Area Forecast Discussion
Issued by NWS Portland, OR

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FXUS66 KPQR 020500
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
900 PM PST SUN MAR 1 2015

.SYNOPSIS...A WEAK COLD FRONT WILL BRING INCREASING CLOUDS AND
A CHANCE FOR RAIN AND MOUNTAIN SNOW TONIGHT AND EARLY MONDAY. WITH
THE BRUNT OF THIS SYSTEM TRACKING OFFSHORE THE BEST CHANCES FOR
PRECIPITATION WILL BE NEAR THE COAST. THIS SYSTEM WILL BE A FAST
MOVER...AND SOME CLEARING IS EXPECTED MONDAY AFTERNOON. THE UPPER
LEVEL RIDGE WHICH HAS BEEN SO DOMINANT THIS WINTER IS THEN EXPECTED
TO RETURN...LIKELY LEADING TO DRY WEATHER FOR THE REST OF THE WEEK.

&&

.SHORT TERM...SATELLITE IMAGERY SHOWED A SHORTWAVE DROPPING QUICKLY
S DOWN THE WA AND N OREGON COASTLINE THIS EVENING. RADAR SHOWED THE
MAIN AREA OF RAIN OFF THE COAST...BUT SOME LIGHT RAIN HAD MOVED
INLAND OVER WESTRN WA AND INTO THE N OREGON COAST RANGE. AS THE
SYSTEM DRIVES S OVERNIGHT WILL BUMP POPS ALONG THE COAST UP TO
CATEGORICAL...BUT FURTHER INLAND WILL LEAVE POPS MAINLY IN THE
CHANCE TO SLIGHT CHANCE CATEGORY AS THE QUICK MOVEMENT AND BEST
DYNAMICS OFF THE COAST SUGGEST NOT A LOT OF PRECPITATION PUSHING
INLAND.

REMAINDER OF SHORT TERM DISCUSSION UNCHANGED...
NORTHERLY FLOW WILL GENERALLY DRY THINGS OUT QUICKLY BEHIND THE FRONT
MONDAY. HOWEVER THE NORTHERLY FLOW WILL NOT BE AS STRONG NOR AS DRY
AS IT WAS SATURDAY...SO CLOUDS MAY BE A LITTLE MORE SLUGGISH TO
CLEAR. ALSO THE FLOW ALOFT TAKES SOME TIME TO TURN ANTICYCLONIC WITH
SOME SREF MEMBERS AND THE 18Z NAM EVEN HINTING AT SOME SNOW SHOWERS
CONTINUING IN THE CASCADES INTO MON NIGHT. WILL HANDLE THIS WITH SOME
SILENT POPS AND A LITTLE BIT OF EXTRA SKY COVER IN THE HIGHER TERRAIN
FOR NOW. MODELS SHOW GOOD CONSENSUS THAT STRONG UPPER RIDGING WILL
REBUILD OVER THE REGION TUE/WED...BRINGING US BACK TO AN UNSEASONABLY
DRY REGIME.  WEAGLE

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS. WEDNESDAY
NIGHT THROUGH SUNDAY...THE MEAN UPPER RIDGE POSITION LINGERS WHERE
IT HAS BEEN MUCH OF THIS WINTER...OVER THE NE PACIFIC AND ALONG THE
WEST COAST. THIS SHOULD KEEP THE PACIFIC JET STREAM WELL TO OUR
NORTH...AS WELL AS ANY CHANCES OF SIGNIFICANT PRECIPITATION.
THEREFORE OUR FORECAST REMAINS DRY THROUGH NEXT WEEKEND. CONDITIONS
MAY BECOME INCREASINGLY FAVORABLE FOR FOG IN THE VALLEYS...AS MOST
GUIDANCE PUSHES THE UPPER RIDGE AXIS ONSHORE LATE IN THE WEEK.
OTHERWISE EXPECT A GRADUAL RETURN TO ABOVE NORMAL TEMPERATURES WHICH
MAY LAST INTO NEXT WEEKEND.WEAGLE

&&

.AVIATION...A WEAK FRONT DROPPING SOUTHWARD ALONG THE PACIFIC
NORTHWEST COAST WILL BRING MVFR CONDITIONS TO THE COAST TONIGHT
WHILE CONDITIONS WILL LIKELY REMAIN PREDOMINANTLY VFR ACROSS THE
INTERIOR THROUGH 06Z TUESDAY. THE STEADIEST RAIN WILL LIKELY
REMAIN ALONG THE COAST. THERE IS A CHANCE STEADIER RAIN COULD PUSH
INTO THE WILLAMETTE VALLEY TOWARDS 12Z MONDAY...ESPECIALLY
HILLSBORO AND PRODUCE MVFR FLIGHT CONDITIONS...BUT CONFIDENCE IS
LOW. IF THESE LOWER CLOUDS DEVELOP...THEY COULD BE SOMEWHAT SLOW
TO CLEAR...PROBABLY 18Z TO 21Z MONDAY.

KPDX AND APPROACHES...INCREASING LOW LEVEL MOISTURE ASSOCIATED
WITH A WEAK FRONT WILL RESULT IN LOWERING CEILINGS THROUGH ABOUT
12Z TO 15Z MONDAY. THERE IS A CHANCE MVFR CONDITIONS MAY DEVELOP
AROUND THIS TIME...BUT CONFIDENCE IS LOW. BUILDING HIGH PRESSURE
AND DAYTIME HEATING SHOULD RESULT IN RISING CIGS MONDAY
AFTERNOON. /NEUMAN

&&

.MARINE...HIGH PRESSURE OVER THE NORTHEAST PACIFIC WILL BE THE
DOMINANT WEATHER PLAYER THIS WEEK. HOWEVER...A WEAK FRONT IS
DROPPING SOUTHWARD ACROSS THE OUTER WATERS TONIGHT AND WILL BRING
GUSTY NORTH TO NORTHWEST WINDS OF 15 TO 25 KT TO THE OUTER WATERS
THROUGH MONDAY. WINDS SHOULD FIRST DROP OFF ACROSS THE NORTH IN
THE MORNING...AND FOLLOW ACROSS THE CENTRAL OREGON WATERS MONDAY
AFTERNOON. IN ADDITION...A REASONABLY GOOD SIZE FRESH SWELL WILL
LIKELY PRODUCE STEEP HAZARDOUS SEAS ACROSS THE OUTER
WATERS...ESPECIALLY BEYOND ABOUT 30 TO 40 NM OF THE COAST. EXPECT
A NORTHWEST SWELL TO TOP OUT IN THE 8 FT AT 8 SECOND RANGE. SEAS
SHOULD SUBSIDE LATE MONDAY MORNING.

OTHERWISE...HIGH PRESSURE LOOKS TO DOMINATE THE WEATHER INTO NEXT
WEEKEND WITH NO MAJOR WIND CONCERNS ON THE HORIZON AND SEAS WILL
LIKELY REMAIN WELL UNDER 10 FT INTO THE UPCOMING WEEKEND. /NEUMAN

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 9 AM PST MONDAY FOR WATERS
     FROM CAPE SHOALWATER WA TO CASCADE HEAD OR FROM 10 TO 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 9 AM PST MONDAY
     FOR WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR FROM
     10 TO 60 NM-WATERS FROM CASCADE HEAD TO FLORENCE OR FROM 10
     TO 60 NM.

     SMALL CRAFT ADVISORY FOR WINDS UNTIL 3 PM PST MONDAY FOR WATERS
     FROM CASCADE HEAD TO FLORENCE OR FROM 10 TO 60 NM.

&&

$$

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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