Area Forecast Discussion
Issued by NWS Portland, OR

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FXUS66 KPQR 181651
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND
950 AM PDT SAT APR 18 2015

.SYNOPSIS...SUNNY AND WARM WEATHER IS EXPECTED THROUGH MONDAY AS HIGH
PRESSURE DOMINATES THE PACIFIC NORTHWEST. TEMPERATURES WILL WARM UP A
BIT EACH DAY...LIKELY REACHING 80 DEGREES FOR SOME INLAND AREAS BY
MONDAY. COASTAL AREAS WILL BE COOLER...BUT SHOULD STILL SEE PLENTY OF
SUNSHINE THIS WEEKEND. AN UPPER TROUGH MAY BRING A FEW SHOWERS AS
EARLY AS TUESDAY...WITH UNSETTLED WEATHER AND COOLER TEMPERATURES
EXPECTED FOR THE REST OF THE WEEK.

&&

.MORNING UPDATE...VERY FEW CHANGES WERE MADE TO THE FORECAST FOR THE
MORNING UPDATE...AS THE PREVIOUS SHIFT APPEARS TO HAVE A GOOD HANDLE
ON THINGS. LOOKS LIKE IT WAS A GOOD MOVE TO BUMP FCST TEMPS UPWARD A
COUPLE DEGREES TODAY THROUGH MONDAY...WITH 850 MB TEMPS ALREADY NEAR
+10 DEG C ON THE 12Z SALEM SOUNDING AND ONLY EXPECTED TO WARM AS THE
DAY PROGRESSES. LOWER TO MID 70S LOOK LIKELY TODAY FOR OUR INLAND
VALLEYS...WITH SOME LOWER 80S POSSIBLE AS EARLY AS SUNDAY AND EVEN
MORE LIKELY MONDAY AS 850 MB TEMPS PUSH WELL INTO THE TEENS. LOOKS
LIKE A NICE SUNNY WEEKEND ALONG THE COAST AS WELL...ALBEIT A LITTLE
BLUSTERY AND COOLER THAN INLAND AREAS. STRATUS MAY RETURN ALONG THE
COAST BY MONDAY AS THERMAL LOW PRESSURE DEVELOPS INLAND...RESULTING
IN A COOLDOWN ALONG THE COAST. THE DEEPENING MARINE LAYER WILL
EVENTUALLY PUSH INLAND...BUT PROBABLY NOT UNTIL MONDAY NIGHT OR
TUESDAY.  WEAGLE

.SHORT TERM...TODAY THROUGH TUESDAY...HIGH PRESSURE IS BUILDING OVER
THE PACIFIC NW THIS MORNING ALOFT AND SURFACE...AND WILL HOLD THROUGH
TUESDAY. SKIES ARE CLEAR EARLY THIS MORNING...AND RADIATION COOLING
MAY LEAD TO SOME PATCHY STRATUS/FOG AROUND SUNRISE ALONG THE
IMMEDIATE COAST AND IN THE INTERIOR VALLEYS. HOWEVER...THE ATMOSPHERE
IS RATHER DRY WITH TEMPERATURE/DEW POINT DEPRESSIONS AROUND 10
DEGREES INLAND...AND THINK THE COAST STANDS THE BEST CHANCE FOR SOME
SHALLOW FOG.

N-NW WINDS ARE ALREADY OBSERVED ALONG THE COAST AND WILL REMAIN
THROUGH TONIGHT AS THE HIGH PRESSURE SETTLES ACROSS OREGON AND
WASHINGTON AND A THERMAL TROUGH HOLDS OVER NORTHERN CALIFORNIA. ANY
FOG EARLY THIS MORNING WILL QUICKLY CLEAR AND EXPECT TEMPERATURES TO
RISE INTO THE LOW TO MID 70S FOR THE INTERIOR VALLEYS AND THE UPPER
60S FOR THE COAST THIS AFTERNOON.

THE THERMAL TROUGH WILL EXTEND SLIGHTLY NORTHWARD AND OFFSHORE
TONIGHT ALLOWING THE INLAND WINDS TO BECOME OFF SHORE. THIS WILL
RESULT IN DRIER AIR OVER OREGON AND WASHINGTON TONIGHT AND A LACK OF
FOG/CLOUDS. SUNDAY WILL POSSIBLY BE THE WARMEST DAY OF THE YEAR SO
FAR AND EXPECT THE INTERIOR VALLEYS TO WARM INTO THE UPPER 70S.
THE PRESSURE PATTERN WILL CHANGE VERY LITTLE SUNDAY NIGHT AND
MONDAY...AND EXPECT EVEN WARMER TEMPERATURES FOR MONDAY.

