Area Forecast Discussion
Issued by NWS Seattle/Tacoma, WA

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000
FXUS66 KSEW 291056
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
900 PM PDT TUE JUL 28 2015

.SYNOPSIS...AN UPPER RIDGE WILL KEEP DRY AND VERY WARM CONDITIONS
OVER THE AREA THROUGH THE WEEKEND. WARM TO HOT WEATHER WILL PERSIST
INTO EARLY NEXT WEEK AS THE UPPER RIDGE REMAINS ANCHORED OVER THE
WESTERN US.

&&

.SHORT TERM...UPPER LEVEL HEIGHTS WILL RISE AS BROAD UPPER LEVEL
RIDGE CONTINUES TO BUILD OVER THE WESTERN US. LOW CLOUDS THIS
MORNING WILL REMAIN LIMITED TO THE NORTH COAST...WITH SHALLOW GROUND
FOG POSSIBLE OVER THE SOUTH INTERIOR THROUGH THE CHEHALIS GAP INTO
THE CENTRAL WA COAST. THIS WILL BURN OFF QUICKLY THIS MORNING AS
TEMPERATURES WARM THIS MORNING.

CLEAR SKIES COUPLED WITH THE WARMING AND SUBSIDENCE ALOFT ASSOCIATED
WITH THE BUILDING RIDGE WILL BOOST TEMPS TODAY AND THU. FOR
TODAY...HIGH TEMPERATURES WILL RISE INTO THE 80S AND OVER MUCH OF
THE CENTRAL INTERIOR AND EVEN LOW 90S OVER THE SOUTH. THE COAST AND
NORTH WILL REMAIN IN THE 70S TO LOW 80S. THURSDAY TEMPERATURES WILL
RUN AROUND 5 DEGREES WARMER OVER ALL AREAS...WITH THE CENTRAL SOUND
AND SOUTH INTERIOR RISING INTO THE UPPER 80S TO LOW 90S. FRIDAY WILL
SEE SIMILAR TEMPERATURES AS THURSDAY...REACHING INTO THE LOW 90S
ESPECIALLY OVER THE SOUTH. CLEAR SKIES AND WEAK LOW LEVEL ONSHORE
FLOW WILL HELP OVERNIGHT TEMPERATURES GENERALLY DIP DOWN INTO THE
MID TO UPPER 50S OVER MOST AREAS...WHICH WILL GIVE SOME RELIEF TO
THE VERY WARM DAYTIME HIGHS.

.LONG TERM... THE BROAD UPPER RIDGE WILL REMAIN SOLIDLY IN POSITION
OVER THE WESTERN US THROUGH SUNDAY...KEEPING DRY AND VERY WARM
CONDITIONS OVER THE REGION. HIGH TEMPERATURES OVER MUCH OF THE
INTERIOR WILL REMAIN IN THE MID TO UPPER 80S AND LOW TO MID 90S
SATURDAY AND SUNDAY...AND MID TO UPPER 70S ALONG THE COAST.
OVERNIGHT TEMPERATURES WILL CONTINUE TO COOL INTO THE UPPER 50S
HELPING MITIGATE THE IMPACTS OF THE WARM HIGH TEMPERATURES. MEDIUM
RANGE MODELS HINT AT THE RIDGE SHIFTING EAST A BIT SUNDAY WHICH WILL
ALLOW HEIGHTS TO DIP SOMEWHAT...BUT EXPECT TEMPERATURES TO REMAIN
CONSISTENTLY HIGH THROUGH MONDAY BEFORE COMING DOWN INTO THE MID 80S
OVER THE INTERIOR TUESDAY.

&&

.CLIMATE...ON THIS DATE BACK IN 2009 THE WARMEST DAY ON RECORD IN
SEATTLE OCCURRED WITH A HIGH OF 103 DEGREES. IN ADDITION TO BEING
THE WARMEST DAY ON RECORD JULY 29TH IS ALSO THE DRIEST DAY ON RECORD
AT SEATTLE-TACOMA AIRPORT. SINCE RECORDS STARTED IN 1945 THERE HAS
BEEN A TOTAL OF JUST 0.31 INCHES OF RAIN RECORDED ON THIS DAY.
MEASURABLE RAIN HAS OCCURRED ONLY 4 TIMES ( 0.17 INCHES 1993, 0.11
INCHES 2008, 0.02 INCHES 1955 AND 0.01 INCHES IN 1981 ). FELTON

&&

.AVIATION...FLAT UPPER LEVEL RIDGE OVER WESTERN WASHINGTON WITH
WESTERLY FLOW ALOFT TODAY. LIGHT ONSHORE FLOW IN THE LOWER LEVELS.

CLEAR SKIES OVER MOST OF WESTERN WESTERN WASHINGTON EARLY THIS
MORNING. THE EXCEPTION IS SOME LOW CLOUDS ALONG THE NORTH COAST.
THESE CLOUDS WILL BURN OFF BY MID MORNING. PATCHY FOG IS POSSIBLE
ALONG THE COAST INTO THE LOWER CHEHALIS VALLEY EARLY THIS MORNING.
SOME HIGH CLOUDS WILL PASS BY MAINLY TO THE NORTH TODAY AND TONIGHT.
FELTON

KSEA...CLEAR SKIES WITH LIGHT NORTHERLY WINDS. FELTON

&&

.MARINE...HIGH PRES OFFSHORE WITH LOWER PRES E OF THE CASCADES WILL
KEEP THE FLOW ONSHORE INTO THE WEEKEND. THE FLOW WILL BRIEFLY BECOME
NORTHERLY OF LIGHT OFFSHORE EARLY THURSDAY AND FRIDAY MORNING WITH A
THERMALLY INDUCED TROUGH OF LOW PRESSURE TRYING TO SET UP ALONG THE
COAST. FELTON

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE. PZ...NONE.

&&

$$

WWW.WEATHER.GOV/SEATTLE

AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION CAN BE SEEN AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML



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