND WATERS...ADMIRALTY INLET.

&&

$$

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 270512
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
901 PM PST WED NOV 26 2014

.SYNOPSIS...A WEAK COLD FRONT WILL PUSH SLOWLY INLAND TONIGHT AND
EARLY THU. THE FRONT WILL THEN STALL OVER WESTERN OREGON THU NIGHT
AND FRI...BEFORE ANOTHER STRONGER COLD FRONT WILL MOVE S THROUGH THE
REGION FRI NIGHT USHERING COLDER WEATHER FOR THE WEEKEND. HIGH PRES
OVER THE INTERIOR NW WILL TURN THE FLOW OFFSHORE BY SUN FOR DRY BUT
COLD WEATHER. SUN NIGHT AND MON A SYSTEM COMING UP FROM THE S WILL
ATTEMPT TO SPREAD SOME PRECIPITATION UP OVER THE COLD AIR MASS LEFT
OVER FROM THE WEEKEND.
&&

.UPDATE...NWS DOPPLER RADAR DEPICTS PRECIPITATION BEGINNING TO
SPREAD ONSHORE ACROSS THE REGION...THROUGH OBSERVATIONS
INDICATE THAT ACCUMULATIONS HAVE BEEN LIMITED THUS FAR...GENERALLY
ONLY A TRACE OR FEW HUNDREDTHS OF AN INCH AT BEST. FORECAST REMAINS
GENERALLY ON TRACK...BUT INCREASED POPS A BIT ALONG THE CENTRAL
OREGON COAST THROUGH THE NEAR TERM PER RADAR AND SATELLITE TRENDS.
THE FRONTAL BAND OF PRECIPITATION APPEARS SOMEWHAT DISJOINTED IN
APPEARANCE AND EXPECT RAINFALL TO BE INITIALLY LIGHT FOR THE NEXT FEW
HOURS...BEFORE INCREASING LATER TONIGHT THROUGH EARLY THU. LATEST
MODEL GUIDANCE SUGGESTS THAT THE SYSTEM MAY SPLIT N AND S...LEAVING
MANY PORTIONS OF THE AREA WITH ONLY OCCASIONAL LIGHT RAIN FROM MIDDAY
THU THROUGH THU EVENING. ALSO NUDGED FORECAST LOW TEMPERATURES FOR
TONIGHT A FEW DEGREES LOWER IN LINE WITH OBSERVATIONS AND GUIDANCE.
CULLEN
&&

.PREVIOUS DISCUSSION... /ISSUED 200 PM PST WED NOV 26 2014/

SHORT TERM...A WEAK COLD FRONT WAS OFFSHORE WED AFTERNOON...WITH
LAYERED CLOUDS SPREAD OUT AHEAD OF THE FRONT OVER THE PACIFIC NW. AS
THE UPPER RIDGE OVER THE REGION SHIFTS E TONIGHT AND THU THE FLOW
WILL TURN MORE TO THE SW...WITH THE FRONT SLOWLY PUSHING INLAND.
MODEL SOUNDINGS AGREE IN SHOWING MOISTURE INITIALLY IN THEMID AND
HIGH LEVELS...ABOVE 700MB. BY LATE TONIGHT THOUGH MOISTURE BEGINS TO
SPREAD IN IN THE LOWER LEVELS. DYNAMICS WITH THIS FRONT HOWEVER ON
THE WEAK SIDE...SO WILL BE SLOW TO INCREASE POPS OVERNIGHT INLAND
AREAS...WHILE THE COAST AND COAST RANGE WILL BENEFIT FROM AN
INCREASING LOW LEVEL SSW FLOW. WITH CLOUDS LIMITING RADIATIONAL
COOLING TONIGHT AND MUCH OF THE AREA STILL IN THE WARM SECTOR...
SHOULD BE ANOTHER UNSEASONABLY MILD NIGHT. THU THE FRONT APPEARS TO
STALL OVER THE REGION AS THE LOW OFFSHORE DIGS IN A BIT MORE. WITH
BAROCLINIC ZONE STALLED AND LOW LEVEL FLOW A LITTLE MORE ONSHORE
WILL TAKE POPS BACK UP TO LIKELY TO CATEGORICAL FOR MOST OF THE
REGION. ALTHOUGH THERE IS ONLY MODEST COOLING TO AIR MASS WITH THE
FRONT...CLOUDS AND EXPECTED OCCASIONAL LIGHT RAIN WILL LIMIT HIGH
TEMPS TO THE 50S MOST LOW ELEVATION AREAS.

LATE THU NIGHT...AND ESP FRI BETTER MOISTURE ARRIVES AS A NORTHERN
STREAM SHORT WAVE DROPS DOWN THROUGH BC WITH A TRUE COLD FRONT
DROPPING DOWN THE COAST AHEAD OF IT. MOIST ISENTROPIC LIFT IN THE
LOWER LEVELS IMPROVES AHEAD OF THE COLD FRONT AS WELL...BEST
DEPICTED IN MODEL 290K ISENTROPIC FIELDS. AS SUCH...POTENTIAL FOR
RAIN PICKS UP CONSIDERABLY BY FRI.

MODELS IN RELATIVELY GOOD AGREEMENT IN DEPICTING THE WESTERN
CANADIAN TROUGH DIGGING DOWN INTO THE PACIFIC NW STATES FRI NIGHT
AND SAT. ALL MODELS AT THIS POINT SHOWING A VIGOROUS CONTINENTAL
TYPE COLD FRONT MOVING S THROUGH SW WA AND NW OREGON FRI NIGHT.
PATTERN IS REMINISCENT OF A COLD FRONT FROM BACK ON 19 NOVEMBER 2003
THAT BROUGHT LOW ELEVATION SNOW TO INTERIOR N PARTS OF THE FORECAST
AREA. KEYS TO DOING SOMETHING SIMILAR RELY ON SOME OF THE
PRECIPITATION FALLING OVER AND BEHIND THE FRONT AS WELL AS STRONG
FRONTOGENETIC FORCING TO ALLOW FOR DYNAMIC COOLING. MODEL SOUNDINGS
AT THIS POINT INDICATE SNOW LEVEL FALLING RAPIDLY BEHIND THE FRONT
FRI NIGHT SUGGESTING AT LEAST A MIX OF RAIN AND SNOW POSSIBLE DOWN
TO FAIRLY LOW LEVELS. WHETHER IT WOULD BE COLD ENOUGH TO MIX SNOW AT
LOWEST ELEVATIONS IS ANYBODYS GUESS AT THIS POINT...BUT GIVEN THE
AGREEMENT IN MODELS AT THIS POINT WILL CARRY A MENTION OF MIXED RAIN
AND SNOW POSSIBLE FOR THE N PART OF THE AREA FRI NIGHT. SAT SEES A
RATHER COLD AIR MASS SETTLING IN OVER THE REGION BEHIND THE FRONT...
WITH A LINGERING CHANCE FOR SHOWERS...POTENTIALLY MIXED WITH SNOW IN
THE N...AS THE UPPER TROUGH MOVES THROUGH.

LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY...MOST GUIDANCE
SUGGESTS THE UPPER TROUGH AXIS RESPONSIBLE FOR SATURDAYS MIXED
RAIN/SNOW SHOWERS WILL BE MOVING ACROSS THE CASCADES SAT NIGHT...
WITH ANY LINGERING SNOW SHOWERS COMING TO END OVERNIGHT. EXPECT SOME
CLEARING SAT NIGHT AS COLD HIGH PRESSURE BUILDS DOWN FROM BRITISH
COLUMBIA...WITH LOW TEMPS LIKELY GETTING WELL INTO THE 20S FOR MOST
SPOTS. WITH HIGH PRESSURE STRENGTHENING EAST OF THE CASCADES...
EXPECT STRONG EAST WINDS TO RAMP UP THROUGH THE GORGE SUNDAY MORNING
AND PERSIST FOR MUCH OF THE PERIOD THROUGH WEDNESDAY...WITH BREEZY
CONDITIONS SPILLING INTO THE PORTLAND/VANCOUVER METRO. MONDAY MAY BE
A BRIEF BREAK FROM THE WINDS AS A SYSTEM PASSES BY TO OUR NORTH.

MEANWHILE...A DISTURBANCE FROM THE ALEUTIANS IS EXPECTED TO CUT OFF
FROM THE MAIN PACIFIC JET AND SETTLE OFF THE CALIFORNIA COAST BY
SUNDAY...WHERE IT WILL LIKELY LINGER FOR A COUPLE DAYS. THERE IS A
CHANCE THIS SYSTEM COULD COME CLOSE ENOUGH TO SPREAD SOME PRECIP
NORTHWARD INTO OUR FORECAST AREA SUN NIGHT OR MON. THE 12Z GFS AND
CANADIAN MODELS ARE MORE AGGRESSIVE WITH THIS THAN THE ECMWF. IF
THIS OCCURS...THERE MAY BE SOME LIGHT FREEZING RAIN IN PORTIONS OF
THE WILLAMETTE VALLEY WITH SOME SNOW OR LIGHT FREEZING RAIN IN THE
GORGE. CUTOFF LOWS SUCH AS THIS ONE ARE NOTORIOUSLY DIFFICULT TO
FORECAST...AS MODELS STRUGGLE WITH THEM IN THE EXTENDED FORECAST
PERIOD. WHERE THIS UPPER LOW GOES WILL DICTATE THE WEATHER THROUGH
MIDWEEK...BUT TEMPS ARE EXPECTED TO SLOWLY MODERATE TUESDAY AND
WEDNESDAY.  WEAGLE
&&

.AVIATION...VFR CONTINUES FOR NOW EXCEPT FOR KAST WHERE PASSING
RAIN BANDS HAVE BRIEFLY LOWERED THE CIGS TO AROUND 029. EXPECT THE
OVERALL CONDITIONS TO CONTINUE DETERIORATING OVER THE NEXT SEVERAL
HOURS AS THE OFFSHORE COLD FRONT CONTINUES ITS APPROACH. EVEN THEN
LATEST GUIDANCE IS NOT TERRIBLY PESSIMISTIC WITH FLIGHT
CONDITIONS AHEAD OF AND WITH THE FRONTAL PASSAGE. RADAR BACKS THIS
UP AS RETURNS ARE FAIRLY DISJOINTED IMPLYING A LACK OF
ORGANIZATION. AS SUCH...WILL CONTINUE THE PREVIOUS PACKAGES INTENT
OF SHOWING A LOWER AND WEAKLY CONVECTIVE DECK AFTER THE FRONT AND
LASTING THROUGH MOST OF THURSDAY. THIS APPEARS TO RESULT IN IFR
CIGS AT THE COAST AND MVFR CIGS AROUND 020 INLAND.

KPDX AND APPROACHES...VFR CONDITIONS TO PREVAIL THROUGH AT LEAST
12Z THU WITH VISUAL APPROACHED BECOMING IMPACTED SHORTLY
THEREAFTER AS THE DECK LOWERS BEYOND 040. WILL LIKELY SEE CIGS
BOTTOM OUT AROUND 020 CLOSER TO 18Z WITH LITTLE LIFT FOR THE
REMAINDER OF THE LOCAL CALENDAR DAY. /JBONK

&&

.MARINE...WINDS HAVE BEEN UNDER PERFORMING THUS FAR TONIGHT WITH
THE HRRR MODEL HAVING AS GOOD OF A HANDLE AS ANYTHING. DO EXPECT
COASTAL JET ENHANCEMENT AS THE FRONT NEARS TONIGHT BUT LAST FEW
RUNS OF THE HRRR ONLY INDICATE A VERY MARGINAL GALE GUST SCENARIO
FROM ABOUT 15 NM OUT TOWARDS SHORE. BEST WINDS WILL STAY WELL
ELEVATED OFF THE WATER SURFACE AS BROAD ATMOSPHERIC LIFT IS NOT
SUPPORTING THE HIGHER SPEEDS GETTING MIXED TO THE SURFACE. WILL
MAINTAIN THE GALE WARNING SINCE IT HAS ALREADY BEEN ISSUED.

BEHIND THE FRONT...HIGH-END SMALL CRAFT ADVISORY SPEEDS PERSIST
THU MORNING. LATEST MODEL RUNS SHOW 20-25 KT NW-N WIND DEVELOPING
OVER THE N WATERS FRI EVENING THEN SPREADING FURTHER S OVERNIGHT
AS A STRONG COLD FRONT DROPS SOUTH OUT OF CANADA. THE WIND TURNS
OFFSHORE SAT WITH POTENTIAL GUSTS 20 TO 30 KT NEAR GAPS IN THE
COASTAL TERRAIN. WIND SPEEDS RELAX SUN.

SEAS EXPECTED TO BUILD TO 10 FT THIS EVENING THEN REMAIN AT OR
ABOVE 10 FT THROUGH AT LEAST SAT MORNING. WAVE HEIGHTS DROP OFF
SAT AFTERNOON AS OFFSHORE FLOW DEVELOPS. JBONK/WEISHAAR

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...GALE WARNING UNTIL 4 AM PST THURSDAY FOR COASTAL WATERS FROM
     CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 4 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 270512
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
901 PM PST WED NOV 26 2014

.SYNOPSIS...A WEAK COLD FRONT WILL PUSH SLOWLY INLAND TONIGHT AND
EARLY THU. THE FRONT WILL THEN STALL OVER WESTERN OREGON THU NIGHT
AND FRI...BEFORE ANOTHER STRONGER COLD FRONT WILL MOVE S THROUGH THE
REGION FRI NIGHT USHERING COLDER WEATHER FOR THE WEEKEND. HIGH PRES
OVER THE INTERIOR NW WILL TURN THE FLOW OFFSHORE BY SUN FOR DRY BUT
COLD WEATHER. SUN NIGHT AND MON A SYSTEM COMING UP FROM THE S WILL
ATTEMPT TO SPREAD SOME PRECIPITATION UP OVER THE COLD AIR MASS LEFT
OVER FROM THE WEEKEND.
&&

.UPDATE...NWS DOPPLER RADAR DEPICTS PRECIPITATION BEGINNING TO
SPREAD ONSHORE ACROSS THE REGION...THROUGH OBSERVATIONS
INDICATE THAT ACCUMULATIONS HAVE BEEN LIMITED THUS FAR...GENERALLY
ONLY A TRACE OR FEW HUNDREDTHS OF AN INCH AT BEST. FORECAST REMAINS
GENERALLY ON TRACK...BUT INCREASED POPS A BIT ALONG THE CENTRAL
OREGON COAST THROUGH THE NEAR TERM PER RADAR AND SATELLITE TRENDS.
THE FRONTAL BAND OF PRECIPITATION APPEARS SOMEWHAT DISJOINTED IN
APPEARANCE AND EXPECT RAINFALL TO BE INITIALLY LIGHT FOR THE NEXT FEW
HOURS...BEFORE INCREASING LATER TONIGHT THROUGH EARLY THU. LATEST
MODEL GUIDANCE SUGGESTS THAT THE SYSTEM MAY SPLIT N AND S...LEAVING
MANY PORTIONS OF THE AREA WITH ONLY OCCASIONAL LIGHT RAIN FROM MIDDAY
THU THROUGH THU EVENING. ALSO NUDGED FORECAST LOW TEMPERATURES FOR
TONIGHT A FEW DEGREES LOWER IN LINE WITH OBSERVATIONS AND GUIDANCE.
CULLEN
&&

.PREVIOUS DISCUSSION... /ISSUED 200 PM PST WED NOV 26 2014/

SHORT TERM...A WEAK COLD FRONT WAS OFFSHORE WED AFTERNOON...WITH
LAYERED CLOUDS SPREAD OUT AHEAD OF THE FRONT OVER THE PACIFIC NW. AS
THE UPPER RIDGE OVER THE REGION SHIFTS E TONIGHT AND THU THE FLOW
WILL TURN MORE TO THE SW...WITH THE FRONT SLOWLY PUSHING INLAND.
MODEL SOUNDINGS AGREE IN SHOWING MOISTURE INITIALLY IN THEMID AND
HIGH LEVELS...ABOVE 700MB. BY LATE TONIGHT THOUGH MOISTURE BEGINS TO
SPREAD IN IN THE LOWER LEVELS. DYNAMICS WITH THIS FRONT HOWEVER ON
THE WEAK SIDE...SO WILL BE SLOW TO INCREASE POPS OVERNIGHT INLAND
AREAS...WHILE THE COAST AND COAST RANGE WILL BENEFIT FROM AN
INCREASING LOW LEVEL SSW FLOW. WITH CLOUDS LIMITING RADIATIONAL
COOLING TONIGHT AND MUCH OF THE AREA STILL IN THE WARM SECTOR...
SHOULD BE ANOTHER UNSEASONABLY MILD NIGHT. THU THE FRONT APPEARS TO
STALL OVER THE REGION AS THE LOW OFFSHORE DIGS IN A BIT MORE. WITH
BAROCLINIC ZONE STALLED AND LOW LEVEL FLOW A LITTLE MORE ONSHORE
WILL TAKE POPS BACK UP TO LIKELY TO CATEGORICAL FOR MOST OF THE
REGION. ALTHOUGH THERE IS ONLY MODEST COOLING TO AIR MASS WITH THE
FRONT...CLOUDS AND EXPECTED OCCASIONAL LIGHT RAIN WILL LIMIT HIGH
TEMPS TO THE 50S MOST LOW ELEVATION AREAS.

LATE THU NIGHT...AND ESP FRI BETTER MOISTURE ARRIVES AS A NORTHERN
STREAM SHORT WAVE DROPS DOWN THROUGH BC WITH A TRUE COLD FRONT
DROPPING DOWN THE COAST AHEAD OF IT. MOIST ISENTROPIC LIFT IN THE
LOWER LEVELS IMPROVES AHEAD OF THE COLD FRONT AS WELL...BEST
DEPICTED IN MODEL 290K ISENTROPIC FIELDS. AS SUCH...POTENTIAL FOR
RAIN PICKS UP CONSIDERABLY BY FRI.

MODELS IN RELATIVELY GOOD AGREEMENT IN DEPICTING THE WESTERN
CANADIAN TROUGH DIGGING DOWN INTO THE PACIFIC NW STATES FRI NIGHT
AND SAT. ALL MODELS AT THIS POINT SHOWING A VIGOROUS CONTINENTAL
TYPE COLD FRONT MOVING S THROUGH SW WA AND NW OREGON FRI NIGHT.
PATTERN IS REMINISCENT OF A COLD FRONT FROM BACK ON 19 NOVEMBER 2003
THAT BROUGHT LOW ELEVATION SNOW TO INTERIOR N PARTS OF THE FORECAST
AREA. KEYS TO DOING SOMETHING SIMILAR RELY ON SOME OF THE
PRECIPITATION FALLING OVER AND BEHIND THE FRONT AS WELL AS STRONG
FRONTOGENETIC FORCING TO ALLOW FOR DYNAMIC COOLING. MODEL SOUNDINGS
AT THIS POINT INDICATE SNOW LEVEL FALLING RAPIDLY BEHIND THE FRONT
FRI NIGHT SUGGESTING AT LEAST A MIX OF RAIN AND SNOW POSSIBLE DOWN
TO FAIRLY LOW LEVELS. WHETHER IT WOULD BE COLD ENOUGH TO MIX SNOW AT
LOWEST ELEVATIONS IS ANYBODYS GUESS AT THIS POINT...BUT GIVEN THE
AGREEMENT IN MODELS AT THIS POINT WILL CARRY A MENTION OF MIXED RAIN
AND SNOW POSSIBLE FOR THE N PART OF THE AREA FRI NIGHT. SAT SEES A
RATHER COLD AIR MASS SETTLING IN OVER THE REGION BEHIND THE FRONT...
WITH A LINGERING CHANCE FOR SHOWERS...POTENTIALLY MIXED WITH SNOW IN
THE N...AS THE UPPER TROUGH MOVES THROUGH.

LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY...MOST GUIDANCE
SUGGESTS THE UPPER TROUGH AXIS RESPONSIBLE FOR SATURDAYS MIXED
RAIN/SNOW SHOWERS WILL BE MOVING ACROSS THE CASCADES SAT NIGHT...
WITH ANY LINGERING SNOW SHOWERS COMING TO END OVERNIGHT. EXPECT SOME
CLEARING SAT NIGHT AS COLD HIGH PRESSURE BUILDS DOWN FROM BRITISH
COLUMBIA...WITH LOW TEMPS LIKELY GETTING WELL INTO THE 20S FOR MOST
SPOTS. WITH HIGH PRESSURE STRENGTHENING EAST OF THE CASCADES...
EXPECT STRONG EAST WINDS TO RAMP UP THROUGH THE GORGE SUNDAY MORNING
AND PERSIST FOR MUCH OF THE PERIOD THROUGH WEDNESDAY...WITH BREEZY
CONDITIONS SPILLING INTO THE PORTLAND/VANCOUVER METRO. MONDAY MAY BE
A BRIEF BREAK FROM THE WINDS AS A SYSTEM PASSES BY TO OUR NORTH.

MEANWHILE...A DISTURBANCE FROM THE ALEUTIANS IS EXPECTED TO CUT OFF
FROM THE MAIN PACIFIC JET AND SETTLE OFF THE CALIFORNIA COAST BY
SUNDAY...WHERE IT WILL LIKELY LINGER FOR A COUPLE DAYS. THERE IS A
CHANCE THIS SYSTEM COULD COME CLOSE ENOUGH TO SPREAD SOME PRECIP
NORTHWARD INTO OUR FORECAST AREA SUN NIGHT OR MON. THE 12Z GFS AND
CANADIAN MODELS ARE MORE AGGRESSIVE WITH THIS THAN THE ECMWF. IF
THIS OCCURS...THERE MAY BE SOME LIGHT FREEZING RAIN IN PORTIONS OF
THE WILLAMETTE VALLEY WITH SOME SNOW OR LIGHT FREEZING RAIN IN THE
GORGE. CUTOFF LOWS SUCH AS THIS ONE ARE NOTORIOUSLY DIFFICULT TO
FORECAST...AS MODELS STRUGGLE WITH THEM IN THE EXTENDED FORECAST
PERIOD. WHERE THIS UPPER LOW GOES WILL DICTATE THE WEATHER THROUGH
MIDWEEK...BUT TEMPS ARE EXPECTED TO SLOWLY MODERATE TUESDAY AND
WEDNESDAY.  WEAGLE
&&

.AVIATION...VFR CONTINUES FOR NOW EXCEPT FOR KAST WHERE PASSING
RAIN BANDS HAVE BRIEFLY LOWERED THE CIGS TO AROUND 029. EXPECT THE
OVERALL CONDITIONS TO CONTINUE DETERIORATING OVER THE NEXT SEVERAL
HOURS AS THE OFFSHORE COLD FRONT CONTINUES ITS APPROACH. EVEN THEN
LATEST GUIDANCE IS NOT TERRIBLY PESSIMISTIC WITH FLIGHT
CONDITIONS AHEAD OF AND WITH THE FRONTAL PASSAGE. RADAR BACKS THIS
UP AS RETURNS ARE FAIRLY DISJOINTED IMPLYING A LACK OF
ORGANIZATION. AS SUCH...WILL CONTINUE THE PREVIOUS PACKAGES INTENT
OF SHOWING A LOWER AND WEAKLY CONVECTIVE DECK AFTER THE FRONT AND
LASTING THROUGH MOST OF THURSDAY. THIS APPEARS TO RESULT IN IFR
CIGS AT THE COAST AND MVFR CIGS AROUND 020 INLAND.

KPDX AND APPROACHES...VFR CONDITIONS TO PREVAIL THROUGH AT LEAST
12Z THU WITH VISUAL APPROACHED BECOMING IMPACTED SHORTLY
THEREAFTER AS THE DECK LOWERS BEYOND 040. WILL LIKELY SEE CIGS
BOTTOM OUT AROUND 020 CLOSER TO 18Z WITH LITTLE LIFT FOR THE
REMAINDER OF THE LOCAL CALENDAR DAY. /JBONK

&&

.MARINE...WINDS HAVE BEEN UNDER PERFORMING THUS FAR TONIGHT WITH
THE HRRR MODEL HAVING AS GOOD OF A HANDLE AS ANYTHING. DO EXPECT
COASTAL JET ENHANCEMENT AS THE FRONT NEARS TONIGHT BUT LAST FEW
RUNS OF THE HRRR ONLY INDICATE A VERY MARGINAL GALE GUST SCENARIO
FROM ABOUT 15 NM OUT TOWARDS SHORE. BEST WINDS WILL STAY WELL
ELEVATED OFF THE WATER SURFACE AS BROAD ATMOSPHERIC LIFT IS NOT
SUPPORTING THE HIGHER SPEEDS GETTING MIXED TO THE SURFACE. WILL
MAINTAIN THE GALE WARNING SINCE IT HAS ALREADY BEEN ISSUED.

BEHIND THE FRONT...HIGH-END SMALL CRAFT ADVISORY SPEEDS PERSIST
THU MORNING. LATEST MODEL RUNS SHOW 20-25 KT NW-N WIND DEVELOPING
OVER THE N WATERS FRI EVENING THEN SPREADING FURTHER S OVERNIGHT
AS A STRONG COLD FRONT DROPS SOUTH OUT OF CANADA. THE WIND TURNS
OFFSHORE SAT WITH POTENTIAL GUSTS 20 TO 30 KT NEAR GAPS IN THE
COASTAL TERRAIN. WIND SPEEDS RELAX SUN.

SEAS EXPECTED TO BUILD TO 10 FT THIS EVENING THEN REMAIN AT OR
ABOVE 10 FT THROUGH AT LEAST SAT MORNING. WAVE HEIGHTS DROP OFF
SAT AFTERNOON AS OFFSHORE FLOW DEVELOPS. JBONK/WEISHAAR

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...GALE WARNING UNTIL 4 AM PST THURSDAY FOR COASTAL WATERS FROM
     CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 4 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 270512
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
901 PM PST WED NOV 26 2014

.SYNOPSIS...A WEAK COLD FRONT WILL PUSH SLOWLY INLAND TONIGHT AND
EARLY THU. THE FRONT WILL THEN STALL OVER WESTERN OREGON THU NIGHT
AND FRI...BEFORE ANOTHER STRONGER COLD FRONT WILL MOVE S THROUGH THE
REGION FRI NIGHT USHERING COLDER WEATHER FOR THE WEEKEND. HIGH PRES
OVER THE INTERIOR NW WILL TURN THE FLOW OFFSHORE BY SUN FOR DRY BUT
COLD WEATHER. SUN NIGHT AND MON A SYSTEM COMING UP FROM THE S WILL
ATTEMPT TO SPREAD SOME PRECIPITATION UP OVER THE COLD AIR MASS LEFT
OVER FROM THE WEEKEND.
&&

.UPDATE...NWS DOPPLER RADAR DEPICTS PRECIPITATION BEGINNING TO
SPREAD ONSHORE ACROSS THE REGION...THROUGH OBSERVATIONS
INDICATE THAT ACCUMULATIONS HAVE BEEN LIMITED THUS FAR...GENERALLY
ONLY A TRACE OR FEW HUNDREDTHS OF AN INCH AT BEST. FORECAST REMAINS
GENERALLY ON TRACK...BUT INCREASED POPS A BIT ALONG THE CENTRAL
OREGON COAST THROUGH THE NEAR TERM PER RADAR AND SATELLITE TRENDS.
THE FRONTAL BAND OF PRECIPITATION APPEARS SOMEWHAT DISJOINTED IN
APPEARANCE AND EXPECT RAINFALL TO BE INITIALLY LIGHT FOR THE NEXT FEW
HOURS...BEFORE INCREASING LATER TONIGHT THROUGH EARLY THU. LATEST
MODEL GUIDANCE SUGGESTS THAT THE SYSTEM MAY SPLIT N AND S...LEAVING
MANY PORTIONS OF THE AREA WITH ONLY OCCASIONAL LIGHT RAIN FROM MIDDAY
THU THROUGH THU EVENING. ALSO NUDGED FORECAST LOW TEMPERATURES FOR
TONIGHT A FEW DEGREES LOWER IN LINE WITH OBSERVATIONS AND GUIDANCE.
CULLEN
&&

.PREVIOUS DISCUSSION... /ISSUED 200 PM PST WED NOV 26 2014/

SHORT TERM...A WEAK COLD FRONT WAS OFFSHORE WED AFTERNOON...WITH
LAYERED CLOUDS SPREAD OUT AHEAD OF THE FRONT OVER THE PACIFIC NW. AS
THE UPPER RIDGE OVER THE REGION SHIFTS E TONIGHT AND THU THE FLOW
WILL TURN MORE TO THE SW...WITH THE FRONT SLOWLY PUSHING INLAND.
MODEL SOUNDINGS AGREE IN SHOWING MOISTURE INITIALLY IN THEMID AND
HIGH LEVELS...ABOVE 700MB. BY LATE TONIGHT THOUGH MOISTURE BEGINS TO
SPREAD IN IN THE LOWER LEVELS. DYNAMICS WITH THIS FRONT HOWEVER ON
THE WEAK SIDE...SO WILL BE SLOW TO INCREASE POPS OVERNIGHT INLAND
AREAS...WHILE THE COAST AND COAST RANGE WILL BENEFIT FROM AN
INCREASING LOW LEVEL SSW FLOW. WITH CLOUDS LIMITING RADIATIONAL
COOLING TONIGHT AND MUCH OF THE AREA STILL IN THE WARM SECTOR...
SHOULD BE ANOTHER UNSEASONABLY MILD NIGHT. THU THE FRONT APPEARS TO
STALL OVER THE REGION AS THE LOW OFFSHORE DIGS IN A BIT MORE. WITH
BAROCLINIC ZONE STALLED AND LOW LEVEL FLOW A LITTLE MORE ONSHORE
WILL TAKE POPS BACK UP TO LIKELY TO CATEGORICAL FOR MOST OF THE
REGION. ALTHOUGH THERE IS ONLY MODEST COOLING TO AIR MASS WITH THE
FRONT...CLOUDS AND EXPECTED OCCASIONAL LIGHT RAIN WILL LIMIT HIGH
TEMPS TO THE 50S MOST LOW ELEVATION AREAS.

LATE THU NIGHT...AND ESP FRI BETTER MOISTURE ARRIVES AS A NORTHERN
STREAM SHORT WAVE DROPS DOWN THROUGH BC WITH A TRUE COLD FRONT
DROPPING DOWN THE COAST AHEAD OF IT. MOIST ISENTROPIC LIFT IN THE
LOWER LEVELS IMPROVES AHEAD OF THE COLD FRONT AS WELL...BEST
DEPICTED IN MODEL 290K ISENTROPIC FIELDS. AS SUCH...POTENTIAL FOR
RAIN PICKS UP CONSIDERABLY BY FRI.

MODELS IN RELATIVELY GOOD AGREEMENT IN DEPICTING THE WESTERN
CANADIAN TROUGH DIGGING DOWN INTO THE PACIFIC NW STATES FRI NIGHT
AND SAT. ALL MODELS AT THIS POINT SHOWING A VIGOROUS CONTINENTAL
TYPE COLD FRONT MOVING S THROUGH SW WA AND NW OREGON FRI NIGHT.
PATTERN IS REMINISCENT OF A COLD FRONT FROM BACK ON 19 NOVEMBER 2003
THAT BROUGHT LOW ELEVATION SNOW TO INTERIOR N PARTS OF THE FORECAST
AREA. KEYS TO DOING SOMETHING SIMILAR RELY ON SOME OF THE
PRECIPITATION FALLING OVER AND BEHIND THE FRONT AS WELL AS STRONG
FRONTOGENETIC FORCING TO ALLOW FOR DYNAMIC COOLING. MODEL SOUNDINGS
AT THIS POINT INDICATE SNOW LEVEL FALLING RAPIDLY BEHIND THE FRONT
FRI NIGHT SUGGESTING AT LEAST A MIX OF RAIN AND SNOW POSSIBLE DOWN
TO FAIRLY LOW LEVELS. WHETHER IT WOULD BE COLD ENOUGH TO MIX SNOW AT
LOWEST ELEVATIONS IS ANYBODYS GUESS AT THIS POINT...BUT GIVEN THE
AGREEMENT IN MODELS AT THIS POINT WILL CARRY A MENTION OF MIXED RAIN
AND SNOW POSSIBLE FOR THE N PART OF THE AREA FRI NIGHT. SAT SEES A
RATHER COLD AIR MASS SETTLING IN OVER THE REGION BEHIND THE FRONT...
WITH A LINGERING CHANCE FOR SHOWERS...POTENTIALLY MIXED WITH SNOW IN
THE N...AS THE UPPER TROUGH MOVES THROUGH.

LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY...MOST GUIDANCE
SUGGESTS THE UPPER TROUGH AXIS RESPONSIBLE FOR SATURDAYS MIXED
RAIN/SNOW SHOWERS WILL BE MOVING ACROSS THE CASCADES SAT NIGHT...
WITH ANY LINGERING SNOW SHOWERS COMING TO END OVERNIGHT. EXPECT SOME
CLEARING SAT NIGHT AS COLD HIGH PRESSURE BUILDS DOWN FROM BRITISH
COLUMBIA...WITH LOW TEMPS LIKELY GETTING WELL INTO THE 20S FOR MOST
SPOTS. WITH HIGH PRESSURE STRENGTHENING EAST OF THE CASCADES...
EXPECT STRONG EAST WINDS TO RAMP UP THROUGH THE GORGE SUNDAY MORNING
AND PERSIST FOR MUCH OF THE PERIOD THROUGH WEDNESDAY...WITH BREEZY
CONDITIONS SPILLING INTO THE PORTLAND/VANCOUVER METRO. MONDAY MAY BE
A BRIEF BREAK FROM THE WINDS AS A SYSTEM PASSES BY TO OUR NORTH.

MEANWHILE...A DISTURBANCE FROM THE ALEUTIANS IS EXPECTED TO CUT OFF
FROM THE MAIN PACIFIC JET AND SETTLE OFF THE CALIFORNIA COAST BY
SUNDAY...WHERE IT WILL LIKELY LINGER FOR A COUPLE DAYS. THERE IS A
CHANCE THIS SYSTEM COULD COME CLOSE ENOUGH TO SPREAD SOME PRECIP
NORTHWARD INTO OUR FORECAST AREA SUN NIGHT OR MON. THE 12Z GFS AND
CANADIAN MODELS ARE MORE AGGRESSIVE WITH THIS THAN THE ECMWF. IF
THIS OCCURS...THERE MAY BE SOME LIGHT FREEZING RAIN IN PORTIONS OF
THE WILLAMETTE VALLEY WITH SOME SNOW OR LIGHT FREEZING RAIN IN THE
GORGE. CUTOFF LOWS SUCH AS THIS ONE ARE NOTORIOUSLY DIFFICULT TO
FORECAST...AS MODELS STRUGGLE WITH THEM IN THE EXTENDED FORECAST
PERIOD. WHERE THIS UPPER LOW GOES WILL DICTATE THE WEATHER THROUGH
MIDWEEK...BUT TEMPS ARE EXPECTED TO SLOWLY MODERATE TUESDAY AND
WEDNESDAY.  WEAGLE
&&

.AVIATION...VFR CONTINUES FOR NOW EXCEPT FOR KAST WHERE PASSING
RAIN BANDS HAVE BRIEFLY LOWERED THE CIGS TO AROUND 029. EXPECT THE
OVERALL CONDITIONS TO CONTINUE DETERIORATING OVER THE NEXT SEVERAL
HOURS AS THE OFFSHORE COLD FRONT CONTINUES ITS APPROACH. EVEN THEN
LATEST GUIDANCE IS NOT TERRIBLY PESSIMISTIC WITH FLIGHT
CONDITIONS AHEAD OF AND WITH THE FRONTAL PASSAGE. RADAR BACKS THIS
UP AS RETURNS ARE FAIRLY DISJOINTED IMPLYING A LACK OF
ORGANIZATION. AS SUCH...WILL CONTINUE THE PREVIOUS PACKAGES INTENT
OF SHOWING A LOWER AND WEAKLY CONVECTIVE DECK AFTER THE FRONT AND
LASTING THROUGH MOST OF THURSDAY. THIS APPEARS TO RESULT IN IFR
CIGS AT THE COAST AND MVFR CIGS AROUND 020 INLAND.

KPDX AND APPROACHES...VFR CONDITIONS TO PREVAIL THROUGH AT LEAST
12Z THU WITH VISUAL APPROACHED BECOMING IMPACTED SHORTLY
THEREAFTER AS THE DECK LOWERS BEYOND 040. WILL LIKELY SEE CIGS
BOTTOM OUT AROUND 020 CLOSER TO 18Z WITH LITTLE LIFT FOR THE
REMAINDER OF THE LOCAL CALENDAR DAY. /JBONK

&&

.MARINE...WINDS HAVE BEEN UNDER PERFORMING THUS FAR TONIGHT WITH
THE HRRR MODEL HAVING AS GOOD OF A HANDLE AS ANYTHING. DO EXPECT
COASTAL JET ENHANCEMENT AS THE FRONT NEARS TONIGHT BUT LAST FEW
RUNS OF THE HRRR ONLY INDICATE A VERY MARGINAL GALE GUST SCENARIO
FROM ABOUT 15 NM OUT TOWARDS SHORE. BEST WINDS WILL STAY WELL
ELEVATED OFF THE WATER SURFACE AS BROAD ATMOSPHERIC LIFT IS NOT
SUPPORTING THE HIGHER SPEEDS GETTING MIXED TO THE SURFACE. WILL
MAINTAIN THE GALE WARNING SINCE IT HAS ALREADY BEEN ISSUED.

BEHIND THE FRONT...HIGH-END SMALL CRAFT ADVISORY SPEEDS PERSIST
THU MORNING. LATEST MODEL RUNS SHOW 20-25 KT NW-N WIND DEVELOPING
OVER THE N WATERS FRI EVENING THEN SPREADING FURTHER S OVERNIGHT
AS A STRONG COLD FRONT DROPS SOUTH OUT OF CANADA. THE WIND TURNS
OFFSHORE SAT WITH POTENTIAL GUSTS 20 TO 30 KT NEAR GAPS IN THE
COASTAL TERRAIN. WIND SPEEDS RELAX SUN.

SEAS EXPECTED TO BUILD TO 10 FT THIS EVENING THEN REMAIN AT OR
ABOVE 10 FT THROUGH AT LEAST SAT MORNING. WAVE HEIGHTS DROP OFF
SAT AFTERNOON AS OFFSHORE FLOW DEVELOPS. JBONK/WEISHAAR

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...GALE WARNING UNTIL 4 AM PST THURSDAY FOR COASTAL WATERS FROM
     CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 4 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 270512
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
901 PM PST WED NOV 26 2014

.SYNOPSIS...A WEAK COLD FRONT WILL PUSH SLOWLY INLAND TONIGHT AND
EARLY THU. THE FRONT WILL THEN STALL OVER WESTERN OREGON THU NIGHT
AND FRI...BEFORE ANOTHER STRONGER COLD FRONT WILL MOVE S THROUGH THE
REGION FRI NIGHT USHERING COLDER WEATHER FOR THE WEEKEND. HIGH PRES
OVER THE INTERIOR NW WILL TURN THE FLOW OFFSHORE BY SUN FOR DRY BUT
COLD WEATHER. SUN NIGHT AND MON A SYSTEM COMING UP FROM THE S WILL
ATTEMPT TO SPREAD SOME PRECIPITATION UP OVER THE COLD AIR MASS LEFT
OVER FROM THE WEEKEND.
&&

.UPDATE...NWS DOPPLER RADAR DEPICTS PRECIPITATION BEGINNING TO
SPREAD ONSHORE ACROSS THE REGION...THROUGH OBSERVATIONS
INDICATE THAT ACCUMULATIONS HAVE BEEN LIMITED THUS FAR...GENERALLY
ONLY A TRACE OR FEW HUNDREDTHS OF AN INCH AT BEST. FORECAST REMAINS
GENERALLY ON TRACK...BUT INCREASED POPS A BIT ALONG THE CENTRAL
OREGON COAST THROUGH THE NEAR TERM PER RADAR AND SATELLITE TRENDS.
THE FRONTAL BAND OF PRECIPITATION APPEARS SOMEWHAT DISJOINTED IN
APPEARANCE AND EXPECT RAINFALL TO BE INITIALLY LIGHT FOR THE NEXT FEW
HOURS...BEFORE INCREASING LATER TONIGHT THROUGH EARLY THU. LATEST
MODEL GUIDANCE SUGGESTS THAT THE SYSTEM MAY SPLIT N AND S...LEAVING
MANY PORTIONS OF THE AREA WITH ONLY OCCASIONAL LIGHT RAIN FROM MIDDAY
THU THROUGH THU EVENING. ALSO NUDGED FORECAST LOW TEMPERATURES FOR
TONIGHT A FEW DEGREES LOWER IN LINE WITH OBSERVATIONS AND GUIDANCE.
CULLEN
&&

.PREVIOUS DISCUSSION... /ISSUED 200 PM PST WED NOV 26 2014/

SHORT TERM...A WEAK COLD FRONT WAS OFFSHORE WED AFTERNOON...WITH
LAYERED CLOUDS SPREAD OUT AHEAD OF THE FRONT OVER THE PACIFIC NW. AS
THE UPPER RIDGE OVER THE REGION SHIFTS E TONIGHT AND THU THE FLOW
WILL TURN MORE TO THE SW...WITH THE FRONT SLOWLY PUSHING INLAND.
MODEL SOUNDINGS AGREE IN SHOWING MOISTURE INITIALLY IN THEMID AND
HIGH LEVELS...ABOVE 700MB. BY LATE TONIGHT THOUGH MOISTURE BEGINS TO
SPREAD IN IN THE LOWER LEVELS. DYNAMICS WITH THIS FRONT HOWEVER ON
THE WEAK SIDE...SO WILL BE SLOW TO INCREASE POPS OVERNIGHT INLAND
AREAS...WHILE THE COAST AND COAST RANGE WILL BENEFIT FROM AN
INCREASING LOW LEVEL SSW FLOW. WITH CLOUDS LIMITING RADIATIONAL
COOLING TONIGHT AND MUCH OF THE AREA STILL IN THE WARM SECTOR...
SHOULD BE ANOTHER UNSEASONABLY MILD NIGHT. THU THE FRONT APPEARS TO
STALL OVER THE REGION AS THE LOW OFFSHORE DIGS IN A BIT MORE. WITH
BAROCLINIC ZONE STALLED AND LOW LEVEL FLOW A LITTLE MORE ONSHORE
WILL TAKE POPS BACK UP TO LIKELY TO CATEGORICAL FOR MOST OF THE
REGION. ALTHOUGH THERE IS ONLY MODEST COOLING TO AIR MASS WITH THE
FRONT...CLOUDS AND EXPECTED OCCASIONAL LIGHT RAIN WILL LIMIT HIGH
TEMPS TO THE 50S MOST LOW ELEVATION AREAS.

LATE THU NIGHT...AND ESP FRI BETTER MOISTURE ARRIVES AS A NORTHERN
STREAM SHORT WAVE DROPS DOWN THROUGH BC WITH A TRUE COLD FRONT
DROPPING DOWN THE COAST AHEAD OF IT. MOIST ISENTROPIC LIFT IN THE
LOWER LEVELS IMPROVES AHEAD OF THE COLD FRONT AS WELL...BEST
DEPICTED IN MODEL 290K ISENTROPIC FIELDS. AS SUCH...POTENTIAL FOR
RAIN PICKS UP CONSIDERABLY BY FRI.

MODELS IN RELATIVELY GOOD AGREEMENT IN DEPICTING THE WESTERN
CANADIAN TROUGH DIGGING DOWN INTO THE PACIFIC NW STATES FRI NIGHT
AND SAT. ALL MODELS AT THIS POINT SHOWING A VIGOROUS CONTINENTAL
TYPE COLD FRONT MOVING S THROUGH SW WA AND NW OREGON FRI NIGHT.
PATTERN IS REMINISCENT OF A COLD FRONT FROM BACK ON 19 NOVEMBER 2003
THAT BROUGHT LOW ELEVATION SNOW TO INTERIOR N PARTS OF THE FORECAST
AREA. KEYS TO DOING SOMETHING SIMILAR RELY ON SOME OF THE
PRECIPITATION FALLING OVER AND BEHIND THE FRONT AS WELL AS STRONG
FRONTOGENETIC FORCING TO ALLOW FOR DYNAMIC COOLING. MODEL SOUNDINGS
AT THIS POINT INDICATE SNOW LEVEL FALLING RAPIDLY BEHIND THE FRONT
FRI NIGHT SUGGESTING AT LEAST A MIX OF RAIN AND SNOW POSSIBLE DOWN
TO FAIRLY LOW LEVELS. WHETHER IT WOULD BE COLD ENOUGH TO MIX SNOW AT
LOWEST ELEVATIONS IS ANYBODYS GUESS AT THIS POINT...BUT GIVEN THE
AGREEMENT IN MODELS AT THIS POINT WILL CARRY A MENTION OF MIXED RAIN
AND SNOW POSSIBLE FOR THE N PART OF THE AREA FRI NIGHT. SAT SEES A
RATHER COLD AIR MASS SETTLING IN OVER THE REGION BEHIND THE FRONT...
WITH A LINGERING CHANCE FOR SHOWERS...POTENTIALLY MIXED WITH SNOW IN
THE N...AS THE UPPER TROUGH MOVES THROUGH.

LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY...MOST GUIDANCE
SUGGESTS THE UPPER TROUGH AXIS RESPONSIBLE FOR SATURDAYS MIXED
RAIN/SNOW SHOWERS WILL BE MOVING ACROSS THE CASCADES SAT NIGHT...
WITH ANY LINGERING SNOW SHOWERS COMING TO END OVERNIGHT. EXPECT SOME
CLEARING SAT NIGHT AS COLD HIGH PRESSURE BUILDS DOWN FROM BRITISH
COLUMBIA...WITH LOW TEMPS LIKELY GETTING WELL INTO THE 20S FOR MOST
SPOTS. WITH HIGH PRESSURE STRENGTHENING EAST OF THE CASCADES...
EXPECT STRONG EAST WINDS TO RAMP UP THROUGH THE GORGE SUNDAY MORNING
AND PERSIST FOR MUCH OF THE PERIOD THROUGH WEDNESDAY...WITH BREEZY
CONDITIONS SPILLING INTO THE PORTLAND/VANCOUVER METRO. MONDAY MAY BE
A BRIEF BREAK FROM THE WINDS AS A SYSTEM PASSES BY TO OUR NORTH.

MEANWHILE...A DISTURBANCE FROM THE ALEUTIANS IS EXPECTED TO CUT OFF
FROM THE MAIN PACIFIC JET AND SETTLE OFF THE CALIFORNIA COAST BY
SUNDAY...WHERE IT WILL LIKELY LINGER FOR A COUPLE DAYS. THERE IS A
CHANCE THIS SYSTEM COULD COME CLOSE ENOUGH TO SPREAD SOME PRECIP
NORTHWARD INTO OUR FORECAST AREA SUN NIGHT OR MON. THE 12Z GFS AND
CANADIAN MODELS ARE MORE AGGRESSIVE WITH THIS THAN THE ECMWF. IF
THIS OCCURS...THERE MAY BE SOME LIGHT FREEZING RAIN IN PORTIONS OF
THE WILLAMETTE VALLEY WITH SOME SNOW OR LIGHT FREEZING RAIN IN THE
GORGE. CUTOFF LOWS SUCH AS THIS ONE ARE NOTORIOUSLY DIFFICULT TO
FORECAST...AS MODELS STRUGGLE WITH THEM IN THE EXTENDED FORECAST
PERIOD. WHERE THIS UPPER LOW GOES WILL DICTATE THE WEATHER THROUGH
MIDWEEK...BUT TEMPS ARE EXPECTED TO SLOWLY MODERATE TUESDAY AND
WEDNESDAY.  WEAGLE
&&

.AVIATION...VFR CONTINUES FOR NOW EXCEPT FOR KAST WHERE PASSING
RAIN BANDS HAVE BRIEFLY LOWERED THE CIGS TO AROUND 029. EXPECT THE
OVERALL CONDITIONS TO CONTINUE DETERIORATING OVER THE NEXT SEVERAL
HOURS AS THE OFFSHORE COLD FRONT CONTINUES ITS APPROACH. EVEN THEN
LATEST GUIDANCE IS NOT TERRIBLY PESSIMISTIC WITH FLIGHT
CONDITIONS AHEAD OF AND WITH THE FRONTAL PASSAGE. RADAR BACKS THIS
UP AS RETURNS ARE FAIRLY DISJOINTED IMPLYING A LACK OF
ORGANIZATION. AS SUCH...WILL CONTINUE THE PREVIOUS PACKAGES INTENT
OF SHOWING A LOWER AND WEAKLY CONVECTIVE DECK AFTER THE FRONT AND
LASTING THROUGH MOST OF THURSDAY. THIS APPEARS TO RESULT IN IFR
CIGS AT THE COAST AND MVFR CIGS AROUND 020 INLAND.

KPDX AND APPROACHES...VFR CONDITIONS TO PREVAIL THROUGH AT LEAST
12Z THU WITH VISUAL APPROACHED BECOMING IMPACTED SHORTLY
THEREAFTER AS THE DECK LOWERS BEYOND 040. WILL LIKELY SEE CIGS
BOTTOM OUT AROUND 020 CLOSER TO 18Z WITH LITTLE LIFT FOR THE
REMAINDER OF THE LOCAL CALENDAR DAY. /JBONK

&&

.MARINE...WINDS HAVE BEEN UNDER PERFORMING THUS FAR TONIGHT WITH
THE HRRR MODEL HAVING AS GOOD OF A HANDLE AS ANYTHING. DO EXPECT
COASTAL JET ENHANCEMENT AS THE FRONT NEARS TONIGHT BUT LAST FEW
RUNS OF THE HRRR ONLY INDICATE A VERY MARGINAL GALE GUST SCENARIO
FROM ABOUT 15 NM OUT TOWARDS SHORE. BEST WINDS WILL STAY WELL
ELEVATED OFF THE WATER SURFACE AS BROAD ATMOSPHERIC LIFT IS NOT
SUPPORTING THE HIGHER SPEEDS GETTING MIXED TO THE SURFACE. WILL
MAINTAIN THE GALE WARNING SINCE IT HAS ALREADY BEEN ISSUED.

BEHIND THE FRONT...HIGH-END SMALL CRAFT ADVISORY SPEEDS PERSIST
THU MORNING. LATEST MODEL RUNS SHOW 20-25 KT NW-N WIND DEVELOPING
OVER THE N WATERS FRI EVENING THEN SPREADING FURTHER S OVERNIGHT
AS A STRONG COLD FRONT DROPS SOUTH OUT OF CANADA. THE WIND TURNS
OFFSHORE SAT WITH POTENTIAL GUSTS 20 TO 30 KT NEAR GAPS IN THE
COASTAL TERRAIN. WIND SPEEDS RELAX SUN.

SEAS EXPECTED TO BUILD TO 10 FT THIS EVENING THEN REMAIN AT OR
ABOVE 10 FT THROUGH AT LEAST SAT MORNING. WAVE HEIGHTS DROP OFF
SAT AFTERNOON AS OFFSHORE FLOW DEVELOPS. JBONK/WEISHAAR

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...GALE WARNING UNTIL 4 AM PST THURSDAY FOR COASTAL WATERS FROM
     CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 4 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 KSEW 270011
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
410 PM PST WED NOV 26 2014

.SYNOPSIS...A FRONT WILL MOVE EAST ACROSS WESTERN WASHINGTON TONIGHT
FOR MORE RAIN AND WINDY CONDITIONS. RAIN WILL CONTINUE ON
THANKSGIVING DAY AS A COLD FRONT APPROACHES FROM THE NORTH THEN
CROSSES THE AREA ON FRIDAY. A COLD UPPER LEVEL TROUGH WILL MOVE
OVER THE AREA FRIDAY NIGHT AND SATURDAY FOR A CHANCE OF
SHOWERS...POSSIBLY MIXED WITH SNOW. COOLER AND DRY NORTHWEST FLOW
ALOFT AND A SURFACE HIGH OVER BRITISH COLUMBIA WILL COMBINE FOR COOL
DRY WEATHER AND MORE SUNSHINE SUNDAY THROUGH EARLY NEXT WEEK.

&&

.SHORT TERM...IR IMAGERY SHOWS THE FRONT OFFSHORE ALONG 130W AT 23Z
MOVING STEADILY TOWARD THE COAST. MODELS SEEM TO HAVE A GOOD HANDLE
ON THIS SYSTEM...WITH FROPA ON THE COAST AROUND MIDNIGHT AND OVER
PUGET SOUND BEFORE BEFORE 12Z/4 AM. SE PRESSURE GRADIENTS WILL
INCREASE THIS EVENING AHEAD OF THE FRONT AND LOW END WIND ADVISORY
WINDS 20-35G45 MPH MAY DEVELOP OVER THE N COAST AND PARTS OF THE N
INTERIOR. WINDS WILL EASE BEHIND THE FRONT LATE TONIGHT.

THE FRONT WILL ALSO RAISE STRONG SW LOW LEVEL WINDS OF 35-45 KT
AROUND 850 MB WHICH SHOULD BRING HEAVY OROGRAPHIC RAIN TO THE
OLYMPICS AND N CASCADES. AFTER A BRIEF LULL BEHIND TONIGHTS
FRONT...A COLD FRONT WILL MOVE S ALONG THE B.C. COAST BRINGING RAIN
AT TIMES TO W WA AHEAD OF IT THROUGH THANKSGIVING. THE COLD FRONT
WILL MOVE SLOWLY ACROSS W WA ON FRIDAY. THIS COLD FRONT IS ACTUALLY
THE OLD WARM FRONT THAT STALLED OVER SOUTHERN B.C. TODAY. A STRONG
COLD UPPER LEVEL SHORTWAVE TROUGH MOVING DOWN THE B.C. COAST WILL
SHOVE THE BAROCLINIC BAND BACK SOUTHWARD AND ACROSS W WA AS A COLD
FRONT.

SW LOW LEVEL FLOW WILL BECOME STRONG AGAIN AS THE COLD FRONT
APPROACHES THE AREA ON THURSDAY...EXTENDING THE PERIOD OF HEAVY
OROGRAPHIC RAIN OVER THE MOUNTAINS INTO FRIDAY. THE HEAVY RAIN WILL
EASE OFF FROM THE NORTH AS THE FRONT MOVES THROUGH. 48 HOUR RAINFALL
AMOUNTS FROM 00Z THURSDAY/WED AFTERNOON THROUGH 00Z SATURDAY/FRIDAY
AFTERNOON...WILL BE AROUND 4 INCHES FOR THE OLYMPICS AND 3-4.5
INCHES FOR THE NORTH CASCADES...EXCEPT FOR A BULLSEYE AROUND 6
INCHES AROUND MT BAKER. THIS MAY BRING SOME OF THE RIVERS FLOWING
OFF THE N CASCADES AND POSSIBLY PARTS OF THE CENTRAL CASCADES TO
FLOOD STAGE THURSDAY NIGHT INTO FRIDAY. SEE THE HYDROLOGY SECTION
BELOW FOR MORE DETAILS.

THE MILD AIR MASS OVER THE AREA WILL RESULT IN TEMPERATURES IN THE
50S.

ONCE THE FRONT MOVES THROUGH ON FRIDAY...THE COLD UPPER LEVEL TROUGH
WILL MOVE OVERHEAD. THE AIR MASS WILL COOL ENOUGH SO THAT SNOW
LEVELS OVER THE LOWLAND LOWER TO 500-1000 FEET LATE FRIDAY NIGHT.
RESIDUAL MOISTURE FROM THE COLD FRONT WILL REMAIN OVER THE AREA AND
THE TROUGH WILL PROVIDE SOME INSTABILITY AND LIFT. A PUGET SOUND
CONVERGENCE ZONE WILL LIKELY SET UP FRIDAY NIGHT AND EXTEND INTO
SATURDAY MORNING. SOME LIGHT SNOW IS POSSIBLE LATE FRIDAY NIGHT OVER
THE N INTERIOR...OVER THE INTERIOR AREAS OF THE N COAST AND WESTERN
STRAIT...NEAR THE CASCADES AND POSSIBLY IN THE CONVERGENCE ZONE.
SNOW LEVELS WILL LOWER TO 500-1000 FEET IN THESE AREAS. SNOW LEVELS
WILL LOWER TO BELOW 500 FEET THROUGHOUT W WA SATURDAY MORNING. WITH
THE TROUGH STILL OVERHEAD THERE WILL BE A CHANCE OF SNOW SHOWERS.
SNOW ACCUMULATIONS WILL BE LESS THAN AN INCH...BUT THERE IS ALWAYS A
CHANCE FOR A LITTLE MORE IN A CONVERGENCE ZONE. KAM

.LONG TERM...A STRONG SURFACE HIGH SETTLING OVER B.C. ON FRIDAY WILL
ALLOW COLD FRASER RIVER VALLEY OUTFLOW TO DEVELOP...BRINGING MORE
COLD AIR DRY S OVER W WA. THE AIR MASS WILL DRY OUT SATURDAY NIGHT
WITH TEMPERATURES DROPPING INTO THE 20S SUNDAY MORNING. SKIES WILL
BE MOSTLY SUNNY. THE FRASER VALLEY OUTFLOW WILL PROBABLY GENERATE
ADVISORY LEVEL NE WINDS OVER WHATCOM AND SAN JUAN COUNTY FRIDAY
NIGHT INTO SATURDAY MORNING.

THE ECMWF HAS LEANED MORE CONSISTENTLY THAN THE GFS IN KEEPING A
COOL DRY PATTERN OVER W WA INTO EARLY NEXT WEEK. THE LATEST ECMWF
NOW KEEPS THE PATTERN DRY THROUGH WEDNESDAY ALTHOUGH THERE ARE
SYSTEM THAT GET CLOSE. THE GFS HAD BEEN MORE AGGRESSIVE IN BRINGING
RAIN UP OVER THE ARE FROM THE S...BUT HAS BACKED AWAY FROM THIS ON
THE 12Z AND 18Z RUNS. IT MAY HAVE BEEN PREMATURE...BUT I HAVE DRIED
OUT EARLY NEXT WEEK. CONFIDENCE IS SHAKY BUT HOPE IT STAYS THAT WAY.
KAM

&&

.HYDROLOGY...A WARM FRONT HELD HEAVIER RAINFALL NORTH OF THE
WA/BRITISH COLUMBIA BORDER TODAY. THIS IS ALLOWING MOST RIVERS TO
SLOWLY RECEDE ACROSS WRN WA. RAIN AMOUNTS UP TO 5 INCHES SINCE
MONDAY IN PLACES LIKE MOUNT RAINIER AND THE
SKYKOMISH-SNOQUALMIE-TOLT-SNOHOMISH BASIN WILL STILL CAUSE SOME
RESIDUAL FLOODING...MAINLY THROUGH THIS EVENING.

ANOTHER FRONT WILL BRING RENEWED RAINFALL TO WRN WA TONIGHT AND
THURSDAY...LOCALLY HEAVY IN THE MOUNTAINS. THE OLYMPICS AND NORTH
CASCADES WILL RECEIVE THE HEAVIEST RAINFALL WITH 2 TO 4 INCHES OF
RAIN EXPECTED. 1 TO 2 INCHES MAY FALL IN THE CENTRAL CASCADES. THE
SNOW LEVEL WILL BE NEAR 7000 FEET.

A SECONDARY SURGE OF MOISTURE WILL ARRIVE THURSDAY NIGHT INTO
FRIDAY. MODELS VARY MUCH MORE ON THE DISTRIBUTION AND POTENTIAL
RAINFALL AMOUNTS WITH THIS SECOND FRONTAL SYSTEM. IN
GENERAL...HEAVIER RAIN AMOUNTS THURSDAY NIGHT AND FRIDAY SHOULD
OCCUR ALONG S/SW FACING SLOPES OF THE OLYMPICS AND N
CASCADES...ALTHOUGH THE CENTRAL CASCADES COULD ALSO SEE HEAVY
PRECIPITATION BY FRIDAY. ADDITIONAL AMOUNTS OF 2 TO 3 INCHES ARE
POSSIBLE. THIS MEANS THE 36-48 HOUR RAINFALL TOTALS FOR THE OLYMPICS
AND CASCADES MAY REACH 4 TO 7 INCHES WITH LOCALLY HIGHER
AMOUNTS...ESPECIALLY IN THE N CASCADES.

THESE AMOUNTS WILL LIKELY DRIVE SEVERAL RIVERS TO FLOOD...ALTHOUGH
WIDESPREAD MAJOR FLOODING APPEARS UNLIKELY. AT HIGHEST RISK FOR
FLOODING IS THE SKOKOMISH RIVER IN THE OLYMPICS...THE NOOKSACK AND
SKAGIT RIVERS IN THE NORTH...AND THE
STILLAGUAMISH...SNOQUALMIE...AND TOLT ACROSS CENTRAL AREAS. IF THE
HEAVIER RAIN SHIFTS FAR ENOUGH SOUTH THEN FLOODING COULD BE POSSIBLE
ON THE DESCHUTES RIVER AND THE REACH OF THE SKOOKUMCHUCK RIVER NEAR
BUCODA IN THURSTON COUNTY.

