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000
FXUS66 KPQR 040306
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
805 PM PDT TUE MAY  3 2016

.SYNOPSIS...SEEMS MORE LIKE MAY...WITH CLOUDS AND SOME SHOWERS. UPPER
LOW WILL CONTINUE PASSING TO OUR SOUTH OVER NEXT FEW DAYS.. THIS
KEEPS A THREAT OF SHOWERS ACROSS THE REGION. THEN HIGH PRES RETURNS
LATER FRI...WITH RETURN TO MILD AND DRY CONDITIONS. THIS DRY AND MILD
WEATHER LOOKS TO STRETCH INTO NEXT WEEK...WITH MORNING CLOUDS AND
AFTERNOON SUNSHINE.
&&

.SHORT TERM...(TODAY THROUGH FRI)...SHOWERS CURRENTLY MOVING
NORTHWARD...WITH A COUPLE EMBEDDED THUNDERSTORMS ALONG THE CASCADE
FOOTHILLS AND UP IN THE CASCADES. CHANCE OF THUNDER WILL DIMINISH
AFTER SUNSET THIS EVENING...SO THUNDERSTORMS OUT THERE NOW WILL
PROBABLY NOT MAKE IT UP INTO UP INTO WASHINGTON. OTHERWISE...WILL SEE
SHOWERS OVERNIGHT AS THE UPPER TROUGH OFFSHORE MAINTAINS SOUTHERLY
FLOW ALOFT. ALONG THE COAST A FEW SHOWERS ARE POSSIBLE WITH
OCCASIONAL DRIZZLE BEING OBSERVED CONTINUING OVERNIGHT.

.NO CHANGES TO REST OF DISCUSSION. PREVIOUS DISCUSSION FOLLOWS...
UPPER TROUGH OFFSHORE WILL SLOWLY PUSH EASTWARD OVER THE REGION
TONIGHT THROUGH THU. MAIN ENERGY ASSOCIATED WITH THE TROUGH WILL
REMAIN WELL SOUTH OF OUR AREA OVER NRN CALIF. BUT STILL CLOSE ENOUGH
TO KEEP THREAT OF SHOWERS OVER THE REGION THROUGH THU. BEST THREAT OF
SHOWERS LOOKS TO BE ON WED INTO WED EVENING. IN ADDITION...WILL TREND
WITH HIGHER POPS BASICALLY S OF A MT HOOD TO NEWPORT LINE.
AS UPPER TROUGH SHIFTS FURTHER EASTWARD LATER THU AND THU NIGHT...
WILL SEE DECREASING CHANCE OF SHOWERS.

HIGH PRES WILL BUILD OVER THE REGION ON FRI...WITH MORNING CLOUDS
GIVING WAY TO PARTLY TO MOSTLY SUNNY SKIES. NOT ALL THAT CONFIDENT
THAT WILL SEE ANY SHOWERS LEFT OVER THE REGION...SO WILL LOWER POPS
BACK TO 10 PCT OR LESS. IF ANYTHING WERE TO OCCUR...WOULD BE AN
ISOLATED SHOWER OR TWO OVER THE CASCADES. BUT WILL GO WITH TREND OF
DRY AND MILD TEMPERATURES...WITH 60S ALONG THE COAST AND BACK INTO
THE 70S OVER MUCH OF THE INTERIOR.    MCCOY/ROCKEY.


.LONG TERM......(FRI NIGHT THROUGH TUE)...OUR TREND OF CLOUDS/DAMP
WEEKDAYS AND SUNNY/MILD WEEKENDS CONTINUES. HIGH PRES WILL BUILD OVER
THE REGION...WITH MILD TEMPERATURES AND STABLE NW FLOW ALOFT. THIS
WILL KEEP A MORE JUNE LIKE PATTERN...WITH LATE NIGHT/AM CLOUDS THEN
MOSTLY CLEAR SKIES. WEAK FRONT WILL PASS ACROSS THE REGION ON
MON...BUT NOT MUCH IN WAY OF ANY RAIN THREAT. MAIN EFFECT WILL BE TO
INCREASE ONSHORE FLOW A BIT. SO MON WILL BE BIT COOLER...WITH MORE IN
WAY OF MORNING CLOUDS THEN PARTLY SUNNY SKIES.    ROCKEY.
&&

.AVIATION...INLAND AREAS WILL CONTINUE WITH VFR BUT WITH PLENTY
OF MID-LEVEL AND HIGH-LEVEL CLOUDS AND A FEW SHOWERS IN SOUTH
FLOW ALOFT. THERE IS A CHANCE OF A THUNDERSTORM NEAR THE CASCADES.
CIGS WILL PROBABLY NOT LOWER TO MVFR UNTIL LATER TONIGHT INLAND...
MAYBE NOT UNTIL 09Z TO 12Z. CIGS WILL PROBABLY LIFT INLAND TO VFR
WEDNESDAY AFTERNOON BUT A FEW SHOWERS ARE STILL POSSIBLE
ESPECIALLY NEAR THE CASCADES. COASTAL SITES ARE A MIXTURE OF IFR
AND MVFR CONDITIONS WITH SOME LIGHT SHOWERS OR LOCAL DRIZZLE...
LIFTING TO MAINLY MVFR WEDNESDAY AFTERNOON.

KPDX AND APPROACHES...VFR CONDITIONS WITH POSSIBLY AN ISOLATED
SHOWER TONIGHT. EXPECT MVFR CIGS TO POSSIBLY REACH THE AIRPORT
AROUND 12Z. EXPECT CIGS TO LIFT TO VFR WEDNESDAY AFTERNOON. PT
&&

.MARINE...NW TO N WINDS INCREASING TONIGHT AND CONTINUING WELL
INTO THE WEEKEND. WINDS HAVE REACHED SMALL CRAFT ADVISORY LEVELS
AT BUOY 89 ALREADY...AND SHOULD SPREAD ACROSS THE WATERS TONIGHT.
EXPECT SMALL CRAFT ADVISORY WINDS AT TIMES INTO THE WEEKEND.

SEAS ARE AROUND 6 FT THIS EVENING AND ARE FORECAST TO BUILD TO
AROUND 8 OR 9 FT BY LATER WEDNESDAY AND POSSIBLY NEAR 10 FT AFTER
THAT. THE NORTHWEST DRIVEN SEAS WILL TURN INTO FRESH SWELL WITH
SHORT PERIODS AND RESULTING IN CHOPPY OR SQUARE SEAS...AND WILL
CONTINUE THE SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS.

EXPECT BOTH SMALL CRAFT ADVISORIES TO BE EXTENDED FOR AT LEAST A
COUPLE OF MORE DAYS AS WE MOVE THROUGH THE WEEK. PT
&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 5 AM PDT THURSDAY FOR
     WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR FROM 10 TO
     60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 11 PM THIS EVENING
     TO 5 AM PDT THURSDAY FOR COASTAL WATERS FROM CAPE
     SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR WINDS FROM 11 PM THIS EVENING TO 5 AM
     PDT THURSDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
     FLORENCE OR OUT 10 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 2 PM TO
     6 PM PDT WEDNESDAY.

&&

$$

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 032112
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
211 PM PDT TUE MAY  3 2016

.SYNOPSIS...SEEMS MORE LIKE MAY...WITH CLOUDS AND SOME SHOWERS. UPPER
LOW WILL CONTINUE PASSING TO OUR SOUTH OVER NEXT FEW DAYS.. THIS
KEEPS A THREAT OF SHOWERS ACROSS THE REGION. THEN HIGH PRES RETURNS
LATER FRI...WITH RETURN TO MILD AND DRY CONDITIONS. THIS DRY AND MILD
WEATHER LOOKS TO STRETCH INTO NEXT WEEK...WITH MORNING CLOUDS AND
AFTERNOON SUNSHINE.
&&

.SHORT TERM...(TODAY THROUGH FRI)...
NOT A LOT OF CHANGE THIS AFTERNOON INTO EVENING...AS UPPER TROUGH
SITS OFFSHORE AND MAINTAINING SOUTHERLY FLOW OVER WESTERN OREGON AND
SW WASHINGTON. THIS SOUTHERLY FLOW WILL MAINTAIN INSTABILITY OVER THE
REGION. BUT NOT ALL THAT IMPRESSIVE CONSIDERING WHAT OCCURRED ON MON
EVENING. THIS SAID...WILL NOT MAKE MANY CHANGES TO THIS EVENING WITH
CHANCE OF SHOWERS...THOUGH WILL KEEP MUCH HIGHER THREAT OF SHOWERS
OVER THE CASCADES. AGAIN...JUST ENOUGH INSTABILITY THREAT OT MAINTAIN
CHANCE OF THUNDERSTORMS OVER THE CASCADES THIS EVENING. OTHERWISE...A
PLEASANT LATE AFTERNOON/EVENING FOR MOST OF REGION WITH LOW CLOUDS
AND EVEN OCCASIONAL DRIZZLE INCREASING ALONG THE COAST THIS EVENING.

UPPER TROUGH OFFSHORE WILL SLOWLY PUSH EASTWARD OVER THE REGION
TONIGHT THROUGH THU. MAIN ENERGY ASSOCIATED WITH THE TROUGH WILL
REMAIN WELL SOUTH OF OUR AREA OVER NRN CALIF. BUT STILL CLOSE ENOUGH
TO KEEP THREAT OF SHOWERS OVER THE REGION THROUGH THU. BEST THREAT OF
SHOWERS LOOKS TO BE ON WED INTO WED EVENING. IN ADDITION...WILL TREND
WITH HIGHER POPS BASICALLY S OF A MT HOOD TO NEWPORT LINE.
AS UPPER TROUGH SHIFTS FURTHER EASTWARD LATER THU AND THU NIGHT...
WILL SEE DECREASING CHANCE OF SHOWERS.

HIGH PRES WILL BUILD OVER THE REGION ON FRI...WITH MORNING CLOUDS
GIVING WAY TO PARTLY TO MOSTLY SUNNY SKIES. NOT ALL THAT CONFIDENT
THAT WILL SEE ANY SHOWERS LEFT OVER THE REGION...SO WILL LOWER POPS
BACK TO 10 PCT OR LESS. IF ANYTHING WERE TO OCCUR...WOULD BE AN
ISOLATED SHOWER OR TWO OVER THE CASCADES. BUT WILL GO WITH TREND OF
DRY AND MILD TEMPERATURES...WITH 60S ALONG THE COAST AND BACK INTO
THE 70S OVER MUCH OF THE INTERIOR.       ROCKEY.


.LONG TERM......(FRI NIGHT THROUGH TUE)...OUR TREND OF CLOUDS/DAMP
WEEKDAYS AND SUNNY/MILD WEEKENDS CONTINUES. HIGH PRES WILL BUILD OVER
THE REGION...WITH MILD TEMPERATURES AND STABLE NW FLOW ALOFT. THIS
WILL KEEP A MORE JUNE LIKE PATTERN...WITH LATE NIGHT/AM CLOUDS THEN
MOSTLY CLEAR SKIES. WEAK FRONT WILL PASS ACROSS THE REGION ON
MON...BUT NOT MUCH IN WAY OF ANY RAIN THREAT. MAIN EFFECT WILL BE TO
INCREASE ONSHORE FLOW A BIT. SO MON WILL BE BIT COOLER...WITH MORE IN
WAY OF MORNING CLOUDS THEN PARTLY SUNNY SKIES.    ROCKEY.
&&

.AVIATION...INLAND AREAS WILL CONTINUE WITH VFR BUT WITH PLENTY
OF MID-LEVEL AND HIGH-LEVEL CLOUDS IN SOUTH FLOW ALOFT. AFTERNOON
HEATING WILL LEAD TO A THREAT OF SHOWERS...PRIMARILY ALONG THE
CASCADES. COASTAL SITES WILL CONTINUE TO OSCILLATE BETWEEN VFR AND
MVFR CIGS. WILL LIKELY SEE A STRONG MARINE STRATUS PUSH INLAND
TONIGHT AND SHOULD SEE MVFR CIG AT ALL INLAND TAF SITES STARTING
AROUND 10Z. CONDITIONS RETURN TO VFR EVERYWHERE BETWEEN 15Z AND
18Z WED.

KPDX AND APPROACHES...PLENTY OF MID AND HIGH LEVEL CLOUDS THROUGH
TUE EVENING WITH A SLIM THREAT OF SHOWERS IN THE VICINITY. MVFR
CIGS WILL LIKELY PUSH UP THE COLUMBIA AND AFFECT THE TERMINAL
AFTER ABOUT 10Z...RETURNING TO VFR BY 18Z WED. BOWEN

&&

.MARINE...NW TO N WIND PATTERN RETURNING THIS AFTERNOON AND WILL
BE THE DOMINANT FEATURE OVER THE NEXT SEVERAL DAYS. LATEST MODELS
IN GOOD AGREEMENT SHOWING 20 TO 25 KT SUSTAINED SPEEDS DEVELOPING
OVER THE OUTER WATERS BY THIS EVENING AND CONTINUING THROUGH AT
LEAST THURSDAY BEFORE A POSSIBLE BREAK. WILL KEEP SMALL CRAFT
ADVISORY IN PLACE AS IS FOR NEARSHORE AND OFFSHORE WATERS.

SEAS CONTINUE TO BE GENERALLY 5 TO 7 FT. LATEST SPECTRAL GUIDANCE
SUGGEST SEAS WILL BECOME WIND WAVE DOMINATED THIS EVENING AND
THROUGH THE NEXT FEW DAYS. AS SUCH...SEAS WILL BECOME QUITE
CHOPPY AND SO HAVE ISSUED A SMALL CRAFT ADVISORY FOR SEAS FOR
SQUARE SEAS BEGINNING THIS EVENING. SEAS WILL LIKELY BE 7 TO 8 FT
AT 7 TO 8 SECONDS THROUGH THE REST OF THE WORKWEEK AND POSSIBLY
INTO THE WEEKEND. BOWEN

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS FROM 5 PM THIS AFTERNOON TO 5 AM
     PDT THURSDAY FOR WATERS FROM CAPE SHOALWATER WA TO
     FLORENCE OR FROM 10 TO 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 11 PM THIS EVENING
     TO 5 AM PDT THURSDAY FOR COASTAL WATERS FROM CAPE
     SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR WINDS FROM 11 PM THIS EVENING TO 5 AM
     PDT THURSDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
     FLORENCE OR OUT 10 NM.

&&

$$

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

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





000
FXUS66 KPQR 031620
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
918 AM PDT TUE MAY  3 2016

.SYNOPSIS...SLOW MOVING COLD FRONT INCHING TOWARD THE COAST WILL
CONTINUE TO BRING THE THREAT OF SHOWERS TO THE REGION THROUGH
WEDNESDAY...WITH A STRAY THUNDERSTORM POSSIBLE EACH DAY IN THE
CASCADES. AS LOW-LEVEL FLOW TURNS INCREASINGLY ONSHORE...EXPECT
COOLER TEMPERATURES TO SPREAD INLAND TODAY AND WEDNESDAY. DRYING
TREND IS EXPECTED LATER IN THE WEEK AS THE REMNANTS OF THE FRONT
REORGANIZE INTO A CUTOFF LOW OVER CALIFORNIA. THIS WILL BRING A
RETURN TO OFFSHORE FLOW...WITH WARM AND DRY WEATHER THIS WEEKEND AS
HIGH PRESSURE BUILDS INTO THE PACIFIC NORTHWEST.

&&
.SHORT TERM...TODAY THROUGH THU...NO CHANGES. AFTER YET ANOTHER DAY
OF RECORD BREAKING WARMTH FOR SOME...TODAY SHOULD BE A BIT COOLER
ACROSS SW WA/NW OR AS LOW-LEVEL FLOW TURNS INCREASINGLY ONSHORE. PRES
GRADIENTS HAVE FLIPPED AROUND TO ONSHORE OVER THE PAST FEW HOURS...
BOTH ON THE SYNOPTIC AND MESO SCALES. KTTD-KDLS WAS AT ABOUT +3 MB AS
OF 2 AM...WITH KOTH-KGEG GRADIENTS TURNING ONSHORE AS WELL. THIS
WILL USHER IN A COOLER AIR MASS FROM THE PACIFIC AND HIGHS TODAY
SHOULD BE A GOOD 10-20 DEGREES COOLER THAN MONDAY FOR INLAND
AREAS...AROUND 70 IN THE VALLEYS. STRENGTHENING HIGH PRESSURE OVER
THE NE PACIFIC WILL KEEP ONSHORE FLOW GOING THROUGH AT LEAST
THURSDAY...BRINGING TEMPERATURES DOWN CLOSER TO NORMAL WED/THU.

SHOWERS CONTINUE TO DEVELOP IN THE SHALLOW/WEAK INSTABILITY BETWEEN
700-500 MB THIS MORNING...BUT DESPITE BEING ELEVATED CONVECTION THE
TOPS ARE STILL GENERALLY NOT HIGH/COLD ENOUGH TO CAUSE THE REQUISITE
CHARGE SEPARATION FOR LIGHTNING. DECIDED TO LEAVE THUNDER OUT OF THE
FORECAST THIS MORNING...THOUGH A STRAY STRIKE OR TWO LIKE THE ONES
RECENTLY OBSERVED OVER THE STRAIT OF JUAN DE FUCA ARE NOT OUT OF THE
QUESTION ANYWHERE. MODEL SOUNDINGS GENERALLY SHOW LITTLE CHANGE OVER
THE NEXT 48 HOURS...WITH LIMITED INSTABILITY AT BEST ABOVE 500 MB.
SURFACE-BASED CONVECTION WILL BRING MAINLY AFTERNOON/EVENING SHOWERS
THROUGH WEDNESDAY...BUT ALSO APPEARS TOO SHALLOW FOR LIGHTNING WEST
OF THE CASCADES EITHER DAY.

THE REMNANTS OF OUR DYING COLD FRONT/UPPER TROUGH ARE PROGGED TO
REORGANIZE INTO A CUTOFF UPPER LOW OVER CALIFORNIA BY THE END OF THE
WEEK...WHILE MOST MODELS BUILD AN UPPER RIDGE ACROSS SOUTHERN BC AND
WASHINGTON. THIS WILL GRADUALLY BRING A RETURN TO DRIER OFFSHORE FLOW
ALOFT BY THE WEEKEND...WITH THURSDAY APPEARING TO BE THE BEGINNING OF
THAT TRANSITION. SHOULD SEE SHOWERS DIMINISH AND BECOME INCREASINGLY
CONFINED TO THE CASCADES THU/FRI AS A RESULT.  WEAGLE

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...(THU NIGHT
THROUGH MON)... MODELS REMAIN IN FAIR
AGREEMENT THROUGH THE EXTENDED PERIOD AS THE UPPER LEVEL LOW
CONTINUES TO ADVANCE INTO THE GREAT BASIN WHILE AN UPPER RIDGE
BEGINS TO NOSE INTO THE PACIFIC NORTHWEST FROM THE NORTHEAST
PACIFIC. THIS WILL BRING AN END TO THE SHOWER CHANCES FOR MUCH OF
THE AREA ON FRIDAY...THOUGH WILL MAINTAIN A SLIGHT CHANCE FOR
SHOWERS OVER THE SOUTHERN PORTIONS OF THE CASCADE ZONES.
TEMPERATURES WILL WARM INTO THE WEEKEND BACK ABOVE SEASONAL NORMS
AS HEIGHTS RISE AND THE AIR MASS WARMS.   CULLEN

&&

.AVIATION...INLAND AREAS WILL CONTINUE WITH VFR BUT WITH PLENTY
OF MID-LEVEL CLOUDS IN SOUTH FLOW ALOFT. AFTERNOON HEATING WILL
LEAD TO A THREAT OF SHOWERS...PRIMARILY ALONG THE CASCADES.
COASTAL SITES WILL CONTINUE TO OSCILLATE BETWEEN VFR AND MVFR FOR
BOTH CIGS AND VIS. MODELS SUGGEST MUCH DEEPER MARINE CLOUD
PENETRATION INLAND AFTER 06Z WED.

KPDX AND APPROACHES...VFR CONDITIONS THROUGH AT LEAST 07Z WED.
PLENTY OF MID AND HIGH LEVEL CLOUDS THROUGH TUE EVENING WITH A
SLIM THREAT OF SHOWERS TUE AFTERNOON AND EVENING IN THE VICINITY.
MVFR CIGS COULD UP THE COLUMBIA RIVER TO NEAR KPDX AFTER 06Z TO AS
LATE AS TO 18Z WED. BOWEN/WEISHAAR
&&

.MARINE...SOUTH WIND REVERSAL ALONG THE COAST EARLY THIS
MORNING...BUT MAX GUSTS HAVE BEEN UNDER 20 KT. NW TO N WIND
PATTERN RETURNS THIS AFTERNOON AND WILL BE THE DOMINANT FEATURE
OVER THE NEXT SEVERAL DAYS. LATEST MODELS IN GOOD AGREEMENT
SHOWING 20 TO 25 KT SUSTAINED SPEEDS DEVELOPING OVER THE OUTER
WATERS BY LATE THIS AFTERNOON AND CONTINUING THROUGH AT LEAST THU.
WILL KEEP SMALL CRAFT ADVISORY FOR WIND IN THE OUTER WATERS
BEGINNING 00Z WED. INNER WATERS WILL SEE 25 KT WIND GUSTS BEGIN A
LITTLE LATER. OUTER WATERS COULD SEE SMALL CRAFT ADVISORY WIND
GUSTS THROUGH THE WEEKEND.

SEAS HAVE NUDGED DOWN A BIT MORE...GENERALLY 5 TO 7 FT. LATEST
SPECTRAL GUIDANCE SUGGEST SEAS TO BECOME WIND WAVE DOMINATED
EARLY THIS EVENING AND CONTINUING FOR THE NEXT FEW DAYS. OUTER
WATERS LIKELY TO SEE WIND WAVES UP TO 6 FT...WITH A LONGER-PERIOD
SWELL COMPONENT OF 2-4 FT. SEAS WILL BECOME QUITE CHOPPY AND THERE
IS THE POTENTIAL FOR SQUARE SEAS STARTING WEDNESDAY. WILL KEEP AN
EYE ON LATEST MODEL GUIDANCE AND CONSIDER A SMALL CRAFT ADVISORY
FOR SEAS STARTING WEDNESDAY AFTERNOON. BOWEN/WEISHAAR

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS FROM 5 PM THIS AFTERNOON TO 7 PM
     PDT WEDNESDAY FOR WATERS FROM CAPE SHOALWATER WA TO
     FLORENCE OR FROM 10 TO 60 NM.

