Area Forecast Discussion
Issued by NWS Portland, OR

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FXUS66 KPQR 281049
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
345 AM PDT TUE JUL 28 2015

.SYNOPSIS...HIGH PRESSURE ALOFT BUILDING INTO THE REGION WILL BRING A
DRAMATIC WARM UP TODAY. EXPECT THE HOTTEST TEMPERATURES TO OCCUR
WEDNESDAY THROUGH FRIDAY...BUT TEMPERATURES IN THE WILLAMETTE VALLEY
MAY STILL BE FLIRTING WITH 90F OVER THE WEEKEND AND EVEN EARLY NEXT
WEEK.


&&


.SHORT TERM...TODAY THROUGH FRIDAY...FOG PRODUCT EARLY THIS MORNING
REVEALS MARINE STRATUS LARGELY STAYING OFFSHORE UNDER
NORTH-NORTHWESTERLY LOW LEVEL FLOW. A FEW PATCHES OF LOW CLOUDS MAY
STILL DEVELOP ALONG THE LOWER COLUMBIA RIVER...BUT ALL IN ALL...MOST
PEOPLE ACROSS NORTHWEST OREGON AND SOUTHWEST WASHINGTON SHOULD WAKE
UP TO PLENTY OF SUNSHINE THIS MORNING.

UPPER LEVEL HIGH PRESSURE IS CURRENTLY SHIFTING OVER THE REGION AND
WILL BRING A DRAMATIC RETURN TO HOT TEMPERATURES ACROSS THE REGION.
EXPECT TEMPERATURES TO WARM BETWEEN 5 AND 10F TODAY COMPARED TO
YESTERDAY...AND TO WARM ANOTHER 5 TO 10F ON WEDNESDAY. THIS SHOULD
PLACE MANY WILLAMETTE VALLEY AND COLUMBIA RIVER GORGE LOCATIONS WELL
INTO THE 90S ON WEDNESDAY. TEMPERATURES SHOULD WARM ANOTHER COUPLE OF
DEGREES THURSDAY AND LIKELY TIE OR EXCEED THE HOTTEST DAY OF THE YEAR
SO FAR AT MANY LOCATIONS. THERMAL LOW PRESSURE SHOULD SHIFT EAST OF
THE CASCADES LATE THURSDAY...WHICH SHOULD PRODUCE SLIGHTLY COOLER
TEMPERATURES ACROSS THE AREA ON FRIDAY. MANY INTERIOR LOWLAND
LOCATIONS WILL STILL LIKELY BE AROUND 95F THOUGH. ISSUED A HEAT
ADVISORY FOR WEDNESDAY THROUGH FRIDAY FOR THE WILLAMETTE VALLEY AND
COLUMBIA GORGE ZONES WHERE UNCERTAINTY IN SEVERAL DAYS OF HOT
TEMPERATURES IS LOWEST. WILL LET THE DAY SHIFT TAKE IN ANOTHER ROUND
OF MODEL GUIDANCE BEFORE ADDING ADDITIONAL ZONES TO THE ADVISORY.
/NEUMAN


&&


.LONG TERM...FRIDAY NIGHT THROUGH MONDAY...THE UPPER LEVEL RIDGE
AXIS WILL REMAIN OVER THE REGION THROUGH THE WEEKEND...BUT LOWERING
500MB HEIGHTS SHOULD ALLOW A TEMPERATURES TO COOL A COUPLE DEGREES
EACH DAY. NONETHELESS...TEMPERATURES COULD STILL BE FLIRTING WITH
90F ON MONDAY. SOME MID LEVEL MOISTURE AND INSTABILTY WILL ALSO
APPROACH THE REGION FROM THE SOUTH DURING THIS PERIOD. WHILE IT
APPEARS RAIN AND THUNDERSTORMS WILL GENERALLY REMAIN SOUTH AND EAST
OF THE AREA...KEPT A SLIGHT CHANCE MENTION OF THUNDER NEAR THE
OREGON CASCADE CREST DURING MOST OF THIS PERIOD TO ACCOUNT FOR
UNCERTAINTY AT THIS POINT. /NEUMAN


