000
FXUS66 KPQR 200338
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
837 PM PDT SUN MAY 19 2013
.SYNOPSIS...MILD LATE SPRING WEATHER CONTINUES THROUGH MON. THEN BIG
CHANGES AS A STRONG COLD FRONT SWEEPS ACROSS THE REGION TUE. THIS
WILL BRING MUCH COOLER AND UNSETTLED WEATHER THAT WILL LINGER THROUGH
THEN END OF THE WEEK.
&&
.SHORT TERM...ONSHORE FLOW TURNING A BIT MORE NORTHERLY THIS EVENING.
THIS ALLOWING FOR LARGE AREAS OF CLEARING. NOT MUCH CHANGE OVERNIGHT
AS WILL SEE MOSTLY CLEAR TO PARTLY CLOUDY SKIES.
VERY PLEASANT DAY ON MON...AS HIGH PRES OVER THE REGION BUILDS. AIR
MASS WARMS IN RESPONSE TO THE HIGH...WITH 850 MB TEMPS RUNNING ABOUT
5 TO 8 DEG C ABOVE THOSE ON SUNDAY. WITH PLENTY OF SUNSHINE...THIS
PUTS MONDAY AFTERNOON TEMPS WELL INTO THE 70S FOR INTERIOR...BUT
STAYING COOLER ALONG THE COAST WITH LOWER 60S.
ALL EYES STARTING SHIFTING FURTHER WEST LATER MON AND MON NIGHT...AS
A DEVELOPING LOW THAT IS NOW NEAR 140W AND 47N WILL DRAW CLOSER.
PLENTY OF COLD AIR BEHIND THE FRONT WILL BRING MAJOR CHANGES FOR THE
PAC NW. THE COLD FRONT WILL PUSH ACROSS WESTERN OREGON TUE
MORNING...WITH DRAMATICALLY CHANGE IN TEMPERATURES AND SNOW LEVELS.
SNOW LEVELS WILL START NEAR 8000 FEET AHEAD OF THE FRONT TUE
MORNING...BUT DROP STEADILY IN THE AFTERNOON AND EVENING...DOWN TO
NEAR 3000 FEET BY LATE TUE EVENING.
WITH SUCH A COLD AND UNSETTLED AIR MASS...ALONG WITH LOW FREEZING
LEVELS...HEAVIER SHOWERS WILL COME WITH SMALL HAIL. THERE IS ALSO A
POSSIBILITY FOR THUNDERSTORMS...DEPENDING ON THE EXACT TRACK OF THE
COLD POOL ALOFT. SOME MODEST DIRECTIONAL SHEAR WED MAY AID THE
THUNDERSTORM DEVELOPMENT...BUT AGAIN THIS DEPENDS ON THE TIMING OF
INDIVIDUAL SHORTWAVES ROTATING AROUND THE BROADER UPPER LEVEL LOW.
WILL HOLD OFF ON ADDING THUNDER MENTION FOR NOW SINCE THERE IS STILL
A LOT OF UNCERTAINTY AS TO HOW THESE EXACTLY THESE ELEMENTS WILL MIX.
.LONG TERM...WEDNESDAY EVENING THROUGH SUNDAY...A LINGERING CLOSED
LOW PRESSURE SYSTEM WILL KEEP THE AREA SHOWERY AND COOL THROUGH THE
WEEK. WITH THE COLD NATURE OF THE LOW...EXPECT SNOW DOWN TO PASS
LEVEL IN THE CASCADES WEDNESDAY NIGHT....WITH SNOW LEVELS RISING
ABOVE THE PASSES THURSDAY AFTERNOON. MODELS HAVE COME INTO BETTER
AGREEMENT FOR THE LONG TERM AND TAKE THE LOW NORTHEAST ON
SATURDAY...WITH A FEW SHOWERS POSSIBLE AS MOISTURE WRAPS AROUND THE
WEST SIDE OF THE LOW. AT THIS TIME SUNDAY LOOKS DRY BUT
CLOUDY...WITH MODEL DISCREPANCIES EMERGING IN REGARD TO THE NEXT
SYSTEM THAT MAY IMPACT THE AREA LATE SUNDAY. BURGESS
&&
.AVIATION...HIGH PRESSURE WILL CONTINUE TO STRENGTHEN OVERNIGHT
INTO MONDAY ALLOWING VFR CONDITIONS TO PREVAIL FOR THE NEXT 24 HRS.
SCT CLOUDS AROUND 5 K WILL CONTINUE TO DECREASE THIS EVENING. SOME
LIGHT RAIN EARLIER THIS MORNING IN THE CENTRAL WILLAMETTE VALLEY MAY
PROVIDE ENOUGH MOISTURE TO ALLOW A PATCHY MVFR STRATUS DECK TO FORM
LATE TONIGHT...BUT CLEARING SHOULD OCCUR QUICKLY MONDAY MORNING. MID
AND HIGH CLOUDS WILL MOVE INTO THE AREA ON MONDAY AHEAD OF THE NEXT
SYSTEM. TODD
KPDX AND APPROACHES...VFR CONDITIONS THROUGH THE NEXT 24 HRS.
&&
.MARINE...HIGH PRES OVER THE NE PAC WILL CONTINUE TO BUILD OVERNIGHT
WITH N TO NW WINDS. THE LOW END SMALL CRAFT ADVISORY FOR WINDS OVER
THE CENTRAL OREGON COASTAL WATERS WILL CONTINUE AS PRESSURE
GRADIENTS HOLD THROUGH MONDAY...ALLOWING GUSTS TO 25 KT FROM CAPE
FOULWEATHER SOUTH. A FEW GUSTS 20-25 KT ARE POSSIBLE OVER THE
NORTHERN WATERS...BUT OVERALL WINDS SHOULD STAY BELOW CRITERIA. SEAS
HOLDING AT 4 TO 6 FT THROUGH TUE...THOUGH MAY GET BIT CHOPPY WITH
BRISK NW WINDS AT TIMES...MAINLY S OF CASCADE HEAD.
MODELS HAVE BEEN SUGGESTING A LARGE AREA OF 10 TO 13 FT SWELL
ARRIVING BY MID WEEK. WE HAVE SEEN THIS SOLUTION FOR A FEW RUNS NOW
SO CONFIDENCE IS GROWING. TODD
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 PM PDT MONDAY FOR
COASTAL WATERS FROM CASCADE HEAD TO FLORENCE OUT 60 NM.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
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 192222
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
321 PM PDT SUN MAY 19 2013
.SYNOPSIS...HIGH PRESSURE WILL BUILD INTO OREGON THIS EVENING...
CAUSING SKIES TO CLEAR FOR MUCH OF THE FORECAST AREA. THE HIGH
PRESSURE WILL BE STRONGEST OVER THE AREA MONDAY...LEADING TO A SUNNY
AND WARM DAY. HIGH CLOUDS FROM OUR NEXT SYSTEM WILL BEGIN TO INCREASE
LATER MONDAY AND MONDAY NIGHT EVENTUALLY LEADING TO SOME RAIN BY
TUESDAY. THIS SYSTEM WILL COME WITH A SHARP DROP IN TEMPERATURES AND
SNOW LEVELS...WITH COOL AND UNSETTLED WEATHER THEN LIKELY TO CONTINUE
FOR THE REST OF THE WEEK.
&&
.SHORT TERM...TONIGHT THROUGH WEDNESDAY...SKIES HAVE BEEN SLOW TO
CLEAR FOR MOST OF OUR FORECAST AREA TODAY...AS FLOW HAS REMAINED
RATHER LIGHT AND LOW LEVEL MOISTURE REMAINS PERSISTENT. HIGH PRESSURE
IS STRENGTHENING ACROSS THE REGION SO EXPECT SUBSIDENCE TO EVENTUALLY
TAKE OVER FOR CLEARING SKIES THIS EVENING.
EXPECT PLENTY OF SUNSHINE MONDAY AS HIGH PRESSURE BECOMES MORE
DOMINANT. THE AIR MASS WILL ALSO BE WARMING UP A BIT...WITH 850 MB
TEMPS UP FROM +4 DEG C TODAY TO AROUND +10 DEG C MON AFTERNOON PER
THE 12Z ECMWF. WITH NEAR FULL SUNSHINE THIS SHOULD BE GOOD FOR TEMPS
WELL INTO THE 70S FOR THE INLAND VALLEYS. FLOW WILL STILL BE ONSHORE
SO THE COAST WILL REMAIN COOL WITH HIGHS NOT STRAYING TOO FAR FROM 60
DEGREES.
HIGH CLOUDS WILL BE ON THE INCREASE LATER MONDAY INTO MONDAY NIGHT AS
A SIGNIFICANT COLD FRONT APPROACHES FROM ALASKA. RAIN WILL BECOME
LIKELY FOR MOST OF THE FORECAST AREA BY MIDDAY TUESDAY...WITH A SHARP
DROP IN TEMPERATURES AND SNOW LEVEL ASSOCIATED WITH THE COLD FRONT.
INTERIOR VALLEYS WILL SEE HIGHS 15 TO 25 DEGREES COLDER TUE/WED THAN
THEY DID MONDAY. WITH THE COLDER AIR MASS...SNOW LEVEL WILL DROP
BELOW THE CASCADE PASSES. ACCUMULATING SNOW WILL BE POSSIBLE DOWN AS
LOW AS 2500 TO 3000 FT BY TUE NIGHT AND WED...ESPECIALLY DURING THE
NIGHTTIME HOURS. HIGH TEMPS TUE/WED MAY BE COLD ENOUGH TO SET NEW
RECORD LOW MAXES...FOR PDX THIS WOULD BE 52 ON TUE AND 55 WED. OUR
FORECAST OF 54 DEGREES AT PDX WED WOULD ACHIEVE A RECORD.
WITH SUCH A COLD AND UNSETTLED AIR MASS DURING THE MIDWEEK PERIOD...
