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000
FXUS66 KPQR 250343
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
843 PM PDT FRI MAY 24 2013

.SYNOPSIS...A PIECE OF THE LOW THAT BROUGHT COPIOUS RAIN TO SOUTHWEST
WASHINGTON AND NORTHWEST OREGON WILL REMAIN CENTERED ALONG THE
WASHINGTON COAST TONIGHT AND SATURDAY MORNING THEN MOVE OFF TO THE
NORTHEAST. THIS WILL BE FOLLOWED BY ANOTHER LOW DROPPING IN FROM THE
NORTHWEST AND OFF THE PACIFIC LATER SATURDAY AND SATURDAY NIGHT FOR
MORE PRECIPITATION. THIS LOW WILL LINGER IN THE AREA SUNDAY BEFORE
MOVING EAST SUNDAY NIGHT. THE NEXT DECENT FRONT APPEARS THAT IT WILL
MOVE INTO SOUTHWEST WASHINGTON AND NORTHWEST OREGON ON MEMORIAL DAY
MONDAY. A MOSTLY WESTERLY FLOW WILL KEEP THINGS UNSETTLED WITH SOME
PRECIPITATION AT TIMES NEXT WEEK.
&&

.SHORT TERM...DID GET SOME DECENT SHOWERS ACROSS THE NORTHERN PART OF
OUR FORECAST AREA THIS AFTERNOON AND EVENING. MODEL DATA SHOWED
INSTABILITY UP THROUGH 700 MB BUT IT WAS CAPPED AT 600 AND 500 MB...
THUS THE SHOWERS WERE STILL VIGOROUS BUT NOT DEEP ENOUGH TO PRODUCE
CHARGE SEPARATION AND ANY LIGHTNING. SHOWERS ARE MOSTLY MOVING INTO
THE CASCADES AND DECREASING THIS EVENING...AND SHOULD CONTINUE TO
DECREASE OVERNIGHT.

NEXT UP IS A LOW OR CIRCULATION CENTER THAT IS CENTERED AROUND
48N/133W AND HEADING SOUTHEAST TOWARD SOUTHWEST WASHINGTON AND
NORTHWEST OREGON. SHOULD SEE SOME INCREASE IN PRECIPITATION THROUGH
THE DAY SATURDAY FROM THE WEST...WITH A PEAK SATURDAY NIGHT AS THIS
LOW MOVES ONSHORE. THE LOW IS STILL OVERHEAD OR NEARBY MUCH OF
SUNDAY...SO WE SHOULD SEE A DECENT AMOUNT OF SHOWERS. THE AIR ALOFT
MAY GET COOL ENOUGH WE MIGHT TRIGGER A THUNDERSTORM OR TWO SUNDAY
AFTERNOON.

SHOWERS SHOULD DECREASE SUNDAY NIGHT AS THIS LOW MOVES OFF TO THE
EAST. THE NEXT MORE PROGRESSIVE AND ORGANIZED PACIFIC COLD FRONT IS
EXPECTED TO MOVE IN ON MEMORIAL DAY MONDAY FOR INCREASING RAIN. SNOW
LEVELS WILL BE 7000 TO 8000 FEET WITH THIS FRONT. TOLLESON

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
MODELS START OUT IN GOOD AGREEMENT DURING THE EXTENDED PERIOD MON
NIGHT AND TUE...WITH A TROUGH PUSHING INLAND OVER THE WEST COAST.
MOST OF THE ENERGY APPEARS HEADED S OF THE FORECAST AREA TOWARDS CA.
AS THE NORTHERN STREAM APPEARS TO REMAIN AN OPEN WAVE...WILL BOOST
POPS INTO LIKELY CATEGORY. MODELS DIVERGE SOME LATER IN THE WEEK...
BUT KEEP A COMMON THEME OF SHORTWAVES PUSHING IN IN A WESTERLY FLOW
ALOFT. WILL KEEP POPS RELATIVELY HIGH FOR A SYSTEM ON WED...BUT THEN
WILL DROP POPS OFF LATER IN THE WEEK AS UPPER HEIGHTS RISE.
&&

.AVIATION...A WEAK TROUGH WILL CONTINUE OVER THE AREA TONIGHT WITH A
FEW SHOWERS CONTINUING. SATURDAY MORNING A WEAK BUT FAIRLY MOIST
SYSTEM WILL NEAR THE COAST. CURRENT MODELS INDICATING MAIN FOCUS OF
THE PCPN IS TO THE SOUTH PORTION OF THE FCST AREA. FOR THE COAST...
MAINLY VFR TO START BUT MVFR BECOMING LIKELY. AN ORGANIZED BAND OF
SHOWERS EXTEND OFF THE COAST FROM AROUND NEWPORT GIVING IFR
CONDITIONS THERE. CONDITIONS MAY IMPROVE 05Z TO 07Z FROM IFR TO MVFR
AS THE BAND SHIFTS NORTH. INLAND AREAS...FEW SHOWERS AROUND THOUGH
VFR CONDITIONS PREVAILING THIS EVENING. CONDITIONS BECOMING MORE
STABLE OVERNIGHT PER MODEL SOUNDINGS TRAPPING LOWER LEVEL MOISTURE
FOR INCREASING CHANCES OF MVFR CIGS DEVELOPING AFTER 12Z. BUT BY 18Z
OR SO CONDITIONS GENERALLY VFR BUT TENDING TO MVFR LATE SAT AFTERNOON
OR EVENING AS THE NEXT FRONT APPROACHES.

KPDX AND APPROACHES...VFR WITH A FEW SHOWERS EXPECTED THROUGH THE
NIGHT. STATISTICAL GUIDANCE AND MODEL SOUNDINGS SPLIT ON MVFR IN THE
AREA SAT MORNING SO WILL NOT INCLUDE MVFR AT THIS TIME.
&&

.MARINE...SEAS WILL REMAIN AROUND 6 FT THROUGH SUN. ANOTHER WEAK
SYSTEM PUSHES INTO THE WATERS EARLY ON SATURDAY...PROVIDING BREEZY
WINDS BY SATURDAY AFTERNOON BUT WINDS ARE EXPECTED TO REMAIN BELOW 20
KT. A MORE ORGANIZED SYSTEM IS EXPECTED ON MONDAY 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 COLUMBIA RIVER BAR CONDITIONS THE NEXT COUPLE MORNINGS.
BURGESS/WEAGLE
&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM
     4 AM TO 8 AM PDT 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.