     SMALL CRAFT ADVISORY FOR WINDS FROM 11 PM THIS EVENING TO 7 PM
     PDT WEDNESDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA
     TO FLORENCE OR OUT 10 NM.
&&


$$

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

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





000
FXUS66 KPQR 031620
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
918 AM PDT TUE MAY  3 2016

.SYNOPSIS...SLOW MOVING COLD FRONT INCHING TOWARD THE COAST WILL
CONTINUE TO BRING THE THREAT OF SHOWERS TO THE REGION THROUGH
WEDNESDAY...WITH A STRAY THUNDERSTORM POSSIBLE EACH DAY IN THE
CASCADES. AS LOW-LEVEL FLOW TURNS INCREASINGLY ONSHORE...EXPECT
COOLER TEMPERATURES TO SPREAD INLAND TODAY AND WEDNESDAY. DRYING
TREND IS EXPECTED LATER IN THE WEEK AS THE REMNANTS OF THE FRONT
REORGANIZE INTO A CUTOFF LOW OVER CALIFORNIA. THIS WILL BRING A
RETURN TO OFFSHORE FLOW...WITH WARM AND DRY WEATHER THIS WEEKEND AS
HIGH PRESSURE BUILDS INTO THE PACIFIC NORTHWEST.

&&
.SHORT TERM...TODAY THROUGH THU...NO CHANGES. AFTER YET ANOTHER DAY
OF RECORD BREAKING WARMTH FOR SOME...TODAY SHOULD BE A BIT COOLER
ACROSS SW WA/NW OR AS LOW-LEVEL FLOW TURNS INCREASINGLY ONSHORE. PRES
GRADIENTS HAVE FLIPPED AROUND TO ONSHORE OVER THE PAST FEW HOURS...
BOTH ON THE SYNOPTIC AND MESO SCALES. KTTD-KDLS WAS AT ABOUT +3 MB AS
OF 2 AM...WITH KOTH-KGEG GRADIENTS TURNING ONSHORE AS WELL. THIS
WILL USHER IN A COOLER AIR MASS FROM THE PACIFIC AND HIGHS TODAY
SHOULD BE A GOOD 10-20 DEGREES COOLER THAN MONDAY FOR INLAND
AREAS...AROUND 70 IN THE VALLEYS. STRENGTHENING HIGH PRESSURE OVER
THE NE PACIFIC WILL KEEP ONSHORE FLOW GOING THROUGH AT LEAST
THURSDAY...BRINGING TEMPERATURES DOWN CLOSER TO NORMAL WED/THU.

SHOWERS CONTINUE TO DEVELOP IN THE SHALLOW/WEAK INSTABILITY BETWEEN
700-500 MB THIS MORNING...BUT DESPITE BEING ELEVATED CONVECTION THE
TOPS ARE STILL GENERALLY NOT HIGH/COLD ENOUGH TO CAUSE THE REQUISITE
CHARGE SEPARATION FOR LIGHTNING. DECIDED TO LEAVE THUNDER OUT OF THE
FORECAST THIS MORNING...THOUGH A STRAY STRIKE OR TWO LIKE THE ONES
RECENTLY OBSERVED OVER THE STRAIT OF JUAN DE FUCA ARE NOT OUT OF THE
QUESTION ANYWHERE. MODEL SOUNDINGS GENERALLY SHOW LITTLE CHANGE OVER
THE NEXT 48 HOURS...WITH LIMITED INSTABILITY AT BEST ABOVE 500 MB.
SURFACE-BASED CONVECTION WILL BRING MAINLY AFTERNOON/EVENING SHOWERS
THROUGH WEDNESDAY...BUT ALSO APPEARS TOO SHALLOW FOR LIGHTNING WEST
OF THE CASCADES EITHER DAY.

THE REMNANTS OF OUR DYING COLD FRONT/UPPER TROUGH ARE PROGGED TO
REORGANIZE INTO A CUTOFF UPPER LOW OVER CALIFORNIA BY THE END OF THE
WEEK...WHILE MOST MODELS BUILD AN UPPER RIDGE ACROSS SOUTHERN BC AND
WASHINGTON. THIS WILL GRADUALLY BRING A RETURN TO DRIER OFFSHORE FLOW
ALOFT BY THE WEEKEND...WITH THURSDAY APPEARING TO BE THE BEGINNING OF
THAT TRANSITION. SHOULD SEE SHOWERS DIMINISH AND BECOME INCREASINGLY
CONFINED TO THE CASCADES THU/FRI AS A RESULT.  WEAGLE

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...(THU NIGHT
THROUGH MON)... MODELS REMAIN IN FAIR
AGREEMENT THROUGH THE EXTENDED PERIOD AS THE UPPER LEVEL LOW
CONTINUES TO ADVANCE INTO THE GREAT BASIN WHILE AN UPPER RIDGE
BEGINS TO NOSE INTO THE PACIFIC NORTHWEST FROM THE NORTHEAST
PACIFIC. THIS WILL BRING AN END TO THE SHOWER CHANCES FOR MUCH OF
THE AREA ON FRIDAY...THOUGH WILL MAINTAIN A SLIGHT CHANCE FOR
SHOWERS OVER THE SOUTHERN PORTIONS OF THE CASCADE ZONES.
TEMPERATURES WILL WARM INTO THE WEEKEND BACK ABOVE SEASONAL NORMS
AS HEIGHTS RISE AND THE AIR MASS WARMS.   CULLEN

&&

.AVIATION...INLAND AREAS WILL CONTINUE WITH VFR BUT WITH PLENTY
OF MID-LEVEL CLOUDS IN SOUTH FLOW ALOFT. AFTERNOON HEATING WILL
LEAD TO A THREAT OF SHOWERS...PRIMARILY ALONG THE CASCADES.
COASTAL SITES WILL CONTINUE TO OSCILLATE BETWEEN VFR AND MVFR FOR
BOTH CIGS AND VIS. MODELS SUGGEST MUCH DEEPER MARINE CLOUD
PENETRATION INLAND AFTER 06Z WED.

KPDX AND APPROACHES...VFR CONDITIONS THROUGH AT LEAST 07Z WED.
PLENTY OF MID AND HIGH LEVEL CLOUDS THROUGH TUE EVENING WITH A
SLIM THREAT OF SHOWERS TUE AFTERNOON AND EVENING IN THE VICINITY.
MVFR CIGS COULD UP THE COLUMBIA RIVER TO NEAR KPDX AFTER 06Z TO AS
LATE AS TO 18Z WED. BOWEN/WEISHAAR
&&

.MARINE...SOUTH WIND REVERSAL ALONG THE COAST EARLY THIS
MORNING...BUT MAX GUSTS HAVE BEEN UNDER 20 KT. NW TO N WIND
PATTERN RETURNS THIS AFTERNOON AND WILL BE THE DOMINANT FEATURE
OVER THE NEXT SEVERAL DAYS. LATEST MODELS IN GOOD AGREEMENT
SHOWING 20 TO 25 KT SUSTAINED SPEEDS DEVELOPING OVER THE OUTER
WATERS BY LATE THIS AFTERNOON AND CONTINUING THROUGH AT LEAST THU.
WILL KEEP SMALL CRAFT ADVISORY FOR WIND IN THE OUTER WATERS
BEGINNING 00Z WED. INNER WATERS WILL SEE 25 KT WIND GUSTS BEGIN A
LITTLE LATER. OUTER WATERS COULD SEE SMALL CRAFT ADVISORY WIND
GUSTS THROUGH THE WEEKEND.

SEAS HAVE NUDGED DOWN A BIT MORE...GENERALLY 5 TO 7 FT. LATEST
SPECTRAL GUIDANCE SUGGEST SEAS TO BECOME WIND WAVE DOMINATED
EARLY THIS EVENING AND CONTINUING FOR THE NEXT FEW DAYS. OUTER
WATERS LIKELY TO SEE WIND WAVES UP TO 6 FT...WITH A LONGER-PERIOD
SWELL COMPONENT OF 2-4 FT. SEAS WILL BECOME QUITE CHOPPY AND THERE
IS THE POTENTIAL FOR SQUARE SEAS STARTING WEDNESDAY. WILL KEEP AN
EYE ON LATEST MODEL GUIDANCE AND CONSIDER A SMALL CRAFT ADVISORY
FOR SEAS STARTING WEDNESDAY AFTERNOON. BOWEN/WEISHAAR

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS FROM 5 PM THIS AFTERNOON TO 7 PM
     PDT WEDNESDAY FOR WATERS FROM CAPE SHOALWATER WA TO
     FLORENCE OR FROM 10 TO 60 NM.

     SMALL CRAFT ADVISORY FOR WINDS FROM 11 PM THIS EVENING TO 7 PM
     PDT WEDNESDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA
     TO FLORENCE OR OUT 10 NM.
&&


$$

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

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





000
FXUS66 KPQR 030943
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
243 AM PDT TUE MAY  3 2016

.SYNOPSIS...SLOW MOVING COLD FRONT INCHING TOWARD THE COAST WILL
CONTINUE TO BRING THE THREAT OF SHOWERS TO THE REGION THROUGH
WEDNESDAY...WITH A STRAY THUNDERSTORM POSSIBLE EACH DAY IN THE
CASCADES. AS LOW-LEVEL FLOW TURNS INCREASINGLY ONSHORE...EXPECT
COOLER TEMPERATURES TO SPREAD INLAND TODAY AND WEDNESDAY. DRYING
TREND IS EXPECTED LATER IN THE WEEK AS THE REMNANTS OF THE FRONT
REORGANIZE INTO A CUTOFF LOW OVER CALIFORNIA. THIS WILL BRING A
RETURN TO OFFSHORE FLOW...WITH WARM AND DRY WEATHER THIS WEEKEND AS
HIGH PRESSURE BUILDS INTO THE PACIFIC NORTHWEST.

&&

.SHORT TERM...TODAY THROUGH THURSDAY...AFTER YET ANOTHER DAY OF
RECORD BREAKING WARMTH FOR SOME...TODAY SHOULD BE A BIT COOLER ACROSS
SW WA/NW OR AS LOW-LEVEL FLOW TURNS INCREASINGLY ONSHORE. PRESSURE
GRADIENTS HAVE FLIPPED AROUND TO ONSHORE OVER THE PAST FEW HOURS...
BOTH ON THE SYNOPTIC AND MESO SCALES. KTTD-KDLS WAS AT ABOUT +3 MB AS
OF 2 AM...WITH KOTH-KGEG GRADIENTS TURNING ONSHORE AS WELL. THIS
WILL USHER IN A COOLER AIR MASS FROM THE PACIFIC AND HIGHS TODAY
SHOULD BE A GOOD 10-20 DEGREES COOLER THAN MONDAY FOR INLAND
AREAS...AROUND 70 IN THE VALLEYS. STRENGTHENING HIGH PRESSURE OVER
THE NE PACIFIC WILL KEEP ONSHORE FLOW GOING THROUGH AT LEAST
THURSDAY...BRINGING TEMPERATURES DOWN CLOSER TO NORMAL WED/THU.

SHOWERS CONTINUE TO DEVELOP IN THE SHALLOW/WEAK INSTABILITY BETWEEN
700-500 MB THIS MORNING...BUT DESPITE BEING ELEVATED CONVECTION THE
TOPS ARE STILL GENERALLY NOT HIGH/COLD ENOUGH TO CAUSE THE REQUISITE
CHARGE SEPARATION FOR LIGHTNING. DECIDED TO LEAVE THUNDER OUT OF THE
FORECAST THIS MORNING...THOUGH A STRAY STRIKE OR TWO LIKE THE ONES
RECENTLY OBSERVED OVER THE STRAIT OF JUAN DE FUCA ARE NOT OUT OF THE
QUESTION ANYWHERE. MODEL SOUNDINGS GENERALLY SHOW LITTLE CHANGE OVER
THE NEXT 48 HOURS...WITH LIMITED INSTABILITY AT BEST ABOVE 500 MB.
SURFACE-BASED CONVECTION WILL BRING MAINLY AFTERNOON/EVENING SHOWERS
THROUGH WEDNESDAY...BUT ALSO APPEARS TOO SHALLOW FOR LIGHTNING WEST
OF THE CASCADES EITHER DAY.

THE REMNANTS OF OUR DYING COLD FRONT/UPPER TROUGH ARE PROGGED TO
REORGANIZE INTO A CUTOFF UPPER LOW OVER CALIFORNIA BY THE END OF THE
WEEK...WHILE MOST MODELS BUILD AN UPPER RIDGE ACROSS SOUTHERN BC AND
WASHINGTON. THIS WILL GRADUALLY BRING A RETURN TO DRIER OFFSHORE FLOW
ALOFT BY THE WEEKEND...WITH THURSDAY APPEARING TO BE THE BEGINNING OF
THAT TRANSITION. SHOULD SEE SHOWERS DIMINISH AND BECOME INCREASINGLY
CONFINED TO THE CASCADES THU/FRI AS A RESULT.  WEAGLE

.LONG TERM...THURSDAY NIGHT THROUGH MONDAY.  MODELS REMAIN IN FAIR
AGREEMENT THROUGH THE EXTENDED PERIOD AS THE UPPER LEVEL LOW
CONTINUES TO ADVANCE INTO THE GREAT BASIN WHILE AN UPPER RIDGE
BEGINS TO NOSE INTO THE PACIFIC NORTHWEST FROM THE NORTHEAST
PACIFIC. THIS WILL BRING AN END TO THE SHOWER CHANCES FOR MUCH OF
THE AREA ON FRIDAY...THOUGH WILL MAINTAIN A SLIGHT CHANCE FOR
SHOWERS OVER THE SOUTHERN PORTIONS OF THE CASCADE ZONES.
TEMPERATURES WILL WARM INTO THE WEEKEND BACK ABOVE SEASONAL NORMS
AS HEIGHTS RISE AND THE AIR MASS WARMS.   CULLEN

&&

.AVIATION...MVFR ALONG THE COAST AT 10Z AS A SOUTH WIND REVERSAL
CONTINUES. LIKELY SEEING SOME OF THE MVFR CIGS PUSHING UP THE
MAJOR COASTAL RIVER DRAINAGES. VFR ELSEWHERE. COASTAL AREAS
EXPECTED TO REMAIN MVFR THROUGH AT LEAST EARLY AFTERNOON...THEN GO
TO A MIX OF MVFR TO LOW-END VFR. INLAND AREAS WILL CONTINUE WITH
VFR BUT WITH PLENTY OF MID-LEVEL CLOUDS IN SOUTH FLOW ALOFT.
AFTERNOON HEATING TUE WILL LEAD TO A THREAT OF SHOWERS...PRIMARILY
ALONG THE CASCADES. MODELS SUGGEST MUCH DEEPER MARINE CLOUD
PENETRATION INLAND AFTER 06Z WED.

KPDX AND APPROACHES...VFR CONDITIONS THROUGH AT LEAST 07Z WED.
PLENTY OF MID AND HIGH LEVEL CLOUDS THROUGH TUE EVENING WITH A
SLIM THREAT OF SHOWERS TUE AFTERNOON AND EVENING IN THE VICINITY.
MVFR CIGS COULD UP THE COLUMBIA RIVER TO NEAR KPDX 07Z TO 12Z WED.
WEISHAAR

&&

.MARINE...SOUTH WIND REVERSAL ALONG THE COAST EARLY THIS
MORNING...BUT MAX GUSTS HAVE BEEN UNDER 20 KT. NW TO N WIND
PATTERN RETURNS THIS AFTERNOON AND WILL BE THE DOMINANT FEATURE
OVER THE NEXT SEVERAL DAYS. LATEST MODELS IN GOOD AGREEMENT
SHOWING 20 TO 25 KT SUSTAINED SPEEDS DEVELOPING OVER THE OUTER
WATERS BY LATE THIS AFTERNOON AND CONTINUING THROUGH AT LEAST THU.
WILL GO WITH A SMALL CRAFT ADVISORY FOR WIND IN THE OUTER WATERS
BEGINNING 00Z WED. INNER WATERS WILL SEE 25 KT WIND GUSTS BEGIN A
LITTLE LATER. THUS...STARTED THE SMALL CRAFT ADVISORY THERE AT 06Z
WED. OUTER WATERS COULD SEE SMALL CRAFT ADVISORY WIND GUSTS
THROUGH THE WEEKEND.

SEAS HAVE NUDGED DOWN A BIT SINCE EARLIER THIS EVENING...GENERALLY
6 TO 7 FT. LATEST SPECTRAL GUIDANCE SUGGEST SEAS TO BECOME WIND-
WAVE DOMINATED EARLY TUE EVENING AND CONTINUE FOR THE NEXT FEW
DAYS. OUTER WATERS LIKELY TO SEE WIND WAVES UP TO 6 FT...WITH A
LONGER-PERIOD SWELL COMPONENT OF 2-4 FT. SEAS WILL BECOME QUITE
CHOPPY AND THERE IS THE POTENTIAL FOR SQUARE SEAS LATE THIS WEEK.
WEISHAAR

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS FROM 5 PM THIS AFTERNOON TO 7 PM
     PDT WEDNESDAY FOR WATERS FROM CAPE SHOALWATER WA TO
     FLORENCE OR FROM 10 TO 60 NM.

     SMALL CRAFT ADVISORY FOR WINDS FROM 11 PM THIS EVENING TO 7 PM
     PDT WEDNESDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA
     TO FLORENCE OR OUT 10 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 4 AM
     PDT EARLY THIS MORNING.

&&

$$

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 030316
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
815 PM PDT MON MAY  2 2016

.SYNOPSIS...SHOWERS AND MAYBE A FEW EVENING THUNDERSTORMS TONIGHT AND
AGAIN POSSIBLY ON TUE. OTHERWISE...WILL SEE RETURN TO INCREASED
ONSHORE FLOW AND THREAT OF SHOWERS FOR TUE AND WED. UNSETTLED WEATHER
CONTINUES THU AND FRI. THEN...LIKE PAST WEEKENDS...WARM AND DRY
CONDITIONS AS HIGH PRES BUILDS OVER THE REGION.
&&

.EVENING UPDATE...LOW CLOUDS APPEAR TO BE FILLING IN ALONG THE COAST
AS FORECASTED THIS EVENING. AS FAR AS THUNDERSTORMS...THE
THUNDERSTORMS THAT WERE TO OUR SOUTH IN DOUGLAS COUNTY APPEARED TO BE
VERY SHALLOW AND FELL APART AS THEY MOVE INTO LANE COUNTY. STILL
THINK THERE IS SOME THREAT FOR ISOLATED ELEVATED THUNDER...MAINLY IN
LANE COUNTY AND IN THE COAST RANGE...BUT ALSO A SLIGHT CHANCE A
SHOWER COULD PRODUCE A COUPLE STRIKES OF LIGHTNING IN THE CASCADES.
AM CHANGING THE ISOLATED THUNDER TO A SLIGHT CHANCE OF THUNDERSTORMS
IN THE CASCADES AND COAST RANGE. THE ELEVATED INSTABILITY IS THERE
AND WE ARE SEEING SHOWERS...BUT THERE MAY NOT BE ENOUGH TO GENERATE
MORE THAN ONE OR TWO WEAK THUNDERSTORMS THIS EVENING. -MCCOY

.PREVIOUS DISCUSSION FOLLOWS....SHORT TERM...(TONIGHT THROUGH THUR).
UPPER LOW PRES OFF THE CALIF COAST IS MAINTAINING S TO SE FLOW ACROSS
THE REGION TODAY THROUGH TUE. WEAK DISTURBANCES OVER NW CALIF WILL
LIFT N THIS EVENING. ALREADY HAVE QUITE A BIT OF SHOWERS AND ISOLATED
THUNDERSTORMS OVER NE CALIF INTO SOUTH CENTRAL OREGON. THIS ACTIVITY
WILL DRIFT N/NW THIS EVENING...WITH NEWER SHOWERS DEVELOPING OVER THE
OREGON CASCADES AND COAST RANGE. MODELS CONTINUE TO SHOW BEST THREAT
OF SHOWERS EXTENDING FROM CENTRAL CASCADES NORTHWESTWARD INTO THE
COAST RANGE LATER THIS EVENING. SUSPECT THIS WILL SEE SHOWERS DEVELOP
OVER THE CASCADES...THEN SEE SHOWERS POP OVER THE COAST RANGE LATER
THIS EVENING. OF INTEREST WILL BE THE THERMAL TROUGH...WHICH IS NOW
SLOWLY MOVING INLAND AWAY FROM THE COAST AND INTO THE COAST RANGE. AS
SUCH...THIS MAY ACT MUCH LIKE A COLD FRONT...AND ENHANCE THE LIFTING
AND RESULTANT SHOWERS OVER THE COAST RANGE THIS EVENING. STILL CAN
NOT ELIMINATE THE THUNDERSTORM THREAT FOR MOST AREAS AWAY THE
CASCADES...SO WILL MAINTAIN A SLIGHT CHANCE THIS EVENING.

OTHERWISE...RATHER PLEASANT EVENING FOR MOST AREAS. LOW CLOUDS NOW
STREAMING NORTHWARD ALONG THE S OREGON COAST. AT 2 PM...LEADING EDGE
WAS ABOUT 10 MILES OFFSHORE FROM FLORENCE. THESE LOW CLOUDS SHOULD
INCREASE ALONG THE COASTAL AREAS UP TO LINCOLN CITY THROUGH 8 PM...
WITH LOW CLOUDS SPREADING FARTHER NORTH LATER THIS EVENING. WHILE
ONSHORE GRADIENT IS NOT ALL THAT IMPRESSIVE OVERNIGHT INTO EARLY
TUE...SO WOULD EXPECT MARINE LAYER TO REMAIN SOMEWHAT SHALLOW...WITH
LITTLE IF ANY PUSH INLAND PAST THE COAST RANGE.

