Area Forecast Discussion
Issued by NWS Portland, OR

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS66 KPQR 022159
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND
259 PM PDT TUE JUN 2 2015

.SYNOPSIS...UPPER LEVEL LOW PRES WILL REMAIN OVER THE REGION THROUGH
WED BEFORE MOVING EAST...KEEPING THE WEATHER COOLER AND SHOWERY.
ANOTHER UPPER LEVEL TROUGH WILL DIVE SOUTH ALONG THE COAST WED NIGHT
AND DEVELOP INTO A CLOSED LOW OVER CALIF ON THU. THIS WILL BEGIN A
TRANSITION TO WARMER AND DRIER WEATHER LATE IN THE WEEK. THE CUTOFF
LOW WILL REMAIN TO OUR SOUTH THROUGH THE WEEKEND. AT THE SAME
TIME...A STRONG UPPER LEVEL RIDGE WILL DEVELOP OVER THE NE PAC LATE
IN THE WEEK AND MOVE INTO THE PAC NW FRI AND OVER THE WEEKEND. THIS
WILL BRING A PERIOD OF VERY WARM WEATHER...LIKELY THE WARMEST TEMPS
OF THE YEAR...OVER THE WEEKEND. AN UPPER LEVEL TROUGH WILL KICK THE
RIDGE EAST AND COOL THINGS OFF A BIT SOMETIME EARLY NEXT WEEK.

&&

.SHORT TERM...TONIGHT THROUGH FRIDAY...COOL AND CLOUDY CONDITIONS
CONTINUE TODAY AS A BROAD AREA OF UPPER LEVEL LOW PRES REMAINS OVER
THE REGION. AN EMBEDDED SHORTWAVE MOVED THROUGH EARLIER TODAY...WHICH
BROUGHT DRIZZLE AND WEAK SHOWERS IN ADDITION TO STRENGTHENING THE
ONSHORE FLOW. SHOWERS HAVE BECOME A BIT MORE ORGANIZED THIS AFTERNOON
DUE TO LOW LEVEL INSTABILITY FROM DAYTIME HEATING...PARTICULARLY DOWN
OVER THE SOUTHERN WILLAMETTE VALLEY WHERE VISIBLE SATELLITE SHOWS A
FEW SUN BREAKS HAVING DEVELOPED OVER THE PAST COUPLE OF HOURS.
SHOWERS TO BECOME MORE CONFINED TO THE HIGHER TERRAIN LATER THIS
EVENING AS WE LOSE THE DAYTIME HEATING...BUT SOME SHOWER ACTIVITY
WILL CONTINUE OVERNIGHT INTO WED.

SHOWERS MAY LINGER THROUGH MUCH OF WED...BUT EXPECT COVERAGE TO
GENERALLY DECREASE DURING THE DAY AS UPPER LOW MOVES EAST THROUGH.
OTHERWISE...IT WILL GENERALLY BE ANOTHER CLOUDY AND COOLER DAY.
EXPECT WE WILL SEE A FEW MORE SUN BREAKS DEVELOP TOMORROW
AFTERNOON...WHICH SHOULD LEAD TO TEMPS INCREASING A FEW DEGREES OVER
TODAY.

ANOTHER UPPER LEVEL TROUGH WILL APPROACH THE PAC NW WED NIGHT AND
WILL DIVE SOUTHWARD AND DEVELOP INTO A CLOSED LOW OVER N CALIF ON
THU. THE LOW MAY SWING SOME MOISTURE AND WEAK INSTABILITY UP INTO THE
LANE COUNTY CASCADES THU AFTERNOON AND EVENING...SO WILL MAINTAIN A
SLIGHT CHANCE OF THUNDER IN THE FCST. OTHERWISE...EXPECT A TREND
TOWARD DRY WEATHER WITH DECREASING CLOUDS AND WARMER TEMPS TO BEGIN
THU. THERE SHOULD STILL BE A GOOD AMOUNT OF CLOUD COVER THU
MORNING...BUT EXPECT THERE WILL BE GOOD A GOOD BIT OF SUN DURING THE
AFTERNOON. INLAND HIGHS THU SHOULD BE BACK INTO THE 70S.

THE CLOSED LOW TO THE SOUTH WILL BECOME CUTOFF FROM THE UPPER LEVEL
FLOW AND STALL OUT THROUGH THE END OF THE WEEK. AT THE SAME TIME...AN
UPPER LEVEL RIDGE WILL STRENGTHEN OVER THE NE PAC. THE RIDGE WILL
BEGIN TO BUILD INTO THE PAC NW ON FRI...AND IS EXPECTED TO BRING A
SIGNIFICANT INCREASE IN TEMPS AND A DECREASE IN CLOUDS. EXPECT INLAND
HIGHS FRI TO INCREASE A GOOD 10 DEGREES OVER THU...REACHING INTO THE
LOW TO MID 80S. PYLE