A FLOOD WATCH REMAINS IN EFFECT THROUGH FRIDAY...WHICH INCLUDES ALL
THE COUNTIES WITH RIVERS FLOWING OFF THE WEST SLOPES OF THE CASCADES
AND MASON COUNTY FOR THE POSSIBILITY OF A FLOOD ON THE SKOKOMISH.

COLDER AND DRIER WEATHER IS LIKELY THIS WEEKEND...SO RIVERS SHOULD
RECEDE AND THE FLOOD THREAT WILL END FOR THE FORESEEABLE FUTURE.

MERCER

&&

.AVIATION...THE FLOW ALOFT IS STRONG AND FROM THE WEST SOUTHWEST.
THE AIR MASS IS RATHER MOIST AND RELATIVELY STABLE AFTER THE PASSAGE
OF A WARM FRONT. CIGS ARE CURRENTLY MVFR TO VFR ACROSS THE AREA. A
COLD FRONT IS TIMED TO MOVE THROUGH THE AREA OVERNIGHT TONIGHT AND
DESTABILIZE THINGS...CIGS MAY RISE A BIT BEFORE THE FRONT PASSES
THROUGH...BUT THEN CIGS WILL DETERIORATE AFTERWARDS TO IFR OR MVFR.
SLY SURFACE WINDS WILL BE STRONG AND GUSTY WITH THE FRONT AND INTO
THE DAY THURSDAY.

KSEA...SOUTH WIND INCREASING TO 12 TO 14 KT OVERNIGHT WITH GUSTS TO
20 KT DURING AND AFTER FRONTAL PASSAGE AROUND 7 TO 9Z. CIGS WILL
CHANGE FROM VFR TO MVFR SHORTLY AFTER THE FRONTAL PASSAGE AS A LOWER
DECK OF CLOUDS MOVES IN. JSMITH

&&

.MARINE...A COLD FRONT WILL MOVE ONSHORE TONIGHT. GALE WARNINGS HAVE
BEEN ISSUED TONIGHT FOR THE COAST...ENTRANCES TO THE STRAIT...AND
NORTHERN INLAND WATERS AS THEY ARE MOST PRONE TO STRONG SOUTHERLY
WINDS THAT THE FRONT WILL BRING. MODERATE TO STRONG ONSHORE AND
SOUTHERLY FLOW WILL PREVAIL BEHIND THE FRONT ON THURSDAY...AND SMALL
CRAFT ADVISORIES HAVE BEEN ISSUED FOR MOST OF THE WATERS THROUGH
THURSDAY NIGHT.

ANOTHER COLD FRONT WILL MOVE THROUGH THE WATERS EARLY FRIDAY. THIS
FRONT WILL BE FOLLOWED BY STRONG FRASER OUTFLOW IN THE NORTHERN
INLAND WATERS AND MODERATE NORTHERLY WINDS OVER THE OTHER WATERS
LATER FRIDAY INTO SATURDAY. MODERATE OFFSHORE FLOW IS LIKELY SUNDAY
INTO MONDAY WITH HIGHER SEA LEVEL PRESSURE INLAND AND LOWER PRESSURE
OVER THE SOUTHERN COASTAL WATERS. JSMITH

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...FLOOD WATCHES AND WARNINGS ARE IN EFFECT FOR PORTIONS OF
      WESTERN WASHINGTON.
     WIND ADVISORY N COAST AND PARTS OF N INTERIOR TONIGHT.
PZ...SMALL CRAFT ADVISORY ALL WATERS.
    .SMALL CRAFT ADVISORY GRAYS HARBOR BAR FOR ROUGH BAR.
    .GALE WARNING COASTAL WATERS...ENTRANCES STRAIT OF JUAN DE
     FUCA...AND NORTHERN INLAND WATERS.

&&

$$

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 270011
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
410 PM PST WED NOV 26 2014

.SYNOPSIS...A FRONT WILL MOVE EAST ACROSS WESTERN WASHINGTON TONIGHT
FOR MORE RAIN AND WINDY CONDITIONS. RAIN WILL CONTINUE ON
THANKSGIVING DAY AS A COLD FRONT APPROACHES FROM THE NORTH THEN
CROSSES THE AREA ON FRIDAY. A COLD UPPER LEVEL TROUGH WILL MOVE
OVER THE AREA FRIDAY NIGHT AND SATURDAY FOR A CHANCE OF
SHOWERS...POSSIBLY MIXED WITH SNOW. COOLER AND DRY NORTHWEST FLOW
ALOFT AND A SURFACE HIGH OVER BRITISH COLUMBIA WILL COMBINE FOR COOL
DRY WEATHER AND MORE SUNSHINE SUNDAY THROUGH EARLY NEXT WEEK.

&&

.SHORT TERM...IR IMAGERY SHOWS THE FRONT OFFSHORE ALONG 130W AT 23Z
MOVING STEADILY TOWARD THE COAST. MODELS SEEM TO HAVE A GOOD HANDLE
ON THIS SYSTEM...WITH FROPA ON THE COAST AROUND MIDNIGHT AND OVER
PUGET SOUND BEFORE BEFORE 12Z/4 AM. SE PRESSURE GRADIENTS WILL
INCREASE THIS EVENING AHEAD OF THE FRONT AND LOW END WIND ADVISORY
WINDS 20-35G45 MPH MAY DEVELOP OVER THE N COAST AND PARTS OF THE N
INTERIOR. WINDS WILL EASE BEHIND THE FRONT LATE TONIGHT.

THE FRONT WILL ALSO RAISE STRONG SW LOW LEVEL WINDS OF 35-45 KT
AROUND 850 MB WHICH SHOULD BRING HEAVY OROGRAPHIC RAIN TO THE
OLYMPICS AND N CASCADES. AFTER A BRIEF LULL BEHIND TONIGHTS
FRONT...A COLD FRONT WILL MOVE S ALONG THE B.C. COAST BRINGING RAIN
AT TIMES TO W WA AHEAD OF IT THROUGH THANKSGIVING. THE COLD FRONT
WILL MOVE SLOWLY ACROSS W WA ON FRIDAY. THIS COLD FRONT IS ACTUALLY
THE OLD WARM FRONT THAT STALLED OVER SOUTHERN B.C. TODAY. A STRONG
COLD UPPER LEVEL SHORTWAVE TROUGH MOVING DOWN THE B.C. COAST WILL
SHOVE THE BAROCLINIC BAND BACK SOUTHWARD AND ACROSS W WA AS A COLD
FRONT.

SW LOW LEVEL FLOW WILL BECOME STRONG AGAIN AS THE COLD FRONT
APPROACHES THE AREA ON THURSDAY...EXTENDING THE PERIOD OF HEAVY
OROGRAPHIC RAIN OVER THE MOUNTAINS INTO FRIDAY. THE HEAVY RAIN WILL
EASE OFF FROM THE NORTH AS THE FRONT MOVES THROUGH. 48 HOUR RAINFALL
AMOUNTS FROM 00Z THURSDAY/WED AFTERNOON THROUGH 00Z SATURDAY/FRIDAY
AFTERNOON...WILL BE AROUND 4 INCHES FOR THE OLYMPICS AND 3-4.5
INCHES FOR THE NORTH CASCADES...EXCEPT FOR A BULLSEYE AROUND 6
INCHES AROUND MT BAKER. THIS MAY BRING SOME OF THE RIVERS FLOWING
OFF THE N CASCADES AND POSSIBLY PARTS OF THE CENTRAL CASCADES TO
FLOOD STAGE THURSDAY NIGHT INTO FRIDAY. SEE THE HYDROLOGY SECTION
BELOW FOR MORE DETAILS.

THE MILD AIR MASS OVER THE AREA WILL RESULT IN TEMPERATURES IN THE
50S.

ONCE THE FRONT MOVES THROUGH ON FRIDAY...THE COLD UPPER LEVEL TROUGH
WILL MOVE OVERHEAD. THE AIR MASS WILL COOL ENOUGH SO THAT SNOW
LEVELS OVER THE LOWLAND LOWER TO 500-1000 FEET LATE FRIDAY NIGHT.
RESIDUAL MOISTURE FROM THE COLD FRONT WILL REMAIN OVER THE AREA AND
THE TROUGH WILL PROVIDE SOME INSTABILITY AND LIFT. A PUGET SOUND
CONVERGENCE ZONE WILL LIKELY SET UP FRIDAY NIGHT AND EXTEND INTO
SATURDAY MORNING. SOME LIGHT SNOW IS POSSIBLE LATE FRIDAY NIGHT OVER
THE N INTERIOR...OVER THE INTERIOR AREAS OF THE N COAST AND WESTERN
STRAIT...NEAR THE CASCADES AND POSSIBLY IN THE CONVERGENCE ZONE.
SNOW LEVELS WILL LOWER TO 500-1000 FEET IN THESE AREAS. SNOW LEVELS
WILL LOWER TO BELOW 500 FEET THROUGHOUT W WA SATURDAY MORNING. WITH
THE TROUGH STILL OVERHEAD THERE WILL BE A CHANCE OF SNOW SHOWERS.
SNOW ACCUMULATIONS WILL BE LESS THAN AN INCH...BUT THERE IS ALWAYS A
CHANCE FOR A LITTLE MORE IN A CONVERGENCE ZONE. KAM

.LONG TERM...A STRONG SURFACE HIGH SETTLING OVER B.C. ON FRIDAY WILL
ALLOW COLD FRASER RIVER VALLEY OUTFLOW TO DEVELOP...BRINGING MORE
COLD AIR DRY S OVER W WA. THE AIR MASS WILL DRY OUT SATURDAY NIGHT
WITH TEMPERATURES DROPPING INTO THE 20S SUNDAY MORNING. SKIES WILL
BE MOSTLY SUNNY. THE FRASER VALLEY OUTFLOW WILL PROBABLY GENERATE
ADVISORY LEVEL NE WINDS OVER WHATCOM AND SAN JUAN COUNTY FRIDAY
NIGHT INTO SATURDAY MORNING.

THE ECMWF HAS LEANED MORE CONSISTENTLY THAN THE GFS IN KEEPING A
COOL DRY PATTERN OVER W WA INTO EARLY NEXT WEEK. THE LATEST ECMWF
NOW KEEPS THE PATTERN DRY THROUGH WEDNESDAY ALTHOUGH THERE ARE
SYSTEM THAT GET CLOSE. THE GFS HAD BEEN MORE AGGRESSIVE IN BRINGING
RAIN UP OVER THE ARE FROM THE S...BUT HAS BACKED AWAY FROM THIS ON
THE 12Z AND 18Z RUNS. IT MAY HAVE BEEN PREMATURE...BUT I HAVE DRIED
OUT EARLY NEXT WEEK. CONFIDENCE IS SHAKY BUT HOPE IT STAYS THAT WAY.
KAM

&&

.HYDROLOGY...A WARM FRONT HELD HEAVIER RAINFALL NORTH OF THE
WA/BRITISH COLUMBIA BORDER TODAY. THIS IS ALLOWING MOST RIVERS TO
SLOWLY RECEDE ACROSS WRN WA. RAIN AMOUNTS UP TO 5 INCHES SINCE
MONDAY IN PLACES LIKE MOUNT RAINIER AND THE
SKYKOMISH-SNOQUALMIE-TOLT-SNOHOMISH BASIN WILL STILL CAUSE SOME
RESIDUAL FLOODING...MAINLY THROUGH THIS EVENING.

ANOTHER FRONT WILL BRING RENEWED RAINFALL TO WRN WA TONIGHT AND
THURSDAY...LOCALLY HEAVY IN THE MOUNTAINS. THE OLYMPICS AND NORTH
CASCADES WILL RECEIVE THE HEAVIEST RAINFALL WITH 2 TO 4 INCHES OF
RAIN EXPECTED. 1 TO 2 INCHES MAY FALL IN THE CENTRAL CASCADES. THE
SNOW LEVEL WILL BE NEAR 7000 FEET.

A SECONDARY SURGE OF MOISTURE WILL ARRIVE THURSDAY NIGHT INTO
FRIDAY. MODELS VARY MUCH MORE ON THE DISTRIBUTION AND POTENTIAL
RAINFALL AMOUNTS WITH THIS SECOND FRONTAL SYSTEM. IN
GENERAL...HEAVIER RAIN AMOUNTS THURSDAY NIGHT AND FRIDAY SHOULD
OCCUR ALONG S/SW FACING SLOPES OF THE OLYMPICS AND N
CASCADES...ALTHOUGH THE CENTRAL CASCADES COULD ALSO SEE HEAVY
PRECIPITATION BY FRIDAY. ADDITIONAL AMOUNTS OF 2 TO 3 INCHES ARE
POSSIBLE. THIS MEANS THE 36-48 HOUR RAINFALL TOTALS FOR THE OLYMPICS
AND CASCADES MAY REACH 4 TO 7 INCHES WITH LOCALLY HIGHER
AMOUNTS...ESPECIALLY IN THE N CASCADES.

THESE AMOUNTS WILL LIKELY DRIVE SEVERAL RIVERS TO FLOOD...ALTHOUGH
WIDESPREAD MAJOR FLOODING APPEARS UNLIKELY. AT HIGHEST RISK FOR
FLOODING IS THE SKOKOMISH RIVER IN THE OLYMPICS...THE NOOKSACK AND
SKAGIT RIVERS IN THE NORTH...AND THE
STILLAGUAMISH...SNOQUALMIE...AND TOLT ACROSS CENTRAL AREAS. IF THE
HEAVIER RAIN SHIFTS FAR ENOUGH SOUTH THEN FLOODING COULD BE POSSIBLE
ON THE DESCHUTES RIVER AND THE REACH OF THE SKOOKUMCHUCK RIVER NEAR
BUCODA IN THURSTON COUNTY.

A FLOOD WATCH REMAINS IN EFFECT THROUGH FRIDAY...WHICH INCLUDES ALL
THE COUNTIES WITH RIVERS FLOWING OFF THE WEST SLOPES OF THE CASCADES
AND MASON COUNTY FOR THE POSSIBILITY OF A FLOOD ON THE SKOKOMISH.

COLDER AND DRIER WEATHER IS LIKELY THIS WEEKEND...SO RIVERS SHOULD
RECEDE AND THE FLOOD THREAT WILL END FOR THE FORESEEABLE FUTURE.

MERCER

&&

.AVIATION...THE FLOW ALOFT IS STRONG AND FROM THE WEST SOUTHWEST.
THE AIR MASS IS RATHER MOIST AND RELATIVELY STABLE AFTER THE PASSAGE
OF A WARM FRONT. CIGS ARE CURRENTLY MVFR TO VFR ACROSS THE AREA. A
COLD FRONT IS TIMED TO MOVE THROUGH THE AREA OVERNIGHT TONIGHT AND
DESTABILIZE THINGS...CIGS MAY RISE A BIT BEFORE THE FRONT PASSES
THROUGH...BUT THEN CIGS WILL DETERIORATE AFTERWARDS TO IFR OR MVFR.
SLY SURFACE WINDS WILL BE STRONG AND GUSTY WITH THE FRONT AND INTO
THE DAY THURSDAY.

KSEA...SOUTH WIND INCREASING TO 12 TO 14 KT OVERNIGHT WITH GUSTS TO
20 KT DURING AND AFTER FRONTAL PASSAGE AROUND 7 TO 9Z. CIGS WILL
CHANGE FROM VFR TO MVFR SHORTLY AFTER THE FRONTAL PASSAGE AS A LOWER
DECK OF CLOUDS MOVES IN. JSMITH

&&

.MARINE...A COLD FRONT WILL MOVE ONSHORE TONIGHT. GALE WARNINGS HAVE
BEEN ISSUED TONIGHT FOR THE COAST...ENTRANCES TO THE STRAIT...AND
NORTHERN INLAND WATERS AS THEY ARE MOST PRONE TO STRONG SOUTHERLY
WINDS THAT THE FRONT WILL BRING. MODERATE TO STRONG ONSHORE AND
SOUTHERLY FLOW WILL PREVAIL BEHIND THE FRONT ON THURSDAY...AND SMALL
CRAFT ADVISORIES HAVE BEEN ISSUED FOR MOST OF THE WATERS THROUGH
THURSDAY NIGHT.

ANOTHER COLD FRONT WILL MOVE THROUGH THE WATERS EARLY FRIDAY. THIS
FRONT WILL BE FOLLOWED BY STRONG FRASER OUTFLOW IN THE NORTHERN
INLAND WATERS AND MODERATE NORTHERLY WINDS OVER THE OTHER WATERS
LATER FRIDAY INTO SATURDAY. MODERATE OFFSHORE FLOW IS LIKELY SUNDAY
INTO MONDAY WITH HIGHER SEA LEVEL PRESSURE INLAND AND LOWER PRESSURE
OVER THE SOUTHERN COASTAL WATERS. JSMITH

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...FLOOD WATCHES AND WARNINGS ARE IN EFFECT FOR PORTIONS OF
      WESTERN WASHINGTON.
     WIND ADVISORY N COAST AND PARTS OF N INTERIOR TONIGHT.
PZ...SMALL CRAFT ADVISORY ALL WATERS.
    .SMALL CRAFT ADVISORY GRAYS HARBOR BAR FOR ROUGH BAR.
    .GALE WARNING COASTAL WATERS...ENTRANCES STRAIT OF JUAN DE
     FUCA...AND NORTHERN INLAND WATERS.

&&

$$

WWW.WEATHER.GOV/SEATTLE

YOU CAN SEE AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION AT
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000
FXUS66 KOTX 262344
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
343 PM PST WED NOV 26 2014

.SYNOPSIS...
Mild and breezy weather is expected tonight and Thanksgiving with
areas of dense fog. Snow levels should rise above the mountain
passes. Motorists with plans to travel over the mountain passes
should experience good conditions this afternoon through Friday
afternoon. The arrival of a cold front Friday night into Saturday
will bring winter driving conditions to the mountain passes and
much cooler weather for the weekend.

&&

.DISCUSSION...
Tonight and Thursday: The region remains under a dirty upper-level
ridge. In general, the ridge is bringing much warmer air into the
region (at least in the midlevels) and is shoving the moist
frontal boundary northward into southern BC. Because the ridge has
fully translated east, some of this moisture is coming down the
eastern periphery of the ridge and continuing to bring light rain
and high mountain snow into the northern Idaho Panhandle. The
biggest impacts from the warming aloft is a moist inversion over
the Basin delivering widespread fog and low clouds. Dense fog has
plagued the Upper Columbia Basin through much of the day and will
continue for much of the night. As of 2PM...the worse visibilities
were found along Hwy 2 from Airway Heights to Waterville and
northward along Hwy 395 between Spokane and Colville. As such, a
dense fog advisory has been issued.

As we go into the night and Thanksgiving, the ridge will flatten
and the moist frontal boundary will sag back into Washington and
Northern Idaho. We will not see much in the way of cooling north
of the boundary but rather an increase in precipitation. The good
news is winds should begin picking up and we will lose the pockets
of cooler air in the northern valleys resulting in snow levels
between 5-6K ft. Modest westerly flow within the 850-700mb layer
will deliver somewhat of a rain shadow in the Basin but add lift
to the already strong isentropic omega over the northern and
eastern mountains.

Under this pattern, a wide range of temperatures will be found
across the region. Today for instance, we are seeing highs in the
30`s north to 60`s in the foothills of the Blue Mtns. Overnight
lows will drop very little from the current readings (with the
exception of the 60`s in the southeast) then tomorrow will have
the potential for widespread 40s and 50s with a few 60`s if the
winds can efficiency mix to the valley floors.  /sb

Thursday night through Saturday...A complex interplay between an
initially very moist air mass and a strong arctic push will bring
a very active weather regime to the region through this
period...featuring wet and windy but surprisingly mild late
November conditions Thursday night through Friday night...with a
stark drying trend with temperatures beginning to plunge like a
rock on Saturday.

Two features of note on Pacific satellite are the deep closed low
spinning off the coast...hosting a very moist air mass...and an
incipient arctic origin trough barely perceptible on satellite
over the Yukon dropping into northern BC this afternoon. The
latest GFS and ECMWF models are in better agreement today and
honing in on a solution that involves the digging arctic trough
picking up and enhancing the Pacific moisture over the forecast
area into a long running semi-orographic precipitation pattern
followed by a strong push of very dry arctic air down the Okanogan
Valley and eventually exchanging the current moist maritime air
mass over the region with a bone dry and cold air mass.

Thursday night will include a moist orographic pattern with
strong westerly flow across the mountains promoting a decent rain
shadow over the basin...with snow levels in this mild maritime
air mass maintaining between 5000 and 6000 feet. On Friday a deep
surface low pressure will form to the north and deepen
aggressively under the dynamic jet region ahead of the incoming
trough as it descends through the forecast area. This will allow
rain and high mountain snow to become more widespread and include
most of the Columbia Basin during the day Friday. Winds will
become very gusty during Friday afternoon especially over the
exposed basin terrain...and a Wind Advisory may be necessary with
model soundings suggesting 45 to 50 mph gust potential in the
mixed layer. This will also promote continued mild temperatures.

Friday night the arctic cold front will follow the now exiting
surface low with an impressively strong northerly gradient setting
up down the Okanogan Valley and eventually encompassing the deep
basin by Saturday. This is another potential Wind Advisory or
even a High Wind Warning pattern that will need to be monitored
and refined on subsequent shifts. By Saturday afternoon a stark
clearing trend from north to south will become apparent as very
dry air invades the region. As snow levels quickly drop
precipitation will be quickly ending so no winter storm highlights
are expected. Temperatures on Saturday may start out at their
high temperatures and either remain steady or plunge during the
day. /Fugazzi

Saturday Night through Sunday Night: A trough will exit the
region Saturday night with the best chance of snow extending from
Pullman south toward the Blue Mountains and Camas Prairie. The
flow will turn north to northeasterly which will bring in cold
Canadian air. Min temperatures will be about 7-14 degrees below
average for this time of the year. Temps in the single digits to
low teens will be common. Below zero is not out of the question
for the Methow and Okanogan Valleys. Sunday and Sunday Night the
models agree on showing a broad ridge in place with very dry
conditions. Have taken out all previous mention of snow and
decreased sky cover. There is the potential for valley fog, but am
not confident quite yet as to where it would form. Will have to
wait to see how much drying we get behind the trough.

Monday through Wednesday: Both the EC and GFS show another trough
moving through the area on Monday. There are some discrepancies
between the two...mainly being the GFS takes the main energy and
slides it along the Canadian border where the EC digs it further
south into our area. So we have some discrepancies as to where the
best chance of rain and snow will set up. Right now am trending
more towards the wetter/slightly warmer GFS and have chance of
precipitation across extreme eastern WA and all of the ID
Panhandle. This is quite a bit different from the previous
forecast that had a chance of precip just about everywhere. After
the trough passes Monday another broad ridge sets up across the
Inland Northwest. The best chance of precip will remain across
southeast WA and the LC Valley/Camas Prairie areas. Temperatures
will start to moderate a bit, but will still be below average for
this time of the year. /Nisbet

&&

.AVIATION...
00Z TAFS: A very moist boundary layer will promote widespread IFR
and LIFR ceilings and visibilities over the Columbia Basin through
06Z...affecting all TAF sites except KPUW and KLWS. After 06Z a
developing surface low over British Columbia will create a
southerly gradient breeze which may allow some improvement in
visibilities and marginal ceiling improvement...however since this
will be developing at night and thus involving a nocturnal
inversion locking in the low level moisture...confidence is only
moderate for this improvement. Confidence is higher for
significant improvement during the mid morning hours on Thursday
when diurnal mixing will play a larger role in breaking up the fog
and stratus.

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        39  49  41  46  27  30 /  30  30  20  70  60  10
Coeur d`Alene  36  47  41  45  29  31 /  30  40  40  80  70  20
Pullman        44  52  43  49  32  34 /  20  30  30  90  90  50
Lewiston       43  55  46  53  38  40 /  10  10  20  60  70  60
Colville       36  45  40  43  22  24 /  60  50  50  70  30  10
Sandpoint      33  45  38  42  26  26 /  70  60  70  80  80  20
Kellogg        37  44  39  41  30  31 /  60  80  60  90 100  50
Moses Lake     38  52  41  51  27  31 /  10  10  20  30  30  10
Wenatchee      39  47  41  48  29  30 /  10  10  30  30  20  10
Omak           34  43  37  41  16  20 /  30  20  20  20  20  10

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...Dense Fog Advisory until 10 PM PST this evening for Northeast
     Mountains-Spokane Area-Upper Columbia Basin-Waterville
     Plateau.

&&

$$




000
FXUS66 KOTX 262344
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
343 PM PST WED NOV 26 2014

.SYNOPSIS...
Mild and breezy weather is expected tonight and Thanksgiving with
areas of dense fog. Snow levels should rise above the mountain
passes. Motorists with plans to travel over the mountain passes
should experience good conditions this afternoon through Friday
afternoon. The arrival of a cold front Friday night into Saturday
will bring winter driving conditions to the mountain passes and
much cooler weather for the weekend.

&&

.DISCUSSION...
Tonight and Thursday: The region remains under a dirty upper-level
ridge. In general, the ridge is bringing much warmer air into the
region (at least in the midlevels) and is shoving the moist
frontal boundary northward into southern BC. Because the ridge has
fully translated east, some of this moisture is coming down the
eastern periphery of the ridge and continuing to bring light rain
and high mountain snow into the northern Idaho Panhandle. The
biggest impacts from the warming aloft is a moist inversion over
the Basin delivering widespread fog and low clouds. Dense fog has
plagued the Upper Columbia Basin through much of the day and will
continue for much of the night. As of 2PM...the worse visibilities
were found along Hwy 2 from Airway Heights to Waterville and
northward along Hwy 395 between Spokane and Colville. As such, a
dense fog advisory has been issued.

As we go into the night and Thanksgiving, the ridge will flatten
and the moist frontal boundary will sag back into Washington and
Northern Idaho. We will not see much in the way of cooling north
of the boundary but rather an increase in precipitation. The good
news is winds should begin picking up and we will lose the pockets
of cooler air in the northern valleys resulting in snow levels
between 5-6K ft. Modest westerly flow within the 850-700mb layer
will deliver somewhat of a rain shadow in the Basin but add lift
to the already strong isentropic omega over the northern and
eastern mountains.

Under this pattern, a wide range of temperatures will be found
across the region. Today for instance, we are seeing highs in the
30`s north to 60`s in the foothills of the Blue Mtns. Overnight
lows will drop very little from the current readings (with the
exception of the 60`s in the southeast) then tomorrow will have
the potential for widespread 40s and 50s with a few 60`s if the
winds can efficiency mix to the valley floors.  /sb

Thursday night through Saturday...A complex interplay between an
initially very moist air mass and a strong arctic push will bring
a very active weather regime to the region through this
period...featuring wet and windy but surprisingly mild late
November conditions Thursday night through Friday night...with a
stark drying trend with temperatures beginning to plunge like a
rock on Saturday.

Two features of note on Pacific satellite are the deep closed low
spinning off the coast...hosting a very moist air mass...and an
incipient arctic origin trough barely perceptible on satellite
over the Yukon dropping into northern BC this afternoon. The
latest GFS and ECMWF models are in better agreement today and
honing in on a solution that involves the digging arctic trough
picking up and enhancing the Pacific moisture over the forecast
area into a long running semi-orographic precipitation pattern
followed by a strong push of very dry arctic air down the Okanogan
Valley and eventually exchanging the current moist maritime air
mass over the region with a bone dry and cold air mass.

Thursday night will include a moist orographic pattern with
strong westerly flow across the mountains promoting a decent rain
shadow over the basin...with snow levels in this mild maritime
air mass maintaining between 5000 and 6000 feet. On Friday a deep
surface low pressure will form to the north and deepen
aggressively under the dynamic jet region ahead of the incoming
trough as it descends through the forecast area. This will allow
rain and high mountain snow to become more widespread and include
most of the Columbia Basin during the day Friday. Winds will
become very gusty during Friday afternoon especially over the
exposed basin terrain...and a Wind Advisory may be necessary with
model soundings suggesting 45 to 50 mph gust potential in the
mixed layer. This will also promote continued mild temperatures.

Friday night the arctic cold front will follow the now exiting
surface low with an impressively strong northerly gradient setting
up down the Okanogan Valley and eventually encompassing the deep
basin by Saturday. This is another potential Wind Advisory or
even a High Wind Warning pattern that will need to be monitored
and refined on subsequent shifts. By Saturday afternoon a stark
clearing trend from north to south will become apparent as very
dry air invades the region. As snow levels quickly drop
precipitation will be quickly ending so no winter storm highlights
are expected. Temperatures on Saturday may start out at their
high temperatures and either remain steady or plunge during the
day. /Fugazzi

Saturday Night through Sunday Night: A trough will exit the
region Saturday night with the best chance of snow extending from
Pullman south toward the Blue Mountains and Camas Prairie. The
flow will turn north to northeasterly which will bring in cold
Canadian air. Min temperatures will be about 7-14 degrees below
average for this time of the year. Temps in the single digits to
low teens will be common. Below zero is not out of the question
for the Methow and Okanogan Valleys. Sunday and Sunday Night the
models agree on showing a broad ridge in place with very dry
conditions. Have taken out all previous mention of snow and
decreased sky cover. There is the potential for valley fog, but am
not confident quite yet as to where it would form. Will have to
wait to see how much drying we get behind the trough.

Monday through Wednesday: Both the EC and GFS show another trough
moving through the area on Monday. There are some discrepancies
between the two...mainly being the GFS takes the main energy and
slides it along the Canadian border where the EC digs it further
south into our area. So we have some discrepancies as to where the
best chance of rain and snow will set up. Right now am trending
more towards the wetter/slightly warmer GFS and have chance of
precipitation across extreme eastern WA and all of the ID
Panhandle. This is quite a bit different from the previous
forecast that had a chance of precip just about everywhere. After
the trough passes Monday another broad ridge sets up across the
Inland Northwest. The best chance of precip will remain across
southeast WA and the LC Valley/Camas Prairie areas. Temperatures
will start to moderate a bit, but will still be below average for
this time of the year. /Nisbet

&&

.AVIATION...
00Z TAFS: A very moist boundary layer will promote widespread IFR
and LIFR ceilings and visibilities over the Columbia Basin through
06Z...affecting all TAF sites except KPUW and KLWS. After 06Z a
developing surface low over British Columbia will create a
southerly gradient breeze which may allow some improvement in
visibilities and marginal ceiling improvement...however since this
will be developing at night and thus involving a nocturnal
inversion locking in the low level moisture...confidence is only
moderate for this improvement. Confidence is higher for
significant improvement during the mid morning hours on Thursday
when diurnal mixing will play a larger role in breaking up the fog
and stratus.

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        39  49  41  46  27  30 /  30  30  20  70  60  10
Coeur d`Alene  36  47  41  45  29  31 /  30  40  40  80  70  20
Pullman        44  52  43  49  32  34 /  20  30  30  90  90  50
Lewiston       43  55  46  53  38  40 /  10  10  20  60  70  60
Colville       36  45  40  43  22  24 /  60  50  50  70  30  10
Sandpoint      33  45  38  42  26  26 /  70  60  70  80  80  20
Kellogg        37  44  39  41  30  31 /  60  80  60  90 100  50
Moses Lake     38  52  41  51  27  31 /  10  10  20  30  30  10
Wenatchee      39  47  41  48  29  30 /  10  10  30  30  20  10
Omak           34  43  37  41  16  20 /  30  20  20  20  20  10

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...Dense Fog Advisory until 10 PM PST this evening for Northeast
     Mountains-Spokane Area-Upper Columbia Basin-Waterville
     Plateau.

&&

$$





000
FXUS66 KOTX 262343
AFDOTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
343 PM PST WED NOV 26 2014

.SYNOPSIS...
MILD AND BREEZY WEATHER IS EXPECTED TONIGHT AND THANKSGIVING WITH
AREAS OF DENSE FOG. SNOW LEVELS SHOULD RISE ABOVE THE MOUNTAIN
PASSES. MOTORISTS WITH PLANS TO TRAVEL OVER THE MOUNTAIN PASSES
SHOULD EXPERIENCE GOOD CONDITIONS THIS AFTERNOON THROUGH FRIDAY
AFTERNOON. THE ARRIVAL OF A COLD FRONT FRIDAY NIGHT INTO SATURDAY
WILL BRING WINTER DRIVING CONDITIONS TO THE MOUNTAIN PASSES AND
MUCH COOLER WEATHER FOR THE WEEKEND.

&&

.DISCUSSION...
TONIGHT AND THURSDAY: THE REGION REMAINS UNDER A DIRTY UPPER-LEVEL
RIDGE. IN GENERAL, THE RIDGE IS BRINGING MUCH WARMER AIR INTO THE
REGION (AT LEAST IN THE MIDLEVELS) AND IS SHOVING THE MOIST
FRONTAL BOUNDARY NORTHWARD INTO SOUTHERN BC. BECAUSE THE RIDGE HAS
FULLY TRANSLATED EAST, SOME OF THIS MOISTURE IS COMING DOWN THE
EASTERN PERIPHERY OF THE RIDGE AND CONTINUING TO BRING LIGHT RAIN
AND HIGH MOUNTAIN SNOW INTO THE NORTHERN IDAHO PANHANDLE. THE
BIGGEST IMPACTS FROM THE WARMING ALOFT IS A MOIST INVERSION OVER
THE BASIN DELIVERING WIDESPREAD FOG AND LOW CLOUDS. DENSE FOG HAS
PLAGUED THE UPPER COLUMBIA BASIN THROUGH MUCH OF THE DAY AND WILL
CONTINUE FOR MUCH OF THE NIGHT. AS OF 2PM...THE WORSE VISIBILITIES
WERE FOUND ALONG HWY 2 FROM AIRWAY HEIGHTS TO WATERVILLE AND
NORTHWARD ALONG HWY 395 BETWEEN SPOKANE AND COLVILLE. AS SUCH, A
DENSE FOG ADVISORY HAS BEEN ISSUED.

AS WE GO INTO THE NIGHT AND THANKSGIVING, THE RIDGE WILL FLATTEN
AND THE MOIST FRONTAL BOUNDARY WILL SAG BACK INTO WASHINGTON AND
NORTHERN IDAHO. WE WILL NOT SEE MUCH IN THE WAY OF COOLING NORTH
OF THE BOUNDARY BUT RATHER AN INCREASE IN PRECIPITATION. THE GOOD
NEWS IS WINDS SHOULD BEGIN PICKING UP AND WE WILL LOSE THE POCKETS
OF COOLER AIR IN THE NORTHERN VALLEYS RESULTING IN SNOW LEVELS
BETWEEN 5-6K FT. MODEST WESTERLY FLOW WITHIN THE 850-700MB LAYER
WILL DELIVER SOMEWHAT OF A RAIN SHADOW IN THE BASIN BUT ADD LIFT
TO THE ALREADY STRONG ISENTROPIC OMEGA OVER THE NORTHERN AND
EASTERN MOUNTAINS.

UNDER THIS PATTERN, A WIDE RANGE OF TEMPERATURES WILL BE FOUND
ACROSS THE REGION. TODAY FOR INSTANCE, WE ARE SEEING HIGHS IN THE
30`S NORTH TO 60`S IN THE FOOTHILLS OF THE BLUE MTNS. OVERNIGHT
LOWS WILL DROP VERY LITTLE FROM THE CURRENT READINGS (WITH THE
EXCEPTION OF THE 60`S IN THE SOUTHEAST) THEN TOMORROW WILL HAVE
THE POTENTIAL FOR WIDESPREAD 40S AND 50S WITH A FEW 60`S IF THE
WINDS CAN EFFICIENCY MIX TO THE VALLEY FLOORS.  /SB

THURSDAY NIGHT THROUGH SATURDAY...A COMPLEX INTERPLAY BETWEEN AN
INITIALLY VERY MOIST AIR MASS AND A STRONG ARCTIC PUSH WILL BRING
A VERY ACTIVE WEATHER REGIME TO THE REGION THROUGH THIS
PERIOD...FEATURING WET AND WINDY BUT SURPRISINGLY MILD LATE
NOVEMBER CONDITIONS THURSDAY NIGHT THROUGH FRIDAY NIGHT...WITH A
STARK DRYING TREND WITH TEMPERATURES BEGINNING TO PLUNGE LIKE A
ROCK ON SATURDAY.

TWO FEATURES OF NOTE ON PACIFIC SATELLITE ARE THE DEEP CLOSED LOW
SPINNING OFF THE COAST...HOSTING A VERY MOIST AIR MASS...AND AN
INCIPIENT ARCTIC ORIGIN TROUGH BARELY PERCEPTIBLE ON SATELLITE
OVER THE YUKON DROPPING INTO NORTHERN BC THIS AFTERNOON. THE
LATEST GFS AND ECMWF MODELS ARE IN BETTER AGREEMENT TODAY AND
HONING IN ON A SOLUTION THAT INVOLVES THE DIGGING ARCTIC TROUGH
PICKING UP AND ENHANCING THE PACIFIC MOISTURE OVER THE FORECAST
AREA INTO A LONG RUNNING SEMI-OROGRAPHIC PRECIPITATION PATTERN
FOLLOWED BY A STRONG PUSH OF VERY DRY ARCTIC AIR DOWN THE OKANOGAN
VALLEY AND EVENTUALLY EXCHANGING THE CURRENT MOIST MARITIME AIR
MASS OVER THE REGION WITH A BONE DRY AND COLD AIR MASS.

THURSDAY NIGHT WILL INCLUDE A MOIST OROGRAPHIC PATTERN WITH
STRONG WESTERLY FLOW ACROSS THE MOUNTAINS PROMOTING A DECENT RAIN
SHADOW OVER THE BASIN...WITH SNOW LEVELS IN THIS MILD MARITIME
AIR MASS MAINTAINING BETWEEN 5000 AND 6000 FEET. ON FRIDAY A DEEP
SURFACE LOW PRESSURE WILL FORM TO THE NORTH AND DEEPEN
AGGRESSIVELY UNDER THE DYNAMIC JET REGION AHEAD OF THE INCOMING
TROUGH AS IT DESCENDS THROUGH THE FORECAST AREA. THIS WILL ALLOW
RAIN AND HIGH MOUNTAIN SNOW TO BECOME MORE WIDESPREAD AND INCLUDE
MOST OF THE COLUMBIA BASIN DURING THE DAY FRIDAY. WINDS WILL
BECOME VERY GUSTY DURING FRIDAY AFTERNOON ESPECIALLY OVER THE
EXPOSED BASIN TERRAIN...AND A WIND ADVISORY MAY BE NECESSARY WITH
MODEL SOUNDINGS SUGGESTING 45 TO 50 MPH GUST POTENTIAL IN THE
MIXED LAYER. THIS WILL ALSO PROMOTE CONTINUED MILD TEMPERATURES.

FRIDAY NIGHT THE ARCTIC COLD FRONT WILL FOLLOW THE NOW EXITING
SURFACE LOW WITH AN IMPRESSIVELY STRONG NORTHERLY GRADIENT SETTING
UP DOWN THE OKANOGAN VALLEY AND EVENTUALLY ENCOMPASSING THE DEEP
BASIN BY SATURDAY. THIS IS ANOTHER POTENTIAL WIND ADVISORY OR
EVEN A HIGH WIND WARNING PATTERN THAT WILL NEED TO BE MONITORED
AND REFINED ON SUBSEQUENT SHIFTS. BY SATURDAY AFTERNOON A STARK
CLEARING TREND FROM NORTH TO SOUTH WILL BECOME APPARENT AS VERY
DRY AIR INVADES THE REGION. AS SNOW LEVELS QUICKLY DROP
PRECIPITATION WILL BE QUICKLY ENDING SO NO WINTER STORM HIGHLIGHTS
ARE EXPECTED. TEMPERATURES ON SATURDAY MAY START OUT AT THEIR
HIGH TEMPERATURES AND EITHER REMAIN STEADY OR PLUNGE DURING THE
DAY. /FUGAZZI

SATURDAY NIGHT THROUGH SUNDAY NIGHT: A TROUGH WILL EXIT THE
REGION SATURDAY NIGHT WITH THE BEST CHANCE OF SNOW EXTENDING FROM
PULLMAN SOUTH TOWARD THE BLUE MOUNTAINS AND CAMAS PRAIRIE. THE
FLOW WILL TURN NORTH TO NORTHEASTERLY WHICH WILL BRING IN COLD
CANADIAN AIR. MIN TEMPERATURES WILL BE ABOUT 7-14 DEGREES BELOW
AVERAGE FOR THIS TIME OF THE YEAR. TEMPS IN THE SINGLE DIGITS TO
LOW TEENS WILL BE COMMON. BELOW ZERO IS NOT OUT OF THE QUESTION
FOR THE METHOW AND OKANOGAN VALLEYS. SUNDAY AND SUNDAY NIGHT THE
MODELS AGREE ON SHOWING A BROAD RIDGE IN PLACE WITH VERY DRY
CONDITIONS. HAVE TAKEN OUT ALL PREVIOUS MENTION OF SNOW AND
DECREASED SKY COVER. THERE IS THE POTENTIAL FOR VALLEY FOG, BUT AM
NOT CONFIDENT QUITE YET AS TO WHERE IT WOULD FORM. WILL HAVE TO
WAIT TO SEE HOW MUCH DRYING WE GET BEHIND THE TROUGH.

MONDAY THROUGH WEDNESDAY: BOTH THE EC AND GFS SHOW ANOTHER TROUGH
MOVING THROUGH THE AREA ON MONDAY. THERE ARE SOME DISCREPANCIES
BETWEEN THE TWO...MAINLY BEING THE GFS TAKES THE MAIN ENERGY AND
SLIDES IT ALONG THE CANADIAN BORDER WHERE THE EC DIGS IT FURTHER
SOUTH INTO OUR AREA. SO WE HAVE SOME DISCREPANCIES AS TO WHERE THE
BEST CHANCE OF RAIN AND SNOW WILL SET UP. RIGHT NOW AM TRENDING
MORE TOWARDS THE WETTER/SLIGHTLY WARMER GFS AND HAVE CHANCE OF
PRECIPITATION ACROSS EXTREME EASTERN WA AND ALL OF THE ID
PANHANDLE. THIS IS QUITE A BIT DIFFERENT FROM THE PREVIOUS
FORECAST THAT HAD A CHANCE OF PRECIP JUST ABOUT EVERYWHERE. AFTER
THE TROUGH PASSES MONDAY ANOTHER BROAD RIDGE SETS UP ACROSS THE
INLAND NORTHWEST. THE BEST CHANCE OF PRECIP WILL REMAIN ACROSS
SOUTHEAST WA AND THE LC VALLEY/CAMAS PRAIRIE AREAS. TEMPERATURES
WILL START TO MODERATE A BIT, BUT WILL STILL BE BELOW AVERAGE FOR
THIS TIME OF THE YEAR. /NISBET

&&

.AVIATION...
00Z TAFS: A VERY MOIST BOUNDARY LAYER WILL PROMOTE WIDESPREAD IFR
AND LIFR CEILINGS AND VISIBILITIES OVER THE COLUMBIA BASIN THROUGH
06Z...AFFECTING ALL TAF SITES EXCEPT KPUW AND KLWS. AFTER 06Z A
DEVELOPING SURFACE LOW OVER BRITISH COLUMBIA WILL CREATE A
SOUTHERLY GRADIENT BREEZE WHICH MAY ALLOW SOME IMPROVEMENT IN
VISIBILITIES AND MARGINAL CEILING IMPROVEMENT...HOWEVER SINCE THIS
WILL BE DEVELOPING AT NIGHT AND THUS INVOLVING A NOCTURNAL
INVERSION LOCKING IN THE LOW LEVEL MOISTURE...CONFIDENCE IS ONLY
MODERATE FOR THIS IMPROVEMENT. CONFIDENCE IS HIGHER FOR
SIGNIFICANT IMPROVEMENT DURING THE MID MORNING HOURS ON THURSDAY
WHEN DIURNAL MIXING WILL PLAY A LARGER ROLE IN BREAKING UP THE FOG
AND STRATUS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SPOKANE        39  49  41  46  27  30 /  30  30  20  70  60  10
COEUR D`ALENE  36  47  41  45  29  31 /  30  40  40  80  70  20
PULLMAN        44  52  43  49  32  34 /  20  30  30  90  90  50
LEWISTON       43  55  46  53  38  40 /  10  10  20  60  70  60
COLVILLE       36  45  40  43  22  24 /  60  50  50  70  30  10
SANDPOINT      33  45  38  42  26  26 /  70  60  70  80  80  20
KELLOGG        37  44  39  41  30  31 /  60  80  60  90 100  50
MOSES LAKE     38  52  41  51  27  31 /  10  10  20  30  30  10
WENATCHEE      39  47  41  48  29  30 /  10  10  30  30  20  10
OMAK           34  43  37  41  16  20 /  30  20  20  20  20  10

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
WA...DENSE FOG ADVISORY UNTIL 10 PM PST THIS EVENING FOR NORTHEAST
     MOUNTAINS-SPOKANE AREA-UPPER COLUMBIA BASIN-WATERVILLE
     PLATEAU.

&&

$$




000
FXUS66 KOTX 262343
AFDOTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
343 PM PST WED NOV 26 2014

.SYNOPSIS...
MILD AND BREEZY WEATHER IS EXPECTED TONIGHT AND THANKSGIVING WITH
AREAS OF DENSE FOG. SNOW LEVELS SHOULD RISE ABOVE THE MOUNTAIN
PASSES. MOTORISTS WITH PLANS TO TRAVEL OVER THE MOUNTAIN PASSES
SHOULD EXPERIENCE GOOD CONDITIONS THIS AFTERNOON THROUGH FRIDAY
AFTERNOON. THE ARRIVAL OF A COLD FRONT FRIDAY NIGHT INTO SATURDAY
WILL BRING WINTER DRIVING CONDITIONS TO THE MOUNTAIN PASSES AND
MUCH COOLER WEATHER FOR THE WEEKEND.

&&

.DISCUSSION...
TONIGHT AND THURSDAY: THE REGION REMAINS UNDER A DIRTY UPPER-LEVEL
RIDGE. IN GENERAL, THE RIDGE IS BRINGING MUCH WARMER AIR INTO THE
REGION (AT LEAST IN THE MIDLEVELS) AND IS SHOVING THE MOIST
FRONTAL BOUNDARY NORTHWARD INTO SOUTHERN BC. BECAUSE THE RIDGE HAS
FULLY TRANSLATED EAST, SOME OF THIS MOISTURE IS COMING DOWN THE
EASTERN PERIPHERY OF THE RIDGE AND CONTINUING TO BRING LIGHT RAIN
AND HIGH MOUNTAIN SNOW INTO THE NORTHERN IDAHO PANHANDLE. THE
BIGGEST IMPACTS FROM THE WARMING ALOFT IS A MOIST INVERSION OVER
THE BASIN DELIVERING WIDESPREAD FOG AND LOW CLOUDS. DENSE FOG HAS
PLAGUED THE UPPER COLUMBIA BASIN THROUGH MUCH OF THE DAY AND WILL
CONTINUE FOR MUCH OF THE NIGHT. AS OF 2PM...THE WORSE VISIBILITIES
WERE FOUND ALONG HWY 2 FROM AIRWAY HEIGHTS TO WATERVILLE AND
NORTHWARD ALONG HWY 395 BETWEEN SPOKANE AND COLVILLE. AS SUCH, A
DENSE FOG ADVISORY HAS BEEN ISSUED.

AS WE GO INTO THE NIGHT AND THANKSGIVING, THE RIDGE WILL FLATTEN
AND THE MOIST FRONTAL BOUNDARY WILL SAG BACK INTO WASHINGTON AND
NORTHERN IDAHO. WE WILL NOT SEE MUCH IN THE WAY OF COOLING NORTH
OF THE BOUNDARY BUT RATHER AN INCREASE IN PRECIPITATION. THE GOOD
NEWS IS WINDS SHOULD BEGIN PICKING UP AND WE WILL LOSE THE POCKETS
OF COOLER AIR IN THE NORTHERN VALLEYS RESULTING IN SNOW LEVELS
BETWEEN 5-6K FT. MODEST WESTERLY FLOW WITHIN THE 850-700MB LAYER
WILL DELIVER SOMEWHAT OF A RAIN SHADOW IN THE BASIN BUT ADD LIFT
TO THE ALREADY STRONG ISENTROPIC OMEGA OVER THE NORTHERN AND
EASTERN MOUNTAINS.

UNDER THIS PATTERN, A WIDE RANGE OF TEMPERATURES WILL BE FOUND
ACROSS THE REGION. TODAY FOR INSTANCE, WE ARE SEEING HIGHS IN THE
30`S NORTH TO 60`S IN THE FOOTHILLS OF THE BLUE MTNS. OVERNIGHT
LOWS WILL DROP VERY LITTLE FROM THE CURRENT READINGS (WITH THE
EXCEPTION OF THE 60`S IN THE SOUTHEAST) THEN TOMORROW WILL HAVE
THE POTENTIAL FOR WIDESPREAD 40S AND 50S WITH A FEW 60`S IF THE
WINDS CAN EFFICIENCY MIX TO THE VALLEY FLOORS.  /SB

THURSDAY NIGHT THROUGH SATURDAY...A COMPLEX INTERPLAY BETWEEN AN
INITIALLY VERY MOIST AIR MASS AND A STRONG ARCTIC PUSH WILL BRING
A VERY ACTIVE WEATHER REGIME TO THE REGION THROUGH THIS
PERIOD...FEATURING WET AND WINDY BUT SURPRISINGLY MILD LATE
NOVEMBER CONDITIONS THURSDAY NIGHT THROUGH FRIDAY NIGHT...WITH A
STARK DRYING TREND WITH TEMPERATURES BEGINNING TO PLUNGE LIKE A
ROCK ON SATURDAY.

TWO FEATURES OF NOTE ON PACIFIC SATELLITE ARE THE DEEP CLOSED LOW
SPINNING OFF THE COAST...HOSTING A VERY MOIST AIR MASS...AND AN
INCIPIENT ARCTIC ORIGIN TROUGH BARELY PERCEPTIBLE ON SATELLITE
OVER THE YUKON DROPPING INTO NORTHERN BC THIS AFTERNOON. THE
LATEST GFS AND ECMWF MODELS ARE IN BETTER AGREEMENT TODAY AND
HONING IN ON A SOLUTION THAT INVOLVES THE DIGGING ARCTIC TROUGH
PICKING UP AND ENHANCING THE PACIFIC MOISTURE OVER THE FORECAST
AREA INTO A LONG RUNNING SEMI-OROGRAPHIC PRECIPITATION PATTERN
FOLLOWED BY A STRONG PUSH OF VERY DRY ARCTIC AIR DOWN THE OKANOGAN
VALLEY AND EVENTUALLY EXCHANGING THE CURRENT MOIST MARITIME AIR
MASS OVER THE REGION WITH A BONE DRY AND COLD AIR MASS.

THURSDAY NIGHT WILL INCLUDE A MOIST OROGRAPHIC PATTERN WITH
STRONG WESTERLY FLOW ACROSS THE MOUNTAINS PROMOTING A DECENT RAIN
SHADOW OVER THE BASIN...WITH SNOW LEVELS IN THIS MILD MARITIME
AIR MASS MAINTAINING BETWEEN 5000 AND 6000 FEET. ON FRIDAY A DEEP
SURFACE LOW PRESSURE WILL FORM TO THE NORTH AND DEEPEN
AGGRESSIVELY UNDER THE DYNAMIC JET REGION AHEAD OF THE INCOMING
TROUGH AS IT DESCENDS THROUGH THE FORECAST AREA. THIS WILL ALLOW
RAIN AND HIGH MOUNTAIN SNOW TO BECOME MORE WIDESPREAD AND INCLUDE
MOST OF THE COLUMBIA BASIN DURING THE DAY FRIDAY. WINDS WILL
BECOME VERY GUSTY DURING FRIDAY AFTERNOON ESPECIALLY OVER THE
EXPOSED BASIN TERRAIN...AND A WIND ADVISORY MAY BE NECESSARY WITH
MODEL SOUNDINGS SUGGESTING 45 TO 50 MPH GUST POTENTIAL IN THE
MIXED LAYER. THIS WILL ALSO PROMOTE CONTINUED MILD TEMPERATURES.

FRIDAY NIGHT THE ARCTIC COLD FRONT WILL FOLLOW THE NOW EXITING
SURFACE LOW WITH AN IMPRESSIVELY STRONG NORTHERLY GRADIENT SETTING
UP DOWN THE OKANOGAN VALLEY AND EVENTUALLY ENCOMPASSING THE DEEP
BASIN BY SATURDAY. THIS IS ANOTHER POTENTIAL WIND ADVISORY OR
EVEN A HIGH WIND WARNING PATTERN THAT WILL NEED TO BE MONITORED
AND REFINED ON SUBSEQUENT SHIFTS. BY SATURDAY AFTERNOON A STARK
CLEARING TREND FROM NORTH TO SOUTH WILL BECOME APPARENT AS VERY
DRY AIR INVADES THE REGION. AS SNOW LEVELS QUICKLY DROP
PRECIPITATION WILL BE QUICKLY ENDING SO NO WINTER STORM HIGHLIGHTS
ARE EXPECTED. TEMPERATURES ON SATURDAY MAY START OUT AT THEIR
HIGH TEMPERATURES AND EITHER REMAIN STEADY OR PLUNGE DURING THE
DAY. /FUGAZZI

SATURDAY NIGHT THROUGH SUNDAY NIGHT: A TROUGH WILL EXIT THE
REGION SATURDAY NIGHT WITH THE BEST CHANCE OF SNOW EXTENDING FROM
PULLMAN SOUTH TOWARD THE BLUE MOUNTAINS AND CAMAS PRAIRIE. THE
FLOW WILL TURN NORTH TO NORTHEASTERLY WHICH WILL BRING IN COLD
CANADIAN AIR. MIN TEMPERATURES WILL BE ABOUT 7-14 DEGREES BELOW
AVERAGE FOR THIS TIME OF THE YEAR. TEMPS IN THE SINGLE DIGITS TO
LOW TEENS WILL BE COMMON. BELOW ZERO IS NOT OUT OF THE QUESTION
FOR THE METHOW AND OKANOGAN VALLEYS. SUNDAY AND SUNDAY NIGHT THE
MODELS AGREE ON SHOWING A BROAD RIDGE IN PLACE WITH VERY DRY
CONDITIONS. HAVE TAKEN OUT ALL PREVIOUS MENTION OF SNOW AND
DECREASED SKY COVER. THERE IS THE POTENTIAL FOR VALLEY FOG, BUT AM
NOT CONFIDENT QUITE YET AS TO WHERE IT WOULD FORM. WILL HAVE TO
WAIT TO SEE HOW MUCH DRYING WE GET BEHIND THE TROUGH.

MONDAY THROUGH WEDNESDAY: BOTH THE EC AND GFS SHOW ANOTHER TROUGH
MOVING THROUGH THE AREA ON MONDAY. THERE ARE SOME DISCREPANCIES
BETWEEN THE TWO...MAINLY BEING THE GFS TAKES THE MAIN ENERGY AND
SLIDES IT ALONG THE CANADIAN BORDER WHERE THE EC DIGS IT FURTHER
SOUTH INTO OUR AREA. SO WE HAVE SOME DISCREPANCIES AS TO WHERE THE
BEST CHANCE OF RAIN AND SNOW WILL SET UP. RIGHT NOW AM TRENDING
MORE TOWARDS THE WETTER/SLIGHTLY WARMER GFS AND HAVE CHANCE OF
PRECIPITATION ACROSS EXTREME EASTERN WA AND ALL OF THE ID
PANHANDLE. THIS IS QUITE A BIT DIFFERENT FROM THE PREVIOUS
FORECAST THAT HAD A CHANCE OF PRECIP JUST ABOUT EVERYWHERE. AFTER
THE TROUGH PASSES MONDAY ANOTHER BROAD RIDGE SETS UP ACROSS THE
INLAND NORTHWEST. THE BEST CHANCE OF PRECIP WILL REMAIN ACROSS
SOUTHEAST WA AND THE LC VALLEY/CAMAS PRAIRIE AREAS. TEMPERATURES
WILL START TO MODERATE A BIT, BUT WILL STILL BE BELOW AVERAGE FOR
THIS TIME OF THE YEAR. /NISBET

&&

.AVIATION...
00Z TAFS: A VERY MOIST BOUNDARY LAYER WILL PROMOTE WIDESPREAD IFR
AND LIFR CEILINGS AND VISIBILITIES OVER THE COLUMBIA BASIN THROUGH
06Z...AFFECTING ALL TAF SITES EXCEPT KPUW AND KLWS. AFTER 06Z A
DEVELOPING SURFACE LOW OVER BRITISH COLUMBIA WILL CREATE A
SOUTHERLY GRADIENT BREEZE WHICH MAY ALLOW SOME IMPROVEMENT IN
VISIBILITIES AND MARGINAL CEILING IMPROVEMENT...HOWEVER SINCE THIS
WILL BE DEVELOPING AT NIGHT AND THUS INVOLVING A NOCTURNAL
INVERSION LOCKING IN THE LOW LEVEL MOISTURE...CONFIDENCE IS ONLY
MODERATE FOR THIS IMPROVEMENT. CONFIDENCE IS HIGHER FOR
SIGNIFICANT IMPROVEMENT DURING THE MID MORNING HOURS ON THURSDAY
WHEN DIURNAL MIXING WILL PLAY A LARGER ROLE IN BREAKING UP THE FOG
AND STRATUS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SPOKANE        39  49  41  46  27  30 /  30  30  20  70  60  10
COEUR D`ALENE  36  47  41  45  29  31 /  30  40  40  80  70  20
PULLMAN        44  52  43  49  32  34 /  20  30  30  90  90  50
LEWISTON       43  55  46  53  38  40 /  10  10  20  60  70  60
COLVILLE       36  45  40  43  22  24 /  60  50  50  70  30  10
SANDPOINT      33  45  38  42  26  26 /  70  60  70  80  80  20
KELLOGG        37  44  39  41  30  31 /  60  80  60  90 100  50
MOSES LAKE     38  52  41  51  27  31 /  10  10  20  30  30  10
WENATCHEE      39  47  41  48  29  30 /  10  10  30  30  20  10
OMAK           34  43  37  41  16  20 /  30  20  20  20  20  10

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
WA...DENSE FOG ADVISORY UNTIL 10 PM PST THIS EVENING FOR NORTHEAST
     MOUNTAINS-SPOKANE AREA-UPPER COLUMBIA BASIN-WATERVILLE
     PLATEAU.

&&

$$




000
FXUS66 KOTX 262343
AFDOTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
343 PM PST WED NOV 26 2014

.SYNOPSIS...
MILD AND BREEZY WEATHER IS EXPECTED TONIGHT AND THANKSGIVING WITH
AREAS OF DENSE FOG. SNOW LEVELS SHOULD RISE ABOVE THE MOUNTAIN
PASSES. MOTORISTS WITH PLANS TO TRAVEL OVER THE MOUNTAIN PASSES
SHOULD EXPERIENCE GOOD CONDITIONS THIS AFTERNOON THROUGH FRIDAY
AFTERNOON. THE ARRIVAL OF A COLD FRONT FRIDAY NIGHT INTO SATURDAY
WILL BRING WINTER DRIVING CONDITIONS TO THE MOUNTAIN PASSES AND
MUCH COOLER WEATHER FOR THE WEEKEND.

&&

.DISCUSSION...
TONIGHT AND THURSDAY: THE REGION REMAINS UNDER A DIRTY UPPER-LEVEL
RIDGE. IN GENERAL, THE RIDGE IS BRINGING MUCH WARMER AIR INTO THE
REGION (AT LEAST IN THE MIDLEVELS) AND IS SHOVING THE MOIST
FRONTAL BOUNDARY NORTHWARD INTO SOUTHERN BC. BECAUSE THE RIDGE HAS
FULLY TRANSLATED EAST, SOME OF THIS MOISTURE IS COMING DOWN THE
EASTERN PERIPHERY OF THE RIDGE AND CONTINUING TO BRING LIGHT RAIN
AND HIGH MOUNTAIN SNOW INTO THE NORTHERN IDAHO PANHANDLE. THE
BIGGEST IMPACTS FROM THE WARMING ALOFT IS A MOIST INVERSION OVER
THE BASIN DELIVERING WIDESPREAD FOG AND LOW CLOUDS. DENSE FOG HAS
PLAGUED THE UPPER COLUMBIA BASIN THROUGH MUCH OF THE DAY AND WILL
CONTINUE FOR MUCH OF THE NIGHT. AS OF 2PM...THE WORSE VISIBILITIES
WERE FOUND ALONG HWY 2 FROM AIRWAY HEIGHTS TO WATERVILLE AND
NORTHWARD ALONG HWY 395 BETWEEN SPOKANE AND COLVILLE. AS SUCH, A
DENSE FOG ADVISORY HAS BEEN ISSUED.