AS DAY PROGRESSES ON TUE...AND THE MAIN UPPER TROUGH THAT SITS
FARTHER OFFSHORE DRAWS CLOSER...THE ONSHORE FLOW WILL INCREASE. THIS
WILL ALLOW FOR INCREASING CLOUDS ON TUE. STILL DECENT SOUTHERLY FLOW
ALOFT...SO WILL KEEP CHANCE OF SHOWERS FOR THE REGION. BUT
INSTABILITY NOT LOOKING SO GOOD. STILL...WILL KEEP SOME MINOR THREAT
OF THUNDERSTORMS NEAR THE CASCADES CREST FOR THE AFTERNOON.

UPPER TROUGH WILL PUSH INTO THE PAC NW WED AND THU WED... WITH
MODERATE TO STRONG ONSHORE FLOW. WILL SEE MUCH COOLER CONDITIONS WITH
LOTS OF CLOUDS ACROSS THE REGION. WITH UPPER TROUGH OVER THE
REGION...BUT ANOTHER CUT OFF LOW LIKELY TO FORM OFF CALIF ON THU.
OVERALL...WED AND THU WILL BE RATHER CLOUDY WITH PLENTY OF SHOWERS
FOR THE REGION...ESPECIALLY OVER THE COAST RANGE AND THE CASCADES.
NOT MUCH THREAT OF THUNDER DUE TO LOT OF CLOUD COVER.WILL KEEP SLIGHT
CHANCE OF THUNDERSTORMS NEAR THE CASCADES CREST FOR WED
AFTERNOON/EVENING.ROCKEY.

.LONG TERM...THURSDAY NIGHT THROUGH MONDAY.  MODELS REMAIN IN FAIR
AGREEMENT THROUGH THE EXTENDED PERIOD AS THE UPPER LEVEL LOW
CONTINUES TO ADVANCE INTO THE GREAT BASIN WHILE AN UPPER RIDGE
BEGINS TO NOSE INTO THE PACIFIC NORTHWEST FROM THE NORTHEAST
PACIFIC. THIS WILL BRING AN END TO THE SHOWER CHANCES FOR MUCH OF
THE AREA ON FRIDAY...THOUGH WILL MAINTAIN A SLIGHT CHANCE FOR
SHOWERS OVER THE SOUTHERN PORTIONS OF THE CASCADE ZONES.
TEMPERATURES WILL WARM INTO THE WEEKEND BACK ABOVE SEASONAL NORMS
AS HEIGHTS RISE AND THE AIR MASS WARMS.   CULLEN
&&
.AVIATION...VFR CONDITIONS INLAND THROUGH TUESDAY WITH WINDS
SWITCHING ONSHORE. ALONG THE COAST...MARINE STRATUS CURRENTLY
MOVING NORTH FROM THE NORTHERN CALIFORNIA COAST WILL LIKELY ARRIVE
BETWEEN 01Z AND 08Z TUESDAY AND BRING A PERIOD OF IFR CONDITIONS
AND POSSIBLY BREEZY WINDS OUT OF THE SOUTH. THERE IS A SLIGHT
CHANCE OF THUNDERSTORMS THROUGH ABOUT 09Z TUE WITH THE BEST
CHANCES OVER THE MOUNTAINS BUT WITH A SMALL CHANCE ELSEWHERE.

KPDX AND APPROACHES...VFR CONDITIONS THROUGH TUESDAY AS TURNS
ONSHORE. ANY THUNDERSTORMS THAT DEVELOP WILL MOST LIKELY REMAIN
AWAY FROM KPDX.
&&

.MARINE...A SOUTHERLY WIND REVERSAL IS WORKING ITS WAY NORTH
ALONG THE COAST. MODELS HAVE BACK OFF WINDS WITH THE REVERSAL SO
DO NOT EXPECT SIGNIFICANT INCREASE IN WINDS OVER THE WATERS. A
WESTERLY SWELL HAS PUSHED SEAS TO AROUND 8 FT BUT SHOULD RELAX
TO 6 TO 7 FT TUESDAY.

HIGH PRESSURE BUILDING BACK INTO THE NORTHEAST PACIFIC SHOULD
BRING NORTHERLY WINDS BACK ON TUESDAY. STARTING TUESDAY
NIGHT...PERIODS OF GUSTY 25 TO 30 KT NORTHERLY WINDS ARE ON TAP
DURING...PARTICULARLY ACROSS THE CENTRAL OREGON WATERS. WHILE
SEAS SHOULD GENERALLY REMAIN UNDER 10 FT...EXPECT SEAS TO BECOME
ESPECIALLY STEEP AND HAZARDOUS DURING THE SECOND HALF OF THE WEEK
AS FRESH SWELL/WIND WAVE DOMINATE DUE TO PERIODS OF NORTH-
NORTHWESTERLY GALES OFF VANCOUVER ISLAND. BOWEN

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...NONE.
&&

$$

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 022145
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
245 PM PDT MON MAY  2 2016

.SYNOPSIS...SHOWERS AND MAYBE A FEW EVENING THUNDERSTORMS TODAY AND
AGAIN POSSIBLY ON TUE. OTHERWISE...WILL SEE RETURN TO INCREASED
ONSHORE FLOW AND THREAT OF SHOWERS FOR TUE AND WED. UNSETTLED WEATHER
CONTINUES THU AND FRI. THEN...LIKE PAST WEEKENDS...WARM AND DRY
CONDITIONS AS HIGH PRES BUILDS OVER THE REGION.
&&

.SHORT TERM...(TONIGHT THROUGH THUR). UPPER LOW PRES OFF THE CALIF
COAST IS MAINTAINING S TO SE FLOW ACROSS THE REGION TODAY THROUGH
TUE. WEAK DISTURBANCES OVER NW CALIF WILL LIFT N THIS EVENING.
ALREADY HAVE QUITE A BIT OF SHOWERS AND ISOLATED THUNDERSTORMS OVER
NE CALIF INTO SOUTH CENTRAL OREGON. THIS ACTIVITY WILL DRIFT N/NW
THIS EVENING...WITH NEWER SHOWERS DEVELOPING OVER THE OREGON CASCADES
AND COAST RANGE. MODELS CONTINUE TO SHOW BEST THREAT OF SHOWERS
EXTENDING FROM CENTRAL CASCADES NORTHWESTWARD INTO THE COAST RANGE
LATER THIS EVENING. SUSPECT THIS WILL SEE SHOWERS DEVELOP OVER THE
CASCADES...THEN SEE SHOWERS POP OVER THE COAST RANGE LATER THIS
EVENING. OF INTEREST WILL BE THE THERMAL TROUGH...WHICH IS NOW SLOWLY
MOVING INLAND AWAY FROM THE COAST AND INTO THE COAST RANGE. AS
SUCH...THIS MAY ACT MUCH LIKE A COLD FRONT...AND ENHANCE THE LIFTING
AND RESULTANT SHOWERS OVER THE COAST RANGE THIS EVENING. STILL CAN
NOT ELIMINATE THE THUNDERSTORM THREAT FOR MOST AREAS AWAY THE
CASCADES...SO WILL MAINTAIN A SLIGHT CHANCE THIS EVENING.

OTHERWISE...RATHER PLEASANT EVENING FOR MOST AREAS. LOW CLOUDS NOW
STREAMING NORTHWARD ALONG THE S OREGON COAST. AT 2 PM...LEADING EDGE
WAS ABOUT 10 MILES OFFSHORE FROM FLORENCE. THESE LOW CLOUDS SHOULD
INCREASE ALONG THE COASTAL AREAS UP TO LINCOLN CITY THROUGH 8 PM...
WITH LOW CLOUDS SPREADING FARTHER NORTH LATER THIS EVENING. WHILE
ONSHORE GRADIENT IS NOT ALL THAT IMPRESSIVE OVERNIGHT INTO EARLY
TUE...SO WOULD EXPECT MARINE LAYER TO REMAIN SOMEWHAT SHALLOW...WITH
LITTLE IF ANY PUSH INLAND PAST THE COAST RANGE.

AS DAY PROGRESSES ON TUE...AND THE MAIN UPPER TROUGH THAT SITS
FARTHER OFFSHORE DRAWS CLOSER...THE ONSHORE FLOW WILL INCREASE. THIS
WILL ALLOW FOR INCREASING CLOUDS ON TUE. STILL DECENT SOUTHERLY FLOW
ALOFT...SO WILL KEEP CHANCE OF SHOWERS FOR THE REGION. BUT
INSTABILITY NOT LOOKING SO GOOD. STILL...WILL KEEP SOME MINOR THREAT
OF THUNDERSTORMS NEAR THE CASCADES CREST FOR THE AFTERNOON.

UPPER TROUGH WILL PUSH INTO THE PAC NW WED AND THU WED... WITH
MODERATE TO STRONG ONSHORE FLOW. WILL SEE MUCH COOLER CONDITIONS WITH
LOTS OF CLOUDS ACROSS THE REGION. WITH UPPER TROUGH OVER THE
REGION...BUT ANOTHER CUT OFF LOW LIKELY TO FORM OFF CALIF ON THU.
OVERALL...WED AND THU WILL BE RATHER CLOUDY WITH PLENTY OF SHOWERS
FOR THE REGION...ESPECIALLY OVER THE COAST RANGE AND THE CASCADES.
NOT MUCH THREAT OF THUNDER DUE TO LOT OF CLOUD COVER.WILL KEEP SLIGHT
CHANCE OF THUNDERSTORMS NEAR THE CASCADES CREST FOR WED
AFTERNOON/EVENING.ROCKEY.

.LONG TERM...THURSDAY NIGHT THROUGH MONDAY.  MODELS REMAIN IN FAIR
AGREEMENT THROUGH THE EXTENDED PERIOD AS THE UPPER LEVEL LOW
CONTINUES TO ADVANCE INTO THE GREAT BASIN WHILE AN UPPER RIDGE
BEGINS TO NOSE INTO THE PACIFIC NORTHWEST FROM THE NORTHEAST
PACIFIC. THIS WILL BRING AN END TO THE SHOWER CHANCES FOR MUCH OF
THE AREA ON FRIDAY...THOUGH WILL MAINTAIN A SLIGHT CHANCE FOR
SHOWERS OVER THE SOUTHERN PORTIONS OF THE CASCADE ZONES.
TEMPERATURES WILL WARM INTO THE WEEKEND BACK ABOVE SEASONAL NORMS
AS HEIGHTS RISE AND THE AIR MASS WARMS.   CULLEN
&&
.AVIATION...VFR CONDITIONS INLAND THROUGH TUESDAY WITH WINDS
SWITCHING ONSHORE. ALONG THE COAST...MARINE STRATUS CURRENTLY
MOVING NORTH FROM THE NORTHERN CALIFORNIA COAST WILL LIKELY ARRIVE
BETWEEN 01Z AND 08Z TUESDAY AND BRING A PERIOD OF IFR CONDITIONS
AND POSSIBLY BREEZY WINDS OUT OF THE SOUTH. THERE IS A SLIGHT
CHANCE OF THUNDERSTORMS THROUGH ABOUT 09Z TUE WITH THE BEST
CHANCES OVER THE MOUNTAINS BUT WITH A SMALL CHANCE ELSEWHERE.

KPDX AND APPROACHES...VFR CONDITIONS THROUGH TUESDAY AS TURNS
ONSHORE. ANY THUNDERSTORMS THAT DEVELOP WILL MOST LIKELY REMAIN
AWAY FROM KPDX.
&&

.MARINE...A SOUTHERLY WIND REVERSAL IS WORKING ITS WAY NORTH
ALONG THE COAST. MODELS HAVE BACK OFF WINDS WITH THE REVERSAL SO
DO NOT EXPECT SIGNIFICANT INCREASE IN WINDS OVER THE WATERS. A
WESTERLY SWELL HAS PUSHED SEAS TO AROUND 8 FT BUT SHOULD RELAX
TO 6 TO 7 FT TUESDAY.

HIGH PRESSURE BUILDING BACK INTO THE NORTHEAST PACIFIC SHOULD
BRING NORTHERLY WINDS BACK ON TUESDAY. STARTING TUESDAY
NIGHT...PERIODS OF GUSTY 25 TO 30 KT NORTHERLY WINDS ARE ON TAP
DURING...PARTICULARLY ACROSS THE CENTRAL OREGON WATERS. WHILE
SEAS SHOULD GENERALLY REMAIN UNDER 10 FT...EXPECT SEAS TO BECOME
ESPECIALLY STEEP AND HAZARDOUS DURING THE SECOND HALF OF THE WEEK
AS FRESH SWELL/WIND WAVE DOMINATE DUE TO PERIODS OF NORTH-
NORTHWESTERLY GALES OFF VANCOUVER ISLAND. BOWEN

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...NONE.
&&

$$

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 021540
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
845 AM PDT MON MAY  2 2016

.SYNOPSIS...ANOTHER WARM DAY IS ON TAP TODAY AS AN UPPER LEVEL RIDGE
REMAINS DOMINANT OVER WESTERN CANADA AND THE PAC NW. CHANGES WILL
BEGIN LATER TODAY AS A SLOW MOVING COLD FRONT INCHES TOWARD THE
COAST. THIS WILL TURN THE FLOW ALOFT MORE SOUTHERLY...BRINGING
MOISTURE AND INSTABILITY NORTHWARD FROM THE SIERRA NEVADA. THE RESULT
WILL BE INCREASING SHOWERS AND A CHANCE FOR THUNDER LATE THIS
AFTERNOON INTO TONIGHT. LOW-LEVEL FLOW WILL TURN ONSHORE...FIRST
COOLING OFF THE COAST TODAY...THEN INLAND AREAS TUESDAY. THE REMNANTS
OF THE FRONT AND ASSOCIATED UPPER TROUGH KEEP SHOWERS IN THE FORECAST
THROUGH THURSDAY...THEN FLOW TURNS OFFSHORE AGAIN FOR ANOTHER WARMING
AND DRYING TREND BY THE WEEKEND.

&&

.SHORT TERM...TODAY THROUGH WEDNESDAY...NO CHANGE TO GRIDS/TRENDS.
THIS MORNING IS STARTING OFF QUITE WARM FOR MOST OF THE FORECAST
AREA...WITH TEMPERATURES STILL IN THE MID 50S TO MID 60S FOR ALL BUT
THE MOST SHELTERED VALLEY LOCATIONS. 850 MB TEMPS LOOK TO BE 1-2 DEG
C WARMER THAN SUNDAY...MEANWHILE GENERAL OFFSHORE FLOW CONTINUES THIS
MORNING AS THERMAL LOW PRESSURE LINGERS JUST OFF THE COAST. THIS
SHOULD ALLOW TEMPS TO EASILY CLIMB BACK INTO THE 80S TODAY FOR MOST
INLAND VALLEYS...POSSIBLY BREAKING A COUPLE RECORDS.

DECIDED TO BUMP UP FCST HIGHS A BIT ALONG THE COAST AS IT MAY TAKE A
FEW HOURS AFTER SUNRISE FOR THE SEABREEZE TO KICK IN. THE BULK OF THE
ANTICIPATED SOUTHERLY WIND REVERSAL IS JUST NOW APPROACHING CAPE
MENDOCINO IN NORTHERN CALIFORNIA...SO THAT WILL PROBABLY TAKE A FEW
HOURS TO ARRIVE ALONG THE CENTRAL OR COAST AS WELL. ON THE OTHER
HAND...THE SYNOPTIC-SCALE FORCING FOR OFFSHORE FLOW IS WANING AS
SPOKANE-NORTH BEND PRESSURE GRADIENTS ARE DOWN TO 4.3 MB AS OF 2 AM.
ALL THIS SHOULD ALLOW THERMAL LOW PRESSURE TO MIGRATE ONSHORE TODAY
BUT AFTER A SLIGHT DELAY...WITH ONSHORE FLOW RETURNING TO THE
IMMEDIATE COAST AND COASTAL VALLEYS BY EARLY AFTERNOON. AS A RESULT
HIGHS ALONG THE COAST TODAY SHOULD BE ABOUT 10 DEGREES COOLER THAN
YESTERDAY.

THE THERMAL TROUGH WILL TAKE SOME TIME TO CROSS THE COAST RANGE...
BUT SHOULD DO SO BY LATE AFTERNOON. THIS WILL BRING A PUSH OF MARINE
AIR FURTHER INLAND THIS EVENING...THE LEADING EDGE OF WHICH MAY SERVE
AS A TRIGGER FOR SURFACE-BASED CONVECTION DEPENDING ON WHICH MODEL
ONE BELIEVES. LATEST RUNS OF THE GFS...NAM...AND ECMWF DO SUGGEST
ABOUT 500-1000 J/KG OF SFC-BASED CAPE THIS AFTERNOON. MODELS HAVE
VARYING DEGREES OF CONVECTIVE INHIBITION...WITH THE 00Z GFS SHOWING
LITTLE WHILE THE NAM SHOWS AROUND 100 J/KG OF CIN FOR THE WILLAMETTE
VALLEY. MOST CONVECTIVE-ALLOWING MODELS SUGGEST CELLS WILL DEVELOP IN
THE LANE/DOUGLAS CASCADES SOMETIME AFTER 3 PM THIS AFTERNOON...WITH
SOME MODELS SHOWING ADDITIONAL CONVECTION DEVELOPING ON THE COAST
RANGE WITH THE LEADING EDGE OF THE MARINE PUSH. MODEL SOUNDINGS
SUGGEST FAIRLY HIGH BASES INITIALLY...WITH AS MUCH AS 1000 J/KG OF
DCAPE BUT FAIRLY WEAK SHEAR. THIS COULD CAUSE SOME OF THE STRONGER
CELLS TO PRODUCE STRONGER-THAN-USUAL OUTFLOW... PERHAPS GUSTS UP TO
30-40 MPH FROM SOME OF THE STRONGER CELLS. STEERING FLOW IS FROM THE
S-SE...WHICH COULD CAUSE SOME OF THE CELLS DEVELOPING IN THE CASCADES
TO DRIFT OVER THE WILLAMETTE VALLEY THIS EVENING. A SLOWLY
APPROACHING COLD FRONT MAY ALSO PROVIDE SOME ELEVATED INSTABILITY
OVERNIGHT...WHICH WOULD BRING A SLIGHT CHANCE OF THUNDER TO JUST
ABOUT ANYONE IN THE FORECAST AREA. HOWEVER LATEST MODEL RUNS HAVE
SEEMED TO BACK OFF ON THIS A BIT.

06Z NAM BOUNDARY LAYER RH INCREASES RAPIDLY ALONG THE COAST
TONIGHT...SUGGESTING FOG AND LOW CLOUDS WILL EVENTUALLY DEVELOP
BEHIND THE SOUTHERLY WIND REVERSAL. PRESSURE GRADIENTS TURN
INCREASINGLY ONSHORE TUESDAY AS THERMAL LOW PRESSURE SHIFTS EAST OF
THE CASCADES AND HIGHER PRESSURE BUILDS IN OFFSHORE. THIS SHOULD
BRING A 10-15 DEGREE COOL DOWN TO INLAND AREAS TUESDAY THEN ANOTHER
5-10 DEGREES FOR HIGHS IN THE LOWER TO MID 60S WED. THE REMNANTS OF
THE INCOMING COLD FRONT SHOULD PROVIDE ENOUGH MOISTURE FOR PLENTY OF
SHOWERS TUE/WED...ESPECIALLY IN THE HIGHER TERRAIN. THE STABILIZING
INFLUENCE OF ONSHORE FLOW AND THE MARINE LAYER WILL PROBABLY LIMIT
THUNDER TO NEAR THE CASCADE CREST AND AREAS EASTWARD TUESDAY AND
WEDNESDAY.  WEAGLE

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
WEDNESDAY NIGHT THROUGH SUNDAY. UPPER LEVEL TROUGH OVER THE EASTERN
PACIFIC JUST OFF THE NORTHERN CALIFORNIA COAST WILL REMAIN IN PLACE
THROUGH MUCH OF THE SECOND HALF OF THE WEEK BEFORE SLOWLY ADVANCING
INLAND INTO THE GREAT BASIN AND CUTTING OFF AS AN UPPER RIDGE NOSES
INTO THE PACIFIC NORTHWEST. SHOWERS SHOULD CONTINUE ACROSS THE AREA
ON THURSDAY...BUT TAPER OFF FOR MOST LOCATIONS ON FRIDAY AS THE
RIDGING BUILDS OVER THE REGION AND THE UPPER LOW MOVES FURTHER INTO
THE SOUTHWEST U.S. DID MAINTAIN SLIGHT CHANCE OF SHOWERS OVER THE
CASCADES HOWEVER...GIVEN BOTH THE POTENTIAL FOR SHOWERS TO WRAP
AROUND THE LOW AND SOME UNCERTAINTY IN THE EVOLUTION OF HOW FAR SOUTH
THE UPPER LOW MOVES. DAYTIME TEMPERATURES THURSDAY WILL BE CLOSER TO
SEASONAL NORMS...BEFORE WARMING INTO THE 70S INLAND AS HEIGHTS RISE
IN THE WARMING AIR MASS.  CULLEN

&&
.AVIATION...EXPECT PRIMARILY VFR CONDITIONS AT ALL INLAND TAF SITES
THROUGH TONIGHT AS OFFSHORE FLOW GIVES WAY TO INCREASING ONSHORE
FLOW LATE MONDAY. ALONG THE COAST...MARINE STRATUS CURRENTLY MOVING
NORTH FROM THE NORTHERN CALIFORNIA COAST WILL LIKELY ARRIVE BETWEEN
00Z AND 06Z TUESDAY AND BRING A PERIOD OF IFR CONDITIONS. THERE IS A
SLIGHT CHANCE OF THUNDERSTORMS FROM ABOUT 21Z MON THRU 09Z TUE WITH
THE BEST CHANCES OVER THE MOUNTAINS. HOWEVER THERE IS A SMALL CHANCE
ELSEWHERE.

KPDX AND APPROACHES...VFR CONDITIONS THROUGH TONIGHT AS OFFSHORE
FLOW DECREASES OVER THE REGION. ANY THUNDERSTORMS THAT DEVELOP
WILL MOST LIKELY REMAIN AWAY FROM KPDX.

&&

.MARINE...A SOUTHERLY WIND REVERSAL IS WORKING ITS WAY NORTH
ALONG THE COAST. MODELS CONTINUE TO SHOW A PERIOD OF GUSTY 20 KT
SOUTH WINDS THIS MORNING PRIMARILY BETWEEN 10 AND 30 MILES
OFFSHORE. A WESTERLY SWELL SHOULD PUSH SEAS TEMPORARILY INTO THE 7
TO 8 FT RANGE TODAY...BUT SEAS LOOK TO RELAX TUESDAY.

