Area Forecast Discussion
Issued by NWS Portland, OR

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FXUS66 KPQR 012125
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
225 PM PDT FRI AUG  1 2014

.SYNOPSIS...AN UPPER LEVEL RIDGE CENTERED OVER THE ROCKIES AND GREAT
BASIN WILL REMAIN INTO THE WEEKEND...THEN FLATTEN OUT EARLY
NEXT WEEK. WEAK WEATHER DISTURBANCES WILL OCCASIONALLY MOVE ACROSS
THE PACIFIC NORTHWEST DURING THE NEXT FEW DAYS WHICH WILL KEEP A
CHANCE OF MAINLY AFTERNOON AND EVENING THUNDERSTORMS...MAINLY OVER
THE CASCADES THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK.
TEMPERATURES WILL REMAIN ABOVE NORMAL...SLOWLY APPROACHING NORMAL
LATER NEXT WEEK.
&&

.SHORT TERM...THE WEATHER DISTURBANCE THAT MOVED ACROSS THE REGION
EARLY THIS MORNING HAS MOVED TO OUR NORTH. THERE IS SOME INSTABILITY
ALOFT THIS AFTERNOON WITH THUNDERSTORMS BEGINNING TO FIRE ON THE
CASCADE CREST IN LANE COUNTY AT 2PM. EXPECT ISOLATED THUNDERSTORMS
IN THE CASCADES THROUGH THE EVENING AND PERHAPS OVERNIGHT AS ANOTHER
WEAK WEATHER DISTURBANCE MOVES NORTHWARD THROUGH LATER TONIGHT.

THE MARINE LAYER WILL INCREASE ALONG THE COAST TONIGHT WITH SOME LOW
CLOUDS MOVING INLAND ALONG THE COLUMBIA RIVER TO ABOUT THE PORTLAND
AREA BY SATURDAY MORNING.  THERE WILL ALSO BE A CHANCE OF
AFTERNOON/EVENING THUNDERSTORMS ON THE CASCADES AGAIN SATURDAY.

NOT A LOT OF CHANGE ON SUNDAY...WITH A CHANCE OF THUNDERSTORMS OVER
THE CASCADES AGAIN IN THE AFTERNOON AND EVENING. THE INLAND PUSH OF
LOW CLOUDS INTO THE COASTAL GAPS LOOKS BETTER BY SUNDAY...AND EXPECT
LOW CLOUDS WILL COVER A LARGE AREA OF AROUND PORTLAND AND VANCOUVER
TOWARD THE CASCADE FOOTHILLS FOR SEVERAL HOURS SUNDAY MORNING. TW

.LONG TERM...MODELS REMAIN IN PRETTY GOOD AGREEMENT SHOWING THE
REGION UNDER A WEAK 500 MB FLOW THROUGH MOST OF NEXT WEEK. THERE WILL
ALSO BE SOME LOW LEVEL ONSHORE FLOW AS A RESULT OF THE HIGH PRESSURE
OVER THE NE PACIFIC. OVERALL...EXPECT A DRY PATTERN WITH THE FLOW
ALOFT FAVORING A LIGHT WESTERLY WIND...AND TEMPS REMAINING A BIT
ABOVE NORMAL.
&&

.AVIATION...HIGH PRESSURE WILL LEAD TO VFR CONDITIONS ACROSS THE
INTERIOR AND INCREASING IFR CONDITIONS ALONG THE COAST THIS
AFTERNOON AND EVENING. THERE IS A CHANCE MARINE CLOUDS WILL PUSH
UP THE COLUMBIA RIVER AND IMPACT THE PORTLAND METRO AREA AROUND
DAYBREAK ON SATURDAY...BUT SHALLOW NATURE OF MOISTURE MAY LIMIT
THE UPRIVER DRIFT. SMOKE FROM WILDFIRES ACROSS SOUTHWEST OREGON
WILL CONTINUE TO IMPACT THE SOUTHERN AND EASTERN PORTIONS OF THE
FORECAST AREA...BUT SIGNIFICANT REDUCTIONS TO VISIBILITY ARE NOT
ANTICIPATED AT THIS POINT. THERE IS ALSO A SLIGHT CHANCE
THUNDERSTORMS WILL DEVELOP ONCE AGAIN OVERNIGHT AND POSSIBLY
IMPACT NORTHEASTERN TAF SITES...BUT CONFIDENCE IS VERY LOW IN
THIS SCENARIO PANNING OUT.

KPDX AND APPROACHES...SURFACE HIGH PRESSURE WILL GENERALLY PRODUCE
VFR CONDITIONS THROUGH 18Z SATURDAY. HOWEVER...THERE IS A CHANCE
HIGH END IFR TO LOW END MVFR CONDITIONS WILL SPREAD UP THE
COLUMBIA RIVER AND IMPACT THE TERMINAL PRIMARILY BETWEEN 13Z AND
18Z SATURDAY. THERE IS A 10 PERCENT CHANCE ELEVATED THUNDERSTORMS
WILL DEVELOP AGAIN TONIGHT...AND IMPACT THE TERMINAL BETWEEN 06Z
AND 12Z SATURDAY. /NEUMAN

&&

.MARINE...ONLY SUBTLE DAY TO DAY VARIATIONS EXPECTED IN THE
WEATHER PATTERN THROUGH THE WEEKEND AS HIGH PRESSURE REMAINS OVER
NORTHEAST PACIFIC. THIS WILL MAINTAIN A TYPICAL SUMMERTIME
PATTERN OF NORTHERLY WINDS...GENERALLY INCREASING EACH AFTERNOON
THROUGH AROUND MIDNIGHT.

HIGH PRESSURE SAGGING SOUTHWARD TODAY...AND LINGERING SATURDAY IN
A SIMILAR POSITION WILL LIKELY KEEP SMALL CRAFT ADVISORY LEVEL
WIND GUSTS OF 25 KT FROM MATERIALIZING ACROSS ALL THE WATERS EVEN
THOUGH MODEL GUIDANCE SUGGESTS OTHERWISE. HOWEVER...WOULD STILL
NOT BE SURPRISED TO SEE OCCASIONAL GUSTS TO 20-25 KT RIGHT ALONG
THE COAST DURING THE AFTERNOON HOURS TODAY AND SATURDAY. WINDS
SHOULD TEMPORARILY INCREASE SUNDAY BEFORE RELAXING AGAIN EARLY
NEXT WEEK.

THE GENERAL WEATHER PATTERN WILL CONTINUE TO PRODUCE LOCALLY
GENERATED WIND WAVES/FRESH SWELL....LEADING TO CHOPPY SEAS...BUT
WITH TOTAL WAVE HEIGHTS GENERALLY REMAINING 5 FT OR LESS THROUGH
MUCH OF NEXT WEEK. /NEUMAN

&&

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

&&

$$

MORE WEATHER INFORMATION ONLINE AT...HTTP://WEATHER.GOV/PORTLAND

INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
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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