Area Forecast Discussion
Issued by NWS Portland, OR

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FXUS66 KPQR 030949
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND
249 AM PDT WED JUN  3 2015

.SYNOPSIS...AN UPPER LEVEL LOW PRESSURE AREA WILL REMAIN OVER THE
PACIFIC NORTHWEST TODAY FOR CONTINUED RATHER CLOUDY CONDITIONS AND A
FEW SHOWERS. THE UPPER LOW WILL MOVE EAST AND WEAKEN TONIGHT AND
THURSDAY AS THE NEXT UPSTREAM SYSTEM DIVES SOUTH OFF THE COAST AND
DEVELOPS INTO A CLOSED LOW OVER CALIFORNIA ON THURSDAY...REMAINING
MOSTLY TO OUR SOUTH THROUGH THE WEEKEND. THIS WILL ALLOW A STRONG
UPPER LEVEL RIDGE TO MOVE INTO THE PACIFIC NORTHWEST FROM THE WEST
THAT WILL CAUSE A TRANSITION TO MUCH MUCH WARMER AND DRIER WEATHER
FOR LATE IN THE WEEK AND THIS WEEKEND. THE WARMEST WEATHER OF THE
YEAR SO FAR IS LIKELY THIS WEEKEND...POSSIBLY CONTINUING INTO MONDAY.
WE MAY START TO COOL THINGS OFF AS WE GET INTO THE MIDDLE OF NEXT
WEEK.
&&

.SHORT TERM...THE MODELS CONTINUE TO INDICATE THAT AN UPPER LOW WILL
CONTINUE TO REMAIN OVER WASHINGTON TODAY AS IT ALSO AFFECTS A GOOD
PART OF NORTHERN OREGON. INFRARED SATELLITE IMAGERY SHOWS WRAPAROUND
CLOUDINESS ON THE BACK SIDE OF THE LOW OFF THE WASHINGTON COAST
CONTINUING TO SPREAD INTO NORTHWEST OREGON WITH A FEW SHOWERS. THE
FORCING TODAY LOOKS A BIT WEAKER THOUGH AND THERE IS STILL A WEAK
AREA OF VORTICITY IN THE CLOUDS ALONG THE COAST THAT WILL SLOWLY MOVE
INLAND TODAY. SO EXPECT FAIRLY CLOUDY CONDITIONS TO CONTINUE
TODAY...POSSIBLY A FEW BREAKS IN THE CLOUDS IN THE SOUTH...WITH A FEW
SHOWERS MAINLY ACROSS THE NORTH AND OVER THE HIGHER TERRAIN. THE
SHOWERS SHOULD BE LESS NUMEROUS TODAY AS WELL. TEMPS WILL REMAIN
COOL...BUT MAY RISE A FEW DEGREES INTO THE MID 60S OR SO.

THE NEXT UPSTREAM SYSTEM CURRENTLY APPROACHING 130W CONTINUES TO BE
FORECAST TO DIG SOUTH OFF THE COAST AND MOVE INTO CALIFORNIA AS AN
UPPER LOW LATER TONIGHT AND THURSDAY. IN ITS WAKE AN UPPER RIDGE WILL
START TO NOSE INTO THE PACIFIC NORTHWEST THAT SHOULD BRING SOME
CLEARING THURSDAY AFTERNOON AFTER AREAS OF MORNING CLOUDS. 850 MB
TEMPS SUGGEST HIGHS INLAND ON THURSDAY WILL PUSH UP INTO THE MID
70S...A BIT ABOVE SEASONAL NORMALS.

THE UPPER RIDGE WILL CONTINUE BUILDING INTO THE PACIFIC NORTHWEST
THURSDAY NIGHT AND FRIDAY...WITH 500 MB HEIGHTS RISING TO NEARLY 580
DM...APPROACHING SUMMERTIME VALUES. AFTER BRIEF MORNING CLOUDS...
LOOK FOR ABUNDANT SUNSHINE ON FRIDAY WITH TEMPS RISING TO BETWEEN 80
AND 85 DEGREES INLAND IN THE AFTERNOON. TOLLESON

.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY...THE STRONG UPPER RIDGE
WILL BE OVER THE PACIFIC NORTHWEST IN FORCE OVER THE WEEKEND...WITH
500 MB HEIGHTS IN THE 580S AND 850 MB TEMPS EXCEEDING 20 DEGREES C.
THUS IT LOOKS AS THOUGH TEMPS SHOULD REACH 90 OVER THE WEEKEND...
POSSIBLY THE MID 90S ON SUNDAY. THE UPPER LOW OVER CALIFORNIA IS
FORECAST TO STAY SOUTH...BUT WE MAY NEED TO WATCH WHETHER ANY
THUNDERSTORM MOISTURE SPREADS BACK NORTH CLOSE TO OUR LANE COUNTY
CASCADES. WITH TROPICAL ACTIVITY BEGINNING TO PICK UP IN THE PACIFIC
BASIN...MODEL CONSISTENCY IS NOT THE BEST WITH HOW LONG THE HOT SPELL
WILL LAST INTO NEXT WEEK AND FOR WHEN THE NEXT TROUGH WILL APPROACH
AND COOL US DOWN. CURRENT TRENDS SUGGEST THAT MONDAY WILL STAY QUITE
WARM ESPECIALLY INLAND...AND HAVE TRENDED THE FORECAST THAT WAY. WE
MAY FINALLY GET SOME MORE ONSHORE FLOW AROUND THE MIDDLE OF NEXT
WEEK...BUT THE TIMING IS UNCERTAIN AS THE ECMWF AND GFS MODELS START
TO DEVIATE THEN. TOLLESON
&&