HIGH PRESSURE BUILDING BACK INTO THE NORTHEAST PACIFIC SHOULD
BRING NORTHERLY WINDS BACK ON TUESDAY. PERIODS OF GUSTY 25 TO 30
KT NORTHERLY WINDS ARE ON TAP DURING THE SECOND HALF OF THE WEEK
AND POSSIBLY NEXT WEEKEND AS WELL...PARTICULARLY ACROSS THE
CENTRAL OREGON WATERS. WHILE SEAS SHOULD GENERALLY REMAIN UNDER 10
FT...EXPECT SEAS TO BECOME ESPECIALLY STEEP AND HAZARDOUS DURING
THE SECOND HALF OF THE WEEK AS FRESH SWELL/WIND WAVE DOMINATE DUE
TO PERIODS OF NORTH-NORTHWESTERLY GALES OFF VANCOUVER ISLAND.
BOWEN/MH

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...NONE.

&&

$$

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 021540
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
845 AM PDT MON MAY  2 2016

.SYNOPSIS...ANOTHER WARM DAY IS ON TAP TODAY AS AN UPPER LEVEL RIDGE
REMAINS DOMINANT OVER WESTERN CANADA AND THE PAC NW. CHANGES WILL
BEGIN LATER TODAY AS A SLOW MOVING COLD FRONT INCHES TOWARD THE
COAST. THIS WILL TURN THE FLOW ALOFT MORE SOUTHERLY...BRINGING
MOISTURE AND INSTABILITY NORTHWARD FROM THE SIERRA NEVADA. THE RESULT
WILL BE INCREASING SHOWERS AND A CHANCE FOR THUNDER LATE THIS
AFTERNOON INTO TONIGHT. LOW-LEVEL FLOW WILL TURN ONSHORE...FIRST
COOLING OFF THE COAST TODAY...THEN INLAND AREAS TUESDAY. THE REMNANTS
OF THE FRONT AND ASSOCIATED UPPER TROUGH KEEP SHOWERS IN THE FORECAST
THROUGH THURSDAY...THEN FLOW TURNS OFFSHORE AGAIN FOR ANOTHER WARMING
AND DRYING TREND BY THE WEEKEND.

&&

.SHORT TERM...TODAY THROUGH WEDNESDAY...NO CHANGE TO GRIDS/TRENDS.
THIS MORNING IS STARTING OFF QUITE WARM FOR MOST OF THE FORECAST
AREA...WITH TEMPERATURES STILL IN THE MID 50S TO MID 60S FOR ALL BUT
THE MOST SHELTERED VALLEY LOCATIONS. 850 MB TEMPS LOOK TO BE 1-2 DEG
C WARMER THAN SUNDAY...MEANWHILE GENERAL OFFSHORE FLOW CONTINUES THIS
MORNING AS THERMAL LOW PRESSURE LINGERS JUST OFF THE COAST. THIS
SHOULD ALLOW TEMPS TO EASILY CLIMB BACK INTO THE 80S TODAY FOR MOST
INLAND VALLEYS...POSSIBLY BREAKING A COUPLE RECORDS.

DECIDED TO BUMP UP FCST HIGHS A BIT ALONG THE COAST AS IT MAY TAKE A
FEW HOURS AFTER SUNRISE FOR THE SEABREEZE TO KICK IN. THE BULK OF THE
ANTICIPATED SOUTHERLY WIND REVERSAL IS JUST NOW APPROACHING CAPE
MENDOCINO IN NORTHERN CALIFORNIA...SO THAT WILL PROBABLY TAKE A FEW
HOURS TO ARRIVE ALONG THE CENTRAL OR COAST AS WELL. ON THE OTHER
HAND...THE SYNOPTIC-SCALE FORCING FOR OFFSHORE FLOW IS WANING AS
SPOKANE-NORTH BEND PRESSURE GRADIENTS ARE DOWN TO 4.3 MB AS OF 2 AM.
ALL THIS SHOULD ALLOW THERMAL LOW PRESSURE TO MIGRATE ONSHORE TODAY
BUT AFTER A SLIGHT DELAY...WITH ONSHORE FLOW RETURNING TO THE
IMMEDIATE COAST AND COASTAL VALLEYS BY EARLY AFTERNOON. AS A RESULT
HIGHS ALONG THE COAST TODAY SHOULD BE ABOUT 10 DEGREES COOLER THAN
YESTERDAY.

THE THERMAL TROUGH WILL TAKE SOME TIME TO CROSS THE COAST RANGE...
BUT SHOULD DO SO BY LATE AFTERNOON. THIS WILL BRING A PUSH OF MARINE
AIR FURTHER INLAND THIS EVENING...THE LEADING EDGE OF WHICH MAY SERVE
AS A TRIGGER FOR SURFACE-BASED CONVECTION DEPENDING ON WHICH MODEL
ONE BELIEVES. LATEST RUNS OF THE GFS...NAM...AND ECMWF DO SUGGEST
ABOUT 500-1000 J/KG OF SFC-BASED CAPE THIS AFTERNOON. MODELS HAVE
VARYING DEGREES OF CONVECTIVE INHIBITION...WITH THE 00Z GFS SHOWING
LITTLE WHILE THE NAM SHOWS AROUND 100 J/KG OF CIN FOR THE WILLAMETTE
VALLEY. MOST CONVECTIVE-ALLOWING MODELS SUGGEST CELLS WILL DEVELOP IN
THE LANE/DOUGLAS CASCADES SOMETIME AFTER 3 PM THIS AFTERNOON...WITH
SOME MODELS SHOWING ADDITIONAL CONVECTION DEVELOPING ON THE COAST
RANGE WITH THE LEADING EDGE OF THE MARINE PUSH. MODEL SOUNDINGS
SUGGEST FAIRLY HIGH BASES INITIALLY...WITH AS MUCH AS 1000 J/KG OF
DCAPE BUT FAIRLY WEAK SHEAR. THIS COULD CAUSE SOME OF THE STRONGER
CELLS TO PRODUCE STRONGER-THAN-USUAL OUTFLOW... PERHAPS GUSTS UP TO
30-40 MPH FROM SOME OF THE STRONGER CELLS. STEERING FLOW IS FROM THE
S-SE...WHICH COULD CAUSE SOME OF THE CELLS DEVELOPING IN THE CASCADES
TO DRIFT OVER THE WILLAMETTE VALLEY THIS EVENING. A SLOWLY
APPROACHING COLD FRONT MAY ALSO PROVIDE SOME ELEVATED INSTABILITY
OVERNIGHT...WHICH WOULD BRING A SLIGHT CHANCE OF THUNDER TO JUST
ABOUT ANYONE IN THE FORECAST AREA. HOWEVER LATEST MODEL RUNS HAVE
SEEMED TO BACK OFF ON THIS A BIT.

06Z NAM BOUNDARY LAYER RH INCREASES RAPIDLY ALONG THE COAST
TONIGHT...SUGGESTING FOG AND LOW CLOUDS WILL EVENTUALLY DEVELOP
BEHIND THE SOUTHERLY WIND REVERSAL. PRESSURE GRADIENTS TURN
INCREASINGLY ONSHORE TUESDAY AS THERMAL LOW PRESSURE SHIFTS EAST OF
THE CASCADES AND HIGHER PRESSURE BUILDS IN OFFSHORE. THIS SHOULD
BRING A 10-15 DEGREE COOL DOWN TO INLAND AREAS TUESDAY THEN ANOTHER
5-10 DEGREES FOR HIGHS IN THE LOWER TO MID 60S WED. THE REMNANTS OF
THE INCOMING COLD FRONT SHOULD PROVIDE ENOUGH MOISTURE FOR PLENTY OF
SHOWERS TUE/WED...ESPECIALLY IN THE HIGHER TERRAIN. THE STABILIZING
INFLUENCE OF ONSHORE FLOW AND THE MARINE LAYER WILL PROBABLY LIMIT
THUNDER TO NEAR THE CASCADE CREST AND AREAS EASTWARD TUESDAY AND
WEDNESDAY.  WEAGLE

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
WEDNESDAY NIGHT THROUGH SUNDAY. UPPER LEVEL TROUGH OVER THE EASTERN
PACIFIC JUST OFF THE NORTHERN CALIFORNIA COAST WILL REMAIN IN PLACE
THROUGH MUCH OF THE SECOND HALF OF THE WEEK BEFORE SLOWLY ADVANCING
INLAND INTO THE GREAT BASIN AND CUTTING OFF AS AN UPPER RIDGE NOSES
INTO THE PACIFIC NORTHWEST. SHOWERS SHOULD CONTINUE ACROSS THE AREA
ON THURSDAY...BUT TAPER OFF FOR MOST LOCATIONS ON FRIDAY AS THE
RIDGING BUILDS OVER THE REGION AND THE UPPER LOW MOVES FURTHER INTO
THE SOUTHWEST U.S. DID MAINTAIN SLIGHT CHANCE OF SHOWERS OVER THE
CASCADES HOWEVER...GIVEN BOTH THE POTENTIAL FOR SHOWERS TO WRAP
AROUND THE LOW AND SOME UNCERTAINTY IN THE EVOLUTION OF HOW FAR SOUTH
THE UPPER LOW MOVES. DAYTIME TEMPERATURES THURSDAY WILL BE CLOSER TO
SEASONAL NORMS...BEFORE WARMING INTO THE 70S INLAND AS HEIGHTS RISE
IN THE WARMING AIR MASS.  CULLEN

&&
.AVIATION...EXPECT PRIMARILY VFR CONDITIONS AT ALL INLAND TAF SITES
THROUGH TONIGHT AS OFFSHORE FLOW GIVES WAY TO INCREASING ONSHORE
FLOW LATE MONDAY. ALONG THE COAST...MARINE STRATUS CURRENTLY MOVING
NORTH FROM THE NORTHERN CALIFORNIA COAST WILL LIKELY ARRIVE BETWEEN
00Z AND 06Z TUESDAY AND BRING A PERIOD OF IFR CONDITIONS. THERE IS A
SLIGHT CHANCE OF THUNDERSTORMS FROM ABOUT 21Z MON THRU 09Z TUE WITH
THE BEST CHANCES OVER THE MOUNTAINS. HOWEVER THERE IS A SMALL CHANCE
ELSEWHERE.

KPDX AND APPROACHES...VFR CONDITIONS THROUGH TONIGHT AS OFFSHORE
FLOW DECREASES OVER THE REGION. ANY THUNDERSTORMS THAT DEVELOP
WILL MOST LIKELY REMAIN AWAY FROM KPDX.

&&

.MARINE...A SOUTHERLY WIND REVERSAL IS WORKING ITS WAY NORTH
ALONG THE COAST. MODELS CONTINUE TO SHOW A PERIOD OF GUSTY 20 KT
SOUTH WINDS THIS MORNING PRIMARILY BETWEEN 10 AND 30 MILES
OFFSHORE. A WESTERLY SWELL SHOULD PUSH SEAS TEMPORARILY INTO THE 7
TO 8 FT RANGE TODAY...BUT SEAS LOOK TO RELAX TUESDAY.

HIGH PRESSURE BUILDING BACK INTO THE NORTHEAST PACIFIC SHOULD
BRING NORTHERLY WINDS BACK ON TUESDAY. PERIODS OF GUSTY 25 TO 30
KT NORTHERLY WINDS ARE ON TAP DURING THE SECOND HALF OF THE WEEK
AND POSSIBLY NEXT WEEKEND AS WELL...PARTICULARLY ACROSS THE
CENTRAL OREGON WATERS. WHILE SEAS SHOULD GENERALLY REMAIN UNDER 10
FT...EXPECT SEAS TO BECOME ESPECIALLY STEEP AND HAZARDOUS DURING
THE SECOND HALF OF THE WEEK AS FRESH SWELL/WIND WAVE DOMINATE DUE
TO PERIODS OF NORTH-NORTHWESTERLY GALES OFF VANCOUVER ISLAND.
BOWEN/MH

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...NONE.

&&

$$

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 021456
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
752 AM PDT MON MAY  2 2016

.SYNOPSIS...ANOTHER WARM DAY IS ON TAP TODAY AS AN UPPER LEVEL RIDGE
REMAINS DOMINANT OVER WESTERN CANADA AND THE PAC NW. CHANGES WILL
BEGIN LATER TODAY AS A SLOW MOVING COLD FRONT INCHES TOWARD THE
COAST. THIS WILL TURN THE FLOW ALOFT MORE SOUTHERLY...BRINGING
MOISTURE AND INSTABILITY NORTHWARD FROM THE SIERRA NEVADA. THE RESULT
WILL BE INCREASING SHOWERS AND A CHANCE FOR THUNDER LATE THIS
AFTERNOON INTO TONIGHT. LOW-LEVEL FLOW WILL TURN ONSHORE...FIRST
COOLING OFF THE COAST TODAY...THEN INLAND AREAS TUESDAY. THE REMNANTS
OF THE FRONT AND ASSOCIATED UPPER TROUGH KEEP SHOWERS IN THE FORECAST
THROUGH THURSDAY...THEN FLOW TURNS OFFSHORE AGAIN FOR ANOTHER WARMING
AND DRYING TREND BY THE WEEKEND.

&&

.SHORT TERM...TODAY THROUGH WEDNESDAY...NO CHANGE TO GRIDS/TRENDS.
THIS MORNING IS STARTING OFF QUITE WARM FOR MOST OF THE FORECAST
AREA...WITH TEMPERATURES STILL IN THE MID 50S TO MID 60S FOR ALL BUT
THE MOST SHELTERED VALLEY LOCATIONS. 850 MB TEMPS LOOK TO BE 1-2 DEG
C WARMER THAN SUNDAY...MEANWHILE GENERAL OFFSHORE FLOW CONTINUES THIS
MORNING AS THERMAL LOW PRESSURE LINGERS JUST OFF THE COAST. THIS
SHOULD ALLOW TEMPS TO EASILY CLIMB BACK INTO THE 80S TODAY FOR MOST
INLAND VALLEYS...POSSIBLY BREAKING A COUPLE RECORDS.

DECIDED TO BUMP UP FCST HIGHS A BIT ALONG THE COAST AS IT MAY TAKE A
FEW HOURS AFTER SUNRISE FOR THE SEABREEZE TO KICK IN. THE BULK OF THE
ANTICIPATED SOUTHERLY WIND REVERSAL IS JUST NOW APPROACHING CAPE
MENDOCINO IN NORTHERN CALIFORNIA...SO THAT WILL PROBABLY TAKE A FEW
HOURS TO ARRIVE ALONG THE CENTRAL OR COAST AS WELL. ON THE OTHER
HAND...THE SYNOPTIC-SCALE FORCING FOR OFFSHORE FLOW IS WANING AS
SPOKANE-NORTH BEND PRESSURE GRADIENTS ARE DOWN TO 4.3 MB AS OF 2 AM.
ALL THIS SHOULD ALLOW THERMAL LOW PRESSURE TO MIGRATE ONSHORE TODAY
BUT AFTER A SLIGHT DELAY...WITH ONSHORE FLOW RETURNING TO THE
IMMEDIATE COAST AND COASTAL VALLEYS BY EARLY AFTERNOON. AS A RESULT
HIGHS ALONG THE COAST TODAY SHOULD BE ABOUT 10 DEGREES COOLER THAN
YESTERDAY.

THE THERMAL TROUGH WILL TAKE SOME TIME TO CROSS THE COAST RANGE...
BUT SHOULD DO SO BY LATE AFTERNOON. THIS WILL BRING A PUSH OF MARINE
AIR FURTHER INLAND THIS EVENING...THE LEADING EDGE OF WHICH MAY SERVE
AS A TRIGGER FOR SURFACE-BASED CONVECTION DEPENDING ON WHICH MODEL
ONE BELIEVES. LATEST RUNS OF THE GFS...NAM...AND ECMWF DO SUGGEST
ABOUT 500-1000 J/KG OF SFC-BASED CAPE THIS AFTERNOON. MODELS HAVE
VARYING DEGREES OF CONVECTIVE INHIBITION...WITH THE 00Z GFS SHOWING
LITTLE WHILE THE NAM SHOWS AROUND 100 J/KG OF CIN FOR THE WILLAMETTE
VALLEY. MOST CONVECTIVE-ALLOWING MODELS SUGGEST CELLS WILL DEVELOP IN
THE LANE/DOUGLAS CASCADES SOMETIME AFTER 3 PM THIS AFTERNOON...WITH
SOME MODELS SHOWING ADDITIONAL CONVECTION DEVELOPING ON THE COAST
RANGE WITH THE LEADING EDGE OF THE MARINE PUSH. MODEL SOUNDINGS
SUGGEST FAIRLY HIGH BASES INITIALLY...WITH AS MUCH AS 1000 J/KG OF
DCAPE BUT FAIRLY WEAK SHEAR. THIS COULD CAUSE SOME OF THE STRONGER
CELLS TO PRODUCE STRONGER-THAN-USUAL OUTFLOW... PERHAPS GUSTS UP TO
30-40 MPH FROM SOME OF THE STRONGER CELLS. STEERING FLOW IS FROM THE
S-SE...WHICH COULD CAUSE SOME OF THE CELLS DEVELOPING IN THE CASCADES
TO DRIFT OVER THE WILLAMETTE VALLEY THIS EVENING. A SLOWLY
APPROACHING COLD FRONT MAY ALSO PROVIDE SOME ELEVATED INSTABILITY
OVERNIGHT...WHICH WOULD BRING A SLIGHT CHANCE OF THUNDER TO JUST
ABOUT ANYONE IN THE FORECAST AREA. HOWEVER LATEST MODEL RUNS HAVE
SEEMED TO BACK OFF ON THIS A BIT.

06Z NAM BOUNDARY LAYER RH INCREASES RAPIDLY ALONG THE COAST
TONIGHT...SUGGESTING FOG AND LOW CLOUDS WILL EVENTUALLY DEVELOP
BEHIND THE SOUTHERLY WIND REVERSAL. PRESSURE GRADIENTS TURN
INCREASINGLY ONSHORE TUESDAY AS THERMAL LOW PRESSURE SHIFTS EAST OF
THE CASCADES AND HIGHER PRESSURE BUILDS IN OFFSHORE. THIS SHOULD
BRING A 10-15 DEGREE COOL DOWN TO INLAND AREAS TUESDAY THEN ANOTHER
5-10 DEGREES FOR HIGHS IN THE LOWER TO MID 60S WED. THE REMNANTS OF
THE INCOMING COLD FRONT SHOULD PROVIDE ENOUGH MOISTURE FOR PLENTY OF
SHOWERS TUE/WED...ESPECIALLY IN THE HIGHER TERRAIN. THE STABILIZING
INFLUENCE OF ONSHORE FLOW AND THE MARINE LAYER WILL PROBABLY LIMIT
THUNDER TO NEAR THE CASCADE CREST AND AREAS EASTWARD TUESDAY AND
WEDNESDAY.  WEAGLE

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
WEDNESDAY NIGHT THROUGH SUNDAY. UPPER LEVEL TROUGH OVER THE EASTERN
PACIFIC JUST OFF THE NORTHERN CALIFORNIA COAST WILL REMAIN IN PLACE
THROUGH MUCH OF THE SECOND HALF OF THE WEEK BEFORE SLOWLY ADVANCING
INLAND INTO THE GREAT BASIN AND CUTTING OFF AS AN UPPER RIDGE NOSES
INTO THE PACIFIC NORTHWEST. SHOWERS SHOULD CONTINUE ACROSS THE AREA
ON THURSDAY...BUT TAPER OFF FOR MOST LOCATIONS ON FRIDAY AS THE
RIDGING BUILDS OVER THE REGION AND THE UPPER LOW MOVES FURTHER INTO
THE SOUTHWEST U.S. DID MAINTAIN SLIGHT CHANCE OF SHOWERS OVER THE
CASCADES HOWEVER...GIVEN BOTH THE POTENTIAL FOR SHOWERS TO WRAP
AROUND THE LOW AND SOME UNCERTAINTY IN THE EVOLUTION OF HOW FAR SOUTH
THE UPPER LOW MOVES. DAYTIME TEMPERATURES THURSDAY WILL BE CLOSER TO
SEASONAL NORMS...BEFORE WARMING INTO THE 70S INLAND AS HEIGHTS RISE
IN THE WARMING AIR MASS.  CULLEN

&&

.AVIATION...EXPECT PRIMARILY VFR CONDITIONS AT ALL INLAND TAF
SITES THROUGH 12Z TUESDAY AS OFFSHORE FLOW GIVES WAY TO
INCREASING ONSHORE FLOW LATE MONDAY. THE EXCEPTIONS TO THIS WILL
LIKELY BE ALONG THE COAST WHERE MARINE STRATUS APPROACHING THE
NORTH CALIFORNIA COAST WILL LIKELY ARRIVE BETWEEN 00Z AND 06Z
TUESDAY AND BRING A PERIOD OF IFR CONDITIONS. THERE IS A SLIGHT
CHANCE OF THUNDERSTORMS FROM ABOUT 21Z MON THRU 09Z TUE WITH THE
BEST CHANCES OVER THE MOUNTAINS. HOWEVER DUE TO ELEVATED INSTABILITY
AS WELL THERE IS A SMALL CHANCE ELSEWHERE.

KPDX AND APPROACHES...EXPECT VFR CONDITIONS THROUGH 12Z TUESDAY
AS OFFSHORE FLOW DECREASES OVER THE REGION. ANY THUNDERSTORMS THAT
DEVELOP WILL MOST LIKELY REMAIN AWAY FROM KPDX.

&&

.MARINE...A SOUTHERLY WIND REVERSAL IS WORKING NORTH ALONG THE
COAST. AS OF 2 AM SOUTH WINDS LESS THAN 10 KT HAVE REACHED NEWPORT
AND WILL EXTEND OVER THE REMAINDER OF THE WATERS THIS MORNING.
MODELS ARE INDICATING A PERIOD OF GUSTY 20 KT SOUTH WINDS THIS
MORNING PRIMARILY BETWEEN 10 AND 30 MILES OFFSHORE. A WESTERLY
SWELL SHOULD PUSH SEAS TEMPORARILY INTO THE 7 TO 9 FT RANGE
TODAY...BUT SEAS LOOK TO RELAX TUESDAY.

