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000
FXUS66 KPQR 241001
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
300 AM PDT FRI MAY 24 2013

.SYNOPSIS...A COLD UPPER LEVEL CLOSED LOW IS CENTERED OVER WESTERN
WASHINGTON THIS MORNING. A SHORTWAVE ROTATING AROUND THE LOW BROUGHT
WIDESPREAD PRECIPITATION TO THE REGION YESTERDAY AND OVERNIGHT.
PRECIPITATION IS NOW TAPERING OFF...BUT EXPECT SHOWERS TO CONTINUE
MUCH OF THE DAY AS THE AIR MASS REMAINS RELATIVELY UNSTABLE WHILE THE
LOW SLOWLY MOVES TOWARD THE NORTHEAST. A BROAD AREA OF UPPER LEVEL
TROUGHING WILL REMAIN IN PLACE THIS WEEKEND TO KEEP A CHANCE OF
SHOWERS OVER THE AREA. THE MOST ORGANIZED PRECIPITATION OVER THE
WEEKEND WILL LIKELY ACCOMPANY A SHORTWAVE MOVING THROUGH LATE
SATURDAY INTO EARLY SUNDAY...BUT PRECIP SHOULD REMAIN LIGHT. A MORE
ORGANIZED OF SYSTEM COULD BRING A BETTER SHOT OF RAIN MONDAY.
GENERALLY UNSETTLED WEATHER SHOULD CONTINUE FOR MUCH OF NEXT
WEEK...WITH PERIODIC CHANCES FOR LIGHT PRECIPITATION.
&&

.SHORT TERM...THE CLOSED LOW PRESSURE SYSTEM SITTING OVER THE PAC NW
FOR MUCH OF THE WEEK IS NOW CENTERED OVER WESTERN WASHINGTON. A WAVE
OF EMBEDDED ENERGY ROTATING AROUND THE LOW BROUGHT ENHANCED
PRECIPITATION TO MOST OF THE REGION DURING THE DAY YESTERDAY AND
THROUGH THE OVERNIGHT HOURS. SEVERAL SITES PICKED UP AN ADDITIONAL 1
TO 2 INCHES OF RAINFALL OVER THE PAST 24 HRS...MAINLY IN THE NORTHERN
PORTIONS OF THE FCST AREA. IT APPEARS THAT SEVERAL MORE DAILY RECORD
RAINFALL RECORDS WERE SET YESTERDAY. HOWEVER...THE LATEST RADAR
IMAGERY SHOWS THAT PRECIP INTENSITY IS DECREASING SIGNIFICANTLY THIS
MORNING AS THE UPPER LEVEL FORCING VISIBLE ON WATER VAPOR SATELLITE
IS NOW MOSTLY THROUGH THE REGION. EXPECT THE HEAVIEST SHOWERS TO
CONTINUE OVER THE NEXT FEW HOURS OVER THE S WASHINGTON AND N OREGON
CASCADES AS THE LAST OF THE SHORTWAVE ENERGY PUSHES EAST. THE UPPER
LOW WILL BEGIN TO SLOWLY PUSH OFF TO THE NE TODAY. AS WARMER AIR
MOVES IN ALOFT...THE INSTABILITY WILL BE DECREASING. EXPECT JUST
SOME LIGHT LOW TOPPED SHOWERS ACROSS THE REGION TODAY...WITH A FEW
BREAKS IN THE CLOUDS POSSIBLE LATER IN THE DAY. TEMPS SHOULD REBOUND
A BIT...WITH THE INTERIOR LOWLANDS GETTING BACK INTO THE 60S.

THE UPPER LOW WILL SETTLE OVER THE CANADIAN ROCKIES FOR THE
WEEKEND...WITH A BROAD UPPER LEVEL TROUGHING PATTERN OVER THE PAC NW.
EXPECT OFF AND ON SHOWER ACTIVITY MUCH OF THE WEEKEND. THE BEST
CHANCE AT ANY ORGANIZED PRECIPITATION APPEARS TO BE SAT NIGHT INTO
EARLY SUN...AS THE MODELS ALL SHOW A SHORTWAVE OR WEAK CLOSED LOW
PUSHING INTO THE PAC NW. TEMPS SHOULD CONTINUE TO REBOUND...AS WE GET
MORE SUNBREAKS AND THE AIRMASS MODERATES. INLAND SITES SHOULD GET
INTO THE MID 60S ON BOTH SAT AND SUN.

