000 
FXUS66 KPQR 142217
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
300 PM PDT SAT JUL 14 2007

.SYNOPSIS...A STRONG RIDGE OF HIGH PRESSURE WILL REMAIN OVER THE
INTERIOR WESTERN STATES THROUGH THE WEEKEND WITH AN UPPER LEVEL LOW
OVER THE NORTHEAST PACIFIC. A WEAK PACIFIC FRONT WAS OFF THE COAST
THIS AFTERNOON AND WILL BRUSH MAINLY THE COASTAL AREAS TONIGHT AND
SUNDAY. PIECES OF THE OFFSHORE LOW MAY AFFECT SOUTHWEST WASHINGTON
AND NORTHWEST OREGON AT TIMES DURING THE MIDDLE OF NEXT WEEK.
&&

.SHORT TERM...A RATHER STRONG UPPER LEVEL RIDGE REMAINED OVER THE
INTERIOR OF THE WESTERN U.S. THIS AFTERNOON...WITH AN UPPER LOW
CENTERED AROUND 44N/143W IN THE NORTHEAST PACIFIC. A WEAK PACIFIC
FRONT OUT AHEAD OF THE LOW WAS INSIDE 130W THIS AFTERNOON AND MAKING
SLOW PROGRESS TOWARD THE COAST. THE RESULTANT SOUTHERLY FLOW OVER OUR
AREA CONTINUES TO RESULT IN SOME MID AND HIGHER LEVEL CLOUDS OVER THE
FORECAST AREA. THE NATIONAL WEATHER SERVICE DOPPLER RADAR IS
DETECTING SOME WEAK ECHOES BUT CLOUD HEIGHT OBSERVATIONS SUGGEST NONE
OF THIS IS LIKELY REACHING THE GROUND. THE MODELS DO SHOW A LITTLE
INSTABILITY OVER THE HIGHER CASCADES THIS AFTERNOON AND EVENING IN
THE SOUTHERLY FLOW...BUT THIS IS TEMPERED A BIT BY THE ONSHORE FLOW
WITH THE THERMAL TROUGH REMAINING TO THE EAST OF THE CASCADES. WILL
KEEP THE SLIGHT CHANCE FOR THUNDERSTORMS OVER THE CASCADES. THE
OFFSHORE FRONT BEGINS AFFECTING THE COAST TONIGHT...THEN LIFTS NORTH
SUNDAY BEFORE GETTING VERY FAR INLAND. MAIN EFFECT INLAND WILL BE
SOME MORNING CLOUDS SUNDAY AND A BIT COOLER TEMPERATURES. ON MONDAY
NOT A LOT OF CHANGE AS THERE WILL PROBABLY BE SOME MORNING CLOUDS
INLAND THROUGH COASTAL GAPS AGAIN...BUT SOUTHERLY FLOW INCREASES
AGAIN AHEAD OF THE OFFSHORE LOW AS THE OFFSHORE LOW RELOADS AND
INTENSIFIES. RECENT MODEL RUNS INDICATE THAT WE COULD START SEEING A
FEW SHOWERS AT LEAST AROUND THE MOUNTAINS ON TUESDAY AS THE OFFSHORE
LOW APPROACHES. TOLLESON
&&

.LONG TERM...THE MEDIUM RANGE MODELS ARE IN REASONABLE AGREEMENT
SHOWING THE OFFSHORE LOW DIGGING DOWN THE COAST AND THEN SWINGING
ONSHORE DURING THE EARLY PART OF THE EXTENDED PERIOD. THIS COULD
BRING A FEW SHOWERS TO OUR AREA. HAVE EASED INTO THIS SCENARIO IN THE
GRIDS FOR NOW. SHOULD DRY OUT FOR THE END OF THE WEEK THOUGH STILL
SOME ONSHORE FLOW IN SOUTHWEST FLOW ALOFT WITH 500 MB HEIGHTS NEAR
580 DM. FAIR AMOUNT OF SPREAD IN THE ENSEMBLES BY NEXT WEEKEND SO
WILL STAY NEAR CLIMATOLOGY FOR NOW. TOLLESON
&&

.AVIATION...VFR CONDITIONS PREVAILING INLAND TONIGHT INTO SUN
MORNING. APPEARS A CLOUD DECK AROUND 4000 FT ARRIVES SUN MORNING AS A
PACIFIC FRONT BRUSHES THE COAST. THE COAST WILL LIKELY RECEIVE MVFR
CIGS ALONG WITH SOME SHOWERS TONIGHT. ARRIVAL OF LOWER CIG EXPECTED
ABOUT 06Z RIGHT ALONG THE CENTRAL COAST AND A LITTLE LATER UP NORTH.
HOWEVER IFR STRATUS HAS BEEN SKIRTING RIGHT ALONG THE COASTLINE
THROUGH THE DAY AND MAY CONTINUE INTO THE EVENING. THOUGH EXPECT IT
TO BECOME LESS OF A THREAT AS THE FRONT NEARS...MIXING UP THE LOWER
LAYER.
&&

.MARINE...A PACIFIC FRONT WILL CONTINUE APPROACH THE WATERS TONIGHT
AND BRUSH THE COASTAL WATERS LATE TONIGHT AND SUN MORNING. WINDS WILL
GET CLOSE TO SMALL CRAFT LATER TONIGHT AND EARLY SUNDAY. SEAS WILL
REMAIN BELOW 10 FEET.
&&

.PQR WATCHES/WARNINGS/ADVISORIES...
WA/OR...NONE.

&&

.PRELIMINARY POINT POPS (PROBABILITY OF MEASURABLE PRECIPITATION)
AST 33-1-2   PDX 11---1   SLE 11---1   EUG 11--11
$$

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.