.AVIATION...A WEAK UPPER TROUGH WILL CONTINUE OVER THE REGION TODAY.
AN EMBEDDED UPPER LOW OVER SW WASHINGTON DEVELOPING SOME LIGHT
SHOWERS ALONG THE COASTAL AREAS. FLIGHT CONDITIONS ARE GENERALLY MVFR
TO IFR BUT THERE HAVE BEEN OCCASIONAL BREAKS TO VFR. EXPECT THE LOWER
CONDITIONS TO BE THE MAIN FLIGHT CATEGORY TODAY WITH THE POSSIBILITY
OF SOME VFR IN THE MID AFTERNOON AND EARLY EVENING.  INLAND...MOST
INDICATIONS SHOW A GOOD CHANCE MVFR CIGS AROUND 2000-2500 FEET WILL
DEVELOP THIS MORNING. HOWEVER THE GFS AND NAM BUFR SOUNDINGS HAVE
DIFFERENT STABILITY WHICH DECREASES FORECAST CONFIDENCE. CIGS
EXPECTED TO IMPROVE TO VFR AROUND 17-18Z WEDNESDAY AS LOW-LEVEL WINDS
START TO TURN MORE NORTHWESTERLY AND START TO RAMP UP A BIT IN THE
AFTERNOON.

KPDX AND APPROACHES...GENERALLY EXPECT OCCASIONAL CIGS AROUND
2000-2500 FEET IN THE AREA THROUGH ABOUT 18Z WED. 07Z WED AMDAR DATA
FROM A FLIGHT OUT OF KPDX SHOW A STABLE LAYER JUST AROUND 2000 FEET
SO THIS MAY BE THE LEVEL CIGS DEVELOP. THERE IS ALSO A LAYER AROUND
700 FEET THAT HAS DEVELOPED OVER KVUO. THIS COULD ALSO TEMPORARILY
AFFECT KPDX EARLY THIS MORNING. VFR EXPECTED AROUND 17-18Z. VFR
CONDITIONS EXPECTED TO CONTINUE THROUGH THE AFTERNOON. /MH
&&

.MARINE...HIGH PRESSURE IS BUILDING OVER THE WATERS OVERNIGHT
TONIGHT...SHIFTING WINDS OVER THE WATERS TO NORTHWESTERLY. THIS HIGH
PRESSURE SYSTEM WILL CONTINUE TO BUILD AND PERSIST OVER THE WATERS
THROUGH THIS WEEKEND INTO EARLY NEXT WEEK BRINING PERSISTENT GUSTY
NORTHERLY WINDS OVER THE WATERS...WEAKENING A BIT DURING THE MORNING
HOURS AND RAMPING BACK UP DURING THE AFTERNOON AND EVENING HOURS. THE
STRONGEST WINDS ARE EXPECTED OVER THE CENTRAL OREGON WATERS... WITH
SMALL CRAFT ADVISORY GUSTS UP TO 30 KTS STARTING THURSDAY AFTERNOON
AND LIKELY PERSISTING THROUGH AT LEAST SUNDAY. THE NORTHERN WATERS
COULD STAY BELOW ADVISORY THRESHOLDS UNTIL FRIDAY AFTERNOON...WITH
GUSTS OVER THE WEEKEND LIKELY STAYING A BIT LOWER REACHING AROUND 25
KTS. THERE MAY BE PERIODS DURING THE MORNING HOURS OVER THE NORTHERN
WATERS THAT WINDS DROP BELOW CRITERIA...BUT THERE IS MUCH UNCERTAINTY
RIGHT NOW ON HOW LONG THESE PERIODS MAY LAST AND HOW LOW WINDS WILL
DROP.

SEAS EXPECTED TO STAY AROUND 3 TO 4 FT THROUGH TODAY. AS WINDS START
TO INCREASE OUT OF THE NORTH...EXPECT SEAS TO BECOME INCREASINGLY
MORE WIND WAVE DOMINATED...BUILDING TO AROUND 6 TO 8 FT BY THURSDAY
AFTERNOON. SEAS EXPECTED TO REMAIN AROUND 6 TO 8 FT THROUGH THE
WEEKEND. -MCCOY /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.



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