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AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
1000 AM PDT SUN JUL  5 2015

.SYNOPSIS...HOT WEATHER WILL CONTINUE OVER MOST OF THE REGION THROUGH
MIDWEEK AS A STRONG RIDGE OF HIGH PRESSURE ALOFT REMAINS OVER THE 
AREA.  A BRIEF COOL DOWN IS POSSIBLE TONIGHT AND MONDAY FOR THE 
EUGENE AREA AS A SOUTHWEST SURGE OF MARINE AIR PUSHES THROUGH THE 
ADJACENT COAST RANGE.  AN UPPER LOW OFF CALIFORNIA MAY DRIFT FAR 
ENOUGH NORTH TUE/WED TO BRING THUNDERSTORMS UP THE CASCADE CREST TO 
LANE COUNTY BY MIDWEEK. RELIEF FROM THE HEAT MAY COME LATER THIS 
WEEK AS THE UPPER RIDGE BREAKS DOWN ENOUGH TO ALLOW STRONGER ONSHORE 
FLOW.

&&

.SHORT TERM...TEMPS AT 9AM THIS MORNING ARE RUNNING 2 TO 4 DEGREES
ABOVE SAT AM READING...SO WE REMAIN ON TRACK TO BE A LITTLE WARMER
INLAND TODAY. THE STRONG UPPER LEVEL RIDGE OF HIGH PRESSURE REMAINS
ENTRENCHED OVER NE PACIFIC AND STRETCHES SOUTHWARD TO THE FOUR
CORNERS REGION.  NOT MUCH CHANGE EXPECTED THE NEXT FEW DAYS...SO THE
PROLONGED PERIOD OF HOT WEATHER WILL CONTINUE OVER MOST OF THE INLAND
AREA THROUGH WEDNESDAY WITH HIGH TEMPERATURES IN THE 90S. THE COAST
WILL REMAIN PLEASANT WITH TEMPERATURES IN THE 60S AND 70S.  

THE THERMAL LOW WILL MOVE OFFSHORE LATER TODAY AS HIGH PRESS BUILDS
BEHIND A WEAK DISTURBANCE MOVING THROUGH THE NORTHERN ROCKIES IN ID
AND MT THIS MORNING.  WITH THE THERMAL LOW PRESSURE MOVING OFF THE WA
COAST AND WEAK FLOW ALOFT...IT PROVIDES A GOOD SETUP FOR THE
DEVELOPMENT OF A SOUTHERLY SURGE OF MARINE AIR TO DEVELOP AND PUSH UP
THE COAST TONIGHT. DEPENDING ON HOW DEEP THIS PUSH OF MARINE AIR CAN
GET...IT HAS THE POTENTIAL TO BRING SOME COOLING TO THE CENTRAL COAST
RANGE AND PERHAPS INTO THE SOUTHERN WILLAMETTE VALLEY NEAR THE EUGENE
METRO AREA. AREAS FURTHER NORTH ARE A DIFFERENT STORY...AS IT IS
DOUBTFUL THE MARINE PUSH WILL BE STRONG ENOUGH TO AFFECT AREAS SALEM
NORTHWARD. THUS...HOT WEATHER EXPECTED TO CONTINUE A FEW MORE DAYS. 

ANOTHER FEATURE OF INTEREST IS AN UPPER LEVEL LOW PRESSURE THATS BEEN
NEARLY STATIONARY OFF THE CALIFORNIA COAST THE PAST COUPLE DAYS. AS
THIS SYSTEM EVENTUALLY MOVES EASTWARD LATER IN THE WEEK...IT MAY
BRING SOME MOISTURE NORTHWARD INTO THE LANE COUNTY CASCADES ON
TUES/WED.  THE MOISTURE AND ENERGY FROM THE UPPER LEVEL LOW MAY BRING
A SLIGHT CHANCE OF THUNDERSTORMS TO THE LANE COUNTY CASCADES MIDWEEK.
 TW
 
