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
723
FXUS66 KPQR 101640
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
838 AM PST WED FEB 10 2016

.SYNOPSIS...MILD AIR MASS TO REMAIN OVER THE REGION THROUGH FRI.
WEAK FRONTS OFFSHORE WILL BRUSH THE NW TODAY AND THU...WITH VARIABLE
CLOUDINESS ACROSS THE REGION...ALONG WITH SOME SPOTTY LIGHT RAIN
ALONG THE COAST AND POSSIBLY INLAND. THAT CHANGES BY FRI...AS FIRST
IN A SERIES OF FRONTS PUSH INTO THE PAC NW. SHOWERY ON SATURDAY...BUT
MORE RAIN ARRIVES ON SUNDAY.

&&

.SHORT TERM...TODAY THROUGH SATURDAY...SATELLITE IMAGERY THIS MORNING
SHOWS A WEAKENING MID LEVEL FRONT SLOWLY SHIFTING EASTWARD INTO THE
PACIFIC NORTHWEST. A FEW SHOWERS HAVE DEVELOPED ALONG AN 850MB
BOUNDARY ACROSS FAR NORTHWEST OREGON AND SOUTHWEST WASHINGTON. THIS
BOUNDARY IS EXPECTED TO WEAKEN AS IT SHIFTS INLAND SO HAVE KEPT MOST
LOCATIONS WITH CHANCE OR SLIGHT CHANCE POPS FOR TODAY. GIVEN THE
AFOREMENTIONED BOUNDARY WILL HANG ACROSS THE AREA OVERNIGHT...CANNOT
RULE OUT A LIGHT SHOWER OR TWO...BUT IN GENERAL...ANY RAIN THAT FALLS
SHOULD BE LIGHT AND RATHER ISOLATED.

A LOW PRESSURE SYSTEM IS THEN FORECAST TO DEEPEN AS IT MOVES
NORTHWARD ALONG 140W ON THURSDAY. THIS WILL SPREAD A WARM FRONT
NORTHWARD AND INCREASE RAIN CHANCES ACROSS THE AREA ON THURSDAY. AT
THIS POINT...THE DEEPEST MOISTURE AND BEST DYNAMICS WILL PRIMARILY
STAY OFFSHORE SO KEPT THE TREND OF KEEPING THE HIGHEST POPS ACROSS
OUR FAR NORTHWEST ZONES AND LOWEST POPS ACROSS LANE AND LINN
COUNTIES. NONETHELESS...IT LOOKS LIKE A GOOD PORTION OF THE FORECAST
AREA WILL SEE AT LEAST SOME RAIN ON THURSDAY...ESPECIALLY DURING THE
MIDDAY AND AFTERNOON HOURS.

THE TRAILING COLD FRONT SHOULD THEN PUSH INTO THE PACIFIC NORTHWEST
AT SOME POINT THURSDAY NIGHT OR FRIDAY MORNING. THIS WILL LIKELY
SPREAD ANOTHER ROUND OF RAIN INTO THE AREA DURING THIS PERIOD. SNOW
LEVELS SHOULD LOWERING INTO THE 4000-4500 FT RANGE ON FRIDAY. AS POST
FRONTAL SHOWERS SPREAD INTO THE PACIFIC NORTHWEST LATE FRIDAY AND
FRIDAY NIGHT...SNOW LEVELS MAY LOWER ANOTHER 500 FT OR SO AND BRING
SOME IMPACTS TO TRAVEL IN THE CASCADES. SNOW ACCUMULATIONS IN THE
CASCADES APPEAR LIKELY TO REMAIN UNDER WINTER WX ADVISORY CRITERIA
THOUGH.

A WARMER AND WETTER STORM SYSTEM APPEARS ON TRACK FOR SATURDAY NIGHT.
/NEUMAN



.LONG TERM...SATURDAY THROUGH TUESDAY...
COOLER ON SATURDAY...WITH SHOWERS OVER THE REGION. SNOW LEVELS
SITTING AROUND 3500 TO 4000 FEET ON SAT...WITH SOME NEW SNOW EXPECTED
OVER THE CASCADES. NOT A LOT...BUT COULD SEE 3 TO 8 INCHES OF NEW
SNOW AT THE PASSES AND ABOVE. RATHER PROGRESSIVE PATTERN OVER THE
PAC...WITH ANOTHER FRONT ARRIVING ON SUN. HAVE INCREASES PROB OF RAIN
ON SUNDAY. BRIEF BREAK ON MON...BUT LOOKS WET AFTERWARDS AS YET
ANOTHER FRONT ARRIVES ON TUE. REST OF NEXT WEEK LOOKS RATHER CLOUDY
AND WET...WITH SNOW LEVELS BOUNCING FROM 3500 TO 5500 FT.   ROCKEY.

&&

.AVIATION...MOST AREAS VFR THIS MORNING. ALTHOUGH THERE ARE
POCKETS OF IFR CIGS IN THE SOUTH WILLAMETTE VALLEY NEAR KEUG AND
KCVO. A WEAK FRONT IS BRINGING RAIN...MVFR AND GUSTY SOUTH WINDS
UP TO 25 KT TO THE COAST THIS MORNING. THE FRONT WILL WEAKEN AS IT
MOVES INLAND BUT WILL LIKELY PRODUCE MVFR CONDITIONS FOR THE COAST
RANGE AND AREAS NORTH OF PORTLAND THIS AFTERNOON AND EVENING. MAY
SEE BRIEF PERIODIC MVFR CIGS BETWEEN SALEM AND PORTLAND...BUT
THINK VFR WILL GENERALLY DOMINATE SOUTH OF PORTLAND EAST OF THE
COAST RANGE. EXPECT MVFR VSBYS FOR THE COAST AND PARTS OF THE
WILLAMETTE VALLEY OVERNIGHT TONIGHT. A WARM FRONT WILL CONTINUE
THE CHANCE FOR MVFR CONDITIONS THURSDAY MORNING.

KPDX AND APPROACHES...VFR NEXT 24 HRS. THERE MAY BE BRIEF MVFR
CONDITIONS AND RAIN THIS AFTERNOON AND EVENING AS A WEAK FRONT
MOVES ACROSS THE AREA. CLOUDY WITH VFR CIGS AND VSBYS TONIGHT. TJ
&&

.MARINE...BUOY 89 AND BUOY 50 ARE SHOWING MARGINAL SMALL CRAFT
GUSTS THIS MORNING AND THE FORECAST CONFIDENCE FOR A LOW-END
SMALL CRAFT ADVISORY FOR TODAY HAS IMPROVED. THE SEAS AT THE BUOYS
ARE 1 TO 2 FT BELOW GUIDANCE THIS MORNING AND HAVE ADJUSTED TODAYS
SWELL FORECAST ACCORDINGLY. THE SEAS STILL LOOK ON TRACK TO BUILD
TO 10 FT OVERNIGHT TONIGHT AND TO ABOVE 10 FT THURSDAY...AS A
LONGER-PERIOD NW SWELL MOVES THROUGH THE WATERS. THERE IS ANOTHER
CHANCE FOR SMALL CRAFT ADVISORY WINDS THURSDAY AFTERNOON AND
EVENING. A COMPLEX LOW OFFSHORE WILL RESULT IN ELEVATED SEAS
THROUGH THE WEEKEND. TJ

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 PM PST THIS AFTERNOON
    FOR WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT TO 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 10 PM THIS EVENING
     TO 4 PM PST FRIDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA
    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.



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