AS WE GO INTO THE NIGHT AND THANKSGIVING, THE RIDGE WILL FLATTEN
AND THE MOIST FRONTAL BOUNDARY WILL SAG BACK INTO WASHINGTON AND
NORTHERN IDAHO. WE WILL NOT SEE MUCH IN THE WAY OF COOLING NORTH
OF THE BOUNDARY BUT RATHER AN INCREASE IN PRECIPITATION. THE GOOD
NEWS IS WINDS SHOULD BEGIN PICKING UP AND WE WILL LOSE THE POCKETS
OF COOLER AIR IN THE NORTHERN VALLEYS RESULTING IN SNOW LEVELS
BETWEEN 5-6K FT. MODEST WESTERLY FLOW WITHIN THE 850-700MB LAYER
WILL DELIVER SOMEWHAT OF A RAIN SHADOW IN THE BASIN BUT ADD LIFT
TO THE ALREADY STRONG ISENTROPIC OMEGA OVER THE NORTHERN AND
EASTERN MOUNTAINS.

UNDER THIS PATTERN, A WIDE RANGE OF TEMPERATURES WILL BE FOUND
ACROSS THE REGION. TODAY FOR INSTANCE, WE ARE SEEING HIGHS IN THE
30`S NORTH TO 60`S IN THE FOOTHILLS OF THE BLUE MTNS. OVERNIGHT
LOWS WILL DROP VERY LITTLE FROM THE CURRENT READINGS (WITH THE
EXCEPTION OF THE 60`S IN THE SOUTHEAST) THEN TOMORROW WILL HAVE
THE POTENTIAL FOR WIDESPREAD 40S AND 50S WITH A FEW 60`S IF THE
WINDS CAN EFFICIENCY MIX TO THE VALLEY FLOORS.  /SB

THURSDAY NIGHT THROUGH SATURDAY...A COMPLEX INTERPLAY BETWEEN AN
INITIALLY VERY MOIST AIR MASS AND A STRONG ARCTIC PUSH WILL BRING
A VERY ACTIVE WEATHER REGIME TO THE REGION THROUGH THIS
PERIOD...FEATURING WET AND WINDY BUT SURPRISINGLY MILD LATE
NOVEMBER CONDITIONS THURSDAY NIGHT THROUGH FRIDAY NIGHT...WITH A
STARK DRYING TREND WITH TEMPERATURES BEGINNING TO PLUNGE LIKE A
ROCK ON SATURDAY.

TWO FEATURES OF NOTE ON PACIFIC SATELLITE ARE THE DEEP CLOSED LOW
SPINNING OFF THE COAST...HOSTING A VERY MOIST AIR MASS...AND AN
INCIPIENT ARCTIC ORIGIN TROUGH BARELY PERCEPTIBLE ON SATELLITE
OVER THE YUKON DROPPING INTO NORTHERN BC THIS AFTERNOON. THE
LATEST GFS AND ECMWF MODELS ARE IN BETTER AGREEMENT TODAY AND
HONING IN ON A SOLUTION THAT INVOLVES THE DIGGING ARCTIC TROUGH
PICKING UP AND ENHANCING THE PACIFIC MOISTURE OVER THE FORECAST
AREA INTO A LONG RUNNING SEMI-OROGRAPHIC PRECIPITATION PATTERN
FOLLOWED BY A STRONG PUSH OF VERY DRY ARCTIC AIR DOWN THE OKANOGAN
VALLEY AND EVENTUALLY EXCHANGING THE CURRENT MOIST MARITIME AIR
MASS OVER THE REGION WITH A BONE DRY AND COLD AIR MASS.

THURSDAY NIGHT WILL INCLUDE A MOIST OROGRAPHIC PATTERN WITH
STRONG WESTERLY FLOW ACROSS THE MOUNTAINS PROMOTING A DECENT RAIN
SHADOW OVER THE BASIN...WITH SNOW LEVELS IN THIS MILD MARITIME
AIR MASS MAINTAINING BETWEEN 5000 AND 6000 FEET. ON FRIDAY A DEEP
SURFACE LOW PRESSURE WILL FORM TO THE NORTH AND DEEPEN
AGGRESSIVELY UNDER THE DYNAMIC JET REGION AHEAD OF THE INCOMING
TROUGH AS IT DESCENDS THROUGH THE FORECAST AREA. THIS WILL ALLOW
RAIN AND HIGH MOUNTAIN SNOW TO BECOME MORE WIDESPREAD AND INCLUDE
MOST OF THE COLUMBIA BASIN DURING THE DAY FRIDAY. WINDS WILL
BECOME VERY GUSTY DURING FRIDAY AFTERNOON ESPECIALLY OVER THE
EXPOSED BASIN TERRAIN...AND A WIND ADVISORY MAY BE NECESSARY WITH
MODEL SOUNDINGS SUGGESTING 45 TO 50 MPH GUST POTENTIAL IN THE
MIXED LAYER. THIS WILL ALSO PROMOTE CONTINUED MILD TEMPERATURES.

FRIDAY NIGHT THE ARCTIC COLD FRONT WILL FOLLOW THE NOW EXITING
SURFACE LOW WITH AN IMPRESSIVELY STRONG NORTHERLY GRADIENT SETTING
UP DOWN THE OKANOGAN VALLEY AND EVENTUALLY ENCOMPASSING THE DEEP
BASIN BY SATURDAY. THIS IS ANOTHER POTENTIAL WIND ADVISORY OR
EVEN A HIGH WIND WARNING PATTERN THAT WILL NEED TO BE MONITORED
AND REFINED ON SUBSEQUENT SHIFTS. BY SATURDAY AFTERNOON A STARK
CLEARING TREND FROM NORTH TO SOUTH WILL BECOME APPARENT AS VERY
DRY AIR INVADES THE REGION. AS SNOW LEVELS QUICKLY DROP
PRECIPITATION WILL BE QUICKLY ENDING SO NO WINTER STORM HIGHLIGHTS
ARE EXPECTED. TEMPERATURES ON SATURDAY MAY START OUT AT THEIR
HIGH TEMPERATURES AND EITHER REMAIN STEADY OR PLUNGE DURING THE
DAY. /FUGAZZI

SATURDAY NIGHT THROUGH SUNDAY NIGHT: A TROUGH WILL EXIT THE
REGION SATURDAY NIGHT WITH THE BEST CHANCE OF SNOW EXTENDING FROM
PULLMAN SOUTH TOWARD THE BLUE MOUNTAINS AND CAMAS PRAIRIE. THE
FLOW WILL TURN NORTH TO NORTHEASTERLY WHICH WILL BRING IN COLD
CANADIAN AIR. MIN TEMPERATURES WILL BE ABOUT 7-14 DEGREES BELOW
AVERAGE FOR THIS TIME OF THE YEAR. TEMPS IN THE SINGLE DIGITS TO
LOW TEENS WILL BE COMMON. BELOW ZERO IS NOT OUT OF THE QUESTION
FOR THE METHOW AND OKANOGAN VALLEYS. SUNDAY AND SUNDAY NIGHT THE
MODELS AGREE ON SHOWING A BROAD RIDGE IN PLACE WITH VERY DRY
CONDITIONS. HAVE TAKEN OUT ALL PREVIOUS MENTION OF SNOW AND
DECREASED SKY COVER. THERE IS THE POTENTIAL FOR VALLEY FOG, BUT AM
NOT CONFIDENT QUITE YET AS TO WHERE IT WOULD FORM. WILL HAVE TO
WAIT TO SEE HOW MUCH DRYING WE GET BEHIND THE TROUGH.

MONDAY THROUGH WEDNESDAY: BOTH THE EC AND GFS SHOW ANOTHER TROUGH
MOVING THROUGH THE AREA ON MONDAY. THERE ARE SOME DISCREPANCIES
BETWEEN THE TWO...MAINLY BEING THE GFS TAKES THE MAIN ENERGY AND
SLIDES IT ALONG THE CANADIAN BORDER WHERE THE EC DIGS IT FURTHER
SOUTH INTO OUR AREA. SO WE HAVE SOME DISCREPANCIES AS TO WHERE THE
BEST CHANCE OF RAIN AND SNOW WILL SET UP. RIGHT NOW AM TRENDING
MORE TOWARDS THE WETTER/SLIGHTLY WARMER GFS AND HAVE CHANCE OF
PRECIPITATION ACROSS EXTREME EASTERN WA AND ALL OF THE ID
PANHANDLE. THIS IS QUITE A BIT DIFFERENT FROM THE PREVIOUS
FORECAST THAT HAD A CHANCE OF PRECIP JUST ABOUT EVERYWHERE. AFTER
THE TROUGH PASSES MONDAY ANOTHER BROAD RIDGE SETS UP ACROSS THE
INLAND NORTHWEST. THE BEST CHANCE OF PRECIP WILL REMAIN ACROSS
SOUTHEAST WA AND THE LC VALLEY/CAMAS PRAIRIE AREAS. TEMPERATURES
WILL START TO MODERATE A BIT, BUT WILL STILL BE BELOW AVERAGE FOR
THIS TIME OF THE YEAR. /NISBET

&&

.AVIATION...
00Z TAFS: A VERY MOIST BOUNDARY LAYER WILL PROMOTE WIDESPREAD IFR
AND LIFR CEILINGS AND VISIBILITIES OVER THE COLUMBIA BASIN THROUGH
06Z...AFFECTING ALL TAF SITES EXCEPT KPUW AND KLWS. AFTER 06Z A
DEVELOPING SURFACE LOW OVER BRITISH COLUMBIA WILL CREATE A
SOUTHERLY GRADIENT BREEZE WHICH MAY ALLOW SOME IMPROVEMENT IN
VISIBILITIES AND MARGINAL CEILING IMPROVEMENT...HOWEVER SINCE THIS
WILL BE DEVELOPING AT NIGHT AND THUS INVOLVING A NOCTURNAL
INVERSION LOCKING IN THE LOW LEVEL MOISTURE...CONFIDENCE IS ONLY
MODERATE FOR THIS IMPROVEMENT. CONFIDENCE IS HIGHER FOR
SIGNIFICANT IMPROVEMENT DURING THE MID MORNING HOURS ON THURSDAY
WHEN DIURNAL MIXING WILL PLAY A LARGER ROLE IN BREAKING UP THE FOG
AND STRATUS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SPOKANE        39  49  41  46  27  30 /  30  30  20  70  60  10
COEUR D`ALENE  36  47  41  45  29  31 /  30  40  40  80  70  20
PULLMAN        44  52  43  49  32  34 /  20  30  30  90  90  50
LEWISTON       43  55  46  53  38  40 /  10  10  20  60  70  60
COLVILLE       36  45  40  43  22  24 /  60  50  50  70  30  10
SANDPOINT      33  45  38  42  26  26 /  70  60  70  80  80  20
KELLOGG        37  44  39  41  30  31 /  60  80  60  90 100  50
MOSES LAKE     38  52  41  51  27  31 /  10  10  20  30  30  10
WENATCHEE      39  47  41  48  29  30 /  10  10  30  30  20  10
OMAK           34  43  37  41  16  20 /  30  20  20  20  20  10

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
WA...DENSE FOG ADVISORY UNTIL 10 PM PST THIS EVENING FOR NORTHEAST
     MOUNTAINS-SPOKANE AREA-UPPER COLUMBIA BASIN-WATERVILLE
     PLATEAU.

&&

$$




000
FXUS66 KOTX 262343
AFDOTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
343 PM PST WED NOV 26 2014

.SYNOPSIS...
MILD AND BREEZY WEATHER IS EXPECTED TONIGHT AND THANKSGIVING WITH
AREAS OF DENSE FOG. SNOW LEVELS SHOULD RISE ABOVE THE MOUNTAIN
PASSES. MOTORISTS WITH PLANS TO TRAVEL OVER THE MOUNTAIN PASSES
SHOULD EXPERIENCE GOOD CONDITIONS THIS AFTERNOON THROUGH FRIDAY
AFTERNOON. THE ARRIVAL OF A COLD FRONT FRIDAY NIGHT INTO SATURDAY
WILL BRING WINTER DRIVING CONDITIONS TO THE MOUNTAIN PASSES AND
MUCH COOLER WEATHER FOR THE WEEKEND.

&&

.DISCUSSION...
TONIGHT AND THURSDAY: THE REGION REMAINS UNDER A DIRTY UPPER-LEVEL
RIDGE. IN GENERAL, THE RIDGE IS BRINGING MUCH WARMER AIR INTO THE
REGION (AT LEAST IN THE MIDLEVELS) AND IS SHOVING THE MOIST
FRONTAL BOUNDARY NORTHWARD INTO SOUTHERN BC. BECAUSE THE RIDGE HAS
FULLY TRANSLATED EAST, SOME OF THIS MOISTURE IS COMING DOWN THE
EASTERN PERIPHERY OF THE RIDGE AND CONTINUING TO BRING LIGHT RAIN
AND HIGH MOUNTAIN SNOW INTO THE NORTHERN IDAHO PANHANDLE. THE
BIGGEST IMPACTS FROM THE WARMING ALOFT IS A MOIST INVERSION OVER
THE BASIN DELIVERING WIDESPREAD FOG AND LOW CLOUDS. DENSE FOG HAS
PLAGUED THE UPPER COLUMBIA BASIN THROUGH MUCH OF THE DAY AND WILL
CONTINUE FOR MUCH OF THE NIGHT. AS OF 2PM...THE WORSE VISIBILITIES
WERE FOUND ALONG HWY 2 FROM AIRWAY HEIGHTS TO WATERVILLE AND
NORTHWARD ALONG HWY 395 BETWEEN SPOKANE AND COLVILLE. AS SUCH, A
DENSE FOG ADVISORY HAS BEEN ISSUED.

AS WE GO INTO THE NIGHT AND THANKSGIVING, THE RIDGE WILL FLATTEN
AND THE MOIST FRONTAL BOUNDARY WILL SAG BACK INTO WASHINGTON AND
NORTHERN IDAHO. WE WILL NOT SEE MUCH IN THE WAY OF COOLING NORTH
OF THE BOUNDARY BUT RATHER AN INCREASE IN PRECIPITATION. THE GOOD
NEWS IS WINDS SHOULD BEGIN PICKING UP AND WE WILL LOSE THE POCKETS
OF COOLER AIR IN THE NORTHERN VALLEYS RESULTING IN SNOW LEVELS
BETWEEN 5-6K FT. MODEST WESTERLY FLOW WITHIN THE 850-700MB LAYER
WILL DELIVER SOMEWHAT OF A RAIN SHADOW IN THE BASIN BUT ADD LIFT
TO THE ALREADY STRONG ISENTROPIC OMEGA OVER THE NORTHERN AND
EASTERN MOUNTAINS.

UNDER THIS PATTERN, A WIDE RANGE OF TEMPERATURES WILL BE FOUND
ACROSS THE REGION. TODAY FOR INSTANCE, WE ARE SEEING HIGHS IN THE
30`S NORTH TO 60`S IN THE FOOTHILLS OF THE BLUE MTNS. OVERNIGHT
LOWS WILL DROP VERY LITTLE FROM THE CURRENT READINGS (WITH THE
EXCEPTION OF THE 60`S IN THE SOUTHEAST) THEN TOMORROW WILL HAVE
THE POTENTIAL FOR WIDESPREAD 40S AND 50S WITH A FEW 60`S IF THE
WINDS CAN EFFICIENCY MIX TO THE VALLEY FLOORS.  /SB

THURSDAY NIGHT THROUGH SATURDAY...A COMPLEX INTERPLAY BETWEEN AN
INITIALLY VERY MOIST AIR MASS AND A STRONG ARCTIC PUSH WILL BRING
A VERY ACTIVE WEATHER REGIME TO THE REGION THROUGH THIS
PERIOD...FEATURING WET AND WINDY BUT SURPRISINGLY MILD LATE
NOVEMBER CONDITIONS THURSDAY NIGHT THROUGH FRIDAY NIGHT...WITH A
STARK DRYING TREND WITH TEMPERATURES BEGINNING TO PLUNGE LIKE A
ROCK ON SATURDAY.

TWO FEATURES OF NOTE ON PACIFIC SATELLITE ARE THE DEEP CLOSED LOW
SPINNING OFF THE COAST...HOSTING A VERY MOIST AIR MASS...AND AN
INCIPIENT ARCTIC ORIGIN TROUGH BARELY PERCEPTIBLE ON SATELLITE
OVER THE YUKON DROPPING INTO NORTHERN BC THIS AFTERNOON. THE
LATEST GFS AND ECMWF MODELS ARE IN BETTER AGREEMENT TODAY AND
HONING IN ON A SOLUTION THAT INVOLVES THE DIGGING ARCTIC TROUGH
PICKING UP AND ENHANCING THE PACIFIC MOISTURE OVER THE FORECAST
AREA INTO A LONG RUNNING SEMI-OROGRAPHIC PRECIPITATION PATTERN
FOLLOWED BY A STRONG PUSH OF VERY DRY ARCTIC AIR DOWN THE OKANOGAN
VALLEY AND EVENTUALLY EXCHANGING THE CURRENT MOIST MARITIME AIR
MASS OVER THE REGION WITH A BONE DRY AND COLD AIR MASS.

THURSDAY NIGHT WILL INCLUDE A MOIST OROGRAPHIC PATTERN WITH
STRONG WESTERLY FLOW ACROSS THE MOUNTAINS PROMOTING A DECENT RAIN
SHADOW OVER THE BASIN...WITH SNOW LEVELS IN THIS MILD MARITIME
AIR MASS MAINTAINING BETWEEN 5000 AND 6000 FEET. ON FRIDAY A DEEP
SURFACE LOW PRESSURE WILL FORM TO THE NORTH AND DEEPEN
AGGRESSIVELY UNDER THE DYNAMIC JET REGION AHEAD OF THE INCOMING
TROUGH AS IT DESCENDS THROUGH THE FORECAST AREA. THIS WILL ALLOW
RAIN AND HIGH MOUNTAIN SNOW TO BECOME MORE WIDESPREAD AND INCLUDE
MOST OF THE COLUMBIA BASIN DURING THE DAY FRIDAY. WINDS WILL
BECOME VERY GUSTY DURING FRIDAY AFTERNOON ESPECIALLY OVER THE
EXPOSED BASIN TERRAIN...AND A WIND ADVISORY MAY BE NECESSARY WITH
MODEL SOUNDINGS SUGGESTING 45 TO 50 MPH GUST POTENTIAL IN THE
MIXED LAYER. THIS WILL ALSO PROMOTE CONTINUED MILD TEMPERATURES.

FRIDAY NIGHT THE ARCTIC COLD FRONT WILL FOLLOW THE NOW EXITING
SURFACE LOW WITH AN IMPRESSIVELY STRONG NORTHERLY GRADIENT SETTING
UP DOWN THE OKANOGAN VALLEY AND EVENTUALLY ENCOMPASSING THE DEEP
BASIN BY SATURDAY. THIS IS ANOTHER POTENTIAL WIND ADVISORY OR
EVEN A HIGH WIND WARNING PATTERN THAT WILL NEED TO BE MONITORED
AND REFINED ON SUBSEQUENT SHIFTS. BY SATURDAY AFTERNOON A STARK
CLEARING TREND FROM NORTH TO SOUTH WILL BECOME APPARENT AS VERY
DRY AIR INVADES THE REGION. AS SNOW LEVELS QUICKLY DROP
PRECIPITATION WILL BE QUICKLY ENDING SO NO WINTER STORM HIGHLIGHTS
ARE EXPECTED. TEMPERATURES ON SATURDAY MAY START OUT AT THEIR
HIGH TEMPERATURES AND EITHER REMAIN STEADY OR PLUNGE DURING THE
DAY. /FUGAZZI

SATURDAY NIGHT THROUGH SUNDAY NIGHT: A TROUGH WILL EXIT THE
REGION SATURDAY NIGHT WITH THE BEST CHANCE OF SNOW EXTENDING FROM
PULLMAN SOUTH TOWARD THE BLUE MOUNTAINS AND CAMAS PRAIRIE. THE
FLOW WILL TURN NORTH TO NORTHEASTERLY WHICH WILL BRING IN COLD
CANADIAN AIR. MIN TEMPERATURES WILL BE ABOUT 7-14 DEGREES BELOW
AVERAGE FOR THIS TIME OF THE YEAR. TEMPS IN THE SINGLE DIGITS TO
LOW TEENS WILL BE COMMON. BELOW ZERO IS NOT OUT OF THE QUESTION
FOR THE METHOW AND OKANOGAN VALLEYS. SUNDAY AND SUNDAY NIGHT THE
MODELS AGREE ON SHOWING A BROAD RIDGE IN PLACE WITH VERY DRY
CONDITIONS. HAVE TAKEN OUT ALL PREVIOUS MENTION OF SNOW AND
DECREASED SKY COVER. THERE IS THE POTENTIAL FOR VALLEY FOG, BUT AM
NOT CONFIDENT QUITE YET AS TO WHERE IT WOULD FORM. WILL HAVE TO
WAIT TO SEE HOW MUCH DRYING WE GET BEHIND THE TROUGH.

MONDAY THROUGH WEDNESDAY: BOTH THE EC AND GFS SHOW ANOTHER TROUGH
MOVING THROUGH THE AREA ON MONDAY. THERE ARE SOME DISCREPANCIES
BETWEEN THE TWO...MAINLY BEING THE GFS TAKES THE MAIN ENERGY AND
SLIDES IT ALONG THE CANADIAN BORDER WHERE THE EC DIGS IT FURTHER
SOUTH INTO OUR AREA. SO WE HAVE SOME DISCREPANCIES AS TO WHERE THE
BEST CHANCE OF RAIN AND SNOW WILL SET UP. RIGHT NOW AM TRENDING
MORE TOWARDS THE WETTER/SLIGHTLY WARMER GFS AND HAVE CHANCE OF
PRECIPITATION ACROSS EXTREME EASTERN WA AND ALL OF THE ID
PANHANDLE. THIS IS QUITE A BIT DIFFERENT FROM THE PREVIOUS
FORECAST THAT HAD A CHANCE OF PRECIP JUST ABOUT EVERYWHERE. AFTER
THE TROUGH PASSES MONDAY ANOTHER BROAD RIDGE SETS UP ACROSS THE
INLAND NORTHWEST. THE BEST CHANCE OF PRECIP WILL REMAIN ACROSS
SOUTHEAST WA AND THE LC VALLEY/CAMAS PRAIRIE AREAS. TEMPERATURES
WILL START TO MODERATE A BIT, BUT WILL STILL BE BELOW AVERAGE FOR
THIS TIME OF THE YEAR. /NISBET

&&

.AVIATION...
00Z TAFS: A VERY MOIST BOUNDARY LAYER WILL PROMOTE WIDESPREAD IFR
AND LIFR CEILINGS AND VISIBILITIES OVER THE COLUMBIA BASIN THROUGH
06Z...AFFECTING ALL TAF SITES EXCEPT KPUW AND KLWS. AFTER 06Z A
DEVELOPING SURFACE LOW OVER BRITISH COLUMBIA WILL CREATE A
SOUTHERLY GRADIENT BREEZE WHICH MAY ALLOW SOME IMPROVEMENT IN
VISIBILITIES AND MARGINAL CEILING IMPROVEMENT...HOWEVER SINCE THIS
WILL BE DEVELOPING AT NIGHT AND THUS INVOLVING A NOCTURNAL
INVERSION LOCKING IN THE LOW LEVEL MOISTURE...CONFIDENCE IS ONLY
MODERATE FOR THIS IMPROVEMENT. CONFIDENCE IS HIGHER FOR
SIGNIFICANT IMPROVEMENT DURING THE MID MORNING HOURS ON THURSDAY
WHEN DIURNAL MIXING WILL PLAY A LARGER ROLE IN BREAKING UP THE FOG
AND STRATUS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SPOKANE        39  49  41  46  27  30 /  30  30  20  70  60  10
COEUR D`ALENE  36  47  41  45  29  31 /  30  40  40  80  70  20
PULLMAN        44  52  43  49  32  34 /  20  30  30  90  90  50
LEWISTON       43  55  46  53  38  40 /  10  10  20  60  70  60
COLVILLE       36  45  40  43  22  24 /  60  50  50  70  30  10
SANDPOINT      33  45  38  42  26  26 /  70  60  70  80  80  20
KELLOGG        37  44  39  41  30  31 /  60  80  60  90 100  50
MOSES LAKE     38  52  41  51  27  31 /  10  10  20  30  30  10
WENATCHEE      39  47  41  48  29  30 /  10  10  30  30  20  10
OMAK           34  43  37  41  16  20 /  30  20  20  20  20  10

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
WA...DENSE FOG ADVISORY UNTIL 10 PM PST THIS EVENING FOR NORTHEAST
     MOUNTAINS-SPOKANE AREA-UPPER COLUMBIA BASIN-WATERVILLE
     PLATEAU.

&&

$$




000
FXUS66 KOTX 262232
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
231 PM PST WED NOV 26 2014

.SYNOPSIS...
Mild and breezy weather is expected tonight and Thanksgiving with
areas of dense fog. Snow levels should rise above the mountain
passes. Motorists with plans to travel over the mountain passes
should experience good conditions this afternoon through Friday
afternoon. The arrival of a cold front Friday night into Saturday
will bring winter driving conditions to the mountain passes and
much cooler weather for the weekend.

&&

.DISCUSSION...
Tonight and Thursday: The region remains under a dirty upper-level
ridge. In general, the ridge is bringing much warmer air into the
region (at least in the midlevels) and is shoving the moist
frontal boundary northward into southern BC. Because the ridge has
not fully translated east, this moisture is coming down the
eastern periphery of the ridge and continuing to bring light rain
and high mountain snow into the northern Idaho Panhandle. A bigger
impact from the warming aloft is a moist inversion over the Basin
delivering widespread fog and low clouds. Dense fog has plagued
the Upper Columbia Basin through much of the day and will continue
for much of the night. As of 2PM...the worse visibilities were
found along Hwy 2 from Airway Heights to Waterville and northward
along Hwy 395 between Spokane and Colville. As such, a dense fog
advisory has been issued.

As we go into the night and Thanksgiving, the ridge will flatten
and the moist frontal boundary will sag back into Washington and
Northern Idaho. We will not see much in the way of cooling north
of the boundary but rather an increase in precipitation. The good
news is winds should begin picking up and we will lose the pockets
of cooler air in the northern valleys resulting in snow levels
between 5-6K ft. Modest westerly flow within the 850-700mb layer
will deliver somewhat of a rain shadow in the Basin but also add
lift to the already strong isentropic omega over the northern and
eastern mountains.

Under this pattern, a wide range of temperatures will be found
across the region. Today for instance, we are seeing highs in the
30`s north to 60`s in the foothills of the Blue Mtns. Overnight
lows will drop very little from the current readings (with the
exception of the 60`s in the southeast) then tomorrow will have
the potential for widespread 40s and 50s with a few 60`s if the
winds can efficiency mix to the valley floors.  /sb


&&

.AVIATION...
18Z TAFS: Recent rain/snow and warming aloft will promote areas
of fog and low clouds across most terminals this morning with
improving conditions expected through this evening. Areas of
LIFR/IFR fog currently stretches across the Upper Columbia Basin
from KCOE to KMWH. Confidence is low regarding exact timing for
improvements but gusty S/SW winds in the lower Basin should
promote improving conditions KPUW-KLWS by 20Z then expanding N
through 06z. KMWH/KEAT will carry the lower probabilities for
clearing. The upper-level ridge will flatten tomorrow suppressing
the moist frontal boundary back south lowering cigs btwn 4-6K ft
agl and incr the threat for light rain.  /sb





&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        39  49  41  46  27  30 /  30  30  20  70  60  10
Coeur d`Alene  36  47  41  45  29  31 /  30  40  40  80  70  20
Pullman        44  52  43  49  32  34 /  20  30  30  90  90  50
Lewiston       43  55  46  53  38  40 /  10  10  20  60  70  60
Colville       36  45  40  43  22  24 /  60  50  50  70  30  10
Sandpoint      33  45  38  42  26  26 /  70  60  70  80  80  20
Kellogg        37  44  39  41  30  31 /  60  80  60  90 100  50
Moses Lake     38  52  41  51  27  31 /  10  10  20  30  30  10
Wenatchee      39  47  41  48  29  30 /  10  10  30  30  20  10
Omak           34  43  37  41  16  20 /  30  20  20  20  20  10

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...Dense Fog Advisory until 10 PM PST this evening for Northeast
     Mountains-Spokane Area-Upper Columbia Basin-Waterville
     Plateau.

&&

$$




000
FXUS66 KOTX 262232
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
231 PM PST WED NOV 26 2014

.SYNOPSIS...
Mild and breezy weather is expected tonight and Thanksgiving with
areas of dense fog. Snow levels should rise above the mountain
passes. Motorists with plans to travel over the mountain passes
should experience good conditions this afternoon through Friday
afternoon. The arrival of a cold front Friday night into Saturday
will bring winter driving conditions to the mountain passes and
much cooler weather for the weekend.

&&

.DISCUSSION...
Tonight and Thursday: The region remains under a dirty upper-level
ridge. In general, the ridge is bringing much warmer air into the
region (at least in the midlevels) and is shoving the moist
frontal boundary northward into southern BC. Because the ridge has
not fully translated east, this moisture is coming down the
eastern periphery of the ridge and continuing to bring light rain
and high mountain snow into the northern Idaho Panhandle. A bigger
impact from the warming aloft is a moist inversion over the Basin
delivering widespread fog and low clouds. Dense fog has plagued
the Upper Columbia Basin through much of the day and will continue
for much of the night. As of 2PM...the worse visibilities were
found along Hwy 2 from Airway Heights to Waterville and northward
along Hwy 395 between Spokane and Colville. As such, a dense fog
advisory has been issued.

As we go into the night and Thanksgiving, the ridge will flatten
and the moist frontal boundary will sag back into Washington and
Northern Idaho. We will not see much in the way of cooling north
of the boundary but rather an increase in precipitation. The good
news is winds should begin picking up and we will lose the pockets
of cooler air in the northern valleys resulting in snow levels
between 5-6K ft. Modest westerly flow within the 850-700mb layer
will deliver somewhat of a rain shadow in the Basin but also add
lift to the already strong isentropic omega over the northern and
eastern mountains.

Under this pattern, a wide range of temperatures will be found
across the region. Today for instance, we are seeing highs in the
30`s north to 60`s in the foothills of the Blue Mtns. Overnight
lows will drop very little from the current readings (with the
exception of the 60`s in the southeast) then tomorrow will have
the potential for widespread 40s and 50s with a few 60`s if the
winds can efficiency mix to the valley floors.  /sb


&&

.AVIATION...
18Z TAFS: Recent rain/snow and warming aloft will promote areas
of fog and low clouds across most terminals this morning with
improving conditions expected through this evening. Areas of
LIFR/IFR fog currently stretches across the Upper Columbia Basin
from KCOE to KMWH. Confidence is low regarding exact timing for
improvements but gusty S/SW winds in the lower Basin should
promote improving conditions KPUW-KLWS by 20Z then expanding N
through 06z. KMWH/KEAT will carry the lower probabilities for
clearing. The upper-level ridge will flatten tomorrow suppressing
the moist frontal boundary back south lowering cigs btwn 4-6K ft
agl and incr the threat for light rain.  /sb





&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        39  49  41  46  27  30 /  30  30  20  70  60  10
Coeur d`Alene  36  47  41  45  29  31 /  30  40  40  80  70  20
Pullman        44  52  43  49  32  34 /  20  30  30  90  90  50
Lewiston       43  55  46  53  38  40 /  10  10  20  60  70  60
Colville       36  45  40  43  22  24 /  60  50  50  70  30  10
Sandpoint      33  45  38  42  26  26 /  70  60  70  80  80  20
Kellogg        37  44  39  41  30  31 /  60  80  60  90 100  50
Moses Lake     38  52  41  51  27  31 /  10  10  20  30  30  10
Wenatchee      39  47  41  48  29  30 /  10  10  30  30  20  10
Omak           34  43  37  41  16  20 /  30  20  20  20  20  10

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...Dense Fog Advisory until 10 PM PST this evening for Northeast
     Mountains-Spokane Area-Upper Columbia Basin-Waterville
     Plateau.

&&

$$





000
FXUS66 KOTX 262228
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
228 PM PST WED NOV 26 2014

.SYNOPSIS...
Mild and breezy weather is expected tonight and Thanksgiving with
areas of dense fog. Snow levels should rise above the mountain
passes. Motorists with plans to travel over the mountain passes
should experience good conditions this afternoon through Friday
afternoon. The arrival of a cold front Friday night into Saturday
will bring winter driving conditions to the mountain passes and
much cooler weather for the weekend.

&&

.DISCUSSION...
Tonight and Thursday: The region remains under a dirty upper-level
ridge. In general, the ridge is bringing much warmer air into the
region (at least in the midlevels) and is shoving the moist
frontal boundary northward into southern BC. Because the ridge has
fully translated east, some of this moisture is coming down the
eastern periphery of the ridge and continuing to bring light rain
and high mountain snow into the northern Idaho Panhandle. The
biggest impacts from the warming aloft is a moist inversion over
the Basin delivering widespread fog and low clouds. Dense fog has
plagued the Upper Columbia Basin through much of the day and will
continue for much of the night. As of 2PM...the worse visibilities
were found along Hwy 2 from Airway Heights to Waterville and
northward along Hwy 395 between Spokane and Colville. As such, a
dense fog advisory has been issued.

As we go into the night and Thanksgiving, the ridge will flatten
and the moist frontal boundary will sag back into Washington and
Northern Idaho. We will not see much in the way of cooling north
of the boundary but rather an increase in precipitation. The good
news is winds should begin picking up and we will lose the pockets
of cooler air in the northern valleys resulting in snow levels
between 5-6K ft. Modest westerly flow within the 850-700mb layer
will deliver somewhat of a rain shadow in the Basin but add lift
to the already strong isentropic omega over the northern and
eastern mountains.

Under this pattern, a wide range of temperatures will be found
across the region. Today for instance, we are seeing highs in the
30`s north to 60`s in the foothills of the Blue Mtns. Overnight
lows will drop very little from the current readings (with the
exception of the 60`s in the southeast) then tomorrow will have
the potential for widespread 40s and 50s with a few 60`s if the
winds can efficiency mix to the valley floors.  /sb

Thursday night through Saturday...A complex interplay between an
initially very moist air mass and a strong arctic push will bring
a very active weather regime to the region through this
period...featuring wet and windy but surprisingly mild late
November conditions Thursday night through Friday night...with a
stark drying trend with temperatures beginning to plunge like a
rock on Saturday.

Two features of note on Pacific satellite are the deep closed low
spinning off the coast...hosting a very moist air mass...and an
incipient arctic origin trough barely perceptible on satellite
over the Yukon dropping into northern BC this afternoon. The
latest GFS and ECMWF models are in better agreement today and
honing in on a solution that involves the digging arctic trough
picking up and enhancing the Pacific moisture over the forecast
area into a long running semi-orographic precipitation pattern
followed by a strong push of very dry arctic air down the Okanogan
Valley and eventually exchanging the current moist maritime air
mass over the region with a bone dry and cold air mass.

Thursday night will include a moist orographic pattern with
strong westerly flow across the mountains promoting a decent rain
shadow over the basin...with snow levels in this mild maritime
air mass maintaining between 5000 and 6000 feet. On Friday a deep
surface low pressure will form to the north and deepen
aggressively under the dynamic jet region ahead of the incoming
trough as it descends through the forecast area. This will allow
rain and high mountain snow to become more widespread and include
most of the Columbia Basin during the day Friday. Winds will
become very gusty during Friday afternoon especially over the
exposed basin terrain...and a Wind Advisory may be necessary with
model soundings suggesting 45 to 50 mph gust potential in the
mixed layer. This will also promote continued mild temperatures.

Friday night the arctic cold front will follow the now exiting
surface low with an impressively strong northerly gradient setting
up down the Okanogan Valley and eventually encompassing the deep
basin by Saturday. This is another potential Wind Advisory or
even a High Wind Warning pattern that will need to be monitored
and refined on subsequent shifts. By Saturday afternoon a stark
clearing trend from north to south will become apparent as very
dry air invades the region. As snow levels quickly drop
precipitation will be quickly ending so no winter storm highlights
are expected. Temperatures on Saturday may start out at their
high temperatures and either remain steady or plunge during the
day. /Fugazzi

Saturday Night through Sunday Night: A trough will exit the
region Saturday night with the best chance of snow extending from
Pullman south toward the Blue Mountains and Camas Prairie. The
flow will turn north to northeasterly which will bring in cold
Canadian air. Min temperatures will be about 7-14 degrees below
average for this time of the year. Temps in the single digits to
low teens will be common. Below zero is not out of the question
for the Methow and Okanogan Valleys. Sunday and Sunday Night the
models agree on showing a broad ridge in place with very dry
conditions. Have taken out all previous mention of snow and
decreased sky cover. There is the potential for valley fog, but am
not confident quite yet as to where it would form. Will have to
wait to see how much drying we get behind the trough.

Monday through Wednesday: Both the EC and GFS show another trough
moving through the area on Monday. There are some discrepancies
between the two...mainly being the GFS takes the main energy and
slides it along the Canadian border where the EC digs it further
south into our area. So we have some discrepancies as to where the
best chance of rain and snow will set up. Right now am trending
more towards the wetter/slightly warmer GFS and have chance of
precipitation across extreme eastern WA and all of the ID
Panhandle. This is quite a bit different from the previous
forecast that had a chance of precip just about everywhere. After
the trough passes Monday another broad ridge sets up across the
Inland Northwest. The best chance of precip will remain across
southeast WA and the LC Valley/Camas Prairie areas. Temperatures
will start to moderate a bit, but will still be below average for
this time of the year. /Nisbet

&&

.AVIATION...
18Z TAFS: Recent rain/snow and warming aloft will promote areas
of fog and low clouds across most terminals this morning with
improving conditions expected through this evening. Areas of
LIFR/IFR fog currently stretches across the Upper Columbia Basin
from KCOE to KMWH. Confidence is low regarding exact timing for
improvements but gusty S/SW winds in the lower Basin should
promote improving conditions KPUW-KLWS by 20Z then expanding N
through 06z. KMWH/KEAT will carry the lower probabilities for
clearing. The upper-level ridge will flatten tomorrow suppressing
the moist frontal boundary back south lowering cigs btwn 4-6K ft
agl and incr the threat for light rain.  /sb

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        39  49  41  46  27  30 /  30  30  20  70  60  10
Coeur d`Alene  36  47  41  45  29  31 /  30  40  40  80  70  20
Pullman        44  52  43  49  32  34 /  20  30  30  90  90  50
Lewiston       43  55  46  53  38  40 /  10  10  20  60  70  60
Colville       36  45  40  43  22  24 /  60  50  50  70  30  10
Sandpoint      33  45  38  42  26  26 /  70  60  70  80  80  20
Kellogg        37  44  39  41  30  31 /  60  80  60  90 100  50
Moses Lake     38  52  41  51  27  31 /  10  10  20  30  30  10
Wenatchee      39  47  41  48  29  30 /  10  10  30  30  20  10
Omak           34  43  37  41  16  20 /  30  20  20  20  20  10

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...Dense Fog Advisory until 10 PM PST this evening for Northeast
     Mountains-Spokane Area-Upper Columbia Basin-Waterville
     Plateau.

&&




000
FXUS66 KOTX 262228
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
228 PM PST WED NOV 26 2014

.SYNOPSIS...
Mild and breezy weather is expected tonight and Thanksgiving with
areas of dense fog. Snow levels should rise above the mountain
passes. Motorists with plans to travel over the mountain passes
should experience good conditions this afternoon through Friday
afternoon. The arrival of a cold front Friday night into Saturday
will bring winter driving conditions to the mountain passes and
much cooler weather for the weekend.

&&

.DISCUSSION...
Tonight and Thursday: The region remains under a dirty upper-level
ridge. In general, the ridge is bringing much warmer air into the
region (at least in the midlevels) and is shoving the moist
frontal boundary northward into southern BC. Because the ridge has
fully translated east, some of this moisture is coming down the
eastern periphery of the ridge and continuing to bring light rain
and high mountain snow into the northern Idaho Panhandle. The
biggest impacts from the warming aloft is a moist inversion over
the Basin delivering widespread fog and low clouds. Dense fog has
plagued the Upper Columbia Basin through much of the day and will
continue for much of the night. As of 2PM...the worse visibilities
were found along Hwy 2 from Airway Heights to Waterville and
northward along Hwy 395 between Spokane and Colville. As such, a
dense fog advisory has been issued.

As we go into the night and Thanksgiving, the ridge will flatten
and the moist frontal boundary will sag back into Washington and
Northern Idaho. We will not see much in the way of cooling north
of the boundary but rather an increase in precipitation. The good
news is winds should begin picking up and we will lose the pockets
of cooler air in the northern valleys resulting in snow levels
between 5-6K ft. Modest westerly flow within the 850-700mb layer
will deliver somewhat of a rain shadow in the Basin but add lift
to the already strong isentropic omega over the northern and
eastern mountains.

Under this pattern, a wide range of temperatures will be found
across the region. Today for instance, we are seeing highs in the
30`s north to 60`s in the foothills of the Blue Mtns. Overnight
lows will drop very little from the current readings (with the
exception of the 60`s in the southeast) then tomorrow will have
the potential for widespread 40s and 50s with a few 60`s if the
winds can efficiency mix to the valley floors.  /sb

Thursday night through Saturday...A complex interplay between an
initially very moist air mass and a strong arctic push will bring
a very active weather regime to the region through this
period...featuring wet and windy but surprisingly mild late
November conditions Thursday night through Friday night...with a
stark drying trend with temperatures beginning to plunge like a
rock on Saturday.

Two features of note on Pacific satellite are the deep closed low
spinning off the coast...hosting a very moist air mass...and an
incipient arctic origin trough barely perceptible on satellite
over the Yukon dropping into northern BC this afternoon. The
latest GFS and ECMWF models are in better agreement today and
honing in on a solution that involves the digging arctic trough
picking up and enhancing the Pacific moisture over the forecast
area into a long running semi-orographic precipitation pattern
followed by a strong push of very dry arctic air down the Okanogan
Valley and eventually exchanging the current moist maritime air
mass over the region with a bone dry and cold air mass.

Thursday night will include a moist orographic pattern with
strong westerly flow across the mountains promoting a decent rain
shadow over the basin...with snow levels in this mild maritime
air mass maintaining between 5000 and 6000 feet. On Friday a deep
surface low pressure will form to the north and deepen
aggressively under the dynamic jet region ahead of the incoming
trough as it descends through the forecast area. This will allow
rain and high mountain snow to become more widespread and include
most of the Columbia Basin during the day Friday. Winds will
become very gusty during Friday afternoon especially over the
exposed basin terrain...and a Wind Advisory may be necessary with
model soundings suggesting 45 to 50 mph gust potential in the
mixed layer. This will also promote continued mild temperatures.

Friday night the arctic cold front will follow the now exiting
surface low with an impressively strong northerly gradient setting
up down the Okanogan Valley and eventually encompassing the deep
basin by Saturday. This is another potential Wind Advisory or
even a High Wind Warning pattern that will need to be monitored
and refined on subsequent shifts. By Saturday afternoon a stark
clearing trend from north to south will become apparent as very
dry air invades the region. As snow levels quickly drop
precipitation will be quickly ending so no winter storm highlights
are expected. Temperatures on Saturday may start out at their
high temperatures and either remain steady or plunge during the
day. /Fugazzi

Saturday Night through Sunday Night: A trough will exit the
region Saturday night with the best chance of snow extending from
Pullman south toward the Blue Mountains and Camas Prairie. The
flow will turn north to northeasterly which will bring in cold
Canadian air. Min temperatures will be about 7-14 degrees below
average for this time of the year. Temps in the single digits to
low teens will be common. Below zero is not out of the question
for the Methow and Okanogan Valleys. Sunday and Sunday Night the
models agree on showing a broad ridge in place with very dry
conditions. Have taken out all previous mention of snow and
decreased sky cover. There is the potential for valley fog, but am
not confident quite yet as to where it would form. Will have to
wait to see how much drying we get behind the trough.

Monday through Wednesday: Both the EC and GFS show another trough
moving through the area on Monday. There are some discrepancies
between the two...mainly being the GFS takes the main energy and
slides it along the Canadian border where the EC digs it further
south into our area. So we have some discrepancies as to where the
best chance of rain and snow will set up. Right now am trending
more towards the wetter/slightly warmer GFS and have chance of
precipitation across extreme eastern WA and all of the ID
Panhandle. This is quite a bit different from the previous
forecast that had a chance of precip just about everywhere. After
the trough passes Monday another broad ridge sets up across the
Inland Northwest. The best chance of precip will remain across
southeast WA and the LC Valley/Camas Prairie areas. Temperatures
will start to moderate a bit, but will still be below average for
this time of the year. /Nisbet

&&

.AVIATION...
18Z TAFS: Recent rain/snow and warming aloft will promote areas
of fog and low clouds across most terminals this morning with
improving conditions expected through this evening. Areas of
LIFR/IFR fog currently stretches across the Upper Columbia Basin
from KCOE to KMWH. Confidence is low regarding exact timing for
improvements but gusty S/SW winds in the lower Basin should
promote improving conditions KPUW-KLWS by 20Z then expanding N
through 06z. KMWH/KEAT will carry the lower probabilities for
clearing. The upper-level ridge will flatten tomorrow suppressing
the moist frontal boundary back south lowering cigs btwn 4-6K ft
agl and incr the threat for light rain.  /sb

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        39  49  41  46  27  30 /  30  30  20  70  60  10
Coeur d`Alene  36  47  41  45  29  31 /  30  40  40  80  70  20
Pullman        44  52  43  49  32  34 /  20  30  30  90  90  50
Lewiston       43  55  46  53  38  40 /  10  10  20  60  70  60
Colville       36  45  40  43  22  24 /  60  50  50  70  30  10
Sandpoint      33  45  38  42  26  26 /  70  60  70  80  80  20
Kellogg        37  44  39  41  30  31 /  60  80  60  90 100  50
Moses Lake     38  52  41  51  27  31 /  10  10  20  30  30  10
Wenatchee      39  47  41  48  29  30 /  10  10  30  30  20  10
Omak           34  43  37  41  16  20 /  30  20  20  20  20  10

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...Dense Fog Advisory until 10 PM PST this evening for Northeast
     Mountains-Spokane Area-Upper Columbia Basin-Waterville
     Plateau.

&&





000
FXUS66 KPQR 262159
AFDPQR

FXUS66 KPQR DDHHMM
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
200 PM PST WED NOV 26 2014

.SYNOPSIS...A WEAK COLD FRONT OFF THE COAST WED AFTERNOON WILL PUSH
SLOWLY INLAND TONIGHT AND THU. THE FRONT WILL STALL OVER WESTERN
OREGON THU NIGHT AND FRI...THEN ANOTHER STRONGER COLD FRONT WILL
MOVE S THROUGH THE REGION FRI NIGHT USHERING COLDER WEATHER FOR THE
WEEKEND. HIGH PRES OVER THE INTERIOR NW WILL TURN THE FLOW OFFSHORE
BY SUN FOR DRY BUT COLD WEATHER. SUN NIGHT AND MON A SYSTEM COMING
UP FROM THE S WILL ATTEMPT TO SPREAD SOME PRECIPITATION UP OVER THE
COLD AIR MASS LEFT OVER FROM THE WEEKEND.
&&

.SHORT TERM...A WEAK COLD FRONT WAS OFFSHORE WED AFTERNOON...WITH
LAYERED CLOUDS SPREAD OUT AHEAD OF THE FRONT OVER THE PACIFIC NW. AS
THE UPPER RIDGE OVER THE REGION SHIFTS E TONIGHT AND THU THE FLOW
WILL TURN MORE TO THE SW...WITH THE FRONT SLOWLY PUSHING INLAND.
MODEL SOUNDINGS AGREE IN SHOWING MOISTURE INITIALLY IN THEMID AND
HIGH LEVELS...ABOVE 700MB. BY LATE TONIGHT THOUGH MOISTURE BEGINS TO
SPREAD IN IN THE LOWER LEVELS. DYNAMICS WITH THIS FRONT HOWEVER ON
THE WEAK SIDE...SO WILL BE SLOW TO INCREASE POPS OVERNIGHT INLAND
AREAS...WHILE THE COAST AND COAST RANGE WILL BENEFIT FROM AN
INCREASING LOW LEVEL SSW FLOW. WITH CLOUDS LIMITING RADIATIONAL
COOLING TONIGHT AND MUCH OF THE AREA STILL IN THE WARM SECTOR...
SHOULD BE ANOTHER UNSEASONABLY MILD NIGHT. THU THE FRONT APPEARS TO
STALL OVER THE REGION AS THE LOW OFFSHORE DIGS IN A BIT MORE. WITH
BAROCLINIC ZONE STALLED AND LOW LEVEL FLOW A LITTLE MORE ONSHORE
WILL TAKE POPS BACK UP TO LIKELY TO CATEGORICAL FOR MOST OF THE
REGION. ALTHOUGH THERE IS ONLY MODEST COOLING TO AIR MASS WITH THE
FRONT...CLOUDS AND EXPECTED OCCASIONAL LIGHT RAIN WILL LIMIT HIGH
TEMPS TO THE 50S MOST LOW ELEVATION AREAS.

LATE THU NIGHT...AND ESP FRI BETTER MOISTURE ARRIVES AS A NORTHERN
STREAM SHORT WAVE DROPS DOWN THROUGH BC WITH A TRUE COLD FRONT
DROPPING DOWN THE COAST AHEAD OF IT. MOIST ISENTROPIC LIFT IN THE
LOWER LEVELS IMPROVES AHEAD OF THE COLD FRONT AS WELL...BEST
DEPICTED IN MODEL 290K ISENTROPIC FIELDS. AS SUCH...POTENTIAL FOR
RAIN PICKS UP CONSIDERABLY BY FRI.

MODELS IN RELATIVELY GOOD AGREEMENT IN DEPICTING THE WESTERN
CANADIAN TROUGH DIGGING DOWN INTO THE PACIFIC NW STATES FRI NIGHT
AND SAT. ALL MODELS AT THIS POINT SHOWING A VIGOROUS CONTINENTAL
TYPE COLD FRONT MOVING S THROUGH SW WA AND NW OREGON FRI NIGHT.
PATTERN IS REMINISCENT OF A COLD FRONT FROM BACK ON 19 NOVEMBER 2003
THAT BROUGHT LOW ELEVATION SNOW TO INTERIOR N PARTS OF THE FORECAST
AREA. KEYS TO DOING SOMETHING SIMILAR RELY ON SOME OF THE
PRECIPITATION FALLING OVER AND BEHIND THE FRONT AS WELL AS STRONG
FRONTOGENETIC FORCING TO ALLOW FOR DYNAMIC COOLING. MODEL SOUNDINGS
AT THIS POINT INDICATE SNOW LEVEL FALLING RAPIDLY BEHIND THE FRONT
FRI NIGHT SUGGESTING AT LEAST A MIX OF RAIN AND SNOW POSSIBLE DOWN
TO FAIRLY LOW LEVELS. WHETHER IT WOULD BE COLD ENOUGH TO MIX SNOW AT
LOWEST ELEVATIONS IS ANYBODYS GUESS AT THIS POINT...BUT GIVEN THE
AGREEMENT IN MODELS AT THIS POINT WILL CARRY A MENTION OF MIXED RAIN
AND SNOW POSSIBLE FOR THE N PART OF THE AREA FRI NIGHT. SAT SEES A
RATHER COLD AIR MASS SETTLING IN OVER THE REGION BEHIND THE FRONT...
WITH A LINGERING CHANCE FOR SHOWERS...POTENTIALLY MIXED WITH SNOW IN
THE N...AS THE UPPER TROUGH MOVES THROUGH.

.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY...MOST GUIDANCE
SUGGESTS THE UPPER TROUGH AXIS RESPONSIBLE FOR SATURDAYS MIXED
RAIN/SNOW SHOWERS WILL BE MOVING ACROSS THE CASCADES SAT NIGHT...
WITH ANY LINGERING SNOW SHOWERS COMING TO END OVERNIGHT. EXPECT SOME
CLEARING SAT NIGHT AS COLD HIGH PRESSURE BUILDS DOWN FROM BRITISH
COLUMBIA...WITH LOW TEMPS LIKELY GETTING WELL INTO THE 20S FOR MOST
SPOTS. WITH HIGH PRESSURE STRENGTHENING EAST OF THE CASCADES...
EXPECT STRONG EAST WINDS TO RAMP UP THROUGH THE GORGE SUNDAY MORNING
AND PERSIST FOR MUCH OF THE PERIOD THROUGH WEDNESDAY...WITH BREEZY
CONDITIONS SPILLING INTO THE PORTLAND/VANCOUVER METRO. MONDAY MAY BE
A BRIEF BREAK FROM THE WINDS AS A SYSTEM PASSES BY TO OUR NORTH.

MEANWHILE...A DISTURBANCE FROM THE ALEUTIANS IS EXPECTED TO CUT OFF
FROM THE MAIN PACIFIC JET AND SETTLE OFF THE CALIFORNIA COAST BY
SUNDAY...WHERE IT WILL LIKELY LINGER FOR A COUPLE DAYS. THERE IS A
CHANCE THIS SYSTEM COULD COME CLOSE ENOUGH TO SPREAD SOME PRECIP
NORTHWARD INTO OUR FORECAST AREA SUN NIGHT OR MON. THE 12Z GFS AND
CANADIAN MODELS ARE MORE AGGRESSIVE WITH THIS THAN THE ECMWF. IF
THIS OCCURS...THERE MAY BE SOME LIGHT FREEZING RAIN IN PORTIONS OF
THE WILLAMETTE VALLEY WITH SOME SNOW OR LIGHT FREEZING RAIN IN THE
GORGE. CUTOFF LOWS SUCH AS THIS ONE ARE NOTORIOUSLY DIFFICULT TO
FORECAST...AS MODELS STRUGGLE WITH THEM IN THE EXTENDED FORECAST
PERIOD. WHERE THIS UPPER LOW GOES WILL DICTATE THE WEATHER THROUGH
MIDWEEK...BUT TEMPS ARE EXPECTED TO SLOWLY MODERATE TUESDAY AND
WEDNESDAY.  WEAGLE
&&

.AVIATION...GENERALLY VFR ACROSS THE AREA EARLY THIS AFTERNOON
EXCEPT FOR AREAS OF IFR ALONG THE COAST FROM KAST TO KHQM. EXPECT
VFR TO PREVAIL THROUGH AT LEAST THE EVENING HOURS. CIGS LOWER
ALONG THE COAST AFTER 03Z THU AS A COLD FRONT APPROACHES. LOOK FOR
CONDITIONS ALONG THE COAST TO FALL INTO MVFR BETWEEN 04Z TO 06Z
WITH PRECIP INCREASING OVERNIGHT. VFR SHOULD HOLD OVER THE INLAND
AREAS THROUGH AT LEAST 12Z THU...THEN MVFR CONDITIONS
INCREASE...WITH HIGHER TERRAIN BECOMING OBSCURED. CONSIDERABLE
LOW-LEVEL MOISTURE RESIDES OVER THE AREA THU WHICH WILL LEAD TO
WIDESPREAD MVFR OR WORSE CONDITIONS.

KPDX AND APPROACHES...VFR CONDITIONS TO PREVAIL THROUGH AT LEAST
12Z THU. RAIN DEVELOPS OVER WRN APPROACHES AROUND 10Z THEN SPREADS
E THEREAFTER...WITH LOCALIZED MVFR DEVELOPING AFTER 13Z.
INCREASING MVFR OR WORSE CONDITIONS THU MORNING THROUGH THE
AFTERNOON. WEISHAAR

&&

.MARINE...WIND SPEEDS EARLY THIS AFTERNOON STILL AT 15 TO 20 KT
WITH GUSTS UP TO 25 KT. EXPECT SPEEDS TO RAMP UP LATER THIS
AFTERNOON AHEAD OF AN APPROACHING FRONTAL SYSTEM. SHOULD SEE GALE
FORCE WIND GUSTS OVER MUCH OF THE WATERS BY LATE THIS AFTERNOON...
BUT MORE SO THIS EVENING AND OVERNIGHT. ALTHOUGH NOT A CLASSIC
CASE...SOME MODEL GUIDANCE IS SUGGESTING THE POTENTIAL FOR MINOR
COASTAL JET ENHANCEMENT WITHIN 20 NM. COULD SEE SOME GUSTS UP TO
40 KT IF THIS OCCURS. HIGH-END SMALL CRAFT ADVISORY SPEEDS PERSIST
THU MORNING. LATEST MODEL RUNS SHOW 20-25 KT NW-N WIND DEVELOPING
OVER THE N WATERS FRI EVENING THEN SPREADING FURTHER S OVERNIGHT
AS A STRONG COLD FRONT DROPS SOUTH OUT OF CANADA. THE WIND TURNS
OFFSHORE SAT WITH POTENTIAL GUSTS 20 TO 30 KT NEAR GAPS IN THE
COASTAL TERRAIN. WIND SPEEDS RELAX SUN.

SEAS EXPECTED TO BUILD TO 10 FT THIS EVENING THEN REMAIN AT OR
ABOVE 10 FT THROUGH AT LEAST SAT MORNING. WAVE HEIGHTS DROP OFF
SAT AFTERNOON AS OFFSHOR FLOW DEVELOPS. WEISHAAR

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 PM PST THIS AFTERNOON FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     GALE WARNING FROM 4 PM THIS AFTERNOON TO 4 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 4 PM THIS
     AFTERNOON TO 4 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 262159
AFDPQR

FXUS66 KPQR DDHHMM
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
200 PM PST WED NOV 26 2014

.SYNOPSIS...A WEAK COLD FRONT OFF THE COAST WED AFTERNOON WILL PUSH
SLOWLY INLAND TONIGHT AND THU. THE FRONT WILL STALL OVER WESTERN
OREGON THU NIGHT AND FRI...THEN ANOTHER STRONGER COLD FRONT WILL
MOVE S THROUGH THE REGION FRI NIGHT USHERING COLDER WEATHER FOR THE
WEEKEND. HIGH PRES OVER THE INTERIOR NW WILL TURN THE FLOW OFFSHORE
BY SUN FOR DRY BUT COLD WEATHER. SUN NIGHT AND MON A SYSTEM COMING
UP FROM THE S WILL ATTEMPT TO SPREAD SOME PRECIPITATION UP OVER THE
COLD AIR MASS LEFT OVER FROM THE WEEKEND.
&&

.SHORT TERM...A WEAK COLD FRONT WAS OFFSHORE WED AFTERNOON...WITH
LAYERED CLOUDS SPREAD OUT AHEAD OF THE FRONT OVER THE PACIFIC NW. AS
THE UPPER RIDGE OVER THE REGION SHIFTS E TONIGHT AND THU THE FLOW
WILL TURN MORE TO THE SW...WITH THE FRONT SLOWLY PUSHING INLAND.
MODEL SOUNDINGS AGREE IN SHOWING MOISTURE INITIALLY IN THEMID AND
HIGH LEVELS...ABOVE 700MB. BY LATE TONIGHT THOUGH MOISTURE BEGINS TO
SPREAD IN IN THE LOWER LEVELS. DYNAMICS WITH THIS FRONT HOWEVER ON
THE WEAK SIDE...SO WILL BE SLOW TO INCREASE POPS OVERNIGHT INLAND
AREAS...WHILE THE COAST AND COAST RANGE WILL BENEFIT FROM AN
INCREASING LOW LEVEL SSW FLOW. WITH CLOUDS LIMITING RADIATIONAL
COOLING TONIGHT AND MUCH OF THE AREA STILL IN THE WARM SECTOR...
SHOULD BE ANOTHER UNSEASONABLY MILD NIGHT. THU THE FRONT APPEARS TO
STALL OVER THE REGION AS THE LOW OFFSHORE DIGS IN A BIT MORE. WITH
BAROCLINIC ZONE STALLED AND LOW LEVEL FLOW A LITTLE MORE ONSHORE
WILL TAKE POPS BACK UP TO LIKELY TO CATEGORICAL FOR MOST OF THE
REGION. ALTHOUGH THERE IS ONLY MODEST COOLING TO AIR MASS WITH THE
FRONT...CLOUDS AND EXPECTED OCCASIONAL LIGHT RAIN WILL LIMIT HIGH
TEMPS TO THE 50S MOST LOW ELEVATION AREAS.

LATE THU NIGHT...AND ESP FRI BETTER MOISTURE ARRIVES AS A NORTHERN
STREAM SHORT WAVE DROPS DOWN THROUGH BC WITH A TRUE COLD FRONT
DROPPING DOWN THE COAST AHEAD OF IT. MOIST ISENTROPIC LIFT IN THE
LOWER LEVELS IMPROVES AHEAD OF THE COLD FRONT AS WELL...BEST
DEPICTED IN MODEL 290K ISENTROPIC FIELDS. AS SUCH...POTENTIAL FOR
RAIN PICKS UP CONSIDERABLY BY FRI.