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
TUESDAY NIGHT THROUGH SATURDAY...REX BLOCK REMAINS IN PLACE THROUGH
MID-WEEK WITH CONTINUED HOT AND DRY WEATHER ACROSS THE AREA. MODELS
CONTINUE TO SUGGEST REX BLOCK OVER THE WEST COAST STARTS TO BREAK
DOWN LATER THIS WEEK AS AN UPPER-LEVEL TROUGH PUSHES THE RIDGE OF
HIGH PRESSURE OFF TO THE EAST. THERE IS STILL SOME DISAGREEMENT ON
WHEN THIS WILL ACTUALLY BREAK DOWN...BUT ENSEMBLES SUGGEST A GOOD
CHANCE THAT THE BLOCKING PATTERN BREAKS DOWN BY FRIDAY. THIS SHOULD
BRING TEMPERATURES DOWN SOME FOR FRIDAY AND SATURDAY WITH A CHANCE
FOR SOME CLOUD COVER AS WELL. THERE IS A SLIGHT CHANCE FOR A
THUNDERSTORM OR TWO LATER THIS WEEK IN THE LANE COUNTY CASCADES AS
THE UPPER-LEVEL TROUGH MOVES THROUGH...BUT ELSEWHERE LOOKS TO REMAIN
DRY INTO NEXT WEEKEND. -MCCOY

&&

.AVIATION...IFR STRATUS AND FOG DEVELOPED ALONG THE IMMEDIATE
COAST. CIGS ARE GENERALLY UNDER 800 FT WITH SOME LOCATIONS IN FOG
WITH VIS LESS THAN 1/2 MILE. THE STRATUS AND FOG SHOULD CLEAR BY
17Z SUNDAY.  A SOUTHERLY WIND REVERSAL WILL DEVELOP ALONG THE
COAST FROM SOUTH TO NORTH DURING THE DAY TODAY. THIS WILL BRING 
STRATUS WILL RETURN TO THE COAST BY LATE AFTERNOON ON THE CENTRAL
COAST AND TONIGHT FOR THE SOUTH WASHINGTON COAST. VFR CONDITIONS
PREVAIL INLAND THROUGH EARLY MONDAY.

KPDX AND APPROACHES...VFR WILL CONTINUE THROUGH EARLY MONDAY. /26

&&

.MARINE...THE PRESSURE GRADIENT WILL CONTINUE TO WEAKEN OVER THE
WATERS TODAY AS A THERMALLY INDUCED LOW MOVES OFFSHORE. THE
THERMAL LOW WILL EXPAND OFF OF THE OREGON COAST TODAY RESULTING
IN A SOUTHERLY WIND REVERSAL. SOUTHERLY WINDS WILL DEVELOP FIRST
FOR THE CENTRAL OREGON COAST IN THE AFTERNOON...THEN FOR THE
WASHINGTON COAST TONIGHT. A WEAK PRESSURE GRADIENT WILL CONTINUE
THROUGH AT LEAST WEDNESDAY KEEPING SURFACE WINDS LIGHT...LESS THAN
15 KT. THE THERMAL LOW WILL WEAKEN BY THURSDAY WITH W-NW WINDS
RETURNING.

SEAS WILL GRADUALLY SUBSIDE TODAY AND REMAIN BELOW 6 FEET THROUGH
THURSDAY. THE VERY STRONG MORNING EBB WILL LIKELY RESULT IN ROUGH
BAR CONDITIONS SO A SMALL CRAFT ADVISORY WILL BE ISSUED. /26

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...HEAT ADVISORY UNTIL MIDNIGHT PDT WEDNESDAY NIGHT FOR CENTRAL 
     COLUMBIA RIVER GORGE-CENTRAL WILLAMETTE VALLEY-GREATER 
     PORTLAND METRO AREA-LOWER COLUMBIA-NORTHERN OREGON CASCADE 
     FOOTHILLS-UPPER HOOD RIVER VALLEY-WESTERN COLUMBIA RIVER 
     GORGE.

     HEAT ADVISORY UNTIL 6 PM PDT THIS EVENING FOR CASCADE FOOTHILLS 
     IN LANE COUNTY-CENTRAL COAST RANGE OF WESTERN OREGON-SOUTH 
     WILLAMETTE VALLEY.

WA...HEAT ADVISORY UNTIL MIDNIGHT PDT WEDNESDAY NIGHT FOR CENTRAL 
     COLUMBIA RIVER GORGE-GREATER VANCOUVER AREA-I-5 CORRIDOR IN 
     COWLITZ COUNTY-SOUTH WASHINGTON CASCADE FOOTHILLS-WESTERN 
     COLUMBIA RIVER GORGE.

PZ...SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR IN EFFECT
     UNTIL 9 AM PDT THIS MORNING.

&&

$$

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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