ALONG WITH LOW FREEZING LEVELS...IT IS LIKELY HEAVIER SHOWERS WILL
COME WITH SMALL HAIL. THERE IS ALSO THE POSSIBILITY FOR THUNDER
DEPENDING ON THE EXACT TRACK OF THE COLD POOL ALOFT. SOME MODEST
DIRECTIONAL SHEAR WEDNESDAY MAY AID THUNDERSTORM DEVELOPMENT...BUT
AGAIN THIS DEPENDS ON THE TIMING OF INDIVIDUAL SHORTWAVES ROTATING
AROUND THE BROADER UPPER LEVEL LOW. WILL HOLD OFF ON ADDING THUNDER
MENTION FOR NOW SINCE THERE IS STILL A LOT OF UNCERTAINTY AS TO HOW
THESE EXACTLY THESE ELEMENTS WILL COME TOGETHER. WEAGLE
.LONG TERM...WEDNESDAY EVENING THROUGH SUNDAY...A LINGERING CLOSED
LOW PRESSURE SYSTEM WILL KEEP THE AREA SHOWERY AND COOL THROUGH THE
WEEK. WITH THE COLD NATURE OF THE LOW...EXPECT SNOW DOWN TO PASS
LEVEL IN THE CASCADES WEDNESDAY NIGHT....WITH SNOW LEVELS RISING
ABOVE THE PASSES THURSDAY AFTERNOON. MODELS HAVE COME INTO BETTER
AGREEMENT FOR THE LONG TERM AND TAKE THE LOW NORTHEAST ON
SATURDAY...WITH A FEW SHOWERS POSSIBLE AS MOISTURE WRAPS AROUND THE
WEST SIDE OF THE LOW. AT THIS TIME SUNDAY LOOKS DRY BUT
CLOUDY...WITH MODEL DISCREPANCIES EMERGING IN REGARD TO THE NEXT
SYSTEM THAT MAY IMPACT THE AREA LATE SUNDAY. BURGESS
&&
.AVIATION...HIGH PRESSURE WILL CONTINUE TO STRENGTHEN OVERNIGHT
INTO MONDAY ALLOWING VFR CONDITIONS TO PREVAIL FOR THE NEXT 24
HRS. CEILINGS AROUND 5K FT WILL CONTINUE THROUGH THIS AFTERNOON
AND EVENING... GRADUALLY DISSIPATING OVERNIGHT. SOME LOW
STRATUS/PATCHY FOG MAY ATTEMPT TO FILL BACK IN AT SITES THAT SAW
SOME LOW CLOUDS THIS MORNING...SUCH AS KSLE IN PARTICULAR. /27
KPDX AND APPROACHES...VFR CONDITIONS THROUGH THE NEXT 24 HRS. BKN
CLOUD DECK AROUND 5K FT WILL GRADUALLY LIFT LATER TONIGHT.
&&
.MARINE...HIGH PRES OVER THE NE PAC WILL STRENGTHEN OVERNIGHT...WITH
N TO NW WINDS. THE SMALL CRAFT ADVISORY FOR WINDS OVER THE CENTRAL
OREGON COASTAL WATERS IS STAYING STRONG AS PRESSURE GRADIENTS
TIGHTEN THROUGH MONDAY... ALLOWING GUSTS TO 25 KT FROM NEWPORT
SOUTH. A FEW GUSTS 20-25 KT ARE POSSIBLE OVER THE NORTHERN
WATERS...BUT OVERALL WINDS SHOULD STAY BELOW CRITERIA. SEAS HOLDING
AT 4 TO 6 FT THROUGH TUE...THOUGH MAY GET BIT CHOPPY WITH BRISK NW
WINDS AT TIMES...MAINLY S OF CASCADE HEAD.
MODELS ARE HINTING AT A LARGE FETCH OF 10 TO 15 FT SWELL ARRIVING
BY MID WEEK. SINCE SOLUTIONS HAVE BEEN RATHER CONSISTENT IN
INDICATING SOME HIGH SWELL BY WED AND THU...WENT AHEAD AND UPPED
SEAS CLOSER TO THE 10 TO 11 FT RANGE. WOULD LIKE A FEW MORE MODEL
RUNS TO DECIDE ON FORECASTING ANY HIGHER SWELL THOUGH.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 PM PDT MONDAY FOR
COASTAL WATERS FROM CASCADE HEAD TO FLORENCE OUT 60 NM.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
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 191615
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
914 AM PDT SUN MAY 19 2013
.SYNOPSIS...CLOUDS AND SCATTERED SHOWERS WILL GRADUALLY DECREASE
TODAY AS HIGH PRESSURE BUILDS INTO THE PACIFIC NORTHWEST. MORE
SUNBREAKS THIS AFTERNOON SHOULD LEAD TO MORE SEASONABLE TEMPERATURES
ESPECIALLY FOR THE LOWLANDS. THE HIGH PRESSURE WILL BE STRONGEST OVER
THE AREA MONDAY...LEADING TO A SUNNY AND WARM DAY. HIGH CLOUDS FROM
OUR NEXT SYSTEM WILL BEGIN TO INCREASE LATER MONDAY AND MONDAY NIGHT
EVENTUALLY LEADING TO SOME RAIN BY TUESDAY. THIS SYSTEM WILL COME
WITH A SHARP DROP IN TEMPERATURES AND SNOW LEVELS...WITH COOL AND
UNSETTLED WEATHER THEN LIKELY TO CONTINUE FOR THE REST OF THE WEEK.
&&
.SHORT TERM...TODAY THROUGH WEDNESDAY...OBSERVATIONS AND RADAR
IMAGERY STILL INDICATE A FEW SHOWERS DOTTING THE FORECAST AREA...
MAINLY OVER THE CASCADES. VISIBLE SATELLITE IS BEGINNING TO SHOW SOME
CLEARING OVER THE TUALATIN VALLEY AND WESTERN PORTIONS OF THE
WILLAMETTE AS WELL. THIS LIKELY DUE TO INCREASED ONSHORE FLOW AND
DOWNSLOPING ON THE EAST SIDE OF THE COAST RANGE. THIS OVERALL PATTERN
WILL CONTINUE THROUGH THE DAY...WITH HIGH PRESSURE BUILDING IN CLOUD
COVER WILL GRADUALLY DECREASE WITH THE WEST HALF OF THE WILLAMETTE
VALLEY AND THE HOOD RIVER VALLEY BEING THE SUNNIEST. WITH THE
INCREASE IN SUNSHINE TEMPS SHOULD COME CLOSER TO SEASONAL NORMS...
WITH MID TO UPPER 60S.
MAIN CHANGE TO THE MORNING FCST WAS TO HANG ON TO THE CLOUD COVER
OVER THE HIGHER TERRAIN A LITTLE LONGER...BUT OTHERWISE THE FORECAST
LOOKS TO BE IN GOOD SHAPE. REMAINDER OF SHORT/LONG TERM DISCUSSION IS
FROM THE PREVIOUS SHIFT AND STILL VALID... WEAGLE
MONDAY WILL BE THE SUNNIEST AND WARMEST DAY OF THE WORK WEEK WITH
HIGH PRESSURE REMAINING OVER THE AREA. MODELED 850MB TEMPERATURES
SUGGEST DAYTIME HIGHS WILL WARM A FEW DEGREES ABOVE NORMAL MONDAY.
A SIGNIFICANT CHANGE IN WEATHER IS EXPECTED TUESDAY AS AN
UNSEASONABLY DEEP AND COLD UPPER LOW WILL MOVE OVER THE REGION. THIS
LOW WILL RETURN RAIN ON TUESDAY...WITH SNOW LEVELS LOWERING TO THE
CASCADE PASSES TUESDAY NIGHT. WEDNESDAY WILL BE THE COOLEST DAY OF
THE WEEK WITH THE UPPER LOW CONTINUING RAIN AND MOUNTAIN SNOW
SHOWERS. INSTABILITY WILL RESULT IN ENHANCED SHOWERS IN THE
AFTERNOONS TUESDAY AND WEDNESDAY WITH SOME OF THE HEAVIER SHOWERS
CONTAINING SMALL HAIL. QPF AND CORRESPONDINGLY SNOW AMOUNTS ARE
DIFFICULT TO FORECAST FOR THESE TYPE OF LOANS.
CURRENTLY MODELS SUGGEST THAT SNOW AMOUNTS WILL REMAIN BELOW ADVISORY
CRITERIA...BUT CONVECTIVE SHOWERS TEND TO PRODUCE MORE THAN EXPECTED
PRECIPITATION. FORECASTING WHERE THE SHOWERS WILL BE THE MOST
CONSISTENT AND LIKELY HAVE THE HIGHER ACCUMULATIONS ADDS ANOTHER
CHALLENGE TO THE FORECAST. THE CURRENT FORECAST IS FOR NON-ADVISORY
SNOW...BUT WOULD NOT BE SURPRISED IF THIS CHANGES AS WE HAVE MORE
CONSISTENT MODEL DATA THE NEXT COUPLE OF DAYS.
.LONG TERM...WEDNESDAY EVENING THROUGH SATURDAY. CLOSED LOW PRESSURE
SYSTEM WILL LINGER OVER THE PAC NW THROUGH AT LEAST FRIDAY. EXPECT A
MORE DIURNAL TREND OF THE SHOWERS THURSDAY AND FRIDAY WITH LESS
SHOWERS AND POSSIBLE SUN BREAKS IN THE MORNINGS WITH SHOWER
ENHANCEMENT IN THE AFTERNOONS...ESPECIALLY FOR THE HIGHER TERRAIN.
TEMPERATURES WILL REMAIN BELOW THE SEASONAL NORMAL. MODELS ARE COMING
INTO BETTER AGREEMENT ON THE LOW MOVING EAST OF THE AREA FRIDAY
EVENING. DESPITE THE DEPARTURE OF THIS LOW...GENERAL LOW PRESSURE
WILL REMAIN OVER THE AREA AND CONTINUE SHOWERY AND
COOL CONDITIONS THROUGH MEMORIAL DAY WEEKEND.
&&
.AVIATION...MOIST AIR MASS MAINTAINS MVFR AND VFR CEILINGS THIS
MORNING. EXPECT CLOUDS TO GRADUALLY BREAK UP CLOSER TO 19Z...WITH
PREDOMINANTLY VFR CONDITIONS CONTINUING THROUGH THIS EVENING. HIGH
PRESSURE STRENGTHENS OVERNIGHT...WITH SOLID VFR EXPECTED THROUGH
MON.
KPDX AND APPROACHES...MVFR CEILINGS PERSISTS THROUGH 19Z/20Z THIS
MORNING...THEN EXPECT VFR CONDITIONS THROUGH TONIGHT AND MONDAY.
BKN CLOUD DECK AROUND 5K WILL LIKELY LINGER THROUGH THIS EVENING.
/27
&&
.MARINE...HIGH PRES OVER THE NE PAC WILL CONTINUE TO STRENGTHEN
TODAY AND TONIGHT...WITH N TO NW WINDS. THESE WINDS WILL INCREASE
AS PRES GRADIENTS TIGHTEN THROUGH MON...WITH WIND GUSTS TO 25 KT S
OF NEWPORT IN AFTERNOON/EVENINGS. WILL MAINTAIN SMALL CRAFT
ADVISORY FOR CENTRAL OREGON COASTAL WATERS FOR SUCH WINDS FROM
THIS AFTERNOON THROUGH MON EVENING. WINDS WEAKER TO THE N...BUT
COULD GET A BIT GUSTY ON MON.
SEAS HOLDING AT 4 TO 6 FT THROUGH TUE...THOUGH MAY GET BIT CHOPPY
WITH BRISK NW WINDS AT TIMES...MAINLY S OF CASCADE HEAD.