MODELS IN RELATIVELY GOOD AGREEMENT IN DEPICTING THE WESTERN
CANADIAN TROUGH DIGGING DOWN INTO THE PACIFIC NW STATES FRI NIGHT
AND SAT. ALL MODELS AT THIS POINT SHOWING A VIGOROUS CONTINENTAL
TYPE COLD FRONT MOVING S THROUGH SW WA AND NW OREGON FRI NIGHT.
PATTERN IS REMINISCENT OF A COLD FRONT FROM BACK ON 19 NOVEMBER 2003
THAT BROUGHT LOW ELEVATION SNOW TO INTERIOR N PARTS OF THE FORECAST
AREA. KEYS TO DOING SOMETHING SIMILAR RELY ON SOME OF THE
PRECIPITATION FALLING OVER AND BEHIND THE FRONT AS WELL AS STRONG
FRONTOGENETIC FORCING TO ALLOW FOR DYNAMIC COOLING. MODEL SOUNDINGS
AT THIS POINT INDICATE SNOW LEVEL FALLING RAPIDLY BEHIND THE FRONT
FRI NIGHT SUGGESTING AT LEAST A MIX OF RAIN AND SNOW POSSIBLE DOWN
TO FAIRLY LOW LEVELS. WHETHER IT WOULD BE COLD ENOUGH TO MIX SNOW AT
LOWEST ELEVATIONS IS ANYBODYS GUESS AT THIS POINT...BUT GIVEN THE
AGREEMENT IN MODELS AT THIS POINT WILL CARRY A MENTION OF MIXED RAIN
AND SNOW POSSIBLE FOR THE N PART OF THE AREA FRI NIGHT. SAT SEES A
RATHER COLD AIR MASS SETTLING IN OVER THE REGION BEHIND THE FRONT...
WITH A LINGERING CHANCE FOR SHOWERS...POTENTIALLY MIXED WITH SNOW IN
THE N...AS THE UPPER TROUGH MOVES THROUGH.

.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY...MOST GUIDANCE
SUGGESTS THE UPPER TROUGH AXIS RESPONSIBLE FOR SATURDAYS MIXED
RAIN/SNOW SHOWERS WILL BE MOVING ACROSS THE CASCADES SAT NIGHT...
WITH ANY LINGERING SNOW SHOWERS COMING TO END OVERNIGHT. EXPECT SOME
CLEARING SAT NIGHT AS COLD HIGH PRESSURE BUILDS DOWN FROM BRITISH
COLUMBIA...WITH LOW TEMPS LIKELY GETTING WELL INTO THE 20S FOR MOST
SPOTS. WITH HIGH PRESSURE STRENGTHENING EAST OF THE CASCADES...
EXPECT STRONG EAST WINDS TO RAMP UP THROUGH THE GORGE SUNDAY MORNING
AND PERSIST FOR MUCH OF THE PERIOD THROUGH WEDNESDAY...WITH BREEZY
CONDITIONS SPILLING INTO THE PORTLAND/VANCOUVER METRO. MONDAY MAY BE
A BRIEF BREAK FROM THE WINDS AS A SYSTEM PASSES BY TO OUR NORTH.

MEANWHILE...A DISTURBANCE FROM THE ALEUTIANS IS EXPECTED TO CUT OFF
FROM THE MAIN PACIFIC JET AND SETTLE OFF THE CALIFORNIA COAST BY
SUNDAY...WHERE IT WILL LIKELY LINGER FOR A COUPLE DAYS. THERE IS A
CHANCE THIS SYSTEM COULD COME CLOSE ENOUGH TO SPREAD SOME PRECIP
NORTHWARD INTO OUR FORECAST AREA SUN NIGHT OR MON. THE 12Z GFS AND
CANADIAN MODELS ARE MORE AGGRESSIVE WITH THIS THAN THE ECMWF. IF
THIS OCCURS...THERE MAY BE SOME LIGHT FREEZING RAIN IN PORTIONS OF
THE WILLAMETTE VALLEY WITH SOME SNOW OR LIGHT FREEZING RAIN IN THE
GORGE. CUTOFF LOWS SUCH AS THIS ONE ARE NOTORIOUSLY DIFFICULT TO
FORECAST...AS MODELS STRUGGLE WITH THEM IN THE EXTENDED FORECAST
PERIOD. WHERE THIS UPPER LOW GOES WILL DICTATE THE WEATHER THROUGH
MIDWEEK...BUT TEMPS ARE EXPECTED TO SLOWLY MODERATE TUESDAY AND
WEDNESDAY.  WEAGLE
&&

.AVIATION...GENERALLY VFR ACROSS THE AREA EARLY THIS AFTERNOON
EXCEPT FOR AREAS OF IFR ALONG THE COAST FROM KAST TO KHQM. EXPECT
VFR TO PREVAIL THROUGH AT LEAST THE EVENING HOURS. CIGS LOWER
ALONG THE COAST AFTER 03Z THU AS A COLD FRONT APPROACHES. LOOK FOR
CONDITIONS ALONG THE COAST TO FALL INTO MVFR BETWEEN 04Z TO 06Z
WITH PRECIP INCREASING OVERNIGHT. VFR SHOULD HOLD OVER THE INLAND
AREAS THROUGH AT LEAST 12Z THU...THEN MVFR CONDITIONS
INCREASE...WITH HIGHER TERRAIN BECOMING OBSCURED. CONSIDERABLE
LOW-LEVEL MOISTURE RESIDES OVER THE AREA THU WHICH WILL LEAD TO
WIDESPREAD MVFR OR WORSE CONDITIONS.

KPDX AND APPROACHES...VFR CONDITIONS TO PREVAIL THROUGH AT LEAST
12Z THU. RAIN DEVELOPS OVER WRN APPROACHES AROUND 10Z THEN SPREADS
E THEREAFTER...WITH LOCALIZED MVFR DEVELOPING AFTER 13Z.
INCREASING MVFR OR WORSE CONDITIONS THU MORNING THROUGH THE
AFTERNOON. WEISHAAR

&&

.MARINE...WIND SPEEDS EARLY THIS AFTERNOON STILL AT 15 TO 20 KT
WITH GUSTS UP TO 25 KT. EXPECT SPEEDS TO RAMP UP LATER THIS
AFTERNOON AHEAD OF AN APPROACHING FRONTAL SYSTEM. SHOULD SEE GALE
FORCE WIND GUSTS OVER MUCH OF THE WATERS BY LATE THIS AFTERNOON...
BUT MORE SO THIS EVENING AND OVERNIGHT. ALTHOUGH NOT A CLASSIC
CASE...SOME MODEL GUIDANCE IS SUGGESTING THE POTENTIAL FOR MINOR
COASTAL JET ENHANCEMENT WITHIN 20 NM. COULD SEE SOME GUSTS UP TO
40 KT IF THIS OCCURS. HIGH-END SMALL CRAFT ADVISORY SPEEDS PERSIST
THU MORNING. LATEST MODEL RUNS SHOW 20-25 KT NW-N WIND DEVELOPING
OVER THE N WATERS FRI EVENING THEN SPREADING FURTHER S OVERNIGHT
AS A STRONG COLD FRONT DROPS SOUTH OUT OF CANADA. THE WIND TURNS
OFFSHORE SAT WITH POTENTIAL GUSTS 20 TO 30 KT NEAR GAPS IN THE
COASTAL TERRAIN. WIND SPEEDS RELAX SUN.

SEAS EXPECTED TO BUILD TO 10 FT THIS EVENING THEN REMAIN AT OR
ABOVE 10 FT THROUGH AT LEAST SAT MORNING. WAVE HEIGHTS DROP OFF
SAT AFTERNOON AS OFFSHOR FLOW DEVELOPS. WEISHAAR

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 PM PST THIS AFTERNOON FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     GALE WARNING FROM 4 PM THIS AFTERNOON TO 4 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 4 PM THIS
     AFTERNOON TO 4 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 262159
AFDPQR

FXUS66 KPQR DDHHMM
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
200 PM PST WED NOV 26 2014

.SYNOPSIS...A WEAK COLD FRONT OFF THE COAST WED AFTERNOON WILL PUSH
SLOWLY INLAND TONIGHT AND THU. THE FRONT WILL STALL OVER WESTERN
OREGON THU NIGHT AND FRI...THEN ANOTHER STRONGER COLD FRONT WILL
MOVE S THROUGH THE REGION FRI NIGHT USHERING COLDER WEATHER FOR THE
WEEKEND. HIGH PRES OVER THE INTERIOR NW WILL TURN THE FLOW OFFSHORE
BY SUN FOR DRY BUT COLD WEATHER. SUN NIGHT AND MON A SYSTEM COMING
UP FROM THE S WILL ATTEMPT TO SPREAD SOME PRECIPITATION UP OVER THE
COLD AIR MASS LEFT OVER FROM THE WEEKEND.
&&

.SHORT TERM...A WEAK COLD FRONT WAS OFFSHORE WED AFTERNOON...WITH
LAYERED CLOUDS SPREAD OUT AHEAD OF THE FRONT OVER THE PACIFIC NW. AS
THE UPPER RIDGE OVER THE REGION SHIFTS E TONIGHT AND THU THE FLOW
WILL TURN MORE TO THE SW...WITH THE FRONT SLOWLY PUSHING INLAND.
MODEL SOUNDINGS AGREE IN SHOWING MOISTURE INITIALLY IN THEMID AND
HIGH LEVELS...ABOVE 700MB. BY LATE TONIGHT THOUGH MOISTURE BEGINS TO
SPREAD IN IN THE LOWER LEVELS. DYNAMICS WITH THIS FRONT HOWEVER ON
THE WEAK SIDE...SO WILL BE SLOW TO INCREASE POPS OVERNIGHT INLAND
AREAS...WHILE THE COAST AND COAST RANGE WILL BENEFIT FROM AN
INCREASING LOW LEVEL SSW FLOW. WITH CLOUDS LIMITING RADIATIONAL
COOLING TONIGHT AND MUCH OF THE AREA STILL IN THE WARM SECTOR...
SHOULD BE ANOTHER UNSEASONABLY MILD NIGHT. THU THE FRONT APPEARS TO
STALL OVER THE REGION AS THE LOW OFFSHORE DIGS IN A BIT MORE. WITH
BAROCLINIC ZONE STALLED AND LOW LEVEL FLOW A LITTLE MORE ONSHORE
WILL TAKE POPS BACK UP TO LIKELY TO CATEGORICAL FOR MOST OF THE
REGION. ALTHOUGH THERE IS ONLY MODEST COOLING TO AIR MASS WITH THE
FRONT...CLOUDS AND EXPECTED OCCASIONAL LIGHT RAIN WILL LIMIT HIGH
TEMPS TO THE 50S MOST LOW ELEVATION AREAS.

LATE THU NIGHT...AND ESP FRI BETTER MOISTURE ARRIVES AS A NORTHERN
STREAM SHORT WAVE DROPS DOWN THROUGH BC WITH A TRUE COLD FRONT
DROPPING DOWN THE COAST AHEAD OF IT. MOIST ISENTROPIC LIFT IN THE
LOWER LEVELS IMPROVES AHEAD OF THE COLD FRONT AS WELL...BEST
DEPICTED IN MODEL 290K ISENTROPIC FIELDS. AS SUCH...POTENTIAL FOR
RAIN PICKS UP CONSIDERABLY BY FRI.

MODELS IN RELATIVELY GOOD AGREEMENT IN DEPICTING THE WESTERN
CANADIAN TROUGH DIGGING DOWN INTO THE PACIFIC NW STATES FRI NIGHT
AND SAT. ALL MODELS AT THIS POINT SHOWING A VIGOROUS CONTINENTAL
TYPE COLD FRONT MOVING S THROUGH SW WA AND NW OREGON FRI NIGHT.
PATTERN IS REMINISCENT OF A COLD FRONT FROM BACK ON 19 NOVEMBER 2003
THAT BROUGHT LOW ELEVATION SNOW TO INTERIOR N PARTS OF THE FORECAST
AREA. KEYS TO DOING SOMETHING SIMILAR RELY ON SOME OF THE
PRECIPITATION FALLING OVER AND BEHIND THE FRONT AS WELL AS STRONG
FRONTOGENETIC FORCING TO ALLOW FOR DYNAMIC COOLING. MODEL SOUNDINGS
AT THIS POINT INDICATE SNOW LEVEL FALLING RAPIDLY BEHIND THE FRONT
FRI NIGHT SUGGESTING AT LEAST A MIX OF RAIN AND SNOW POSSIBLE DOWN
TO FAIRLY LOW LEVELS. WHETHER IT WOULD BE COLD ENOUGH TO MIX SNOW AT
LOWEST ELEVATIONS IS ANYBODYS GUESS AT THIS POINT...BUT GIVEN THE
AGREEMENT IN MODELS AT THIS POINT WILL CARRY A MENTION OF MIXED RAIN
AND SNOW POSSIBLE FOR THE N PART OF THE AREA FRI NIGHT. SAT SEES A
RATHER COLD AIR MASS SETTLING IN OVER THE REGION BEHIND THE FRONT...
WITH A LINGERING CHANCE FOR SHOWERS...POTENTIALLY MIXED WITH SNOW IN
THE N...AS THE UPPER TROUGH MOVES THROUGH.

.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY...MOST GUIDANCE
SUGGESTS THE UPPER TROUGH AXIS RESPONSIBLE FOR SATURDAYS MIXED
RAIN/SNOW SHOWERS WILL BE MOVING ACROSS THE CASCADES SAT NIGHT...
WITH ANY LINGERING SNOW SHOWERS COMING TO END OVERNIGHT. EXPECT SOME
CLEARING SAT NIGHT AS COLD HIGH PRESSURE BUILDS DOWN FROM BRITISH
COLUMBIA...WITH LOW TEMPS LIKELY GETTING WELL INTO THE 20S FOR MOST
SPOTS. WITH HIGH PRESSURE STRENGTHENING EAST OF THE CASCADES...
EXPECT STRONG EAST WINDS TO RAMP UP THROUGH THE GORGE SUNDAY MORNING
AND PERSIST FOR MUCH OF THE PERIOD THROUGH WEDNESDAY...WITH BREEZY
CONDITIONS SPILLING INTO THE PORTLAND/VANCOUVER METRO. MONDAY MAY BE
A BRIEF BREAK FROM THE WINDS AS A SYSTEM PASSES BY TO OUR NORTH.

MEANWHILE...A DISTURBANCE FROM THE ALEUTIANS IS EXPECTED TO CUT OFF
FROM THE MAIN PACIFIC JET AND SETTLE OFF THE CALIFORNIA COAST BY
SUNDAY...WHERE IT WILL LIKELY LINGER FOR A COUPLE DAYS. THERE IS A
CHANCE THIS SYSTEM COULD COME CLOSE ENOUGH TO SPREAD SOME PRECIP
NORTHWARD INTO OUR FORECAST AREA SUN NIGHT OR MON. THE 12Z GFS AND
CANADIAN MODELS ARE MORE AGGRESSIVE WITH THIS THAN THE ECMWF. IF
THIS OCCURS...THERE MAY BE SOME LIGHT FREEZING RAIN IN PORTIONS OF
THE WILLAMETTE VALLEY WITH SOME SNOW OR LIGHT FREEZING RAIN IN THE
GORGE. CUTOFF LOWS SUCH AS THIS ONE ARE NOTORIOUSLY DIFFICULT TO
FORECAST...AS MODELS STRUGGLE WITH THEM IN THE EXTENDED FORECAST
PERIOD. WHERE THIS UPPER LOW GOES WILL DICTATE THE WEATHER THROUGH
MIDWEEK...BUT TEMPS ARE EXPECTED TO SLOWLY MODERATE TUESDAY AND
WEDNESDAY.  WEAGLE
&&

.AVIATION...GENERALLY VFR ACROSS THE AREA EARLY THIS AFTERNOON
EXCEPT FOR AREAS OF IFR ALONG THE COAST FROM KAST TO KHQM. EXPECT
VFR TO PREVAIL THROUGH AT LEAST THE EVENING HOURS. CIGS LOWER
ALONG THE COAST AFTER 03Z THU AS A COLD FRONT APPROACHES. LOOK FOR
CONDITIONS ALONG THE COAST TO FALL INTO MVFR BETWEEN 04Z TO 06Z
WITH PRECIP INCREASING OVERNIGHT. VFR SHOULD HOLD OVER THE INLAND
AREAS THROUGH AT LEAST 12Z THU...THEN MVFR CONDITIONS
INCREASE...WITH HIGHER TERRAIN BECOMING OBSCURED. CONSIDERABLE
LOW-LEVEL MOISTURE RESIDES OVER THE AREA THU WHICH WILL LEAD TO
WIDESPREAD MVFR OR WORSE CONDITIONS.

KPDX AND APPROACHES...VFR CONDITIONS TO PREVAIL THROUGH AT LEAST
12Z THU. RAIN DEVELOPS OVER WRN APPROACHES AROUND 10Z THEN SPREADS
E THEREAFTER...WITH LOCALIZED MVFR DEVELOPING AFTER 13Z.
INCREASING MVFR OR WORSE CONDITIONS THU MORNING THROUGH THE
AFTERNOON. WEISHAAR

&&

.MARINE...WIND SPEEDS EARLY THIS AFTERNOON STILL AT 15 TO 20 KT
WITH GUSTS UP TO 25 KT. EXPECT SPEEDS TO RAMP UP LATER THIS
AFTERNOON AHEAD OF AN APPROACHING FRONTAL SYSTEM. SHOULD SEE GALE
FORCE WIND GUSTS OVER MUCH OF THE WATERS BY LATE THIS AFTERNOON...
BUT MORE SO THIS EVENING AND OVERNIGHT. ALTHOUGH NOT A CLASSIC
CASE...SOME MODEL GUIDANCE IS SUGGESTING THE POTENTIAL FOR MINOR
COASTAL JET ENHANCEMENT WITHIN 20 NM. COULD SEE SOME GUSTS UP TO
40 KT IF THIS OCCURS. HIGH-END SMALL CRAFT ADVISORY SPEEDS PERSIST
THU MORNING. LATEST MODEL RUNS SHOW 20-25 KT NW-N WIND DEVELOPING
OVER THE N WATERS FRI EVENING THEN SPREADING FURTHER S OVERNIGHT
AS A STRONG COLD FRONT DROPS SOUTH OUT OF CANADA. THE WIND TURNS
OFFSHORE SAT WITH POTENTIAL GUSTS 20 TO 30 KT NEAR GAPS IN THE
COASTAL TERRAIN. WIND SPEEDS RELAX SUN.

SEAS EXPECTED TO BUILD TO 10 FT THIS EVENING THEN REMAIN AT OR
ABOVE 10 FT THROUGH AT LEAST SAT MORNING. WAVE HEIGHTS DROP OFF
SAT AFTERNOON AS OFFSHOR FLOW DEVELOPS. WEISHAAR

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 PM PST THIS AFTERNOON FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     GALE WARNING FROM 4 PM THIS AFTERNOON TO 4 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 4 PM THIS
     AFTERNOON TO 4 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 262159
AFDPQR

FXUS66 KPQR DDHHMM
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
200 PM PST WED NOV 26 2014

.SYNOPSIS...A WEAK COLD FRONT OFF THE COAST WED AFTERNOON WILL PUSH
SLOWLY INLAND TONIGHT AND THU. THE FRONT WILL STALL OVER WESTERN
OREGON THU NIGHT AND FRI...THEN ANOTHER STRONGER COLD FRONT WILL
MOVE S THROUGH THE REGION FRI NIGHT USHERING COLDER WEATHER FOR THE
WEEKEND. HIGH PRES OVER THE INTERIOR NW WILL TURN THE FLOW OFFSHORE
BY SUN FOR DRY BUT COLD WEATHER. SUN NIGHT AND MON A SYSTEM COMING
UP FROM THE S WILL ATTEMPT TO SPREAD SOME PRECIPITATION UP OVER THE
COLD AIR MASS LEFT OVER FROM THE WEEKEND.
&&

.SHORT TERM...A WEAK COLD FRONT WAS OFFSHORE WED AFTERNOON...WITH
LAYERED CLOUDS SPREAD OUT AHEAD OF THE FRONT OVER THE PACIFIC NW. AS
THE UPPER RIDGE OVER THE REGION SHIFTS E TONIGHT AND THU THE FLOW
WILL TURN MORE TO THE SW...WITH THE FRONT SLOWLY PUSHING INLAND.
MODEL SOUNDINGS AGREE IN SHOWING MOISTURE INITIALLY IN THEMID AND
HIGH LEVELS...ABOVE 700MB. BY LATE TONIGHT THOUGH MOISTURE BEGINS TO
SPREAD IN IN THE LOWER LEVELS. DYNAMICS WITH THIS FRONT HOWEVER ON
THE WEAK SIDE...SO WILL BE SLOW TO INCREASE POPS OVERNIGHT INLAND
AREAS...WHILE THE COAST AND COAST RANGE WILL BENEFIT FROM AN
INCREASING LOW LEVEL SSW FLOW. WITH CLOUDS LIMITING RADIATIONAL
COOLING TONIGHT AND MUCH OF THE AREA STILL IN THE WARM SECTOR...
SHOULD BE ANOTHER UNSEASONABLY MILD NIGHT. THU THE FRONT APPEARS TO
STALL OVER THE REGION AS THE LOW OFFSHORE DIGS IN A BIT MORE. WITH
BAROCLINIC ZONE STALLED AND LOW LEVEL FLOW A LITTLE MORE ONSHORE
WILL TAKE POPS BACK UP TO LIKELY TO CATEGORICAL FOR MOST OF THE
REGION. ALTHOUGH THERE IS ONLY MODEST COOLING TO AIR MASS WITH THE
FRONT...CLOUDS AND EXPECTED OCCASIONAL LIGHT RAIN WILL LIMIT HIGH
TEMPS TO THE 50S MOST LOW ELEVATION AREAS.

LATE THU NIGHT...AND ESP FRI BETTER MOISTURE ARRIVES AS A NORTHERN
STREAM SHORT WAVE DROPS DOWN THROUGH BC WITH A TRUE COLD FRONT
DROPPING DOWN THE COAST AHEAD OF IT. MOIST ISENTROPIC LIFT IN THE
LOWER LEVELS IMPROVES AHEAD OF THE COLD FRONT AS WELL...BEST
DEPICTED IN MODEL 290K ISENTROPIC FIELDS. AS SUCH...POTENTIAL FOR
RAIN PICKS UP CONSIDERABLY BY FRI.

MODELS IN RELATIVELY GOOD AGREEMENT IN DEPICTING THE WESTERN
CANADIAN TROUGH DIGGING DOWN INTO THE PACIFIC NW STATES FRI NIGHT
AND SAT. ALL MODELS AT THIS POINT SHOWING A VIGOROUS CONTINENTAL
TYPE COLD FRONT MOVING S THROUGH SW WA AND NW OREGON FRI NIGHT.
PATTERN IS REMINISCENT OF A COLD FRONT FROM BACK ON 19 NOVEMBER 2003
THAT BROUGHT LOW ELEVATION SNOW TO INTERIOR N PARTS OF THE FORECAST
AREA. KEYS TO DOING SOMETHING SIMILAR RELY ON SOME OF THE
PRECIPITATION FALLING OVER AND BEHIND THE FRONT AS WELL AS STRONG
FRONTOGENETIC FORCING TO ALLOW FOR DYNAMIC COOLING. MODEL SOUNDINGS
AT THIS POINT INDICATE SNOW LEVEL FALLING RAPIDLY BEHIND THE FRONT
FRI NIGHT SUGGESTING AT LEAST A MIX OF RAIN AND SNOW POSSIBLE DOWN
TO FAIRLY LOW LEVELS. WHETHER IT WOULD BE COLD ENOUGH TO MIX SNOW AT
LOWEST ELEVATIONS IS ANYBODYS GUESS AT THIS POINT...BUT GIVEN THE
AGREEMENT IN MODELS AT THIS POINT WILL CARRY A MENTION OF MIXED RAIN
AND SNOW POSSIBLE FOR THE N PART OF THE AREA FRI NIGHT. SAT SEES A
RATHER COLD AIR MASS SETTLING IN OVER THE REGION BEHIND THE FRONT...
WITH A LINGERING CHANCE FOR SHOWERS...POTENTIALLY MIXED WITH SNOW IN
THE N...AS THE UPPER TROUGH MOVES THROUGH.

.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY...MOST GUIDANCE
SUGGESTS THE UPPER TROUGH AXIS RESPONSIBLE FOR SATURDAYS MIXED
RAIN/SNOW SHOWERS WILL BE MOVING ACROSS THE CASCADES SAT NIGHT...
WITH ANY LINGERING SNOW SHOWERS COMING TO END OVERNIGHT. EXPECT SOME
CLEARING SAT NIGHT AS COLD HIGH PRESSURE BUILDS DOWN FROM BRITISH
COLUMBIA...WITH LOW TEMPS LIKELY GETTING WELL INTO THE 20S FOR MOST
SPOTS. WITH HIGH PRESSURE STRENGTHENING EAST OF THE CASCADES...
EXPECT STRONG EAST WINDS TO RAMP UP THROUGH THE GORGE SUNDAY MORNING
AND PERSIST FOR MUCH OF THE PERIOD THROUGH WEDNESDAY...WITH BREEZY
CONDITIONS SPILLING INTO THE PORTLAND/VANCOUVER METRO. MONDAY MAY BE
A BRIEF BREAK FROM THE WINDS AS A SYSTEM PASSES BY TO OUR NORTH.

MEANWHILE...A DISTURBANCE FROM THE ALEUTIANS IS EXPECTED TO CUT OFF
FROM THE MAIN PACIFIC JET AND SETTLE OFF THE CALIFORNIA COAST BY
SUNDAY...WHERE IT WILL LIKELY LINGER FOR A COUPLE DAYS. THERE IS A
CHANCE THIS SYSTEM COULD COME CLOSE ENOUGH TO SPREAD SOME PRECIP
NORTHWARD INTO OUR FORECAST AREA SUN NIGHT OR MON. THE 12Z GFS AND
CANADIAN MODELS ARE MORE AGGRESSIVE WITH THIS THAN THE ECMWF. IF
THIS OCCURS...THERE MAY BE SOME LIGHT FREEZING RAIN IN PORTIONS OF
THE WILLAMETTE VALLEY WITH SOME SNOW OR LIGHT FREEZING RAIN IN THE
GORGE. CUTOFF LOWS SUCH AS THIS ONE ARE NOTORIOUSLY DIFFICULT TO
FORECAST...AS MODELS STRUGGLE WITH THEM IN THE EXTENDED FORECAST
PERIOD. WHERE THIS UPPER LOW GOES WILL DICTATE THE WEATHER THROUGH
MIDWEEK...BUT TEMPS ARE EXPECTED TO SLOWLY MODERATE TUESDAY AND
WEDNESDAY.  WEAGLE
&&

.AVIATION...GENERALLY VFR ACROSS THE AREA EARLY THIS AFTERNOON
EXCEPT FOR AREAS OF IFR ALONG THE COAST FROM KAST TO KHQM. EXPECT
VFR TO PREVAIL THROUGH AT LEAST THE EVENING HOURS. CIGS LOWER
ALONG THE COAST AFTER 03Z THU AS A COLD FRONT APPROACHES. LOOK FOR
CONDITIONS ALONG THE COAST TO FALL INTO MVFR BETWEEN 04Z TO 06Z
WITH PRECIP INCREASING OVERNIGHT. VFR SHOULD HOLD OVER THE INLAND
AREAS THROUGH AT LEAST 12Z THU...THEN MVFR CONDITIONS
INCREASE...WITH HIGHER TERRAIN BECOMING OBSCURED. CONSIDERABLE
LOW-LEVEL MOISTURE RESIDES OVER THE AREA THU WHICH WILL LEAD TO
WIDESPREAD MVFR OR WORSE CONDITIONS.

KPDX AND APPROACHES...VFR CONDITIONS TO PREVAIL THROUGH AT LEAST
12Z THU. RAIN DEVELOPS OVER WRN APPROACHES AROUND 10Z THEN SPREADS
E THEREAFTER...WITH LOCALIZED MVFR DEVELOPING AFTER 13Z.
INCREASING MVFR OR WORSE CONDITIONS THU MORNING THROUGH THE
AFTERNOON. WEISHAAR

&&

.MARINE...WIND SPEEDS EARLY THIS AFTERNOON STILL AT 15 TO 20 KT
WITH GUSTS UP TO 25 KT. EXPECT SPEEDS TO RAMP UP LATER THIS
AFTERNOON AHEAD OF AN APPROACHING FRONTAL SYSTEM. SHOULD SEE GALE
FORCE WIND GUSTS OVER MUCH OF THE WATERS BY LATE THIS AFTERNOON...
BUT MORE SO THIS EVENING AND OVERNIGHT. ALTHOUGH NOT A CLASSIC
CASE...SOME MODEL GUIDANCE IS SUGGESTING THE POTENTIAL FOR MINOR
COASTAL JET ENHANCEMENT WITHIN 20 NM. COULD SEE SOME GUSTS UP TO
40 KT IF THIS OCCURS. HIGH-END SMALL CRAFT ADVISORY SPEEDS PERSIST
THU MORNING. LATEST MODEL RUNS SHOW 20-25 KT NW-N WIND DEVELOPING
OVER THE N WATERS FRI EVENING THEN SPREADING FURTHER S OVERNIGHT
AS A STRONG COLD FRONT DROPS SOUTH OUT OF CANADA. THE WIND TURNS
OFFSHORE SAT WITH POTENTIAL GUSTS 20 TO 30 KT NEAR GAPS IN THE
COASTAL TERRAIN. WIND SPEEDS RELAX SUN.

SEAS EXPECTED TO BUILD TO 10 FT THIS EVENING THEN REMAIN AT OR
ABOVE 10 FT THROUGH AT LEAST SAT MORNING. WAVE HEIGHTS DROP OFF
SAT AFTERNOON AS OFFSHOR FLOW DEVELOPS. WEISHAAR

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 PM PST THIS AFTERNOON FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     GALE WARNING FROM 4 PM THIS AFTERNOON TO 4 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 4 PM THIS
     AFTERNOON TO 4 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 262159
AFDPQR

FXUS66 KPQR DDHHMM
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
200 PM PST WED NOV 26 2014

.SYNOPSIS...A WEAK COLD FRONT OFF THE COAST WED AFTERNOON WILL PUSH
SLOWLY INLAND TONIGHT AND THU. THE FRONT WILL STALL OVER WESTERN
OREGON THU NIGHT AND FRI...THEN ANOTHER STRONGER COLD FRONT WILL
MOVE S THROUGH THE REGION FRI NIGHT USHERING COLDER WEATHER FOR THE
WEEKEND. HIGH PRES OVER THE INTERIOR NW WILL TURN THE FLOW OFFSHORE
BY SUN FOR DRY BUT COLD WEATHER. SUN NIGHT AND MON A SYSTEM COMING
UP FROM THE S WILL ATTEMPT TO SPREAD SOME PRECIPITATION UP OVER THE
COLD AIR MASS LEFT OVER FROM THE WEEKEND.
&&

.SHORT TERM...A WEAK COLD FRONT WAS OFFSHORE WED AFTERNOON...WITH
LAYERED CLOUDS SPREAD OUT AHEAD OF THE FRONT OVER THE PACIFIC NW. AS
THE UPPER RIDGE OVER THE REGION SHIFTS E TONIGHT AND THU THE FLOW
WILL TURN MORE TO THE SW...WITH THE FRONT SLOWLY PUSHING INLAND.
MODEL SOUNDINGS AGREE IN SHOWING MOISTURE INITIALLY IN THEMID AND
HIGH LEVELS...ABOVE 700MB. BY LATE TONIGHT THOUGH MOISTURE BEGINS TO
SPREAD IN IN THE LOWER LEVELS. DYNAMICS WITH THIS FRONT HOWEVER ON
THE WEAK SIDE...SO WILL BE SLOW TO INCREASE POPS OVERNIGHT INLAND
AREAS...WHILE THE COAST AND COAST RANGE WILL BENEFIT FROM AN
INCREASING LOW LEVEL SSW FLOW. WITH CLOUDS LIMITING RADIATIONAL
COOLING TONIGHT AND MUCH OF THE AREA STILL IN THE WARM SECTOR...
SHOULD BE ANOTHER UNSEASONABLY MILD NIGHT. THU THE FRONT APPEARS TO
STALL OVER THE REGION AS THE LOW OFFSHORE DIGS IN A BIT MORE. WITH
BAROCLINIC ZONE STALLED AND LOW LEVEL FLOW A LITTLE MORE ONSHORE
WILL TAKE POPS BACK UP TO LIKELY TO CATEGORICAL FOR MOST OF THE
REGION. ALTHOUGH THERE IS ONLY MODEST COOLING TO AIR MASS WITH THE
FRONT...CLOUDS AND EXPECTED OCCASIONAL LIGHT RAIN WILL LIMIT HIGH
TEMPS TO THE 50S MOST LOW ELEVATION AREAS.

LATE THU NIGHT...AND ESP FRI BETTER MOISTURE ARRIVES AS A NORTHERN
STREAM SHORT WAVE DROPS DOWN THROUGH BC WITH A TRUE COLD FRONT
DROPPING DOWN THE COAST AHEAD OF IT. MOIST ISENTROPIC LIFT IN THE
LOWER LEVELS IMPROVES AHEAD OF THE COLD FRONT AS WELL...BEST
DEPICTED IN MODEL 290K ISENTROPIC FIELDS. AS SUCH...POTENTIAL FOR
RAIN PICKS UP CONSIDERABLY BY FRI.

MODELS IN RELATIVELY GOOD AGREEMENT IN DEPICTING THE WESTERN
CANADIAN TROUGH DIGGING DOWN INTO THE PACIFIC NW STATES FRI NIGHT
AND SAT. ALL MODELS AT THIS POINT SHOWING A VIGOROUS CONTINENTAL
TYPE COLD FRONT MOVING S THROUGH SW WA AND NW OREGON FRI NIGHT.
PATTERN IS REMINISCENT OF A COLD FRONT FROM BACK ON 19 NOVEMBER 2003
THAT BROUGHT LOW ELEVATION SNOW TO INTERIOR N PARTS OF THE FORECAST
AREA. KEYS TO DOING SOMETHING SIMILAR RELY ON SOME OF THE
PRECIPITATION FALLING OVER AND BEHIND THE FRONT AS WELL AS STRONG
FRONTOGENETIC FORCING TO ALLOW FOR DYNAMIC COOLING. MODEL SOUNDINGS
AT THIS POINT INDICATE SNOW LEVEL FALLING RAPIDLY BEHIND THE FRONT
FRI NIGHT SUGGESTING AT LEAST A MIX OF RAIN AND SNOW POSSIBLE DOWN
TO FAIRLY LOW LEVELS. WHETHER IT WOULD BE COLD ENOUGH TO MIX SNOW AT
LOWEST ELEVATIONS IS ANYBODYS GUESS AT THIS POINT...BUT GIVEN THE
AGREEMENT IN MODELS AT THIS POINT WILL CARRY A MENTION OF MIXED RAIN
AND SNOW POSSIBLE FOR THE N PART OF THE AREA FRI NIGHT. SAT SEES A
RATHER COLD AIR MASS SETTLING IN OVER THE REGION BEHIND THE FRONT...
WITH A LINGERING CHANCE FOR SHOWERS...POTENTIALLY MIXED WITH SNOW IN
THE N...AS THE UPPER TROUGH MOVES THROUGH.

.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY...MOST GUIDANCE
SUGGESTS THE UPPER TROUGH AXIS RESPONSIBLE FOR SATURDAYS MIXED
RAIN/SNOW SHOWERS WILL BE MOVING ACROSS THE CASCADES SAT NIGHT...
WITH ANY LINGERING SNOW SHOWERS COMING TO END OVERNIGHT. EXPECT SOME
CLEARING SAT NIGHT AS COLD HIGH PRESSURE BUILDS DOWN FROM BRITISH
COLUMBIA...WITH LOW TEMPS LIKELY GETTING WELL INTO THE 20S FOR MOST
SPOTS. WITH HIGH PRESSURE STRENGTHENING EAST OF THE CASCADES...
EXPECT STRONG EAST WINDS TO RAMP UP THROUGH THE GORGE SUNDAY MORNING
AND PERSIST FOR MUCH OF THE PERIOD THROUGH WEDNESDAY...WITH BREEZY
CONDITIONS SPILLING INTO THE PORTLAND/VANCOUVER METRO. MONDAY MAY BE
A BRIEF BREAK FROM THE WINDS AS A SYSTEM PASSES BY TO OUR NORTH.

MEANWHILE...A DISTURBANCE FROM THE ALEUTIANS IS EXPECTED TO CUT OFF
FROM THE MAIN PACIFIC JET AND SETTLE OFF THE CALIFORNIA COAST BY
SUNDAY...WHERE IT WILL LIKELY LINGER FOR A COUPLE DAYS. THERE IS A
CHANCE THIS SYSTEM COULD COME CLOSE ENOUGH TO SPREAD SOME PRECIP
NORTHWARD INTO OUR FORECAST AREA SUN NIGHT OR MON. THE 12Z GFS AND
CANADIAN MODELS ARE MORE AGGRESSIVE WITH THIS THAN THE ECMWF. IF
THIS OCCURS...THERE MAY BE SOME LIGHT FREEZING RAIN IN PORTIONS OF
THE WILLAMETTE VALLEY WITH SOME SNOW OR LIGHT FREEZING RAIN IN THE
GORGE. CUTOFF LOWS SUCH AS THIS ONE ARE NOTORIOUSLY DIFFICULT TO
FORECAST...AS MODELS STRUGGLE WITH THEM IN THE EXTENDED FORECAST
PERIOD. WHERE THIS UPPER LOW GOES WILL DICTATE THE WEATHER THROUGH
MIDWEEK...BUT TEMPS ARE EXPECTED TO SLOWLY MODERATE TUESDAY AND
WEDNESDAY.  WEAGLE
&&

.AVIATION...GENERALLY VFR ACROSS THE AREA EARLY THIS AFTERNOON
EXCEPT FOR AREAS OF IFR ALONG THE COAST FROM KAST TO KHQM. EXPECT
VFR TO PREVAIL THROUGH AT LEAST THE EVENING HOURS. CIGS LOWER
ALONG THE COAST AFTER 03Z THU AS A COLD FRONT APPROACHES. LOOK FOR
CONDITIONS ALONG THE COAST TO FALL INTO MVFR BETWEEN 04Z TO 06Z
WITH PRECIP INCREASING OVERNIGHT. VFR SHOULD HOLD OVER THE INLAND
AREAS THROUGH AT LEAST 12Z THU...THEN MVFR CONDITIONS
INCREASE...WITH HIGHER TERRAIN BECOMING OBSCURED. CONSIDERABLE
LOW-LEVEL MOISTURE RESIDES OVER THE AREA THU WHICH WILL LEAD TO
WIDESPREAD MVFR OR WORSE CONDITIONS.

KPDX AND APPROACHES...VFR CONDITIONS TO PREVAIL THROUGH AT LEAST
12Z THU. RAIN DEVELOPS OVER WRN APPROACHES AROUND 10Z THEN SPREADS
E THEREAFTER...WITH LOCALIZED MVFR DEVELOPING AFTER 13Z.
INCREASING MVFR OR WORSE CONDITIONS THU MORNING THROUGH THE
AFTERNOON. WEISHAAR

&&

.MARINE...WIND SPEEDS EARLY THIS AFTERNOON STILL AT 15 TO 20 KT
WITH GUSTS UP TO 25 KT. EXPECT SPEEDS TO RAMP UP LATER THIS
AFTERNOON AHEAD OF AN APPROACHING FRONTAL SYSTEM. SHOULD SEE GALE
FORCE WIND GUSTS OVER MUCH OF THE WATERS BY LATE THIS AFTERNOON...
BUT MORE SO THIS EVENING AND OVERNIGHT. ALTHOUGH NOT A CLASSIC
CASE...SOME MODEL GUIDANCE IS SUGGESTING THE POTENTIAL FOR MINOR
COASTAL JET ENHANCEMENT WITHIN 20 NM. COULD SEE SOME GUSTS UP TO
40 KT IF THIS OCCURS. HIGH-END SMALL CRAFT ADVISORY SPEEDS PERSIST
THU MORNING. LATEST MODEL RUNS SHOW 20-25 KT NW-N WIND DEVELOPING
OVER THE N WATERS FRI EVENING THEN SPREADING FURTHER S OVERNIGHT
AS A STRONG COLD FRONT DROPS SOUTH OUT OF CANADA. THE WIND TURNS
OFFSHORE SAT WITH POTENTIAL GUSTS 20 TO 30 KT NEAR GAPS IN THE
COASTAL TERRAIN. WIND SPEEDS RELAX SUN.

SEAS EXPECTED TO BUILD TO 10 FT THIS EVENING THEN REMAIN AT OR
ABOVE 10 FT THROUGH AT LEAST SAT MORNING. WAVE HEIGHTS DROP OFF
SAT AFTERNOON AS OFFSHOR FLOW DEVELOPS. WEISHAAR

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 PM PST THIS AFTERNOON FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     GALE WARNING FROM 4 PM THIS AFTERNOON TO 4 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 4 PM THIS
     AFTERNOON TO 4 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 261952
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
1152 AM PST WED NOV 26 2014

.SYNOPSIS...
Mild and breezy weather is expected today and Thanksgiving. By
late this morning, snow levels should rise above the mountain
passes. Motorists with plans to travel over the mountain passes
should experience good conditions this afternoon through Friday
afternoon. The arrival of a cold front Friday night into Saturday
will bring winter driving conditions to the mountain passes and
much cooler weather for the weekend.



&&

.DISCUSSION...
We have issued a dense fog advisory to cover hazardous travel
along the Highway 2 corridor between Airway Heights to Wilbur and
onto the Waterville Plateau. With warmer air moving in aloft, the
inversions are strengthening and cloud decks are lowering with
visibilities down near 1/8 mile in spots. Fog looks to be clearing
down near Ritzville so hazard will mainly address travel along Highway
2. /sb

&&

.AVIATION...
18Z TAFS: Recent rain/snow and warming aloft will promote areas
of fog and low clouds across most terminals this morning with
improving conditions expected through this evening. Areas of
LIFR/IFR fog currently stretches across the Upper Columbia Basin
from KCOE to KMWH. Confidence is low regarding exact timing for
improvements but gusty S/SW winds in the lower Basin should
promote improving conditions KPUW-KLWS by 20Z then expanding N
through 06z. KMWH/KEAT will carry the lower probabilities for
clearing. The upper-level ridge will flatten tomorrow suppressing
the moist frontal boundary back south lowering cigs btwn 4-6K ft
agl and incr the threat for light rain.  /sb




&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        46  42  50  41  46  27 /  20  30  30  20  70  60
Coeur d`Alene  45  41  48  41  45  29 /  40  30  30  40  80  70
Pullman        53  44  53  43  49  32 /  10  30  30  30  90  90
Lewiston       57  47  58  46  53  38 /  10  10  10  20  60  70
Colville       39  38  46  40  43  22 /  50  60  50  50  70  30
Sandpoint      39  38  45  38  42  26 /  70  70  60  70  80  80
Kellogg        42  40  44  39  41  30 /  60  60  70  60  90 100
Moses Lake     48  44  55  41  51  27 /   0  10  10  20  30  30
Wenatchee      46  42  50  41  48  29 /  10  10  10  30  30  20
Omak           39  38  46  37  41  16 /  20  30  30  20  20  20

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...Dense Fog Advisory until 4 PM PST this afternoon for Spokane
     Area-Upper Columbia Basin-Waterville Plateau.

&&

$$




000
FXUS66 KSEW 261832 AAA
AFDSEW

AREA FORECAST DISCUSSION...UPDATED ADDED AVN MAR SECTIONS
NATIONAL WEATHER SERVICE SEATTLE WA
1032 AM PST WED NOV 26 2014

.SYNOPSIS...A WARM FRONT WILL REMAIN NEAR THE CANADIAN BORDER TODAY.
A COLD FRONT WILL MOVE EAST ACROSS THE AREA TONIGHT FOR MORE RAIN
AND WINDY CONDITIONS. RAIN WILL CONTINUE ON THANKSGIVING DAY AS
ANOTHER COLD FRONT APPROACHES FROM THE NORTH THEN CROSSES THE AREA
ON FRIDAY. A COLD UPPER LEVEL TROUGH WILL BE OVER THE AREA FRIDAY
NIGHT AND SATURDAY FOR A CHANCE OF SHOWERS...POSSIBLY MIXED WITH
SNOW. COOL DRY AND BREEZY WEATHER WILL DEVELOP SATURDAY NIGHT AND
SUNDAY AS HIGH PRESSURE BUILDS OVER BRITISH COLUMBIA.

&&

.SHORT TERM...WESTERN WASHINGTON IS IN THE WARM SECTOR OF A WARM
FRONT THAT IS NEARLY STATIONARY OVER SOUTHERN B.C. THIS MORNING.
TEMPERATURES WERE RATHER MILD OVERNIGHT FROM THE GREATER PUGET SOUND
REGION SOUTHWARD...AND REMAIN SO THIS MORNING WITH READINGS IN THE
MID TO UPPER 50S. THE WARM AIR HAS NOT QUITE REACHED THE NW INTERIOR
WHERE TEMPS WERE STILL IN THE UPPER 40S...BUT SHOULD GET THERE
EVENTUALLY TODAY. THE LULL IN RAIN WILL CONTINUE UNTIL THE NEXT
FRONT ARRIVES TONIGHT.

THE APPROACHING FRONT WAS OFFSHORE NEARING 130W AT 16Z/8 AM THIS
MORNING AND IS EXPECTED TO CROSS THE COAST AROUND 06Z/10 PM TONIGHT.
FROPA OVER THE INTERIOR SHOULD BE BEFORE 12Z/4 AM. S-SE SURFACE
WINDS WILL INCREASE AHEAD OF THE FRONT LATE THIS AFTERNOON AND
EVENING. STRONGEST WINDS SHOULD PEAK THIS EVENING IN THE LOW END
WIND ADVISORY RANGE FOR THE USUAL AREAS...COAST AND N INTERIOR.
WINDS WILL DIMINISH AFTER MIDNIGHT AS THE FRONT MOVES INLAND.

IN ADDITION...STRONG SW LOW LEVEL FLOW ALOFT AT 850 MB IS EXPECTED
TO DEVELOP AS THE FRONT APPROACHES THIS EVENING THEN CONTINUE IN THE
35-45KT RANGE THROUGH THURSDAY NIGHT AS A COLD FRONT OVER B.C. MOVES
S. THE SW FLOW WILL IMPACT MAINLY THE OLYMPICS AND N CASCADES WITH
HEAVY RAIN...WITH WIDESPREAD 3 INCH AMOUNTS AND A BULLSEYE OF AROUND
5 INCHES AROUND MT BAKER FOR THE 36 HOUR PERIOD 00Z THURSDAY THROUGH
12Z FRIDAY. SNOW LEVELS WILL REMAIN HIGH...6000 TO 7000 FEET TONIGHT
LOWERING TO 5000-6000 FEET THURSDAY NIGHT. THE HEAVY RAIN HAS A GOOD
CHANCE OF PRODUCING SOME FLOODING ON SOME OF THE RIVERS FLOWING OFF
THE N CASCADES. A FLOOD WATCH REMAINS IN EFFECT...SEE THE HYDRO
SECTION BELOW FOR MORE DETAILS.

AFTER TONIGHTS FRONT EXITS THE AREA EARLY THURSDAY MORNING...THE OLD
WARM FRONT OVER SOUTHERN B.C. WILL BE DRIVEN SOUTH ACROSS W WA AS A
COLD FRONT...BY A STRONG UPPER LEVEL TROUGH DIVING SOUTH FROM
NORTHERN B.C.  MODELS BRING THE BACK EDGE OF THE FRONT TO THE N
INTERIOR FRIDAY MORNING...THEN DOWN ACROSS PUGET SOUND LATE FRIDAY
AFTERNOON...THEN FINALLY APPROACHING THE OREGON BORDER LATE FRIDAY
EVENING. RAIN WILL CONTINUE WITH THE FRONT AS IT MOVES S.

INTERESTING WEATHER WILL CONTINUE FRIDAY NIGHT. THE LOW LEVEL AIR
MASS WILL REMAIN MOIST. THE APPROACHING UPPER LEVEL TROUGH IS VERY
COLD ALOFT AND WILL GRADUALLY COOL THE AIR MASS ENOUGH OVERNIGHT SO
THAT RAIN AND SNOW MIXED OR JUST SNOW IS POSSIBLE BY LATE FRIDAY
NIGHT INTO SATURDAY MORNING. THE UPPER LEVEL TROUGH WILL PROVIDE
SOME LOW LEVEL INSTABILITY AND LIFT TO SUPPORT SHOWER ACTIVITY. IN
ADDITION WINDS WILL BE RIGHT FOR A CONVERGENCE ZONE TO FORM OVER
CENTRAL PUGET SOUND.

A STRONG SURFACE HIGH FORMING OVER THE B.C.INTERIOR WILL GENERATE
FRASER RIVER VALLEY OUTFLOW WINDS ON SATURDAY. THIS WILL SPREAD COOL
DRY LOW LEVEL AIR SOUTHWARD ACROSS W WA...WITH CLEARING FROM THE
NORTH SATURDAY AFTERNOON AND EVENING. THE NE WINDS COULD BE STRONG
ENOUGH TO REACH WIND ADVISORY CRITERIA OVER THE FAR N INTERIOR. THE
COLD AIR WILL LEAD TO LOWS IN THE 20S ACROSS W WA SUNDAY MORNING. KAM

.LONG TERM...PREVIOUS DISCUSSION FROM THE 330 AM AFD...LONG RANGE
MODELS SHOW A COOL AND DRY AIR MASS OVER WESTERN WA ON SUNDAY. HIGH
PRES OVER INTERIOR B.C. WILL MAINTAIN EASTERLY FLOW THROUGH THE
PASSES. LOWS SUNDAY MORNING WILL BE DOWN TO THE 20S TO LOWER 30S
ONCE AGAIN. HIGHS ARE ALSO BELOW NORMAL ON SUNDAY WITH UPPER 30S TO
LOWER 40S EXPECTED. MODELS WERE SHOWING SOME MOISTURE SPREADING
NORTH SUN NIGHT OR MON BUT THEY ARE NOW BACKING OFF ON THIS IDEA. SO
THE FORECAST IS NOW LOOKING DRIER OVER THIS PERIOD AS WELL. THE
FORECAST IS ALSO LOOKING DRIER THROUGH MIDWEEK NOW AS THE EURO TRIES
TO BUILD A RIDGE OVER THE PAC NW. 33

&&

.HYDROLOGY...A WARM FRONT LIFTED NORTH INTO SOUTHERN BRITISH
COLUMBIA THIS MORNING WHERE THE HEAVIER RAIN NOW RESIDES. THE
COASTAL RADAR IS PICKING UP SOME STEADY LIGHT RAIN CONCENTRATED
ALONG THE COAST AND W/SW SLOPES OF THE OLYMPICS. UP TO A COUPLE
TENTHS HAS FALLEN THE PAST 3 HOURS OVER THE OLYMPICS WITH THE
RAINFALL RATES CONTINUING A DOWNTREND. RAIN IS ALSO DECREASING
ACROSS THE N CASCADES WHERE UP TO 1 INCH FELL OVERNIGHT. RAIN IS NOW
IN A LULL ACROSS WRN WA AND ANY ADDITIONAL RAIN AMOUNTS SHOULD BE
LESS THAN A HALF INCH AND MOSTLY CONFINED TO THE CASCADES OF
WHATCOM/SKAGIT COUNTIES AND THE OLYMPICS. BECAUSE RAINFALL HAS
TAPERED...THE ODDS OF THE NOOKSACK AT CEDARVILLE REACHING FLOOD
TODAY ARE LOW BUT STILL NEEDS TO BE WATCHED. THE STILLAGUAMISH
REACHED FLOOD OVERNIGHT BUT IS ON THE DOWNTURN AND SHOULD FALL BELOW
FLOOD LATER TODAY.

THE SNOQUALMIE RIVER AT THE FALLS CRESTED EARLY THIS MORNING WITH
THE CREST MOVING DOWNSTREAM THROUGH CARNATION LATE THIS AFTERNOON.
FLOODING ON THE SNOQUALMIE WILL CONTINUE THROUGH TONIGHT. THE
SKYKOMISH RIVER RAN WITHIN A FOOT OF FLOOD STAGE EARLIER THIS
MORNING BUT IS NOW ON THE DOWNTURN. THE SNOHOMISH...WHICH IS FORMED
BY THE CONFLUENCE OF THE SKYKOMISH AND SNOQUALMIE RIVERS...COULD
HAVE SOME FLOODING LATER TODAY.

THE RIVERS THAT FLOW OFF MOUNT RAINIER ARE RECEDING. THE FLOODING
HAS ENDED FOR THE CARBON AND NISQUALLY RIVERS...BUT FLOODING WILL
CONTINUE FOR THE COWLITZ AND REACH OF THE PUYALLUP NEAR ORTING.

ANOTHER FRONT WILL BRING RENEWED RAINFALL TO WRN WA TONIGHT AND
THURSDAY...LOCALLY HEAVY IN THE MOUNTAINS. THE OLYMPICS AND NORTH
CASCADES WILL RECEIVE THE HEAVIEST RAINFALL...BUT LOCALLY UP TO 5
INCHES OVER MOUNT RAINIER AND SKYKOMISH-SNOQUALMIE-TOLT-SNOHOMISH
BASIN IS POSSIBLE TOO. THE SNOW LEVEL WILL BE 5500 TO 7000 FT FOR
MOST OF THE EVENT...THEN FALL ON FRIDAY AS A COLD FRONT MOVES
THROUGH FROM THE NORTHWEST AND PRECIPITATION DECREASES.

A MAJOR FLOODING EPISODE IS UNLIKELY...BUT THE RAINFALL COULD
CERTAINLY RENEW FLOODING ON THE RIVERS THAT FLOODED OR ALMOST
FLOODED AND SOME OTHER RIVERS COULD REACH FLOOD STAGE AS WELL. A
FLOOD WATCH REMAINS IN EFFECT THROUGH FRIDAY...WHICH INCLUDES ALL
THE COUNTIES WITH RIVERS FLOWING OFF THE WEST SLOPES OF THE CASCADES
AND MASON COUNTY FOR THE POSSIBILITY OF A FLOOD ON THE SKOKOMISH.

COLDER AND DRIER WEATHER IS LIKELY THIS WEEKEND...SO RIVERS SHOULD
RECEDE AND THE FLOOD THREAT WILL END FOR THE FORESEEABLE FUTURE.

MERCER

&&

.AVIATION...THE FLOW ALOFT IS STRONG AND FROM THE WEST. THE AIR MASS
IS RATHER MOIST AFTER THE PASSAGE OF A WARM FRONT. CIGS ARE MVFR TO
VFR ACROSS THE AREA TODAY AS THE LAST OF THE SHOWERS MOVE OUT. A
COLD FRONT IS TIMED TO MOVE THROUGH THE AREA OVERNIGHT
TONIGHT...CIGS WILL BE HIGHER JUST BEFORE FRONTAL PASSAGE AND THEN
FALL JUST AFTER FRONTAL PASSAGE TO LOW MVFR IN MOST AREAS. SLY
SURFACE WINDS WILL BE STRONG AND GUSTY WITH THE FRONT AND INTO THE
MORNING.

KSEA...SOUTH WIND INCREASING FROM 10 TO 12 KT TODAY TO 12 TO 14 KT
OVERNIGHT WITH GUSTS TO 20 KT DURING AND AFTER FRONTAL PASSAGE
AROUND 7 OR 8Z. CONDITIONS WILL DETERIORATE LATE TONIGHT AS THE NEXT
FRONTAL SYSTEM ARRIVES. JSMITH

&&

.MARINE...A COLD FRONT WILL APPROACH THE WATERS TODAY AND MOVE
ONSHORE TONIGHT. SMALL CRAFT ADVISORY SOUTHERLY WINDS WILL BE
COMMON IN MOST WATERS TODAY...THEN GALES FOR SOME WATERS TONIGHT AS
THE FRONT MOVES THROUGH. MODERATE TO STRONG ONSHORE FLOW WILL
PREVAIL BEHIND THE FRONT ON THURSDAY.

ANOTHER COLD FRONT WILL MOVE THROUGH THE WATERS EARLY FRIDAY. THIS
FRONT WILL BE FOLLOWED BY STRONG FRASER OUTFLOW IN THE NORTHERN
INLAND WATERS AND MODERATE NORTHERLY WINDS OVER THE OTHER WATERS
LATER FRIDAY INTO SATURDAY. JSMITH

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...FLOOD WATCHES AND WARNINGS IN EFFECT FOR PORTIONS OF
     WESTERN WASHINGTON.
PZ...SMALL CRAFT ADVISORY ALL WATERS.
    .SMALL CRAFT ADVISORY GRAYS HARBOR BAR FOR ROUGH BAR.
    .GALE WARNING COASTAL WATERS...ENTRANCES STRAIT OF JUAN DE
     FUCA...AND NORTHERN INLAND WATERS LATE THIS AFTERNOON AND
     TONIGHT.

&&

$$

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 261826
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
1026 AM PST WED NOV 26 2014

.SYNOPSIS...
Mild and breezy weather is expected today and Thanksgiving. By
late this morning, snow levels should rise above the mountain
passes. Motorists with plans to travel over the mountain passes
should experience good conditions this afternoon through Friday
afternoon. The arrival of a cold front Friday night into Saturday
will bring winter driving conditions to the mountain passes and
much cooler weather for the weekend.


&&

.DISCUSSION...
Morning update: We continue to delay rising snow levels along the
Canadian Border however despite on and off snow at locations like
Laurier, Bonners Ferry, and Metaline Falls accumulations look to
be primarily on grassy (non-road) surfaces. Therefore, the winter
weather advisories were allowed to expire at 10AM this morning.

Travel across the region looks to be most problematic along Hwy
20 over Sherman Pass and into the Okanogan and Methow Valleys
where 12-18 inches of snow fell over the last 36 hours. The main
roads look mainly wet via cams but many secondary roads will
likely still be dealing with slick, slushy conditions. Periods of
light snow will remain a possibility through today with most
accumulations remaining on non-road surfaces.

Areas of dense fog will be a larger concern region-wide and will
restrict visibilities at times. The worse conditions look to be
along Hwy 2 between Airway Heights and Wenatchee and at times in
and around Moses Lake. Nearly all valley locations north of Hwy 2
can also expect fog and low clouds as warmer air moves in aloft
and strengthens inversions.

Quite the contrast in temperatures expected today with 60s in the
foothills of the Blue Mtns and Snake River Valley while
communities near the Canadian Border remain socked in the 30s.


&&

.AVIATION...
18Z TAFS: Recent rain/snow and warming aloft will promote areas
of fog and low clouds across most terminals this morning with
improving conditions expected through this evening. Areas of
LIFR/IFR fog currently stretches across the Upper Columbia Basin
from KCOE to KMWH. Confidence is low regarding exact timing for
improvements but gusty S/SW winds in the lower Basin should
promote improving conditions KPUW-KLWS by 20Z then expanding N
through 06z. KMWH/KEAT will carry the lower probabilities for
clearing. The upper-level ridge will flatten tomorrow suppressing
the moist frontal boundary back south lowering cigs btwn 4-6K ft
agl and incr the threat for light rain.  /sb



&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        46  42  50  40  45  26 /  20  30  30  20  80  60
Coeur d`Alene  45  41  48  40  44  27 /  40  30  30  20  90  70
Pullman        53  44  53  42  48  31 /  10  30  30  20  80  80
Lewiston       57  47  58  45  52  37 /  10  10  10  20  70  80
Colville       39  38  46  38  42  20 /  50  60  50  40  80  10
Sandpoint      39  38  45  37  41  25 /  70  70  60  50  90  50
Kellogg        42  40  44  38  40  29 /  60  60  70  70  90  80
Moses Lake     48  44  55  40  50  25 /   0  10  10  10  30  20
Wenatchee      46  42  50  41  47  27 /  10  10  10  20  30  10
Omak           39  38  46  35  40  14 /  20  30  30  30  50  10

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&

$$




000
FXUS66 KOTX 261826
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
1026 AM PST WED NOV 26 2014

.SYNOPSIS...
Mild and breezy weather is expected today and Thanksgiving. By
late this morning, snow levels should rise above the mountain
passes. Motorists with plans to travel over the mountain passes
should experience good conditions this afternoon through Friday
afternoon. The arrival of a cold front Friday night into Saturday
will bring winter driving conditions to the mountain passes and
much cooler weather for the weekend.