HIGH PRESSURE BUILDING BACK INTO THE NORTHEAST PACIFIC SHOULD
BRING NORTHERLY WINDS BACK ON TUESDAY WITH PERIODS OF GUSTY 25 TO
30 KT NORTHERLY WINDS DURING THE SECOND HALF OF NEXT WEEK AND
POSSIBLY NEXT WEEKEND AS WELL...PARTICULARLY ACROSS THE CENTRAL
OREGON WATERS. WHILE SEAS SHOULD GENERALLY REMAIN UNDER 10 FT FOR
MUCH OF THE NEXT WEEK...EXPECT SEAS TO BECOME ESPECIALLY STEEP AND
HAZARDOUS DURING THE SECOND HALF OF THE WEEK AS SEAS BECOME FRESH
SWELL/WIND DOMINATED DUE TO PERIODS OF NORTH-NORTHWESTERLY GALES
OFF VANCOUVER ISLAND. /MH /NEUMAN

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...NONE.

&&

$$

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 021032
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
331 AM PDT MON MAY  2 2016

.SYNOPSIS...ANOTHER WARM DAY IS ON TAP TODAY AS AN UPPER LEVEL RIDGE
REMAINS DOMINANT OVER WESTERN CANADA AND THE PAC NW. CHANGES WILL
BEGIN LATER TODAY AS A SLOW MOVING COLD FRONT INCHES TOWARD THE
COAST. THIS WILL TURN THE FLOW ALOFT MORE SOUTHERLY...BRINGING
MOISTURE AND INSTABILITY NORTHWARD FROM THE SIERRA NEVADA. THE RESULT
WILL BE INCREASING SHOWERS AND A CHANCE FOR THUNDER LATE THIS
AFTERNOON INTO TONIGHT. LOW-LEVEL FLOW WILL TURN ONSHORE...FIRST
COOLING OFF THE COAST TODAY...THEN INLAND AREAS TUESDAY. THE REMNANTS
OF THE FRONT AND ASSOCIATED UPPER TROUGH KEEP SHOWERS IN THE FORECAST
THROUGH THURSDAY...THEN FLOW TURNS OFFSHORE AGAIN FOR ANOTHER WARMING
AND DRYING TREND BY THE WEEKEND.

&&

.SHORT TERM...TODAY THROUGH WEDNESDAY...THIS MORNING IS STARTING OFF
QUITE WARM FOR MOST OF THE FORECAST AREA...WITH TEMPERATURES STILL IN
THE MID 50S TO MID 60S FOR ALL BUT THE MOST SHELTERED VALLEY
LOCATIONS. 850 MB TEMPS LOOK TO BE 1-2 DEG C WARMER THAN SUNDAY...
MEANWHILE GENERAL OFFSHORE FLOW CONTINUES THIS MORNING AS THERMAL LOW
PRESSURE LINGERS JUST OFF THE COAST. THIS SHOULD ALLOW TEMPS TO
EASILY CLIMB BACK INTO THE 80S TODAY FOR MOST INLAND VALLEYS...
POSSIBLY BREAKING A COUPLE RECORDS.

DECIDED TO BUMP UP FCST HIGHS A BIT ALONG THE COAST AS IT MAY TAKE A
FEW HOURS AFTER SUNRISE FOR THE SEABREEZE TO KICK IN. THE BULK OF THE
ANTICIPATED SOUTHERLY WIND REVERSAL IS JUST NOW APPROACHING CAPE
MENDOCINO IN NORTHERN CALIFORNIA...SO THAT WILL PROBABLY TAKE A FEW
HOURS TO ARRIVE ALONG THE CENTRAL OR COAST AS WELL. ON THE OTHER
HAND...THE SYNOPTIC-SCALE FORCING FOR OFFSHORE FLOW IS WANING AS
SPOKANE-NORTH BEND PRESSURE GRADIENTS ARE DOWN TO 4.3 MB AS OF 2 AM.
ALL THIS SHOULD ALLOW THERMAL LOW PRESSURE TO MIGRATE ONSHORE TODAY
BUT AFTER A SLIGHT DELAY...WITH ONSHORE FLOW RETURNING TO THE
IMMEDIATE COAST AND COASTAL VALLEYS BY EARLY AFTERNOON. AS A RESULT
HIGHS ALONG THE COAST TODAY SHOULD BE ABOUT 10 DEGREES COOLER THAN
YESTERDAY.

THE THERMAL TROUGH WILL TAKE SOME TIME TO CROSS THE COAST RANGE...
BUT SHOULD DO SO BY LATE AFTERNOON. THIS WILL BRING A PUSH OF MARINE
AIR FURTHER INLAND THIS EVENING...THE LEADING EDGE OF WHICH MAY SERVE
AS A TRIGGER FOR SURFACE-BASED CONVECTION DEPENDING ON WHICH MODEL
ONE BELIEVES. LATEST RUNS OF THE GFS...NAM...AND ECMWF DO SUGGEST
ABOUT 500-1000 J/KG OF SFC-BASED CAPE THIS AFTERNOON. MODELS HAVE
VARYING DEGREES OF CONVECTIVE INHIBITION...WITH THE 00Z GFS SHOWING
LITTLE WHILE THE NAM SHOWS AROUND 100 J/KG OF CIN FOR THE WILLAMETTE
VALLEY. MOST CONVECTIVE-ALLOWING MODELS SUGGEST CELLS WILL DEVELOP IN
THE LANE/DOUGLAS CASCADES SOMETIME AFTER 3 PM THIS AFTERNOON...WITH
SOME MODELS SHOWING ADDITIONAL CONVECTION DEVELOPING ON THE COAST
RANGE WITH THE LEADING EDGE OF THE MARINE PUSH. MODEL SOUNDINGS
SUGGEST FAIRLY HIGH BASES INITIALLY...WITH AS MUCH AS 1000 J/KG OF
DCAPE BUT FAIRLY WEAK SHEAR. THIS COULD CAUSE SOME OF THE STRONGER
CELLS TO PRODUCE STRONGER-THAN-USUAL OUTFLOW... PERHAPS GUSTS UP TO
30-40 MPH FROM SOME OF THE STRONGER CELLS. STEERING FLOW IS FROM THE
S-SE...WHICH COULD CAUSE SOME OF THE CELLS DEVELOPING IN THE CASCADES
TO DRIFT OVER THE WILLAMETTE VALLEY THIS EVENING. A SLOWLY
APPROACHING COLD FRONT MAY ALSO PROVIDE SOME ELEVATED INSTABILITY
OVERNIGHT...WHICH WOULD BRING A SLIGHT CHANCE OF THUNDER TO JUST
ABOUT ANYONE IN THE FORECAST AREA. HOWEVER LATEST MODEL RUNS HAVE
SEEMED TO BACK OFF ON THIS A BIT.

06Z NAM BOUNDARY LAYER RH INCREASES RAPIDLY ALONG THE COAST
TONIGHT...SUGGESTING FOG AND LOW CLOUDS WILL EVENTUALLY DEVELOP
BEHIND THE SOUTHERLY WIND REVERSAL. PRESSURE GRADIENTS TURN
INCREASINGLY ONSHORE TUESDAY AS THERMAL LOW PRESSURE SHIFTS EAST OF
THE CASCADES AND HIGHER PRESSURE BUILDS IN OFFSHORE. THIS SHOULD
BRING A 10-15 DEGREE COOLDOWN TO INLAND AREAS TUESDAY THEN ANOTHER
5-10 DEGREES FOR HIGHS IN THE LOWER TO MID 60S WED. THE REMNANTS OF
THE INCOMING COLD FRONT SHOULD PROVIDE ENOUGH MOISTURE FOR PLENTY OF
SHOWERS TUE/WED...ESPECIALLY IN THE HIGHER TERRAIN. THE STABILIZING
INFLUENCE OF ONSHORE FLOW AND THE MARINE LAYER WILL PROBABLY LIMIT
THUNDER TO NEAR THE CASCADE CREST AND AREAS EASTWARD TUESDAY AND
WEDNESDAY.  WEAGLE

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
WEDNESDAY NIGHT THROUGH SUNDAY. UPPER LEVEL TROUGH OVER THE EASTERN
PACIFIC JUST OFF THE NORTHERN CALIFORNIA COAST WILL REMAIN IN PLACE
THROUGH MUCH OF THE SECOND HALF OF THE WEEK BEFORE SLOWLY ADVANCING
INLAND INTO THE GREAT BASIN AND CUTTING OFF AS AN UPPER RIDGE NOSES
INTO THE PACIFIC NORTHWEST. SHOWERS SHOULD CONTINUE ACROSS THE AREA
ON THURSDAY...BUT TAPER OFF FOR MOST LOCATIONS ON FRIDAY AS THE
RIDGING BUILDS OVER THE REGION AND THE UPPER LOW MOVES FURTHER INTO
THE SOUTHWEST U.S. DID MAINTAIN SLIGHT CHANCE OF SHOWERS OVER THE
CASCADES HOWEVER...GIVEN BOTH THE POTENTIAL FOR SHOWERS TO WRAP
AROUND THE LOW AND SOME UNCERTAINTY IN THE EVOLUTION OF HOW FAR SOUTH
THE UPPER LOW MOVES. DAYTIME TEMPERATURES THURSDAY WILL BE CLOSER TO
SEASONAL NORMS...BEFORE WARMING INTO THE 70S INLAND AS HEIGHTS RISE
IN THE WARMING AIR MASS.  CULLEN

&&

.AVIATION...EXPECT PRIMARILY VFR CONDITIONS AT ALL INLAND TAF
SITES THROUGH 12Z TUESDAY AS OFFSHORE FLOW GIVES WAY TO
INCREASING ONSHORE FLOW LATE MONDAY. THE EXCEPTIONS TO THIS WILL
LIKELY BE ALONG THE COAST WHERE MARINE STRATUS APPROACHING THE
NORTH CALIFORNIA COAST WILL LIKELY ARRIVE BETWEEN 00Z AND 06Z
TUESDAY AND BRING A PERIOD OF IFR CONDITIONS. THERE IS A SLIGHT
CHANCE OF THUNDERSTORMS FROM ABOUT 21Z MON THRU 09Z TUE WITH THE
BEST CHANCES OVER THE MOUNTAINS. HOWEVER DUE TO ELEVATED INSTABILITY
AS WELL THERE IS A SMALL CHANCE ELSEWHERE.

KPDX AND APPROACHES...EXPECT VFR CONDITIONS THROUGH 12Z TUESDAY
AS OFFSHORE FLOW DECREASES OVER THE REGION. ANY THUNDERSTORMS THAT
DEVELOP WILL MOST LIKELY REMAIN AWAY FROM KPDX.

&&

.MARINE...A SOUTHERLY WIND REVERSAL IS WORKING NORTH ALONG THE
COAST. AS OF 2 AM SOUTH WINDS LESS THAN 10 KT HAVE REACHED NEWPORT
AND WILL EXTEND OVER THE REMAINDER OF THE WATERS THIS MORNING.
MODELS ARE INDICATING A PERIOD OF GUSTY 20 KT SOUTH WINDS THIS
MORNING PRIMARILY BETWEEN 10 AND 30 MILES OFFSHORE. A WESTERLY
SWELL SHOULD PUSH SEAS TEMPORARILY INTO THE 7 TO 9 FT RANGE
TODAY...BUT SEAS LOOK TO RELAX TUESDAY.

HIGH PRESSURE BUILDING BACK INTO THE NORTHEAST PACIFIC SHOULD
BRING NORTHERLY WINDS BACK ON TUESDAY WITH PERIODS OF GUSTY 25 TO
30 KT NORTHERLY WINDS DURING THE SECOND HALF OF NEXT WEEK AND
POSSIBLY NEXT WEEKEND AS WELL...PARTICULARLY ACROSS THE CENTRAL
OREGON WATERS. WHILE SEAS SHOULD GENERALLY REMAIN UNDER 10 FT FOR
MUCH OF THE NEXT WEEK...EXPECT SEAS TO BECOME ESPECIALLY STEEP AND
HAZARDOUS DURING THE SECOND HALF OF THE WEEK AS SEAS BECOME FRESH
SWELL/WIND DOMINATED DUE TO PERIODS OF NORTH-NORTHWESTERLY GALES
OFF VANCOUVER ISLAND. /MH /NEUMAN

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...NONE.

&&

$$

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 020359
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
859 PM PDT SUN MAY  1 2016

.SYNOPSIS...A STRONG UPPER HIGH WAS CENTERED OVER SOUTHWEST CANADA
THIS EVENING AND WILL CONTINUE TO BRING WARM DRY WEATHER WITH SOME
OFFSHORE FLOW TO SOUTHWEST WASHINGTON AND NORTHWEST OREGON INTO
MONDAY. THE PATTERN WILL BEGIN TO BREAK DOWN MONDAY AFTERNOON AS A
PACIFIC FRONT SLOWLY APPROACHES THE COAST. MOISTURE AND INSTABILITY
WILL SPREAD NORTHWARD INTO THE FORECAST AREA LATE MONDAY AND MONDAY
NIGHT INTO TUESDAY UNDER DEVELOPING SOUTHERLY FLOW ALOFT. COOLER
MARINE AIR WILL SPREAD NORTH ALONG THE COAST MONDAY...START TO MOVE
INLAND MONDAY NIGHT AND TUESDAY. THE MAIN FRONT IS FORECAST TO THEN
MOVE ONSHORE FROM THE WEST TUESDAY NIGHT INTO EARLY WEDNESDAY. THE
ASSOCIATED COOL UPPER TROUGH WILL CONTINUE TO BRING UNSETTLED WEATHER
OVER THE FORECAST AREA WEDNESDAY AND THURSDAY. EXPECT ANOTHER WARMING
AND DRYING TREND DEVELOPING BY THE WEEKEND.
&&

.SHORT TERM...AN UPPER HIGH THAT IS CENTERED OVER SOUTHWEST CANADA
BROUGHT WARM DRY WEATHER TO SOUTHWEST WASHINGTON AND NORTHWEST OREGON
TODAY AS TEMPS REACHED NEAR 80 BOTH INLAND AND AT THE COAST. OFFSHORE
WINDS AIDED THE WARM UP WITH A THERMAL TROUGH NEAR THE COAST. THE
ONLY RECORDS TIED OR BROKEN TODAY WERE 81 AT BOTH ASTORIA AND
NEWPORT.

EXPECT ONE MORE UNSEASONABLY WARM DAY MONDAY INLAND...BUT MOST
RECORDS ARE LIKELY OUT OF REACH EXCEPT PERHAPS AT TROUTDALE...
HILLSBORO...AND MCMINNVILLE.

CHANGES ARE COMING THOUGH. THE COAST SHOULD BE TURNING COOLER MONDAY
AS SOME MARINE AIR AND POSSIBLY SOME LOWER CLOUDS SPREAD NORTH DURING
THE DAY... WITH A DISTINCT SEA BREEZE IN THE AFTERNOON. SOUTHERLY
FLOW ALOFT AHEAD OF THE NEXT APPROACHING SYSTEM IS FORECAST TO SPREAD
MOISTURE AND INSTABILITY NORTHWARD THROUGH NORTHWEST OREGON AND
SOUTHWEST WASHINGTON LATER MONDAY AND ESPECIALLY MONDAY NIGHT.
ONSHORE FLOW INCREASES INLAND AS WELL BY TUESDAY SO THAT TUESDAY
SHOULD BE COOLER. MARINE CLOUDS MAY NOT BE VERY SOLID TUESDAY...WITH
THE MAIN CLOUDS BEING CONVECTIVE DEBRIS THAT COULD RESULT IN MORE
SHOWERS AND POSSIBLY A THUNDERSTORM AGAIN...THOUGH THE BEST CHANCE OF
THUNDER TUESDAY IS INCREASINGLY LOOKING LIKE THE HIGHER CASCADES.

THE FRONT ASSOCIATED WITH THE OFFSHORE SYSTEM IS FORECAST TO MOVE
ONSHORE TUESDAY NIGHT AND EARLY WEDNESDAY. THE FRONT DOES NOT LOOK
LIKE A REAL SOLID WINTER TYPE FRONT...SO IT LOOKS LIKE IT WILL MAINLY
INCREASE THE SHOWER COVERAGE OVER THE FORECAST AREA TUESDAY NIGHT AND
WEDNESDAY. THE ONSHORE FLOW LOOKS STRONG ENOUGH THAT THE CHANCE OF
THUNDER LOOKS PRETTY MINIMAL WEDNESDAY. TOLLESON

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
WEDNESDAY NIGHT THROUGH SUNDAY. UPPER LEVEL TROUGH OVER THE EASTERN
PACIFIC JUST OFF THE NORTHERN CALIFORNIA COAST WILL REMAIN IN PLACE
THROUGH MUCH OF THE SECOND HALF OF THE WEEK BEFORE SLOWLY ADVANCING
INLAND INTO THE GREAT BASIN AND CUTTING OFF AS AN UPPER RIDGE NOSES
INTO THE PACIFIC NORTHWEST. SHOWERS SHOULD CONTINUE ACROSS THE AREA
ON THURSDAY...BUT TAPER OFF FOR MOST LOCATIONS ON FRIDAY AS THE
RIDGING BUILDS OVER THE REGION AND THE UPPER LOW MOVES FURTHER INTO
THE SOUTHWEST U.S. DID MAINTAIN SLIGHT CHANCE OF SHOWERS OVER THE
CASCADES HOWEVER...GIVEN BOTH THE POTENTIAL FOR SHOWERS TO WRAP
AROUND THE LOW AND SOME UNCERTAINTY IN THE EVOLUTION OF HOW FAR SOUTH
THE UPPER LOW MOVES. DAYTIME TEMPERATURES THURSDAY WILL BE CLOSER TO
SEASONAL NORMS...BEFORE WARMING INTO THE 70S INLAND AS HEIGHTS RISE
IN THE WARMING AIR MASS. CULLEN
&&

.AVIATION...EXPECT PRIMARILY VFR CONDITIONS AT ALL TAF SITES THROUGH
06Z TUESDAY AS OFFSHORE FLOW GIVES WAY TO INCREASING ONSHORE FLOW
LATE MONDAY. THE LONE EXCEPTION TO THIS WILL LIKELY BE AT KONP WHERE
MARINE STRATUS CURRENTLY NEAR THE BAY AREA OF CALIFORNIA WILL LIKELY
ARRIVE BETWEEN 00Z AND 06Z TUESDAY AND BRING A PERIOD OF IFR
CONDITIONS.

KPDX AND APPROACHES...EXPECT VFR CONDITIONS THROUGH 06Z TUESDAY AS
OFFSHORE FLOW DECREASES OVER THE REGION. /NEUMAN
&&

.MARINE...A SOUTHERLY WIND REVERSAL WILL WORK ITS WAY UP THE COAST
OVERNIGHT AND MONDAY WITH A PERIOD OF GUSTY 20 KT SOUTH WINDS. THERE
IS A CHANCE WINDS COULD SPIKE UP TO 25 KT BRIEFLY...BUT DO NOT THINK
IT WILL BE PROLONGED ENOUGH TO WARRANT A SMALL CRAFT ADVISORY FOR
WINDS. A WESTERLY SWELL SHOULD PUSH SEAS TEMPORARILY INTO THE 7 TO 9
FT RANGE ON MONDAY...BUT SEAS LOOK TO RELAX TUESDAY.

HIGH PRESSURE BUILDING BACK INTO THE NORTHEAST PACIFIC SHOULD BRING
NORTHERLY WINDS BACK ON TUESDAY WITH PERIODS OF GUSTY 25 TO 30 KT
NORTHERLY WINDS DURING THE SECOND HALF OF NEXT WEEK AND POSSIBLY NEXT
WEEKEND AS WELL...PARTICULARLY ACROSS THE CENTRAL OREGON WATERS.
WHILE SEAS SHOULD GENERALLY REMAIN UNDER 10 FT FOR MUCH OF THE NEXT
WEEK...EXPECT SEAS TO BECOME ESPECIALLY STEEP AND HAZARDOUS DURING
THE SECOND HALF OF THE WEEK AS SEAS BECOME FRESH SWELL/WIND DOMINATED
DUE TO PERIODS OF NORTH-NORTHWESTERLY GALES OFF VANCOUVER ISLAND.
/NEUMAN
&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...NONE.

&&

$$

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 012132
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
230 PM PDT SUN MAY  1 2016

.SYNOPSIS...A STRONG RIDGE OF HIGH PRESSURE RESIDES OVER WESTERN
CANADA AND THERMAL LOW PRESSURE ALONG THE COAST. THIS PATTERN WILL
CONTINUE TO BRING ABOVE NORMAL TEMPERATURES AT INLAND LOCATIONS. THE
PATTERN WILL BEGIN TO BREAK DOWN MONDAY AFTERNOON AS A PACIFIC FRONT
SLOWLY APPROACHES THE COAST. THIS WILL BRING MUCH COOLER AIR TO THE
COAST MONDAY...THEN SPREAD THE COOLER AIR INLAND TUESDAY AND
WEDNESDAY. SHOWER CHANCES WILL INCREASE AS THE FRONT APPROACHES WITH
ISOLATED THUNDERSTORMS POSSIBLE FOR MUCH OF THE FORECAST AREA LATE
MONDAY AND TUESDAY. SHOWERS CONTINUE INTO MIDWEEK...THEN EXPECT
ANOTHER WARMING AND DRYING TREND DEVELOPING BY THE WEEKEND.

&&

.SHORT TERM...HIGH PRESSURE OVER WESTERN CANADA AND THERMAL LOW
PRESSURE BUILDING ALONG THE COAST IS BRINGING OFFSHORE FLOW AND
PLEASANT SPRING WEATHER TO THE REGION. TEMPERATURES TODAY WILL TOP
OUT AROUND 15 DEGREES ABOVE NORMAL TODAY AT BOTH INLAND AND COASTAL
LOCATIONS. INLAND TEMPERATURES WILL BE WARM AGAIN MONDAY WITH 3 OR 4
DEGREES WARMER THAN TODAYS READINGS. TEMPERATURES ALONG THE COAST
MONDAY WILL RETURN TO SEASONAL NORMALS AS SOUTHWEST FLOW BRINGS A
SURGE OF COOL MARINE AIR TO THE COASTAL STRIP.