QUESTIONABLE WEATHER FOR MIDDLE OF NEXT WEEK. MODELS INDICATE
LARGE FETCH OF 10 TO 15 FT SWELL ARRIVING BY WED AND THU. THIS IS
DUE TO MODELS SPINNING UP ANOTHER RATHER TIGHT LOW PRES OFF THE
OREGON COAST ON TUE AND WED. NOT CONVINCED THIS WILL PAN OUT AS
MODELS SUGGEST...SO WILL TREND CLOSER TO 10 FT AND WAIT FOR FURTHER
CONSISTENCY IN MODEL DATA BEFORE BITING.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS FROM NOON TODAY TO MIDNIGHT PDT
MONDAY NIGHT FOR COASTAL WATERS FROM CASCADE HEAD TO FLORENCE
OUT 60 NM.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
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 190947
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
246 AM PDT SUN MAY 19 2013
.SYNOPSIS...SHOWERS WILL DECREASE THIS MORNING AS A WEAK
WEATHER SYSTEM MOVES EAST OF THE AREA AND HIGH PRESSURE BUILDS. MORE
SUNBREAKS SUNDAY AFTERNOON SHOULD LEAD TO MORE SEASONABLE
TEMPERATURES. HIGH PRESSURE WILL HOLD OVER THE AREA MONDAY WHICH WILL
BE SUNNY AND WARM. HIGH CLOUDS WILL BEGIN TO INCREASE FROM THE
NORTHWEST MONDAY EVENING IN ADVANCE OF THE NEXT SYSTEM...WHICH WILL
BRING A DRAMATIC CHANGE BACK TO CHILLY AND UNSETTLED WEATHER TUESDAY
THROUGH FRIDAY.
&&
.SHORT TERM...RADAR IMAGERY SHOWS SHOWERS ACROSS NW OREGON EARLY THIS
MORNING AS AN UPPER LEVEL SHORTWAVE TROUGH MOVES OVER THE REGION.
THIS WAVE WILL MOVE EAST OF THE CASCADES AROUND SUNRISE AND HIGH
PRESSURE WILL BUILD OVER THE AREA. THE SHOWERS WILL BE MOSTLY
CONFINED TO THE COAST RANGE AND THE CASCADES AFTER SUNRISE...THEN
DISSIPATE IN THE AFTERNOON. CLEARING THIS AFTERNOON WILL RESULT IN
MORE SUNSHINE AND INLAND TEMPERATURES SHOULD WARM TO THE MID AND
UPPER 60S.
MONDAY WILL BE THE SUNNIEST AND WARMEST DAY OF THE WORK WEEK WITH
HIGH PRESSURE REMAINING OVER THE AREA. MODELED 850MB TEMPERATURES
SUGGEST DAYTIME HIGHS WILL WARM A FEW DEGREES ABOVE NORMAL MONDAY.
A SIGNIFICANT CHANGE IN WEATHER IS EXPECTED TUESDAY AS AN
UNSEASONABLY DEEP AND COLD UPPER LOW WILL MOVE OVER THE REGION. THIS
LOW WILL RETURN RAIN ON TUESDAY...WITH SNOW LEVELS LOWERING TO THE
CASCADE PASSES TUESDAY NIGHT. WEDNESDAY WILL BE THE COOLEST DAY OF
THE WEEK WITH THE UPPER LOW CONTINUING RAIN AND MOUNTAIN SNOW
SHOWERS. INSTABILITY WILL RESULT IN ENHANCED SHOWERS IN THE
AFTERNOONS TUESDAY AND WEDNESDAY WITH SOME OF THE HEAVIER SHOWERS
CONTAINING SMALL HAIL. QPF AND CORRESPONDINGLY SNOW AMOUNTS ARE
DIFFICULT TO FORECAST FOR THESE TYPE OF LOANS.
CURRENTLY MODELS SUGGEST THAT SNOW AMOUNTS WILL REMAIN BELOW ADVISORY
CRITERIA...BUT CONVECTIVE SHOWERS TEND TO PRODUCE MORE THAN EXPECTED
PRECIPITATION. FORECASTING WHERE THE SHOWERS WILL BE THE MOST
CONSISTENT AND LIKELY HAVE THE HIGHER ACCUMULATIONS ADDS ANOTHER
CHALLENGE TO THE FORECAST. THE CURRENT FORECAST IS FOR NON-ADVISORY
SNOW...BUT WOULD NOT BE SURPRISED IF THIS CHANGES AS WE HAVE MORE
CONSISTENT MODEL DATA THE NEXT COUPLE OF DAYS.
.LONG TERM...WEDNESDAY EVENING THROUGH SATURDAY. CLOSED LOW PRESSURE
SYSTEM WILL LINGER OVER THE PAC NW THROUGH AT LEAST FRIDAY. EXPECT A
MORE DIURNAL TREND OF THE SHOWERS THURSDAY AND FRIDAY WITH LESS
SHOWERS AND POSSIBLE SUN BREAKS IN THE MORNINGS WITH SHOWER
ENHANCEMENT IN THE AFTERNOONS...ESPECIALLY FOR THE HIGHER TERRAIN.
TEMPERATURES WILL REMAIN BELOW THE SEASONAL NORMAL. MODELS ARE COMING
INTO BETTER AGREEMENT ON THE LOW MOVING EAST OF THE AREA FRIDAY
EVENING. DESPITE THE DEPARTURE OF THIS LOW...GENERAL LOW PRESSURE
WILL REMAIN OVER THE AREA AND CONTINUE SHOWERY AND
COOL CONDITIONS THROUGH MEMORIAL DAY WEEKEND.
&&
.AVIATION...RATHER MOIST AIR MASS ACROSS THE REGION THIS MORNING
WITH A MIX OF VFR AND MVFR CEILINGS. LITTLE CHANGE EXPECTED
THROUGH THE MORNING. WILL LIKELY SEE WIDESPREAD MVFR CEILINGS
BEFORE SUNRISE...THEN GRADUALLY BREAKUP OF CLOUDS AFTER 18Z AS
FLOW TURNS MORE N TO NWLY.
KPDX AND APPROACHES...MVFR CEILINGS WILL LIKELY FORM BY 12Z...AND
PERSIST THROUGH MUCH OF THE MORNING. LOCAL GUIDANCE SUGGESTS A
RETURN OF VFR CONDITIONS AROUND 19Z TO 20Z SUN. WILL MAINTAIN
THIS TREND IN THE 12Z TAFS.
&&
.MARINE...HIGH PRES OVER THE NE PAC WILL STRENGTHEN TONIGHT AND
SUN...WITH N TO NW WINDS. THESE WINDS WILL INCREASE AS PRES
GRADIENTS TIGHTEN SUN AND MON...WITH WIND GUSTS TO 25 KT S OF
NEWPORT IN AFTERNOON/EVENINGS. WILL MAINTAIN SMALL CRAFT ADVISORY
FOR CENTRAL OREGON COASTAL WATERS FOR SUCH WINDS FROM SUN
AFTERNOON THROUGH MON EVENING. WINDS WEAKER TO THE N...BUT COULD
GET A BIT GUSTY ON MON.
SEAS HOLDING AT 4 TO 6 FT THROUGH TUE...THOUGH MAY GET BIT CHOPPY
WITH BRISK NW WINDS AT TIMES...MAINLY S OF CASCADE HEAD.
QUESTIONABLE WEATHER FOR MIDDLE OF NEXT WEEK. MODELS INDICATE
LARGE FETCH OF 10 TO 15 FT SWELL ARRIVING BY WED AND THU. THIS IS
DUE TO MODELS SPINNING UP ANOTHER RATHER TIGHT LOW PRES OFF THE
OREGON COAST ON TUE AND WED. NOT CONVINCED THIS WILL PAN OUT AS
MODELS SUGGEST...SO WILL TREND CLOSER TO 10 FT AND WAIT FOR FURTHER
CONSISTENCY IN MODEL DATA BEFORE BITING.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS FROM NOON TODAY TO MIDNIGHT PDT
MONDAY NIGHT FOR COASTAL WATERS FROM CASCADE HEAD TO
FLORENCE OR OUT 10 NM-WATERS FROM CASCADE HEAD TO FLORENCE
OR FROM 10 TO 60 NM.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
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 190319
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
819 PM PDT SAT MAY 18 2013
.SYNOPSIS...SHOWERS WILL SLOWLY DECREASE TONIGHT AND SUNDAY AS A WEAK
WEATHER SYSTEM MOVES OUT OF THE AREA INTO THE GREAT BASIN. MORE
SUNBREAKS SUNDAY SHOULD LEAD TO MORE SEASONABLE TEMPERATURES. MONDAY
WILL BE A PLEASANT...SUNNY AND WARM DAY UNDER HIGH PRESSURE WITH
TEMPS IN THE LOWER TO MID 70S. HIGH CLOUDS WILL BEGIN TO INCREASE
FROM THE NORTHWEST LATER IN THE DAY IN ADVANCE OF OUR NEXT
SYSTEM...WHICH WILL BRING A DRAMATIC CHANGE BACK TO CHILLY AND
UNSETTLED WEATHER TUESDAY THROUGH FRIDAY.
&&
.SHORT TERM...A WEAK FRONT WILL PUSH ASHORE THIS EVENING AND INTO THE
OVERNIGHT HOURS WITH DECREASING SHOWERS BEHIND THE FRONT. ON
SUNDAY...SHOWERS SHOULD MAINLY BE CONFINED TO THE FOOTHILLS AND
CASCADES AS THE FRONT EXITS THE REGION AND HIGH PRESSURE BUILDS IN.
MOST AREAS WILL SEE SOME SUNSHINE IN THE AFTERNOON HOURS AS WARM AIR
ALOFT MOVES AND STABILIZES THE ATMOSPHERE.
MONDAY LOOKS TO BE THE SUNNIEST AND WARMEST DAY NEXT WEEK WITH HIGH
PRESSURE REMAINING OVER THE AREA. TEMPS EXPECTED TO BE A FEW DEGREES
ABOVE NORMAL MONDAY.
A SIGNIFICANT PATTERN CHANGE BEGINS TO TAKE PLACE ON TUES THAT WILL
LAST THROUGH THE WEEK. AN UNSEASONABLY DEEP AND COLD UPPER LOW WILL
SINK SOUTHEAST INTO WA/OR SPREADING RAIN ACROSS THE REGION. RAIN
APPEARS LIKELY A GOOD PORTION OF THE DAY TUESDAY...WITH SNOW LEVELS
LOWERING TO THE CASCADE PASSES TUE NIGHT. THERE IS AN OUTSIDE CHANCE
WE MAY NEED TO CONSIDER SNOW ADVISORIES FOR THE CASCADES AS EARLY AS
TUE NIGHT. TW
.LONG TERM...TUESDAY EVENING THROUGH SATURDAY. CLOSED LOW PRESSURE
SYSTEM WILL LINGER OVER THE PAC NW THROUGH THE WEEK. WITH THE COLD
NATURE OF THE LOW...RECORD LOW MAXIMUM TEMPERATURES ARE POSSIBLE ON
WEDNESDAY...WITH SNOW DOWN TO PASS LEVEL LIKELY IN THE CASCADES.
THURSDAY AND BEYOND MODELS BEGIN TO DISAGREE ON WHERE THE LOW WILL
PROPAGATE...HOWEVER THE OVERALL TREND WILL REMAIN...WITH SHOWERY AND
COOL CONDITIONS PERSISTING THROUGH AT LEAST SATURDAY. BURGESS
&&
.AVIATION...RATHER MOIST AIR MASS ACROSS THE REGION THIS EVENING
WITH A MIX OF VFR AND MVFR CIGS. LITTLE CHANGE TONIGHT...THOUGH
SHOWERS WILL END OVERNIGHT. IF GET ANY CLEARING...WINDS ARE LIGHT
SO MAY SEE PATCHY FOG S OF KSLE AND ALONG COAST...BUT AT MOMENT
FEEL ONSHORE FLOW JUST ENOUGH THAT CLOUDS WILL REFORM ACROSS THE
REGION. LIKELY WILL SEE WIDESPREAD MVFR CIGS LATER TONIGHT INTO
SUN AM...THEN GRADUALLY BREAKUP OF CLOUDS AFTER 18Z AS FLOW TURNS
MORE N TO NWLY.