&&

.DISCUSSION...
Morning update: We continue to delay rising snow levels along the
Canadian Border however despite on and off snow at locations like
Laurier, Bonners Ferry, and Metaline Falls accumulations look to
be primarily on grassy (non-road) surfaces. Therefore, the winter
weather advisories were allowed to expire at 10AM this morning.

Travel across the region looks to be most problematic along Hwy
20 over Sherman Pass and into the Okanogan and Methow Valleys
where 12-18 inches of snow fell over the last 36 hours. The main
roads look mainly wet via cams but many secondary roads will
likely still be dealing with slick, slushy conditions. Periods of
light snow will remain a possibility through today with most
accumulations remaining on non-road surfaces.

Areas of dense fog will be a larger concern region-wide and will
restrict visibilities at times. The worse conditions look to be
along Hwy 2 between Airway Heights and Wenatchee and at times in
and around Moses Lake. Nearly all valley locations north of Hwy 2
can also expect fog and low clouds as warmer air moves in aloft
and strengthens inversions.

Quite the contrast in temperatures expected today with 60s in the
foothills of the Blue Mtns and Snake River Valley while
communities near the Canadian Border remain socked in the 30s.


&&

.AVIATION...
18Z TAFS: Recent rain/snow and warming aloft will promote areas
of fog and low clouds across most terminals this morning with
improving conditions expected through this evening. Areas of
LIFR/IFR fog currently stretches across the Upper Columbia Basin
from KCOE to KMWH. Confidence is low regarding exact timing for
improvements but gusty S/SW winds in the lower Basin should
promote improving conditions KPUW-KLWS by 20Z then expanding N
through 06z. KMWH/KEAT will carry the lower probabilities for
clearing. The upper-level ridge will flatten tomorrow suppressing
the moist frontal boundary back south lowering cigs btwn 4-6K ft
agl and incr the threat for light rain.  /sb



&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        46  42  50  40  45  26 /  20  30  30  20  80  60
Coeur d`Alene  45  41  48  40  44  27 /  40  30  30  20  90  70
Pullman        53  44  53  42  48  31 /  10  30  30  20  80  80
Lewiston       57  47  58  45  52  37 /  10  10  10  20  70  80
Colville       39  38  46  38  42  20 /  50  60  50  40  80  10
Sandpoint      39  38  45  37  41  25 /  70  70  60  50  90  50
Kellogg        42  40  44  38  40  29 /  60  60  70  70  90  80
Moses Lake     48  44  55  40  50  25 /   0  10  10  10  30  20
Wenatchee      46  42  50  41  47  27 /  10  10  10  20  30  10
Omak           39  38  46  35  40  14 /  20  30  30  30  50  10

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&

$$





000
FXUS66 KPQR 261758
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
1000 AM PST WED NOV 26 2014

.SYNOPSIS...A WARM FRONT ACROSS WA THIS MORNING WILL SLOWLY LIFT
FURTHER N THROUGH TONIGHT...LEAVING THE FORECAST AREA IN A MILD AIR
MASS. A WEAK COLD FRONT WILL MOVE E ACROSS THE AREA TONIGHT BRINGING
BACK CHANCES FOR RAIN. A STRONGER COLD FRONT DROPPING DOWN FROM THE
N WILL MOVE THROUGH FRI NIGHT BRINGING COLDER WEATHER FOR THE
WEEKEND...WITH WINDS TURNING OFFSHORE SUN. SUN NIGHT AND MON A
SYSTEM COMING UP FROM THE S WILL ATTEMPT TO SPREAD SOME
PRECIPITATION UP OVER THE COLD AIR MASS LEFT OVER FROM THE WEEKEND.
&&

.SHORT TERM...RADAR AND SURFACE OBSERVATIONS SUGGEST MOST OF THE
RAIN ASSOCIATED WITH THE WARM FRONT ACROSS WA THIS MORNING WAS N OF
THE FORECAST AREA...SO WILL LEAVE JUST A LOW POP IN FOR TODAY N OF
THE COLUMBIA RIVER WHILE THE REST OF THE FORECAST AREA REMAINS DRY
AND IN THE WARM SECTOR TODAY. WITH THE REGION REMAINING IN THE WARM
SECTOR TODAY...EXPECT PERSISTENCE TYPE TEMPS TODAY TO BE THE BEST
BET...MEANING SOME MORE TEMPERATURE RECORDS MAY AGAIN BE IN JEOPARDY
TODAY.

REMAINDER OF SHORT TERM DISCUSSION UNCHANGED...THE ASSOCIATED COLD
FRONT APPROACHING 130W EARLY THIS MORNING WILL REACH THE COAST AND
BEGIN SPREADING ONSHORE TONIGHT FOR MORE RAIN AND SOME BRISK COASTAL
WINDS...BUT LIKELY STAYING BELOW HIGH WIND CRITERIA. THE FRONT WILL
CONTINUE MOVING THROUGH THE FORECAST AREA ON THANKSGIVING FOR MORE
RAIN AND LOCALLY BREEZY CONDITIONS. SNOW LEVELS WILL REMAIN QUITE
HIGH IN THE CASCADES.

THE FRONTAL BOUNDARY WILL STALL OVER THE AREA THURSDAY NIGHT BENEATH
CONFLUENT FLOW ALOFT AS THE SOUTHERN BRANCH OF THE JET MERGES WITH AN
INCREASING NORTHERN BRANCH OF THE JET. THIS WILL KEEP SOME RAIN GOING
OVER MUCH OF THE AREA THURSDAY NIGHT.

A SECONDARY COLDER COLD FRONT WILL BEGIN SAGGING INTO OUR AREA FROM
THE NORTH ON FRIDAY...MERGING WITH THE STALLED SOUTHERN COLD
FRONT...AND KEEPING THE RAIN GOING...PERHAPS A LITTLE HEAVIER THAN ON
PREVIOUS DAYS. SNOW LEVELS IN THE SOUTH WASHINGTON CASCADES MAY BEGIN
TO FALL LATE IN THE DAY AS THIS SECONDARY COLD FRONT MOVES SOUTH BUT
SNOW LEVELS WILL GENERALLY STAY ABOVE THE PASS LEVELS THROUGH FRIDAY.
TOLLESON

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
FRIDAY NIGHT THROUGH TUESDAY...COMPLICATED PATTERN EVOLVES FRIDAY
NIGHT AND SAT WITH THE COLDER AIR CONTINUING TO SLIDE S THROUGH WA
AND INTO NRN OREGON. 12Z GFS MORE IN LINE WITH THE PREVIOUS COUPLE OF
ECMWF RUNS...DEPICTING A COLD AIR WEDGE IN THE CENTRAL COLUMBIA GORGE
BY 00Z SUN. LOOK FOR THE EAST WIND TO RETURN AS WELL...BEGINNING SAT
MORNING AND CONTINUING THROUGH THE WEEKEND. BY 00Z SUN THE GFS HAS -8
TO -10C 850 MB AIR IN THE CENTRAL COLUMBIA GORGE...WHILE THE ECMWF IS
JUST A TOUCH WARMER. FORTUNATELY...THE DRIER NLY FLOW WILL SHUNT
PRECIP FURTHER TO THE S. A CLOSED LOW WELL OF THE NRN CA COAST SAT
STARTS TO DRIFT NE SAT NIGHT AND SUN. THERE IS THE POTENTIAL FOR A
DEFORMATION BAND OVER NRN CA TO DRIFT NWD LATE SUN INTO MON. THIS
COULD BE PROBLEMATIC AS THE MOISTURE OVERRUNS THE COLD
AIR....ESPECIALLY FOR THE COLUMBIA GORGE AND UPPER HOOD RIVER VALLEY.
WEISHAAR
&&

.AVIATION...GENERALLY VFR ACROSS THE AREA AS OF 17Z...EXCEPT FOR
AREAS OF IFR ALONG THE N OREGON AND S WA COAST. EXPECT VFR TO
PREVAIL THROUGH AT LEAST THE EVENING HOURS. CIGS LOWER ALONG THE
COAST AFTER 03Z THU AS A COLD FRONT APPROACHES. LOOK FOR
CONDITIONS ALONG THE COAST TO FALL INTO MVFR BETWEEN 04Z TO 06Z
WITH PRECIP INCREASING OVERNIGHT. VFR SHOULD HOLD OVER THE INLAND
AREAS THROUGH AT LEAST 12Z THU...THEN MVFR CONDITIONS
INCREASE...WITH HIGHER TERRAIN BECOMING OBSCURED.

KPDX AND APPROACHES...VFR CONDITIONS TO PREVAIL THROUGH AT LEAST
12Z THU. RAIN DEVELOPS OVER WRN APPROACHES AROUND 10Z THEN SPREADS
E THEREAFTER...WITH LOCALIZED MVFR DEVELOPING AFTER 13Z. WEISHAAR

&&

.MARINE...WIND SPEEDS HOLDING AT 15 TO 20 KT THIS MORNING WITH
GUSTS UP TO 25 KT. SPEEDS RAMP UP THIS AFTERNOON AHEAD OF AN
APPROACHING FRONTAL SYSTEM. SHOULD SEE GALE FORCE WIND GUSTS OVER
MUCH OF THE WATERS BY LATE THIS AFTERNOON...BUT MORE SO IN THE 02Z
TO 08Z TIME FRAME. ALTHOUGH NOT A CLASSIC CASE...SOME MODEL
GUIDANCE IS SUGGESTING THE POTENTIAL FOR SOME COASTAL JET
ENHANCEMENT WITHIN 20 NM. COULD SEE SOME GUSTS UP TO 40 KT IF THIS
OCCURS. HIGH-END SMALL CRAFT ADVISORY SPEEDS PERSIST THU MORNING.
LATEST MODEL RUNS SHOW 20-25 KT NW WIND DEVELOPING OVER THE N
WATERS FRI EVENING THEN SPREADING FURTHER S OVERNIGHT. WIND TURNS
OFFSHORE OVER THE WEEKEND WITH POTENTIAL GUSTS 20 TO 30 KT NEAR
GAPS IN THE COASTAL TERRAIN.

SEAS EXPECTED TO BUILD TO 10 FT LATER TODAY THEN STAY ABOVE 10 FT
THROUGH AT LEAST FRI NIGHT. WEISHAAR

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 PM PST THIS AFTERNOON FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     GALE WARNING FROM 4 PM THIS AFTERNOON TO 4 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 4 PM THIS
     AFTERNOON TO 10 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 261758
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
1000 AM PST WED NOV 26 2014

.SYNOPSIS...A WARM FRONT ACROSS WA THIS MORNING WILL SLOWLY LIFT
FURTHER N THROUGH TONIGHT...LEAVING THE FORECAST AREA IN A MILD AIR
MASS. A WEAK COLD FRONT WILL MOVE E ACROSS THE AREA TONIGHT BRINGING
BACK CHANCES FOR RAIN. A STRONGER COLD FRONT DROPPING DOWN FROM THE
N WILL MOVE THROUGH FRI NIGHT BRINGING COLDER WEATHER FOR THE
WEEKEND...WITH WINDS TURNING OFFSHORE SUN. SUN NIGHT AND MON A
SYSTEM COMING UP FROM THE S WILL ATTEMPT TO SPREAD SOME
PRECIPITATION UP OVER THE COLD AIR MASS LEFT OVER FROM THE WEEKEND.
&&

.SHORT TERM...RADAR AND SURFACE OBSERVATIONS SUGGEST MOST OF THE
RAIN ASSOCIATED WITH THE WARM FRONT ACROSS WA THIS MORNING WAS N OF
THE FORECAST AREA...SO WILL LEAVE JUST A LOW POP IN FOR TODAY N OF
THE COLUMBIA RIVER WHILE THE REST OF THE FORECAST AREA REMAINS DRY
AND IN THE WARM SECTOR TODAY. WITH THE REGION REMAINING IN THE WARM
SECTOR TODAY...EXPECT PERSISTENCE TYPE TEMPS TODAY TO BE THE BEST
BET...MEANING SOME MORE TEMPERATURE RECORDS MAY AGAIN BE IN JEOPARDY
TODAY.

REMAINDER OF SHORT TERM DISCUSSION UNCHANGED...THE ASSOCIATED COLD
FRONT APPROACHING 130W EARLY THIS MORNING WILL REACH THE COAST AND
BEGIN SPREADING ONSHORE TONIGHT FOR MORE RAIN AND SOME BRISK COASTAL
WINDS...BUT LIKELY STAYING BELOW HIGH WIND CRITERIA. THE FRONT WILL
CONTINUE MOVING THROUGH THE FORECAST AREA ON THANKSGIVING FOR MORE
RAIN AND LOCALLY BREEZY CONDITIONS. SNOW LEVELS WILL REMAIN QUITE
HIGH IN THE CASCADES.

THE FRONTAL BOUNDARY WILL STALL OVER THE AREA THURSDAY NIGHT BENEATH
CONFLUENT FLOW ALOFT AS THE SOUTHERN BRANCH OF THE JET MERGES WITH AN
INCREASING NORTHERN BRANCH OF THE JET. THIS WILL KEEP SOME RAIN GOING
OVER MUCH OF THE AREA THURSDAY NIGHT.

A SECONDARY COLDER COLD FRONT WILL BEGIN SAGGING INTO OUR AREA FROM
THE NORTH ON FRIDAY...MERGING WITH THE STALLED SOUTHERN COLD
FRONT...AND KEEPING THE RAIN GOING...PERHAPS A LITTLE HEAVIER THAN ON
PREVIOUS DAYS. SNOW LEVELS IN THE SOUTH WASHINGTON CASCADES MAY BEGIN
TO FALL LATE IN THE DAY AS THIS SECONDARY COLD FRONT MOVES SOUTH BUT
SNOW LEVELS WILL GENERALLY STAY ABOVE THE PASS LEVELS THROUGH FRIDAY.
TOLLESON

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
FRIDAY NIGHT THROUGH TUESDAY...COMPLICATED PATTERN EVOLVES FRIDAY
NIGHT AND SAT WITH THE COLDER AIR CONTINUING TO SLIDE S THROUGH WA
AND INTO NRN OREGON. 12Z GFS MORE IN LINE WITH THE PREVIOUS COUPLE OF
ECMWF RUNS...DEPICTING A COLD AIR WEDGE IN THE CENTRAL COLUMBIA GORGE
BY 00Z SUN. LOOK FOR THE EAST WIND TO RETURN AS WELL...BEGINNING SAT
MORNING AND CONTINUING THROUGH THE WEEKEND. BY 00Z SUN THE GFS HAS -8
TO -10C 850 MB AIR IN THE CENTRAL COLUMBIA GORGE...WHILE THE ECMWF IS
JUST A TOUCH WARMER. FORTUNATELY...THE DRIER NLY FLOW WILL SHUNT
PRECIP FURTHER TO THE S. A CLOSED LOW WELL OF THE NRN CA COAST SAT
STARTS TO DRIFT NE SAT NIGHT AND SUN. THERE IS THE POTENTIAL FOR A
DEFORMATION BAND OVER NRN CA TO DRIFT NWD LATE SUN INTO MON. THIS
COULD BE PROBLEMATIC AS THE MOISTURE OVERRUNS THE COLD
AIR....ESPECIALLY FOR THE COLUMBIA GORGE AND UPPER HOOD RIVER VALLEY.
WEISHAAR
&&

.AVIATION...GENERALLY VFR ACROSS THE AREA AS OF 17Z...EXCEPT FOR
AREAS OF IFR ALONG THE N OREGON AND S WA COAST. EXPECT VFR TO
PREVAIL THROUGH AT LEAST THE EVENING HOURS. CIGS LOWER ALONG THE
COAST AFTER 03Z THU AS A COLD FRONT APPROACHES. LOOK FOR
CONDITIONS ALONG THE COAST TO FALL INTO MVFR BETWEEN 04Z TO 06Z
WITH PRECIP INCREASING OVERNIGHT. VFR SHOULD HOLD OVER THE INLAND
AREAS THROUGH AT LEAST 12Z THU...THEN MVFR CONDITIONS
INCREASE...WITH HIGHER TERRAIN BECOMING OBSCURED.

KPDX AND APPROACHES...VFR CONDITIONS TO PREVAIL THROUGH AT LEAST
12Z THU. RAIN DEVELOPS OVER WRN APPROACHES AROUND 10Z THEN SPREADS
E THEREAFTER...WITH LOCALIZED MVFR DEVELOPING AFTER 13Z. WEISHAAR

&&

.MARINE...WIND SPEEDS HOLDING AT 15 TO 20 KT THIS MORNING WITH
GUSTS UP TO 25 KT. SPEEDS RAMP UP THIS AFTERNOON AHEAD OF AN
APPROACHING FRONTAL SYSTEM. SHOULD SEE GALE FORCE WIND GUSTS OVER
MUCH OF THE WATERS BY LATE THIS AFTERNOON...BUT MORE SO IN THE 02Z
TO 08Z TIME FRAME. ALTHOUGH NOT A CLASSIC CASE...SOME MODEL
GUIDANCE IS SUGGESTING THE POTENTIAL FOR SOME COASTAL JET
ENHANCEMENT WITHIN 20 NM. COULD SEE SOME GUSTS UP TO 40 KT IF THIS
OCCURS. HIGH-END SMALL CRAFT ADVISORY SPEEDS PERSIST THU MORNING.
LATEST MODEL RUNS SHOW 20-25 KT NW WIND DEVELOPING OVER THE N
WATERS FRI EVENING THEN SPREADING FURTHER S OVERNIGHT. WIND TURNS
OFFSHORE OVER THE WEEKEND WITH POTENTIAL GUSTS 20 TO 30 KT NEAR
GAPS IN THE COASTAL TERRAIN.

SEAS EXPECTED TO BUILD TO 10 FT LATER TODAY THEN STAY ABOVE 10 FT
THROUGH AT LEAST FRI NIGHT. WEISHAAR

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 PM PST THIS AFTERNOON FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     GALE WARNING FROM 4 PM THIS AFTERNOON TO 4 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 4 PM THIS
     AFTERNOON TO 10 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 261758
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
1000 AM PST WED NOV 26 2014

.SYNOPSIS...A WARM FRONT ACROSS WA THIS MORNING WILL SLOWLY LIFT
FURTHER N THROUGH TONIGHT...LEAVING THE FORECAST AREA IN A MILD AIR
MASS. A WEAK COLD FRONT WILL MOVE E ACROSS THE AREA TONIGHT BRINGING
BACK CHANCES FOR RAIN. A STRONGER COLD FRONT DROPPING DOWN FROM THE
N WILL MOVE THROUGH FRI NIGHT BRINGING COLDER WEATHER FOR THE
WEEKEND...WITH WINDS TURNING OFFSHORE SUN. SUN NIGHT AND MON A
SYSTEM COMING UP FROM THE S WILL ATTEMPT TO SPREAD SOME
PRECIPITATION UP OVER THE COLD AIR MASS LEFT OVER FROM THE WEEKEND.
&&

.SHORT TERM...RADAR AND SURFACE OBSERVATIONS SUGGEST MOST OF THE
RAIN ASSOCIATED WITH THE WARM FRONT ACROSS WA THIS MORNING WAS N OF
THE FORECAST AREA...SO WILL LEAVE JUST A LOW POP IN FOR TODAY N OF
THE COLUMBIA RIVER WHILE THE REST OF THE FORECAST AREA REMAINS DRY
AND IN THE WARM SECTOR TODAY. WITH THE REGION REMAINING IN THE WARM
SECTOR TODAY...EXPECT PERSISTENCE TYPE TEMPS TODAY TO BE THE BEST
BET...MEANING SOME MORE TEMPERATURE RECORDS MAY AGAIN BE IN JEOPARDY
TODAY.

REMAINDER OF SHORT TERM DISCUSSION UNCHANGED...THE ASSOCIATED COLD
FRONT APPROACHING 130W EARLY THIS MORNING WILL REACH THE COAST AND
BEGIN SPREADING ONSHORE TONIGHT FOR MORE RAIN AND SOME BRISK COASTAL
WINDS...BUT LIKELY STAYING BELOW HIGH WIND CRITERIA. THE FRONT WILL
CONTINUE MOVING THROUGH THE FORECAST AREA ON THANKSGIVING FOR MORE
RAIN AND LOCALLY BREEZY CONDITIONS. SNOW LEVELS WILL REMAIN QUITE
HIGH IN THE CASCADES.

THE FRONTAL BOUNDARY WILL STALL OVER THE AREA THURSDAY NIGHT BENEATH
CONFLUENT FLOW ALOFT AS THE SOUTHERN BRANCH OF THE JET MERGES WITH AN
INCREASING NORTHERN BRANCH OF THE JET. THIS WILL KEEP SOME RAIN GOING
OVER MUCH OF THE AREA THURSDAY NIGHT.

A SECONDARY COLDER COLD FRONT WILL BEGIN SAGGING INTO OUR AREA FROM
THE NORTH ON FRIDAY...MERGING WITH THE STALLED SOUTHERN COLD
FRONT...AND KEEPING THE RAIN GOING...PERHAPS A LITTLE HEAVIER THAN ON
PREVIOUS DAYS. SNOW LEVELS IN THE SOUTH WASHINGTON CASCADES MAY BEGIN
TO FALL LATE IN THE DAY AS THIS SECONDARY COLD FRONT MOVES SOUTH BUT
SNOW LEVELS WILL GENERALLY STAY ABOVE THE PASS LEVELS THROUGH FRIDAY.
TOLLESON

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
FRIDAY NIGHT THROUGH TUESDAY...COMPLICATED PATTERN EVOLVES FRIDAY
NIGHT AND SAT WITH THE COLDER AIR CONTINUING TO SLIDE S THROUGH WA
AND INTO NRN OREGON. 12Z GFS MORE IN LINE WITH THE PREVIOUS COUPLE OF
ECMWF RUNS...DEPICTING A COLD AIR WEDGE IN THE CENTRAL COLUMBIA GORGE
BY 00Z SUN. LOOK FOR THE EAST WIND TO RETURN AS WELL...BEGINNING SAT
MORNING AND CONTINUING THROUGH THE WEEKEND. BY 00Z SUN THE GFS HAS -8
TO -10C 850 MB AIR IN THE CENTRAL COLUMBIA GORGE...WHILE THE ECMWF IS
JUST A TOUCH WARMER. FORTUNATELY...THE DRIER NLY FLOW WILL SHUNT
PRECIP FURTHER TO THE S. A CLOSED LOW WELL OF THE NRN CA COAST SAT
STARTS TO DRIFT NE SAT NIGHT AND SUN. THERE IS THE POTENTIAL FOR A
DEFORMATION BAND OVER NRN CA TO DRIFT NWD LATE SUN INTO MON. THIS
COULD BE PROBLEMATIC AS THE MOISTURE OVERRUNS THE COLD
AIR....ESPECIALLY FOR THE COLUMBIA GORGE AND UPPER HOOD RIVER VALLEY.
WEISHAAR
&&

.AVIATION...GENERALLY VFR ACROSS THE AREA AS OF 17Z...EXCEPT FOR
AREAS OF IFR ALONG THE N OREGON AND S WA COAST. EXPECT VFR TO
PREVAIL THROUGH AT LEAST THE EVENING HOURS. CIGS LOWER ALONG THE
COAST AFTER 03Z THU AS A COLD FRONT APPROACHES. LOOK FOR
CONDITIONS ALONG THE COAST TO FALL INTO MVFR BETWEEN 04Z TO 06Z
WITH PRECIP INCREASING OVERNIGHT. VFR SHOULD HOLD OVER THE INLAND
AREAS THROUGH AT LEAST 12Z THU...THEN MVFR CONDITIONS
INCREASE...WITH HIGHER TERRAIN BECOMING OBSCURED.

KPDX AND APPROACHES...VFR CONDITIONS TO PREVAIL THROUGH AT LEAST
12Z THU. RAIN DEVELOPS OVER WRN APPROACHES AROUND 10Z THEN SPREADS
E THEREAFTER...WITH LOCALIZED MVFR DEVELOPING AFTER 13Z. WEISHAAR

&&

.MARINE...WIND SPEEDS HOLDING AT 15 TO 20 KT THIS MORNING WITH
GUSTS UP TO 25 KT. SPEEDS RAMP UP THIS AFTERNOON AHEAD OF AN
APPROACHING FRONTAL SYSTEM. SHOULD SEE GALE FORCE WIND GUSTS OVER
MUCH OF THE WATERS BY LATE THIS AFTERNOON...BUT MORE SO IN THE 02Z
TO 08Z TIME FRAME. ALTHOUGH NOT A CLASSIC CASE...SOME MODEL
GUIDANCE IS SUGGESTING THE POTENTIAL FOR SOME COASTAL JET
ENHANCEMENT WITHIN 20 NM. COULD SEE SOME GUSTS UP TO 40 KT IF THIS
OCCURS. HIGH-END SMALL CRAFT ADVISORY SPEEDS PERSIST THU MORNING.
LATEST MODEL RUNS SHOW 20-25 KT NW WIND DEVELOPING OVER THE N
WATERS FRI EVENING THEN SPREADING FURTHER S OVERNIGHT. WIND TURNS
OFFSHORE OVER THE WEEKEND WITH POTENTIAL GUSTS 20 TO 30 KT NEAR
GAPS IN THE COASTAL TERRAIN.

SEAS EXPECTED TO BUILD TO 10 FT LATER TODAY THEN STAY ABOVE 10 FT
THROUGH AT LEAST FRI NIGHT. WEISHAAR

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 PM PST THIS AFTERNOON FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     GALE WARNING FROM 4 PM THIS AFTERNOON TO 4 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 4 PM THIS
     AFTERNOON TO 10 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 261758
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
1000 AM PST WED NOV 26 2014

.SYNOPSIS...A WARM FRONT ACROSS WA THIS MORNING WILL SLOWLY LIFT
FURTHER N THROUGH TONIGHT...LEAVING THE FORECAST AREA IN A MILD AIR
MASS. A WEAK COLD FRONT WILL MOVE E ACROSS THE AREA TONIGHT BRINGING
BACK CHANCES FOR RAIN. A STRONGER COLD FRONT DROPPING DOWN FROM THE
N WILL MOVE THROUGH FRI NIGHT BRINGING COLDER WEATHER FOR THE
WEEKEND...WITH WINDS TURNING OFFSHORE SUN. SUN NIGHT AND MON A
SYSTEM COMING UP FROM THE S WILL ATTEMPT TO SPREAD SOME
PRECIPITATION UP OVER THE COLD AIR MASS LEFT OVER FROM THE WEEKEND.
&&

.SHORT TERM...RADAR AND SURFACE OBSERVATIONS SUGGEST MOST OF THE
RAIN ASSOCIATED WITH THE WARM FRONT ACROSS WA THIS MORNING WAS N OF
THE FORECAST AREA...SO WILL LEAVE JUST A LOW POP IN FOR TODAY N OF
THE COLUMBIA RIVER WHILE THE REST OF THE FORECAST AREA REMAINS DRY
AND IN THE WARM SECTOR TODAY. WITH THE REGION REMAINING IN THE WARM
SECTOR TODAY...EXPECT PERSISTENCE TYPE TEMPS TODAY TO BE THE BEST
BET...MEANING SOME MORE TEMPERATURE RECORDS MAY AGAIN BE IN JEOPARDY
TODAY.

REMAINDER OF SHORT TERM DISCUSSION UNCHANGED...THE ASSOCIATED COLD
FRONT APPROACHING 130W EARLY THIS MORNING WILL REACH THE COAST AND
BEGIN SPREADING ONSHORE TONIGHT FOR MORE RAIN AND SOME BRISK COASTAL
WINDS...BUT LIKELY STAYING BELOW HIGH WIND CRITERIA. THE FRONT WILL
CONTINUE MOVING THROUGH THE FORECAST AREA ON THANKSGIVING FOR MORE
RAIN AND LOCALLY BREEZY CONDITIONS. SNOW LEVELS WILL REMAIN QUITE
HIGH IN THE CASCADES.

THE FRONTAL BOUNDARY WILL STALL OVER THE AREA THURSDAY NIGHT BENEATH
CONFLUENT FLOW ALOFT AS THE SOUTHERN BRANCH OF THE JET MERGES WITH AN
INCREASING NORTHERN BRANCH OF THE JET. THIS WILL KEEP SOME RAIN GOING
OVER MUCH OF THE AREA THURSDAY NIGHT.

A SECONDARY COLDER COLD FRONT WILL BEGIN SAGGING INTO OUR AREA FROM
THE NORTH ON FRIDAY...MERGING WITH THE STALLED SOUTHERN COLD
FRONT...AND KEEPING THE RAIN GOING...PERHAPS A LITTLE HEAVIER THAN ON
PREVIOUS DAYS. SNOW LEVELS IN THE SOUTH WASHINGTON CASCADES MAY BEGIN
TO FALL LATE IN THE DAY AS THIS SECONDARY COLD FRONT MOVES SOUTH BUT
SNOW LEVELS WILL GENERALLY STAY ABOVE THE PASS LEVELS THROUGH FRIDAY.
TOLLESON

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
FRIDAY NIGHT THROUGH TUESDAY...COMPLICATED PATTERN EVOLVES FRIDAY
NIGHT AND SAT WITH THE COLDER AIR CONTINUING TO SLIDE S THROUGH WA
AND INTO NRN OREGON. 12Z GFS MORE IN LINE WITH THE PREVIOUS COUPLE OF
ECMWF RUNS...DEPICTING A COLD AIR WEDGE IN THE CENTRAL COLUMBIA GORGE
BY 00Z SUN. LOOK FOR THE EAST WIND TO RETURN AS WELL...BEGINNING SAT
MORNING AND CONTINUING THROUGH THE WEEKEND. BY 00Z SUN THE GFS HAS -8
TO -10C 850 MB AIR IN THE CENTRAL COLUMBIA GORGE...WHILE THE ECMWF IS
JUST A TOUCH WARMER. FORTUNATELY...THE DRIER NLY FLOW WILL SHUNT
PRECIP FURTHER TO THE S. A CLOSED LOW WELL OF THE NRN CA COAST SAT
STARTS TO DRIFT NE SAT NIGHT AND SUN. THERE IS THE POTENTIAL FOR A
DEFORMATION BAND OVER NRN CA TO DRIFT NWD LATE SUN INTO MON. THIS
COULD BE PROBLEMATIC AS THE MOISTURE OVERRUNS THE COLD
AIR....ESPECIALLY FOR THE COLUMBIA GORGE AND UPPER HOOD RIVER VALLEY.
WEISHAAR
&&

.AVIATION...GENERALLY VFR ACROSS THE AREA AS OF 17Z...EXCEPT FOR
AREAS OF IFR ALONG THE N OREGON AND S WA COAST. EXPECT VFR TO
PREVAIL THROUGH AT LEAST THE EVENING HOURS. CIGS LOWER ALONG THE
COAST AFTER 03Z THU AS A COLD FRONT APPROACHES. LOOK FOR
CONDITIONS ALONG THE COAST TO FALL INTO MVFR BETWEEN 04Z TO 06Z
WITH PRECIP INCREASING OVERNIGHT. VFR SHOULD HOLD OVER THE INLAND
AREAS THROUGH AT LEAST 12Z THU...THEN MVFR CONDITIONS
INCREASE...WITH HIGHER TERRAIN BECOMING OBSCURED.

KPDX AND APPROACHES...VFR CONDITIONS TO PREVAIL THROUGH AT LEAST
12Z THU. RAIN DEVELOPS OVER WRN APPROACHES AROUND 10Z THEN SPREADS
E THEREAFTER...WITH LOCALIZED MVFR DEVELOPING AFTER 13Z. WEISHAAR

&&

.MARINE...WIND SPEEDS HOLDING AT 15 TO 20 KT THIS MORNING WITH
GUSTS UP TO 25 KT. SPEEDS RAMP UP THIS AFTERNOON AHEAD OF AN
APPROACHING FRONTAL SYSTEM. SHOULD SEE GALE FORCE WIND GUSTS OVER
MUCH OF THE WATERS BY LATE THIS AFTERNOON...BUT MORE SO IN THE 02Z
TO 08Z TIME FRAME. ALTHOUGH NOT A CLASSIC CASE...SOME MODEL
GUIDANCE IS SUGGESTING THE POTENTIAL FOR SOME COASTAL JET
ENHANCEMENT WITHIN 20 NM. COULD SEE SOME GUSTS UP TO 40 KT IF THIS
OCCURS. HIGH-END SMALL CRAFT ADVISORY SPEEDS PERSIST THU MORNING.
LATEST MODEL RUNS SHOW 20-25 KT NW WIND DEVELOPING OVER THE N
WATERS FRI EVENING THEN SPREADING FURTHER S OVERNIGHT. WIND TURNS
OFFSHORE OVER THE WEEKEND WITH POTENTIAL GUSTS 20 TO 30 KT NEAR
GAPS IN THE COASTAL TERRAIN.

SEAS EXPECTED TO BUILD TO 10 FT LATER TODAY THEN STAY ABOVE 10 FT
THROUGH AT LEAST FRI NIGHT. WEISHAAR

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 PM PST THIS AFTERNOON FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     GALE WARNING FROM 4 PM THIS AFTERNOON TO 4 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 4 PM THIS
     AFTERNOON TO 10 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 KSEW 261753
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
952 AM PST WED NOV 26 2014

.SYNOPSIS...A WARM FRONT WILL REMAIN NEAR THE CANADIAN BORDER TODAY.
A COLD FRONT WILL MOVE EAST ACROSS THE AREA TONIGHT FOR MORE RAIN
AND WINDY CONDITIONS. RAIN WILL CONTINUE ON THANKSGIVING DAY AS
ANOTHER COLD FRONT APPROACHES FROM THE NORTH THEN CROSSES THE AREA
ON FRIDAY. A COLD UPPER LEVEL TROUGH WILL BE OVER THE AREA FRIDAY
NIGHT AND SATURDAY FOR A CHANCE OF SHOWERS...POSSIBLY MIXED WITH
SNOW. COOL DRY AND BREEZY WEATHER WILL DEVELOP SATURDAY NIGHT AND
SUNDAY AS HIGH PRESSURE BUILDS OVER BRITISH COLUMBIA.

&&

.SHORT TERM...WESTERN WASHINGTON IS IN THE WARM SECTOR OF A WARM
FRONT THAT IS NEARLY STATIONARY OVER SOUTHERN B.C. THIS MORNING.
TEMPERATURES WERE RATHER MILD OVERNIGHT FROM THE GREATER PUGET SOUND
REGION SOUTHWARD...AND REMAIN SO THIS MORNING WITH READINGS IN THE
MID TO UPPER 50S. THE WARM AIR HAS NOT QUITE REACHED THE NW INTERIOR
WHERE TEMPS WERE STILL IN THE UPPER 40S...BUT SHOULD GET THERE
EVENTUALLY TODAY. THE LULL IN RAIN WILL CONTINUE UNTIL THE NEXT
FRONT ARRIVES TONIGHT.

THE APPROACHING FRONT WAS OFFSHORE NEARING 130W AT 16Z/8 AM THIS
MORNING AND IS EXPECTED TO CROSS THE COAST AROUND 06Z/10 PM TONIGHT.
FROPA OVER THE INTERIOR SHOULD BE BEFORE 12Z/4 AM. S-SE SURFACE
WINDS WILL INCREASE AHEAD OF THE FRONT LATE THIS AFTERNOON AND
EVENING. STRONGEST WINDS SHOULD PEAK THIS EVENING IN THE LOW END
WIND ADVISORY RANGE FOR THE USUAL AREAS...COAST AND N INTERIOR.
WINDS WILL DIMINISH AFTER MIDNIGHT AS THE FRONT MOVES INLAND.

IN ADDITION...STRONG SW LOW LEVEL FLOW ALOFT AT 850 MB IS EXPECTED
TO DEVELOP AS THE FRONT APPROACHES THIS EVENING THEN CONTINUE IN THE
35-45KT RANGE THROUGH THURSDAY NIGHT AS A COLD FRONT OVER B.C. MOVES
S. THE SW FLOW WILL IMPACT MAINLY THE OLYMPICS AND N CASCADES WITH
HEAVY RAIN...WITH WIDESPREAD 3 INCH AMOUNTS AND A BULLSEYE OF AROUND
5 INCHES AROUND MT BAKER FOR THE 36 HOUR PERIOD 00Z THURSDAY THROUGH
12Z FRIDAY. SNOW LEVELS WILL REMAIN HIGH...6000 TO 7000 FEET TONIGHT
LOWERING TO 5000-6000 FEET THURSDAY NIGHT. THE HEAVY RAIN HAS A GOOD
CHANCE OF PRODUCING SOME FLOODING ON SOME OF THE RIVERS FLOWING OFF
THE N CASCADES. A FLOOD WATCH REMAINS IN EFFECT...SEE THE HYDRO
SECTION BELOW FOR MORE DETAILS.

AFTER TONIGHTS FRONT EXITS THE AREA EARLY THURSDAY MORNING...THE OLD
WARM FRONT OVER SOUTHERN B.C. WILL BE DRIVEN SOUTH ACROSS W WA AS A
COLD FRONT...BY A STRONG UPPER LEVEL TROUGH DIVING SOUTH FROM
NORTHERN B.C.  MODELS BRING THE BACK EDGE OF THE FRONT TO THE N
INTERIOR FRIDAY MORNING...THEN DOWN ACROSS PUGET SOUND LATE FRIDAY
AFTERNOON...THEN FINALLY APPROACHING THE OREGON BORDER LATE FRIDAY
EVENING. RAIN WILL CONTINUE WITH THE FRONT AS IT MOVES S.

INTERESTING WEATHER WILL CONTINUE FRIDAY NIGHT. THE LOW LEVEL AIR
MASS WILL REMAIN MOIST. THE APPROACHING UPPER LEVEL TROUGH IS VERY
COLD ALOFT AND WILL GRADUALLY COOL THE AIR MASS ENOUGH OVERNIGHT SO
THAT RAIN AND SNOW MIXED OR JUST SNOW IS POSSIBLE BY LATE FRIDAY
NIGHT INTO SATURDAY MORNING. THE UPPER LEVEL TROUGH WILL PROVIDE
SOME LOW LEVEL INSTABILITY AND LIFT TO SUPPORT SHOWER ACTIVITY. IN
ADDITION WINDS WILL BE RIGHT FOR A CONVERGENCE ZONE TO FORM OVER
CENTRAL PUGET SOUND.

A STRONG SURFACE HIGH FORMING OVER THE B.C.INTERIOR WILL GENERATE
FRASER RIVER VALLEY OUTFLOW WINDS ON SATURDAY. THIS WILL SPREAD COOL
DRY LOW LEVEL AIR SOUTHWARD ACROSS W WA...WITH CLEARING FROM THE
NORTH SATURDAY AFTERNOON AND EVENING. THE NE WINDS COULD BE STRONG
ENOUGH TO REACH WIND ADVISORY CRITERIA OVER THE FAR N INTERIOR. THE
COLD AIR WILL LEAD TO LOWS IN THE 20S ACROSS W WA SUNDAY MORNING. KAM

.LONG TERM...PREVIOUS DISCUSSION FROM THE 330 AM AFD...LONG RANGE
MODELS SHOW A COOL AND DRY AIR MASS OVER WESTERN WA ON SUNDAY. HIGH
PRES OVER INTERIOR B.C. WILL MAINTAIN EASTERLY FLOW THROUGH THE
PASSES. LOWS SUNDAY MORNING WILL BE DOWN TO THE 20S TO LOWER 30S
ONCE AGAIN. HIGHS ARE ALSO BELOW NORMAL ON SUNDAY WITH UPPER 30S TO
LOWER 40S EXPECTED. MODELS WERE SHOWING SOME MOISTURE SPREADING
NORTH SUN NIGHT OR MON BUT THEY ARE NOW BACKING OFF ON THIS IDEA. SO
THE FORECAST IS NOW LOOKING DRIER OVER THIS PERIOD AS WELL. THE
FORECAST IS ALSO LOOKING DRIER THROUGH MIDWEEK NOW AS THE EURO TRIES
TO BUILD A RIDGE OVER THE PAC NW. 33

&&

.HYDROLOGY...A WARM FRONT LIFTED NORTH INTO SOUTHERN BRITISH
COLUMBIA THIS MORNING WHERE THE HEAVIER RAIN NOW RESIDES. THE
COASTAL RADAR IS PICKING UP SOME STEADY LIGHT RAIN CONCENTRATED
ALONG THE COAST AND W/SW SLOPES OF THE OLYMPICS. UP TO A COUPLE
TENTHS HAS FALLEN THE PAST 3 HOURS OVER THE OLYMPICS WITH THE
RAINFALL RATES CONTINUING A DOWNTREND. RAIN IS ALSO DECREASING
ACROSS THE N CASCADES WHERE UP TO 1 INCH FELL OVERNIGHT. RAIN IS NOW
IN A LULL ACROSS WRN WA AND ANY ADDITIONAL RAIN AMOUNTS SHOULD BE
LESS THAN A HALF INCH AND MOSTLY CONFINED TO THE CASCADES OF
WHATCOM/SKAGIT COUNTIES AND THE OLYMPICS. BECAUSE RAINFALL HAS
TAPERED...THE ODDS OF THE NOOKSACK AT CEDARVILLE REACHING FLOOD
TODAY ARE LOW BUT STILL NEEDS TO BE WATCHED. THE STILLAGUAMISH
REACHED FLOOD OVERNIGHT BUT IS ON THE DOWNTURN AND SHOULD FALL BELOW
FLOOD LATER TODAY.

THE SNOQUALMIE RIVER AT THE FALLS CRESTED EARLY THIS MORNING WITH
THE CREST MOVING DOWNSTREAM THROUGH CARNATION LATE THIS AFTERNOON.
FLOODING ON THE SNOQUALMIE WILL CONTINUE THROUGH TONIGHT. THE
SKYKOMISH RIVER RAN WITHIN A FOOT OF FLOOD STAGE EARLIER THIS
MORNING BUT IS NOW ON THE DOWNTURN. THE SNOHOMISH...WHICH IS FORMED
BY THE CONFLUENCE OF THE SKYKOMISH AND SNOQUALMIE RIVERS...COULD
HAVE SOME FLOODING LATER TODAY.

THE RIVERS THAT FLOW OFF MOUNT RAINIER ARE RECEDING. THE FLOODING
HAS ENDED FOR THE CARBON AND NISQUALLY RIVERS...BUT FLOODING WILL
CONTINUE FOR THE COWLITZ AND REACH OF THE PUYALLUP NEAR ORTING.

ANOTHER FRONT WILL BRING RENEWED RAINFALL TO WRN WA TONIGHT AND
THURSDAY...LOCALLY HEAVY IN THE MOUNTAINS. THE OLYMPICS AND NORTH
CASCADES WILL RECEIVE THE HEAVIEST RAINFALL...BUT LOCALLY UP TO 5
INCHES OVER MOUNT RAINIER AND SKYKOMISH-SNOQUALMIE-TOLT-SNOHOMISH
BASIN IS POSSIBLE TOO. THE SNOW LEVEL WILL BE 5500 TO 7000 FT FOR
MOST OF THE EVENT...THEN FALL ON FRIDAY AS A COLD FRONT MOVES
THROUGH FROM THE NORTHWEST AND PRECIPITATION DECREASES.

A MAJOR FLOODING EPISODE IS UNLIKELY...BUT THE RAINFALL COULD
CERTAINLY RENEW FLOODING ON THE RIVERS THAT FLOODED OR ALMOST
FLOODED AND SOME OTHER RIVERS COULD REACH FLOOD STAGE AS WELL. A
FLOOD WATCH REMAINS IN EFFECT THROUGH FRIDAY...WHICH INCLUDES ALL
THE COUNTIES WITH RIVERS FLOWING OFF THE WEST SLOPES OF THE CASCADES
AND MASON COUNTY FOR THE POSSIBILITY OF A FLOOD ON THE SKOKOMISH.

COLDER AND DRIER WEATHER IS LIKELY THIS WEEKEND...SO RIVERS SHOULD
RECEDE AND THE FLOOD THREAT WILL END FOR THE FORESEEABLE FUTURE.

MERCER

&&

.AVIATION...DELAYED...THE WARM FRONT THAT BROUGHT ALL THE RAIN TO
WESTERN WASHINGTON THE PAST COUPLE DAYS HAS MOVED INTO BRITISH
COLUMBIA. HOWEVER A WARM MOIST AIR MASS REMAINS OVER WESTERN
WASHINGTON WITH WIDESPREAD LOW-END MVFR TO IFR
CONDITIONS...INCLUDING SOME VISIBILITIES BELOW 3SM IN FOG AND LIGHT
PRECIPITATION.

IMPROVEMENT TODAY WILL BE GRADUAL AND MAINLY LIMITED TO THE PUGET
SOUND REGION AND SOUTHWEST INTERIOR. ANOTHER VIGOROUS FRONTAL SYSTEM
WILL BRING MORE RAIN TO THE COAST LATE TODAY...SPREADING INTO THE
WESTERN WASHINGTON INTERIOR THIS EVENING. WHATEVER IMPROVEMENT
OCCURS TODAY IS LIKELY TO BE QUICKLY UNDONE AS A RESULT.

KSEA...SOUTH WIND MOSTLY 10-16 KT GUSTING 24 KT THROUGH TONIGHT...
EXCEPT THERE COULD BE A BRIEF LULL LATE THIS MORNING AND AFTERNOON.
THE GRADUAL IMPROVEMENT IN CEILINGS SHOULD CONTINUE TODAY...BUT
CONDITIONS WILL DETERIORATE TONIGHT AS THE NEXT FRONTAL SYSTEM
ARRIVES.   MCDONNAL

&&

.MARINE...DELAYED...A COLD FRONT WILL APPROACH THE WATERS TODAY AND
MOVE ONSHORE TONIGHT. SMALL CRAFT ADVISORY SOUTHERLY WINDS WILL BE
COMMON MOST WATERS TODAY...THEN GALES FOR SOME WATERS TONIGHT AS THE
FRONT MOVES THROUGH. MODERATE TO STRONG ONSHORE FLOW WILL PREVAIL
BEHIND THE FRONT ON THURSDAY.

ANOTHER COLD FRONT WILL MOVE THROUGH THE WATERS ON FRIDAY. THIS
FRONT WILL BE FOLLOWED BY STRONG FRASER OUTFLOW IN THE NORTHERN
INLAND WATERS AND MODERATE NORTHERLY WINDS OVER THE OTHER WATERS
LATER FRIDAY INTO SATURDAY. SCHNEIDER

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...FLOOD WATCHES AND WARNINGS IN EFFECT FOR PORTIONS OF
     WESTERN WASHINGTON.
PZ...SMALL CRAFT ADVISORY ALL WATERS.
    .SMALL CRAFT ADVISORY GRAYS HARBOR BAR FOR ROUGH BAR.
    .GALE WARNING COASTAL WATERS...ENTRANCES STRAIT OF JUAN DE
     FUCA...AND NORTHERN INLAND WATERS LATE THIS AFTERNOON AND
     TONIGHT.

&&

$$

WWW.WEATHER.GOV/SEATTLE

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000
FXUS66 KSEW 261753
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
952 AM PST WED NOV 26 2014

.SYNOPSIS...A WARM FRONT WILL REMAIN NEAR THE CANADIAN BORDER TODAY.
A COLD FRONT WILL MOVE EAST ACROSS THE AREA TONIGHT FOR MORE RAIN
AND WINDY CONDITIONS. RAIN WILL CONTINUE ON THANKSGIVING DAY AS
ANOTHER COLD FRONT APPROACHES FROM THE NORTH THEN CROSSES THE AREA
ON FRIDAY. A COLD UPPER LEVEL TROUGH WILL BE OVER THE AREA FRIDAY
NIGHT AND SATURDAY FOR A CHANCE OF SHOWERS...POSSIBLY MIXED WITH
SNOW. COOL DRY AND BREEZY WEATHER WILL DEVELOP SATURDAY NIGHT AND
SUNDAY AS HIGH PRESSURE BUILDS OVER BRITISH COLUMBIA.

&&

.SHORT TERM...WESTERN WASHINGTON IS IN THE WARM SECTOR OF A WARM
FRONT THAT IS NEARLY STATIONARY OVER SOUTHERN B.C. THIS MORNING.
TEMPERATURES WERE RATHER MILD OVERNIGHT FROM THE GREATER PUGET SOUND
REGION SOUTHWARD...AND REMAIN SO THIS MORNING WITH READINGS IN THE
MID TO UPPER 50S. THE WARM AIR HAS NOT QUITE REACHED THE NW INTERIOR
WHERE TEMPS WERE STILL IN THE UPPER 40S...BUT SHOULD GET THERE
EVENTUALLY TODAY. THE LULL IN RAIN WILL CONTINUE UNTIL THE NEXT
FRONT ARRIVES TONIGHT.

THE APPROACHING FRONT WAS OFFSHORE NEARING 130W AT 16Z/8 AM THIS
MORNING AND IS EXPECTED TO CROSS THE COAST AROUND 06Z/10 PM TONIGHT.
FROPA OVER THE INTERIOR SHOULD BE BEFORE 12Z/4 AM. S-SE SURFACE
WINDS WILL INCREASE AHEAD OF THE FRONT LATE THIS AFTERNOON AND
EVENING. STRONGEST WINDS SHOULD PEAK THIS EVENING IN THE LOW END
WIND ADVISORY RANGE FOR THE USUAL AREAS...COAST AND N INTERIOR.
WINDS WILL DIMINISH AFTER MIDNIGHT AS THE FRONT MOVES INLAND.

IN ADDITION...STRONG SW LOW LEVEL FLOW ALOFT AT 850 MB IS EXPECTED
TO DEVELOP AS THE FRONT APPROACHES THIS EVENING THEN CONTINUE IN THE
35-45KT RANGE THROUGH THURSDAY NIGHT AS A COLD FRONT OVER B.C. MOVES
S. THE SW FLOW WILL IMPACT MAINLY THE OLYMPICS AND N CASCADES WITH
HEAVY RAIN...WITH WIDESPREAD 3 INCH AMOUNTS AND A BULLSEYE OF AROUND
5 INCHES AROUND MT BAKER FOR THE 36 HOUR PERIOD 00Z THURSDAY THROUGH
12Z FRIDAY. SNOW LEVELS WILL REMAIN HIGH...6000 TO 7000 FEET TONIGHT
LOWERING TO 5000-6000 FEET THURSDAY NIGHT. THE HEAVY RAIN HAS A GOOD
CHANCE OF PRODUCING SOME FLOODING ON SOME OF THE RIVERS FLOWING OFF
THE N CASCADES. A FLOOD WATCH REMAINS IN EFFECT...SEE THE HYDRO
SECTION BELOW FOR MORE DETAILS.

AFTER TONIGHTS FRONT EXITS THE AREA EARLY THURSDAY MORNING...THE OLD
WARM FRONT OVER SOUTHERN B.C. WILL BE DRIVEN SOUTH ACROSS W WA AS A
COLD FRONT...BY A STRONG UPPER LEVEL TROUGH DIVING SOUTH FROM
NORTHERN B.C.  MODELS BRING THE BACK EDGE OF THE FRONT TO THE N
INTERIOR FRIDAY MORNING...THEN DOWN ACROSS PUGET SOUND LATE FRIDAY
AFTERNOON...THEN FINALLY APPROACHING THE OREGON BORDER LATE FRIDAY
EVENING. RAIN WILL CONTINUE WITH THE FRONT AS IT MOVES S.

INTERESTING WEATHER WILL CONTINUE FRIDAY NIGHT. THE LOW LEVEL AIR
MASS WILL REMAIN MOIST. THE APPROACHING UPPER LEVEL TROUGH IS VERY
COLD ALOFT AND WILL GRADUALLY COOL THE AIR MASS ENOUGH OVERNIGHT SO
THAT RAIN AND SNOW MIXED OR JUST SNOW IS POSSIBLE BY LATE FRIDAY
NIGHT INTO SATURDAY MORNING. THE UPPER LEVEL TROUGH WILL PROVIDE
SOME LOW LEVEL INSTABILITY AND LIFT TO SUPPORT SHOWER ACTIVITY. IN
ADDITION WINDS WILL BE RIGHT FOR A CONVERGENCE ZONE TO FORM OVER
CENTRAL PUGET SOUND.

A STRONG SURFACE HIGH FORMING OVER THE B.C.INTERIOR WILL GENERATE
FRASER RIVER VALLEY OUTFLOW WINDS ON SATURDAY. THIS WILL SPREAD COOL
DRY LOW LEVEL AIR SOUTHWARD ACROSS W WA...WITH CLEARING FROM THE
NORTH SATURDAY AFTERNOON AND EVENING. THE NE WINDS COULD BE STRONG
ENOUGH TO REACH WIND ADVISORY CRITERIA OVER THE FAR N INTERIOR. THE
COLD AIR WILL LEAD TO LOWS IN THE 20S ACROSS W WA SUNDAY MORNING. KAM

.LONG TERM...PREVIOUS DISCUSSION FROM THE 330 AM AFD...LONG RANGE
MODELS SHOW A COOL AND DRY AIR MASS OVER WESTERN WA ON SUNDAY. HIGH
PRES OVER INTERIOR B.C. WILL MAINTAIN EASTERLY FLOW THROUGH THE
PASSES. LOWS SUNDAY MORNING WILL BE DOWN TO THE 20S TO LOWER 30S
ONCE AGAIN. HIGHS ARE ALSO BELOW NORMAL ON SUNDAY WITH UPPER 30S TO
LOWER 40S EXPECTED. MODELS WERE SHOWING SOME MOISTURE SPREADING
NORTH SUN NIGHT OR MON BUT THEY ARE NOW BACKING OFF ON THIS IDEA. SO
THE FORECAST IS NOW LOOKING DRIER OVER THIS PERIOD AS WELL. THE
FORECAST IS ALSO LOOKING DRIER THROUGH MIDWEEK NOW AS THE EURO TRIES
TO BUILD A RIDGE OVER THE PAC NW. 33

&&

.HYDROLOGY...A WARM FRONT LIFTED NORTH INTO SOUTHERN BRITISH
COLUMBIA THIS MORNING WHERE THE HEAVIER RAIN NOW RESIDES. THE
COASTAL RADAR IS PICKING UP SOME STEADY LIGHT RAIN CONCENTRATED
ALONG THE COAST AND W/SW SLOPES OF THE OLYMPICS. UP TO A COUPLE
TENTHS HAS FALLEN THE PAST 3 HOURS OVER THE OLYMPICS WITH THE
RAINFALL RATES CONTINUING A DOWNTREND. RAIN IS ALSO DECREASING
ACROSS THE N CASCADES WHERE UP TO 1 INCH FELL OVERNIGHT. RAIN IS NOW
IN A LULL ACROSS WRN WA AND ANY ADDITIONAL RAIN AMOUNTS SHOULD BE
LESS THAN A HALF INCH AND MOSTLY CONFINED TO THE CASCADES OF
WHATCOM/SKAGIT COUNTIES AND THE OLYMPICS. BECAUSE RAINFALL HAS
TAPERED...THE ODDS OF THE NOOKSACK AT CEDARVILLE REACHING FLOOD
TODAY ARE LOW BUT STILL NEEDS TO BE WATCHED. THE STILLAGUAMISH
REACHED FLOOD OVERNIGHT BUT IS ON THE DOWNTURN AND SHOULD FALL BELOW
FLOOD LATER TODAY.

THE SNOQUALMIE RIVER AT THE FALLS CRESTED EARLY THIS MORNING WITH
THE CREST MOVING DOWNSTREAM THROUGH CARNATION LATE THIS AFTERNOON.
FLOODING ON THE SNOQUALMIE WILL CONTINUE THROUGH TONIGHT. THE
SKYKOMISH RIVER RAN WITHIN A FOOT OF FLOOD STAGE EARLIER THIS
MORNING BUT IS NOW ON THE DOWNTURN. THE SNOHOMISH...WHICH IS FORMED
BY THE CONFLUENCE OF THE SKYKOMISH AND SNOQUALMIE RIVERS...COULD
HAVE SOME FLOODING LATER TODAY.

THE RIVERS THAT FLOW OFF MOUNT RAINIER ARE RECEDING. THE FLOODING
HAS ENDED FOR THE CARBON AND NISQUALLY RIVERS...BUT FLOODING WILL
CONTINUE FOR THE COWLITZ AND REACH OF THE PUYALLUP NEAR ORTING.

ANOTHER FRONT WILL BRING RENEWED RAINFALL TO WRN WA TONIGHT AND
THURSDAY...LOCALLY HEAVY IN THE MOUNTAINS. THE OLYMPICS AND NORTH
CASCADES WILL RECEIVE THE HEAVIEST RAINFALL...BUT LOCALLY UP TO 5
INCHES OVER MOUNT RAINIER AND SKYKOMISH-SNOQUALMIE-TOLT-SNOHOMISH
BASIN IS POSSIBLE TOO. THE SNOW LEVEL WILL BE 5500 TO 7000 FT FOR
MOST OF THE EVENT...THEN FALL ON FRIDAY AS A COLD FRONT MOVES
THROUGH FROM THE NORTHWEST AND PRECIPITATION DECREASES.

A MAJOR FLOODING EPISODE IS UNLIKELY...BUT THE RAINFALL COULD
CERTAINLY RENEW FLOODING ON THE RIVERS THAT FLOODED OR ALMOST
FLOODED AND SOME OTHER RIVERS COULD REACH FLOOD STAGE AS WELL. A
FLOOD WATCH REMAINS IN EFFECT THROUGH FRIDAY...WHICH INCLUDES ALL
THE COUNTIES WITH RIVERS FLOWING OFF THE WEST SLOPES OF THE CASCADES
AND MASON COUNTY FOR THE POSSIBILITY OF A FLOOD ON THE SKOKOMISH.

COLDER AND DRIER WEATHER IS LIKELY THIS WEEKEND...SO RIVERS SHOULD
RECEDE AND THE FLOOD THREAT WILL END FOR THE FORESEEABLE FUTURE.

MERCER

&&

.AVIATION...DELAYED...THE WARM FRONT THAT BROUGHT ALL THE RAIN TO
WESTERN WASHINGTON THE PAST COUPLE DAYS HAS MOVED INTO BRITISH
COLUMBIA. HOWEVER A WARM MOIST AIR MASS REMAINS OVER WESTERN
WASHINGTON WITH WIDESPREAD LOW-END MVFR TO IFR
CONDITIONS...INCLUDING SOME VISIBILITIES BELOW 3SM IN FOG AND LIGHT
PRECIPITATION.

IMPROVEMENT TODAY WILL BE GRADUAL AND MAINLY LIMITED TO THE PUGET
SOUND REGION AND SOUTHWEST INTERIOR. ANOTHER VIGOROUS FRONTAL SYSTEM
WILL BRING MORE RAIN TO THE COAST LATE TODAY...SPREADING INTO THE
WESTERN WASHINGTON INTERIOR THIS EVENING. WHATEVER IMPROVEMENT
OCCURS TODAY IS LIKELY TO BE QUICKLY UNDONE AS A RESULT.

KSEA...SOUTH WIND MOSTLY 10-16 KT GUSTING 24 KT THROUGH TONIGHT...
EXCEPT THERE COULD BE A BRIEF LULL LATE THIS MORNING AND AFTERNOON.
THE GRADUAL IMPROVEMENT IN CEILINGS SHOULD CONTINUE TODAY...BUT
CONDITIONS WILL DETERIORATE TONIGHT AS THE NEXT FRONTAL SYSTEM
ARRIVES.   MCDONNAL

&&

.MARINE...DELAYED...A COLD FRONT WILL APPROACH THE WATERS TODAY AND
MOVE ONSHORE TONIGHT. SMALL CRAFT ADVISORY SOUTHERLY WINDS WILL BE
COMMON MOST WATERS TODAY...THEN GALES FOR SOME WATERS TONIGHT AS THE
FRONT MOVES THROUGH. MODERATE TO STRONG ONSHORE FLOW WILL PREVAIL
BEHIND THE FRONT ON THURSDAY.

ANOTHER COLD FRONT WILL MOVE THROUGH THE WATERS ON FRIDAY. THIS
FRONT WILL BE FOLLOWED BY STRONG FRASER OUTFLOW IN THE NORTHERN
INLAND WATERS AND MODERATE NORTHERLY WINDS OVER THE OTHER WATERS
LATER FRIDAY INTO SATURDAY. SCHNEIDER

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...FLOOD WATCHES AND WARNINGS IN EFFECT FOR PORTIONS OF
     WESTERN WASHINGTON.
PZ...SMALL CRAFT ADVISORY ALL WATERS.
    .SMALL CRAFT ADVISORY GRAYS HARBOR BAR FOR ROUGH BAR.
    .GALE WARNING COASTAL WATERS...ENTRANCES STRAIT OF JUAN DE
     FUCA...AND NORTHERN INLAND WATERS LATE THIS AFTERNOON AND
     TONIGHT.

&&

$$

WWW.WEATHER.GOV/SEATTLE

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000
FXUS66 KOTX 261154
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
354 AM PST WED NOV 26 2014

.SYNOPSIS...
Mild and breezy weather is expected today and Thanksgiving. By
late this morning, snow levels should rise above the mountain
passes. Motorists with plans to travel over the mountain passes
should experience good conditions this afternoon through Friday
afternoon. The arrival of a cold front Friday night into Saturday
will bring winter driving conditions to the mountain passes and
much cooler weather for the weekend.

