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000
FXUS66 KPQR 062230
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
229 PM PST FRI DEC  6 2013

.SYNOPSIS...AN UPPER LEVEL DISTURBANCE AND A SURFACE LOW THAT WAS
ALONG THE OREGON COAST WILL MOVE SOUTH OF OUR FORECAST AREA TONIGHT
WITH DECREASING SNOW. STRONG OFFSHORE FLOW WILL GIVE WINDY CONDITIONS
THROUGH THE GORGE INTO SATURDAY WITH LOW WIND CHILLS ESPECIALLY IN
THE CASCADES AND THE GORGE. MUCH COLDER AIR SETTLES OVER THE FORECAST
AREA TONIGHT IN THE WAKE OF THIS DISTURBANCE AND LINGERS THROUGH THE
WEEKEND. A SLOW MODERATION BEGINS TO OCCUR NEXT WEEK...FOLLOWED BY A
TRANSITION TO MILDER AND WETTER CONDITIONS THE LATTER HALF OF NEXT
WEEK. THIS TRANSITION COULD START ICY FOR MANY INLAND AREAS LATER
TUESDAY INTO WEDNESDAY WITH COLD AIR IN PLACE.
&&

.SHORT TERM...TONIGHT THROUGH MONDAY...A LOW ALONG THE COAST THAT
SPREAD SNOW ACROSS MUCH OF SOUTHWEST WASHINGTON AND NORTHWEST OREGON
TODAY...WILL MOVE SOUTH OF THE AREA TONIGHT WITH DECREASING SNOW. AND
CLOUDS. WILL STILL HAVE A FEW WINTER WEATHER ADVISORIES IN THE
SOUTHERN ZONES THIS EVENING. THERE WILL BE SOME LINGER SNOW SHOWERS
INTO EARLY SATURDAY IN OUR SOUTHERN CASCADE ZONES.

THE HEAVIEST SNOW HAS BEEN IN THE SOUTH WILLAMETTE VALLEY...BUT
DECENT AMOUNTS IN THE COASTAL MOUNTAINS AND EVEN ALONG THE COAST.
THE PORTLAND METRO AREA HAS HAD MOSTLY LESS THAN AN INCH BUT THE
ROADS WERE ICY THIS MORNING AND JAMMED UP TRAFFIC.

HAVE SLOWED DOWN THE CLEARING A BIT OVERNIGHT AS THE MODELS SHOW
CLOUDS LINGERING FOR A WHILE. THIS MAY AFFECT LOW TEMPS TONIGHT...
WHICH WILL BE VERY TRICKY. MOS GUIDANCE SHOWS LOW TEMPERATURES
SATURDAY MORNING WILL BE LOWER THAN EVEN THOSE THURSDAY MORNING WHEN
WE SET A TON OF RECORDS. THE TWO OPPOSING COMPLICATIONS WILL BE HOW
LONG THE CLOUDS HANG ON VERSUS THE SNOW COVER THAT REMAINS FROM
TODAY. AREAS WHERE SNOW COVER REMAINS AND THE SKIES CLEAR HAVE A
DECENT CHANCE OF SEEING MORNING LOWS SATURDAY IN THE SINGLE DIGITS.
THUS MOS MAY BE TOO WARM. THIS WOULD MAKE THIS THE COLDEST WE HAVE
SEEN IN SOME TIME. FROM WHAT I COULD QUICKLY SEE...THE LAST SINGLE
DIGIT LOW AT PORTLAND AIRPORT WAS 1950 AND A COLDER SPOT LIKE
HILLSBORO WAS 1972.

IT LOOKS DRY AND COLD THROUGH THE REMAINDER OF THE WEEKEND. WITH LESS
CLOUDS...SUNDAY MORNING MAY EVEN BE COLDER THAN SATURDAY MORNING WITH
MORE AREAS DROPPING INTO THE SINGLE DIGITS.

THERE IS A SHORT WAVE DROPPING SOUTH WELL OFFSHORE SATURDAY NIGHT BUT
THIS LOOKS TOO FAR OFFSHORE TO AFFECT OUR AREA.