KPDX AND APPROACHES...EXPECT MOSTLY VFR CONDITIONS THIS EVENING.
HOWEVER...SUSPECT WITH MOIST LOW LEVELS...AREAS OF MVFR CIGS WILL
FORM AFTER 08Z...AND PERSIST INTO SUN AM. LOCAL GUIDANCE SUGGESTS
CIGS WOULD BREAK UP WITH SCATTERED CLOUDS AROUND 19Z TO 20Z SUN.
WILL MAINTAIN THIS TREND IN THE 06Z TAFS.ROCKEY.
&&
.MARINE...WEAKENING FRONT NOW JUST INLAND. HIGH PRES OVER THE NE
PAC WILL STRENGTHEN TONIGHT AND SUN...WITH N TO NW WINDS. THESE
WINDS WILL INCREASE AS PRES GRADIENT TIGHTENS ON SUN AND MON...
WITH WINDS GUSTY TO 25 KT S OF NEWPORT IN AFTERNOON/EVENINGS. WILL
HOIST SMALL CRAFT ADVISORY FOR CENTRAL OREGON COASTAL WATERS FOR
SUCH WINDS FROM SUN AFTERNOON THROUGH MON EVENING. WINDS WEAKER TO
THE N...BUT COULD GET BIT GUSTY ON MON.
SEAS HOLDING AT 4 TO 6 FT TONIGHT THROUGH TUE...THOUGH MAY GET BIT
CHOPPY WITH BRISK NW WINDS AT TIMES...MAINLY S OF CASCADE HEAD.
QUESTIONABLE WEATHER FOR MIDDLE OF NEXT WEEK. MODELS INDICATE
LARGE FETCH OF 10 TO 15 FT SWELL ARRIVING BY WED AND THU. THIS IS
DUE TO MODELS SPINNING UP ANOTHER RATHER TIGHT LOW PRES OFF THE
OREGON COAST ON TUE AND WED. NOT CONVINCED THIS WILL PAN OUT AS
MODELS SUGGEST...SO WILL TREND CLOSER TO 10 AS WANT TO SEE FURTHER
CONSISTENCY IN MODEL DATA BEFORE BITING. ROCKEY.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS FOR SUN AFTERNOON THROUGH
MON EVENING ON THE CENTRAL OREGON COASTAL WATERS...OR FROM
CASCADE HEAD TO FLORENCE AND OUT 60 NM.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
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 182135
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
234 PM PDT SAT MAY 18 2013
.SYNOPSIS...PLENTY OF CLOUDS AND OCCASIONAL RAIN TODAY AS A WEAK LOW
PRESSURE SYSTEM SLOWLY MOVES INTO OREGON AND WASHINGTON. SHOWERS WILL
SLOWLY DECREASE TONIGHT AND SUNDAY AS THE SYSTEM MOVES INTO THE
GREAT BASIN AND FALLS APART. MORE SUNBREAKS SUNDAY SHOULD LEAD TO
MORE SEASONABLE TEMPERATURES. MONDAY IS SHAPING UP TO BE A PLEASANT
SUNNY AND WARM DAY UNDER HIGH PRESSURE WITH TEMPS IN THE LOWER TO MID
70S. HIGH CLOUDS WILL BEGIN TO INCREASE FROM THE NORTHWEST LATER IN
THE DAY IN ADVANCE OF OUR NEXT SYSTEM...WHICH WILL BRING A DRAMATIC
CHANGE BACK TO CHILLY AND UNSETTLED WEATHER TUESDAY THROUGH FRIDAY.
&&
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT...VISIBLE SATELLITE IMAGERY
SHOWS SOLID CLOUD COVER ACROSS THE DISTRICT THIS AFTERNOON. KRTX
RADAR SHOWS AN AREA OF LIGHT RAIN SPREADING ACROSS WASHINGTON COUNTY
AND ENTERING THE GREATER PORTLAND AND EVENTUALLY VANCOUVER METRO
AREA. ADDITIONALLY AREAS OF LIGHT RAIN PERSIST ALONG THE COAST AND
MUCH OF THE REST OF OUR FORECAST AREA. SNOW LEVELS REMAIN RATHER
HIGH...ODOT PASS CAMS SHOW OCCASIONAL RAIN AND IT APPEARS TO BE
RAINING AT TIMBERLINE AS WELL.
WEAK AND POORLY DEFINED LOW PRESSURE CIRCULATION JUST OFFSHORE FROM
ASTORIA WILL DRAG A WEAK COLD FRONT ONSHORE OVER THE NEXT FEW HOURS
WITH DECREASING SHOWERS THEREAFTER. WHAT IS LEFT OF THE FRONT WILL
FINALLY LUMBER EAST ACROSS THE CASCADES TONIGHT WITH DECREASING
SHOWERS BEHIND THE FRONT. BY SUNDAY MORNING SHOWERS WILL BE MAINLY
CONFINED TO THE HIGHER TERRAIN...THOUGH A STRAY SHOWER IS STILL
POSSIBLE ELSEWHERE DUE TO WEAK SHALLOW INSTABILITY.
MADE VERY FEW CHANGES FOR MONDAY AND TUESDAY. THE MOVE THE MIDNIGHT
SHIFT MADE TO BUMP UP MONDAY TEMPS INTO THE 70S APPEARS TO BE A GOOD
ONE. THE AIR MASS LOOKS RATHER DRY THROUGHOUT MONDAY ON NAM BUFR
SOUNDINGS...FROM EUGENE ALL THE WAY UP TO PORTLAND. WITH 850 MB TEMPS
PUSHING +10 DEG C IN THE WILLAMETTE VALLEY...HIGHS COULD GET WELL
INTO THE 70S SOME AREAS WITH PLENTY OF SUNSHINE. ONSHORE GRADIENTS
WILL KEEP THE COAST FROM WARMING UP TOO MUCH.
MODELS SHOWING GOOD AGREEMENT ON RAIN FROM OUR NEXT SYSTEM HOLDING
OFF UNTIL TUESDAY MORNING. AS TUESDAY PROGRESSES IT APPEARS AN
UNSEASONABLY DEEP AND COLD UPPER LOW WILL SINK SOUTHEAST INTO WA/OR
SPREADING RAIN ACROSS THE REGION. RAIN APPEARS LIKELY A GOOD PORTION
OF THE DAY TUESDAY...WITH SNOW LEVELS LOWERING TO THE CASCADE PASSES
TUE NIGHT. THERE IS AN OUTSIDE CHANCE WE MAY NEED TO EVENTUALLY
CONSIDER SNOW ADVISORIES FOR THE CASCADES AS EARLY AS TUE NIGHT.
WEAGLE
.LONG TERM...TUESDAY EVENING THROUGH SATURDAY...FEW CHANGES. CLOSED
LOW PRESSURE SYSTEM WILL LINGER OVER THE PAC NW THROUGH THE WEEK.
WITH THE COLD NATURE OF THE LOW...RECORD LOW MAXIMUM TEMPERATURES
ARE POSSIBLE ON WEDNESDAY...WITH SNOW DOWN TO PASS LEVEL LIKELY IN
THE CASCADES. THURSDAY AND BEYOND MODELS BEGIN TO DISAGREE ON WHERE
THE LOW WILL PROPAGATE...HOWEVER THE OVERALL TREND WILL
REMAIN...WITH SHOWERY AND COOL CONDITIONS PERSISTING THROUGH AT
LEAST SATURDAY. BURGESS
&&
.AVIATION...MIX OF VFR AND MVFR CIGS ACROSS THE REGION. A
WEAKENING FRONT IS PUSHING ACROSS THE REGION...BUT BACK EDGE OF
THE FRONT IS STILL OFFSHORE AND NOT LIKELY TO CLEAR THE CASCADES
UNTIL THIS EVENING. NOT MUCH CHANGE...WITH SCATTERED SHOWERS AND
MOSTLY LOW VFR AND POCKETS OF MVFR THROUGH TONIGHT. CASCADES AND
PASSES WILL FREQUENTLY BE OBSCURED IN CLOUDS. SHOWERS SHOULD
DIMINISH OVERNIGHT BEHIND THE FRONT...WITH MVFR CIGS AT THE COAST
AND MOSTLY VFR INLAND. SOME PATCHY FOG POSSIBLE TOMORROW MORNING
IN THE SOUTHERN WILLAMETTE VALLEY IF ANY CLEARING
OCCURS...POSSIBLY AFFECTING KEUG.
KPDX AND APPROACHES...EXPECT A MIX OF VFR AND MVFR IN SCATTERED
SHOWERS THROUGH THIS AFTERNOON AS A COLD WORKS ITS WAY THROUGH.
SHOWER ACTIVITY SHOULD DECREASE LATER THIS EVENING BEHIND THE
FRONTAL PASSAGE. MOSTLY VFR CONDITIONS OVERNIGHT. PYLE
EXPECT LIGHT RAIN OR SHOWERS OFF AND ON THROUGH THE DAY.
PREDOMINANTLY VFR CONDITIONS MAY DROP TO MVFR AT TIMES DURING HEAVIER
SHOWERS. SHOWER ACTIVITY SHOULD TAPER OFF SOMEWHAT THIS EVENING...
WITH MAINLY VFR CONDITIONS DURING THE EVENING AND OVERNIGHT HOURS.
PYLE
&&
.MARINE...A COLD FRONT IS PUSHING THROUGH THE COASTAL WATERS THIS
AFTERNOON. THE FRONT HAS BEEN SLOWER THAN EXPECTED...SO DECIDED
TO EXTEND THE SMALL CRAFT ADVISORY FOR WINDS INTO THE EARLY
EVENING HRS. EXPECT WINDS TO DECREASE AND TURN NW LATER THIS
EVENING BEHIND THE FRONT. HIGH PRES WILL BUILD OVER THE NE PAC
SUN INTO EARLY NEXT WEEK. IT APPEARS THAT THERE WILL BE A FEW
CHANCES FOR SMALL CRAFT ADVISORIES FOR WINDS OVER THE NEXT FEW
DAYS. SUNDAY AND MONDAY MAY SEE WIND GUSTS INTO THE 20 TO 25 KT
RANGE DURING THE LATE AFTERNOON AND EARLY EVENING HRS.