&&

.DISCUSSION...

Today: The axis of the heaviest precipitation will continue to
migrate northward today as the jet stream is shunted Alberta and
Montana. Forecasting snow levels in the northern Cascades,
northeast Washington and far north Idaho over the last 24 hour has
been brutal. There has been a tremendously tight gradient between
snow levels of 6000 feet in places like Stevens Pass and the
valley floor in the Methow Valley. Fortunately this morning,
precipitation amounts will not be as heavy as they were yesterday
afternoon and evening. An additional 1 to 3 inches of snow
accumulation is expected this morning over the Pasayten Wilderness
to Sherman Pass to the mountains near Sandpoint. Another inch or
two of accumulation will also be possible early this morning over
Lookout Pass before snow transitions to rain shortly after
sunrise. Winter Weather Advisories will remain in effect through
10 AM for Lookout Pass and the northern portions of Stevens, Pend
Oreille, Bonner and Boundary counties.

The temperature forecast has been lowered along the East Slopes of
the Cascades, Waterville Plateau into the Moses Lake area. Thick
low clouds and fog will likely linger for a good portion of the
day. For the Palouse, West Plains and Ritzville areas, south winds
of 10 to 15 mph should develop by late morning providing mixing to
warm temperatures into the 40s and 50s.

Tonight into Thanksgiving: Snow levels will be at or above 6000
feet for Idaho and Washington tonight into Thanksgiving. Mountain
passes will experience periods of rain during this busy holiday
travel period, but the roads should be in relatively good shape.
Thanksgiving has the potential to be one of the warmest days of
the month. Despite mostly cloudy conditions, breezy southwest
winds will provide the mixing needed this time of year to push
temperatures into the 50s over much of the region. /GKoch

Friday through Sunday night...The region will start out under a
relatively warm and wet pattern Friday then transition to a much
colder but drier regime over the weekend. Westerly flow aloft will
continue to direct a moisture laden fetch across the region
Friday. The areas most favored for precipitation will be the
Cascade crest and the rising terrain north and east of the
Columbia Basin. The entire eastern half of the forecast area will
likely see a decent amount of precip as a surface low tracks south
from southeast British Columbia into central Idaho by Saturday.
Right now models are generally tracking it through the Idaho
panhandle but the precise track will determine how far west into
the basin the precip will extend. QPF could easily top an inch or
two for north Idaho as the low slowly sinks south. Snow levels
will start out quite high, ranging from 5k to 7k ft. Only the
highest peaks will see snow on Friday.

An arctic front will drop south across the forecast area Friday night
and Saturday, bringing in much drier and colder air, chasing
precip to the southeast zones by Saturday evening. Plunging snow
levels will allow accumulating snow for the southeast valleys with
possible winter highlight criteria being achieved, particularly
for the Camas Prairie on Saturday. Temperatures will plummet
Friday night with single digits for the typical cold spots in the
northern valleys. Most locations will see a 20 to 30 degree drop
overnight with only the southernmost valleys escaping freezing
temps. As the low drops south, the building arctic high over BC
will strengthen the surface pressure gradient between them. Winds
will increase down the north-south valleys and be funneled down
the Purcell trench and into the west Plains and basin. Expect wind
chill temperatures below zero in the Okanogan valley where the
strongest winds and very cold temps will prevail.

Cold conditions will continue Saturday night and Sunday with much
of the forecast area remaining dry. The exception will be the
southernmost counties where the surface front will stall. Surface
winds will diminish but remain northerly, reinforcing the cold air
in the valleys. Southwest flow ahead of the next Pacific trough
will result in strong warm air advection in the mid levels for
Sunday night into Monday. This layer of warm air overrunning the
resident cold air at the surface could bring mixed precipitation
to the Columbia Basin, Wenatchee Valley, L-C valley and possibly
as far north as the Spokane area. Temperature profiles for the
northern valleys appear to be cold enough to support all snow.
/Kelch

Monday through Wednesday: An active weather pattern is expected to
continue through this period. The GFS has been more consistent
with pushing warm moist air mass form the Southwest into the
region compared with the ECMWF which is depicting a dry Northwest
flow. This set up is expected to bring widespread precip to the
region. Snow for most locations in the Inland Northwest excluding
the rain for the Palouse and Camas Prairie areas through Tuesday
morning. A small ridge is expected to begin to build in the region
on Tuesday and bring a decrease in the precip Columbia Basin and
continues snow to the Cascades, Idaho Panhandle, and Canadian
Border regions. Temperatures are expected to range from upper 20s
for highs and low teens for lows. /JDC

&&

.AVIATION...
12Z TAFS: A 24 hour rain event over much of the Inland Northwest
has left a soup of low stratus and fog. Deep surface low pressure
approaching Vancouver Island today will produce increasing
southwest winds over southeast Washington which should bring some
improvement to ceilings. Fog and stratus should lift at
Lewiston and Pullman this morning. Low level wind shear has been
included at Pullman prior to 17z. Nearby Alpowa summit is gusting
to 40 mph and NAM forecast sounding show strong winds at 2000 feet
off the deck. Cold air damming along the East Slopes of the
Cascades into the Moses Lake area could make ceiling and
visibility improvements very slow to evolve. The 12z TAFS show a
gradual lifting of the cloud deck, but this may be optimistic
looking at the dewpoints over the southern Columbia Basin which
will be advected into the cold stable air trapped along the East
Slopes. /GKoch


&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        45  42  50  40  45  26 /  80  30  30  20  80  60
Coeur d`Alene  44  41  48  40  44  27 /  90  30  30  20  90  70
Pullman        54  44  53  42  48  31 /  30  30  30  20  80  80
Lewiston       56  47  58  45  52  37 /  10  10  10  20  70  80
Colville       38  38  46  38  42  20 /  90  60  50  40  80  10
Sandpoint      39  38  45  37  41  25 / 100  70  60  50  90  50
Kellogg        43  40  44  38  40  29 / 100  60  70  70  90  80
Moses Lake     46  44  55  40  50  25 /  10  10  10  10  30  20
Wenatchee      43  42  50  41  47  27 /  10  10  10  20  30  10
Omak           38  38  46  35  40  14 /  50  30  30  30  50  10

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Winter Weather Advisory until 10 AM PST this morning for Central
     Panhandle Mountains-Northern Panhandle.

WA...Winter Weather Advisory until 10 AM PST this morning for
     Northeast Mountains.

&&

$$





000
FXUS66 KOTX 261154
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
354 AM PST WED NOV 26 2014

.SYNOPSIS...
Mild and breezy weather is expected today and Thanksgiving. By
late this morning, snow levels should rise above the mountain
passes. Motorists with plans to travel over the mountain passes
should experience good conditions this afternoon through Friday
afternoon. The arrival of a cold front Friday night into Saturday
will bring winter driving conditions to the mountain passes and
much cooler weather for the weekend.

&&

.DISCUSSION...

Today: The axis of the heaviest precipitation will continue to
migrate northward today as the jet stream is shunted Alberta and
Montana. Forecasting snow levels in the northern Cascades,
northeast Washington and far north Idaho over the last 24 hour has
been brutal. There has been a tremendously tight gradient between
snow levels of 6000 feet in places like Stevens Pass and the
valley floor in the Methow Valley. Fortunately this morning,
precipitation amounts will not be as heavy as they were yesterday
afternoon and evening. An additional 1 to 3 inches of snow
accumulation is expected this morning over the Pasayten Wilderness
to Sherman Pass to the mountains near Sandpoint. Another inch or
two of accumulation will also be possible early this morning over
Lookout Pass before snow transitions to rain shortly after
sunrise. Winter Weather Advisories will remain in effect through
10 AM for Lookout Pass and the northern portions of Stevens, Pend
Oreille, Bonner and Boundary counties.

The temperature forecast has been lowered along the East Slopes of
the Cascades, Waterville Plateau into the Moses Lake area. Thick
low clouds and fog will likely linger for a good portion of the
day. For the Palouse, West Plains and Ritzville areas, south winds
of 10 to 15 mph should develop by late morning providing mixing to
warm temperatures into the 40s and 50s.

Tonight into Thanksgiving: Snow levels will be at or above 6000
feet for Idaho and Washington tonight into Thanksgiving. Mountain
passes will experience periods of rain during this busy holiday
travel period, but the roads should be in relatively good shape.
Thanksgiving has the potential to be one of the warmest days of
the month. Despite mostly cloudy conditions, breezy southwest
winds will provide the mixing needed this time of year to push
temperatures into the 50s over much of the region. /GKoch

Friday through Sunday night...The region will start out under a
relatively warm and wet pattern Friday then transition to a much
colder but drier regime over the weekend. Westerly flow aloft will
continue to direct a moisture laden fetch across the region
Friday. The areas most favored for precipitation will be the
Cascade crest and the rising terrain north and east of the
Columbia Basin. The entire eastern half of the forecast area will
likely see a decent amount of precip as a surface low tracks south
from southeast British Columbia into central Idaho by Saturday.
Right now models are generally tracking it through the Idaho
panhandle but the precise track will determine how far west into
the basin the precip will extend. QPF could easily top an inch or
two for north Idaho as the low slowly sinks south. Snow levels
will start out quite high, ranging from 5k to 7k ft. Only the
highest peaks will see snow on Friday.

An arctic front will drop south across the forecast area Friday night
and Saturday, bringing in much drier and colder air, chasing
precip to the southeast zones by Saturday evening. Plunging snow
levels will allow accumulating snow for the southeast valleys with
possible winter highlight criteria being achieved, particularly
for the Camas Prairie on Saturday. Temperatures will plummet
Friday night with single digits for the typical cold spots in the
northern valleys. Most locations will see a 20 to 30 degree drop
overnight with only the southernmost valleys escaping freezing
temps. As the low drops south, the building arctic high over BC
will strengthen the surface pressure gradient between them. Winds
will increase down the north-south valleys and be funneled down
the Purcell trench and into the west Plains and basin. Expect wind
chill temperatures below zero in the Okanogan valley where the
strongest winds and very cold temps will prevail.

Cold conditions will continue Saturday night and Sunday with much
of the forecast area remaining dry. The exception will be the
southernmost counties where the surface front will stall. Surface
winds will diminish but remain northerly, reinforcing the cold air
in the valleys. Southwest flow ahead of the next Pacific trough
will result in strong warm air advection in the mid levels for
Sunday night into Monday. This layer of warm air overrunning the
resident cold air at the surface could bring mixed precipitation
to the Columbia Basin, Wenatchee Valley, L-C valley and possibly
as far north as the Spokane area. Temperature profiles for the
northern valleys appear to be cold enough to support all snow.
/Kelch

Monday through Wednesday: An active weather pattern is expected to
continue through this period. The GFS has been more consistent
with pushing warm moist air mass form the Southwest into the
region compared with the ECMWF which is depicting a dry Northwest
flow. This set up is expected to bring widespread precip to the
region. Snow for most locations in the Inland Northwest excluding
the rain for the Palouse and Camas Prairie areas through Tuesday
morning. A small ridge is expected to begin to build in the region
on Tuesday and bring a decrease in the precip Columbia Basin and
continues snow to the Cascades, Idaho Panhandle, and Canadian
Border regions. Temperatures are expected to range from upper 20s
for highs and low teens for lows. /JDC

&&

.AVIATION...
12Z TAFS: A 24 hour rain event over much of the Inland Northwest
has left a soup of low stratus and fog. Deep surface low pressure
approaching Vancouver Island today will produce increasing
southwest winds over southeast Washington which should bring some
improvement to ceilings. Fog and stratus should lift at
Lewiston and Pullman this morning. Low level wind shear has been
included at Pullman prior to 17z. Nearby Alpowa summit is gusting
to 40 mph and NAM forecast sounding show strong winds at 2000 feet
off the deck. Cold air damming along the East Slopes of the
Cascades into the Moses Lake area could make ceiling and
visibility improvements very slow to evolve. The 12z TAFS show a
gradual lifting of the cloud deck, but this may be optimistic
looking at the dewpoints over the southern Columbia Basin which
will be advected into the cold stable air trapped along the East
Slopes. /GKoch


&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        45  42  50  40  45  26 /  80  30  30  20  80  60
Coeur d`Alene  44  41  48  40  44  27 /  90  30  30  20  90  70
Pullman        54  44  53  42  48  31 /  30  30  30  20  80  80
Lewiston       56  47  58  45  52  37 /  10  10  10  20  70  80
Colville       38  38  46  38  42  20 /  90  60  50  40  80  10
Sandpoint      39  38  45  37  41  25 / 100  70  60  50  90  50
Kellogg        43  40  44  38  40  29 / 100  60  70  70  90  80
Moses Lake     46  44  55  40  50  25 /  10  10  10  10  30  20
Wenatchee      43  42  50  41  47  27 /  10  10  10  20  30  10
Omak           38  38  46  35  40  14 /  50  30  30  30  50  10

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Winter Weather Advisory until 10 AM PST this morning for Central
     Panhandle Mountains-Northern Panhandle.

WA...Winter Weather Advisory until 10 AM PST this morning for
     Northeast Mountains.

&&

$$





000
FXUS66 KOTX 261154
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
354 AM PST WED NOV 26 2014

.SYNOPSIS...
Mild and breezy weather is expected today and Thanksgiving. By
late this morning, snow levels should rise above the mountain
passes. Motorists with plans to travel over the mountain passes
should experience good conditions this afternoon through Friday
afternoon. The arrival of a cold front Friday night into Saturday
will bring winter driving conditions to the mountain passes and
much cooler weather for the weekend.

&&

.DISCUSSION...

Today: The axis of the heaviest precipitation will continue to
migrate northward today as the jet stream is shunted Alberta and
Montana. Forecasting snow levels in the northern Cascades,
northeast Washington and far north Idaho over the last 24 hour has
been brutal. There has been a tremendously tight gradient between
snow levels of 6000 feet in places like Stevens Pass and the
valley floor in the Methow Valley. Fortunately this morning,
precipitation amounts will not be as heavy as they were yesterday
afternoon and evening. An additional 1 to 3 inches of snow
accumulation is expected this morning over the Pasayten Wilderness
to Sherman Pass to the mountains near Sandpoint. Another inch or
two of accumulation will also be possible early this morning over
Lookout Pass before snow transitions to rain shortly after
sunrise. Winter Weather Advisories will remain in effect through
10 AM for Lookout Pass and the northern portions of Stevens, Pend
Oreille, Bonner and Boundary counties.

The temperature forecast has been lowered along the East Slopes of
the Cascades, Waterville Plateau into the Moses Lake area. Thick
low clouds and fog will likely linger for a good portion of the
day. For the Palouse, West Plains and Ritzville areas, south winds
of 10 to 15 mph should develop by late morning providing mixing to
warm temperatures into the 40s and 50s.

Tonight into Thanksgiving: Snow levels will be at or above 6000
feet for Idaho and Washington tonight into Thanksgiving. Mountain
passes will experience periods of rain during this busy holiday
travel period, but the roads should be in relatively good shape.
Thanksgiving has the potential to be one of the warmest days of
the month. Despite mostly cloudy conditions, breezy southwest
winds will provide the mixing needed this time of year to push
temperatures into the 50s over much of the region. /GKoch

Friday through Sunday night...The region will start out under a
relatively warm and wet pattern Friday then transition to a much
colder but drier regime over the weekend. Westerly flow aloft will
continue to direct a moisture laden fetch across the region
Friday. The areas most favored for precipitation will be the
Cascade crest and the rising terrain north and east of the
Columbia Basin. The entire eastern half of the forecast area will
likely see a decent amount of precip as a surface low tracks south
from southeast British Columbia into central Idaho by Saturday.
Right now models are generally tracking it through the Idaho
panhandle but the precise track will determine how far west into
the basin the precip will extend. QPF could easily top an inch or
two for north Idaho as the low slowly sinks south. Snow levels
will start out quite high, ranging from 5k to 7k ft. Only the
highest peaks will see snow on Friday.

An arctic front will drop south across the forecast area Friday night
and Saturday, bringing in much drier and colder air, chasing
precip to the southeast zones by Saturday evening. Plunging snow
levels will allow accumulating snow for the southeast valleys with
possible winter highlight criteria being achieved, particularly
for the Camas Prairie on Saturday. Temperatures will plummet
Friday night with single digits for the typical cold spots in the
northern valleys. Most locations will see a 20 to 30 degree drop
overnight with only the southernmost valleys escaping freezing
temps. As the low drops south, the building arctic high over BC
will strengthen the surface pressure gradient between them. Winds
will increase down the north-south valleys and be funneled down
the Purcell trench and into the west Plains and basin. Expect wind
chill temperatures below zero in the Okanogan valley where the
strongest winds and very cold temps will prevail.

Cold conditions will continue Saturday night and Sunday with much
of the forecast area remaining dry. The exception will be the
southernmost counties where the surface front will stall. Surface
winds will diminish but remain northerly, reinforcing the cold air
in the valleys. Southwest flow ahead of the next Pacific trough
will result in strong warm air advection in the mid levels for
Sunday night into Monday. This layer of warm air overrunning the
resident cold air at the surface could bring mixed precipitation
to the Columbia Basin, Wenatchee Valley, L-C valley and possibly
as far north as the Spokane area. Temperature profiles for the
northern valleys appear to be cold enough to support all snow.
/Kelch

Monday through Wednesday: An active weather pattern is expected to
continue through this period. The GFS has been more consistent
with pushing warm moist air mass form the Southwest into the
region compared with the ECMWF which is depicting a dry Northwest
flow. This set up is expected to bring widespread precip to the
region. Snow for most locations in the Inland Northwest excluding
the rain for the Palouse and Camas Prairie areas through Tuesday
morning. A small ridge is expected to begin to build in the region
on Tuesday and bring a decrease in the precip Columbia Basin and
continues snow to the Cascades, Idaho Panhandle, and Canadian
Border regions. Temperatures are expected to range from upper 20s
for highs and low teens for lows. /JDC

&&

.AVIATION...
12Z TAFS: A 24 hour rain event over much of the Inland Northwest
has left a soup of low stratus and fog. Deep surface low pressure
approaching Vancouver Island today will produce increasing
southwest winds over southeast Washington which should bring some
improvement to ceilings. Fog and stratus should lift at
Lewiston and Pullman this morning. Low level wind shear has been
included at Pullman prior to 17z. Nearby Alpowa summit is gusting
to 40 mph and NAM forecast sounding show strong winds at 2000 feet
off the deck. Cold air damming along the East Slopes of the
Cascades into the Moses Lake area could make ceiling and
visibility improvements very slow to evolve. The 12z TAFS show a
gradual lifting of the cloud deck, but this may be optimistic
looking at the dewpoints over the southern Columbia Basin which
will be advected into the cold stable air trapped along the East
Slopes. /GKoch


&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        45  42  50  40  45  26 /  80  30  30  20  80  60
Coeur d`Alene  44  41  48  40  44  27 /  90  30  30  20  90  70
Pullman        54  44  53  42  48  31 /  30  30  30  20  80  80
Lewiston       56  47  58  45  52  37 /  10  10  10  20  70  80
Colville       38  38  46  38  42  20 /  90  60  50  40  80  10
Sandpoint      39  38  45  37  41  25 / 100  70  60  50  90  50
Kellogg        43  40  44  38  40  29 / 100  60  70  70  90  80
Moses Lake     46  44  55  40  50  25 /  10  10  10  10  30  20
Wenatchee      43  42  50  41  47  27 /  10  10  10  20  30  10
Omak           38  38  46  35  40  14 /  50  30  30  30  50  10

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Winter Weather Advisory until 10 AM PST this morning for Central
     Panhandle Mountains-Northern Panhandle.

WA...Winter Weather Advisory until 10 AM PST this morning for
     Northeast Mountains.

&&

$$





000
FXUS66 KOTX 261154
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
354 AM PST WED NOV 26 2014

.SYNOPSIS...
Mild and breezy weather is expected today and Thanksgiving. By
late this morning, snow levels should rise above the mountain
passes. Motorists with plans to travel over the mountain passes
should experience good conditions this afternoon through Friday
afternoon. The arrival of a cold front Friday night into Saturday
will bring winter driving conditions to the mountain passes and
much cooler weather for the weekend.

&&

.DISCUSSION...

Today: The axis of the heaviest precipitation will continue to
migrate northward today as the jet stream is shunted Alberta and
Montana. Forecasting snow levels in the northern Cascades,
northeast Washington and far north Idaho over the last 24 hour has
been brutal. There has been a tremendously tight gradient between
snow levels of 6000 feet in places like Stevens Pass and the
valley floor in the Methow Valley. Fortunately this morning,
precipitation amounts will not be as heavy as they were yesterday
afternoon and evening. An additional 1 to 3 inches of snow
accumulation is expected this morning over the Pasayten Wilderness
to Sherman Pass to the mountains near Sandpoint. Another inch or
two of accumulation will also be possible early this morning over
Lookout Pass before snow transitions to rain shortly after
sunrise. Winter Weather Advisories will remain in effect through
10 AM for Lookout Pass and the northern portions of Stevens, Pend
Oreille, Bonner and Boundary counties.

The temperature forecast has been lowered along the East Slopes of
the Cascades, Waterville Plateau into the Moses Lake area. Thick
low clouds and fog will likely linger for a good portion of the
day. For the Palouse, West Plains and Ritzville areas, south winds
of 10 to 15 mph should develop by late morning providing mixing to
warm temperatures into the 40s and 50s.

Tonight into Thanksgiving: Snow levels will be at or above 6000
feet for Idaho and Washington tonight into Thanksgiving. Mountain
passes will experience periods of rain during this busy holiday
travel period, but the roads should be in relatively good shape.
Thanksgiving has the potential to be one of the warmest days of
the month. Despite mostly cloudy conditions, breezy southwest
winds will provide the mixing needed this time of year to push
temperatures into the 50s over much of the region. /GKoch

Friday through Sunday night...The region will start out under a
relatively warm and wet pattern Friday then transition to a much
colder but drier regime over the weekend. Westerly flow aloft will
continue to direct a moisture laden fetch across the region
Friday. The areas most favored for precipitation will be the
Cascade crest and the rising terrain north and east of the
Columbia Basin. The entire eastern half of the forecast area will
likely see a decent amount of precip as a surface low tracks south
from southeast British Columbia into central Idaho by Saturday.
Right now models are generally tracking it through the Idaho
panhandle but the precise track will determine how far west into
the basin the precip will extend. QPF could easily top an inch or
two for north Idaho as the low slowly sinks south. Snow levels
will start out quite high, ranging from 5k to 7k ft. Only the
highest peaks will see snow on Friday.

An arctic front will drop south across the forecast area Friday night
and Saturday, bringing in much drier and colder air, chasing
precip to the southeast zones by Saturday evening. Plunging snow
levels will allow accumulating snow for the southeast valleys with
possible winter highlight criteria being achieved, particularly
for the Camas Prairie on Saturday. Temperatures will plummet
Friday night with single digits for the typical cold spots in the
northern valleys. Most locations will see a 20 to 30 degree drop
overnight with only the southernmost valleys escaping freezing
temps. As the low drops south, the building arctic high over BC
will strengthen the surface pressure gradient between them. Winds
will increase down the north-south valleys and be funneled down
the Purcell trench and into the west Plains and basin. Expect wind
chill temperatures below zero in the Okanogan valley where the
strongest winds and very cold temps will prevail.

Cold conditions will continue Saturday night and Sunday with much
of the forecast area remaining dry. The exception will be the
southernmost counties where the surface front will stall. Surface
winds will diminish but remain northerly, reinforcing the cold air
in the valleys. Southwest flow ahead of the next Pacific trough
will result in strong warm air advection in the mid levels for
Sunday night into Monday. This layer of warm air overrunning the
resident cold air at the surface could bring mixed precipitation
to the Columbia Basin, Wenatchee Valley, L-C valley and possibly
as far north as the Spokane area. Temperature profiles for the
northern valleys appear to be cold enough to support all snow.
/Kelch

Monday through Wednesday: An active weather pattern is expected to
continue through this period. The GFS has been more consistent
with pushing warm moist air mass form the Southwest into the
region compared with the ECMWF which is depicting a dry Northwest
flow. This set up is expected to bring widespread precip to the
region. Snow for most locations in the Inland Northwest excluding
the rain for the Palouse and Camas Prairie areas through Tuesday
morning. A small ridge is expected to begin to build in the region
on Tuesday and bring a decrease in the precip Columbia Basin and
continues snow to the Cascades, Idaho Panhandle, and Canadian
Border regions. Temperatures are expected to range from upper 20s
for highs and low teens for lows. /JDC

&&

.AVIATION...
12Z TAFS: A 24 hour rain event over much of the Inland Northwest
has left a soup of low stratus and fog. Deep surface low pressure
approaching Vancouver Island today will produce increasing
southwest winds over southeast Washington which should bring some
improvement to ceilings. Fog and stratus should lift at
Lewiston and Pullman this morning. Low level wind shear has been
included at Pullman prior to 17z. Nearby Alpowa summit is gusting
to 40 mph and NAM forecast sounding show strong winds at 2000 feet
off the deck. Cold air damming along the East Slopes of the
Cascades into the Moses Lake area could make ceiling and
visibility improvements very slow to evolve. The 12z TAFS show a
gradual lifting of the cloud deck, but this may be optimistic
looking at the dewpoints over the southern Columbia Basin which
will be advected into the cold stable air trapped along the East
Slopes. /GKoch


&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        45  42  50  40  45  26 /  80  30  30  20  80  60
Coeur d`Alene  44  41  48  40  44  27 /  90  30  30  20  90  70
Pullman        54  44  53  42  48  31 /  30  30  30  20  80  80
Lewiston       56  47  58  45  52  37 /  10  10  10  20  70  80
Colville       38  38  46  38  42  20 /  90  60  50  40  80  10
Sandpoint      39  38  45  37  41  25 / 100  70  60  50  90  50
Kellogg        43  40  44  38  40  29 / 100  60  70  70  90  80
Moses Lake     46  44  55  40  50  25 /  10  10  10  10  30  20
Wenatchee      43  42  50  41  47  27 /  10  10  10  20  30  10
Omak           38  38  46  35  40  14 /  50  30  30  30  50  10

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Winter Weather Advisory until 10 AM PST this morning for Central
     Panhandle Mountains-Northern Panhandle.

WA...Winter Weather Advisory until 10 AM PST this morning for
     Northeast Mountains.

&&

$$





000
FXUS66 KPQR 261120
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
320 AM PST WED NOV 26 2014

.SYNOPSIS...A WARM FRONTAL BOUNDARY HAS MOSTLY LIFTED NORTH OF OUR
FORECAST AREA EARLY THIS MORNING...WITH JUST A LITTLE LIGHT
PRECIPITATION BRUSHING SOUTHWEST WASHINGTON...AND MILD AND DRY
WEATHER FOR THE REST OF THE AREA EXCEPT SOME LOCAL MORNING FOG. THE
ASSOCIATED COLD FRONT WILL REACH THE COAST AND START TO MOVE ONSHORE
TONIGHT...SPREADING ACROSS ALL OF THE AREA ON THANKSGIVING. LOOK FOR
RAIN AND COASTAL WIND. A SECONDARY COLDER COLD FRONT WILL DROP SOUTH
ACROSS SOUTHWEST WASHINGTON AND NORTHWEST OREGON FOR MORE RAIN ON
FRIDAY. MUCH COOLER AIR ASSOCIATED WITH THE NORTHERN BRANCH OF THE
JET STREAM IS FORECAST TO SPREAD OVER THE AREA THIS WEEKEND...FOR
ANOTHER ROUND OF EAST WIND IN THE COLUMBIA RIVER GORGE. SNOW LEVELS
WILL LOWER DRAMATICALLY THIS WEEKEND...BUT SLOWLY RISE EARLY NEXT
WEEK.
&&

.SHORT TERM...TODAY THROUGH FRIDAY...THE NATIONAL WEATHER SERVICE
DOPPLER RADAR IS RATHER QUIET EARLY THIS MORNING...WITH JUST SOME
RESIDUAL LIGHT PRECIPITATION OVER PARTS OF SOUTHWEST WASHINGTON. THE
MAIN WARM FRONT HAS LIFTED WELL NORTH OF THE AREA...LEAVING SOUTHWEST
WASHINGTON AND NORTHWEST OREGON IN THE VERY MILD WARM SECTOR. MOST OF
THE AREA WILL BE DRY TODAY AND AGAIN QUITE MILD... AND A FEW RECORDS
MAINLY IN THE NORTH WILL BE IN REACH AGAIN TODAY. WE MAY ALSO SEE
LOCAL FOG THIS MORNING AS DEWPOINTS ARE MOSTLY IN THE LOWER 50S.

THE ASSOCIATED COLD FRONT APPROACHING 130W EARLY THIS MORNING WILL
REACH THE COAST AND BEGIN SPREADING ONSHORE TONIGHT FOR MORE RAIN AND
SOME BRISK COASTAL WINDS...BUT LIKELY STAYING BELOW HIGH WIND
CRITERIA. THE FRONT WILL CONTINUE MOVING THROUGH THE FORECAST AREA ON
THANKSGIVING FOR MORE RAIN AND LOCALLY BREEZY CONDITIONS. SNOW LEVELS
WILL REMAIN QUITE HIGH IN THE CASCADES.

THE FRONTAL BOUNDARY WILL STALL OVER THE AREA THURSDAY NIGHT BENEATH
CONFLUENT FLOW ALOFT AS THE SOUTHERN BRANCH OF THE JET MERGES WITH AN
INCREASING NORTHERN BRANCH OF THE JET. THIS WILL KEEP SOME RAIN GOING
OVER MUCH OF THE AREA THURSDAY NIGHT.

A SECONDARY COLDER COLD FRONT WILL BEGIN SAGGING INTO OUR AREA FROM
THE NORTH ON FRIDAY...MERGING WITH THE STALLED SOUTHERN COLD
FRONT...AND KEEPING THE RAIN GOING...PERHAPS A LITTLE HEAVIER THAN ON
PREVIOUS DAYS. SNOW LEVELS IN THE SOUTH WASHINGTON CASCADES MAY BEGIN
TO FALL LATE IN THE DAY AS THIS SECONDARY COLD FRONT MOVES SOUTH BUT
SNOW LEVELS WILL GENERALLY STAY ABOVE THE PASS LEVELS THROUGH FRIDAY.
TOLLESON

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
FRIDAY NIGHT THROUGH TUESDAY...COMPLICATED PATTERN EVOLVES FRIDAY
NIGHT AND SAT WITH THE COLDER AIR CONTINUING TO SLIDE S THROUGH WA
AND INTO NRN OREGON. 12Z GFS MORE IN LINE WITH THE PREVIOUS COUPLE OF
ECMWF RUNS...DEPICTING A COLD AIR WEDGE IN THE CENTRAL COLUMBIA GORGE
BY 00Z SUN. LOOK FOR THE EAST WIND TO RETURN AS WELL...BEGINNING SAT
MORNING AND CONTINUING THROUGH THE WEEKEND. BY 00Z SUN THE GFS HAS -8
TO -10C 850 MB AIR IN THE CENTRAL COLUMBIA GORGE...WHILE THE ECMWF IS
JUST A TOUCH WARMER. FORTUNATELY...THE DRIER NLY FLOW WILL SHUNT
PRECIP FURTHER TO THE S. A CLOSED LOW WELL OF THE NRN CA COAST SAT
STARTS TO DRIFT NE SAT NIGHT AND SUN. THERE IS THE POTENTIAL FOR A
DEFORMATION BAND OVER NRN CA TO DRIFT NWD LATE SUN INTO MON. THIS
COULD BE PROBLEMATIC AS THE MOISTURE OVERRUNS THE COLD
AIR....ESPECIALLY FOR THE COLUMBIA GORGE AND UPPER HOOD RIVER VALLEY.
WEISHAAR
&&

.AVIATION...LIFR TO IFR CONDITIONS ON THE COAST SHOULD IMPROVE LATER
THIS MORNING AS PRESSURE GRADIENTS TURN SLIGHTLY MORE OFFSHORE.
INCREASING WINDS AND A NOSE OF DRIER AIR ALOFT MAY ALLOW CONDITIONS
TO EVEN TEMPORARILY IMPROVE TO VFR LATE THIS AFTERNOON AND EVENING
BEFORE CONDITIONS DETERIORATE AS A COLD FRONT...LOW CLOUDS AND RAIN
IMPACT THE COAST TOWARDS 12Z THURSDAY. FURTHER INLAND...MOST
LOCATIONS SHOULD REMAIN IN THE WARM SECTOR TODAY...WHICH SHOULD
PRODUCE VFR CONDITIONS THIS AFTERNOON THROUGH 12Z THURSDAY. IN THE
MEANTIME...A STRATUS DECK NEAR 5KFT IS CURRENTLY RESIDING ACROSS THE
WILLAMETTE VALLEY. MODELS SUGGEST IT WILL BEGIN TO CLEAR FROM
SOUTHWEST TO NORTHEAST THROUGH 18Z WEDNESDAY. GIVEN LOW DEWPOINT
DEPRESSIONS AND LITTLE WIND EARLY THIS MORNING...ANY LOCATIONS THAT
CLEAR WILL LIKELY DETERIORATE RAPIDLY. THIS APPEARS MOST LIKELY AT
KEUG AND KSLE...BUT THESE LOWER FLIGHT CONDITIONS COULD SNEAK INTO
THE PORTLAND METRO TOWARDS 15Z WEDNESDAY.

KPDX AND APPROACHES...VFR CONDITIONS EARLY THIS MORNING MAY GIVE WAY
TO MVFR OR LOWER CONDITIONS TOWARDS 15Z WEDNESDAY...BUT CONFIDENCE IS
DETERIORATING THESE LOWER FLIGHT CONDITIONS WILL MATERIALIZE.
REGARDLESS...VFR CONDITIONS SHOULD BE THE DOMINANT PLAYER THIS
AFTERNOON THROUGH 12Z THURSDAY. /NEUMAN
&&

.MARINE...AN INCOMING FRONTAL STORM SYSTEM WILL CAUSE WINDS TO
INCREASE TODAY. EXPECT PRIMARILY SMALL CRAFT ADVISORY LEVEL WIND
GUSTS TO 30 KT. HOWEVER...A WEAK COASTAL JET WILL LIKELY ENHANCE WIND
SPEEDS WITHIN 20 NM OF THE COAST BEGINNING LATE THIS AFTERNOON AND
LASTING THROUGH MUCH OF THE NIGHT. THIS SHOULD ALLOW GALE FORCE WIND
GUSTS OF 35 KT TO SURFACE ACROSS THE WATERS. THE HIGHEST WINDS APPEAR
ON TRACK FOR THE 7 PM WEDNESDAY TO 1 AM THURSDAY TIME FRAME. DUE TO
INHERENT UNCERTAINTY IN THESE SITUATIONS WILL KEEP THE TIMING OF THE
GALE WARNING AS IS.

PRESSURE GRADIENTS WILL REMAIN ELEVATED BEHIND THE FRONTAL STORM
SYSTEM SO EXPECT PERIODS OF SMALL CRAFT ADVISORY LEVEL WIND GUSTS OF
25 TO 30 KT THURSDAY AND THURSDAY NIGHT. A COUPLE WEAK LOW PRESSURES
TO OUR WEST MAY KEEP GUSTY WINDS AND HAZARDOUS SMALL CRAFT SEAS IN
THE LOWER TEENS GOING THROUGH MUCH OF FRIDAY. HOWEVER...A FRONT
SLIDING NORTH TO SOUTH ACROSS THE WATERS SHOULD ALLOW WINDS AND SEAS
TO RELAX FRIDAY OR SATURDAY...WITH THE EXACT TIMING OF WHEN THE FRONT
WILL MOVE ACROSS THE WATERS SOMEWHAT UNCERTAIN. NONETHELESS... WINDS
SHOULD TURN MORE OFFSHORE OVER THE WEEKEND...WITH GUSTY WINDS LIKELY
DEVELOPING NEAR COASTAL GAPS SUCH AS THE MOUTH OF THE COLUMBIA RIVER
AND NEAR TILLAMOOK. /NEUMAN
&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS FROM 4 AM EARLY THIS MORNING
     TO 4 PM PST THIS AFTERNOON FOR COASTAL WATERS FROM CAPE
     SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     GALE WARNING FROM 4 PM THIS AFTERNOON TO 4 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 5 AM TO
     9 AM PST THIS MORNING.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 4 PM
     THIS AFTERNOON TO 10 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 261120
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
320 AM PST WED NOV 26 2014

.SYNOPSIS...A WARM FRONTAL BOUNDARY HAS MOSTLY LIFTED NORTH OF OUR
FORECAST AREA EARLY THIS MORNING...WITH JUST A LITTLE LIGHT
PRECIPITATION BRUSHING SOUTHWEST WASHINGTON...AND MILD AND DRY
WEATHER FOR THE REST OF THE AREA EXCEPT SOME LOCAL MORNING FOG. THE
ASSOCIATED COLD FRONT WILL REACH THE COAST AND START TO MOVE ONSHORE
TONIGHT...SPREADING ACROSS ALL OF THE AREA ON THANKSGIVING. LOOK FOR
RAIN AND COASTAL WIND. A SECONDARY COLDER COLD FRONT WILL DROP SOUTH
ACROSS SOUTHWEST WASHINGTON AND NORTHWEST OREGON FOR MORE RAIN ON
FRIDAY. MUCH COOLER AIR ASSOCIATED WITH THE NORTHERN BRANCH OF THE
JET STREAM IS FORECAST TO SPREAD OVER THE AREA THIS WEEKEND...FOR
ANOTHER ROUND OF EAST WIND IN THE COLUMBIA RIVER GORGE. SNOW LEVELS
WILL LOWER DRAMATICALLY THIS WEEKEND...BUT SLOWLY RISE EARLY NEXT
WEEK.
&&

.SHORT TERM...TODAY THROUGH FRIDAY...THE NATIONAL WEATHER SERVICE
DOPPLER RADAR IS RATHER QUIET EARLY THIS MORNING...WITH JUST SOME
RESIDUAL LIGHT PRECIPITATION OVER PARTS OF SOUTHWEST WASHINGTON. THE
MAIN WARM FRONT HAS LIFTED WELL NORTH OF THE AREA...LEAVING SOUTHWEST
WASHINGTON AND NORTHWEST OREGON IN THE VERY MILD WARM SECTOR. MOST OF
THE AREA WILL BE DRY TODAY AND AGAIN QUITE MILD... AND A FEW RECORDS
MAINLY IN THE NORTH WILL BE IN REACH AGAIN TODAY. WE MAY ALSO SEE
LOCAL FOG THIS MORNING AS DEWPOINTS ARE MOSTLY IN THE LOWER 50S.

THE ASSOCIATED COLD FRONT APPROACHING 130W EARLY THIS MORNING WILL
REACH THE COAST AND BEGIN SPREADING ONSHORE TONIGHT FOR MORE RAIN AND
SOME BRISK COASTAL WINDS...BUT LIKELY STAYING BELOW HIGH WIND
CRITERIA. THE FRONT WILL CONTINUE MOVING THROUGH THE FORECAST AREA ON
THANKSGIVING FOR MORE RAIN AND LOCALLY BREEZY CONDITIONS. SNOW LEVELS
WILL REMAIN QUITE HIGH IN THE CASCADES.

THE FRONTAL BOUNDARY WILL STALL OVER THE AREA THURSDAY NIGHT BENEATH
CONFLUENT FLOW ALOFT AS THE SOUTHERN BRANCH OF THE JET MERGES WITH AN
INCREASING NORTHERN BRANCH OF THE JET. THIS WILL KEEP SOME RAIN GOING
OVER MUCH OF THE AREA THURSDAY NIGHT.

A SECONDARY COLDER COLD FRONT WILL BEGIN SAGGING INTO OUR AREA FROM
THE NORTH ON FRIDAY...MERGING WITH THE STALLED SOUTHERN COLD
FRONT...AND KEEPING THE RAIN GOING...PERHAPS A LITTLE HEAVIER THAN ON
PREVIOUS DAYS. SNOW LEVELS IN THE SOUTH WASHINGTON CASCADES MAY BEGIN
TO FALL LATE IN THE DAY AS THIS SECONDARY COLD FRONT MOVES SOUTH BUT
SNOW LEVELS WILL GENERALLY STAY ABOVE THE PASS LEVELS THROUGH FRIDAY.
TOLLESON

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
FRIDAY NIGHT THROUGH TUESDAY...COMPLICATED PATTERN EVOLVES FRIDAY
NIGHT AND SAT WITH THE COLDER AIR CONTINUING TO SLIDE S THROUGH WA
AND INTO NRN OREGON. 12Z GFS MORE IN LINE WITH THE PREVIOUS COUPLE OF
ECMWF RUNS...DEPICTING A COLD AIR WEDGE IN THE CENTRAL COLUMBIA GORGE
BY 00Z SUN. LOOK FOR THE EAST WIND TO RETURN AS WELL...BEGINNING SAT
MORNING AND CONTINUING THROUGH THE WEEKEND. BY 00Z SUN THE GFS HAS -8
TO -10C 850 MB AIR IN THE CENTRAL COLUMBIA GORGE...WHILE THE ECMWF IS
JUST A TOUCH WARMER. FORTUNATELY...THE DRIER NLY FLOW WILL SHUNT
PRECIP FURTHER TO THE S. A CLOSED LOW WELL OF THE NRN CA COAST SAT
STARTS TO DRIFT NE SAT NIGHT AND SUN. THERE IS THE POTENTIAL FOR A
DEFORMATION BAND OVER NRN CA TO DRIFT NWD LATE SUN INTO MON. THIS
COULD BE PROBLEMATIC AS THE MOISTURE OVERRUNS THE COLD
AIR....ESPECIALLY FOR THE COLUMBIA GORGE AND UPPER HOOD RIVER VALLEY.
WEISHAAR
&&

.AVIATION...LIFR TO IFR CONDITIONS ON THE COAST SHOULD IMPROVE LATER
THIS MORNING AS PRESSURE GRADIENTS TURN SLIGHTLY MORE OFFSHORE.
INCREASING WINDS AND A NOSE OF DRIER AIR ALOFT MAY ALLOW CONDITIONS
TO EVEN TEMPORARILY IMPROVE TO VFR LATE THIS AFTERNOON AND EVENING
BEFORE CONDITIONS DETERIORATE AS A COLD FRONT...LOW CLOUDS AND RAIN
IMPACT THE COAST TOWARDS 12Z THURSDAY. FURTHER INLAND...MOST
LOCATIONS SHOULD REMAIN IN THE WARM SECTOR TODAY...WHICH SHOULD
PRODUCE VFR CONDITIONS THIS AFTERNOON THROUGH 12Z THURSDAY. IN THE
MEANTIME...A STRATUS DECK NEAR 5KFT IS CURRENTLY RESIDING ACROSS THE
WILLAMETTE VALLEY. MODELS SUGGEST IT WILL BEGIN TO CLEAR FROM
SOUTHWEST TO NORTHEAST THROUGH 18Z WEDNESDAY. GIVEN LOW DEWPOINT
DEPRESSIONS AND LITTLE WIND EARLY THIS MORNING...ANY LOCATIONS THAT
CLEAR WILL LIKELY DETERIORATE RAPIDLY. THIS APPEARS MOST LIKELY AT
KEUG AND KSLE...BUT THESE LOWER FLIGHT CONDITIONS COULD SNEAK INTO
THE PORTLAND METRO TOWARDS 15Z WEDNESDAY.

KPDX AND APPROACHES...VFR CONDITIONS EARLY THIS MORNING MAY GIVE WAY
TO MVFR OR LOWER CONDITIONS TOWARDS 15Z WEDNESDAY...BUT CONFIDENCE IS
DETERIORATING THESE LOWER FLIGHT CONDITIONS WILL MATERIALIZE.
REGARDLESS...VFR CONDITIONS SHOULD BE THE DOMINANT PLAYER THIS
AFTERNOON THROUGH 12Z THURSDAY. /NEUMAN
&&

.MARINE...AN INCOMING FRONTAL STORM SYSTEM WILL CAUSE WINDS TO
INCREASE TODAY. EXPECT PRIMARILY SMALL CRAFT ADVISORY LEVEL WIND
GUSTS TO 30 KT. HOWEVER...A WEAK COASTAL JET WILL LIKELY ENHANCE WIND
SPEEDS WITHIN 20 NM OF THE COAST BEGINNING LATE THIS AFTERNOON AND
LASTING THROUGH MUCH OF THE NIGHT. THIS SHOULD ALLOW GALE FORCE WIND
GUSTS OF 35 KT TO SURFACE ACROSS THE WATERS. THE HIGHEST WINDS APPEAR
ON TRACK FOR THE 7 PM WEDNESDAY TO 1 AM THURSDAY TIME FRAME. DUE TO
INHERENT UNCERTAINTY IN THESE SITUATIONS WILL KEEP THE TIMING OF THE
GALE WARNING AS IS.

PRESSURE GRADIENTS WILL REMAIN ELEVATED BEHIND THE FRONTAL STORM
SYSTEM SO EXPECT PERIODS OF SMALL CRAFT ADVISORY LEVEL WIND GUSTS OF
25 TO 30 KT THURSDAY AND THURSDAY NIGHT. A COUPLE WEAK LOW PRESSURES
TO OUR WEST MAY KEEP GUSTY WINDS AND HAZARDOUS SMALL CRAFT SEAS IN
THE LOWER TEENS GOING THROUGH MUCH OF FRIDAY. HOWEVER...A FRONT
SLIDING NORTH TO SOUTH ACROSS THE WATERS SHOULD ALLOW WINDS AND SEAS
TO RELAX FRIDAY OR SATURDAY...WITH THE EXACT TIMING OF WHEN THE FRONT
WILL MOVE ACROSS THE WATERS SOMEWHAT UNCERTAIN. NONETHELESS... WINDS
SHOULD TURN MORE OFFSHORE OVER THE WEEKEND...WITH GUSTY WINDS LIKELY
DEVELOPING NEAR COASTAL GAPS SUCH AS THE MOUTH OF THE COLUMBIA RIVER
AND NEAR TILLAMOOK. /NEUMAN
&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS FROM 4 AM EARLY THIS MORNING
     TO 4 PM PST THIS AFTERNOON FOR COASTAL WATERS FROM CAPE
     SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     GALE WARNING FROM 4 PM THIS AFTERNOON TO 4 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 5 AM TO
     9 AM PST THIS MORNING.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 4 PM
     THIS AFTERNOON TO 10 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 KSEW 261104
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
330 AM PST WED NOV 26 2014

.SYNOPSIS...A WARM FRONT WILL REMAIN NEAR THE CANADIAN BORDER TODAY.
A COLD FRONT WILL MOVE ACROSS THE AREA TONIGHT FOR MORE RAIN
AND WINDY CONDITIONS. RAIN WILL CONTINUE ON THANKSGIVING DAY AS
ANOTHER COLD FRONT APPROACHES FROM THE NORTH THEN CROSSES THE AREA
ON FRIDAY. COOL DRY AND BREEZY WEATHER WILL DEVELOP BY FRIDAY
AFTERNOON AND CONTINUE THROUGH THE WEEKEND AS HIGH PRESSURE BUILDS
OVER BRITISH COLUMBIA.

&&

.SHORT TERM...WESTERN WASHINGTON IS IN THE WARM SECTOR AS A WARM
FRONT LIFTED NORTH THROUGH THE REGION OVERNIGHT. AS A RESULT...TEMPS
REMAINED MILD WITH READINGS MAINLY IN THE 50S THIS MORNING. THE WARM
FRONT IS OVER SOUTHERN B.C. NOW AND RAIN WILL MAINLY AFFECT THE
NORTHERN EDGE OF THE CWA TODAY...AND ALSO THE MOUNTAINS. RIVERS ARE
STILL RISING AND FLOOD WATCHES AND WARNING ARE IN EFFECT...SEE
HYDROLOGY DISCUSSION BELOW. TEMPS WILL REMAIN MILD THIS AFTERNOON
WITH HIGHS IN THE MID TO UPPER 50S.

RAIN WILL INCREASE IN COVERAGE TONIGHT THROUGH THURSDAY AS A COLD
FRONT MOVES INLAND. SE PRESSURE GRADIENTS WILL TIGHTEN AS THIS
SYSTEM APPROACHES AND MAY SEE WIND ADVISORY SPEEDS ALONG THE COAST
AND NORTH INTERIOR ZONES TONIGHT. THIS FRONT WILL BRING ANOTHER SHOT
OF HEAVY RAIN TO THE MOUNTAINS...LEADING TO MORE FLOOD CONCERNS.
SNOW LEVELS WILL REMAIN HIGH AT 6000 TO 7000 FT. EXPECT RAIN AT
TIMES IN THE LOWLANDS THROUGHOUT THANKSGIVING DAY.

ANOTHER COLD FRONT WILL CROSS FROM NW TO SE THROUGH WESTERN WA ON
FRIDAY...BRINGING MORE RAIN AND WINDY CONDITIONS. THIS FRONT SHOULD
EXIT SOUTH FRI AFTERNOON. MODELS ARE SHOWING GUSTY FRASER RIVER
OUTFLOW WINDS FRI AFTERNOON OR EVENING AS STRONG HIGH PRES OVER
INTERIOR B.C. SAGS SOUTH. THIS COOL AND DRY AIR WILL FILTER SOUTH
INTO WESTERN WA FRI NIGHT. THE AIR MASS WILL BE COOL AND UNSTABLE AS
A DEEP UPPER TROUGH ALSO CLIPS WESTERN WA DURING THIS PERIOD. THERE
IS A CHANCE OF SNOW IN THE INTERIOR FRI NIGHT INTO SAT MORNING AS
THIS TROUGH CROSSES THE REGION. MODELS ARE NOW TRYING TO FORM A
CONVERGENCE ZONE WHERE COOL NORTHERLY FRASER OUTFLOW MEETS THE MOIST
S/SW ONSHORE FLOW. COULD SEE RAIN/SNOW IN THE CONVERGENCE ZONE. BUT
THIS COULD OCCUR ANYWHERE IN THE INTERIOR. TOUGH TO PIN THIS DOWN
EXACTLY BUT DEFINITELY NEED TO KEEP A CLOSE EYE IF THIS SCENARIO
PANS OUT. MODELS DO SHOW THE TROUGH EXITING SAT MORNING WITH DRY
WEATHER EXPECTED. 33

.LONG TERM...LONG RANGE MODELS SHOW A COOL AND DRY AIR MASS OVER
WESTERN WA ON SUNDAY. HIGH PRES OVER INTERIOR B.C. WILL MAINTAIN
EASTERLY FLOW THROUGH THE PASSES. LOWS SUNDAY MORNING WILL BE DOWN
TO THE 20S TO LOWER 30S ONCE AGAIN. HIGHS ARE ALSO BELOW NORMAL ON
SUNDAY WITH UPPER 30S TO LOWER 40S EXPECTED. MODELS WERE SHOWING
SOME MOISTURE SPREADING NORTH SUN NIGHT OR MON BUT THEY ARE NOW
BACKING OFF ON THIS IDEA. SO THE FORECAST IS NOW LOOKING DRIER OVER
THIS PERIOD AS WELL. THE FORECAST IS ALSO LOOKING DRIER THROUGH
MIDWEEK NOW AS THE EURO TRIES TO BUILD A RIDGE OVER THE PAC NW. 33

&&

.HYDROLOGY...RAIN RATES HAVE DECREASED THROUGHOUT THE CASCADES
OVERNIGHT...WHILE THE WARM FRONT HAS CONTINUED MOVING SLOWLY
NORTHWARD. RAINFALL AMOUNTS OF 0.5 TO 1.2 INCHES DURING THE PAST 6
HOURS WERE STILL COMMON FROM THE STILLAGUAMISH BASIN NORTHWARD...BUT
RATES THERE SHOULD DECREASE THIS MORNING. THE STILLAGUAMISH REACHED
FLOOD STAGE EARLY THIS MORNING...AND FLOODING IS STILL A SHORT TERM
CONCERN FOR THE NOOKSACK RIVER.

THERE HAS NOT BEEN MUCH RAIN OVERNIGHT SOUTH OF THE STILLAGUAMISH
BASIN -- GENERALLY 0.5 INCH OR LESS. THE THREE FORKS OF THE
SNOQUALMIE RIVER APPEAR TO HAVE CRESTED...SO THE SNOQUALMIE AT THE
FALLS SHOULD CREST EARLY THIS MORNING WITH THE CREST MOVING
DOWNSTREAM THROUGH CARNATION LATE THIS AFTERNOON. FLOODING ON THE
SNOQUALMIE WILL CONTINUE THROUGH TONIGHT. THE SKYKOMISH RIVER HAS
BEEN RUNNING WITHIN A FOOT OF FLOOD STAGE...BUT IT WILL PROBABLY
BEGIN FALLING SOON. THE SNOHOMISH...WHICH IS FORMED BY THE
CONFLUENCE OF THE SKYKOMISH AND SNOQUALMIE RIVERS...COULD HAVE SOME
FLOODING LATER TODAY.

THE RIVERS THAT FLOW OFF MOUNT RAINIER ARE RECEDING. THE FLOODING
HAS ENDED FOR THE CARBON AND NISQUALLY RIVERS...BUT FLOODING WILL
CONTINUE FOR THE COWLITZ AND REACH OF THE PUYALLUP NEAR ORTING.

NEXT WE TURN OUR ATTENTION TO THE FRONTAL SYSTEM THAT WILL BRING
SIGNIFICANT RAINFALL TONIGHT THROUGH THURSDAY NIGHT. WE ARE
EXPECTING STORM TOTALS IN THE MOUNTAINS OF 3 TO 5 INCHES DURING THE
36 HOURS FROM 4 PM TODAY THROUGH 4 AM FRIDAY. THE OLYMPICS AND NORTH
CASCADES WILL RECEIVE THE HEAVIEST RAINFALL...BUT LOCALLY UP TO 5
INCHES OVER MOUNT RAINIER AND SKYKOMISH-SNOQUALMIE-TOLT-SNOHOMISH
BASIN IS POSSIBLE TOO. THE SNOW LEVEL WILL BE 5500 TO 7000 FT FOR
MOST OF THE EVENT...THEN FALL ON FRIDAY AS A COLD FRONT MOVES
THROUGH FROM THE NORTHWEST AND PRECIPITATION DECREASES.

A MAJOR FLOODING EPISODE IS UNLIKELY...BUT THE RAINFALL COULD
CERTAINLY RENEW FLOODING ON THE RIVERS THAT FLOODED OR ALMOST
FLOODED AND SOME OTHER RIVERS COULD REACH FLOOD STAGE AS WELL. A
FLOOD WATCH IS IN EFFECT THROUGH FRIDAY...WHICH INCLUDES ALL THE
COUNTIES WITH RIVERS FLOWING OFF THE WEST SLOPES OF THE CASCADES AND
MASON COUNTY FOR THE POSSIBILITY OF A FLOOD ON THE SKOKOMISH.

COLDER AND DRIER WEATHER IS LIKELY THIS WEEKEND...SO RIVERS SHOULD
RECEDE AND THE FLOOD THREAT WILL END FOR THE FORESEEABLE FUTURE.
MCDONNAL

&&

.AVIATION...THE WARM FRONT THAT BROUGHT ALL THE RAIN TO WESTERN
WASHINGTON THE PAST COUPLE DAYS HAS MOVED INTO BRITISH COLUMBIA.
HOWEVER A WARM MOIST AIR MASS REMAINS OVER WESTERN WASHINGTON WITH
WIDESPREAD LOW-END MVFR TO IFR CONDITIONS...INCLUDING SOME
VISIBILITIES BELOW 3SM IN FOG AND LIGHT PRECIPITATION.

IMPROVEMENT TODAY WILL BE GRADUAL AND MAINLY LIMITED TO THE PUGET
SOUND REGION AND SOUTHWEST INTERIOR. ANOTHER VIGOROUS FRONTAL SYSTEM
WILL BRING MORE RAIN TO THE COAST LATE TODAY...SPREADING INTO THE
WESTERN WASHINGTON INTERIOR THIS EVENING. WHATEVER IMPROVEMENT
OCCURS TODAY IS LIKELY TO BE QUICKLY UNDONE AS A RESULT.

KSEA...SOUTH WIND MOSTLY 10-16 KT GUSTING 24 KT THROUGH TONIGHT...
EXCEPT THERE COULD BE A BRIEF LULL LATE THIS MORNING AND AFTERNOON.
THE GRADUAL IMPROVEMENT IN CEILINGS SHOULD CONTINUE TODAY...BUT
CONDITIONS WILL DETERIORATE TONIGHT AS THE NEXT FRONTAL SYSTEM
ARRIVES.   MCDONNAL

&&

.MARINE...A COLD FRONT WILL APPROACH THE WATERS TODAY AND MOVE
ONSHORE TONIGHT. SMALL CRAFT ADVISORY SOUTHERLY WINDS WILL BE COMMON
MOST WATERS TODAY...THEN GALES FOR SOME WATERS TONIGHT AS THE FRONT
MOVES THROUGH. MODERATE TO STRONG ONSHORE FLOW WILL PREVAIL BEHIND
THE FRONT ON THURSDAY.

ANOTHER COLD FRONT WILL MOVE THROUGH THE WATERS ON FRIDAY. THIS
FRONT WILL BE FOLLOWED BY STRONG FRASER OUTFLOW IN THE NORTHERN
INLAND WATERS AND MODERATE NORTHERLY WINDS OVER THE OTHER WATERS
LATER FRIDAY INTO SATURDAY. SCHNEIDER

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...FLOOD WATCHES AND WARNINGS IN EFFECT FOR PORTIONS OF
     WESTERN WASHINGTON.
PZ...SMALL CRAFT ADVISORY ALL WATERS.
    .SMALL CRAFT ADVISORY GRAYS HARBOR BAR FOR ROUGH BAR.
    .GALE WARNING COASTAL WATERS...ENTRANCES STRAIT OF JUAN DE
     FUCA...AND NORTHERN INLAND WATERS LATE THIS AFTERNOON AND
     TONIGHT.

&&

$$

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 261104
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
330 AM PST WED NOV 26 2014

.SYNOPSIS...A WARM FRONT WILL REMAIN NEAR THE CANADIAN BORDER TODAY.
A COLD FRONT WILL MOVE ACROSS THE AREA TONIGHT FOR MORE RAIN
AND WINDY CONDITIONS. RAIN WILL CONTINUE ON THANKSGIVING DAY AS
ANOTHER COLD FRONT APPROACHES FROM THE NORTH THEN CROSSES THE AREA
ON FRIDAY. COOL DRY AND BREEZY WEATHER WILL DEVELOP BY FRIDAY
AFTERNOON AND CONTINUE THROUGH THE WEEKEND AS HIGH PRESSURE BUILDS
OVER BRITISH COLUMBIA.

&&

.SHORT TERM...WESTERN WASHINGTON IS IN THE WARM SECTOR AS A WARM
FRONT LIFTED NORTH THROUGH THE REGION OVERNIGHT. AS A RESULT...TEMPS
REMAINED MILD WITH READINGS MAINLY IN THE 50S THIS MORNING. THE WARM
FRONT IS OVER SOUTHERN B.C. NOW AND RAIN WILL MAINLY AFFECT THE
NORTHERN EDGE OF THE CWA TODAY...AND ALSO THE MOUNTAINS. RIVERS ARE
STILL RISING AND FLOOD WATCHES AND WARNING ARE IN EFFECT...SEE
HYDROLOGY DISCUSSION BELOW. TEMPS WILL REMAIN MILD THIS AFTERNOON
WITH HIGHS IN THE MID TO UPPER 50S.

RAIN WILL INCREASE IN COVERAGE TONIGHT THROUGH THURSDAY AS A COLD
FRONT MOVES INLAND. SE PRESSURE GRADIENTS WILL TIGHTEN AS THIS
SYSTEM APPROACHES AND MAY SEE WIND ADVISORY SPEEDS ALONG THE COAST
AND NORTH INTERIOR ZONES TONIGHT. THIS FRONT WILL BRING ANOTHER SHOT
OF HEAVY RAIN TO THE MOUNTAINS...LEADING TO MORE FLOOD CONCERNS.
SNOW LEVELS WILL REMAIN HIGH AT 6000 TO 7000 FT. EXPECT RAIN AT
TIMES IN THE LOWLANDS THROUGHOUT THANKSGIVING DAY.