ON MONDAY WE STAY IN THE COLD BUT DRY NORTHERLY FLOW. TOLLESON

.LONG TERM...MONDAY NIGHT THROUGH FRIDAY. MID RANGE MODELS HAVE BEEN
CONSISTENT ON FORECASTING LIGHT PRECIPITATION MONDAY NIGHT INTO
TUESDAY MORNING AS A WEAK DISTURBANCE DROPS SOUTH ALONG THE WEST
COAST. MODELS SUGGEST WARMING AHEAD OF THE PRECIPITATION...BUT THINK
THE WELL ESTABLISHED ARCTIC AIR WILL BE MORE DIFFICULT TO WARM THAN
THE MODELS SUGGEST...AND AM CURRENTLY FORECASTING TEMPERATURES BELOW
GUIDANCE FOR MONDAY NIGHT AND TUESDAY. THEREFORE...FREEZING RAIN...
SNOW...RAIN...OR SOME MIX OF THE ABOVE IS POSSIBLE MONDAY NIGHT INTO
TUESDAY MORNING.

A WARM FRONT WILL CLIP THE NORTHWEST OREGON/SOUTHWEST WASHINGTON
TUESDAY NIGHT BEFORE A SERIES OF MOISTER AND MILDER FRONTS MOVE
ACROSS THE REGION. TEMPERATURES WILL WARM AND EXPECT SNOW LEVELS TO
RISE NEAR THE CASCADE PASS LEVELS WITH THESE SYSTEMS. DIFFERENCES
BETWEEN THE VARIOUS MODELS MAKE IT DIFFICULT TO HONE IN ON THE TIMING
OF THE BANDS OF PRECIPITATION...BUT GENERALLY EXPECT HEAVY RAIN AND
MOUNTAIN SNOW AT TIMES BETWEEN WEDNESDAY AND FRIDAY...AND GUSTY WINDS
ALONG THE COAST. HARTLEY
&&

.AVIATION...MVFR CONDITIONS WILL PERSIST FROM ABOUT CORVALLIS TO
EUGENE THROUGH THE AFTERNOON INTO THE EARLY EVENING HOURS WITH LIGHT
SNOW SHOWERS. FURTHER NORTH...MAINLY VFR CONDITIONS THIS AFTERNOON
AND TONIGHT. STRONG EAST WINDS WILL CONTINUE THROUGH THE COLUMBIA
RIVER GORGE AND ACROSS THE PORTLAND METRO AREA TONIGHT.

KPDX AND APPROACHES...VFR CONDITIONS EXPECTED THROUGH THE AFTERNOON
AND TONIGHT. STRONG EAST WINDS IN THE 25 TO 35 KT RANGE THROUGHOUT
THE DAY. TW
&&

.MARINE...EXPECT GUSTY E TO NE WINDS THIS EVENING AND TONIGHT BEFORE
WINDS SUBSIDE TOWARDS DAYBREAK. EXPECT RELATIVELY BENIGN WEATHER
SATURDAY THROUGH TUESDAY. A STRONGER LOW PRESSURE SYSTEM MAY IMPACT
THE REGION TOWARDS THE MIDDLE OF NEXT WEEK...BUT DECENT UNCERTAINTY
EXISTS IN THE TIMING AND STRENGTH OF THE WINDS. SOUTHERLY GALES
APPEAR AT LEAST POSSIBLE. /NEUMAN
&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WIND CHILL WARNING FROM 7 PM THIS EVENING TO NOON PST SATURDAY
     FOR CASCADES IN LANE COUNTY-NORTHERN OREGON CASCADES.

     WINTER WEATHER ADVISORY UNTIL 7 PM PST THIS EVENING FOR CASCADE
     FOOTHILLS IN LANE COUNTY-CENTRAL COAST RANGE OF WESTERN
     OREGON-CENTRAL OREGON COAST-CENTRAL WILLAMETTE VALLEY-
     NORTHERN OREGON CASCADE FOOTHILLS-SOUTH WILLAMETTE VALLEY.

     WIND ADVISORY UNTIL 6 AM PST SATURDAY FOR GREATER PORTLAND
     METRO AREA.

WA...WIND CHILL WARNING FROM 7 PM THIS EVENING TO NOON PST SATURDAY
     FOR SOUTH WASHINGTON CASCADES.

     WIND ADVISORY UNTIL 6 AM PST SATURDAY FOR GREATER VANCOUVER
     AREA.

PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 AM PST SATURDAY FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

&&

$$


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


INTERACT WITH US VIA SOCIAL MEDIA
    WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
    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.