&&


.FIRE WEATHER...PREVIOUS DISCUSSION BELOW...THE LATEST FORECAST
MODELS INDICATE THAT A THERMAL TROUGH WILL BUILD NORTH FROM
CALIFORNIA INTO OREGON ON TUE AND TUE  NIGHT...BRINGING DRYING
NORTHERLY FLOW TO THE REGION. THERE WILL ALSO LIKELY BE SOME LIGHT
EASTERLY WINDS DEVELOPING OVER THE LANE COUNTY CASCADES AND SOUTHERN
WILLAMETTE VALLEY TUE NIGHT INTO WED MORNING. THE THERMAL TROUGH THEN
EXPANDS NORTHWARD INTO THE OREGON CASCADES AND POTENTIALLY INTO THE
WILLAMETTE VALLEY AND ADJACENT FOOTHILLS ON WED AND THU. THIS WILL
BRING ENHANCED INSTABILITY AND MIXING...THAT COMBINED WITH THE
EXPECTED VERY HOT AND DRY CONDITIONS...MAY CREATE CRITICAL FIRE
WEATHER CONDITIONS. ALSO...ALTHOUGH MANY LOCATIONS RECEIVED RAIN OVER
THE WEEKEND...FUELS ARE FORECASTED TO DRY OUT RAPIDLY DURING THE
MIDWEEK PERIOD. A FIRE WEATHER WATCH HAS BEEN ISSUED STARTING WED
AFTERNOON AND CONTINUING THROUGH THU EVENING. THE THERMAL TROUGH IS
CURRENTLY EXPECTED TO START PUSHING EAST OF THE CASCADES ON THU NIGHT
AND FRI. PYLE


&&


.AVIATION...CONDITIONS GENERALLY VFR ACROSS THE REGION EXCEPT FOR
THE NORTH COAST WHERE MVFR MARINE STRATUS IS STARTING TO IMPACT
KAST. MARINE STRATUS LOOKS TO PUSH INTO THE LOWER COLUMBIA RIVER
THIS MORNING...BUT DO NOT THINK THEY WILL REACH THE PORTLAND
METRO. AS SUCH...EXPECT VFR CONDITIONS TODAY AND TONIGHT ACROSS
THE INTERIOR AND CENTRAL COAST. MVFR CIGS ALONG THE NORTH COAST
SHOULD CLEAR LATE THIS MORNING WITH VFR CONDITIONS EXPECTED FOR
THE REST OF TODAY AND TONIGHT. GUSTY NORTHERLY WINDS LIKELY THIS
AFTERNOON/EVENING FOR THE CENTRAL AND SOUTH WILLAMETTE VALLEY AND
CENTRAL COAST WITH GUSTS TO 25 KT POSSIBLE.

KPDX AND APPROACHES...VFR THE NEXT 24 HOURS. GUSTY NORTHERLY WINDS
15 TO 20 KT POSSIBLE BETWEEN 22-05Z. /64

&&

.MARINE...OUR TYPICAL SUMMERTIME PATTERN CONTINUES THE REST OF THE
WEEK. HIGH PRES WILL CONTINUE TO BUILD OVER THE NE PAC WITH
THERMAL LOW PRES STRENGTHENING OVER S OREGON. AS THE THERMAL LOW
STRENGTHENS AND PUSHES FURTHER NORTH WE COULD SEE A FEW BORDERLINE
GALE FORCE GUSTS TO 35 KT OVER THE CENTRAL WATERS TODAY AND
TOMORROW. HOWEVER...CHANCES OF GALES REMAIN FAIRLY LOW SO WILL
KEEP THE CURRENT SMALL CRAFT ADVISORY FOR WINDS AS IS.

GUSTY WINDS WILL LIKELY GENERATE PERIODS OF STEEP AND CHOPPY
CONDITIONS OVER THE WATERS...ESPECIALLY OVER THE CENTRAL WATERS.
EXPECT SEAS TO BUILD THIS AFTERNOON TO AROUND 7 TO 8 FT WITH A
DOMINATE PERIOD AROUND 7 TO 8 SECONDS. DECIDED TO EXTEND THE
SMALL CRAFT ADVISORY FOR SQUARE SEAS THROUGH THU MORNING...BUT WE
WILL LIKELY BE ABLE TO END THIS A FEW HOURS EARLY.


&&


.PQR WATCHES/WARNINGS/ADVISORIES...
OR...FIRE WEATHER WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY
     EVENING FOR ZONE 604-ZONE 605-ZONE 606-ZONE 607-ZONE 608.

     HEAT ADVISORY FROM 11 AM WEDNESDAY TO 9 PM PDT FRIDAY FOR
     CENTRAL COLUMBIA RIVER GORGE-CENTRAL WILLAMETTE VALLEY-
     GREATER PORTLAND METRO AREA-SOUTH WILLAMETTE VALLEY-UPPER
     HOOD RIVER VALLEY-WESTERN COLUMBIA RIVER GORGE.

WA...HEAT ADVISORY FROM 11 AM WEDNESDAY TO 9 PM PDT FRIDAY FOR
     CENTRAL COLUMBIA RIVER GORGE-GREATER VANCOUVER AREA-WESTERN
     COLUMBIA RIVER GORGE.

PZ...SMALL CRAFT ADVISORY FOR WINDS FROM NOON TODAY TO 5 AM PDT
     THURSDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
     CASCADE HEAD OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM NOON TODAY TO
     5 AM PDT THURSDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA
     TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR WINDS UNTIL 5 AM PDT THURSDAY FOR
     COASTAL WATERS FROM CASCADE HEAD OR 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.


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