SEAS REMAIN AT 5 TO 6 FT THROUGH THE WEEKEND. SEAS MAY BUMP UP A
BIT DURING THE PERIODS OF GUSTY WINDS ON SUN AND MON. A LARGE
LOW PRESSURE SYSTEM MAY BRING ANOTHER SMALL CRAFT FOR WINDS ON
WED...ALONG WITH SEAS ABOVE 10 FT. PYLE
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 7 PM PDT THIS EVENING FOR
COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
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 181609
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
908 AM PDT SAT MAY 18 2013
.SYNOPSIS...A WEAK FRONTAL SYSTEM IS SPREADING LIGHT RAIN ACROSS
FORECAST AREA THIS MORNING. OCCASIONAL RAIN WILL CONTINUE THROUGH THE
DAY WITH CLOUDY SKIES AND TEMPS STUCK AROUND 60 DEGREES FOR THE
LOWLANDS. SNOW LEVELS WILL REMAIN WELL ABOVE THE PASSES. SHOWERS WILL
GRADUALLY DECREASE TONIGHT AND SUNDAY AS THE SYSTEM MOVES INTO THE
GREAT BASIN AND HIGH PRESSURE BEGINS TO BUILD. THIS HIGH PRESSURE
SHOULD RESULT IN DRIER AND WARMER CONDITIONS SUN NIGHT INTO MON.
HOWEVER IT APPEARS LIKELY AN UNSEASONABLY COLD UPPER LOW WILL BRING
COOL AND UNSETTLED WEATHER TUESDAY THROUGH FRIDAY.
&&
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT...LATEST RADAR IMAGERY AND
SURFACE OBSERVATIONS SHOW LIGHT RAIN SPREADING ACROSS THE PORTLAND
AND VANCOUVER METRO THIS MORNING...MOVING EAST INTO THE CASCADES. A
WEAK FRONTAL SYSTEM MOVING ONSHORE IS RESPONSIBLE FOR THIS...WITH THE
FIRST BAND OF RAIN ASSOCIATED WITH WEAK ISENTROPIC LIFT.
LATEST MSAS SFC PRESSURE ANALYSIS SHOWS AN ELONGATED LOW PRESSURE
TROUGH JUST OFFSHORE...WHICH SEEMS TO MATCH VISIBLE IMAGERY FAIRLY
WELL. LOOPING THIS IMAGERY SEEMS TO SHOW A VERY FAINT CIRCULATION IN
THE LOW CLOUDS CENTERED NEAR 46N/126W...MOVING NORTHEAST. THIS WEAK
LOW WILL LIKELY DRAG A WEAK COLD FRONT ACROSS THE DISTRICT THIS
AFTERNOON...SPREADING ANOTHER BATCH OF RAIN ACROSS THE FORECAST AREA.
OVERALL RAINFALL AMOUNTS TODAY THROUGH THIS EVENING WILL PROBABLY BE
0.10-0.20 INCH IN THE VALLEYS...UP TO 0.50-0.75 INCH IN THE HIGHER
TERRAIN. EXPECT LITTLE TO NO BREAKS IN THE CLOUDS TODAY WITH THE VERY
MOIST AIR MASS...TEMPS WILL STRUGGLE TO REACH 60 DEGREES AND MOS
GUIDANCE APPEARS TO BE CATCHING ON TO THIS CONCEPT.
THERE WILL BE MORE BREAKS IN THE CLOUDS SUNDAY AS HIGH PRESSURE
BEGINS TO BUILD INTO THE REGION. SOME WEAK AND SHALLOW INSTABILITY
LEFT BEHIND BY ALLOW AN ISOLATED SHOWER OR TWO...WITH THE BEST CHANCE
OVER THE HIGHER TERRAIN. THE AIR MASS WILL BE RAPIDLY WARMING
ALOFT...CAPPING THE INSTABILITY AND KEEPING IT TOO SHALLOW FOR TSTMS
SUNDAY DESPITE THE WARMER SFC TEMPS IN THE MID TO UPPER 60S. WEAGLE
REMAINDER OF FCST DISCUSSION UNCHANGED FROM PREVIOUS SHIFT...HIGH
PRESSURE MAINTAIN DRY WEATHER FOR MONDAY WHICH WILL LIKELY BE
THE WARMEST DAY OF THE WEEK. INCREASED SUNSHINE SHOULD WARM INTERIOR
TEMPERATURES TO SLIGHTLY ABOVE NORMAL...LOW 70S AND COASTAL AREAS TO
NEAR NORMAL...LOWER 60S. AN UPPER LEVEL LOW WILL APPROACH MONDAY
NIGHT AND BRING A RETURN OF SHOWERS AND MUCH COOLER WEATHER TO THE
REGION. MODELS HAVE BACKED OFF THE TIMING OF THE ONSET OF RAIN AROUND
12 HOURS. THE COLDEST AIR ASSOCIATED WITH THE LOW WILL BEGIN MOVING
OVER THE AREA TUESDAY NIGHT AND SNOW LEVELS SHOULD LOWER TO AROUND
3500 TO 4000 FEET.
.LONG TERM...WEDNESDAY THROUGH FRIDAY...A COLD CLOSED LOW WILL
CONTINUE UNSETTLED WEATHER WITH UNSEASONAL COLD TEMPERATURES
WEDNESDAY...WITH RECORD LOW MAXIMUM TEMPERATURES POSSIBLE. WEDNESDAY
WILL BE THE COLDEST DAY OF THE WORK WEEK. TEMPERATURES WILL REMAIN
BELOW THE SEASONAL NORMALS THURSDAY AND FRIDAY AS A COUPLE OF
SHORTWAVE TROUGHS WILL CONTINUE SHOWERY AND COOL CONDITIONS.
&&
.AVIATION...A FRONTAL BOUNDARY MOVING THROUGH THE REGION WILL
BRING PERIODS OF LIGHT RAIN OR SHOWERS THROUGH MUCH OF THE DAY.
EXPECT A MIX OF VFR AND MVFR CONDITIONS...WITH THE PERIODS OF MVFR
COINCIDING WITH THE HEAVIER SHOWERS. EXPECT SHOWER ACTIVITY TO
CONTINUE BUT BECOME MORE SCATTERED THIS EVENING BEHIND THE FRONTAL
PASSAGE. EXPECT MAINLY VFR CONDITIONS THIS EVENING...WITH MVFR
CIGS PUSHING INTO THE COAST OVERNIGHT.
KPDX AND APPROACHES...EXPECT LIGHT RAIN OR SHOWERS OFF AND ON
THROUGH THE DAY. PREDOMINANTLY VFR CONDITIONS MAY DROP TO MVFR AT
TIMES DURING HEAVIER SHOWERS. SHOWER ACTIVITY SHOULD TAPER OFF
SOMEWHAT THIS EVENING...WITH MAINLY VFR CONDITIONS DURING THE
EVENING AND OVERNIGHT HOURS. PYLE
&&
.MARINE...A FRONT WILL PUSH ACROSS THE COASTAL WATERS THIS
MORNING...THEN INLAND EARLY THIS AFTERNOON. NOT A LOT OF WIND
CURRENTLY BEING OBSERVED...BUT EXPECT THAT WINDS WILL PICK UP A
BIT LATER THIS MORNING AS THE COLD FRONT COMES THROUGH. THERE
SEEMS SO BE ENOUGH GRADIENT TO POP GUSTS 20 TO 25 KT RIGHT AHEAD
OF THE FRONT. SO WILL MAINTAIN CURRENT SMALL CRAFT ADVISORY.
OTHERWISE...WINDS TURN W TO NW BEHIND THE FRONT IN THE AFTERNOON
AND BEGIN TO EASE.
HIGH PRES WILL BUILD OVER THE NE PAC SUN INTO EARLY NEXT WEEK.
THIS WILL KEEP NW WINDS 10 TO 15 KT THROUGH MUCH OF THE COMING
WEEK...THOUGH MAY BRIEFLY GET 20 TO 25 KT GUSTS MON AFTERNOON INTO
THE EVENING.
SEAS REMAIN AT 5 TO 6 FT FOR INTO EARLY NEXT WEEK. MAY SEE SEAS
BUILD UP AND BECOME CHOPPY AT TIMES WITH THE BRISK NW WINDS ON THE
CENTRAL OREGON COASTAL WATERS NEXT WEEK.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 3 PM PDT THIS AFTERNOON FOR
COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
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 180946
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
246 AM PDT SAT MAY 18 2013
.SYNOPSIS...A COLD FRONT WILL SPREAD LIGHT RAIN ACROSS THE REGION
TODAY. SHOWERS WILL DECREASE TONIGHT BUT CONTINUE OVER THE MOUNTAINS
THROUGH SUNDAY MORNING. HIGH PRESSURE WILL RESULT IN DRIER AND
GRADUALLY WARMER TEMPERATURES SUNDAY AND MONDAY. AN UPPER LEVEL LOW
WILL BRING A RETURN OF RAIN AND MUCH COLDER WEATHER TUESDAY WITH
LIGHT SNOW ACCUMULATIONS POSSIBLE BELOW THE CASCADE PASSES BY
WEDNESDAY MORNING. COOL AND SHOWERY WEATHER WILL CONTINUE THROUGH
FRIDAY.
&&
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT...THE NEXT FRONT IS
APPROACHING THE COAST. ASCAT SATELLITE DERIVED WINDS SHOWED THE COLD
FRONT AROUND 300 MILES OFFSHORE AT 11 PM LAST NIGHT. RADAR IMAGERY
SHOWS RAIN AHEAD OF THE FRONT JUST REACHING THE NORTHERN OREGON COAST
AT 2 AM THIS MORNING. AMSU SHOWS TROPICAL PRECIPITABLE WATER AROUND
AN INCH WITH THE FRONT. AN UPPER LEVEL JET POINTED TOWARDS SOUTHERN
OREGON WILL PROVIDE ENOUGH LIFT TO TAP INTO THIS MOISTURE...RESULTING
IN LIGHT RAIN OVER MUCH OF THE REGION TODAY. THE FRONT SHOULD MOVE
ACROSS NW OREGON THIS AFTERNOON WITH ISOLATED TO SCATTERED
POST-FRONTAL SHOWERS TONIGHT.
SHOWERS OVER THE HIGHER TERRAIN WILL LIKELY PERSIST THROUGH SUNDAY
MORNING...BUT OTHERWISE DRY WEATHER CAN BE EXPECTED SUNDAY AS HIGH
PRESSURE BUILDS OVER THE AREA. SUNDAY MORNING WILL LIKELY BE CLOUDY
WITH PARTIAL CLEARING IN THE AFTERNOON...LEADING TO INLAND DAYTIME
HIGHS IN THE MID TO UPPER 60S AND COASTAL HIGHS IN THE UPPER
50S...SLIGHTLY BELOW THE SEASONAL NORMAL.
HIGH PRESSURE MAINTAIN DRY WEATHER FOR MONDAY WHICH WILL LIKELY BE
THE WARMEST DAY OF THE WEEK. INCREASED SUNSHINE SHOULD WARM INTERIOR
TEMPERATURES TO SLIGHTLY ABOVE NORMAL...LOW 70S AND COASTAL AREAS TO
NEAR NORMAL...LOWER 60S.
AN UPPER LEVEL LOW WILL APPROACH MONDAY NIGHT AND BRING A RETURN OF
SHOWERS AND MUCH COOLER WEATHER TO THE REGION. MODELS HAVE BACKED OFF
THE TIMING OF THE ONSET OF RAIN AROUND 12 HOURS. THE COLDEST AIR
ASSOCIATED WITH THE LOW WILL BEGIN MOVING OVER THE AREA TUESDAY NIGHT
AND SNOW LEVELS SHOULD LOWER TO AROUND 3500 TO 4000 FEET.
