Area Forecast Discussion
Issued by NWS Portland, OR

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000
FXUS66 KPQR 271549
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND
848 AM PDT MON APR 27 2015

.SYNOPSIS...WILL HAVE A MILD AND SUNNY SPRING DAY TODAY. BUT IT IS
SHORT LIVED AS AREA WILL SEE A RETURN TO COOLER AND MORE UNSETTLED
WEATHER FOR TUE AND WED. SOMEWHAT UNSURE...BUT SEEMS WILL HAVE
SEASONABLE TEMPERATURES WITH SOME MINOR THREAT OF SHOWERS FOR REST OF
THE WEEK INTO NEXT WEEKEND.
&&

.SHORT TERM...TODAY THROUGH WEDNESDAY...WARM FRONT HAS LIFT N OF THE
REGION THIS AM. PLENTY OF SUNSHINE ACROSS THE REGION...EXCEPT FOR
AREAS OF LOW CLOUDS AND FOG THAT FORMED OVER MUCH OF THE INTERIOR.
MOST OF THESE CLOUDS ARE IN THE COAST RANGE AND NEARBY WEST HALF OF
THE WILLAMETTE VALLEY. THESE CLOUDS WILL BURN OFF LATER THIS AM.

OVERALL...MOST AREAS WILL GET INTO THE 60S ALONG THE COAST. FURTHER
INLAND...AIR MASS IS MILD WITH 850 MB TEMPS RUNNING AROUND 10 TO 14
DEG. WITH THIS...SEEMS REASONABLE THAT WILL GET INTO THE MID AND
UPPER 70S OVER THE INTERIOR LOWLANDS.

THE NEXT PACIFIC FRONT IS ALREADY NEAR 140W AND WILL CAUSE CLOUDS TO
INCREASE TONIGHT. WHILE THIS FRONT INVOLVES THE REMNANTS OF A KONA
LOW WHICH WAS LINGERING NEAR HAWAII FOR THE PAST SEVERAL DAYS...MOST
OF THE ASSOCIATED DYNAMICS AND MOISTURE APPEAR TO BE HEADED FOR THE
BC COAST WITH THE TAIL END OF THE FRONT DRAGGING ACROSS THE PAC NW
TUE. THERE SHOULD STILL BE ENOUGH DYNAMICS/MOISTURE IN PLACE FOR SOME
LIGHT RAIN ACROSS MOST OF THE DISTRICT WITH THE HEAVIEST
AMOUNTS...ONLY 0.25-0.50 INCH...LIKELY ALONG THE NORTH COAST AND
COAST RANGE. THERE IS A DECENT THERMAL SIGNATURE TO THIS COLD
FRONT...WITH 00Z ECMWF DROPPING 850 MB TEMPS BACK DOWN TO AROUND +4
DEG C ACROSS OUR AREA BY MIDDAY TUE. WITH PLENTY OF CLOUDS AND
MOISTURE AROUND...MANY LOCATIONS MAY STRUGGLE TO CLIMB ABOVE 60
DEGREES TUE.

A FOLLOWING DISTURBANCE WILL PUSH THROUGH THE FCST AREA WED. THIS
SYSTEM IS PRESENTLY JUST SOUTH OF THE ALEUTIANS NEAR 160W. MODELS
SHOW A DECENT COLD POCKET ALOFT WITH THIS SYSTEM...WITH PLENTY OF
SHALLOW INSTABILITY. THEREFORE SHOWERS ARE A GOOD BET FOR WED...AND
SNOW LEVELS MAY AGAIN BE DOWN NEAR THE CASCADE PASSES. DEPENDING ON
THE MAGNITUDE OF COLD AIR ALOFT THERE IS AN OFF CHANCE OF THUNDER FOR
OUR NORTHERN ZONES WED...BUT CONFIDENCE IS NOT QUITE HIGH ENOUGH TO
INCLUDE IN THE FORECAST YET.      WEAGLEROCK