ANOTHER COLD FRONT WILL CROSS FROM NW TO SE THROUGH WESTERN WA ON
FRIDAY...BRINGING MORE RAIN AND WINDY CONDITIONS. THIS FRONT SHOULD
EXIT SOUTH FRI AFTERNOON. MODELS ARE SHOWING GUSTY FRASER RIVER
OUTFLOW WINDS FRI AFTERNOON OR EVENING AS STRONG HIGH PRES OVER
INTERIOR B.C. SAGS SOUTH. THIS COOL AND DRY AIR WILL FILTER SOUTH
INTO WESTERN WA FRI NIGHT. THE AIR MASS WILL BE COOL AND UNSTABLE AS
A DEEP UPPER TROUGH ALSO CLIPS WESTERN WA DURING THIS PERIOD. THERE
IS A CHANCE OF SNOW IN THE INTERIOR FRI NIGHT INTO SAT MORNING AS
THIS TROUGH CROSSES THE REGION. MODELS ARE NOW TRYING TO FORM A
CONVERGENCE ZONE WHERE COOL NORTHERLY FRASER OUTFLOW MEETS THE MOIST
S/SW ONSHORE FLOW. COULD SEE RAIN/SNOW IN THE CONVERGENCE ZONE. BUT
THIS COULD OCCUR ANYWHERE IN THE INTERIOR. TOUGH TO PIN THIS DOWN
EXACTLY BUT DEFINITELY NEED TO KEEP A CLOSE EYE IF THIS SCENARIO
PANS OUT. MODELS DO SHOW THE TROUGH EXITING SAT MORNING WITH DRY
WEATHER EXPECTED. 33

.LONG TERM...LONG RANGE MODELS SHOW A COOL AND DRY AIR MASS OVER
WESTERN WA ON SUNDAY. HIGH PRES OVER INTERIOR B.C. WILL MAINTAIN
EASTERLY FLOW THROUGH THE PASSES. LOWS SUNDAY MORNING WILL BE DOWN
TO THE 20S TO LOWER 30S ONCE AGAIN. HIGHS ARE ALSO BELOW NORMAL ON
SUNDAY WITH UPPER 30S TO LOWER 40S EXPECTED. MODELS WERE SHOWING
SOME MOISTURE SPREADING NORTH SUN NIGHT OR MON BUT THEY ARE NOW
BACKING OFF ON THIS IDEA. SO THE FORECAST IS NOW LOOKING DRIER OVER
THIS PERIOD AS WELL. THE FORECAST IS ALSO LOOKING DRIER THROUGH
MIDWEEK NOW AS THE EURO TRIES TO BUILD A RIDGE OVER THE PAC NW. 33

&&

.HYDROLOGY...RAIN RATES HAVE DECREASED THROUGHOUT THE CASCADES
OVERNIGHT...WHILE THE WARM FRONT HAS CONTINUED MOVING SLOWLY
NORTHWARD. RAINFALL AMOUNTS OF 0.5 TO 1.2 INCHES DURING THE PAST 6
HOURS WERE STILL COMMON FROM THE STILLAGUAMISH BASIN NORTHWARD...BUT
RATES THERE SHOULD DECREASE THIS MORNING. THE STILLAGUAMISH REACHED
FLOOD STAGE EARLY THIS MORNING...AND FLOODING IS STILL A SHORT TERM
CONCERN FOR THE NOOKSACK RIVER.

THERE HAS NOT BEEN MUCH RAIN OVERNIGHT SOUTH OF THE STILLAGUAMISH
BASIN -- GENERALLY 0.5 INCH OR LESS. THE THREE FORKS OF THE
SNOQUALMIE RIVER APPEAR TO HAVE CRESTED...SO THE SNOQUALMIE AT THE
FALLS SHOULD CREST EARLY THIS MORNING WITH THE CREST MOVING
DOWNSTREAM THROUGH CARNATION LATE THIS AFTERNOON. FLOODING ON THE
SNOQUALMIE WILL CONTINUE THROUGH TONIGHT. THE SKYKOMISH RIVER HAS
BEEN RUNNING WITHIN A FOOT OF FLOOD STAGE...BUT IT WILL PROBABLY
BEGIN FALLING SOON. THE SNOHOMISH...WHICH IS FORMED BY THE
CONFLUENCE OF THE SKYKOMISH AND SNOQUALMIE RIVERS...COULD HAVE SOME
FLOODING LATER TODAY.

THE RIVERS THAT FLOW OFF MOUNT RAINIER ARE RECEDING. THE FLOODING
HAS ENDED FOR THE CARBON AND NISQUALLY RIVERS...BUT FLOODING WILL
CONTINUE FOR THE COWLITZ AND REACH OF THE PUYALLUP NEAR ORTING.

NEXT WE TURN OUR ATTENTION TO THE FRONTAL SYSTEM THAT WILL BRING
SIGNIFICANT RAINFALL TONIGHT THROUGH THURSDAY NIGHT. WE ARE
EXPECTING STORM TOTALS IN THE MOUNTAINS OF 3 TO 5 INCHES DURING THE
36 HOURS FROM 4 PM TODAY THROUGH 4 AM FRIDAY. THE OLYMPICS AND NORTH
CASCADES WILL RECEIVE THE HEAVIEST RAINFALL...BUT LOCALLY UP TO 5
INCHES OVER MOUNT RAINIER AND SKYKOMISH-SNOQUALMIE-TOLT-SNOHOMISH
BASIN IS POSSIBLE TOO. THE SNOW LEVEL WILL BE 5500 TO 7000 FT FOR
MOST OF THE EVENT...THEN FALL ON FRIDAY AS A COLD FRONT MOVES
THROUGH FROM THE NORTHWEST AND PRECIPITATION DECREASES.

A MAJOR FLOODING EPISODE IS UNLIKELY...BUT THE RAINFALL COULD
CERTAINLY RENEW FLOODING ON THE RIVERS THAT FLOODED OR ALMOST
FLOODED AND SOME OTHER RIVERS COULD REACH FLOOD STAGE AS WELL. A
FLOOD WATCH IS IN EFFECT THROUGH FRIDAY...WHICH INCLUDES ALL THE
COUNTIES WITH RIVERS FLOWING OFF THE WEST SLOPES OF THE CASCADES AND
MASON COUNTY FOR THE POSSIBILITY OF A FLOOD ON THE SKOKOMISH.

COLDER AND DRIER WEATHER IS LIKELY THIS WEEKEND...SO RIVERS SHOULD
RECEDE AND THE FLOOD THREAT WILL END FOR THE FORESEEABLE FUTURE.
MCDONNAL

&&

.AVIATION...THE WARM FRONT THAT BROUGHT ALL THE RAIN TO WESTERN
WASHINGTON THE PAST COUPLE DAYS HAS MOVED INTO BRITISH COLUMBIA.
HOWEVER A WARM MOIST AIR MASS REMAINS OVER WESTERN WASHINGTON WITH
WIDESPREAD LOW-END MVFR TO IFR CONDITIONS...INCLUDING SOME
VISIBILITIES BELOW 3SM IN FOG AND LIGHT PRECIPITATION.

IMPROVEMENT TODAY WILL BE GRADUAL AND MAINLY LIMITED TO THE PUGET
SOUND REGION AND SOUTHWEST INTERIOR. ANOTHER VIGOROUS FRONTAL SYSTEM
WILL BRING MORE RAIN TO THE COAST LATE TODAY...SPREADING INTO THE
WESTERN WASHINGTON INTERIOR THIS EVENING. WHATEVER IMPROVEMENT
OCCURS TODAY IS LIKELY TO BE QUICKLY UNDONE AS A RESULT.

KSEA...SOUTH WIND MOSTLY 10-16 KT GUSTING 24 KT THROUGH TONIGHT...
EXCEPT THERE COULD BE A BRIEF LULL LATE THIS MORNING AND AFTERNOON.
THE GRADUAL IMPROVEMENT IN CEILINGS SHOULD CONTINUE TODAY...BUT
CONDITIONS WILL DETERIORATE TONIGHT AS THE NEXT FRONTAL SYSTEM
ARRIVES.   MCDONNAL

&&

.MARINE...A COLD FRONT WILL APPROACH THE WATERS TODAY AND MOVE
ONSHORE TONIGHT. SMALL CRAFT ADVISORY SOUTHERLY WINDS WILL BE COMMON
MOST WATERS TODAY...THEN GALES FOR SOME WATERS TONIGHT AS THE FRONT
MOVES THROUGH. MODERATE TO STRONG ONSHORE FLOW WILL PREVAIL BEHIND
THE FRONT ON THURSDAY.

ANOTHER COLD FRONT WILL MOVE THROUGH THE WATERS ON FRIDAY. THIS
FRONT WILL BE FOLLOWED BY STRONG FRASER OUTFLOW IN THE NORTHERN
INLAND WATERS AND MODERATE NORTHERLY WINDS OVER THE OTHER WATERS
LATER FRIDAY INTO SATURDAY. SCHNEIDER

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...FLOOD WATCHES AND WARNINGS IN EFFECT FOR PORTIONS OF
     WESTERN WASHINGTON.
PZ...SMALL CRAFT ADVISORY ALL WATERS.
    .SMALL CRAFT ADVISORY GRAYS HARBOR BAR FOR ROUGH BAR.
    .GALE WARNING COASTAL WATERS...ENTRANCES STRAIT OF JUAN DE
     FUCA...AND NORTHERN INLAND WATERS LATE THIS AFTERNOON AND
     TONIGHT.

&&

$$

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000
FXUS66 KSEW 261104
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
330 AM PST WED NOV 26 2014

.SYNOPSIS...A WARM FRONT WILL REMAIN NEAR THE CANADIAN BORDER TODAY.
A COLD FRONT WILL MOVE ACROSS THE AREA TONIGHT FOR MORE RAIN
AND WINDY CONDITIONS. RAIN WILL CONTINUE ON THANKSGIVING DAY AS
ANOTHER COLD FRONT APPROACHES FROM THE NORTH THEN CROSSES THE AREA
ON FRIDAY. COOL DRY AND BREEZY WEATHER WILL DEVELOP BY FRIDAY
AFTERNOON AND CONTINUE THROUGH THE WEEKEND AS HIGH PRESSURE BUILDS
OVER BRITISH COLUMBIA.

&&

.SHORT TERM...WESTERN WASHINGTON IS IN THE WARM SECTOR AS A WARM
FRONT LIFTED NORTH THROUGH THE REGION OVERNIGHT. AS A RESULT...TEMPS
REMAINED MILD WITH READINGS MAINLY IN THE 50S THIS MORNING. THE WARM
FRONT IS OVER SOUTHERN B.C. NOW AND RAIN WILL MAINLY AFFECT THE
NORTHERN EDGE OF THE CWA TODAY...AND ALSO THE MOUNTAINS. RIVERS ARE
STILL RISING AND FLOOD WATCHES AND WARNING ARE IN EFFECT...SEE
HYDROLOGY DISCUSSION BELOW. TEMPS WILL REMAIN MILD THIS AFTERNOON
WITH HIGHS IN THE MID TO UPPER 50S.

RAIN WILL INCREASE IN COVERAGE TONIGHT THROUGH THURSDAY AS A COLD
FRONT MOVES INLAND. SE PRESSURE GRADIENTS WILL TIGHTEN AS THIS
SYSTEM APPROACHES AND MAY SEE WIND ADVISORY SPEEDS ALONG THE COAST
AND NORTH INTERIOR ZONES TONIGHT. THIS FRONT WILL BRING ANOTHER SHOT
OF HEAVY RAIN TO THE MOUNTAINS...LEADING TO MORE FLOOD CONCERNS.
SNOW LEVELS WILL REMAIN HIGH AT 6000 TO 7000 FT. EXPECT RAIN AT
TIMES IN THE LOWLANDS THROUGHOUT THANKSGIVING DAY.

ANOTHER COLD FRONT WILL CROSS FROM NW TO SE THROUGH WESTERN WA ON
FRIDAY...BRINGING MORE RAIN AND WINDY CONDITIONS. THIS FRONT SHOULD
EXIT SOUTH FRI AFTERNOON. MODELS ARE SHOWING GUSTY FRASER RIVER
OUTFLOW WINDS FRI AFTERNOON OR EVENING AS STRONG HIGH PRES OVER
INTERIOR B.C. SAGS SOUTH. THIS COOL AND DRY AIR WILL FILTER SOUTH
INTO WESTERN WA FRI NIGHT. THE AIR MASS WILL BE COOL AND UNSTABLE AS
A DEEP UPPER TROUGH ALSO CLIPS WESTERN WA DURING THIS PERIOD. THERE
IS A CHANCE OF SNOW IN THE INTERIOR FRI NIGHT INTO SAT MORNING AS
THIS TROUGH CROSSES THE REGION. MODELS ARE NOW TRYING TO FORM A
CONVERGENCE ZONE WHERE COOL NORTHERLY FRASER OUTFLOW MEETS THE MOIST
S/SW ONSHORE FLOW. COULD SEE RAIN/SNOW IN THE CONVERGENCE ZONE. BUT
THIS COULD OCCUR ANYWHERE IN THE INTERIOR. TOUGH TO PIN THIS DOWN
EXACTLY BUT DEFINITELY NEED TO KEEP A CLOSE EYE IF THIS SCENARIO
PANS OUT. MODELS DO SHOW THE TROUGH EXITING SAT MORNING WITH DRY
WEATHER EXPECTED. 33

.LONG TERM...LONG RANGE MODELS SHOW A COOL AND DRY AIR MASS OVER
WESTERN WA ON SUNDAY. HIGH PRES OVER INTERIOR B.C. WILL MAINTAIN
EASTERLY FLOW THROUGH THE PASSES. LOWS SUNDAY MORNING WILL BE DOWN
TO THE 20S TO LOWER 30S ONCE AGAIN. HIGHS ARE ALSO BELOW NORMAL ON
SUNDAY WITH UPPER 30S TO LOWER 40S EXPECTED. MODELS WERE SHOWING
SOME MOISTURE SPREADING NORTH SUN NIGHT OR MON BUT THEY ARE NOW
BACKING OFF ON THIS IDEA. SO THE FORECAST IS NOW LOOKING DRIER OVER
THIS PERIOD AS WELL. THE FORECAST IS ALSO LOOKING DRIER THROUGH
MIDWEEK NOW AS THE EURO TRIES TO BUILD A RIDGE OVER THE PAC NW. 33

&&

.HYDROLOGY...RAIN RATES HAVE DECREASED THROUGHOUT THE CASCADES
OVERNIGHT...WHILE THE WARM FRONT HAS CONTINUED MOVING SLOWLY
NORTHWARD. RAINFALL AMOUNTS OF 0.5 TO 1.2 INCHES DURING THE PAST 6
HOURS WERE STILL COMMON FROM THE STILLAGUAMISH BASIN NORTHWARD...BUT
RATES THERE SHOULD DECREASE THIS MORNING. THE STILLAGUAMISH REACHED
FLOOD STAGE EARLY THIS MORNING...AND FLOODING IS STILL A SHORT TERM
CONCERN FOR THE NOOKSACK RIVER.

THERE HAS NOT BEEN MUCH RAIN OVERNIGHT SOUTH OF THE STILLAGUAMISH
BASIN -- GENERALLY 0.5 INCH OR LESS. THE THREE FORKS OF THE
SNOQUALMIE RIVER APPEAR TO HAVE CRESTED...SO THE SNOQUALMIE AT THE
FALLS SHOULD CREST EARLY THIS MORNING WITH THE CREST MOVING
DOWNSTREAM THROUGH CARNATION LATE THIS AFTERNOON. FLOODING ON THE
SNOQUALMIE WILL CONTINUE THROUGH TONIGHT. THE SKYKOMISH RIVER HAS
BEEN RUNNING WITHIN A FOOT OF FLOOD STAGE...BUT IT WILL PROBABLY
BEGIN FALLING SOON. THE SNOHOMISH...WHICH IS FORMED BY THE
CONFLUENCE OF THE SKYKOMISH AND SNOQUALMIE RIVERS...COULD HAVE SOME
FLOODING LATER TODAY.

THE RIVERS THAT FLOW OFF MOUNT RAINIER ARE RECEDING. THE FLOODING
HAS ENDED FOR THE CARBON AND NISQUALLY RIVERS...BUT FLOODING WILL
CONTINUE FOR THE COWLITZ AND REACH OF THE PUYALLUP NEAR ORTING.

NEXT WE TURN OUR ATTENTION TO THE FRONTAL SYSTEM THAT WILL BRING
SIGNIFICANT RAINFALL TONIGHT THROUGH THURSDAY NIGHT. WE ARE
EXPECTING STORM TOTALS IN THE MOUNTAINS OF 3 TO 5 INCHES DURING THE
36 HOURS FROM 4 PM TODAY THROUGH 4 AM FRIDAY. THE OLYMPICS AND NORTH
CASCADES WILL RECEIVE THE HEAVIEST RAINFALL...BUT LOCALLY UP TO 5
INCHES OVER MOUNT RAINIER AND SKYKOMISH-SNOQUALMIE-TOLT-SNOHOMISH
BASIN IS POSSIBLE TOO. THE SNOW LEVEL WILL BE 5500 TO 7000 FT FOR
MOST OF THE EVENT...THEN FALL ON FRIDAY AS A COLD FRONT MOVES
THROUGH FROM THE NORTHWEST AND PRECIPITATION DECREASES.

A MAJOR FLOODING EPISODE IS UNLIKELY...BUT THE RAINFALL COULD
CERTAINLY RENEW FLOODING ON THE RIVERS THAT FLOODED OR ALMOST
FLOODED AND SOME OTHER RIVERS COULD REACH FLOOD STAGE AS WELL. A
FLOOD WATCH IS IN EFFECT THROUGH FRIDAY...WHICH INCLUDES ALL THE
COUNTIES WITH RIVERS FLOWING OFF THE WEST SLOPES OF THE CASCADES AND
MASON COUNTY FOR THE POSSIBILITY OF A FLOOD ON THE SKOKOMISH.

COLDER AND DRIER WEATHER IS LIKELY THIS WEEKEND...SO RIVERS SHOULD
RECEDE AND THE FLOOD THREAT WILL END FOR THE FORESEEABLE FUTURE.
MCDONNAL

&&

.AVIATION...THE WARM FRONT THAT BROUGHT ALL THE RAIN TO WESTERN
WASHINGTON THE PAST COUPLE DAYS HAS MOVED INTO BRITISH COLUMBIA.
HOWEVER A WARM MOIST AIR MASS REMAINS OVER WESTERN WASHINGTON WITH
WIDESPREAD LOW-END MVFR TO IFR CONDITIONS...INCLUDING SOME
VISIBILITIES BELOW 3SM IN FOG AND LIGHT PRECIPITATION.

IMPROVEMENT TODAY WILL BE GRADUAL AND MAINLY LIMITED TO THE PUGET
SOUND REGION AND SOUTHWEST INTERIOR. ANOTHER VIGOROUS FRONTAL SYSTEM
WILL BRING MORE RAIN TO THE COAST LATE TODAY...SPREADING INTO THE
WESTERN WASHINGTON INTERIOR THIS EVENING. WHATEVER IMPROVEMENT
OCCURS TODAY IS LIKELY TO BE QUICKLY UNDONE AS A RESULT.

KSEA...SOUTH WIND MOSTLY 10-16 KT GUSTING 24 KT THROUGH TONIGHT...
EXCEPT THERE COULD BE A BRIEF LULL LATE THIS MORNING AND AFTERNOON.
THE GRADUAL IMPROVEMENT IN CEILINGS SHOULD CONTINUE TODAY...BUT
CONDITIONS WILL DETERIORATE TONIGHT AS THE NEXT FRONTAL SYSTEM
ARRIVES.   MCDONNAL

&&

.MARINE...A COLD FRONT WILL APPROACH THE WATERS TODAY AND MOVE
ONSHORE TONIGHT. SMALL CRAFT ADVISORY SOUTHERLY WINDS WILL BE COMMON
MOST WATERS TODAY...THEN GALES FOR SOME WATERS TONIGHT AS THE FRONT
MOVES THROUGH. MODERATE TO STRONG ONSHORE FLOW WILL PREVAIL BEHIND
THE FRONT ON THURSDAY.

ANOTHER COLD FRONT WILL MOVE THROUGH THE WATERS ON FRIDAY. THIS
FRONT WILL BE FOLLOWED BY STRONG FRASER OUTFLOW IN THE NORTHERN
INLAND WATERS AND MODERATE NORTHERLY WINDS OVER THE OTHER WATERS
LATER FRIDAY INTO SATURDAY. SCHNEIDER

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...FLOOD WATCHES AND WARNINGS IN EFFECT FOR PORTIONS OF
     WESTERN WASHINGTON.
PZ...SMALL CRAFT ADVISORY ALL WATERS.
    .SMALL CRAFT ADVISORY GRAYS HARBOR BAR FOR ROUGH BAR.
    .GALE WARNING COASTAL WATERS...ENTRANCES STRAIT OF JUAN DE
     FUCA...AND NORTHERN INLAND WATERS LATE THIS AFTERNOON AND
     TONIGHT.

&&

$$

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000
FXUS66 KSEW 261104
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
330 AM PST WED NOV 26 2014

.SYNOPSIS...A WARM FRONT WILL REMAIN NEAR THE CANADIAN BORDER TODAY.
A COLD FRONT WILL MOVE ACROSS THE AREA TONIGHT FOR MORE RAIN
AND WINDY CONDITIONS. RAIN WILL CONTINUE ON THANKSGIVING DAY AS
ANOTHER COLD FRONT APPROACHES FROM THE NORTH THEN CROSSES THE AREA
ON FRIDAY. COOL DRY AND BREEZY WEATHER WILL DEVELOP BY FRIDAY
AFTERNOON AND CONTINUE THROUGH THE WEEKEND AS HIGH PRESSURE BUILDS
OVER BRITISH COLUMBIA.

&&

.SHORT TERM...WESTERN WASHINGTON IS IN THE WARM SECTOR AS A WARM
FRONT LIFTED NORTH THROUGH THE REGION OVERNIGHT. AS A RESULT...TEMPS
REMAINED MILD WITH READINGS MAINLY IN THE 50S THIS MORNING. THE WARM
FRONT IS OVER SOUTHERN B.C. NOW AND RAIN WILL MAINLY AFFECT THE
NORTHERN EDGE OF THE CWA TODAY...AND ALSO THE MOUNTAINS. RIVERS ARE
STILL RISING AND FLOOD WATCHES AND WARNING ARE IN EFFECT...SEE
HYDROLOGY DISCUSSION BELOW. TEMPS WILL REMAIN MILD THIS AFTERNOON
WITH HIGHS IN THE MID TO UPPER 50S.

RAIN WILL INCREASE IN COVERAGE TONIGHT THROUGH THURSDAY AS A COLD
FRONT MOVES INLAND. SE PRESSURE GRADIENTS WILL TIGHTEN AS THIS
SYSTEM APPROACHES AND MAY SEE WIND ADVISORY SPEEDS ALONG THE COAST
AND NORTH INTERIOR ZONES TONIGHT. THIS FRONT WILL BRING ANOTHER SHOT
OF HEAVY RAIN TO THE MOUNTAINS...LEADING TO MORE FLOOD CONCERNS.
SNOW LEVELS WILL REMAIN HIGH AT 6000 TO 7000 FT. EXPECT RAIN AT
TIMES IN THE LOWLANDS THROUGHOUT THANKSGIVING DAY.

ANOTHER COLD FRONT WILL CROSS FROM NW TO SE THROUGH WESTERN WA ON
FRIDAY...BRINGING MORE RAIN AND WINDY CONDITIONS. THIS FRONT SHOULD
EXIT SOUTH FRI AFTERNOON. MODELS ARE SHOWING GUSTY FRASER RIVER
OUTFLOW WINDS FRI AFTERNOON OR EVENING AS STRONG HIGH PRES OVER
INTERIOR B.C. SAGS SOUTH. THIS COOL AND DRY AIR WILL FILTER SOUTH
INTO WESTERN WA FRI NIGHT. THE AIR MASS WILL BE COOL AND UNSTABLE AS
A DEEP UPPER TROUGH ALSO CLIPS WESTERN WA DURING THIS PERIOD. THERE
IS A CHANCE OF SNOW IN THE INTERIOR FRI NIGHT INTO SAT MORNING AS
THIS TROUGH CROSSES THE REGION. MODELS ARE NOW TRYING TO FORM A
CONVERGENCE ZONE WHERE COOL NORTHERLY FRASER OUTFLOW MEETS THE MOIST
S/SW ONSHORE FLOW. COULD SEE RAIN/SNOW IN THE CONVERGENCE ZONE. BUT
THIS COULD OCCUR ANYWHERE IN THE INTERIOR. TOUGH TO PIN THIS DOWN
EXACTLY BUT DEFINITELY NEED TO KEEP A CLOSE EYE IF THIS SCENARIO
PANS OUT. MODELS DO SHOW THE TROUGH EXITING SAT MORNING WITH DRY
WEATHER EXPECTED. 33

.LONG TERM...LONG RANGE MODELS SHOW A COOL AND DRY AIR MASS OVER
WESTERN WA ON SUNDAY. HIGH PRES OVER INTERIOR B.C. WILL MAINTAIN
EASTERLY FLOW THROUGH THE PASSES. LOWS SUNDAY MORNING WILL BE DOWN
TO THE 20S TO LOWER 30S ONCE AGAIN. HIGHS ARE ALSO BELOW NORMAL ON
SUNDAY WITH UPPER 30S TO LOWER 40S EXPECTED. MODELS WERE SHOWING
SOME MOISTURE SPREADING NORTH SUN NIGHT OR MON BUT THEY ARE NOW
BACKING OFF ON THIS IDEA. SO THE FORECAST IS NOW LOOKING DRIER OVER
THIS PERIOD AS WELL. THE FORECAST IS ALSO LOOKING DRIER THROUGH
MIDWEEK NOW AS THE EURO TRIES TO BUILD A RIDGE OVER THE PAC NW. 33

&&

.HYDROLOGY...RAIN RATES HAVE DECREASED THROUGHOUT THE CASCADES
OVERNIGHT...WHILE THE WARM FRONT HAS CONTINUED MOVING SLOWLY
NORTHWARD. RAINFALL AMOUNTS OF 0.5 TO 1.2 INCHES DURING THE PAST 6
HOURS WERE STILL COMMON FROM THE STILLAGUAMISH BASIN NORTHWARD...BUT
RATES THERE SHOULD DECREASE THIS MORNING. THE STILLAGUAMISH REACHED
FLOOD STAGE EARLY THIS MORNING...AND FLOODING IS STILL A SHORT TERM
CONCERN FOR THE NOOKSACK RIVER.

THERE HAS NOT BEEN MUCH RAIN OVERNIGHT SOUTH OF THE STILLAGUAMISH
BASIN -- GENERALLY 0.5 INCH OR LESS. THE THREE FORKS OF THE
SNOQUALMIE RIVER APPEAR TO HAVE CRESTED...SO THE SNOQUALMIE AT THE
FALLS SHOULD CREST EARLY THIS MORNING WITH THE CREST MOVING
DOWNSTREAM THROUGH CARNATION LATE THIS AFTERNOON. FLOODING ON THE
SNOQUALMIE WILL CONTINUE THROUGH TONIGHT. THE SKYKOMISH RIVER HAS
BEEN RUNNING WITHIN A FOOT OF FLOOD STAGE...BUT IT WILL PROBABLY
BEGIN FALLING SOON. THE SNOHOMISH...WHICH IS FORMED BY THE
CONFLUENCE OF THE SKYKOMISH AND SNOQUALMIE RIVERS...COULD HAVE SOME
FLOODING LATER TODAY.

THE RIVERS THAT FLOW OFF MOUNT RAINIER ARE RECEDING. THE FLOODING
HAS ENDED FOR THE CARBON AND NISQUALLY RIVERS...BUT FLOODING WILL
CONTINUE FOR THE COWLITZ AND REACH OF THE PUYALLUP NEAR ORTING.

NEXT WE TURN OUR ATTENTION TO THE FRONTAL SYSTEM THAT WILL BRING
SIGNIFICANT RAINFALL TONIGHT THROUGH THURSDAY NIGHT. WE ARE
EXPECTING STORM TOTALS IN THE MOUNTAINS OF 3 TO 5 INCHES DURING THE
36 HOURS FROM 4 PM TODAY THROUGH 4 AM FRIDAY. THE OLYMPICS AND NORTH
CASCADES WILL RECEIVE THE HEAVIEST RAINFALL...BUT LOCALLY UP TO 5
INCHES OVER MOUNT RAINIER AND SKYKOMISH-SNOQUALMIE-TOLT-SNOHOMISH
BASIN IS POSSIBLE TOO. THE SNOW LEVEL WILL BE 5500 TO 7000 FT FOR
MOST OF THE EVENT...THEN FALL ON FRIDAY AS A COLD FRONT MOVES
THROUGH FROM THE NORTHWEST AND PRECIPITATION DECREASES.

A MAJOR FLOODING EPISODE IS UNLIKELY...BUT THE RAINFALL COULD
CERTAINLY RENEW FLOODING ON THE RIVERS THAT FLOODED OR ALMOST
FLOODED AND SOME OTHER RIVERS COULD REACH FLOOD STAGE AS WELL. A
FLOOD WATCH IS IN EFFECT THROUGH FRIDAY...WHICH INCLUDES ALL THE
COUNTIES WITH RIVERS FLOWING OFF THE WEST SLOPES OF THE CASCADES AND
MASON COUNTY FOR THE POSSIBILITY OF A FLOOD ON THE SKOKOMISH.

COLDER AND DRIER WEATHER IS LIKELY THIS WEEKEND...SO RIVERS SHOULD
RECEDE AND THE FLOOD THREAT WILL END FOR THE FORESEEABLE FUTURE.
MCDONNAL

&&

.AVIATION...THE WARM FRONT THAT BROUGHT ALL THE RAIN TO WESTERN
WASHINGTON THE PAST COUPLE DAYS HAS MOVED INTO BRITISH COLUMBIA.
HOWEVER A WARM MOIST AIR MASS REMAINS OVER WESTERN WASHINGTON WITH
WIDESPREAD LOW-END MVFR TO IFR CONDITIONS...INCLUDING SOME
VISIBILITIES BELOW 3SM IN FOG AND LIGHT PRECIPITATION.

IMPROVEMENT TODAY WILL BE GRADUAL AND MAINLY LIMITED TO THE PUGET
SOUND REGION AND SOUTHWEST INTERIOR. ANOTHER VIGOROUS FRONTAL SYSTEM
WILL BRING MORE RAIN TO THE COAST LATE TODAY...SPREADING INTO THE
WESTERN WASHINGTON INTERIOR THIS EVENING. WHATEVER IMPROVEMENT
OCCURS TODAY IS LIKELY TO BE QUICKLY UNDONE AS A RESULT.

KSEA...SOUTH WIND MOSTLY 10-16 KT GUSTING 24 KT THROUGH TONIGHT...
EXCEPT THERE COULD BE A BRIEF LULL LATE THIS MORNING AND AFTERNOON.
THE GRADUAL IMPROVEMENT IN CEILINGS SHOULD CONTINUE TODAY...BUT
CONDITIONS WILL DETERIORATE TONIGHT AS THE NEXT FRONTAL SYSTEM
ARRIVES.   MCDONNAL

&&

.MARINE...A COLD FRONT WILL APPROACH THE WATERS TODAY AND MOVE
ONSHORE TONIGHT. SMALL CRAFT ADVISORY SOUTHERLY WINDS WILL BE COMMON
MOST WATERS TODAY...THEN GALES FOR SOME WATERS TONIGHT AS THE FRONT
MOVES THROUGH. MODERATE TO STRONG ONSHORE FLOW WILL PREVAIL BEHIND
THE FRONT ON THURSDAY.

ANOTHER COLD FRONT WILL MOVE THROUGH THE WATERS ON FRIDAY. THIS
FRONT WILL BE FOLLOWED BY STRONG FRASER OUTFLOW IN THE NORTHERN
INLAND WATERS AND MODERATE NORTHERLY WINDS OVER THE OTHER WATERS
LATER FRIDAY INTO SATURDAY. SCHNEIDER

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...FLOOD WATCHES AND WARNINGS IN EFFECT FOR PORTIONS OF
     WESTERN WASHINGTON.
PZ...SMALL CRAFT ADVISORY ALL WATERS.
    .SMALL CRAFT ADVISORY GRAYS HARBOR BAR FOR ROUGH BAR.
    .GALE WARNING COASTAL WATERS...ENTRANCES STRAIT OF JUAN DE
     FUCA...AND NORTHERN INLAND WATERS LATE THIS AFTERNOON AND
     TONIGHT.

&&

$$

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000
FXUS66 KOTX 261042
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
242 AM PST WED NOV 26 2014

.SYNOPSIS...
Mild and breezy weather is expected today and Thanksgiving. By
late this morning, snow levels should rise above the mountain
passes. Motorists with plans to travel over the mountain passes
should experience good conditions this afternoon through Friday
afternoon. The arrival of a cold front Friday night into Saturday
will bring winter driving conditions to the mountain passes and
much cooler weather for the weekend.

&&

.DISCUSSION...

Today: The axis of the heaviest precipitation will continue to
migrate northward today as the jet stream is shunted Alberta and
Montana. Forecasting snow levels in the northern Cascades,
northeast Washington and far north Idaho over the last 24 hour has
been brutal. There has been a tremendously tight gradient between
snow levels of 6000 feet in places like Stevens Pass and the
valley floor in the Methow Valley. Fortunately this morning,
precipitation amounts will not be as heavy as they were yesterday
afternoon and evening. An additional 1 to 3 inches of snow
accumulation is expected this morning over the Pasayten Wilderness
to Sherman Pass to the mountains near Sandpoint. Another inch or
two of accumulation will also be possible early this morning over
Lookout Pass before snow transitions to rain shortly after
sunrise. Winter Weather Advisories will remain in effect through
10 AM for Lookout Pass and the northern portions of Stevens, Pend
Oreille, Bonner and Boundary counties.

The temperature forecast has been lowered along the East Slopes of
the Cascades, Waterville Plateau into the Moses Lake area. Thick
low clouds and fog will likely linger for a good portion of the
day. For the Palouse, West Plains and Ritzville areas, south winds
of 10 to 15 mph should develop by late morning providing mixing to
warm temperatures into the 40s and 50s.

Tonight into Thanksgiving: Snow levels will be at or above 6000
feet for Idaho and Washington tonight into Thanksgiving. Mountain
passes will experience periods of rain during this busy holiday
travel period, but the roads should be in relatively good shape.
Thanksgiving has the potential to be one of the warmest days of
the month. Despite mostly cloudy conditions, breezy southwest
winds will provide the mixing needed this time of year to push
temperatures into the 50s over much of the region. /GKoch

Friday through Sunday night...The region will start out under a
relatively warm and wet pattern Friday then transition to a much
colder but drier regime over the weekend. Westerly flow aloft will
continue to direct a moisture laden fetch across the region
Friday. The areas most favored for precipitation will be the
Cascade crest and the rising terrain north and east of the
Columbia Basin. The entire eastern half of the forecast area will
likely see a decent amount of precip as a surface low tracks south
from southeast British Columbia into central Idaho by Saturday.
Right now models are generally tracking it through the Idaho
panhandle but the precise track will determine how far west into
the basin the precip will extend. QPF could easily top an inch or
two for north Idaho as the low slowly sinks south. Snow levels
will start out quite high, ranging from 5k to 7k ft. Only the
highest peaks will see snow on Friday.

An arctic front will drop south across the forecast area Friday night
and Saturday, bringing in much drier and colder air, chasing
precip to the southeast zones by Saturday evening. Plunging snow
levels will allow accumulating snow for the southeast valleys with
possible winter highlight criteria being achieved, particularly
for the Camas Prairie on Saturday. Temperatures will plummet
Friday night with single digits for the typical cold spots in the
northern valleys. Most locations will see a 20 to 30 degree drop
overnight with only the southernmost valleys escaping freezing
temps. As the low drops south, the building arctic high over BC
will strengthen the surface pressure gradient between them. Winds
will increase down the north-south valleys and be funneled down
the Purcell trench and into the west Plains and basin. Expect wind
chill temperatures below zero in the Okanogan valley where the
strongest winds and very cold temps will prevail.

Cold conditions will continue Saturday night and Sunday with much
of the forecast area remaining dry. The exception will be the
southernmost counties where the surface front will stall. Surface
winds will diminish but remain northerly, reinforcing the cold air
in the valleys. Southwest flow ahead of the next Pacific trough
will result in strong warm air advection in the mid levels for
Sunday night into Monday. This layer of warm air overrunning the
resident cold air at the surface could bring mixed precipitation
to the Columbia Basin, Wenatchee Valley, L-C valley and possibly
as far north as the Spokane area. Temperature profiles for the
northern valleys appear to be cold enough to support all snow.
/Kelch

Monday through Wednesday: An active weather pattern is expected to
continue through this period. The GFS has been more consistent
with pushing warm moist air mass form the Southwest into the
region compared with the ECMWF which is depicting a dry Northwest
flow. This set up is expected to bring widespread precip to the
region. Snow for most locations in the Inland Northwest excluding
the rain for the Palouse and Camas Prairie areas through Tuesday
morning. A small ridge is expected to begin to build in the region
on Tuesday and bring a decrease in the precip Columbia Basin and
continues snow to the Cascades, Idaho Panhandle, and Canadian
Border regions. Temperatures are expected to range from upper 20s
for highs and low teens for lows. /JDC

&&

.AVIATION...
06Z TAFS: A warm front will gradually lift into the region,
eventually overwhelming the colder air at the surface. Look for
periods of rain and snow toward the GEG to COE...PUW and in the
vcnty of EAT/LWS through the night, with the threat waning toward
12Z at most sites. The threat will linger longer near COE. In this
set-up look for IFR/LCL MVFR conditions, with stratus and fog. The
fog may be locally dense in spots, with the best confidence near
GEG at this time. Conditions are expected to improve somewhat
after 16-19Z, with cigs lifting slightly toward high IFR/MVFR
conditions around the eastern TAF sites and MVFR/VFR conditions
elsewhere. /J. Cote`




&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        45  42  50  40  45  26 /  80  30  30  20  80  60
Coeur d`Alene  44  41  48  40  44  27 /  90  30  30  20  90  70
Pullman        54  44  53  42  48  31 /  30  30  30  20  80  80
Lewiston       56  47  58  45  52  37 /  10  10  10  20  70  80
Colville       38  38  46  38  42  20 /  90  60  50  40  80  10
Sandpoint      39  38  45  37  41  25 / 100  70  60  50  90  50
Kellogg        43  40  44  38  40  29 / 100  60  70  70  90  80
Moses Lake     46  44  55  40  50  25 /  10  10  10  10  30  20
Wenatchee      43  42  50  41  47  27 /  10  10  10  20  30  10
Omak           38  38  46  35  40  14 /  50  30  30  30  50  10

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Winter Weather Advisory until 10 AM PST this morning for Central
     Panhandle Mountains-Northern Panhandle.

WA...Winter Weather Advisory until 10 AM PST this morning for
     Northeast Mountains.

&&

$$




000
FXUS66 KOTX 261042
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
242 AM PST WED NOV 26 2014

.SYNOPSIS...
Mild and breezy weather is expected today and Thanksgiving. By
late this morning, snow levels should rise above the mountain
passes. Motorists with plans to travel over the mountain passes
should experience good conditions this afternoon through Friday
afternoon. The arrival of a cold front Friday night into Saturday
will bring winter driving conditions to the mountain passes and
much cooler weather for the weekend.

&&

.DISCUSSION...

Today: The axis of the heaviest precipitation will continue to
migrate northward today as the jet stream is shunted Alberta and
Montana. Forecasting snow levels in the northern Cascades,
northeast Washington and far north Idaho over the last 24 hour has
been brutal. There has been a tremendously tight gradient between
snow levels of 6000 feet in places like Stevens Pass and the
valley floor in the Methow Valley. Fortunately this morning,
precipitation amounts will not be as heavy as they were yesterday
afternoon and evening. An additional 1 to 3 inches of snow
accumulation is expected this morning over the Pasayten Wilderness
to Sherman Pass to the mountains near Sandpoint. Another inch or
two of accumulation will also be possible early this morning over
Lookout Pass before snow transitions to rain shortly after
sunrise. Winter Weather Advisories will remain in effect through
10 AM for Lookout Pass and the northern portions of Stevens, Pend
Oreille, Bonner and Boundary counties.

The temperature forecast has been lowered along the East Slopes of
the Cascades, Waterville Plateau into the Moses Lake area. Thick
low clouds and fog will likely linger for a good portion of the
day. For the Palouse, West Plains and Ritzville areas, south winds
of 10 to 15 mph should develop by late morning providing mixing to
warm temperatures into the 40s and 50s.

Tonight into Thanksgiving: Snow levels will be at or above 6000
feet for Idaho and Washington tonight into Thanksgiving. Mountain
passes will experience periods of rain during this busy holiday
travel period, but the roads should be in relatively good shape.
Thanksgiving has the potential to be one of the warmest days of
the month. Despite mostly cloudy conditions, breezy southwest
winds will provide the mixing needed this time of year to push
temperatures into the 50s over much of the region. /GKoch

Friday through Sunday night...The region will start out under a
relatively warm and wet pattern Friday then transition to a much
colder but drier regime over the weekend. Westerly flow aloft will
continue to direct a moisture laden fetch across the region
Friday. The areas most favored for precipitation will be the
Cascade crest and the rising terrain north and east of the
Columbia Basin. The entire eastern half of the forecast area will
likely see a decent amount of precip as a surface low tracks south
from southeast British Columbia into central Idaho by Saturday.
Right now models are generally tracking it through the Idaho
panhandle but the precise track will determine how far west into
the basin the precip will extend. QPF could easily top an inch or
two for north Idaho as the low slowly sinks south. Snow levels
will start out quite high, ranging from 5k to 7k ft. Only the
highest peaks will see snow on Friday.

An arctic front will drop south across the forecast area Friday night
and Saturday, bringing in much drier and colder air, chasing
precip to the southeast zones by Saturday evening. Plunging snow
levels will allow accumulating snow for the southeast valleys with
possible winter highlight criteria being achieved, particularly
for the Camas Prairie on Saturday. Temperatures will plummet
Friday night with single digits for the typical cold spots in the
northern valleys. Most locations will see a 20 to 30 degree drop
overnight with only the southernmost valleys escaping freezing
temps. As the low drops south, the building arctic high over BC
will strengthen the surface pressure gradient between them. Winds
will increase down the north-south valleys and be funneled down
the Purcell trench and into the west Plains and basin. Expect wind
chill temperatures below zero in the Okanogan valley where the
strongest winds and very cold temps will prevail.

Cold conditions will continue Saturday night and Sunday with much
of the forecast area remaining dry. The exception will be the
southernmost counties where the surface front will stall. Surface
winds will diminish but remain northerly, reinforcing the cold air
in the valleys. Southwest flow ahead of the next Pacific trough
will result in strong warm air advection in the mid levels for
Sunday night into Monday. This layer of warm air overrunning the
resident cold air at the surface could bring mixed precipitation
to the Columbia Basin, Wenatchee Valley, L-C valley and possibly
as far north as the Spokane area. Temperature profiles for the
northern valleys appear to be cold enough to support all snow.
/Kelch

Monday through Wednesday: An active weather pattern is expected to
continue through this period. The GFS has been more consistent
with pushing warm moist air mass form the Southwest into the
region compared with the ECMWF which is depicting a dry Northwest
flow. This set up is expected to bring widespread precip to the
region. Snow for most locations in the Inland Northwest excluding
the rain for the Palouse and Camas Prairie areas through Tuesday
morning. A small ridge is expected to begin to build in the region
on Tuesday and bring a decrease in the precip Columbia Basin and
continues snow to the Cascades, Idaho Panhandle, and Canadian
Border regions. Temperatures are expected to range from upper 20s
for highs and low teens for lows. /JDC

&&

.AVIATION...
06Z TAFS: A warm front will gradually lift into the region,
eventually overwhelming the colder air at the surface. Look for
periods of rain and snow toward the GEG to COE...PUW and in the
vcnty of EAT/LWS through the night, with the threat waning toward
12Z at most sites. The threat will linger longer near COE. In this
set-up look for IFR/LCL MVFR conditions, with stratus and fog. The
fog may be locally dense in spots, with the best confidence near
GEG at this time. Conditions are expected to improve somewhat
after 16-19Z, with cigs lifting slightly toward high IFR/MVFR
conditions around the eastern TAF sites and MVFR/VFR conditions
elsewhere. /J. Cote`




&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        45  42  50  40  45  26 /  80  30  30  20  80  60
Coeur d`Alene  44  41  48  40  44  27 /  90  30  30  20  90  70
Pullman        54  44  53  42  48  31 /  30  30  30  20  80  80
Lewiston       56  47  58  45  52  37 /  10  10  10  20  70  80
Colville       38  38  46  38  42  20 /  90  60  50  40  80  10
Sandpoint      39  38  45  37  41  25 / 100  70  60  50  90  50
Kellogg        43  40  44  38  40  29 / 100  60  70  70  90  80
Moses Lake     46  44  55  40  50  25 /  10  10  10  10  30  20
Wenatchee      43  42  50  41  47  27 /  10  10  10  20  30  10
Omak           38  38  46  35  40  14 /  50  30  30  30  50  10

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Winter Weather Advisory until 10 AM PST this morning for Central
     Panhandle Mountains-Northern Panhandle.

WA...Winter Weather Advisory until 10 AM PST this morning for
     Northeast Mountains.

&&

$$




000
FXUS66 KOTX 261042
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
242 AM PST WED NOV 26 2014

.SYNOPSIS...
Mild and breezy weather is expected today and Thanksgiving. By
late this morning, snow levels should rise above the mountain
passes. Motorists with plans to travel over the mountain passes
should experience good conditions this afternoon through Friday
afternoon. The arrival of a cold front Friday night into Saturday
will bring winter driving conditions to the mountain passes and
much cooler weather for the weekend.

&&

.DISCUSSION...

Today: The axis of the heaviest precipitation will continue to
migrate northward today as the jet stream is shunted Alberta and
Montana. Forecasting snow levels in the northern Cascades,
northeast Washington and far north Idaho over the last 24 hour has
been brutal. There has been a tremendously tight gradient between
snow levels of 6000 feet in places like Stevens Pass and the
valley floor in the Methow Valley. Fortunately this morning,
precipitation amounts will not be as heavy as they were yesterday
afternoon and evening. An additional 1 to 3 inches of snow
accumulation is expected this morning over the Pasayten Wilderness
to Sherman Pass to the mountains near Sandpoint. Another inch or
two of accumulation will also be possible early this morning over
Lookout Pass before snow transitions to rain shortly after
sunrise. Winter Weather Advisories will remain in effect through
10 AM for Lookout Pass and the northern portions of Stevens, Pend
Oreille, Bonner and Boundary counties.

The temperature forecast has been lowered along the East Slopes of
the Cascades, Waterville Plateau into the Moses Lake area. Thick
low clouds and fog will likely linger for a good portion of the
day. For the Palouse, West Plains and Ritzville areas, south winds
of 10 to 15 mph should develop by late morning providing mixing to
warm temperatures into the 40s and 50s.

Tonight into Thanksgiving: Snow levels will be at or above 6000
feet for Idaho and Washington tonight into Thanksgiving. Mountain
passes will experience periods of rain during this busy holiday
travel period, but the roads should be in relatively good shape.
Thanksgiving has the potential to be one of the warmest days of
the month. Despite mostly cloudy conditions, breezy southwest
winds will provide the mixing needed this time of year to push
temperatures into the 50s over much of the region. /GKoch

Friday through Sunday night...The region will start out under a
relatively warm and wet pattern Friday then transition to a much
colder but drier regime over the weekend. Westerly flow aloft will
continue to direct a moisture laden fetch across the region
Friday. The areas most favored for precipitation will be the
Cascade crest and the rising terrain north and east of the
Columbia Basin. The entire eastern half of the forecast area will
likely see a decent amount of precip as a surface low tracks south
from southeast British Columbia into central Idaho by Saturday.
Right now models are generally tracking it through the Idaho
panhandle but the precise track will determine how far west into
the basin the precip will extend. QPF could easily top an inch or
two for north Idaho as the low slowly sinks south. Snow levels
will start out quite high, ranging from 5k to 7k ft. Only the
highest peaks will see snow on Friday.

An arctic front will drop south across the forecast area Friday night
and Saturday, bringing in much drier and colder air, chasing
precip to the southeast zones by Saturday evening. Plunging snow
levels will allow accumulating snow for the southeast valleys with
possible winter highlight criteria being achieved, particularly
for the Camas Prairie on Saturday. Temperatures will plummet
Friday night with single digits for the typical cold spots in the
northern valleys. Most locations will see a 20 to 30 degree drop
overnight with only the southernmost valleys escaping freezing
temps. As the low drops south, the building arctic high over BC
will strengthen the surface pressure gradient between them. Winds
will increase down the north-south valleys and be funneled down
the Purcell trench and into the west Plains and basin. Expect wind
chill temperatures below zero in the Okanogan valley where the
strongest winds and very cold temps will prevail.

Cold conditions will continue Saturday night and Sunday with much
of the forecast area remaining dry. The exception will be the
southernmost counties where the surface front will stall. Surface
winds will diminish but remain northerly, reinforcing the cold air
in the valleys. Southwest flow ahead of the next Pacific trough
will result in strong warm air advection in the mid levels for
Sunday night into Monday. This layer of warm air overrunning the
resident cold air at the surface could bring mixed precipitation
to the Columbia Basin, Wenatchee Valley, L-C valley and possibly
as far north as the Spokane area. Temperature profiles for the
northern valleys appear to be cold enough to support all snow.
/Kelch

Monday through Wednesday: An active weather pattern is expected to
continue through this period. The GFS has been more consistent
with pushing warm moist air mass form the Southwest into the
region compared with the ECMWF which is depicting a dry Northwest
flow. This set up is expected to bring widespread precip to the
region. Snow for most locations in the Inland Northwest excluding
the rain for the Palouse and Camas Prairie areas through Tuesday
morning. A small ridge is expected to begin to build in the region
on Tuesday and bring a decrease in the precip Columbia Basin and
continues snow to the Cascades, Idaho Panhandle, and Canadian
Border regions. Temperatures are expected to range from upper 20s
for highs and low teens for lows. /JDC

&&

.AVIATION...
06Z TAFS: A warm front will gradually lift into the region,
eventually overwhelming the colder air at the surface. Look for
periods of rain and snow toward the GEG to COE...PUW and in the
vcnty of EAT/LWS through the night, with the threat waning toward
12Z at most sites. The threat will linger longer near COE. In this
set-up look for IFR/LCL MVFR conditions, with stratus and fog. The
fog may be locally dense in spots, with the best confidence near
GEG at this time. Conditions are expected to improve somewhat
after 16-19Z, with cigs lifting slightly toward high IFR/MVFR
conditions around the eastern TAF sites and MVFR/VFR conditions
elsewhere. /J. Cote`




&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        45  42  50  40  45  26 /  80  30  30  20  80  60
Coeur d`Alene  44  41  48  40  44  27 /  90  30  30  20  90  70
Pullman        54  44  53  42  48  31 /  30  30  30  20  80  80
Lewiston       56  47  58  45  52  37 /  10  10  10  20  70  80
Colville       38  38  46  38  42  20 /  90  60  50  40  80  10
Sandpoint      39  38  45  37  41  25 / 100  70  60  50  90  50
Kellogg        43  40  44  38  40  29 / 100  60  70  70  90  80
Moses Lake     46  44  55  40  50  25 /  10  10  10  10  30  20
Wenatchee      43  42  50  41  47  27 /  10  10  10  20  30  10
Omak           38  38  46  35  40  14 /  50  30  30  30  50  10

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Winter Weather Advisory until 10 AM PST this morning for Central
     Panhandle Mountains-Northern Panhandle.

WA...Winter Weather Advisory until 10 AM PST this morning for
     Northeast Mountains.

&&

$$




000
FXUS66 KOTX 261042
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
242 AM PST WED NOV 26 2014

.SYNOPSIS...
Mild and breezy weather is expected today and Thanksgiving. By
late this morning, snow levels should rise above the mountain
passes. Motorists with plans to travel over the mountain passes
should experience good conditions this afternoon through Friday
afternoon. The arrival of a cold front Friday night into Saturday
will bring winter driving conditions to the mountain passes and
much cooler weather for the weekend.

&&

.DISCUSSION...

Today: The axis of the heaviest precipitation will continue to
migrate northward today as the jet stream is shunted Alberta and
Montana. Forecasting snow levels in the northern Cascades,
northeast Washington and far north Idaho over the last 24 hour has
been brutal. There has been a tremendously tight gradient between
snow levels of 6000 feet in places like Stevens Pass and the
valley floor in the Methow Valley. Fortunately this morning,
precipitation amounts will not be as heavy as they were yesterday
afternoon and evening. An additional 1 to 3 inches of snow
accumulation is expected this morning over the Pasayten Wilderness
to Sherman Pass to the mountains near Sandpoint. Another inch or
two of accumulation will also be possible early this morning over
Lookout Pass before snow transitions to rain shortly after
sunrise. Winter Weather Advisories will remain in effect through
10 AM for Lookout Pass and the northern portions of Stevens, Pend
Oreille, Bonner and Boundary counties.

The temperature forecast has been lowered along the East Slopes of
the Cascades, Waterville Plateau into the Moses Lake area. Thick
low clouds and fog will likely linger for a good portion of the
day. For the Palouse, West Plains and Ritzville areas, south winds
of 10 to 15 mph should develop by late morning providing mixing to
warm temperatures into the 40s and 50s.

Tonight into Thanksgiving: Snow levels will be at or above 6000
feet for Idaho and Washington tonight into Thanksgiving. Mountain
passes will experience periods of rain during this busy holiday
travel period, but the roads should be in relatively good shape.
Thanksgiving has the potential to be one of the warmest days of
the month. Despite mostly cloudy conditions, breezy southwest
winds will provide the mixing needed this time of year to push
temperatures into the 50s over much of the region. /GKoch

Friday through Sunday night...The region will start out under a
relatively warm and wet pattern Friday then transition to a much
colder but drier regime over the weekend. Westerly flow aloft will
continue to direct a moisture laden fetch across the region
Friday. The areas most favored for precipitation will be the
Cascade crest and the rising terrain north and east of the
Columbia Basin. The entire eastern half of the forecast area will
likely see a decent amount of precip as a surface low tracks south
from southeast British Columbia into central Idaho by Saturday.
Right now models are generally tracking it through the Idaho
panhandle but the precise track will determine how far west into
the basin the precip will extend. QPF could easily top an inch or
two for north Idaho as the low slowly sinks south. Snow levels
will start out quite high, ranging from 5k to 7k ft. Only the
highest peaks will see snow on Friday.

An arctic front will drop south across the forecast area Friday night
and Saturday, bringing in much drier and colder air, chasing
precip to the southeast zones by Saturday evening. Plunging snow
levels will allow accumulating snow for the southeast valleys with
possible winter highlight criteria being achieved, particularly
for the Camas Prairie on Saturday. Temperatures will plummet
Friday night with single digits for the typical cold spots in the
northern valleys. Most locations will see a 20 to 30 degree drop
overnight with only the southernmost valleys escaping freezing
temps. As the low drops south, the building arctic high over BC
will strengthen the surface pressure gradient between them. Winds
will increase down the north-south valleys and be funneled down
the Purcell trench and into the west Plains and basin. Expect wind
chill temperatures below zero in the Okanogan valley where the
strongest winds and very cold temps will prevail.

Cold conditions will continue Saturday night and Sunday with much
of the forecast area remaining dry. The exception will be the
southernmost counties where the surface front will stall. Surface
winds will diminish but remain northerly, reinforcing the cold air
in the valleys. Southwest flow ahead of the next Pacific trough
will result in strong warm air advection in the mid levels for
Sunday night into Monday. This layer of warm air overrunning the
resident cold air at the surface could bring mixed precipitation
to the Columbia Basin, Wenatchee Valley, L-C valley and possibly
as far north as the Spokane area. Temperature profiles for the
northern valleys appear to be cold enough to support all snow.
/Kelch

Monday through Wednesday: An active weather pattern is expected to
continue through this period. The GFS has been more consistent
with pushing warm moist air mass form the Southwest into the
region compared with the ECMWF which is depicting a dry Northwest
flow. This set up is expected to bring widespread precip to the
region. Snow for most locations in the Inland Northwest excluding
the rain for the Palouse and Camas Prairie areas through Tuesday
morning. A small ridge is expected to begin to build in the region
on Tuesday and bring a decrease in the precip Columbia Basin and
continues snow to the Cascades, Idaho Panhandle, and Canadian
Border regions. Temperatures are expected to range from upper 20s
for highs and low teens for lows. /JDC

&&

.AVIATION...
06Z TAFS: A warm front will gradually lift into the region,
eventually overwhelming the colder air at the surface. Look for
periods of rain and snow toward the GEG to COE...PUW and in the
vcnty of EAT/LWS through the night, with the threat waning toward
12Z at most sites. The threat will linger longer near COE. In this
set-up look for IFR/LCL MVFR conditions, with stratus and fog. The
fog may be locally dense in spots, with the best confidence near
GEG at this time. Conditions are expected to improve somewhat
after 16-19Z, with cigs lifting slightly toward high IFR/MVFR
conditions around the eastern TAF sites and MVFR/VFR conditions
elsewhere. /J. Cote`




&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        45  42  50  40  45  26 /  80  30  30  20  80  60
Coeur d`Alene  44  41  48  40  44  27 /  90  30  30  20  90  70
Pullman        54  44  53  42  48  31 /  30  30  30  20  80  80
Lewiston       56  47  58  45  52  37 /  10  10  10  20  70  80
Colville       38  38  46  38  42  20 /  90  60  50  40  80  10
Sandpoint      39  38  45  37  41  25 / 100  70  60  50  90  50
Kellogg        43  40  44  38  40  29 / 100  60  70  70  90  80
Moses Lake     46  44  55  40  50  25 /  10  10  10  10  30  20
Wenatchee      43  42  50  41  47  27 /  10  10  10  20  30  10
Omak           38  38  46  35  40  14 /  50  30  30  30  50  10

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Winter Weather Advisory until 10 AM PST this morning for Central
     Panhandle Mountains-Northern Panhandle.

WA...Winter Weather Advisory until 10 AM PST this morning for
     Northeast Mountains.

&&

$$




000
FXUS66 KOTX 260601
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
1000 PM PST TUE NOV 25 2014

.SYNOPSIS...
Mild and wet conditions will continue through Thursday. Snow
levels will be on the rise tonight...but expect some
accumulations for the areas near the Canadian border through
morning. Thanksgiving will be breezy...wet and continued warm.
Then a colder weather pattern is expected for the holiday weekend
with the mountains receiving several rounds of snow. Snow levels
will fall to valley floors by the weekend.



&&

.DISCUSSION...
Evening update: Very messy and tricky weather pattern. The colder
air trapped near the lee of the Cascades, especially the Methow
and Okanogan Valley, has been harder to get out of those crevices
than coins that fell into the couch cushions. So I have been
playing catch up. Earlier this evening reports of snow in this
region have been in the 4 to 8 inch range, with local amounts near
a foot in place such as Mazama deep in the Methow valley closer to
the Cascades and near Molson, around 4000 feet. Recent reports and
a look at area webcams, including around Oroville going toward the
Canadian border show some rather sloppy/white conditions. SSome
snow has also been reported and seen on cameras about the
Waterville Plateau, near and north of the city of Waterville.

I expanded the areal coverage of the Winter Weather Advisory which
was in place here to include more of the Methow and Okanogan
Valley. The snow should continue to impact the region through the
next several hours, then begin to dissipate in intensity and
coverage overnight into Wednesday morning. So continue to look
for some snowfall through about midnight to 2 am, before
dissipating around the 2-4 AM hour.

Precipitation elsewhere has been in and out, but most of the
newest guidance keeps some moderate chance going across east-
central and northeast WA and north ID through at least the early
overnight, before the focus starts to retreat north and east into
the Panhandle by Wednesday morning. I decreased overall PoPs
across the Basin through the Spokane/C`dA area southward. However
they still remain in the lower likely category in that
Spokane/C`dA area and higher Palouse.

Overnight lows will be tricky. Most places may have already
reached their lows for the night, with many models suggesting
temperatures will remain steady or slowly rise overnight
especially away from the northern lee of the Cascades and
sheltered northern valleys. /J. Cote`


&&

.AVIATION...
06Z TAFS: A warm front will gradually lift into the region,
eventually overwhelming the colder air at the surface. Lookf or
periods of rain and snow toward the GEG to COE...PUW and in the
vcnty of EAT/LWS through the night, with the threat waning toward
12Z at most sites. The threat will linger longer near COE. In this
set-up look for IFR/LCL MVFR conditions, with stratus and fog. The
fog may be locally dense in spots, with the best confidence near
GEG at this time. Conditions are expected to improve somewhat
after 16-19Z, with cigs lifting slightly toward high IFR/MVFR
conditions around the eastern TAF sites and MVFR/VFR conditions
elsewhere.  /J. Cote`



&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        35  48  42  49  40  45 /  70  40  30  20  30  70
Coeur d`Alene  35  48  41  47  40  44 /  70  80  50  50  30  80
Pullman        40  54  44  52  42  48 /  70  20  20  10  30  80
Lewiston       44  59  47  55  45  52 /  60  10  10  10  30  70
Colville       36  45  39  45  38  42 /  80  80  60  40  40  70
Sandpoint      33  44  38  43  37  41 /  70  80  70  60  60  80
Kellogg        34  43  40  42  38  39 / 100  90  60  60  60  90
Moses Lake     38  54  44  54  40  51 /  20  10  10  10  20  30
Wenatchee      40  51  42  50  41  46 /  40  10  20  10  40  30
Omak           32  44  38  44  35  41 /  80  40  30  20  50  50

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Winter Weather Advisory until 10 AM PST Wednesday for Northern
     Panhandle.

