Heat in Washington, June 7 to 9, 2015

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND
130 PM PDT SUN JUN 7 2015

.SYNOPSIS...HOT WEATHER WILL CONTINUE THROUGH MONDAY FOR ALL BUT THE
IMMEDIATE COAST OF SOUTHWEST WASHINGTON AND NORTHWEST OREGON. AN
UNSEASONABLY STRONG UPPER LEVEL RIDGE WILL MOVE ACROSS THE REGION
TODAY AND MONDAY...KEEPING THE MARINE LAYER VERY SHALLOW AND LIMITED
TO THE COAST THROUGH MONDAY. A GRADUAL COOLDOWN IS EXPECTED TO BEGIN
TUESDAY AS THE UPPER RIDGE MOVES EAST AND ONSHORE FLOW SLOWLY
RETURNS.

&&

.SHORT TERM...THE WELL ADVERTISED STRONG RIDGE ALOFT WILL BE AT ITS
PEAK OVER THE FORECAST AREA OVERNIGHT. UPPER HEIGHTS ARE THEN
EXPECTED TO COME DOWN SOME THROUGH WED AS THE CENTER OF THE RIDGE
MOVES E AND A WEAK SHORT WAVE CLIPS THE REGION TUE NIGHT AND EARLY
WED. SURFACE CHARTS SHOW A WEAK ONSHORE FLOW CONTINUING THROUGH
TUE...THEN INCREASING A BIT TUE NIGHT AND WED AS THE TROUGH ALOFT
MOVES ACROSS.

SKIES WERE CLEAR ACROSS THE FORECAST AREA EARLY SUN AFTERNOON...
EXCEPT FOR AN AREA OF MARINE CLOUDS OVER THE OUTER NORTHERN WATERS
APPROACHING THE COAST. THESE CLOUDS ARE ON TRACK TO REACH THE COAST
THIS EVENING...BUT A NORTHERLY BOUNDARY LAYER FLOW CONTINUING INTO
TUE SUGGESTS THE CLOUDS WILL MAKE LITTLE INLAND PUSH LATER TONIGHT
AND EARLY MON. OVERALL EXPECT THE NEXT COUPLE OF MORNINGS TO HAVE
MAYBE ONLY A LITTLE MORE CLOUD COVER COMPARED WITH THIS PAST
MORNING. WITH LITTLE CHANGE TO THE AIR MASS IN THE LOWER LEVERS
MON...EXPECT TEMPS MON TO AGAIN APPROACH TODAYS HIGHS. TEMPS TUE ARE
LIKELY TO COME DOWN A FEW DEGREES AS UPPER HEIGHTS FALL AND MODEL
FORECAST H8 TEMPS DROP A COUPLE OF DEGREES. IN ADDITION TO A SLIGHT
CHANCE FOR THUNDERSTORMS OVER S PART OF THE CASCADES TUE
AFTERNOON... WILL ADD IN A SLIGHT CHANCE THERE MON AFTERNOON AS
WELL. AS MID AND UPPER LEVEL WINDS VEER AROUND FROM THE E TO S MON
MODEL SOUNDINGS INDICATE AIR MASS BECOMING POTENTIALLY UNSTABLE. AT
THIS POINT DO NOT SEE A GOOD TRIGGER FOR CONVECTION...AND ITS NOT
CLEAR IF THERE MIGHT NOT BE A SUFFICIENT LOW LEVEL CAP TO PROHIBIT
ANY CONVECTION...SO WILL KEEP POPS LIMITED TO SLIGHT CHANCE.

TUE NIGHT AND WED A WEAK SHORTWAVE MOVES THROUGH IN THE WESTERLY
FLOW ALOFT. A SHALLOW NW MARINE PUSH ACCOMPANYING THE SHORT WAVE IS
LIKELY TO SPREAD MORNING CLOUDS INLAND BETTER...PARTICULARLY UP THE
LOWER COLUMBIA AND POTENTIALLY INTO THE N WILLAMETTE VALLEY. WITH
THE MARINE PUSH WILL KEEP A CHANCE OF DRIZZLE ON THE N COAST...BUT A
SWITCH TO SW WINDS ALOFT SHOULD PUSH ANY DEEP INSTABILITY E OF THE
CASCADES. THE PUSH WILL ALSO BRING COOLER AIR TO THE INLAND AREAS...
IN PARTICULAR THE N.

.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY...THE START OF A COOLING
TREND BEGINS LATE WEDNESDAY AS ONSHORE FLOW INCREASES BEHIND A WEAK
UPPER LEVEL TROUGH OVER CANADA. HIGH PRESSURE OVER THE EASTERN
PACIFIC WILL FLATTEN THROUGH THURSDAY AND FRIDAY AS ANOTHER UPPER
LEVEL TROUGH SWEEPS OVER CANADA LATE FRIDAY. MODELS ARE SUGGESTING
ANOTHER SURGE OF ENERGY WILL DIG FURTHER SOUTH OF THE MAIN UPPER
TROUGH...WHICH WOULD EXTEND THE TROUGH OVER THE PACIFIC NORTHWEST
INTO NEXT WEEKEND. CONDITIONS WILL REMAIN DRY THROUGH THE EXTENDED
PERIOD...BUT TEMPERATURES WILL FALL BACK TO NORMAL...WITH COASTAL
HIGHS IN THE 60S AND INLAND HIGHS MAINLY IN THE 70S. WILL ALSO SEE
MARINE STRATUS BREACHING FURTHER INLAND THURSDAY AND FRIDAY. /27

&&

.AVIATION...VFR CONTINUES UNDER DRY AND STABLE CONDITIONS. ONLY
ISSUE WILL BE THE POCKETS OF LOW IFR STRATUS FOR COASTAL AREAS
AFTER 02Z...SIMILAR TO SAT NIGHT/SUN AM.

KPDX AND APPROACHES...DRY AND STABLE WITH VFR. NO ADVERSE WX
IMPACTS THROUGH MON.                               ROCKEY.
&&

.MARINE...NO CHANGES AS HIGH PRES REMAINS ANCHORED OVER NE PAC
WITH THERMAL LOW PRES SITS OVER NW CALIF AND SW OREGON. THIS
MAINTAINS EARLY SUMMER PATTERN OF NLY WINDS ON THE WATERS... WITH
STRONGEST IN AFTERNOONS/EVENINGS. OVERALL...SEAS 5 TO 7 FT... BUT
BIT HIGHER S OF CASCADE HEAD WHERE WINDS WILL CREATE CHOPPY AND
STEEP SEAS OF 8 TO 10 FT AT TIMES. CURRENT ADVISORIES REMAIN IN
EFFECT THROUGH MON NIGHT.                         ROCKEY.
&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...HEAT ADVISORY THROUGH MON EVENING FOR WILLAMETTE VALLEY.

WA...HEAT ADVISORY THROUGH MON EVENING FOR CLARK COUNTY IN SW WASH.

PZ...SMALL CRAFT ADVISORY FOR WINDS THROUGH MON NIGHT ON ALL WATERS.
     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS THROUGH MON NIGHT ON
            COASTAL WATERS FROM CASCADE HEAD TO FLORENCE.
&&

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.