Area Forecast Discussion
Issued by NWS Portland, OR

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FXUS66 KPQR 182203
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
301 PM PDT THU SEP 18 2014

.SYNOPSIS...DRIER WEATHER SHOULD BE ON TAP FOR TONIGHT AND FRIDAY AS
HIGH PRESSURE BEGINS BUILDING INTO THE REGION. THE MAIN EXCEPTION TO
THIS WILL BE ACROSS SOUTHWEST WASHINGTON AND THE EXTREME NORTH OREGON
COAST ON FRIDAY WHERE A FEW LIGHT SHOWERS MAY OCCUR AS A DYING FRONT
MOVES INTO THE REGION. OFFSHORE FLOW AND HIGH PRESSURE WILL BRING
WARM TEMPERATURES OVER THE WEEKEND. COOLER UNSETTLED WEATHER MAY
RETURN TOWARDS THE MIDDLE OF NEXT WEEK.

&&

.SHORT TERM...FOR TONIGHT...VISIBLE SATELLITE IMAGERY THIS AFTERNOON
SHOWS THE REGION CAUGHT BETWEEN A LOW PRESSURE SYSTEM MOVING
SOUTHWARD OFF THE CALIFORNIA COAST AND WESTERLY FLOW PUNCHING INTO
BRITISH COLUMBIA. ASIDE FROM THE CENTRAL OREGON COAST...MOSTLY CLOUDY
TO CLOUDY SKIES ABOUND. A LOOP OF DOPPLER RADAR SHOWS MOST SHOWER
ACTIVITY HAS WEAKENED AND MOVED EAST OF THE CASCADES TODAY. RAINFALL
AMOUNTS WERE GENERALLY BETWEEN A HUNDREDTH AND FIVE HUNDREDTHS OF AN
INCH WITH A COUPLE LOCATIONS NOT EVEN MEASURING. FORTUNATELY...A FEW
AREAS RECEIVED BETWEEN A TENTH AND A QUARTER OF AN INCH OF RAIN OUT
OF THIS STORM...PRIMARILY ACROSS THE WILLAPA HILLS...AND EXTREME
SOUTHEASTERN LANE COUNTY. A FEW LIGHT SHOWERS AND DRIZZLE CONTINUE
ACROSS PORTIONS OF THE CASCADES...BUT ADDITIONAL QPF WILL BE MINIMAL.
AS SURFACE HIGH PRESSURE BUILDS NORTHEASTWARD INTO THE REGION THIS
EVENING...EXPECT SHOWER ACTIVITY TO CONTINUE TO DECREASE.

FOR FRIDAY...BUILDING 500MB HEIGHTS AND SURFACE HIGH PRESSURE NOSING
INTO THE REGION FROM THE SOUTHWEST SHOULD RESULT IN DECREASING CLOUD
COVER.A WEAK FRONT DIVING SOUTHEASTWARD WILL PUSH INTO SOUTHWEST
WASHINGTON MIDDAY FRIDAY...BRINGING A CHANCE FOR LIGHT RAIN TO
PRIMARILY THE COAST. MEASURABLE RAIN WILL BE POSSIBLE...BUT EVEN A
TENTH OF AN INCH APPEARS QUITE UNLIKELY.

FOR SATURDAY AND SUNDAY...INCREASING OFFSHORE FLOW WILL BRING MUCH
WARMER TEMPERATURES TO THE REGION. EXPECT THE WARMEST TEMPERATURES
ALONG THE COAST AND PERHAPS THE SOUTHERN WILLAMETTE VALLEY ON
SATURDAY. EUGENE WILL STAND A GOOD CHANCE TO ADD TO THEIR RECORD 35
DAYS OF 90F OR PLUS OR HIGHER IN 2014. AS THERMAL LOW PRESSURE SHIFTS
NORTHWARD TO OFF WASHINGTON LATE SATURDAY INTO SUNDAY...COOLER MARINE
AIR SHOULD SPREAD INTO COASTAL LOCATIONS AND PERHAPS THE SOUTHERN
WILLAMETTE VALLEY SUNDAY...BUT CONFIDENCE IN THE DETAILS REMAINS
SOMEWHAT LOW.

EAST WINDS SATURDAY AND MUCH LOWER RELATIVE HUMIDITIES FOR MUCH OF
THE WEEKEND SHOULD ONCE AGAIN PRODUCE CONDITIONS MORE FAVORABLE FOR
WILDFIRE GROWTH...ALBEIT NOT LIKELY EXPLOSIVE GROWTH. AS A
RESULT...AT LEAST MODEST AMOUNTS OF SMOKE SHOULD SPREAD BACK INTO THE
WILLAMETTE VALLEY FROM THE 36 PIT AND DECEPTION COMPLEX FIRES IF THEY
ARE NOT CONTAINED. /NEUMAN


.LONG TERM...MONDAY THROUGH THURSDAY...COOLER TEMPERATURES AND AN
INCREASE IN CLOUDS ARE EXPECTED TO RETURN TO THE REGION ON MONDAY
AHEAD OF AN APPROACHING UPPER LEVEL TROUGH. THE MODELS CONTINUE TO
HINT AT A WIDESPREAD RAIN EVENT STARTING ON WEDNESDAY...WITH RAIN
LIKELY CONTINUING THROUGHOUT THE EXTENDED PERIOD. TEMPERATURES IN
THE EXTENDED WILL GENERALLY TREND TOWARDS SEASONAL NORMALS.

&&

.AVIATION...STILL SOME AREAS OF MVFR CIGS LINGERING OVER NW OREGON
EARLY THIS AFTERNOON...BUT THE OVERALL TREND OF RETURNING TO VFR
CONDITIONS THROUGH THE REST OF THE AFTERNOON AND EVENING IS EXPECTED
TO CONTINUE. TRENDS EXPECTED TO REVERSE AGAIN OVERNIGHT...WITH
WIDESPREAD MVFR CIGS EXPECTED TO REDEVELOP BETWEEN 06Z AND 12Z AS A
WEAK FRONT APPROACHES...AND MVFR CIGS CONTINUE THROUGH THE EARLY
MORNING THROUGH 16Z.

KPDX AND APPROACHES...PRIMARILY VFR CONDITIONS THROUGH 10Z TONIGHT.
MVFR CIGS EXPECTED TO REDEVELOP AFTER 10Z TONIGHT AND CONTINUE
THROUGH 16Z FRI.
&&

.MARINE...WINDS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT CRITERIA
THROUGH FRIDAY MORNING. THERMAL LOW PRESSURE IS EXPECTED TO
DEVELOP ALONG THE NORTHERN CALIFORNIA COAST LATE FRIDAY AND EXTEND
NORTH ALONG THE OREGON COAST FRIDAY NIGHT INTO SATURDAY. THIS WILL
LIKELY RESULT IN SMALL CRAFT ADVISORY NORTHERLIES SPREADING NORTH
THROUGH THE WATERS. WINDS WILL DECREASE SATURDAY NIGHT...BUT A
SOUTHERLY WIND REVERSAL WILL SPREAD UP THE COAST SATURDAY NIGHT AND
SUNDAY.

SEAS ARE EXPECTED TO BE AROUND 5 TO 6 FT TODAY AND FRIDAY WITH A MIX
OF A LONG PERIOD SOUTH SWELL AND A SHORTER PERIOD NW SWELL. SEAS
THEN EXPECTED TO BUILD TO 8 OR 9 FT SAT IN THE STRENGTHENING
NORTHERLIES...DROPPING BACK DOWN TO AROUND 5 FT SUNDAY.

&&

.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 AS THE FORECAST AREA.



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