.LONG TERM...A STRONG UPPER LEVEL RIDGE IS MODELED TO EXTEND FROM THE
NE PAC INTO THE PAC NW AND B.C. THIS UPCOMING WEEKEND. THIS WILL
BRING A PERIOD OF DRY AND VERY WARM WEATHER. THE MODELS HAVE BACKED
OFF JUST A BIT ON THE TEMPERATURES OVER THE WEEKEND...BUT IT STILL
APPEARS THAT TEMPERATURES OVER THE INTERIOR LOWLANDS WILL APPROACH 90
DEGREES ON BOTH SAT AND SUN...WHICH WOULD BE THE WARMEST STRETCH OF
WEATHER SO FAR THIS YEAR. TEMPS AT THE COAST ARE EXPECTED TO STAY
SIGNIFICANTLY COOLER WITH NW FLOW BRINGING MARINE AIR ONSHORE. AN
UPPER LEVEL TROUGH IS MODELED TO PUSH TOWARD THE REGION EARLY NEXT
WEEK...WHICH WILL EVENTUALLY NUDGE THE RIDGE EASTWARD. THIS WILL
USHER IN INCREASING ONSHORE FLOW AND COOLER TEMPS. THE LATEST FCST
COOLS THINGS DOWN QUITE A BIT MON...BUT IF THE TROUGH IS A LITTLE
SLOWER TO DEPART...MON COULD END UP BEING QUITE WARM AS WELL. PYLE

&&

.AVIATION..LARGELY MVFR CIGS ALONG THE COAST THIS AFTERNOON AS AN
ORGANIZED BAND OF HEAVIER SHOWERS HAS NOW PUSHED INTO THE
INTERIOR. THIS LINE OF MODERATE SHOWERS MAY BRING TEMPORARY
REDUCTIONS TO MVFR OR EVEN IFR AT TIMES THROUGH THIS
AFTERNOON...BUT OTHERWISE GRADUAL IMPROVEMENT TOWARDS LOWER
VFR/HIGH MVFR CIGS THROUGH THIS EVENING WITH CONTINUING SHOWERS.
CIGS LOWER AGAIN AFT 09Z FOR IFR/LOW MVFR AT THE COAST AND MVFR
INLAND LIKELY BECOMING WIDESPREAD WITH S-SW LOW LEVEL FLOW
TURNING MORE S OVERNIGHT. THEN EXPECT CIGS TO LIFT BACK TO VFR AFT
17Z WED WITH SHOWERS TAPERING OFF AND WINDS BECOMING INCREASINGLY
W-NW.

KPDX AND APPROACHES...GENERALLY EXPECT CIGS TO PERSIST AROUND
3000 FT THIS EVENING...THOUGH HEAVIER SHOWERS MAY BRING TEMPORARY
REDUCTIONS TO MVFR CIGS AND VSBYS THIS AFTERNOON. CIGS AGAIN
LIKELY LOWER TO AROUND 2500 FT OVERNIGHT WITH SURFACE WINDS
BECOMING S AFT 06Z THROUGH THE OVERNIGHT. WINDS WILL BECOME W-NW
WITH CIGS BECOMING VFR AFT 17Z WED.   CULLEN


&&

.MARINE...LIGHT W-SW WINDS CONTINUE OVER THE WATERS CONTINUE THIS
AFTERNOON AS THE WEAK LOW PRESSURE DISTURBANCES PUSHES THROUGH THE
WATERS. HIGH PRESSURE WILL THEN BEGIN TO BUILD OVER THE NE PAC
OVERNIGHT AND EARLY TOMORROW AND SLIDE TOWARDS THE COASTAL WATERS.
THIS HIGH PRES WILL CONTINUE TO BUILD AND PERSIST THROUGH MUCH OF
THE WEEK. THIS WILL LEAD TO PERSISTENT GUSTY NORTHERLY WINDS OVER
THE WATERS THROUGH THE SECOND HALF OF THE WEEK. WINDS WILL BE
STRONGEST DURING THE AFTERNOON AND EVENING HOURS...WITH SOME
EASING OF WINDS DURING THE MORNING. THE STRONGEST WINDS...WITH
GUSTS TO 30 KT...WILL OCCUR OVER THE CENTRAL OREGON WATERS WITH
SMALL CRAFT STRENGTH GUSTS POSSIBLE THURSDAY AFTERNOON THROUGH THE
WEEKEND. GUSTS WILL LIKELY WARRANT SMALL CRAFT ADVISORIES AT TIMES
FOR THE NORTHERN ZONES AS WELL...BUT LIKELY TOP OUT AROUND 25 KT
AND WILL POTENTIALLY EASE BELOW ADVISORY THRESHOLDS DURING THE
MORNINGS. AS WINDS INCREASE...WAVE HEIGHTS WILL BE INCREASINGLY
WIND WAVE DOMINATED AND BUILDING TO 6 TO 8 FEET BY THURSDAY AND
REMAIN ELEVATED IN THIS RANGE INTO THE WEEKEND. CULLEN

&&

.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.


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.