.LONG TERM...WEDNESDAY THROUGH FRIDAY...A COLD CLOSED LOW WILL
CONTINUE UNSETTLED WEATHER WITH UNSEASONAL COLD TEMPERATURES
WEDNESDAY...WITH RECORD LOW MAXIMUM TEMPERATURES POSSIBLE. WEDNESDAY
WILL BE THE COLDEST DAY OF THE WORK WEEK. TEMPERATURES WILL REMAIN
BELOW THE SEASONAL NORMALS THURSDAY AND FRIDAY AS A COUPLE OF
SHORTWAVE TROUGHS WILL CONTINUE SHOWERY AND COOL CONDITIONS.
&&
.AVIATION...A FRONT WILL APPROACH THE AREA THIS MORNING WITH CIGS
GRADUALLY LOWERING...WITH MVFR AND OCCASIONAL RAIN INCREASING BETWEEN
10Z AND 14Z. FRONT IS FAST MOVING...SO RETURN TO VFR LIKELY
BETWEEN 19Z AND 22Z...FIRST ON COAST AND LATER INLAND AS THE FRONT
SWEEPS EAST OF THE CASCADES BY MID AFTERNOON.
KPDX AND APPROACHES...VFR CONDITIONS FOR THE NEXT COUPLE OF HOURS.
AREAS OF MVFR CIGS DOWN NEAR 2500 FT INCREASE BETWEEN 12Z AND 15Z.
FRONT WILL PUSH ACROSS KPDX OPS AREA BETWEEN 20Z AND 22Z...WITH
RETURN TO VFR WITH SCATTERED SHOWERS.
&&
.MARINE...A FRONT WILL PUSH ACROSS THE COASTAL WATERS THIS
MORNING...THEN INLAND IN THE AFTERNOON. WINDS NOT ALL THAT
IMPRESSIVE BUT THERE SEEMS SO BE ENOUGH GRADIENT TO POP GUSTS 20
TO 25 KT THIS MORNING. SO WILL MAINTAIN CURRENT SMALL CRAFT
ADVISORY. OTHERWISE...WINDS TURN W TO NW BEHIND THE FRONT IN THE
AFTERNOON AND BEGIN TO EASE.
HIGH PRES WILL BUILD OVER THE NE PAC SUN INTO EARLY NEXT WEEK.
THIS WILL KEEP NW WINDS 10 TO 15 KT THROUGH MUCH OF THE COMING
WEEK...THOUGH MAY BRIEFLY GET 20 TO 25 KT GUSTS MON AFTERNOON INTO
THE EVENING.
SEAS REMAIN AT 5 TO 6 FT FOR INTO EARLY NEXT WEEK. MAY SEE SEAS
BUILD UP AND BECOME CHOPPY AT TIMES WITH THE BRISK NW WINDS ON THE
CENTRAL OREGON COASTAL WATERS NEXT WEEK.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS FROM 6 AM TO NOON
PDT TODAY FOR ALL COASTAL WATERS.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
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 180305
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
800 PM PDT FRI MAY 17 2013
.SYNOPSIS...SCATTERED SHOWERS WILL SHIFT INTO THE CASCADES THIS
EVENING AS WEAK SURFACE HIGH PRESSURE BUILDS INTO OREGON AND SW
WASHINGTON. THE NEXT PACIFIC SYSTEM WILL MOVE IN FOR SATURDAY...
BRINGING A PERIOD OF STEADY LIGHT RAIN SATURDAY FOLLOWED BY
DECREASING SHOWERS SATURDAY NIGHT AND SUNDAY. DRIER WEATHER IS
EXPECTED SUN NIGHT/MON... BUT IT IS LOOKING MORE LIKELY THAT A COOL
AND UNSETTLED PATTERN WILL SET UP OVER THE PACIFIC NORTHWEST FOR THE
MIDDLE OF NEXT WEEK.
&&
.SHORT TERM...TONIGHT THROUGH MONDAY...THE BACK EDGE OF SLOW MOVING
SHOWER ACTIVITY HAS SHIFTED INTO THE FOOTHILLS AND CASCADES AS HIGH
PRESSURE NOSES INTO NW OREGON AND SW WASHINGTON. HIGH PRESSURE WILL
REMAIN IN PLACE FOR THE REMAINDER OF THE EVENING AND INTO THE EARLY
OVERNIGHT HOURS...THUS EXPECT MOST AREAS OUTSIDE OF THE CASCADES AND
EVENTUALLY THE COAST TO REMAIN DRY UNTIL LATE TONIGHT.
A GRADUAL END TO SHOWER ACTIVITY HAS OCCURRED BUT MANY AREAS WILL
REMAIN MOSTLY CLOUDY DUE TO THE MOIST LOW LEVEL AIR MASS. THE
EXCEPTION WILL BE IN LEE OF THE COAST RANGE FOR THE REMAINDER OF THE
EVENING. NAM CROSS SECTIONS THROUGH THE WILLAMETTE VALLEY SEEM TO
SUPPORT THIS THINKING. EITHER WAY...IT WILL NOT BE LONG BEFORE HIGHER
CLOUDS BEGIN TO MOVE IN AHEAD OF OUR NEXT SYSTEM NOW SHOWN INSIDE
130W ON IR/WV SATELLITE IMAGERY. KMD
REST OF THE SHORT TERM FORECAST DISCUSSION UNCHANGED...STILL LOOKS
LIKE A DECENT CHANCE FOR RAIN THROUGHOUT THE DISTRICT SATURDAY AS
THAT MODEST FRONTAL SYSTEM MOVES ONSHORE. THERE WILL BE SOME WEAK
ISENTROPIC LIFT AHEAD OF THIS SYSTEM...SO JUST ABOUT EVERYONE SHOULD
GET SOME LIGHT RAIN. ONLY MODEST OROGRAPHIC ENHANCEMENT WITH 15-25
KT SW 850 MB WINDS...SO EXPECT RAIN TOTALS TO RANGE FROM 0.10-0.25
INCH IN THE VALLEYS AND 0.50 TO LOCALLY 1 INCH IN THE HIGHER
TERRAIN. RAIN WILL TAPER TO SHOWERS SATURDAY NIGHT WITH A FEW
LINGERING INTO SUNDAY...MAINLY OVER THE HIGHER TERRAIN.
TEMPERATURES WILL HOVER NEAR OR A LITTLE BELOW NORMAL THROUGH THE
WEEKEND. SNOW LEVELS SHOULD REMAIN ABOVE THE PASSES THROUGHOUT THE
WEEKEND...BUT MAY GET AS LOW AS 4500-5000 FT AT TIMES. MONDAY APPEARS
TO BE A DRIER DAY WITH MILD TEMPS AS A SHORTWAVE RIDGE MOVES ACROSS
THE PACIFIC NORTHWEST...BUT THIS WILL BE BRIEF AS THE NEXT SYSTEM
LOOMS FOR TUESDAY AND MIDWEEK. WEAGLE
.LONG TERM...MONDAY EVENING THROUGH FRIDAY...COLD CLOSED LOW
PRESSURE SYSTEM WILL PUSH ONSHORE MONDAY NIGHT...BRINGING RAIN AND
MUCH COOLER TEMPERATURES TO THE AREA. THIS LOW WILL LINGER OVER THE
PAC NW TUESDAY AND MUCH OF THE DAY WEDNESDAY...WITH RECORD LOW
MAXIMUM TEMPERATURES POSSIBLE ON WEDNESDAY. BY THURSDAY MODELS
DISAGREE ON WHERE THE LOW WILL PROPAGATE...BUT THE OVERALL TREND IS
FOR SHOWERY AND COOL CONDITIONS TO PERSIST THROUGH THE END OF THE
WEEK. BURGESS
&&
.AVIATION...AIR MASS STABILIZING THIS EVENING...AS MORE STABLE AIR
MASS SPREADS INTO THE REGION. SKIES REMAIN VFR THIS EVENING...WITH
WORST CONDITIONS AGAINST THE CASCADES. AS FRONT APPROACHES...CIGS
GRADUALLY LOWER LATE TONIGHT...WITH MVFR AND OCCASIONAL RAIN
INCREASING BETWEEN 10Z AND 14Z SAT. FRONT IS FAST MOVING...SO
RETURN TO VFR LIKELY BETWEEN 19Z AND 22Z...FIRST ON COAST AND
LATER INLAND AS THE FRONT SWEEPS EAST OF THE CASCADES BY MID
AFTERNOON.
KPDX AND APPROACHES...VFR TONIGHT. AREAS OF MVFR CIGS DOWN NEAR
2500 FT INCREASE BETWEEN 12Z AND 15Z. MVFR WITH RAIN DOMINATES
SAT AM. FRONT WILL PUSH ACROSS KPDX OPS AREA BETWEEN 20Z AND
22Z...WITH RETURN TO VFR WITH SCATTERED SHOWERS.ROCKEY.
&&
.MARINE...WINDS WILL GRADUALLY TURN MORE SOUTHERLY TONIGHT AS
ANOTHER FRONT APPROACHES. THIS FRONT WILL PUSH ACROSS THE COASTAL
WATERS SAT AM...THEN INLAND IN THE AFTERNOON. WINDS NOT ALL THAT
IMPRESSIVE BUT SEEMS THAT BE ENOUGH GRADIENT TO POP GUSTS 20 TO 25
KT SAT AM. SO WILL PUT UP SMALL CRAFT ADVISORY FOR THAT TIME
FRAME. OTHERWISE...WINDS TURN W TO NW BEHIND THE FRONT IN THE
AFTERNOON AND BEGIN TO EASE.
HIGH PRES WILL BUILD OVER THE NE PAC FOR SUN INTO EARLY NEXT WEEK.
THIS WILL KEEP NW WINDS 10 TO 15 KT THROUGH MUCH OF THE COMING
WEEK...THOUGH MAY BRIEFLY GET 20 TO 25 KT GUSTS MON AFTERNOON INTO
THE EVENING.
SEAS REMAIN AT 5 TO 6 FT FOR INTO EARLY NEXT WEEK. MAY SEE SEAS
BUILD UP AND BECOME CHOPPY AT TIMES WITH THE BRISK NW WINDS ON THE
CENTRAL OREGON COASTAL WATERS NEXT WEEK. ROCKEY.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS SAT AM ON ALL COASTAL WATERS.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
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 172141
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
240 PM PDT FRI MAY 17 2013
.SYNOPSIS...SCATTERED SHOWERS WILL GRADUALLY DECREASE THIS EVENING AS
WEAK SURFACE HIGH PRESSURE BUILDS INTO OREGON AND SW WASHINGTON. THE
NEXT PACIFIC SYSTEM WILL MOVE IN FOR SATURDAY...PROBABLY BRINGING A
PERIOD OF STEADY LIGHT RAIN SATURDAY FOLLOWED BY DECREASING SHOWERS
SATURDAY NIGHT AND SUNDAY. DRIER WEATHER IS EXPECTED SUN NIGHT/MON...
BUT IT IS LOOKING MORE LIKELY THAT A COOL AND UNSETTLED PATTERN WILL
SET UP OVER THE PACIFIC NORTHWEST FOR THE MIDDLE OF NEXT WEEK.