THE THERMAL LOW ALONG THE COAST WILL PUSH OFFSHORE TONIGHT AND LIFT
NORTHWARD OFF THE COAST AS A CLOSED THERMAL LOW MONDAY. AS THE LOW
SHIFTS NORTHWARD...MODELS SHOW A SOUTHERLY WIND REVERSAL SPREADING
UP THE COAST BEHIND THE THERMAL LOW DURING THE DAY ON MONDAY.  THE
SOUTHERLY WIND REVERSAL WILL TYPICALLY DRAG SOME LOW CLOUDS AND FOG
ALONG THE COASTAL STRIP...BUT NOT VERY CONFIDENT IN THAT SCENARIO
FOR MONDAY AS THE DECK OF LOW CLOUDS REMAINS OFF THE CENTRAL CA
COAST AT THIS TIME. MUCH BETTER CHANCE FOR COASTAL STRATUS AND FOG
ON TUESDAY AS THE FRONT APPROACHES AND ONSHORE FLOW STRENGTHENS.
NONETHELESS...THE SWITCH TO S-SW FLOW WILL USHER IN COOL AIR FOR THE
THE COASTAL REGION MONDAY AND TUESDAY WITH TEMPERATURES BACK TO
SEASONAL NORMALS.

BY MONDAY AFTERNOON...MODELS SHOW ENOUGH INSTABILITY AND MOISTURE
MOVING INTO THE AREA FOR THE THREAT OF CONVECTION.  THE BEST CHANCE
FOR THUNDER WILL BE ALONG THE CASCADES WHERE THE ELEVATED HEAT SOURCE
CAN BREAK A WEAK CAP. THERE IS ALSO SOME INSTABILITY AND A FAIR AMOUNT
OF CAPE IN THE VALLEY MONDAY COUPLED WITH S-SE STEERING FLOW...SO
THERE IS ALSO A THREAT OF TSTORMS IN THE VALLEY MONDAY EVENING AND
MONDAY NIGHT.

TUESDAY WILL BE A TRANSITION DAY BACK TO MORE SEASONAL EARLY MAY
WEATHER AS ONSHORE FLOW RETURNS. THIS SHOULD RESULT IN A 10-15
DEGREE COOL DOWN FOR INLAND LOCATIONS TUESDAY. INCREASING LOW-LEVEL
MOISTURE AND THE APPROACH OF THE FRONT WILL LIKELY KICK OFF MORE
SHOWER ACTIVITY AND THREAT OF CONVECTION TUESDAY. TW

.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY. UPPER LEVEL TROUGH
OVER THE EASTERN PACIFIC JUST OFF THE NORTHERN CALIFORNIA COAST WILL
REMAIN IN PLACE THROUGH MUCH OF THE SECOND HALF OF THE WEEK BEFORE
SLOWLY ADVANCING INLAND INTO THE GREAT BASIN AND CUTTING OFF AS AN
UPPER RIDGE NOSES INTO THE PACIFIC NORTHWEST. SHOWERS SHOULD
CONTINUE ACROSS THE AREA ON THURSDAY...BUT TAPER OFF FOR MOST
LOCATIONS ON FRIDAY AS THE RIDGING BUILDS OVER THE REGION AND THE
UPPER LOW MOVES FURTHER INTO THE SOUTHWEST U.S. DID MAINTAIN SLIGHT
CHANCE OF SHOWERS OVER THE CASCADES HOWEVER...GIVEN BOTH THE
POTENTIAL FOR SHOWERS TO WRAP AROUND THE LOW AND SOME UNCERTAINTY IN
THE EVOLUTION OF HOW FAR SOUTH THE UPPER LOW MOVES. DAYTIME
TEMPERATURES THURSDAY WILL BE CLOSER TO SEASONAL NORMS...BEFORE
WARMING INTO THE 70S INLAND AS HEIGHTS RISE IN THE WARMING AIR MASS.
CULLEN
&&

.AVIATION...OFFSHORE FLOW WILL BRING VFR CONDITIONS TO ALL TAF
SITES OVER THE NEXT 24 HOURS. IFR STRATUS MAY REACH KONP SOMETIME
ON MONDAY BUT IT IS LOOKING LIKE IT WILL BE LATER IN THE DAY
RATHER THAN EARLIER. GUSTY OFFSHORE WINDS THIS AFTERNOON WILL
DECREASE TONIGHT.

KPDX AND APPROACHES...OFFSHORE FLOW WILL BRING VFR CONDITIONS
THROUGH MONDAY. GUSTY OFFSHORE WINDS THIS AFTERNOON WILL
DECREASE BY ABOUT 12Z MONDAY. BOWEN

&&

.MARINE...A THERMAL TROUGH OVER THE SOUTH OREGON COAST CONTINUES
TO WEAKEN WITH EASING WINDS OVER THE WATERS. WILL SEE SOME
POTENTIAL FOR GUSTS TO 25 KT OFF COASTAL GAPS THIS AFTERNOON AND
EVENING DUE TO OFFSHORE FLOW...BUT WILL LIKELY BE TOO LOCALIZED
FOR A SMALL CRAFT ADVISORY. NONETHELESS...MARINERS SHOULD BE AWARE
OF THESE INCREASED WINDS NEAR COASTAL GAPS. SEAS WILL REMAIN
AROUND 6 TO 7 FT THROUGH TONIGHT BEFORE POSSIBLY INCREASING TO 8
FT MONDAY WITH WEST SWELL. NEXT OPPORTUNITY FOR SEAS TO RISE TO 10
FT WILL NOT BE UNTIL AT LEAST WEDNESDAY AFTERNOON.

THE THERMAL TROUGH SHIFTS OFF THE COASTLINE AND OVER THE WATERS
LATER TODAY...SETTING UP FOR A SOUTHERLY WIND REVERSAL TO PUSH UP
THE COAST MONDAY WHICH COULD BRIEFLY BRING A PERIOD OF 20 TO 25
KT WIND GUSTS LATE MONDAY MORNING OR MONDAY AFTERNOON. NOT A
CLEAR SIGNAL FOR ADVISORY AT THIS TIME BUT WILL HAVE TO MONITOR.
OTHERWISE...AN UPPER LEVEL TROUGH SPLITTING AND HEADING SOUTH OF
THE REGION SHOULD BRING A RETURN TO A NORTHERLY WIND PATTERN
TOWARDS THE MIDDLE OF NEXT WEEK WITH SMALL CRAFT ADVISORY LEVEL
WIND GUSTS OF 25 TO 30 KT POSSIBLE. HIGH PRESSURE THEN MAY SHIFT
MORE SQUARELY OVER THE NORTHEAST PACIFIC LATE IN THE WEEK AND
FOCUS NORTHERLY WINDS ACROSS THE CENTRAL OREGON WATERS. BOWEN

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...NONE.

&&

$$

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 012132
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
230 PM PDT SUN MAY  1 2016

.SYNOPSIS...A STRONG RIDGE OF HIGH PRESSURE RESIDES OVER WESTERN
CANADA AND THERMAL LOW PRESSURE ALONG THE COAST. THIS PATTERN WILL
CONTINUE TO BRING ABOVE NORMAL TEMPERATURES AT INLAND LOCATIONS. THE
PATTERN WILL BEGIN TO BREAK DOWN MONDAY AFTERNOON AS A PACIFIC FRONT
SLOWLY APPROACHES THE COAST. THIS WILL BRING MUCH COOLER AIR TO THE
COAST MONDAY...THEN SPREAD THE COOLER AIR INLAND TUESDAY AND
WEDNESDAY. SHOWER CHANCES WILL INCREASE AS THE FRONT APPROACHES WITH
ISOLATED THUNDERSTORMS POSSIBLE FOR MUCH OF THE FORECAST AREA LATE
MONDAY AND TUESDAY. SHOWERS CONTINUE INTO MIDWEEK...THEN EXPECT
ANOTHER WARMING AND DRYING TREND DEVELOPING BY THE WEEKEND.

&&

.SHORT TERM...HIGH PRESSURE OVER WESTERN CANADA AND THERMAL LOW
PRESSURE BUILDING ALONG THE COAST IS BRINGING OFFSHORE FLOW AND
PLEASANT SPRING WEATHER TO THE REGION. TEMPERATURES TODAY WILL TOP
OUT AROUND 15 DEGREES ABOVE NORMAL TODAY AT BOTH INLAND AND COASTAL
LOCATIONS. INLAND TEMPERATURES WILL BE WARM AGAIN MONDAY WITH 3 OR 4
DEGREES WARMER THAN TODAYS READINGS. TEMPERATURES ALONG THE COAST
MONDAY WILL RETURN TO SEASONAL NORMALS AS SOUTHWEST FLOW BRINGS A
SURGE OF COOL MARINE AIR TO THE COASTAL STRIP.

THE THERMAL LOW ALONG THE COAST WILL PUSH OFFSHORE TONIGHT AND LIFT
NORTHWARD OFF THE COAST AS A CLOSED THERMAL LOW MONDAY. AS THE LOW
SHIFTS NORTHWARD...MODELS SHOW A SOUTHERLY WIND REVERSAL SPREADING
UP THE COAST BEHIND THE THERMAL LOW DURING THE DAY ON MONDAY.  THE
SOUTHERLY WIND REVERSAL WILL TYPICALLY DRAG SOME LOW CLOUDS AND FOG
ALONG THE COASTAL STRIP...BUT NOT VERY CONFIDENT IN THAT SCENARIO
FOR MONDAY AS THE DECK OF LOW CLOUDS REMAINS OFF THE CENTRAL CA
COAST AT THIS TIME. MUCH BETTER CHANCE FOR COASTAL STRATUS AND FOG
ON TUESDAY AS THE FRONT APPROACHES AND ONSHORE FLOW STRENGTHENS.
NONETHELESS...THE SWITCH TO S-SW FLOW WILL USHER IN COOL AIR FOR THE
THE COASTAL REGION MONDAY AND TUESDAY WITH TEMPERATURES BACK TO
SEASONAL NORMALS.

BY MONDAY AFTERNOON...MODELS SHOW ENOUGH INSTABILITY AND MOISTURE
MOVING INTO THE AREA FOR THE THREAT OF CONVECTION.  THE BEST CHANCE
FOR THUNDER WILL BE ALONG THE CASCADES WHERE THE ELEVATED HEAT SOURCE
CAN BREAK A WEAK CAP. THERE IS ALSO SOME INSTABILITY AND A FAIR AMOUNT
OF CAPE IN THE VALLEY MONDAY COUPLED WITH S-SE STEERING FLOW...SO
THERE IS ALSO A THREAT OF TSTORMS IN THE VALLEY MONDAY EVENING AND
MONDAY NIGHT.

TUESDAY WILL BE A TRANSITION DAY BACK TO MORE SEASONAL EARLY MAY
WEATHER AS ONSHORE FLOW RETURNS. THIS SHOULD RESULT IN A 10-15
DEGREE COOL DOWN FOR INLAND LOCATIONS TUESDAY. INCREASING LOW-LEVEL
MOISTURE AND THE APPROACH OF THE FRONT WILL LIKELY KICK OFF MORE
SHOWER ACTIVITY AND THREAT OF CONVECTION TUESDAY. TW

.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY. UPPER LEVEL TROUGH
OVER THE EASTERN PACIFIC JUST OFF THE NORTHERN CALIFORNIA COAST WILL
REMAIN IN PLACE THROUGH MUCH OF THE SECOND HALF OF THE WEEK BEFORE
SLOWLY ADVANCING INLAND INTO THE GREAT BASIN AND CUTTING OFF AS AN
UPPER RIDGE NOSES INTO THE PACIFIC NORTHWEST. SHOWERS SHOULD
CONTINUE ACROSS THE AREA ON THURSDAY...BUT TAPER OFF FOR MOST
LOCATIONS ON FRIDAY AS THE RIDGING BUILDS OVER THE REGION AND THE
UPPER LOW MOVES FURTHER INTO THE SOUTHWEST U.S. DID MAINTAIN SLIGHT
CHANCE OF SHOWERS OVER THE CASCADES HOWEVER...GIVEN BOTH THE
POTENTIAL FOR SHOWERS TO WRAP AROUND THE LOW AND SOME UNCERTAINTY IN
THE EVOLUTION OF HOW FAR SOUTH THE UPPER LOW MOVES. DAYTIME
TEMPERATURES THURSDAY WILL BE CLOSER TO SEASONAL NORMS...BEFORE
WARMING INTO THE 70S INLAND AS HEIGHTS RISE IN THE WARMING AIR MASS.
CULLEN
&&

.AVIATION...OFFSHORE FLOW WILL BRING VFR CONDITIONS TO ALL TAF
SITES OVER THE NEXT 24 HOURS. IFR STRATUS MAY REACH KONP SOMETIME
ON MONDAY BUT IT IS LOOKING LIKE IT WILL BE LATER IN THE DAY
RATHER THAN EARLIER. GUSTY OFFSHORE WINDS THIS AFTERNOON WILL
DECREASE TONIGHT.

KPDX AND APPROACHES...OFFSHORE FLOW WILL BRING VFR CONDITIONS
THROUGH MONDAY. GUSTY OFFSHORE WINDS THIS AFTERNOON WILL
DECREASE BY ABOUT 12Z MONDAY. BOWEN

&&

.MARINE...A THERMAL TROUGH OVER THE SOUTH OREGON COAST CONTINUES
TO WEAKEN WITH EASING WINDS OVER THE WATERS. WILL SEE SOME
POTENTIAL FOR GUSTS TO 25 KT OFF COASTAL GAPS THIS AFTERNOON AND
EVENING DUE TO OFFSHORE FLOW...BUT WILL LIKELY BE TOO LOCALIZED
FOR A SMALL CRAFT ADVISORY. NONETHELESS...MARINERS SHOULD BE AWARE
OF THESE INCREASED WINDS NEAR COASTAL GAPS. SEAS WILL REMAIN
AROUND 6 TO 7 FT THROUGH TONIGHT BEFORE POSSIBLY INCREASING TO 8
FT MONDAY WITH WEST SWELL. NEXT OPPORTUNITY FOR SEAS TO RISE TO 10
FT WILL NOT BE UNTIL AT LEAST WEDNESDAY AFTERNOON.

THE THERMAL TROUGH SHIFTS OFF THE COASTLINE AND OVER THE WATERS
LATER TODAY...SETTING UP FOR A SOUTHERLY WIND REVERSAL TO PUSH UP
THE COAST MONDAY WHICH COULD BRIEFLY BRING A PERIOD OF 20 TO 25
KT WIND GUSTS LATE MONDAY MORNING OR MONDAY AFTERNOON. NOT A
CLEAR SIGNAL FOR ADVISORY AT THIS TIME BUT WILL HAVE TO MONITOR.
OTHERWISE...AN UPPER LEVEL TROUGH SPLITTING AND HEADING SOUTH OF
THE REGION SHOULD BRING A RETURN TO A NORTHERLY WIND PATTERN
TOWARDS THE MIDDLE OF NEXT WEEK WITH SMALL CRAFT ADVISORY LEVEL
WIND GUSTS OF 25 TO 30 KT POSSIBLE. HIGH PRESSURE THEN MAY SHIFT
MORE SQUARELY OVER THE NORTHEAST PACIFIC LATE IN THE WEEK AND
FOCUS NORTHERLY WINDS ACROSS THE CENTRAL OREGON WATERS. BOWEN

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...NONE.

&&

$$

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 011654
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
950 AM PDT SUN MAY  1 2016

.SYNOPSIS...A STRONG RIDGE OF HIGH PRESSURE RESIDES OVER WESTERN
CANADA AND A BROAD UPPER LOW OVER THE INTERMOUNTAIN REGION AND
SOUTHWESTERN U.S. THIS PATTERN WILL USHER IN WARM OFFSHORE FLOW
TODAY...WITH TEMPERATURES WELL ABOVE NORMAL AT INLAND LOCATIONS AND
THE COAST.  THIS PATTERN BEGINS TO BREAK DOWN MONDAY AS A PACIFIC
COLD FRONT SLOWLY APPROACHES THE COAST. THIS SHOULD COOL DOWN THE
COAST MONDAY...WITH COOLER TEMPERATURES SPREADING INLAND TUESDAY AND
WEDNESDAY. SHOWER CHANCES WILL INCREASE AS THE FRONT APPROACHES...
WITH ISOLATED THUNDERSTORMS POSSIBLE FOR MUCH OF THE FORECAST AREA
LATE MONDAY INTO TUESDAY. SHOWERS CONTINUE INTO MIDWEEK...THEN
MODELS HINT AT ANOTHER WARMING AND DRYING TREND DEVELOPING BY NEXT
WEEKEND.

&&

.SHORT TERM...SATELLITE IMAGERY SHOWS CLEAR SKIES AROUND THE REGION
THIS MORNING. THE EXCEPTION IS SOME CUMULUS DEVELOPING ALONG THE
OREGON CASCADES FROM ABOUT DETROIT SOUTHWARD. AN UNSEASONABLY STRONG
UPPER LEVEL RIDGE OF HIGH PRESSURE REMAINS OVER WESTERN CANADA AND A
BROAD UPPER LOW SITS OVER THE INTERMOUNTAIN AND SOUTHWEST US. A
THERMAL LOW WILL ALSO BUILD NORTHWARD ALONG THE COAST TODAY.
OVERALL...EXPECT VERY PLEASANT SPRING WEATHER TODAY WITH
TEMPERATURES IN THE MID 70S TO AROUND 80. THE COASTAL REGION SHOULD
ALSO SEE TEMPS NEAR 80 THIS AFTERNOON AS WE HAVE DEEP EASTERLY FLOW
OVER THE REGION.

THE THERMAL LOW ALONG THE COAST WILL PUSH OFFSHORE TONIGHT AND LIFT
NORTHWARD OFF THE COAST AS A CLOSED THERMAL LOW MONDAY. AS THE LOW
SHIFTS NORTHWARD...MODELS SHOW A SOUTHERLY WIND REVERSAL SPREADING
UP THE COAST BEHIND THE THERMAL LOW DURING THE DAY ON MONDAY. AT
THIS TIME...THERE IS VERY LITTLE STRATUS ALONG THE CA COAST...SO IT
IS HARD TO TELL JUST HOW MUCH FOG AND LOW CLOUDS WILL ACCOMPANY THE
WIND REVERSAL. WILL LOOK AT THIS MORE CLOSELY THIS AFTERNOON.
NONETHELESS...THE SWITCH TO S-SW FLOW WILL COOL THE COAST
CONSIDERABLY ON MONDAY AND TUESDAY.

BY MONDAY AFTERNOON...MODELS SHOW ENOUGH INSTABILITY AND MOISTURE
ARRIVING FOR THE THREAT OF CONVECTION. AS USUAL...THE BEST CHANCE
FOR THUNDER WILL BE ALONG THE CASCADES WHERE THE ELEVATED HEAT SOURCE
CAN BREAK A WEAK CAP. THERE IS ALSO SOME INSTABILTY AND A FAIR AMOUNT
OF CAPE IN THE VALLEY MON COUPLED WITH S-SE STEERING FLOW...SO THERE
IS ALSO A THREAT OF TSTORMS IN THE VALLEY MONDAY EVENING AND MONDAY
NIGHT.

TUESDAY WILL BE A TRANSITION DAY BACK TO MORE SEASONAL EARLY MAY
WEATHER AS ONSHORE FLOW RETURNS. THIS SHOULD RESULT IN A 10-15 DEGREE
COOLDOWN INLAND TUESDAY. INCREASING LOW-LEVEL MOISTURE AND THE
APPROACH OF THE FRONT WILL LIKELY KICK OFF MORE SHOWER ACTIVITY
TUESDAY. TW

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
TUESDAY NIGHT THROUGH SATURDAY. BROAD UPPER TROUGH REMAINS OVER THE
EASTERN PACIFIC JUST OFF THE CALIFORNIA COAST...PROVIDING FOR SOUTH
TO SOUTHWEST FLOW ALOFT OVER THE REGION. THIS WILL KEEP SHOWER
CHANCES IN PLACE THROUGH THURSDAY. THUNDER CHANCES TUESDAY NIGHT AND
WEDNESDAY AFTERNOON/EVENING WILL BE GREATEST IN THE CASCADES AND
FOOTHILLS...BUT LATEST MODELS SUGGEST ENOUGH INSTABILITY TO KEEP A
SLIGHT CHANCE MENTION FOR THE WILLAMETTE VALLEY. MAY NOT BE ENOUGH OF
A TRIGGER TO TAP INTO THIS...BUT GIVEN THE POTENTIAL IN THE MODEL
SOUNDINGS FEEL A SLIGHT CHANCE REMAINS WARRANTED. EXPECT SOME WARMING
ON FRIDAY AND SATURDAY...WITH PERHAPS SOME DRY CONDITIONS... AS THE
UPPER LOW MIGRATES EASTWARD INTO THE GREAT BASIN AND HIGH PRESSURE
BUILDING INTO THE GULF OF ALASKA AS REX BLOCK DEVELOPS OVER THE
REGION. HOWEVER...MAINTAINED THE FORECAST ALONG THE LINES SUGGESTED
BY A BLEND OF MODELS AS THE ECMWF CONTINUES TO REMAIN WITH A MORE WET
SOLUTION AND SOME SPREAD IN THE GFS ENSEMBLE MEMBERS.

&&

.AVIATION...INCREASING OFFSHORE FLOW WILL BRING VFR CONDITIONS TO
ALL TAF SITES THROUGH 12Z MONDAY. HOWEVER THERE IS INCREASING
CHANCES FOR IFR STRATUS TO REACH KONP CLOSE TO 12Z MON BUT WILL
NOT INCLUDE IN FORECAST AT THIS TIME. 5SM VISIBILITY AT KAST
STILL SEEMS SUSPICIOUS BASED ON WEB CAMERAS SO KEPT THEM VFR EVEN
THOUGH THE OBSERVATIONS SUGGEST OTHERWISE.

