Funnel Clouds in Oregon, September 17, 2015

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
945 AM PDT THU SEP 17 2015

.SYNOPSIS...A DECENT WEATHER SYSTEM BROUGHT SOME GOOD RAIN AMOUNTS TO
SOUTHWEST WASHINGTON AND NORTHWEST OREGON LATE LAST NIGHT AND THIS
MORNING...AND WAS MOVING THROUGH THE AREA TODAY WITH OCCASIONAL
SHOWERS. THE SYSTEM WILL BE EAST OF THE AREA THIS EVENING WITH JUST
SOME RESIDUAL SHOWERS MAINLY NEAR THE CASCADES THIS EVENING. FLAT
WEST TO NORTHWEST FLOW ALOFT WILL TAKE HOLD TONIGHT AND FRIDAY FOR
MOSTLY DRY WEATHER...EXCEPT FOR SOME SPRINKLES POSSIBLE NEAR THE
NORTH COASTAL AREAS AS VERY WEAK UPPER DISTURBANCES MOVE THROUGH. A
WEAK UPPER RIDGE WILL BE OVER THE AREA SATURDAY FOR MORE DRY AND
SLIGHTLY WARMER WEATHER BUT CONTINUED SMALL CHANCES OF SPRINKLES NEAR
THE NORTH COAST. LOOK FOR COOL NIGHTS THE NEXT FEW NIGHTS. ANOTHER
WEAK FRONT IS POSSIBLE LATE IN THE WEEKEND OR EARLY NEXT WEEK WHICH
COULD BRING SOME LIGHT RAIN.
&&

.SHORT TERM...A DECENT SYSTEM MOVED ONSHORE LATE LAST NIGHT AND THIS
MORNING WITH DECENT RAINFALL AMOUNTS...A QUARTER TO A HALF AN INCH OR
HIGHER IN THE VALLEYS...A QUARTER TO 0.75 INCH ALONG THE COAST...AND
UP TO AROUND AN INCH IN SOME OF THE HIGHER ELEVATIONS. THE MAIN UPPER
LEVEL SYSTEM IS MOVING EAST BUT A FAIR AMOUNT OF SHOWERS WILL
CONTINUE ESPECIALLY FROM THE COAST RANGE TO THE CASCADES THROUGH THE
AFTERNOON. THE SYSTEM WILL BE WELL EAST OF THE AREA THIS EVENING WITH
JUST SOME RESIDUAL SHOWERS NEAR THE CASCADES.

WEST TO NORTHWEST FLOW ALOFT WILL SLIGHTLY HIGHER 500 MB HEIGHTS WILL
SPREAD IN FRIDAY NIGHT AND SATURDAY. EXPECT SOME RESIDUAL CLOUDS
AROUND...SOME LOCAL FOG DEVELOPING LATER THURSDAY NIGHT AND FRIDAY
MORNING DUE TO RADIATION AND DAMP GROUND. THERE ARE A COUPLE A VERY
WEAK DISTURBANCES PASSING THROUGH IN THE FLOW FRIDAY THAT MAY GIVE
SOME SPRINKLES TO THE NORTH COASTAL AREAS...THE REMAINDER OF THE AREA
WILL BE DRY AND A BIT WARMER FRIDAY WITH A BIT MORE SUNSHINE THAN THE
LAST COUPLE OF DAYS.

THE UPPER HEIGHTS BUILD TO NEARLY 580 DM SATURDAY...SO LOOK FOR A BIT
MORE WARMING IN THE AFTERNOON INLAND...PERHAPS MID 70S...AFTER
ANOTHER COOL START IN THE MORNING. LOOK FOR SOME MORE AREAS OF
MORNING FOG AS WELL. MOST OF THE AREA WILL BE DRY...BUT WILL KEEP
SOME LOW POPS ALONG THE NORTH COAST AS THE MODELS CONTINUE TO SHOW A
WEAK BOUNDARY NEAR THE AREA. TOLLESON

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
SUNDAY NIGHT THROUGH WEDNESDAY. FLOW REMAINS FAIRLY ZONAL WITH A
BROAD TROUGH OVER THE PACNW THROUGH THE EXTENDED PERIOD. SHORTWAVES
RIDING DOWN THE BASE OF THIS UPPER-LEVEL TROUGH MAY CLIP OUR
SOUTHWEST WASHINGTON ZONES AND PERHAPS THE FAR NORTHERN OREGON COAST
RANGE AND CASCADES SUNDAY NIGHT BRINGING A SLIGHT CHANCE FOR SHOWERS
OR RAIN WHICH WILL CARRY INTO MONDAY FOR THE COAST RANGE AND
CASCADES. WEAK UPPER LEVEL TROUGH REMAINS OVER THE AREA TUESDAY BUT
SKIES SHOULD CLEAR AS THERMAL LOW PRESSURE MOVES INLAND. ANOTHER
SYSTEM APPROACHES LATE WEDNESDAY OR THURSDAY...BRINGING ANOTHER SHOT
FOR RAIN MIDWEEK. BOWEN/MCCOY
&&

.AVIATION...SHOWERS WILL CONTINUE TODAY AS AN UPPER LEVEL TROUGH
MOVES ACROSS THE REGION. ACROSS NW OREGON THIS MORNING CONDITIONS
WERE AM IX OF VFR AND MVFR CONDITIONS...WITH THE MVFR CIGS MOST
WIDESPREAD INLAND. EXPECT A MIX OF MVFR AND VFR TODAY...BUT WITH A
TREND TOWARDS PREDOMINANTLY VFR CONDITIONS TODAY AFTER 18Z.

PATCHY FOG DEVELOPING LATE TONIGHT COULD BRING IFR CIGS AND VSBY TO
THE COAST AND PORTIONS OF THE INTERIOR VALLEY AFTER 06Z TONIGHT.

KPDX AND APPROACHES...VFR CONDITIONS TODAY WILL BE TEMPORARILY
INTERRUPTED BY PERIODS OF MVFR CIGS AND SHOWERS THROUGH 20Z. AFTER20Z
VFR CONDITIONS SHOULD CONTINUE UNINTERRUPTED THROUGH AT LEAST 06Z
TONIGHT.THERE IS A CHANCE OF SEEING PATCHY FOG DEVELOPING OVERNIGHT
BRINGING IFR CIGS AND VISIBILITIES AFTER 06Z.
&&

.MARINE...BENIGN WEATHER EXPECTED THROUGH THE END OF THE WEEK
WEEKEND. IN GENERAL...EXPECT WINDS LESS 15 KT OR LESS WITH SEAS IN
THE 5 TO 6 FT RANGE THROUGH SUNDAY. THE NEXT THREAT FOR ADVISORY
WINDS LOOKS TO OCCUR EARLY NEXT WEEK.
&&

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

&&

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.