ANOTHER MORE ORGANIZED SYSTEM IS BEING ADVERTISED ON MON. THERE IS
PLENTY OF MODEL UNCERTAINY WITH THIS SYSTEM...WITH SOME MODEL RUNS
STRETCHING THE UPPER LEVEL FORCING AND KEEPING THE BULK OF IT TO OUR
SOUTH. HOWEVER...IT APPEARS THAT WE WILL HAVE A DECENT SHOT AT
WIDESPREAD...ALBEIT LIGHT...PRECIPITATION. DECIDED TO GO WITH LIKELY
POPS LATER MON AS MOST MODELS ARE BRINGING PRECIP INTO OUR FCST AREA.
PYLE

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
WESTERLY FLOW ALOFT LIKELY TO BE PERSIST THROUGH THE EARLY PART OF
THE WEEK. THIS WILL KEEP REGION UNDER A PERSISTENT CHANCE FOR RAIN AS
A SERIES OF SHORTWAVES MOVES THROUGH. THE WESTERLY FLOW OFF THE
PACIFIC WILL KEEP TEMPERATURES MODERATED...LIKELY A LITTLE BELOW
SEASONAL AVERAGES. MODELS TEND TO DIVERGE SOME LATE IN THE WEEK WITH
GFS AND CANADIAN CUTTING OFF AN UPPER LOW OFFSHORE. BOTTOM LINE
THOUGH IS FOR A CONTINUATION CHANCE OF RAIN.
&&

.AVIATION...WEAK LOW PRESSURE LINGERING OFFSHORE FROM ASTORIA
CONTINUES TO SPREAD AREAS OF -RA/-DZ ONSHORE. HOWEVER IT APPEARS
THE HEAVIEST AND STEADIEST PRECIPITATION HAS SHIFTED EAST INTO THE
CASCADES. MOIST AIR MASS AND WEAK FLOW WILL PROBABLY CAUSE SOME
IFR/LOW MVFR TO DEVELOP COAST AND INLAND BY SUNRISE. HOWEVER
INCREASING S-SW FLOW SHOULD PUSH CIGS ABOVE 2000 FT BY MIDDAY.
THIS AFTERNOON AND EVENING WILL BE MAINLY VFR WITH SOME MVFR IN
SCATTERED SHOWERS.

KPDX AND APPROACHES...WEAK FLOW AND MOIST AIR MASS WILL LIKELY
RESULT IN CIGS BELOW 1500 FT THROUGH 16Z...WITH SOME AREAS OF IFR
EMBEDDED WITHIN. AREAS -RA/-DZ CONTINUING THROUGH THIS MORNING.
INCREASING S-SW FLOW SHOULD RAISE CIGS ABOVE 2000 FT BY MIDDAY
WITH VFR BUT SCATTERED SHOWERS THIS AFTERNOON.WEAGLE

&&

.MARINE...SEAS HOVERING AROUND 10 FT IN THE OUTER WATERS AND 6 TO
8 FT IN THE INNER WATERS EARLY THIS MORNING. THE 10 FT SEAS SHOULD
BE SHORT-LIVED AS LOW PRES OFF ASTORIA WEAKENS AND NW FETCH DIES
DOWN. OPTED AGAINST SCA FOR SEAS AS THEY SHOULD BE BELOW 10 FT AT
ALL BUOYS BY SUNRISE. SEAS WILL CONTINUE TO SUBSIDE TODAY...
REMAINING AROUND 6 FT THROUGH THE WEEKEND.

SOME GUSTS TO 20 KT REPORTED IN MAINLY THE SOUTHERN WATERS SHOULD
EASE TODAY/TONIGHT AS THE LOW PRES SYSTEM WEAKENS AND WEAK HIGH
PRES BUILDS OVER THE WATERS. A WEAK LOW PRESSURE SYSTEM WILL MOVE
ACROSS THE OREGON WATERS LATE SAT/EARLY SUN...BUT WINDS SHOULD
GENERALLY STAY BELOW 25 KT. A MORE ORGANIZED SYSTEM IS POSSIBLE
FOR MON WHICH COULD PRODUCE A BRIEF COASTAL JET FOR GUSTS 30 TO
35 KT...BUT THIS DEPENDS ON THE TRACK. THERE IS STILL SOME
POSSIBILITY THIS SYSTEM COULD FOCUS MORE ON SRN OREGON AND NRN
CALIFORNIA THAN OUR WATERS.

MORNING EBBS REMAIN VERY STRONG DUE TO THE FULL MOON...SO EXPECT
ROUGH BAR CONDITIONS THE NEXT COUPLE MORNINGS.WEAGLE

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 8 AM
     THIS MORNING AND AGAIN FROM 4 AM TO 8 AM SATURDAY.


&&

$$

MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND

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.