KPDX AND APPROACHES...INCREASING OFFSHORE FLOW WILL BRING VFR
CONDITIONS THROUGH 12Z MONDAY. EASTERLY WINDS WILL INCREASE MIDDAY
WITH GUSTS TO 25 KT OVER EASTERN APPROACHES THROUGH EARLY
EVENING. BOWEN/MH

&&

.MARINE...A THERMAL TROUGH OVER THE SOUTH OREGON COAST WILL WEAKEN
THIS MORNING WITH WINDS CONTINUING TO EASE OVER THE WATERS. WINDS
HAVE DROPPED BELOW 20 KT AND DOMINANT PERIODS HAVE REBOUNDED AS A
RESULT...BACK UP TO 12 TO 14 SECONDS. WILL LET THE SMALL CRAFT
ADVISORY FOR SEAS EXPIRE AS SEAS ARE NO LONGER SQUARE AND SHOULD
REMAIN 6 TO 8 FT TODAY. WILL ALSO CANCEL THE ADVISORY FOR WINDS.
WILL SEE SOME POTENTIAL FOR GUSTS TO 25 KT OFF COASTAL GAPS THIS
AFTERNOON AND EVENING DUE TO OFFSHORE FLOW...BUT WILL LIKELY BE
TOO LOCALIZED FOR A SMALL CRAFT ADVISORY. NONETHELESS...MARINERS
SHOULD BE AWARE OF THESE INCREASED WINDS NEAR COASTAL GAPS.

THE THERMAL TROUGH SHIFTS OFF THE COASTLINE AND OVER THE WATERS
TODAY...SETTING UP FOR A SOUTHERLY WIND REVERSAL TO PUSH UP THE
COAST TONIGHT INTO MONDAY WHICH COULD BRIEFLY BRING A PERIOD OF
20 TO 25 KT WIND GUSTS. NOT A CLEAR SIGNAL FOR ADVISORY AT THIS
TIME BUT WILL HAVE TO MONITOR. OTHERWISE...AN UPPER LEVEL TROUGH
SPLITTING AND HEADING SOUTH OF THE REGION SHOULD BRING A RETURN TO
A NORTHERLY WIND PATTERN TOWARDS THE MIDDLE OF NEXT WEEK WITH
SMALL CRAFT ADVISORY LEVEL WIND GUSTS OF 25 TO 30 KT POSSIBLE.
HIGH PRESSURE THEN MAY SHIFT MORE SQUARELY OVER THE NORTHEAST
PACIFIC LATE IN THE WEEK AND FOCUS NORTHERLY WINDS ACROSS THE
CENTRAL OREGON WATERS. EVEN THOUGH SEAS LOOK TO REMAIN UNDER 10 FT
INDEFINITELY...SEAS WILL LIKELY BECOME FRESH SWELL/WIND DOMINATED
DURING THE MIDDLE TO LATTER HALF OF THE WORK WEEK SO IT STILL
LOOKS A BIT CHOPPY AND ROUGH FOR SMALLER BOATS. BOWEN/MH

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...NONE.

&&

$$

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 011654
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
950 AM PDT SUN MAY  1 2016

.SYNOPSIS...A STRONG RIDGE OF HIGH PRESSURE RESIDES OVER WESTERN
CANADA AND A BROAD UPPER LOW OVER THE INTERMOUNTAIN REGION AND
SOUTHWESTERN U.S. THIS PATTERN WILL USHER IN WARM OFFSHORE FLOW
TODAY...WITH TEMPERATURES WELL ABOVE NORMAL AT INLAND LOCATIONS AND
THE COAST.  THIS PATTERN BEGINS TO BREAK DOWN MONDAY AS A PACIFIC
COLD FRONT SLOWLY APPROACHES THE COAST. THIS SHOULD COOL DOWN THE
COAST MONDAY...WITH COOLER TEMPERATURES SPREADING INLAND TUESDAY AND
WEDNESDAY. SHOWER CHANCES WILL INCREASE AS THE FRONT APPROACHES...
WITH ISOLATED THUNDERSTORMS POSSIBLE FOR MUCH OF THE FORECAST AREA
LATE MONDAY INTO TUESDAY. SHOWERS CONTINUE INTO MIDWEEK...THEN
MODELS HINT AT ANOTHER WARMING AND DRYING TREND DEVELOPING BY NEXT
WEEKEND.

&&

.SHORT TERM...SATELLITE IMAGERY SHOWS CLEAR SKIES AROUND THE REGION
THIS MORNING. THE EXCEPTION IS SOME CUMULUS DEVELOPING ALONG THE
OREGON CASCADES FROM ABOUT DETROIT SOUTHWARD. AN UNSEASONABLY STRONG
UPPER LEVEL RIDGE OF HIGH PRESSURE REMAINS OVER WESTERN CANADA AND A
BROAD UPPER LOW SITS OVER THE INTERMOUNTAIN AND SOUTHWEST US. A
THERMAL LOW WILL ALSO BUILD NORTHWARD ALONG THE COAST TODAY.
OVERALL...EXPECT VERY PLEASANT SPRING WEATHER TODAY WITH
TEMPERATURES IN THE MID 70S TO AROUND 80. THE COASTAL REGION SHOULD
ALSO SEE TEMPS NEAR 80 THIS AFTERNOON AS WE HAVE DEEP EASTERLY FLOW
OVER THE REGION.

THE THERMAL LOW ALONG THE COAST WILL PUSH OFFSHORE TONIGHT AND LIFT
NORTHWARD OFF THE COAST AS A CLOSED THERMAL LOW MONDAY. AS THE LOW
SHIFTS NORTHWARD...MODELS SHOW A SOUTHERLY WIND REVERSAL SPREADING
UP THE COAST BEHIND THE THERMAL LOW DURING THE DAY ON MONDAY. AT
THIS TIME...THERE IS VERY LITTLE STRATUS ALONG THE CA COAST...SO IT
IS HARD TO TELL JUST HOW MUCH FOG AND LOW CLOUDS WILL ACCOMPANY THE
WIND REVERSAL. WILL LOOK AT THIS MORE CLOSELY THIS AFTERNOON.
NONETHELESS...THE SWITCH TO S-SW FLOW WILL COOL THE COAST
CONSIDERABLY ON MONDAY AND TUESDAY.

BY MONDAY AFTERNOON...MODELS SHOW ENOUGH INSTABILITY AND MOISTURE
ARRIVING FOR THE THREAT OF CONVECTION. AS USUAL...THE BEST CHANCE
FOR THUNDER WILL BE ALONG THE CASCADES WHERE THE ELEVATED HEAT SOURCE
CAN BREAK A WEAK CAP. THERE IS ALSO SOME INSTABILTY AND A FAIR AMOUNT
OF CAPE IN THE VALLEY MON COUPLED WITH S-SE STEERING FLOW...SO THERE
IS ALSO A THREAT OF TSTORMS IN THE VALLEY MONDAY EVENING AND MONDAY
NIGHT.

TUESDAY WILL BE A TRANSITION DAY BACK TO MORE SEASONAL EARLY MAY
WEATHER AS ONSHORE FLOW RETURNS. THIS SHOULD RESULT IN A 10-15 DEGREE
COOLDOWN INLAND TUESDAY. INCREASING LOW-LEVEL MOISTURE AND THE
APPROACH OF THE FRONT WILL LIKELY KICK OFF MORE SHOWER ACTIVITY
TUESDAY. TW

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
TUESDAY NIGHT THROUGH SATURDAY. BROAD UPPER TROUGH REMAINS OVER THE
EASTERN PACIFIC JUST OFF THE CALIFORNIA COAST...PROVIDING FOR SOUTH
TO SOUTHWEST FLOW ALOFT OVER THE REGION. THIS WILL KEEP SHOWER
CHANCES IN PLACE THROUGH THURSDAY. THUNDER CHANCES TUESDAY NIGHT AND
WEDNESDAY AFTERNOON/EVENING WILL BE GREATEST IN THE CASCADES AND
FOOTHILLS...BUT LATEST MODELS SUGGEST ENOUGH INSTABILITY TO KEEP A
SLIGHT CHANCE MENTION FOR THE WILLAMETTE VALLEY. MAY NOT BE ENOUGH OF
A TRIGGER TO TAP INTO THIS...BUT GIVEN THE POTENTIAL IN THE MODEL
SOUNDINGS FEEL A SLIGHT CHANCE REMAINS WARRANTED. EXPECT SOME WARMING
ON FRIDAY AND SATURDAY...WITH PERHAPS SOME DRY CONDITIONS... AS THE
UPPER LOW MIGRATES EASTWARD INTO THE GREAT BASIN AND HIGH PRESSURE
BUILDING INTO THE GULF OF ALASKA AS REX BLOCK DEVELOPS OVER THE
REGION. HOWEVER...MAINTAINED THE FORECAST ALONG THE LINES SUGGESTED
BY A BLEND OF MODELS AS THE ECMWF CONTINUES TO REMAIN WITH A MORE WET
SOLUTION AND SOME SPREAD IN THE GFS ENSEMBLE MEMBERS.

&&

.AVIATION...INCREASING OFFSHORE FLOW WILL BRING VFR CONDITIONS TO
ALL TAF SITES THROUGH 12Z MONDAY. HOWEVER THERE IS INCREASING
CHANCES FOR IFR STRATUS TO REACH KONP CLOSE TO 12Z MON BUT WILL
NOT INCLUDE IN FORECAST AT THIS TIME. 5SM VISIBILITY AT KAST
STILL SEEMS SUSPICIOUS BASED ON WEB CAMERAS SO KEPT THEM VFR EVEN
THOUGH THE OBSERVATIONS SUGGEST OTHERWISE.

KPDX AND APPROACHES...INCREASING OFFSHORE FLOW WILL BRING VFR
CONDITIONS THROUGH 12Z MONDAY. EASTERLY WINDS WILL INCREASE MIDDAY
WITH GUSTS TO 25 KT OVER EASTERN APPROACHES THROUGH EARLY
EVENING. BOWEN/MH

&&

.MARINE...A THERMAL TROUGH OVER THE SOUTH OREGON COAST WILL WEAKEN
THIS MORNING WITH WINDS CONTINUING TO EASE OVER THE WATERS. WINDS
HAVE DROPPED BELOW 20 KT AND DOMINANT PERIODS HAVE REBOUNDED AS A
RESULT...BACK UP TO 12 TO 14 SECONDS. WILL LET THE SMALL CRAFT
ADVISORY FOR SEAS EXPIRE AS SEAS ARE NO LONGER SQUARE AND SHOULD
REMAIN 6 TO 8 FT TODAY. WILL ALSO CANCEL THE ADVISORY FOR WINDS.
WILL SEE SOME POTENTIAL FOR GUSTS TO 25 KT OFF COASTAL GAPS THIS
AFTERNOON AND EVENING DUE TO OFFSHORE FLOW...BUT WILL LIKELY BE
TOO LOCALIZED FOR A SMALL CRAFT ADVISORY. NONETHELESS...MARINERS
SHOULD BE AWARE OF THESE INCREASED WINDS NEAR COASTAL GAPS.

THE THERMAL TROUGH SHIFTS OFF THE COASTLINE AND OVER THE WATERS
TODAY...SETTING UP FOR A SOUTHERLY WIND REVERSAL TO PUSH UP THE
COAST TONIGHT INTO MONDAY WHICH COULD BRIEFLY BRING A PERIOD OF
20 TO 25 KT WIND GUSTS. NOT A CLEAR SIGNAL FOR ADVISORY AT THIS
TIME BUT WILL HAVE TO MONITOR. OTHERWISE...AN UPPER LEVEL TROUGH
SPLITTING AND HEADING SOUTH OF THE REGION SHOULD BRING A RETURN TO
A NORTHERLY WIND PATTERN TOWARDS THE MIDDLE OF NEXT WEEK WITH
SMALL CRAFT ADVISORY LEVEL WIND GUSTS OF 25 TO 30 KT POSSIBLE.
HIGH PRESSURE THEN MAY SHIFT MORE SQUARELY OVER THE NORTHEAST
PACIFIC LATE IN THE WEEK AND FOCUS NORTHERLY WINDS ACROSS THE
CENTRAL OREGON WATERS. EVEN THOUGH SEAS LOOK TO REMAIN UNDER 10 FT
INDEFINITELY...SEAS WILL LIKELY BECOME FRESH SWELL/WIND DOMINATED
DURING THE MIDDLE TO LATTER HALF OF THE WORK WEEK SO IT STILL
LOOKS A BIT CHOPPY AND ROUGH FOR SMALLER BOATS. BOWEN/MH

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...NONE.

&&

$$

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 011049
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
348 AM PDT SUN MAY  1 2016

.SYNOPSIS...THE MONTH OF MAY IS STARTING OFF WITH YET ANOTHER ROUND
OF UNSEASONABLY WARM WEATHER FOR SOUTHWEST WASHINGTON AND NORTHWEST
OREGON. A REX BLOCK PATTERN IS SETTING UP OVER WESTERN NORTH
AMERICA...WITH STRONG UPPER RIDGING OVER WESTERN CANADA AND A BROAD
UPPER LOW OVER THE SOUTHWESTERN UNITED STATES. THIS WILL USHER IN
WARM OFFSHORE FLOW TODAY...WITH TEMPERATURES WELL ABOVE NORMAL ALL
THE WAY TO THE COAST. THIS PATTERN BEGINS TO BREAK DOWN A BIT MONDAY
AS A PACIFIC COLD FRONT SLOWLY APPROACHES THE COAST. THIS SHOULD COOL
DOWN THE COAST MONDAY...WITH COOLER TEMPERATURES SPREADING INLAND
TUESDAY AND WEDNESDAY. SHOWER CHANCES WILL INCREASE AS THE FRONT
APPROACHES...WITH ISOLATED THUNDERSTORMS POSSIBLE FOR MUCH OF THE
FORECAST AREA LATE MONDAY INTO TUESDAY. SHOWERS CONTINUE INTO
MIDWEEK...THEN MODELS HINT AT ANOTHER WARMING AND DRYING TREND
DEVELOPING BY NEXT WEEKEND.

&&

.SHORT TERM...AFTER THE WARMEST APRIL ON RECORD SINCE THE 1920S OR
1930S...MAY BEGINS WITH ANOTHER ROUND OF UNSEASONABLY WARM WEATHER
FOR SOUTHWEST WASHINGTON AND NORTHWEST OREGON. A REX BLOCK PATTERN IS
DEVELOPING AS UNSEASONABLY STRONG UPPER RIDGING TAKES RESIDENCE OVER
WESTERN CANADA AND A BROAD UPPER LOW SITS OVER THE SOUTHWESTERN
UNITED STATES. OFFSHORE PRESSURE GRADIENTS APPEAR TO BE HOLDING OFF
UNTIL A WEAK AND DRY UPPER DISTURBANCE RETROGRADES EAST TO WEST
ACROSS OREGON. THE VORTMAX ASSOCIATED WITH THIS DISTURBANCE IS TOUGH
TO PICK OUT ON WATER VAPOR IMAGERY DUE TO HOW DRY THE AIR MASS IS...
BUT IT PRESENTLY APPEARS TO BE OVER BAKER AND MALHEUR COUNTIES IN
SOUTHEAST OREGON. EXPECT AN UPTICK IN EAST WINDS TODAY ONCE THIS
VORTMAX MOVES THROUGH LATER THIS MORNING. THE AFTERNOON SHOULD HAVE A
BIT OF A WARM BREEZE FOR MOST OF THE CWA...THE 06Z NAM REMAINS
CONSISTENT WITH PREVIOUS RUNS IN BRINGING 25-35 KT OF EASTERLY FLOW
AT 850 MB ALONG WITH GOOD MIXING. EXPOSED AREAS MAY SEE SOME 30-40
MPH GUSTS...BUT MOST OF THE DISTRICT SHOULD SEE GUSTS IN THE 20-30
MPH RANGE THIS AFTERNOON. THE EAST WINDS WILL BRING A QUICK RISE IN
TEMPS ONCE THEY BEGIN. WITH 850 MB TEMPS RISING TO +11 DEG C...HIGHS
TODAY SHOULD BE IN THE MID 70S TO LOWER 80S TODAY ALL THE WAY TO THE
COAST.

EAST WINDS APPEAR TO BECOME A BIT MORE CONSTRICTED THROUGH THE GORGE
TONIGHT AND EARLY MONDAY AS THE SYNOPTICALLY DRIVEN EASTERLY FLOW
ALOFT BREAKS DOWN AND VEERS MORE TO THE SOUTH...LEAVING SURFACE
PRESSURE GRADIENTS AS THE ONLY DRIVER FOR THE EAST WINDS. THIS SHOULD
ALLOW THERMAL LOW PRESSURE...INITIALLY PUSHED OFFSHORE BY TODAYS
OFFSHORE FLOW...TO LIFT NORTHWARD OFF THE COAST AS A CLOSED THERMAL
LOW MONDAY. IN TURN...MODELS SHOW A SIGNIFICANT SOUTHERLY WIND
REVERSAL SPREADING UP THE COAST BEHIND THE THERMAL LOW AS MONDAY
PROGRESSES. SINCE THERE IS PRESENTLY VERY LITTLE STRATUS ALONG THE
CALIFORNIA COAST...IT IS TOUGH TO TELL JUST HOW MUCH IN THE WAY OF
FOG AND LOW CLOUDS WILL COME WITH THE WIND REVERSAL. CLOUD COVER OR
NOT...THE SWITCH BACK TO S-SW FLOW WILL PROBABLY COOL THE COAST
CONSIDERABLY ON MONDAY. 500 MB HEIGHTS WILL NOT BE ALL THAT HIGH
ALONG THE COAST MONDAY...AT LEAST NOT WHEN COMPARED TO THE PAST
COUPLE WARM SPELLS. MODEL AVERAGE SEEMS TO BE SOMEWHERE NEAR 570 DAM.
THE LOWER HEIGHTS MAY ALLOW THE MARINE LAYER TO DEEPEN ENOUGH TO COOL
DOWN EUGENE ON MONDAY AS LOW-LEVEL FLOW TURNS SOUTHWESTERLY...OR
MAYBE NOT. MOS GUIDANCE SEEMS FAIRLY INSISTENT ON KEEPING EUGENE
UNSEASONABLY WARM...SO WE LEFT TEMPS NEAR 80 DEGREES AT EUGENE
MONDAY. CONFIDENCE IS HIGHER FOR AREAS SALEM NORTHWARD THAT MONDAY
WILL STAY IN THE 80S FOR THE INLAND VALLEYS...AS IT APPEARS DOUBTFUL
THE MARINE LAYER WILL HAVE A SUBSTANTIAL IMPACT THAT FAR NORTH BY MON
AFTERNOON.

BY MONDAY AFTERNOON...MODELS SHOW ENOUGH INSTABILITY AND MOISTURE
ARRIVING TO CONSIDER CONVECTION. AS USUAL...THE BEST CHANCE FOR
THUNDER WILL BE ALONG THE CASCADES...WHERE ODDS ARE BEST THAT
SURFACE-BASED CONVECTION CAN BREAK A WEAK CAP DUE TO THE ELEVATED
HEAT SOURCE. MODEL MIXED-LAYER CAPE IS NOT QUITE AS IMPRESSIVE ON THE
NAM AS THE MODEL WAS SHOWING LAST NIGHT...BUT 500-1000 J/KG IS STILL
IMPRESSIVE FOR OUR AREA. NOCTURNAL INVERSIONS WILL PROBABLY RESULT IN
A BIT OF A CAP FOR THE WILLAMETTE VALLEY...WITH 100-200 J/KG OF CIN
PER THE 06Z NAM. THIS MAY BE DIFFICULT TO OVERCOME...SO LOWLANDS MAY
HAVE TO RELY ON CONVECTION STARTING IN CASCADES OR COAST RANGE THEN
DRIFTING OVER THE COAST OR INLAND VALLEYS VIA S-SE FLOW ALOFT. ALSO
NOTABLE IN MODEL SOUNDINGS IS HOW DRY THE AIR MASS REMAINS MON
AFTERNOON BELOW 700 MB...00Z GFS SHOWS PORTLAND NEARLY MIXING DOWN
DRY ADIABATICALLY ALL THE WAY FROM 700 MB. SHOULD THERE BE ANY
ORGANIZATION TO CONVECTION MONDAY...THIS COULD ASSIST IN PRODUCING
SOME STRONG DOWNDRAFTS AND OUTFLOW. THE POTENTIAL FOR ELEVATED
CONVECTION IS NOT ZERO MONDAY NIGHT/TUE MORNING...BUT ALSO DOES NOT
LOOK QUITE AS GOOD AS IT DID 24 HOURS AGO WITH LATEST RUNS ONLY
SHOWING WEAK...THIN CAPE ALOFT OR A NEUTRALLY STABLE AIR MASS. LATEST
RUNS ARE SLOWING THE APPROACH OF THE PACIFIC COLD FRONT
SLIGHTLY...WHICH SEEMS REASONABLE GIVEN THE BLOCKING PATTERN. THIS
WOULD LIKELY KEEP WARMER/DRIER AIR ALOFT A LITTLE LONGER AND MAKE IT
MORE DIFFICULT FOR ELEVATED CONVECTION TO DEVELOP. REGARDLESS...
WHETHER IT BE FROM REMNANTS OF SFC-BASED CONVECTION IN THE EVENING OR
ELEVATED CONVECTION OVERNIGHT...FELT IT WOULD BE PRUDENT TO CARRY A
SLIGHT CHANCE OF THUNDER OVERNIGHT MON NIGHT THROUGHOUT THE CWA.

TUESDAY WILL BE A TRANSITION DAY BACK TO MORE SEASONAL EARLY MAY
WEATHER AS ONSHORE FLOW RETURNS. THIS SHOULD RESULT IN A 10-15 DEGREE
COOLDOWN INLAND TUESDAY. INCREASING LOW-LEVEL MOISTURE AND THE
APPROACH OF THE FRONT WILL LIKELY KICK OFF MORE SHOWER ACTIVITY
TUESDAY...THOUGH MODEL SOUNDINGS CONTINUE TO LIMIT THE POTENTIAL FOR
DEEP CONVECTION WEST OF THE CASCADES. WILL HOLD ON TO THE SLIGHT
CHANCE THUNDER TUESDAY COAST RANGE EASTWARD...BUT THE BEST CHANCE
APPEARS TO BE ALONG THE CASCADES AS LOW LEVELS BECOME INCREASINGLY
STABILIZED BY THE MARINE LAYER.