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
WEDNESDAY NIGHT THROUGH SUNDAY... RESIDUAL SHOWERS MAY LINGER IN THE
NORTHERN ZONES WEDNESDAY NIGHT. THEN GENERALLY ZONAL FLOW ALOFT WILL
LIKELY MAINTAIN OVER THE REGION FOR THE SECOND HALF OF THE WEEK. A
FEW WEAK DISTURBANCES MAY BRING OCCASIONAL LIGHT RAIN AT TIMES BUT
NOT POSSIBLE TO PINPOINT THE STRENGTH OF THESE IMPULSES AND TIMING OF
THEIR ARRIVAL AT THIS TIME. THUS WHILE CONFIDENCE IS IMPROVING IN THE
GENERAL PATTERN AND TREND...THE PARTICULARS REFLECT A LOWER
CONFIDENCE FORECAST. THAT SAID...DID CUT BACK POPS A BIT FOR THURSDAY
ONWARD GIVEN THE RECENT TRENDING OF THE MODELS...BUT GIVEN SOME
UNCERTAINTY DID KEEP SLIGHT CHANCE FOR THE NORTHERN
ZONES...CASCADES...AND PORTIONS OF THE COAST/COAST RANGE AT TIMES.
DESPITE THIS...SUSPECT THAT MANY LOCATIONS...INCLUDING THE
CENTRAL/SOUTH WILLAMETTE VALLEY...LIKELY REMAIN LARGELY DRY FROM
FRIDAY INTO EARLY NEXT NEXT. TEMPERATURES THROUGH THE EXTENDED PERIOD
LOOK TO REMAIN NEAR NORMAL THROUGH EARLY NEXT WEEK.   CULLEN
&&

.AVIATION...MOSTLY VFR WITH POCKETS OF IFR/LIFR FOG IN THE CENTRAL
AND SOUTH WILLAMETTE VALLEY AND ALONG THE COLUMBIA RIVER NEAR
KPDX. EXPECT THIS FOG TO BURN OFF BY 17Z. WIDESPREAD VFR
CONDITIONS RETURN THIS AFTERNOON AND EVENING UNDER WEAK HIGH
PRESSURE. A MIXTURE OF FLIGHT CONDITIONS RETURN TONIGHT AS
ANOTHER FRONT APPROACHES THE REGION...WITH MVFR TO IFR CIGS
POSSIBLE AT THE COAST AFTER 05Z AND INLAND AFTER 10Z.

KPDX AND APPROACHES...EXPECT IFR FOG ALONG THE COLUMBIA RIVER TO
BURN OFF BY 17Z WITH VFR CONDITIONS EXPECTED THIS AFTERNOON AND
EVENING. BREEZY EASTERLY WINDS MAY DEVELOP NEAR THE GORGE THIS
AFTERNOON...BUT CONFIDENCE IS LOW THAT IT WILL MATERIALIZE. MVFR
CIGS POSSIBLE AFTER 15Z TOMORROW AS ANOTHER FRONT MOVES THROUGH
THE REGION.
&&

.MARINE...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...FAIRLY BENIGN
CONDITIONS ARE EXPECTED TODAY WITH WEAK HIGH PRES OVER THE WATERS.
EXPECT SOUTHERLY WINDS OF 5 TO 10 KT AND SEAS AT 5 TO 7 FT.
SOUTHERLY WINDS WILL INCREASE AGAIN LATE THIS EVENING AHEAD OF THE
NEXT APPROACHING FRONT. EXPECT A PERIOD OF 15 TO 20 KT WINDS WITH
GUSTS TO 25 KT LASTING INTO TUE MORNING AS THE FRONT MOVES THROUGH
THE WATERS. WINDS WILL TURN WEAK AND TURN WESTERLY BEHIND THE
FRONT TUE AFTERNOON. EXPECT INCREASING WESTERLY SWELL TO BUILD IN
BEHIND THE FRONT LATER TUE...LIKELY PUSHING SEAS BACK NEAR OR JUST
ABOVE 10 FT THROUGH WED.

HIGH PRESSURE RETURNS TO THE WATERS FOR THE REMAINDER OF THE
WEEK...WITH THERMAL SURFACE LOW PRESSURE ALONG THE NORTHERN
CALIFORNIA COAST. THIS COMMONLY BRINGS ADVISORY LEVEL WIND GUSTS
TO THE CENTRAL OREGON WATERS DURING THE AFTERNOONS AND EVENINGS.
PYLE
&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS FOR LATE THIS EVENING THROUGH
       TUE AM ON ALL COASTAL WATERS.
&&

$$

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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