&&
.SHORT TERM...TONIGHT THROUGH MONDAY...A WEAK UPPER LEVEL TROUGH
CONTINUES TO GENERATE SCATTERED SHOWERS ACROSS THE FORECAST AREA THIS
AFTERNOON. THIS INSTABILITY IS PRETTY MUCH ALL SURFACE BASED BUT VERY
SHALLOW...WITH A CAPPING INVERSION IN PLACE AROUND 10KFT. WHILE THE
SHOWERS ARE NOT DEEP ENOUGH TO PRODUCE LIGHTNING...THE MIXED LAYER IS
STILL MOISTURE RICH. SO THERE STILL COULD BE SOME BRIEF HIT AND MISS
DOWNPOURS THROUGH THE RUSH HOUR COMMUTE.
SUBSIDENCE WILL INCREASE THIS EVENING AS SURFACE HIGH PRESSURE BUILDS
INTO OREGON. THIS SHOULD BRING A GRADUAL END TO SHOWER ACTIVITY BUT
IT WILL PROBABLY REMAIN CLOUDY DUE TO THE MOIST LOW LEVEL AIR MASS.
NAM CROSS SECTIONS THROUGH THE WILLAMETTE VALLEY SEEM TO SUPPORT THIS
THINKING. EITHER WAY...IT WILL NOT BE LONG BEFORE HIGHER CLOUDS BEGIN
TO MOVE IN AHEAD OF OUR NEXT SYSTEM NOW SHOWN APPROACHING 130W ON
IR/WV SATELLITE IMAGERY.
STILL LOOKS LIKE A DECENT CHANCE FOR RAIN THROUGHOUT THE DISTRICT
SATURDAY AS THAT MODEST FRONTAL SYSTEM MOVES ONSHORE. THERE WILL BE
SOME WEAK ISENTROPIC LIFT AHEAD OF THIS SYSTEM...SO JUST ABOUT
EVERYONE SHOULD GET SOME LIGHT RAIN. ONLY MODEST OROGRAPHIC
ENHANCEMENT WITH 15-25 KT SW 850 MB WINDS...SO EXPECT RAIN TOTALS TO
RANGE FROM 0.10-0.25 INCH IN THE VALLEYS AND 0.50 TO LOCALLY 1 INCH
IN THE HIGHER TERRAIN. RAIN WILL TAPER TO SHOWERS SATURDAY NIGHT WITH
A FEW LINGERING INTO SUNDAY...MAINLY OVER THE HIGHER TERRAIN.
TEMPERATURES WILL HOVER NEAR OR A LITTLE BELOW NORMAL THROUGH THE
WEEKEND. SNOW LEVELS SHOULD REMAIN ABOVE THE PASSES THROUGHOUT THE
WEEKEND...BUT MAY GET AS LOW AS 4500-5000 FT AT TIMES. MONDAY APPEARS
TO BE A DRIER DAY WITH MILD TEMPS AS A SHORTWAVE RIDGE MOVES ACROSS
THE PACIFIC NORTHWEST...BUT THIS WILL BE BRIEF AS THE NEXT SYSTEM
LOOMS FOR TUESDAY AND MIDWEEK. WEAGLE
.LONG TERM...MONDAY EVENING THROUGH FRIDAY...COLD CLOSED LOW
PRESSURE SYSTEM WILL PUSH ONSHORE MONDAY NIGHT...BRINGING RAIN AND
MUCH COOLER TEMPERATURES TO THE AREA. THIS LOW WILL LINGER OVER THE
PAC NW TUESDAY AND MUCH OF THE DAY WEDNESDAY...WITH RECORD LOW
MAXIMUM TEMPERATURES POSSIBLE ON WEDNESDAY. BY THURSDAY MODELS
DISAGREE ON WHERE THE LOW WILL PROPAGATE...BUT THE OVERALL TREND IS
FOR SHOWERY AND COOL CONDITIONS TO PERSIST THROUGH THE END OF THE
WEEK. BURGESS
&&
.AVIATION...SHOWER ACTIVITY HAS PICKED UP THIS AFTERNOON DUE TO
AFTERNOON HEATING AND INCREASING ONSHORE FLOW INTO THE COAST RANGE
THIS IS TRIGGERING SHOWERS IN THE ELEVATED MOUNTAIN TERRAIN THAT ARE
DRIFTING INTO THE INTERIOR LOWLANDS. EXPECT THIS SHOWER ACTIVITY
TO CONTINUE THROUGH THE AFTERNOON...ALTHOUGH VFR CONDITIONS ARE
EXPECTED TO CONTINUE. SHOWERS WILL DIMINISH THIS EVENING AS TEMPS
COOL AND THE UPPER LEVEL TROUGH AXIS PUSHES FURTHER EAST OF THE
AREA. MVFR CIGS WILL BEGIN TO SPREAD INTO THE COAST OVERNIGHT...
POTENTIALLY PUSHING INTO SOME INLAND SITES TOWARDS DAYBREAK AS WELL.
A FRONTAL PASSAGE WILL BRING LIGHT RAIN TO THE REGION DURING THE DAY
TOMORROW. EXPECT CONDITIONS WILL BE IN AND OUT OF MVFR THROUGH THE
DAY.
KPDX AND APPROACHES...VFR CIGS THROUGH TONIGHT. SCATTERED SHOWER
ACTIVITY IS EXPECTED THROUGH THE AFTERNOON...BEFORE DIMINISHING THIS
EVENING. THERE IS A CHANCE OF MVFR CIGS BY SUNRISE SATURDAY. A
FRONT WILL PUSH INLAND LATER IN THE MORNING...WITH A MIX OF VFR AND
MVFR EXPECTED THROUGH THE DAY IN LIGHT RAIN. PYLE
&&
.MARINE...WINDS WILL REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS
THROUGH TONIGHT. A FRONTAL BOUNDARY WILL PASS THROUGH THE WATERS
TOMORROW...BRINGING SOME STRONGER PREFRONTAL SW WINDS. THE FCST
MODELS ARE INDICATING THAT GUSTY WINDS WILL NOT BE QUITE WIDESPREAD
OR FREQUENT ENOUGH FOR A SMALL CRAFT ADVISORY. HOWEVER...THERE IS THE
POTENTIAL FOR A BIT OF A COASTAL JET FORMING IN THE NEARSHORE WATERS
DURING THE LATE MORNING/EARLY AFTERNOON HRS. SO A FEW GUSTS UP INTO
THE MID 20 KT RANGE ARE POSSIBLE. NORTHWEST WINDS WILL THEN
PREDOMINATE THE REMAINDER OF THE WEEKEND AND MUCH OF NEXT WEEK. A
SMALL CRAFT ADVISORY MAY BE REQUIRED FOR MONDAY AFTERNOON OR EVENING
TIME FRAME.
SEAS ARE FORECAST TO REMAIN AROUND 5 OR 6 FT FOR SEVERAL DAYS. WE
MAY SEE SEAS REACH 10 FT NEXT WEEK DUE TO THE BRISK NORTHWEST
WINDS. PYLE
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...NONE.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
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 171602
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
902 AM PDT FRI MAY 17 2013
.SYNOPSIS...SCATTERED SHOWERS AND SUNBREAKS ARE EXPECTED TODAY AS A
WEAK UPPER LEVEL TROUGH LINGERS OVER THE PACIFIC NORTHWEST. SURFACE
HIGH PRESSURE MAY BRING A BRIEF BREAK IN THE SHOWERS TONIGHT. THE
NEXT PACIFIC SYSTEM WILL MOVE IN SATURDAY...PROBABLY BRINGING A
PERIOD OF STEADY LIGHT RAIN SATURDAY FOLLOWED BY DECREASING SHOWERS
SATURDAY NIGHT AND SUNDAY. DRIER WEATHER IS EXPECTED SUN NIGHT/MON...
BUT IT IS LOOKING MORE LIKELY THAT A COOL AND UNSETTLED PATTERN WILL
SET UP OVER THE PACIFIC NORTHWEST FOR THE MIDDLE OF NEXT WEEK.
&&
.SHORT TERM...TODAY THROUGH SUNDAY...A WEAK UPPER LEVEL TROUGH
EXTENDS FROM VANCOUVER ISLAND SOUTHEAST ACROSS WASHINGTON...OREGON
AND NEVADA THIS MORNING. THE BETTER DEFINED AREA OF LOW PRESSURE
ASSOCIATED WITH THIS SYSTEM APPEARS TO BE NEAR LAS VEGAS...WITH AN
ATTENDANT COLD FRONT PUSHING ACROSS THE US/MEXICO BORDER NEAR SAN
DIEGO AND TIJUANA. SO THE BEST ENERGY WITH THIS SYSTEM IS WELL TO OUR
SOUTH...JUST SOME LINGERING MOISTURE AND WEAK/SHALLOW INSTABILITY FOR
SOME SCATTERED SHOWERS ACROSS OUR FORECAST AREA TODAY. 12Z KSLE
SOUNDING SHOWS A DISTINCT CAP NEAR 700 MB WHICH WILL LIMIT SFC BASED
CONVECTION TO AROUND 10KFT...NOT NEARLY ENOUGH FOR THUNDER. TEMPS
TODAY WILL BE SEASONABLE IN THE MID TO UPPER 60S.
SUBSIDENCE WILL INCREASE THIS EVENING AS SURFACE HIGH PRESSURE BUILDS
INTO OREGON. THIS SHOULD BRING A GRADUAL END TO SHOWER ACTIVITY BUT
IT WILL PROBABLY REMAIN CLOUDY DUE TO THE MOIST LOW LEVEL AIR MASS.
NAM CROSS SECTIONS THROUGH THE WILLAMETTE VALLEY SEEM TO SUPPORT THIS
THINKING. EITHER WAY...IT WILL NOT BE LONG BEFORE HIGHER CLOUDS BEGIN
TO MOVE IN AHEAD OF OUR NEXT SYSTEM NOW SHOWN CROSSING 140W-135W ON
IR IMAGERY.
STILL LOOKS LIKE A DECENT CHANCE FOR RAIN THROUGHOUT THE DISTRICT
SATURDAY AS THAT MODEST FRONTAL SYSTEM MOVES ONSHORE. THERE WILL BE
SOME WEAK ISENTROPIC LIFT AHEAD OF THIS SYSTEM...SO JUST ABOUT
EVERYONE SHOULD GET SOME LIGHT RAIN. ONLY MODEST OROGRAPHIC
ENHANCEMENT WITH 15-25 KT SW 850 MB WINDS...SO EXPECT RAIN TOTALS TO
RANGE FROM 0.10-0.25 INCH IN THE VALLEYS AND 0.50 TO LOCALLY 1 INCH
IN THE HIGHER TERRAIN. RAIN WILL TAPER TO SHOWERS SATURDAY NIGHT WITH
A FEW LINGERING INTO SUNDAY...MAINLY OVER THE HIGHER TERRAIN.