     Winter Weather Advisory until 4 AM PST Wednesday for Central
     Panhandle Mountains.

WA...Winter Weather Advisory until 10 AM PST Wednesday for Northeast
     Mountains.

     Winter Weather Advisory until 4 AM PST Wednesday for East Slopes
     Northern Cascades-Okanogan Highlands-Okanogan Valley.

&&

$$




000
FXUS66 KOTX 260601
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
1000 PM PST TUE NOV 25 2014

.SYNOPSIS...
Mild and wet conditions will continue through Thursday. Snow
levels will be on the rise tonight...but expect some
accumulations for the areas near the Canadian border through
morning. Thanksgiving will be breezy...wet and continued warm.
Then a colder weather pattern is expected for the holiday weekend
with the mountains receiving several rounds of snow. Snow levels
will fall to valley floors by the weekend.



&&

.DISCUSSION...
Evening update: Very messy and tricky weather pattern. The colder
air trapped near the lee of the Cascades, especially the Methow
and Okanogan Valley, has been harder to get out of those crevices
than coins that fell into the couch cushions. So I have been
playing catch up. Earlier this evening reports of snow in this
region have been in the 4 to 8 inch range, with local amounts near
a foot in place such as Mazama deep in the Methow valley closer to
the Cascades and near Molson, around 4000 feet. Recent reports and
a look at area webcams, including around Oroville going toward the
Canadian border show some rather sloppy/white conditions. SSome
snow has also been reported and seen on cameras about the
Waterville Plateau, near and north of the city of Waterville.

I expanded the areal coverage of the Winter Weather Advisory which
was in place here to include more of the Methow and Okanogan
Valley. The snow should continue to impact the region through the
next several hours, then begin to dissipate in intensity and
coverage overnight into Wednesday morning. So continue to look
for some snowfall through about midnight to 2 am, before
dissipating around the 2-4 AM hour.

Precipitation elsewhere has been in and out, but most of the
newest guidance keeps some moderate chance going across east-
central and northeast WA and north ID through at least the early
overnight, before the focus starts to retreat north and east into
the Panhandle by Wednesday morning. I decreased overall PoPs
across the Basin through the Spokane/C`dA area southward. However
they still remain in the lower likely category in that
Spokane/C`dA area and higher Palouse.

Overnight lows will be tricky. Most places may have already
reached their lows for the night, with many models suggesting
temperatures will remain steady or slowly rise overnight
especially away from the northern lee of the Cascades and
sheltered northern valleys. /J. Cote`


&&

.AVIATION...
06Z TAFS: A warm front will gradually lift into the region,
eventually overwhelming the colder air at the surface. Lookf or
periods of rain and snow toward the GEG to COE...PUW and in the
vcnty of EAT/LWS through the night, with the threat waning toward
12Z at most sites. The threat will linger longer near COE. In this
set-up look for IFR/LCL MVFR conditions, with stratus and fog. The
fog may be locally dense in spots, with the best confidence near
GEG at this time. Conditions are expected to improve somewhat
after 16-19Z, with cigs lifting slightly toward high IFR/MVFR
conditions around the eastern TAF sites and MVFR/VFR conditions
elsewhere.  /J. Cote`



&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        35  48  42  49  40  45 /  70  40  30  20  30  70
Coeur d`Alene  35  48  41  47  40  44 /  70  80  50  50  30  80
Pullman        40  54  44  52  42  48 /  70  20  20  10  30  80
Lewiston       44  59  47  55  45  52 /  60  10  10  10  30  70
Colville       36  45  39  45  38  42 /  80  80  60  40  40  70
Sandpoint      33  44  38  43  37  41 /  70  80  70  60  60  80
Kellogg        34  43  40  42  38  39 / 100  90  60  60  60  90
Moses Lake     38  54  44  54  40  51 /  20  10  10  10  20  30
Wenatchee      40  51  42  50  41  46 /  40  10  20  10  40  30
Omak           32  44  38  44  35  41 /  80  40  30  20  50  50

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Winter Weather Advisory until 10 AM PST Wednesday for Northern
     Panhandle.

     Winter Weather Advisory until 4 AM PST Wednesday for Central
     Panhandle Mountains.

WA...Winter Weather Advisory until 10 AM PST Wednesday for Northeast
     Mountains.

     Winter Weather Advisory until 4 AM PST Wednesday for East Slopes
     Northern Cascades-Okanogan Highlands-Okanogan Valley.

&&

$$




000
FXUS66 KOTX 260601
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
1000 PM PST TUE NOV 25 2014

.SYNOPSIS...
Mild and wet conditions will continue through Thursday. Snow
levels will be on the rise tonight...but expect some
accumulations for the areas near the Canadian border through
morning. Thanksgiving will be breezy...wet and continued warm.
Then a colder weather pattern is expected for the holiday weekend
with the mountains receiving several rounds of snow. Snow levels
will fall to valley floors by the weekend.



&&

.DISCUSSION...
Evening update: Very messy and tricky weather pattern. The colder
air trapped near the lee of the Cascades, especially the Methow
and Okanogan Valley, has been harder to get out of those crevices
than coins that fell into the couch cushions. So I have been
playing catch up. Earlier this evening reports of snow in this
region have been in the 4 to 8 inch range, with local amounts near
a foot in place such as Mazama deep in the Methow valley closer to
the Cascades and near Molson, around 4000 feet. Recent reports and
a look at area webcams, including around Oroville going toward the
Canadian border show some rather sloppy/white conditions. SSome
snow has also been reported and seen on cameras about the
Waterville Plateau, near and north of the city of Waterville.

I expanded the areal coverage of the Winter Weather Advisory which
was in place here to include more of the Methow and Okanogan
Valley. The snow should continue to impact the region through the
next several hours, then begin to dissipate in intensity and
coverage overnight into Wednesday morning. So continue to look
for some snowfall through about midnight to 2 am, before
dissipating around the 2-4 AM hour.

Precipitation elsewhere has been in and out, but most of the
newest guidance keeps some moderate chance going across east-
central and northeast WA and north ID through at least the early
overnight, before the focus starts to retreat north and east into
the Panhandle by Wednesday morning. I decreased overall PoPs
across the Basin through the Spokane/C`dA area southward. However
they still remain in the lower likely category in that
Spokane/C`dA area and higher Palouse.

Overnight lows will be tricky. Most places may have already
reached their lows for the night, with many models suggesting
temperatures will remain steady or slowly rise overnight
especially away from the northern lee of the Cascades and
sheltered northern valleys. /J. Cote`


&&

.AVIATION...
06Z TAFS: A warm front will gradually lift into the region,
eventually overwhelming the colder air at the surface. Lookf or
periods of rain and snow toward the GEG to COE...PUW and in the
vcnty of EAT/LWS through the night, with the threat waning toward
12Z at most sites. The threat will linger longer near COE. In this
set-up look for IFR/LCL MVFR conditions, with stratus and fog. The
fog may be locally dense in spots, with the best confidence near
GEG at this time. Conditions are expected to improve somewhat
after 16-19Z, with cigs lifting slightly toward high IFR/MVFR
conditions around the eastern TAF sites and MVFR/VFR conditions
elsewhere.  /J. Cote`



&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        35  48  42  49  40  45 /  70  40  30  20  30  70
Coeur d`Alene  35  48  41  47  40  44 /  70  80  50  50  30  80
Pullman        40  54  44  52  42  48 /  70  20  20  10  30  80
Lewiston       44  59  47  55  45  52 /  60  10  10  10  30  70
Colville       36  45  39  45  38  42 /  80  80  60  40  40  70
Sandpoint      33  44  38  43  37  41 /  70  80  70  60  60  80
Kellogg        34  43  40  42  38  39 / 100  90  60  60  60  90
Moses Lake     38  54  44  54  40  51 /  20  10  10  10  20  30
Wenatchee      40  51  42  50  41  46 /  40  10  20  10  40  30
Omak           32  44  38  44  35  41 /  80  40  30  20  50  50

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Winter Weather Advisory until 10 AM PST Wednesday for Northern
     Panhandle.

     Winter Weather Advisory until 4 AM PST Wednesday for Central
     Panhandle Mountains.

WA...Winter Weather Advisory until 10 AM PST Wednesday for Northeast
     Mountains.

     Winter Weather Advisory until 4 AM PST Wednesday for East Slopes
     Northern Cascades-Okanogan Highlands-Okanogan Valley.

&&

$$




000
FXUS66 KOTX 260601
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
1000 PM PST TUE NOV 25 2014

.SYNOPSIS...
Mild and wet conditions will continue through Thursday. Snow
levels will be on the rise tonight...but expect some
accumulations for the areas near the Canadian border through
morning. Thanksgiving will be breezy...wet and continued warm.
Then a colder weather pattern is expected for the holiday weekend
with the mountains receiving several rounds of snow. Snow levels
will fall to valley floors by the weekend.



&&

.DISCUSSION...
Evening update: Very messy and tricky weather pattern. The colder
air trapped near the lee of the Cascades, especially the Methow
and Okanogan Valley, has been harder to get out of those crevices
than coins that fell into the couch cushions. So I have been
playing catch up. Earlier this evening reports of snow in this
region have been in the 4 to 8 inch range, with local amounts near
a foot in place such as Mazama deep in the Methow valley closer to
the Cascades and near Molson, around 4000 feet. Recent reports and
a look at area webcams, including around Oroville going toward the
Canadian border show some rather sloppy/white conditions. SSome
snow has also been reported and seen on cameras about the
Waterville Plateau, near and north of the city of Waterville.

I expanded the areal coverage of the Winter Weather Advisory which
was in place here to include more of the Methow and Okanogan
Valley. The snow should continue to impact the region through the
next several hours, then begin to dissipate in intensity and
coverage overnight into Wednesday morning. So continue to look
for some snowfall through about midnight to 2 am, before
dissipating around the 2-4 AM hour.

Precipitation elsewhere has been in and out, but most of the
newest guidance keeps some moderate chance going across east-
central and northeast WA and north ID through at least the early
overnight, before the focus starts to retreat north and east into
the Panhandle by Wednesday morning. I decreased overall PoPs
across the Basin through the Spokane/C`dA area southward. However
they still remain in the lower likely category in that
Spokane/C`dA area and higher Palouse.

Overnight lows will be tricky. Most places may have already
reached their lows for the night, with many models suggesting
temperatures will remain steady or slowly rise overnight
especially away from the northern lee of the Cascades and
sheltered northern valleys. /J. Cote`


&&

.AVIATION...
06Z TAFS: A warm front will gradually lift into the region,
eventually overwhelming the colder air at the surface. Lookf or
periods of rain and snow toward the GEG to COE...PUW and in the
vcnty of EAT/LWS through the night, with the threat waning toward
12Z at most sites. The threat will linger longer near COE. In this
set-up look for IFR/LCL MVFR conditions, with stratus and fog. The
fog may be locally dense in spots, with the best confidence near
GEG at this time. Conditions are expected to improve somewhat
after 16-19Z, with cigs lifting slightly toward high IFR/MVFR
conditions around the eastern TAF sites and MVFR/VFR conditions
elsewhere.  /J. Cote`



&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        35  48  42  49  40  45 /  70  40  30  20  30  70
Coeur d`Alene  35  48  41  47  40  44 /  70  80  50  50  30  80
Pullman        40  54  44  52  42  48 /  70  20  20  10  30  80
Lewiston       44  59  47  55  45  52 /  60  10  10  10  30  70
Colville       36  45  39  45  38  42 /  80  80  60  40  40  70
Sandpoint      33  44  38  43  37  41 /  70  80  70  60  60  80
Kellogg        34  43  40  42  38  39 / 100  90  60  60  60  90
Moses Lake     38  54  44  54  40  51 /  20  10  10  10  20  30
Wenatchee      40  51  42  50  41  46 /  40  10  20  10  40  30
Omak           32  44  38  44  35  41 /  80  40  30  20  50  50

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Winter Weather Advisory until 10 AM PST Wednesday for Northern
     Panhandle.

     Winter Weather Advisory until 4 AM PST Wednesday for Central
     Panhandle Mountains.

WA...Winter Weather Advisory until 10 AM PST Wednesday for Northeast
     Mountains.

     Winter Weather Advisory until 4 AM PST Wednesday for East Slopes
     Northern Cascades-Okanogan Highlands-Okanogan Valley.

&&

$$




000
FXUS66 KSEW 260530
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
930 PM PST TUE NOV 25 2014

.SYNOPSIS...A WARM FRONT WILL REMAIN NEAR THE CANADIAN BORDER
TONIGHT AND WEDNESDAY WITH RAIN AT TIMES OVER THE NORTH PART AND
RAIN LIKELY ELSEWHERE TONIGHT. RAIN WILL DIMINISH WITH JUST A CHANCE
OF RAIN ON WEDNESDAY. A FRONT WILL MOVE ACROSS THE AREA WEDNESDAY
NIGHT FOR MORE RAIN AND WINDY CONDITIONS. RAIN WILL CONTINUE ON
THANKSGIVING DAY AS ANOTHER COLD FRONT APPROACHES FROM THE NORTH
THEN CROSSES THE AREA THURSDAY NIGHT. COOL DRY AND BREEZY WEATHER
WILL DEVELOP BY FRIDAY AFTERNOON AND CONTINUE THROUGH THE WEEKEND AS
HIGH PRESSURE BUILDS OVER BRITISH COLUMBIA. WEAK WEATHER SYSTEMS MAY
BRING A LITTLE RAIN EARLY NEXT WEEK.

&&

.SHORT TERM...THE SURFACE WARM FRONT IS JUST NORTH OF PUGET SOUND AT
8 PM WITH SLY WINDS INCREASING S OF THE FRONT AND REMAINING MAINLY
LIGHT FROM NEAR THE E ENTRANCE TO THE N INTERIOR. ALKI WAS REPORTING
WIND GUSTS TO 43 KT THIS PAST HOUR AND OTHER OBS SITES AROUND THE
SOUND ARE GUSTY AS WELL. RAIN WILL PERSIST TO THE N OF THE FRONT SO
ANOTHER INCH OR LOCALLY 2 INCHES IS POSSIBLE TONIGHT IN THE N
CASCADES. THE WARM FRONT SHOULD LIFT N OF THE WA/B.C. BORDER BY
WEDNESDAY MORNING WITH THE BULK OF MOISTURE TO THE N OF WA. THERE
WILL BE SOME RAIN AT TIMES IN THE OLYMPICS AND AREAS N OF PUGET
SOUND AND THE CASCADES BUT AMOUNTS DO NOT LOOK HYDROLOGICALLY
SIGNIFICANT.

RAIN WILL PICK UP AGAIN WEDNESDAY NIGHT INTO THURSDAY AS A STRONG
COLD FRONT PUSHES INTO WRN WA. THE STRONG SW FLOW ALOFT WILL FAVOR
HEAVIER RAIN ALONG S/SW FACING SLOPES OF THE OLYMPICS AND N
CASCADES. 3 TO 5 INCHES OF RAIN COULD FALL RENEWING THE FLOOD THREAT
FOR THE SKOKOMISH BASIN AND ALSO PRONE RIVERS IN THE N CASCADES.
SEE THE HYDRO DISCUSSION FOR DETAILS. IT WILL ALSO RAIN ACROSS THE
LOWLANDS BUT THE STRONG SW FLOW WILL PROBABLY SHADOW PORTIONS OF
PUGET SOUND WITH LESS RAINFALL AMOUNTS EXPECTED.

MODELS HAVE TRENDED TOWARD A SECOND FRONTAL BOUNDARY HANGING UP OVER
THE AREA ON FRIDAY. THIS IS AHEAD OF A COLDER AIR MASS OVER B.C.
TRYING TO PUSH SWD. THE WLY FLOW WHICH STARTS OFF STRONG DURING THE
MORNING WILL WEAKEN CONSIDERABLY THROUGH THE DAY. THIS WILL LIMIT
OROGRAPHIC ENHANCEMENT ALONG THE CASCADES. WHILE AN INCH OR TWO IS
POSSIBLE ACROSS THE NRN PART OF THE FORECAST AREA...THE IMPACT ON
RIVERS WILL PROBABLY BE MINIMAL. WILL NEED TO LOOK OVER ALL THE 00Z
RUNS BEFORE MAKING ANY ADJUSTMENTS TO QPF.

COLDER AIR WILL BE DAMMING UP ALONG THE CANADIAN ROCKIES LATER
FRIDAY AND FRIDAY NIGHT. FRASER OUTFLOW IS EXPECTED TO DEVELOP AND
COLDER AIR ALOFT WILL ALSO START TO FILTER INTO THE AREA. SOME
MODELS SHOW RESIDUAL MOISTURE IN PLACE...LOW LEVEL CONVERGENCE...AND
COLDER AIR FILTERING IN. WILL NEED TO WATCH THIS SITUATION CLOSELY
AS THIS SET UP CAN SOMETIMES RESULT IN LOCALIZED LOWLAND SNOW. WILL
REVIEW THIS POTENTIAL FOR THE MORNING FORECAST ISSUANCE.

.LONG TERM...FROM PREVIOUS DISCUSSION...BASED ON AGREEMENT BETWEEN
THE 12Z GFS AND 12Z ECMWF SATURDAY AND SUNDAY WERE CLEARED OUT AND
THE MENTION OF RAIN DROPPED...EXCEPT FOR THE S PART LATE SUNDAY.
WITH COOL DRY N FLOW ALOFT OVER THE AREA AND COLD DRY NE FLOW FROM
THE FRASER VALLEY...SKIES WILL BE MOSTLY SUNNY...TEMPERATURES
COOL...AND N-NE WINDS BREEZY. LOWS WILL DROP INTO THE 20S SATURDAY
NIGHT WITH HIGHS SATURDAY AND SUNDAY IN THE UPPER 30S TO MID 40S.
HOWEVER...CONFIDENCE IN THE MODELS IS STILL RATHER LOW...AND THE 18Z
GFS HAS JUST REVERSED COURSE AND BRINGS RAIN UP FROM OREGON ON
SUNDAY. THE ECMWF HAS BEEN MORE CONSISTENT SO REMAINS THE PREFERRED
SOLUTION. THE ECMWF BRINGS MOISTURE AND RAIN NORTHWARD FROM OREGON
SUNDAY NIGHT.  WITH COLD AIR IN PLACE OVER W WA THERE MAY BE A
CHANCE OF SOME LIGHT SNOW...PARTICULARLY OVER THE NORTHERN ZONES AS
THE PRECIP MOVES NORTH. SO FAR THIS IS NOT ACCOUNTED FOR IN THE
FORECASTS AND WILL HAVE TO BE RE-EVALUATED ONCE MODEL CONSISTENCY
AND AGREEMENT IMPROVES. KAM

&&

.HYDROLOGY...THE AREA OF HEAVIEST RAIN IN THE CASCADES EXTENDED FROM
THE SNOQUALMIE BASIN TO THE NORTH CASCADES THIS EVENING...AND IT
CONTINUES TO SHIFT SLOWLY NORTHWARD. THE HEAVIEST RAIN FOR THE EVENT
SO FAR HAS OCCURRED IN THE MOUNT RAINIER AREA...WHERE LOCALLY UP TO
7 INCHES HAS FALLEN SINCE MONDAY AFTERNOON. THE COWLITZ... NISQUALLY
AND CARBON RIVERS ALL FLOODED. THAT AREA WILL ONLY RECEIVE ANOTHER
INCH OR SO OF RAIN TONIGHT AND WEDNESDAY. THE NISQUALLY AND CARBON
RIVERS HAVE RECEDED BELOW FLOOD STAGE...AND THE COWLITZ AT RANDLE
WILL CREST LATE THIS EVENING.

UP TO 5 INCHES OF RAIN HAS FALLEN OVER THE BASINS OF THE CENTRAL AND
NORTH CASCADES...BUT SO FAR ONLY THE SNOQUALMIE RIVER IS FLOODING.
MORE HEAVY RAIN WILL FALL IN THIS AREA TONIGHT AS THE BAROCLINIC
BAND SHIFTS NORTHWARD...WITH ANOTHER 1 TO 3 INCHES LIKELY AS THE
SNOW LEVEL REMAINS 7000 TO 8000 FT. SO OTHER RIVERS COULD STILL
FLOOD...AND IN FACT THE UPPER REACHES OF THE SNOQUALMIE AND
SKYKOMISH HAVE STARTED RISING AGAIN. IN ADDITION THE ELWHA
RIVER...FLOWING OFF THE NORTH SIDE OF THE OLYMPICS...IS RISING MORE
QUICKLY THAN EXPECTED AND IT WILL NEED WATCHING FOR THE NEXT SEVERAL
HOURS.

THE NEXT FRONTAL SYSTEM WILL BRING ANOTHER ROUND OF HEAVY RAIN
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...RENEWING THE POSSIBILITY OF
FLOODING ON CASCADES RIVERS AND ALSO PERHAPS DRIVING THE SKOKOMISH
RIVER ABOVE FLOOD STAGE. THERE WILL PROBABLY BE 3 TO 6 INCHES OF
RAIN...WITH THE OLYMPICS AND NORTH CASCADES RECEIVING THE HEAVIEST
AMOUNTS. THE SNOW LEVEL WILL BE 5500 TO 7000 FT.   MCDONNAL

&&

.AVIATION...A WARM FRONT JUST NORTH OF PUGET SOUND WILL LIFT TOWARD
THE B.C. BORDER BY WEDNESDAY MORNING. STRONG SW FLOW ALOFT WILL
PERSIST THROUGH WEDNESDAY. STABLE AND MOIST CONDITIONS WILL PERSIST
BUT RAIN WILL BECOME MORE SPOTTY IN NATURE. A FRONT WILL PUSH INTO
WRN WA WEDNESDAY NIGHT.

IFR CEILINGS AND VISIBILITIES HAVE BEEN STUBBORN TO IMPROVE NORTH OF
THE FRONT...BUT AFTER THE FRONT PASSES CEILINGS SHOULD LIFT TO LOW
END MVFR AT LEAST...1-2K FT...AND VISIBILITIES WILL IMPROVE TO 4-6SM
BR. LIGHT WINDS AT THE SURFACE WILL INCREASE TONIGHT BEHIND THE
FRONT.

KSEA...MVFR CONDITIONS LIKELY THROUGH SUNDAY WITH LITTLE RAINFALL
EXPECTED DUE TO SHADOWING OFF THE OLYMPICS. SW WINDS 15-20 KT W/
GUSTS 30 KT...EASING TO 10 KT ON WEDNESDAY.

&&

.MARINE...A FRONT NORTH OF PUGET SOUND WILL MOVE INTO SOUTHERN
BRITISH COLUMBIA BY WEDNESDAY MORNING. SMALL CRAFT ADVISORY STRENGTH
WINDS WILL SPREAD NORTH BEHIND THE FRONT...EXCEPT GALE FORCE WINDS
IN PUGET SOUND.

WINDS WILL INCREASE WEDNESDAY AS A COLD FRONT APPROACHES THE COAST.
AT LEAST SMALL CRAFT ADVISORY LEVEL WINDS ARE LIKELY OVER MOST
WATERS WITH GALES POSSIBLE ON THE COAST AND OVER EXPOSED INLAND
AREAS WEDNESDAY NIGHT. A GALE WATCH IS IN EFFECT FOR THE COAST...THE
STRAIT ENTRANCES...AND THE NORTHERN INLAND WATERS WEDNESDAY NIGHT.

ANOTHER COLD FRONT WILL MOVE THROUGH THE WATERS ON FRIDAY. THIS
FRONT WILL BE FOLLOWED BY STRONG FRASER OUTFLOW IN THE NORTHERN
INLAND WATERS AND MODERATE NORTHERLY WINDS OVER THE OTHER WATERS
LATER FRIDAY INTO SATURDAY. CHB/MERCER

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...VARIOUS FLOOD WATCHES AND WARNINGS IN EFFECT FOR PORTIONS OF
     WESTERN WASHINGTON.
PZ...GALE WARNING FOR PUGET SOUND THROUGH 6 AM WEDNESDAY MORNING.
     SMALL CRAFT ADVISORY ALL WATERS EXCEPT EAST ENTRANCE AND PUGET
     SOUND.
     SMALL CRAFT ADVISORY FOR ROUGH GRAYS HARBOR BAR.
     GALE WATCH COAST...ENTRANCES...AND NORTHERN INLAND WATERS
     WEDNESDAY NIGHT.

&&

$$

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















000
FXUS66 KSEW 260530
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
930 PM PST TUE NOV 25 2014

.SYNOPSIS...A WARM FRONT WILL REMAIN NEAR THE CANADIAN BORDER
TONIGHT AND WEDNESDAY WITH RAIN AT TIMES OVER THE NORTH PART AND
RAIN LIKELY ELSEWHERE TONIGHT. RAIN WILL DIMINISH WITH JUST A CHANCE
OF RAIN ON WEDNESDAY. A FRONT WILL MOVE ACROSS THE AREA WEDNESDAY
NIGHT FOR MORE RAIN AND WINDY CONDITIONS. RAIN WILL CONTINUE ON
THANKSGIVING DAY AS ANOTHER COLD FRONT APPROACHES FROM THE NORTH
THEN CROSSES THE AREA THURSDAY NIGHT. COOL DRY AND BREEZY WEATHER
WILL DEVELOP BY FRIDAY AFTERNOON AND CONTINUE THROUGH THE WEEKEND AS
HIGH PRESSURE BUILDS OVER BRITISH COLUMBIA. WEAK WEATHER SYSTEMS MAY
BRING A LITTLE RAIN EARLY NEXT WEEK.

&&

.SHORT TERM...THE SURFACE WARM FRONT IS JUST NORTH OF PUGET SOUND AT
8 PM WITH SLY WINDS INCREASING S OF THE FRONT AND REMAINING MAINLY
LIGHT FROM NEAR THE E ENTRANCE TO THE N INTERIOR. ALKI WAS REPORTING
WIND GUSTS TO 43 KT THIS PAST HOUR AND OTHER OBS SITES AROUND THE
SOUND ARE GUSTY AS WELL. RAIN WILL PERSIST TO THE N OF THE FRONT SO
ANOTHER INCH OR LOCALLY 2 INCHES IS POSSIBLE TONIGHT IN THE N
CASCADES. THE WARM FRONT SHOULD LIFT N OF THE WA/B.C. BORDER BY
WEDNESDAY MORNING WITH THE BULK OF MOISTURE TO THE N OF WA. THERE
WILL BE SOME RAIN AT TIMES IN THE OLYMPICS AND AREAS N OF PUGET
SOUND AND THE CASCADES BUT AMOUNTS DO NOT LOOK HYDROLOGICALLY
SIGNIFICANT.

RAIN WILL PICK UP AGAIN WEDNESDAY NIGHT INTO THURSDAY AS A STRONG
COLD FRONT PUSHES INTO WRN WA. THE STRONG SW FLOW ALOFT WILL FAVOR
HEAVIER RAIN ALONG S/SW FACING SLOPES OF THE OLYMPICS AND N
CASCADES. 3 TO 5 INCHES OF RAIN COULD FALL RENEWING THE FLOOD THREAT
FOR THE SKOKOMISH BASIN AND ALSO PRONE RIVERS IN THE N CASCADES.
SEE THE HYDRO DISCUSSION FOR DETAILS. IT WILL ALSO RAIN ACROSS THE
LOWLANDS BUT THE STRONG SW FLOW WILL PROBABLY SHADOW PORTIONS OF
PUGET SOUND WITH LESS RAINFALL AMOUNTS EXPECTED.

MODELS HAVE TRENDED TOWARD A SECOND FRONTAL BOUNDARY HANGING UP OVER
THE AREA ON FRIDAY. THIS IS AHEAD OF A COLDER AIR MASS OVER B.C.
TRYING TO PUSH SWD. THE WLY FLOW WHICH STARTS OFF STRONG DURING THE
MORNING WILL WEAKEN CONSIDERABLY THROUGH THE DAY. THIS WILL LIMIT
OROGRAPHIC ENHANCEMENT ALONG THE CASCADES. WHILE AN INCH OR TWO IS
POSSIBLE ACROSS THE NRN PART OF THE FORECAST AREA...THE IMPACT ON
RIVERS WILL PROBABLY BE MINIMAL. WILL NEED TO LOOK OVER ALL THE 00Z
RUNS BEFORE MAKING ANY ADJUSTMENTS TO QPF.

COLDER AIR WILL BE DAMMING UP ALONG THE CANADIAN ROCKIES LATER
FRIDAY AND FRIDAY NIGHT. FRASER OUTFLOW IS EXPECTED TO DEVELOP AND
COLDER AIR ALOFT WILL ALSO START TO FILTER INTO THE AREA. SOME
MODELS SHOW RESIDUAL MOISTURE IN PLACE...LOW LEVEL CONVERGENCE...AND
COLDER AIR FILTERING IN. WILL NEED TO WATCH THIS SITUATION CLOSELY
AS THIS SET UP CAN SOMETIMES RESULT IN LOCALIZED LOWLAND SNOW. WILL
REVIEW THIS POTENTIAL FOR THE MORNING FORECAST ISSUANCE.

.LONG TERM...FROM PREVIOUS DISCUSSION...BASED ON AGREEMENT BETWEEN
THE 12Z GFS AND 12Z ECMWF SATURDAY AND SUNDAY WERE CLEARED OUT AND
THE MENTION OF RAIN DROPPED...EXCEPT FOR THE S PART LATE SUNDAY.
WITH COOL DRY N FLOW ALOFT OVER THE AREA AND COLD DRY NE FLOW FROM
THE FRASER VALLEY...SKIES WILL BE MOSTLY SUNNY...TEMPERATURES
COOL...AND N-NE WINDS BREEZY. LOWS WILL DROP INTO THE 20S SATURDAY
NIGHT WITH HIGHS SATURDAY AND SUNDAY IN THE UPPER 30S TO MID 40S.
HOWEVER...CONFIDENCE IN THE MODELS IS STILL RATHER LOW...AND THE 18Z
GFS HAS JUST REVERSED COURSE AND BRINGS RAIN UP FROM OREGON ON
SUNDAY. THE ECMWF HAS BEEN MORE CONSISTENT SO REMAINS THE PREFERRED
SOLUTION. THE ECMWF BRINGS MOISTURE AND RAIN NORTHWARD FROM OREGON
SUNDAY NIGHT.  WITH COLD AIR IN PLACE OVER W WA THERE MAY BE A
CHANCE OF SOME LIGHT SNOW...PARTICULARLY OVER THE NORTHERN ZONES AS
THE PRECIP MOVES NORTH. SO FAR THIS IS NOT ACCOUNTED FOR IN THE
FORECASTS AND WILL HAVE TO BE RE-EVALUATED ONCE MODEL CONSISTENCY
AND AGREEMENT IMPROVES. KAM

&&

.HYDROLOGY...THE AREA OF HEAVIEST RAIN IN THE CASCADES EXTENDED FROM
THE SNOQUALMIE BASIN TO THE NORTH CASCADES THIS EVENING...AND IT
CONTINUES TO SHIFT SLOWLY NORTHWARD. THE HEAVIEST RAIN FOR THE EVENT
SO FAR HAS OCCURRED IN THE MOUNT RAINIER AREA...WHERE LOCALLY UP TO
7 INCHES HAS FALLEN SINCE MONDAY AFTERNOON. THE COWLITZ... NISQUALLY
AND CARBON RIVERS ALL FLOODED. THAT AREA WILL ONLY RECEIVE ANOTHER
INCH OR SO OF RAIN TONIGHT AND WEDNESDAY. THE NISQUALLY AND CARBON
RIVERS HAVE RECEDED BELOW FLOOD STAGE...AND THE COWLITZ AT RANDLE
WILL CREST LATE THIS EVENING.

UP TO 5 INCHES OF RAIN HAS FALLEN OVER THE BASINS OF THE CENTRAL AND
NORTH CASCADES...BUT SO FAR ONLY THE SNOQUALMIE RIVER IS FLOODING.
MORE HEAVY RAIN WILL FALL IN THIS AREA TONIGHT AS THE BAROCLINIC
BAND SHIFTS NORTHWARD...WITH ANOTHER 1 TO 3 INCHES LIKELY AS THE
SNOW LEVEL REMAINS 7000 TO 8000 FT. SO OTHER RIVERS COULD STILL
FLOOD...AND IN FACT THE UPPER REACHES OF THE SNOQUALMIE AND
SKYKOMISH HAVE STARTED RISING AGAIN. IN ADDITION THE ELWHA
RIVER...FLOWING OFF THE NORTH SIDE OF THE OLYMPICS...IS RISING MORE
QUICKLY THAN EXPECTED AND IT WILL NEED WATCHING FOR THE NEXT SEVERAL
HOURS.

THE NEXT FRONTAL SYSTEM WILL BRING ANOTHER ROUND OF HEAVY RAIN
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...RENEWING THE POSSIBILITY OF
FLOODING ON CASCADES RIVERS AND ALSO PERHAPS DRIVING THE SKOKOMISH
RIVER ABOVE FLOOD STAGE. THERE WILL PROBABLY BE 3 TO 6 INCHES OF
RAIN...WITH THE OLYMPICS AND NORTH CASCADES RECEIVING THE HEAVIEST
AMOUNTS. THE SNOW LEVEL WILL BE 5500 TO 7000 FT.   MCDONNAL

&&

.AVIATION...A WARM FRONT JUST NORTH OF PUGET SOUND WILL LIFT TOWARD
THE B.C. BORDER BY WEDNESDAY MORNING. STRONG SW FLOW ALOFT WILL
PERSIST THROUGH WEDNESDAY. STABLE AND MOIST CONDITIONS WILL PERSIST
BUT RAIN WILL BECOME MORE SPOTTY IN NATURE. A FRONT WILL PUSH INTO
WRN WA WEDNESDAY NIGHT.

IFR CEILINGS AND VISIBILITIES HAVE BEEN STUBBORN TO IMPROVE NORTH OF
THE FRONT...BUT AFTER THE FRONT PASSES CEILINGS SHOULD LIFT TO LOW
END MVFR AT LEAST...1-2K FT...AND VISIBILITIES WILL IMPROVE TO 4-6SM
BR. LIGHT WINDS AT THE SURFACE WILL INCREASE TONIGHT BEHIND THE
FRONT.

KSEA...MVFR CONDITIONS LIKELY THROUGH SUNDAY WITH LITTLE RAINFALL
EXPECTED DUE TO SHADOWING OFF THE OLYMPICS. SW WINDS 15-20 KT W/
GUSTS 30 KT...EASING TO 10 KT ON WEDNESDAY.

&&

.MARINE...A FRONT NORTH OF PUGET SOUND WILL MOVE INTO SOUTHERN
BRITISH COLUMBIA BY WEDNESDAY MORNING. SMALL CRAFT ADVISORY STRENGTH
WINDS WILL SPREAD NORTH BEHIND THE FRONT...EXCEPT GALE FORCE WINDS
IN PUGET SOUND.

WINDS WILL INCREASE WEDNESDAY AS A COLD FRONT APPROACHES THE COAST.
AT LEAST SMALL CRAFT ADVISORY LEVEL WINDS ARE LIKELY OVER MOST
WATERS WITH GALES POSSIBLE ON THE COAST AND OVER EXPOSED INLAND
AREAS WEDNESDAY NIGHT. A GALE WATCH IS IN EFFECT FOR THE COAST...THE
STRAIT ENTRANCES...AND THE NORTHERN INLAND WATERS WEDNESDAY NIGHT.

ANOTHER COLD FRONT WILL MOVE THROUGH THE WATERS ON FRIDAY. THIS
FRONT WILL BE FOLLOWED BY STRONG FRASER OUTFLOW IN THE NORTHERN
INLAND WATERS AND MODERATE NORTHERLY WINDS OVER THE OTHER WATERS
LATER FRIDAY INTO SATURDAY. CHB/MERCER

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...VARIOUS FLOOD WATCHES AND WARNINGS IN EFFECT FOR PORTIONS OF
     WESTERN WASHINGTON.
PZ...GALE WARNING FOR PUGET SOUND THROUGH 6 AM WEDNESDAY MORNING.
     SMALL CRAFT ADVISORY ALL WATERS EXCEPT EAST ENTRANCE AND PUGET
     SOUND.
     SMALL CRAFT ADVISORY FOR ROUGH GRAYS HARBOR BAR.
     GALE WATCH COAST...ENTRANCES...AND NORTHERN INLAND WATERS
     WEDNESDAY NIGHT.

&&

$$

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















000
FXUS66 KSEW 260530
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
930 PM PST TUE NOV 25 2014

.SYNOPSIS...A WARM FRONT WILL REMAIN NEAR THE CANADIAN BORDER
TONIGHT AND WEDNESDAY WITH RAIN AT TIMES OVER THE NORTH PART AND
RAIN LIKELY ELSEWHERE TONIGHT. RAIN WILL DIMINISH WITH JUST A CHANCE
OF RAIN ON WEDNESDAY. A FRONT WILL MOVE ACROSS THE AREA WEDNESDAY
NIGHT FOR MORE RAIN AND WINDY CONDITIONS. RAIN WILL CONTINUE ON
THANKSGIVING DAY AS ANOTHER COLD FRONT APPROACHES FROM THE NORTH
THEN CROSSES THE AREA THURSDAY NIGHT. COOL DRY AND BREEZY WEATHER
WILL DEVELOP BY FRIDAY AFTERNOON AND CONTINUE THROUGH THE WEEKEND AS
HIGH PRESSURE BUILDS OVER BRITISH COLUMBIA. WEAK WEATHER SYSTEMS MAY
BRING A LITTLE RAIN EARLY NEXT WEEK.

&&

.SHORT TERM...THE SURFACE WARM FRONT IS JUST NORTH OF PUGET SOUND AT
8 PM WITH SLY WINDS INCREASING S OF THE FRONT AND REMAINING MAINLY
LIGHT FROM NEAR THE E ENTRANCE TO THE N INTERIOR. ALKI WAS REPORTING
WIND GUSTS TO 43 KT THIS PAST HOUR AND OTHER OBS SITES AROUND THE
SOUND ARE GUSTY AS WELL. RAIN WILL PERSIST TO THE N OF THE FRONT SO
ANOTHER INCH OR LOCALLY 2 INCHES IS POSSIBLE TONIGHT IN THE N
CASCADES. THE WARM FRONT SHOULD LIFT N OF THE WA/B.C. BORDER BY
WEDNESDAY MORNING WITH THE BULK OF MOISTURE TO THE N OF WA. THERE
WILL BE SOME RAIN AT TIMES IN THE OLYMPICS AND AREAS N OF PUGET
SOUND AND THE CASCADES BUT AMOUNTS DO NOT LOOK HYDROLOGICALLY
SIGNIFICANT.

RAIN WILL PICK UP AGAIN WEDNESDAY NIGHT INTO THURSDAY AS A STRONG
COLD FRONT PUSHES INTO WRN WA. THE STRONG SW FLOW ALOFT WILL FAVOR
HEAVIER RAIN ALONG S/SW FACING SLOPES OF THE OLYMPICS AND N
CASCADES. 3 TO 5 INCHES OF RAIN COULD FALL RENEWING THE FLOOD THREAT
FOR THE SKOKOMISH BASIN AND ALSO PRONE RIVERS IN THE N CASCADES.
SEE THE HYDRO DISCUSSION FOR DETAILS. IT WILL ALSO RAIN ACROSS THE
LOWLANDS BUT THE STRONG SW FLOW WILL PROBABLY SHADOW PORTIONS OF
PUGET SOUND WITH LESS RAINFALL AMOUNTS EXPECTED.

MODELS HAVE TRENDED TOWARD A SECOND FRONTAL BOUNDARY HANGING UP OVER
THE AREA ON FRIDAY. THIS IS AHEAD OF A COLDER AIR MASS OVER B.C.
TRYING TO PUSH SWD. THE WLY FLOW WHICH STARTS OFF STRONG DURING THE
MORNING WILL WEAKEN CONSIDERABLY THROUGH THE DAY. THIS WILL LIMIT
OROGRAPHIC ENHANCEMENT ALONG THE CASCADES. WHILE AN INCH OR TWO IS
POSSIBLE ACROSS THE NRN PART OF THE FORECAST AREA...THE IMPACT ON
RIVERS WILL PROBABLY BE MINIMAL. WILL NEED TO LOOK OVER ALL THE 00Z
RUNS BEFORE MAKING ANY ADJUSTMENTS TO QPF.

COLDER AIR WILL BE DAMMING UP ALONG THE CANADIAN ROCKIES LATER
FRIDAY AND FRIDAY NIGHT. FRASER OUTFLOW IS EXPECTED TO DEVELOP AND
COLDER AIR ALOFT WILL ALSO START TO FILTER INTO THE AREA. SOME
MODELS SHOW RESIDUAL MOISTURE IN PLACE...LOW LEVEL CONVERGENCE...AND
COLDER AIR FILTERING IN. WILL NEED TO WATCH THIS SITUATION CLOSELY
AS THIS SET UP CAN SOMETIMES RESULT IN LOCALIZED LOWLAND SNOW. WILL
REVIEW THIS POTENTIAL FOR THE MORNING FORECAST ISSUANCE.

.LONG TERM...FROM PREVIOUS DISCUSSION...BASED ON AGREEMENT BETWEEN
THE 12Z GFS AND 12Z ECMWF SATURDAY AND SUNDAY WERE CLEARED OUT AND
THE MENTION OF RAIN DROPPED...EXCEPT FOR THE S PART LATE SUNDAY.
WITH COOL DRY N FLOW ALOFT OVER THE AREA AND COLD DRY NE FLOW FROM
THE FRASER VALLEY...SKIES WILL BE MOSTLY SUNNY...TEMPERATURES
COOL...AND N-NE WINDS BREEZY. LOWS WILL DROP INTO THE 20S SATURDAY
NIGHT WITH HIGHS SATURDAY AND SUNDAY IN THE UPPER 30S TO MID 40S.
HOWEVER...CONFIDENCE IN THE MODELS IS STILL RATHER LOW...AND THE 18Z
GFS HAS JUST REVERSED COURSE AND BRINGS RAIN UP FROM OREGON ON
SUNDAY. THE ECMWF HAS BEEN MORE CONSISTENT SO REMAINS THE PREFERRED
SOLUTION. THE ECMWF BRINGS MOISTURE AND RAIN NORTHWARD FROM OREGON
SUNDAY NIGHT.  WITH COLD AIR IN PLACE OVER W WA THERE MAY BE A
CHANCE OF SOME LIGHT SNOW...PARTICULARLY OVER THE NORTHERN ZONES AS
THE PRECIP MOVES NORTH. SO FAR THIS IS NOT ACCOUNTED FOR IN THE
FORECASTS AND WILL HAVE TO BE RE-EVALUATED ONCE MODEL CONSISTENCY
AND AGREEMENT IMPROVES. KAM

&&

.HYDROLOGY...THE AREA OF HEAVIEST RAIN IN THE CASCADES EXTENDED FROM
THE SNOQUALMIE BASIN TO THE NORTH CASCADES THIS EVENING...AND IT
CONTINUES TO SHIFT SLOWLY NORTHWARD. THE HEAVIEST RAIN FOR THE EVENT
SO FAR HAS OCCURRED IN THE MOUNT RAINIER AREA...WHERE LOCALLY UP TO
7 INCHES HAS FALLEN SINCE MONDAY AFTERNOON. THE COWLITZ... NISQUALLY
AND CARBON RIVERS ALL FLOODED. THAT AREA WILL ONLY RECEIVE ANOTHER
INCH OR SO OF RAIN TONIGHT AND WEDNESDAY. THE NISQUALLY AND CARBON
RIVERS HAVE RECEDED BELOW FLOOD STAGE...AND THE COWLITZ AT RANDLE
WILL CREST LATE THIS EVENING.

UP TO 5 INCHES OF RAIN HAS FALLEN OVER THE BASINS OF THE CENTRAL AND
NORTH CASCADES...BUT SO FAR ONLY THE SNOQUALMIE RIVER IS FLOODING.
MORE HEAVY RAIN WILL FALL IN THIS AREA TONIGHT AS THE BAROCLINIC
BAND SHIFTS NORTHWARD...WITH ANOTHER 1 TO 3 INCHES LIKELY AS THE
SNOW LEVEL REMAINS 7000 TO 8000 FT. SO OTHER RIVERS COULD STILL
FLOOD...AND IN FACT THE UPPER REACHES OF THE SNOQUALMIE AND
SKYKOMISH HAVE STARTED RISING AGAIN. IN ADDITION THE ELWHA
RIVER...FLOWING OFF THE NORTH SIDE OF THE OLYMPICS...IS RISING MORE
QUICKLY THAN EXPECTED AND IT WILL NEED WATCHING FOR THE NEXT SEVERAL
HOURS.

THE NEXT FRONTAL SYSTEM WILL BRING ANOTHER ROUND OF HEAVY RAIN
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...RENEWING THE POSSIBILITY OF
FLOODING ON CASCADES RIVERS AND ALSO PERHAPS DRIVING THE SKOKOMISH
RIVER ABOVE FLOOD STAGE. THERE WILL PROBABLY BE 3 TO 6 INCHES OF
RAIN...WITH THE OLYMPICS AND NORTH CASCADES RECEIVING THE HEAVIEST
AMOUNTS. THE SNOW LEVEL WILL BE 5500 TO 7000 FT.   MCDONNAL

&&

.AVIATION...A WARM FRONT JUST NORTH OF PUGET SOUND WILL LIFT TOWARD
THE B.C. BORDER BY WEDNESDAY MORNING. STRONG SW FLOW ALOFT WILL
PERSIST THROUGH WEDNESDAY. STABLE AND MOIST CONDITIONS WILL PERSIST
BUT RAIN WILL BECOME MORE SPOTTY IN NATURE. A FRONT WILL PUSH INTO
WRN WA WEDNESDAY NIGHT.

IFR CEILINGS AND VISIBILITIES HAVE BEEN STUBBORN TO IMPROVE NORTH OF
THE FRONT...BUT AFTER THE FRONT PASSES CEILINGS SHOULD LIFT TO LOW
END MVFR AT LEAST...1-2K FT...AND VISIBILITIES WILL IMPROVE TO 4-6SM
BR. LIGHT WINDS AT THE SURFACE WILL INCREASE TONIGHT BEHIND THE
FRONT.

KSEA...MVFR CONDITIONS LIKELY THROUGH SUNDAY WITH LITTLE RAINFALL
EXPECTED DUE TO SHADOWING OFF THE OLYMPICS. SW WINDS 15-20 KT W/
GUSTS 30 KT...EASING TO 10 KT ON WEDNESDAY.

&&

.MARINE...A FRONT NORTH OF PUGET SOUND WILL MOVE INTO SOUTHERN
BRITISH COLUMBIA BY WEDNESDAY MORNING. SMALL CRAFT ADVISORY STRENGTH
WINDS WILL SPREAD NORTH BEHIND THE FRONT...EXCEPT GALE FORCE WINDS
IN PUGET SOUND.

WINDS WILL INCREASE WEDNESDAY AS A COLD FRONT APPROACHES THE COAST.
AT LEAST SMALL CRAFT ADVISORY LEVEL WINDS ARE LIKELY OVER MOST
WATERS WITH GALES POSSIBLE ON THE COAST AND OVER EXPOSED INLAND
AREAS WEDNESDAY NIGHT. A GALE WATCH IS IN EFFECT FOR THE COAST...THE
STRAIT ENTRANCES...AND THE NORTHERN INLAND WATERS WEDNESDAY NIGHT.

ANOTHER COLD FRONT WILL MOVE THROUGH THE WATERS ON FRIDAY. THIS
FRONT WILL BE FOLLOWED BY STRONG FRASER OUTFLOW IN THE NORTHERN
INLAND WATERS AND MODERATE NORTHERLY WINDS OVER THE OTHER WATERS
LATER FRIDAY INTO SATURDAY. CHB/MERCER

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...VARIOUS FLOOD WATCHES AND WARNINGS IN EFFECT FOR PORTIONS OF
     WESTERN WASHINGTON.
PZ...GALE WARNING FOR PUGET SOUND THROUGH 6 AM WEDNESDAY MORNING.
     SMALL CRAFT ADVISORY ALL WATERS EXCEPT EAST ENTRANCE AND PUGET
     SOUND.
     SMALL CRAFT ADVISORY FOR ROUGH GRAYS HARBOR BAR.
     GALE WATCH COAST...ENTRANCES...AND NORTHERN INLAND WATERS
     WEDNESDAY NIGHT.

&&

$$

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















000
FXUS66 KSEW 260530
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
930 PM PST TUE NOV 25 2014

.SYNOPSIS...A WARM FRONT WILL REMAIN NEAR THE CANADIAN BORDER
TONIGHT AND WEDNESDAY WITH RAIN AT TIMES OVER THE NORTH PART AND
RAIN LIKELY ELSEWHERE TONIGHT. RAIN WILL DIMINISH WITH JUST A CHANCE
OF RAIN ON WEDNESDAY. A FRONT WILL MOVE ACROSS THE AREA WEDNESDAY
NIGHT FOR MORE RAIN AND WINDY CONDITIONS. RAIN WILL CONTINUE ON
THANKSGIVING DAY AS ANOTHER COLD FRONT APPROACHES FROM THE NORTH
THEN CROSSES THE AREA THURSDAY NIGHT. COOL DRY AND BREEZY WEATHER
WILL DEVELOP BY FRIDAY AFTERNOON AND CONTINUE THROUGH THE WEEKEND AS
HIGH PRESSURE BUILDS OVER BRITISH COLUMBIA. WEAK WEATHER SYSTEMS MAY
BRING A LITTLE RAIN EARLY NEXT WEEK.

&&

.SHORT TERM...THE SURFACE WARM FRONT IS JUST NORTH OF PUGET SOUND AT
8 PM WITH SLY WINDS INCREASING S OF THE FRONT AND REMAINING MAINLY
LIGHT FROM NEAR THE E ENTRANCE TO THE N INTERIOR. ALKI WAS REPORTING
WIND GUSTS TO 43 KT THIS PAST HOUR AND OTHER OBS SITES AROUND THE
SOUND ARE GUSTY AS WELL. RAIN WILL PERSIST TO THE N OF THE FRONT SO
ANOTHER INCH OR LOCALLY 2 INCHES IS POSSIBLE TONIGHT IN THE N
CASCADES. THE WARM FRONT SHOULD LIFT N OF THE WA/B.C. BORDER BY
WEDNESDAY MORNING WITH THE BULK OF MOISTURE TO THE N OF WA. THERE
WILL BE SOME RAIN AT TIMES IN THE OLYMPICS AND AREAS N OF PUGET
SOUND AND THE CASCADES BUT AMOUNTS DO NOT LOOK HYDROLOGICALLY
SIGNIFICANT.

RAIN WILL PICK UP AGAIN WEDNESDAY NIGHT INTO THURSDAY AS A STRONG
COLD FRONT PUSHES INTO WRN WA. THE STRONG SW FLOW ALOFT WILL FAVOR
HEAVIER RAIN ALONG S/SW FACING SLOPES OF THE OLYMPICS AND N
CASCADES. 3 TO 5 INCHES OF RAIN COULD FALL RENEWING THE FLOOD THREAT
FOR THE SKOKOMISH BASIN AND ALSO PRONE RIVERS IN THE N CASCADES.
SEE THE HYDRO DISCUSSION FOR DETAILS. IT WILL ALSO RAIN ACROSS THE
LOWLANDS BUT THE STRONG SW FLOW WILL PROBABLY SHADOW PORTIONS OF
PUGET SOUND WITH LESS RAINFALL AMOUNTS EXPECTED.

MODELS HAVE TRENDED TOWARD A SECOND FRONTAL BOUNDARY HANGING UP OVER
THE AREA ON FRIDAY. THIS IS AHEAD OF A COLDER AIR MASS OVER B.C.
TRYING TO PUSH SWD. THE WLY FLOW WHICH STARTS OFF STRONG DURING THE
MORNING WILL WEAKEN CONSIDERABLY THROUGH THE DAY. THIS WILL LIMIT
OROGRAPHIC ENHANCEMENT ALONG THE CASCADES. WHILE AN INCH OR TWO IS
POSSIBLE ACROSS THE NRN PART OF THE FORECAST AREA...THE IMPACT ON
RIVERS WILL PROBABLY BE MINIMAL. WILL NEED TO LOOK OVER ALL THE 00Z
RUNS BEFORE MAKING ANY ADJUSTMENTS TO QPF.

COLDER AIR WILL BE DAMMING UP ALONG THE CANADIAN ROCKIES LATER
FRIDAY AND FRIDAY NIGHT. FRASER OUTFLOW IS EXPECTED TO DEVELOP AND
COLDER AIR ALOFT WILL ALSO START TO FILTER INTO THE AREA. SOME
MODELS SHOW RESIDUAL MOISTURE IN PLACE...LOW LEVEL CONVERGENCE...AND
COLDER AIR FILTERING IN. WILL NEED TO WATCH THIS SITUATION CLOSELY
AS THIS SET UP CAN SOMETIMES RESULT IN LOCALIZED LOWLAND SNOW. WILL
REVIEW THIS POTENTIAL FOR THE MORNING FORECAST ISSUANCE.

.LONG TERM...FROM PREVIOUS DISCUSSION...BASED ON AGREEMENT BETWEEN
THE 12Z GFS AND 12Z ECMWF SATURDAY AND SUNDAY WERE CLEARED OUT AND
THE MENTION OF RAIN DROPPED...EXCEPT FOR THE S PART LATE SUNDAY.
WITH COOL DRY N FLOW ALOFT OVER THE AREA AND COLD DRY NE FLOW FROM
THE FRASER VALLEY...SKIES WILL BE MOSTLY SUNNY...TEMPERATURES
COOL...AND N-NE WINDS BREEZY. LOWS WILL DROP INTO THE 20S SATURDAY
NIGHT WITH HIGHS SATURDAY AND SUNDAY IN THE UPPER 30S TO MID 40S.
HOWEVER...CONFIDENCE IN THE MODELS IS STILL RATHER LOW...AND THE 18Z
GFS HAS JUST REVERSED COURSE AND BRINGS RAIN UP FROM OREGON ON
SUNDAY. THE ECMWF HAS BEEN MORE CONSISTENT SO REMAINS THE PREFERRED
SOLUTION. THE ECMWF BRINGS MOISTURE AND RAIN NORTHWARD FROM OREGON
SUNDAY NIGHT.  WITH COLD AIR IN PLACE OVER W WA THERE MAY BE A
CHANCE OF SOME LIGHT SNOW...PARTICULARLY OVER THE NORTHERN ZONES AS
THE PRECIP MOVES NORTH. SO FAR THIS IS NOT ACCOUNTED FOR IN THE
FORECASTS AND WILL HAVE TO BE RE-EVALUATED ONCE MODEL CONSISTENCY
AND AGREEMENT IMPROVES. KAM

&&

.HYDROLOGY...THE AREA OF HEAVIEST RAIN IN THE CASCADES EXTENDED FROM
THE SNOQUALMIE BASIN TO THE NORTH CASCADES THIS EVENING...AND IT
CONTINUES TO SHIFT SLOWLY NORTHWARD. THE HEAVIEST RAIN FOR THE EVENT
SO FAR HAS OCCURRED IN THE MOUNT RAINIER AREA...WHERE LOCALLY UP TO
7 INCHES HAS FALLEN SINCE MONDAY AFTERNOON. THE COWLITZ... NISQUALLY
AND CARBON RIVERS ALL FLOODED. THAT AREA WILL ONLY RECEIVE ANOTHER
INCH OR SO OF RAIN TONIGHT AND WEDNESDAY. THE NISQUALLY AND CARBON
RIVERS HAVE RECEDED BELOW FLOOD STAGE...AND THE COWLITZ AT RANDLE
WILL CREST LATE THIS EVENING.

UP TO 5 INCHES OF RAIN HAS FALLEN OVER THE BASINS OF THE CENTRAL AND
NORTH CASCADES...BUT SO FAR ONLY THE SNOQUALMIE RIVER IS FLOODING.
MORE HEAVY RAIN WILL FALL IN THIS AREA TONIGHT AS THE BAROCLINIC
BAND SHIFTS NORTHWARD...WITH ANOTHER 1 TO 3 INCHES LIKELY AS THE
SNOW LEVEL REMAINS 7000 TO 8000 FT. SO OTHER RIVERS COULD STILL
FLOOD...AND IN FACT THE UPPER REACHES OF THE SNOQUALMIE AND
SKYKOMISH HAVE STARTED RISING AGAIN. IN ADDITION THE ELWHA
RIVER...FLOWING OFF THE NORTH SIDE OF THE OLYMPICS...IS RISING MORE
QUICKLY THAN EXPECTED AND IT WILL NEED WATCHING FOR THE NEXT SEVERAL
HOURS.

THE NEXT FRONTAL SYSTEM WILL BRING ANOTHER ROUND OF HEAVY RAIN
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...RENEWING THE POSSIBILITY OF
FLOODING ON CASCADES RIVERS AND ALSO PERHAPS DRIVING THE SKOKOMISH
RIVER ABOVE FLOOD STAGE. THERE WILL PROBABLY BE 3 TO 6 INCHES OF
RAIN...WITH THE OLYMPICS AND NORTH CASCADES RECEIVING THE HEAVIEST
AMOUNTS. THE SNOW LEVEL WILL BE 5500 TO 7000 FT.   MCDONNAL

&&

.AVIATION...A WARM FRONT JUST NORTH OF PUGET SOUND WILL LIFT TOWARD
THE B.C. BORDER BY WEDNESDAY MORNING. STRONG SW FLOW ALOFT WILL
PERSIST THROUGH WEDNESDAY. STABLE AND MOIST CONDITIONS WILL PERSIST
BUT RAIN WILL BECOME MORE SPOTTY IN NATURE. A FRONT WILL PUSH INTO
WRN WA WEDNESDAY NIGHT.

IFR CEILINGS AND VISIBILITIES HAVE BEEN STUBBORN TO IMPROVE NORTH OF
THE FRONT...BUT AFTER THE FRONT PASSES CEILINGS SHOULD LIFT TO LOW
END MVFR AT LEAST...1-2K FT...AND VISIBILITIES WILL IMPROVE TO 4-6SM
BR. LIGHT WINDS AT THE SURFACE WILL INCREASE TONIGHT BEHIND THE
FRONT.

KSEA...MVFR CONDITIONS LIKELY THROUGH SUNDAY WITH LITTLE RAINFALL
EXPECTED DUE TO SHADOWING OFF THE OLYMPICS. SW WINDS 15-20 KT W/
GUSTS 30 KT...EASING TO 10 KT ON WEDNESDAY.

&&

.MARINE...A FRONT NORTH OF PUGET SOUND WILL MOVE INTO SOUTHERN
BRITISH COLUMBIA BY WEDNESDAY MORNING. SMALL CRAFT ADVISORY STRENGTH
WINDS WILL SPREAD NORTH BEHIND THE FRONT...EXCEPT GALE FORCE WINDS
IN PUGET SOUND.

WINDS WILL INCREASE WEDNESDAY AS A COLD FRONT APPROACHES THE COAST.
AT LEAST SMALL CRAFT ADVISORY LEVEL WINDS ARE LIKELY OVER MOST
WATERS WITH GALES POSSIBLE ON THE COAST AND OVER EXPOSED INLAND
AREAS WEDNESDAY NIGHT. A GALE WATCH IS IN EFFECT FOR THE COAST...THE
STRAIT ENTRANCES...AND THE NORTHERN INLAND WATERS WEDNESDAY NIGHT.

ANOTHER COLD FRONT WILL MOVE THROUGH THE WATERS ON FRIDAY. THIS
FRONT WILL BE FOLLOWED BY STRONG FRASER OUTFLOW IN THE NORTHERN
INLAND WATERS AND MODERATE NORTHERLY WINDS OVER THE OTHER WATERS
LATER FRIDAY INTO SATURDAY. CHB/MERCER

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...VARIOUS FLOOD WATCHES AND WARNINGS IN EFFECT FOR PORTIONS OF
     WESTERN WASHINGTON.
PZ...GALE WARNING FOR PUGET SOUND THROUGH 6 AM WEDNESDAY MORNING.
     SMALL CRAFT ADVISORY ALL WATERS EXCEPT EAST ENTRANCE AND PUGET
     SOUND.
     SMALL CRAFT ADVISORY FOR ROUGH GRAYS HARBOR BAR.
     GALE WATCH COAST...ENTRANCES...AND NORTHERN INLAND WATERS
     WEDNESDAY NIGHT.

&&

$$

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















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