THE RIDGE WILL SHIFT INLAND MONDAY NIGHT AS AN UPPER TROUGH
APPROACHES...WITH ONSHORE FLOW BRINGING COOLER AND MOISTER AIR TO
COASTAL REGIONS TUESDAY MORNING. EXPECT MARINE STRATUS TO RETURN TO
THE COAST AND BE DEEP ENOUGH TO MOVE THROUGH THE COASTAL GAPS INTO
PARTS OF THE WILLAMETTE VALLEY. THESE CLOUDS COMBINED WITH A PASSING
TROUGH WILL RESULT IN COOLER TEMPERATURE TUESDAY AFTERNOON WITH
INLAND HIGHS BACK IN THE 60S AND COASTAL HIGHS IN THE 50S.

THE UPPER TROUGH MAY HELP BRING SOME MONSOONAL MOISTURE FROM
CALIFORNIA AND ARIZONA NORTHWARD FOR SOME AFTERNOON SHOWERS OVER THE
OREGON AND WASHINGTON CASCADES TUESDAY AFTERNOON AND POSSIBLY SOME
THUNDERSTORMS ALONG THE CASCADE CREST. HOWEVER...THE BEST CHANCE FOR
THUNDERSTORMS WILL BE EAST OF THE CASCADES. TJ

&&

.LONG TERM...TUESDAY NIGHT THROUGH FRIDAY...AN UPPER TROUGH WILL
BRING A CHANCE OF SHOWERS...MAINLY TO THE CASCADES TUESDAY NIGHT.
WEDNESDAY WILL BE CLOUDY AND COOL BEHIND THE TROUGH. A COUPLE OF
COLD FRONTS WILL INCREASE RAIN AND MOUNTAIN SNOW CHANCES FOR THURSDAY
AND FRIDAY.  TJ

&&

.AVIATION...HIGH PRES WITH DRY STABLE FLOW ALOFT. IFR STRATUS AND
FOG AT THE COAST SHOULD DISSIPATE BY 18Z AS GUSTY N WINDS
INCREASE ALONG THE COAST. THEN EXPECT WIDESPREAD VFR THROUGH SUN
AM. BREEZY NORTHERLY WINDS SHOULD KEEP ANY FOG OR CLOUDS FROM
FORMING AT THE COAST TONIGHT.

KPDX AND APPROACHES...VFR UNDER DRY STABLE AIR MASS. NO ADVERSE WX
IMPACTS THROUGH SUN AM. PYLE/ROCKEY.

&&

.MARINE...HIGH PRES OVER THE REGION...WITH THERMAL LOW PRES OVER
NW CALIF INTO FAR SW OREGON. THIS WILL MAINTAIN GUSTY N WINDS.
WHILE THE STRONGEST WINDS ON S OREGON COASTAL WATERS...SHOULD
STILL HAVE GUSTS 20 TO 25 KT N OF CASCADE HEAD...AND 25 TO 30 KT
TO S. ALSO...WINDS WILL BE STRONGEST DURING THE AFTERNOON AND
EVENING HOURS...SLACKENING LATE AT NIGHT. SEAS GENERALLY 8 TO 10
FT TODAY AND TONIGHT...BUT WILL EASE BACK A TAD...WITH 6 TO 9 FT
SUN AND MON.

THE NEXT FRONT WILL MOVE THROUGH THE WATERS ON TUE. THEN THE LONGER
RANGE SHOWS HIGH PRES OVER THE NE PAC STRENGTHENING DURING THE
MIDDLE OF NEXT WEEK..WITH NW WINDS GUSTING 20 TO 30 KT AT TIMES.
ALSO EXPECT INCREASING NW SWELL TO PUSH SEAS BACK INTO THE LOW TO
MID TEENS STARTING WED. PYLE

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL NOON PDT SUNDAY FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 4 PM
     THIS AFTERNOON TO 8 PM PDT THIS EVENING.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 4 AM TO
     8 AM PDT SUNDAY.

&&

$$

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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