TEMPERATURES WILL HOVER NEAR OR A LITTLE BELOW NORMAL THROUGH THE
WEEKEND. SNOW LEVELS SHOULD REMAIN ABOVE THE PASSES THROUGHOUT THE
WEEKEND...BUT MAY GET AS LOW AS 4500-5000 FT AT TIMES. WEAGLE
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...SUNDAY NIGHT
THROUGH THURSDAY...AFTER A BRIEF BREAK OF POTENTIALLY SUNNY AND
SEASONABLE WEATHER MONDAY...IT APPEARS AN EXTENDED COOL AND
UNSETTLED PERIOD IS BECOMING INCREASINGLY LIKELY FOR MIDWEEK. MODELS
ARE SHOWING RELATIVELY GOOD AGREEMENT THAT A COLD AND CLOSED UPPER
LOW WILL DIG DOWN FROM ALASKA...SETTLING SOMEWHERE NEAR THE PAC NW
TUE AND LINGERING THROUGH THURSDAY. COLD AIR ALOFT WILL KEEP THE AIR
MASS UNSTABLE...WITH COOL SHOWERY WEATHER AND POSSIBLY EVEN A
THUNDERSTORM OR TWO DEPENDING ON HOW THINGS EVOLVE.
FAIRLY HIGH DEGREE OF CONFIDENCE OF BELOW NORMAL TEMPS DURING THIS
PERIOD ALONG WITH HIT AND MISS SHOWERS. SNOW LEVELS MAY VERY WELL GET
BELOW THE PASSES...BUT WE WILL PLAY IT CONSERVATIVE FOR NOW WITH SNOW
LEVELS BOTTOMING OUT AROUND 4000-4500 FT MIDWEEK. IF MODELS CONTINUE
TO BRING THE CENTER OF THE COLD POOL OVER THE PAC NW...THESE SNOW
LEVELS WILL NEED TO COME DOWN A BIT AND POSSIBLY AS LOW AS 2000-3000
FEET. WEAGLE
&&
.AVIATION...AN OFFSHORE LOW CONTINUES TO SPREAD SOME SHOWERS OVER
THE S WA CASCADES AND ALONG THE S WA/N OR COAST THIS MORNING. THE
FLOW WILL TURN MORE SOUTHWESTERLY AND WESTERLY THIS AFTERNOON
WITH A FEW SHOWERS SPREADING OFF THE HIGHER TERRAIN OVER THE
VALLEYS. A FEW POCKETS OF MVFR CIGS REMAIN THIS MORNING...BUT
EXPECT WIDESPREAD VFR CONDITIONS TO DEVELOP SHORTLY AND CONTINUE
THROUGH THIS EVENING. THE SHOWER ACTIVITY SHOULD DIMINISH THIS
EVENING AS THE UPPER LEVEL TROUGH AXIS PUSHES EAST OF THE
CASCADES. WITH THE ONSHORE FLOW...EXPECT MVFR CIGS TO SPREAD BACK
INTO THE COAST OVERNIGHT...POSSIBLY PUSHING INLAND AS WELL.
KPDX AND APPROACHES...VFR CIGS TODAY. SOME LIGHT SHOWER ACTIVITY
MAY AFFECT THE TERMINAL AT TIMES DURING THE DAYTIME HOURS. SHOWERS
WILL DIMINISH THIS EVENING. THERE IS A CHANCE OF MVFR CIGS BY
SUNRISE SATURDAY. PYLE
&&
.MARINE...WINDS WILL REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS
THROUGH TONIGHT AS ONE SYSTEM WEAKENS AND MOVES EAST AND BEFORE THE
NEXT SYSTEM ARRIVES. PREFRONTAL SOUTHERLY SMALL CRAFT ADVISORY WINDS
ARE POSSIBLE BY EARLY SATURDAY AND THROUGH MOST OF SATURDAY.
NORTHWEST WINDS WILL THEN PREDOMINATE THE REMAINDER OF THE WEEKEND
AND MUCH OF NEXT WEEK...AND MAY REQUIRE A SMALL CRAFT ADVISORY
AT TIMES NEXT WEEK.
SEAS ARE FORECAST TO REMAIN AROUND 5 OR 6 FT FOR SEVERAL DAYS...
POSSIBLY 7 FT OR SO WITH THE FRONT SATURDAY. WE MAY SEE SEAS
REACH 10 FT NEXT WEEK DUE TO THE BRISK NORTHWEST WINDS. PYLE/PT
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...NONE.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
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 170946
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
245 AM PDT FRI MAY 17 2013
.SYNOPSIS...A FEW SHOWERS WILL CONTINUE TODAY ESPECIALLY IN THE
CASCADES AS A WEAK SYSTEM SLIDES TO THE EAST. TRANSITORY HIGH
PRESSURE MAY BRING A BRIEF BREAK IN THE SHOWERS TONIGHT BEFORE THE
NEXT SYSTEM BRINGS ANOTHER DECENT CHANCE FOR RAIN SATURDAY AND
LINGERING SHOWERS SUNDAY. DRIER WEATHER IS EXPECTED SUN NIGHT/MON...
BUT IT IS LOOKING MORE LIKELY THAT A COOL AND UNSETTLED PATTERN WILL
SET UP OVER THE PACIFIC NORTHWEST FOR THE MIDDLE OF NEXT WEEK.
&&
.SHORT TERM...SHOWERS WILL CONTINUE TODAY ESPECIALLY ACROSS THE
CASCADES AS A WEAK SYSTEM SLIDES TO THE EAST. MODEL SOUNDINGS SHOW
SHALLOW INSTABILITY UP TO 600-700 MB. THIS SHOULD GREATLY LIMIT
SHOWER POTENTIAL TODAY DESPITE A LITTLE MORE SUNSHINE...BUT THERE
WILL STILL BE ENOUGH INSTABILITY FOR SCATTERED SHOWERS THROUGHOUT
THE DAY. THESE WILL DISSIPATE THIS EVENING AS HIGH PRESSURE BRIEFLY
BUILDS OVERHEAD. HOWEVER...THE NEXT SYSTEM NOW NEAR 150W WILL LIKELY
SPREAD RAIN BACK ACROSS THE DISTRICT SATURDAY. QPF SHOULD BE MODEST
WITH AROUND 0.25 INCH IN THE VALLEYS AND UP TO 1 INCH IN THE HIGHER
TERRAIN. RAIN WILL TAPER TO SHOWERS SATURDAY NIGHT WITH A FEW
LINGERING INTO SUNDAY...MAINLY OVER THE HIGHER TERRAIN.
TEMPERATURES WILL HOVER A LITTLE BELOW NORMAL THROUGH THE WEEKEND.
SNOW LEVELS SHOULD REMAIN ABOVE THE PASSES THROUGHOUT THE
WEEKEND...BUT MAY GET AS LOW AS 4500-5000 FT AT TIMES.
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...SUNDAY NIGHT
THROUGH THURSDAY...AFTER A BRIEF BREAK OF POTENTIALLY SUNNY AND
SEASONABLE WEATHER MONDAY...IT APPEARS AN EXTENDED COOL AND
UNSETTLED PERIOD IS BECOMING INCREASINGLY LIKELY FOR MIDWEEK. MODELS
ARE SHOWING RELATIVELY GOOD AGREEMENT THAT A COLD AND CLOSED UPPER
LOW WILL DIG DOWN FROM ALASKA...SETTLING SOMEWHERE NEAR THE PAC NW
TUE AND LINGERING THROUGH THURSDAY. COLD AIR ALOFT WILL KEEP THE AIR
MASS UNSTABLE...WITH COOL SHOWERY WEATHER AND POSSIBLY EVEN A
THUNDERSTORM OR TWO DEPENDING ON HOW THINGS EVOLVE.
FAIRLY HIGH DEGREE OF CONFIDENCE OF BELOW NORMAL TEMPS DURING THIS
PERIOD ALONG WITH HIT AND MISS SHOWERS. SNOW LEVELS MAY VERY WELL GET
BELOW THE PASSES...BUT WE WILL PLAY IT CONSERVATIVE FOR NOW WITH SNOW
LEVELS BOTTOMING OUT AROUND 4000-4500 FT MIDWEEK. IF MODELS CONTINUE
TO BRING THE CENTER OF THE COLD POOL OVER THE PAC NW...THESE SNOW
LEVELS WILL NEED TO COME DOWN A BIT AND POSSIBLY AS LOW AS 2000-3000
FEET. WEAGLE
&&
.AVIATION...CONSIDERABLE CLOUDS WILL CONTINUE OVER SOUTHWEST
WASHINGTON AND NORTHWEST OREGON TODAY AS A WEAK LOW CONTINUES OFF
THE COAST AND SLOWLY FILLS. THE SOUTHEAST FLOW AROUND THIS LOW WAS
SPREADING SHOWERS FROM CENTRAL OREGON ACROSS THE NORTH OREGON
CASCADES INTO SOUTHWEST WASHINGTON...AND WILL CONTINUE UNTIL AFTER
SUNRISE UNTIL THE MAIN UPPER TROUGH MOVES FARTHER EAST. THE FLOW
WILL TURN MORE SOUTHWESTERLY AND WESTERLY THIS AFTERNOON WITH A
FEW SHOWERS SPREADING OFF THE HIGHER TERRAIN OVER THE VALLEYS.
LOOK FOR VFR CIGS TODAY WITH SOME MVFR CIGS MIXED IN THIS MORNING.
EXPECT MOSTLY VFR CIGS TONIGHT WITH DECREASING SHOWERS BUT CANNOT
RULE OUT SOME PATCHES OF MVFR CIGS BY SUNRISE SATURDAY.
KPDX AND APPROACHES...VFR CIGS TODAY WITH POSSIBLE MVFR CIGS THIS
MORNING. SOME SHOWERS SPREADING IN FROM THE SOUTHEAST MAY AFFECT
THE AIRPORT AT TIMES THIS MORNING...AND ESPECIALLY THE EASTERN
APPROACHES. THE FLOW WILL TURN MORE WESTERLY THIS AFTERNOON AND
COULD STILL SEE A SHOWER OR TWO DRIFT OFF THE COAST RANGE AND
AFFECT THE AIRPORT THIS AFTERNOON AND EVENING. THERE IS A CHANCE
OF MVFR CIGS BY SUNRISE SATURDAY. PT
&&
.MARINE...WINDS WILL REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS
TODAY AND MOST OF TONIGHT AS ONE SYSTEM WEAKENS AND MOVES EAST AND
BEFORE THE NEXT SYSTEM ARRIVES. PREFRONTAL SOUTHERLY SMALL CRAFT
ADVISORY WINDS ARE POSSIBLE BY EARLY SATURDAY AND THROUGH MOST OF
SATURDAY. NORTHWEST WINDS WILL THEN PREDOMINATE THE REMAINDER OF
THE WEEKEND AND MUCH OF NEXT WEEK...AND MAY REQUIRE A SMALL CRAFT
ADVISORY AGAIN ESPECIALLY NEXT WEEK.
SEAS ARE FORECAST TO REMAIN AROUND 5 OR 6 FT FOR SEVERAL DAYS...
POSSIBLY 7 FT OR SO WITH THE FRONT SATURDAY. WE MAY SEE SEAS
REACH 10 FT NEXT WEEK DUE TO THE BRISK NORTHWEST WINDS. PT
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...NONE.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
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.
| 