ANOTHER CLIMATE NOTE THIS MORNING...SINCE PORTLAND AIRPORT RECORDS
ONLY GO BACK TO 1940...PDX SHATTERED THEIR RECORD FOR THE ALL-TIME
WARMEST APRIL ON RECORD WITH AN AVERAGE TEMPERATURE OF 57.8 DEGREES
FOR THE MONTH. THIS IS 5.7 DEGREES ABOVE NORMAL AND 1.5 DEGREES
WARMER THAN THE PREVIOUS RECORD OF 56.3 DEGREES SET IN 2004. SITES
WITH LONGER PERIODS OF RECORD DID NOT BREAK THE ALL-TIME APRIL
RECORD...IT APPEARS 1926 AND 1934 ALSO HAD EXTREMELY WARM APRIL
TEMPERATURES. WILL TRY TO GET A PUBLIC INFORMATION STATEMENT OR
RECORD EVENT REPORT OUT WITH DETAILS LATER THIS MORNING.  WEAGLE

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
TUESDAY NIGHT THROUGH SATURDAY. BROAD UPPER TROUGH REMAINS OVER THE
EASTERN PACIFIC JUST OFF THE CALIFORNIA COAST...PROVIDING FOR SOUTH
TO SOUTHWEST FLOW ALOFT OVER THE REGION. THIS WILL KEEP SHOWER
CHANCES IN PLACE THROUGH THURSDAY. THUNDER CHANCES TUESDAY NIGHT AND
WEDNESDAY AFTERNOON/EVENING WILL BE GREATEST IN THE CASCADES AND
FOOTHILLS...BUT LATEST MODELS SUGGEST ENOUGH INSTABILITY TO KEEP A
SLIGHT CHANCE MENTION FOR THE WILLAMETTE VALLEY. MAY NOT BE ENOUGH OF
A TRIGGER TO TAP INTO THIS...BUT GIVEN THE POTENTIAL IN THE MODEL
SOUNDINGS FEEL A SLIGHT CHANCE REMAINS WARRANTED. EXPECT SOME WARMING
ON FRIDAY AND SATURDAY...WITH PERHAPS SOME DRY CONDITIONS... AS THE
UPPER LOW MIGRATES EASTWARD INTO THE GREAT BASIN AND HIGH PRESSURE
BUILDING INTO THE GULF OF ALASKA AS REX BLOCK DEVELOPS OVER THE
REGION. HOWEVER...MAINTAINED THE FORECAST ALONG THE LINES SUGGESTED
BY A BLEND OF MODELS AS THE ECMWF CONTINUES TO REMAIN WITH A MORE WET
SOLUTION AND SOME SPREAD IN THE GFS ENSEMBLE MEMBERS.

&&

.AVIATION...INCREASING OFFSHORE FLOW WILL BRING VFR CONDITIONS TO
ALL TAF SITES THROUGH 12Z MONDAY. HOWEVER THERE IS INCREASING
CHANCES FOR IFR STRATUS MAY REACH KONP CLOSE TO 12Z MON BUT WILL
NOT INCLUDE IN FORECAST AT THIS TIME.  5SM VISIBILITY AT KAST
SEEMS SUSPICIOUS BASED ON WEB CAMERAS SO KEPT THEM VFR EVEN THOUGH
THE OBSERVATIONS SUGGEST OTHERWISE.

KPDX AND APPROACHES...INCREASING OFFSHORE FLOW WILL BRING VFR
CONDITIONS THROUGH 12Z MONDAY. EASTERLY WINDS WILL INCREASE MIDDAY
WITH GUSTS TO 20 KT OVER EASTERN APPROACHES THROUGH EARLY
EVENING. /MH

&&

.MARINE...A THERMAL TROUGH OVER THE SOUTH OREGON COAST WILL WEAKEN
THIS MORNING EASING WINDS OVER THE WATERS. CURRENTLY NORTH WINDS
ARE GUSTING 25 TO 30 KT SOUTH OF CASCADE HEAD AND WEST OF 10 NM.
06Z ASCAT PASS SHOWED THIS WELL. THE ASCAT DATA SO SHOWED WEAKER
WINDS NORTH OF CASCADE HEAD SO HAVE DROPPED THE SMALL CRAFT
ADVISORY IN THAT AREA. DOMINANT PERIODS CONTINUE AROUND 7 SECONDS
AT BUOY 46050 OFF OF NEWPORT SO WILL CONTINUE THE ADVISORY FOR
STEEP SEAS THROUGH 9 AM FOR THE WATERS SOUTH OF CASCADE HEAD.

THE THERMAL TROUGH SHIFT OFF THE COASTLINE AND OVER THE WATERS
TODAY SETTING UP FOR A SOUTHERLY WIND REVERSAL TO PUSH UP THE
COAST TONIGHT INTO MONDAY AND COULD BRIEFLY BRING A PERIOD OF 20
TO 25 KT WIND GUSTS NOT A CLEAR SIGNAL FOR ADVISORY AT THIS TIME
BUT WILL HAVE TO MONITOR. OTHERWISE...AN UPPER LEVEL TROUGH
SPLITTING AND HEADING SOUTH OF THE REGION SHOULD BRING A RETURN TO
A NORTHERLY WIND PATTERN TOWARDS THE MIDDLE OF NEXT WEEK WITH
SMALL CRAFT ADVISORY LEVEL WIND GUSTS OF 25 TO 30 KT POSSIBLE.
HIGH PRESSURE THEN MAY SHIFT MORE SQUARELY OVER THE NORTHEAST
PACIFIC LATE IN THE WEEK AND FOCUS NORTHERLY WINDS ACROSS THE
CENTRAL OREGON WATERS. EVEN THOUGH SEAS LOOK TO REMAIN UNDER 10 FT
INDEFINITELY...SEAS WILL LIKELY BECOME FRESH SWELL/WIND DOMINATED
DURING THE MIDDLE TO LATTER HALF OF THE WORK WEEK SO IT STILL
LOOKS A BIT CHOPPY AND ROUGH FOR SMALLER BOATS. /MH /NEUMAN

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 AM PDT THIS MORNING FOR
     WATERS FROM CASCADE HEAD TO FLORENCE OR FROM 10 TO 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 9 AM PDT THIS
     MORNING FOR COASTAL WATERS FROM CASCADE HEAD OR TO
     FLORENCE OR OUT 60 NM.

&&

$$

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

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





000
FXUS66 KPQR 011049
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
348 AM PDT SUN MAY  1 2016

.SYNOPSIS...THE MONTH OF MAY IS STARTING OFF WITH YET ANOTHER ROUND
OF UNSEASONABLY WARM WEATHER FOR SOUTHWEST WASHINGTON AND NORTHWEST
OREGON. A REX BLOCK PATTERN IS SETTING UP OVER WESTERN NORTH
AMERICA...WITH STRONG UPPER RIDGING OVER WESTERN CANADA AND A BROAD
UPPER LOW OVER THE SOUTHWESTERN UNITED STATES. THIS WILL USHER IN
WARM OFFSHORE FLOW TODAY...WITH TEMPERATURES WELL ABOVE NORMAL ALL
THE WAY TO THE COAST. THIS PATTERN BEGINS TO BREAK DOWN A BIT MONDAY
AS A PACIFIC COLD FRONT SLOWLY APPROACHES THE COAST. THIS SHOULD COOL
DOWN THE COAST MONDAY...WITH COOLER TEMPERATURES SPREADING INLAND
TUESDAY AND WEDNESDAY. SHOWER CHANCES WILL INCREASE AS THE FRONT
APPROACHES...WITH ISOLATED THUNDERSTORMS POSSIBLE FOR MUCH OF THE
FORECAST AREA LATE MONDAY INTO TUESDAY. SHOWERS CONTINUE INTO
MIDWEEK...THEN MODELS HINT AT ANOTHER WARMING AND DRYING TREND
DEVELOPING BY NEXT WEEKEND.

&&

.SHORT TERM...AFTER THE WARMEST APRIL ON RECORD SINCE THE 1920S OR
1930S...MAY BEGINS WITH ANOTHER ROUND OF UNSEASONABLY WARM WEATHER
FOR SOUTHWEST WASHINGTON AND NORTHWEST OREGON. A REX BLOCK PATTERN IS
DEVELOPING AS UNSEASONABLY STRONG UPPER RIDGING TAKES RESIDENCE OVER
WESTERN CANADA AND A BROAD UPPER LOW SITS OVER THE SOUTHWESTERN
UNITED STATES. OFFSHORE PRESSURE GRADIENTS APPEAR TO BE HOLDING OFF
UNTIL A WEAK AND DRY UPPER DISTURBANCE RETROGRADES EAST TO WEST
ACROSS OREGON. THE VORTMAX ASSOCIATED WITH THIS DISTURBANCE IS TOUGH
TO PICK OUT ON WATER VAPOR IMAGERY DUE TO HOW DRY THE AIR MASS IS...
BUT IT PRESENTLY APPEARS TO BE OVER BAKER AND MALHEUR COUNTIES IN
SOUTHEAST OREGON. EXPECT AN UPTICK IN EAST WINDS TODAY ONCE THIS
VORTMAX MOVES THROUGH LATER THIS MORNING. THE AFTERNOON SHOULD HAVE A
BIT OF A WARM BREEZE FOR MOST OF THE CWA...THE 06Z NAM REMAINS
CONSISTENT WITH PREVIOUS RUNS IN BRINGING 25-35 KT OF EASTERLY FLOW
AT 850 MB ALONG WITH GOOD MIXING. EXPOSED AREAS MAY SEE SOME 30-40
MPH GUSTS...BUT MOST OF THE DISTRICT SHOULD SEE GUSTS IN THE 20-30
MPH RANGE THIS AFTERNOON. THE EAST WINDS WILL BRING A QUICK RISE IN
TEMPS ONCE THEY BEGIN. WITH 850 MB TEMPS RISING TO +11 DEG C...HIGHS
TODAY SHOULD BE IN THE MID 70S TO LOWER 80S TODAY ALL THE WAY TO THE
COAST.

EAST WINDS APPEAR TO BECOME A BIT MORE CONSTRICTED THROUGH THE GORGE
TONIGHT AND EARLY MONDAY AS THE SYNOPTICALLY DRIVEN EASTERLY FLOW
ALOFT BREAKS DOWN AND VEERS MORE TO THE SOUTH...LEAVING SURFACE
PRESSURE GRADIENTS AS THE ONLY DRIVER FOR THE EAST WINDS. THIS SHOULD
ALLOW THERMAL LOW PRESSURE...INITIALLY PUSHED OFFSHORE BY TODAYS
OFFSHORE FLOW...TO LIFT NORTHWARD OFF THE COAST AS A CLOSED THERMAL
LOW MONDAY. IN TURN...MODELS SHOW A SIGNIFICANT SOUTHERLY WIND
REVERSAL SPREADING UP THE COAST BEHIND THE THERMAL LOW AS MONDAY
PROGRESSES. SINCE THERE IS PRESENTLY VERY LITTLE STRATUS ALONG THE
CALIFORNIA COAST...IT IS TOUGH TO TELL JUST HOW MUCH IN THE WAY OF
FOG AND LOW CLOUDS WILL COME WITH THE WIND REVERSAL. CLOUD COVER OR
NOT...THE SWITCH BACK TO S-SW FLOW WILL PROBABLY COOL THE COAST
CONSIDERABLY ON MONDAY. 500 MB HEIGHTS WILL NOT BE ALL THAT HIGH
ALONG THE COAST MONDAY...AT LEAST NOT WHEN COMPARED TO THE PAST
COUPLE WARM SPELLS. MODEL AVERAGE SEEMS TO BE SOMEWHERE NEAR 570 DAM.
THE LOWER HEIGHTS MAY ALLOW THE MARINE LAYER TO DEEPEN ENOUGH TO COOL
DOWN EUGENE ON MONDAY AS LOW-LEVEL FLOW TURNS SOUTHWESTERLY...OR
MAYBE NOT. MOS GUIDANCE SEEMS FAIRLY INSISTENT ON KEEPING EUGENE
UNSEASONABLY WARM...SO WE LEFT TEMPS NEAR 80 DEGREES AT EUGENE
MONDAY. CONFIDENCE IS HIGHER FOR AREAS SALEM NORTHWARD THAT MONDAY
WILL STAY IN THE 80S FOR THE INLAND VALLEYS...AS IT APPEARS DOUBTFUL
THE MARINE LAYER WILL HAVE A SUBSTANTIAL IMPACT THAT FAR NORTH BY MON
AFTERNOON.

BY MONDAY AFTERNOON...MODELS SHOW ENOUGH INSTABILITY AND MOISTURE
ARRIVING TO CONSIDER CONVECTION. AS USUAL...THE BEST CHANCE FOR
THUNDER WILL BE ALONG THE CASCADES...WHERE ODDS ARE BEST THAT
SURFACE-BASED CONVECTION CAN BREAK A WEAK CAP DUE TO THE ELEVATED
HEAT SOURCE. MODEL MIXED-LAYER CAPE IS NOT QUITE AS IMPRESSIVE ON THE
NAM AS THE MODEL WAS SHOWING LAST NIGHT...BUT 500-1000 J/KG IS STILL
IMPRESSIVE FOR OUR AREA. NOCTURNAL INVERSIONS WILL PROBABLY RESULT IN
A BIT OF A CAP FOR THE WILLAMETTE VALLEY...WITH 100-200 J/KG OF CIN
PER THE 06Z NAM. THIS MAY BE DIFFICULT TO OVERCOME...SO LOWLANDS MAY
HAVE TO RELY ON CONVECTION STARTING IN CASCADES OR COAST RANGE THEN
DRIFTING OVER THE COAST OR INLAND VALLEYS VIA S-SE FLOW ALOFT. ALSO
NOTABLE IN MODEL SOUNDINGS IS HOW DRY THE AIR MASS REMAINS MON
AFTERNOON BELOW 700 MB...00Z GFS SHOWS PORTLAND NEARLY MIXING DOWN
DRY ADIABATICALLY ALL THE WAY FROM 700 MB. SHOULD THERE BE ANY
ORGANIZATION TO CONVECTION MONDAY...THIS COULD ASSIST IN PRODUCING
SOME STRONG DOWNDRAFTS AND OUTFLOW. THE POTENTIAL FOR ELEVATED
CONVECTION IS NOT ZERO MONDAY NIGHT/TUE MORNING...BUT ALSO DOES NOT
LOOK QUITE AS GOOD AS IT DID 24 HOURS AGO WITH LATEST RUNS ONLY
SHOWING WEAK...THIN CAPE ALOFT OR A NEUTRALLY STABLE AIR MASS. LATEST
RUNS ARE SLOWING THE APPROACH OF THE PACIFIC COLD FRONT
SLIGHTLY...WHICH SEEMS REASONABLE GIVEN THE BLOCKING PATTERN. THIS
WOULD LIKELY KEEP WARMER/DRIER AIR ALOFT A LITTLE LONGER AND MAKE IT
MORE DIFFICULT FOR ELEVATED CONVECTION TO DEVELOP. REGARDLESS...
WHETHER IT BE FROM REMNANTS OF SFC-BASED CONVECTION IN THE EVENING OR
ELEVATED CONVECTION OVERNIGHT...FELT IT WOULD BE PRUDENT TO CARRY A
SLIGHT CHANCE OF THUNDER OVERNIGHT MON NIGHT THROUGHOUT THE CWA.

TUESDAY WILL BE A TRANSITION DAY BACK TO MORE SEASONAL EARLY MAY
WEATHER AS ONSHORE FLOW RETURNS. THIS SHOULD RESULT IN A 10-15 DEGREE
COOLDOWN INLAND TUESDAY. INCREASING LOW-LEVEL MOISTURE AND THE
APPROACH OF THE FRONT WILL LIKELY KICK OFF MORE SHOWER ACTIVITY
TUESDAY...THOUGH MODEL SOUNDINGS CONTINUE TO LIMIT THE POTENTIAL FOR
DEEP CONVECTION WEST OF THE CASCADES. WILL HOLD ON TO THE SLIGHT
CHANCE THUNDER TUESDAY COAST RANGE EASTWARD...BUT THE BEST CHANCE
APPEARS TO BE ALONG THE CASCADES AS LOW LEVELS BECOME INCREASINGLY
STABILIZED BY THE MARINE LAYER.

ANOTHER CLIMATE NOTE THIS MORNING...SINCE PORTLAND AIRPORT RECORDS
ONLY GO BACK TO 1940...PDX SHATTERED THEIR RECORD FOR THE ALL-TIME
WARMEST APRIL ON RECORD WITH AN AVERAGE TEMPERATURE OF 57.8 DEGREES
FOR THE MONTH. THIS IS 5.7 DEGREES ABOVE NORMAL AND 1.5 DEGREES
WARMER THAN THE PREVIOUS RECORD OF 56.3 DEGREES SET IN 2004. SITES
WITH LONGER PERIODS OF RECORD DID NOT BREAK THE ALL-TIME APRIL
RECORD...IT APPEARS 1926 AND 1934 ALSO HAD EXTREMELY WARM APRIL
TEMPERATURES. WILL TRY TO GET A PUBLIC INFORMATION STATEMENT OR
RECORD EVENT REPORT OUT WITH DETAILS LATER THIS MORNING.  WEAGLE

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
TUESDAY NIGHT THROUGH SATURDAY. BROAD UPPER TROUGH REMAINS OVER THE
EASTERN PACIFIC JUST OFF THE CALIFORNIA COAST...PROVIDING FOR SOUTH
TO SOUTHWEST FLOW ALOFT OVER THE REGION. THIS WILL KEEP SHOWER
CHANCES IN PLACE THROUGH THURSDAY. THUNDER CHANCES TUESDAY NIGHT AND
WEDNESDAY AFTERNOON/EVENING WILL BE GREATEST IN THE CASCADES AND
FOOTHILLS...BUT LATEST MODELS SUGGEST ENOUGH INSTABILITY TO KEEP A
SLIGHT CHANCE MENTION FOR THE WILLAMETTE VALLEY. MAY NOT BE ENOUGH OF
A TRIGGER TO TAP INTO THIS...BUT GIVEN THE POTENTIAL IN THE MODEL
SOUNDINGS FEEL A SLIGHT CHANCE REMAINS WARRANTED. EXPECT SOME WARMING
ON FRIDAY AND SATURDAY...WITH PERHAPS SOME DRY CONDITIONS... AS THE
UPPER LOW MIGRATES EASTWARD INTO THE GREAT BASIN AND HIGH PRESSURE
BUILDING INTO THE GULF OF ALASKA AS REX BLOCK DEVELOPS OVER THE
REGION. HOWEVER...MAINTAINED THE FORECAST ALONG THE LINES SUGGESTED
BY A BLEND OF MODELS AS THE ECMWF CONTINUES TO REMAIN WITH A MORE WET
SOLUTION AND SOME SPREAD IN THE GFS ENSEMBLE MEMBERS.

&&

.AVIATION...INCREASING OFFSHORE FLOW WILL BRING VFR CONDITIONS TO
ALL TAF SITES THROUGH 12Z MONDAY. HOWEVER THERE IS INCREASING
CHANCES FOR IFR STRATUS MAY REACH KONP CLOSE TO 12Z MON BUT WILL
NOT INCLUDE IN FORECAST AT THIS TIME.  5SM VISIBILITY AT KAST
SEEMS SUSPICIOUS BASED ON WEB CAMERAS SO KEPT THEM VFR EVEN THOUGH
THE OBSERVATIONS SUGGEST OTHERWISE.

KPDX AND APPROACHES...INCREASING OFFSHORE FLOW WILL BRING VFR
CONDITIONS THROUGH 12Z MONDAY. EASTERLY WINDS WILL INCREASE MIDDAY
WITH GUSTS TO 20 KT OVER EASTERN APPROACHES THROUGH EARLY
EVENING. /MH

&&

.MARINE...A THERMAL TROUGH OVER THE SOUTH OREGON COAST WILL WEAKEN
THIS MORNING EASING WINDS OVER THE WATERS. CURRENTLY NORTH WINDS
ARE GUSTING 25 TO 30 KT SOUTH OF CASCADE HEAD AND WEST OF 10 NM.
06Z ASCAT PASS SHOWED THIS WELL. THE ASCAT DATA SO SHOWED WEAKER
WINDS NORTH OF CASCADE HEAD SO HAVE DROPPED THE SMALL CRAFT
ADVISORY IN THAT AREA. DOMINANT PERIODS CONTINUE AROUND 7 SECONDS
AT BUOY 46050 OFF OF NEWPORT SO WILL CONTINUE THE ADVISORY FOR
STEEP SEAS THROUGH 9 AM FOR THE WATERS SOUTH OF CASCADE HEAD.

THE THERMAL TROUGH SHIFT OFF THE COASTLINE AND OVER THE WATERS
TODAY SETTING UP FOR A SOUTHERLY WIND REVERSAL TO PUSH UP THE
COAST TONIGHT INTO MONDAY AND COULD BRIEFLY BRING A PERIOD OF 20
TO 25 KT WIND GUSTS NOT A CLEAR SIGNAL FOR ADVISORY AT THIS TIME
BUT WILL HAVE TO MONITOR. OTHERWISE...AN UPPER LEVEL TROUGH
SPLITTING AND HEADING SOUTH OF THE REGION SHOULD BRING A RETURN TO
A NORTHERLY WIND PATTERN TOWARDS THE MIDDLE OF NEXT WEEK WITH
SMALL CRAFT ADVISORY LEVEL WIND GUSTS OF 25 TO 30 KT POSSIBLE.
HIGH PRESSURE THEN MAY SHIFT MORE SQUARELY OVER THE NORTHEAST
PACIFIC LATE IN THE WEEK AND FOCUS NORTHERLY WINDS ACROSS THE
CENTRAL OREGON WATERS. EVEN THOUGH SEAS LOOK TO REMAIN UNDER 10 FT
INDEFINITELY...SEAS WILL LIKELY BECOME FRESH SWELL/WIND DOMINATED
DURING THE MIDDLE TO LATTER HALF OF THE WORK WEEK SO IT STILL
LOOKS A BIT CHOPPY AND ROUGH FOR SMALLER BOATS. /MH /NEUMAN

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 AM PDT THIS MORNING FOR
     WATERS FROM CASCADE HEAD TO FLORENCE OR FROM 10 TO 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 9 AM PDT THIS
     MORNING FOR COASTAL WATERS FROM CASCADE HEAD OR TO
     FLORENCE OR OUT 60 NM.

&&

$$

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

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





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