Storm Warning 3, NWS Portland, OR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
940 AM PST FRI FEB 14 2014

.SYNOPSIS...A RATHER STRONG PACIFIC COLD FRONT WAS MOVING THROUGH
NORTHWEST OREGON WITH DECREASING RAIN AND WINDS. WILL BE BETWEEN
SYSTEMS THIS AFTERNOON AND THIS EVENING. THE BREAK IN WET WEATHER
WILL BE SHORT LIVED AS AN EVEN STRONGER STORM SYSTEM MOVES INTO THE
AREA SATURDAY WITH STRONG WINDS FOR THE COAST...HEAVY RAIN AND SOME
SNOW IN THE HIGHER CASCADES IN THE FAR NORTH. POSSIBLY THE WETTEST
STORM OF THIS SERIES WILL ARRIVE SUNDAY NIGHT AND MONDAY...WITH LOWER
SNOW LEVELS IN THE CASCADES AND MORE AREAS OF WIND. A MUCH COOLER AND
SHOWERY PATTERN WILL DEVELOP NEXT WEEK...WITH SNOW LEVELS LIKELY
DROPPING INTO AT LEAST THE CASCADE FOOTHILLS AND COASTAL MOUNTAINS.
&&

.SHORT TERM...TODAY THROUGH SUNDAY...THE NEXT FRONT IN THE CURRENT
SERIES WAS MOVING THROUGH OUR FORECAST AREA THIS MORNING...AND
NATIONAL WEATHER SERVICE DOPPLER RADAR SHOWS THAT IT IS TRYING TO
MOVE EAST OF EVEN LANE COUNTY A BIT FASTER THAN THE MODELS...AND HAVE
SPED THAT UP IN THE FORECAST FOR TODAY AND EASED BACK ON THE
PRECIPITATION AMOUNTS FOR THE REST OF THE DAY. WILL SEE SOME SHOWERS
TODAY ACROSS THE AREA...ESPECIALLY IN THE MOUNTAINS...BUT AMOUNTS DO
NOT LOOK VERY HIGH. WILL SEE THE SNOW LEVEL LOWER SOME TODAY...TRY TO
GET CLOSE TO PASS ELEVATIONS IN THE CASCADES...BUT AMOUNTS WILL BE
MODEST AND BELOW SNOW ADVISORY CRITERIA.

THE LULL WILL BE RATHER SHORT LIVED AS THE NEXT SYSTEM APPROACHES
TONIGHT. WILL LIKELY SEE SOME WARM FRONTAL PRECIPITATION START TO
SPREAD IN FROM THE SOUTHWEST LATE TONIGHT BUT THE MAIN EVENT WILL BE
SATURDAY AS THE MAIN OVERRUNNING PRECIPITATION SPREADS ONSHORE. IT
WILL AGAIN BE A WET SYSTEM WITH RATHER WARM SNOW LEVELS...GENERALLY
UP NEAR 6000 FEET OR HIGHER. PERHAPS AREAS NEAR THE SOUTH WASHINGTON
CASCADE CREST MIGHT HAVE A LITTLE LOWER SNOW LEVEL AND GET SOME SNOW
ACCUMULATION. THE MAIN STORY WILL BE RAIN AND WIND...AND THE
HYDROLOGY IS DISCUSSED BELOW.

THIS SYSTEM HAS STRONG 850 MB JET WITH IT...AND THE HIGH WIND WATCH
FOR THE COAST LOOKS REASONABLE. HAVE ADDED A BRIEF PERIOD TO THE
WATCH FOR THE COASTAL MOUNTAINS. THIS EVENT LOOKS TO BE CLOSE TO THE
STRENGTH OF THE ONE LAST TUESDAY NIGHT...BUT A LITTLE LESS.

THE COLD FRONT SWINGS THROUGH OUR AREA SATURDAY EVENING...WITH THE
WINDS AND RAIN DECREASING BEHIND THE FRONT. SNOW LEVELS DROP
DRAMATICALLY BEHIND THE FRONT SATURDAY NIGHT AND SUNDAY...TO WELL
BELOW THE PASSES AND LIKELY INTO THE COASTAL MOUNTAINS AND THE
CASCADE FOOTHILLS. THERE APPEARS TO BE ENOUGH ONSHORE FLOW TO SEE
SOME PRETTY GOOD SNOW ACCUMULATIONS SATURDAY NIGHT AND SUNDAY...
POSSIBLY EXCEEDING ADVISORY THRESHOLDS.

THERE IS ANOTHER SLOWLY MOVING WET FRONT SPREADING DOWN FROM THE
NORTHWEST LATE SUNDAY...FOR MORE RAIN...WIND...AND HEAVY MOUNTAIN
SNOW AS SNOW LEVELS STAY RELATIVELY LOW FOR THIS SYSTEM. TOLLESON

.HYDROLOGY...WE HAD 1 TO 1.5 INCH RAIN AMOUNTS ACROSS THE SOUTHERN
PART OF OUR OREGON ZONES...AND THERE ARE SEVERAL RIVERS THAT MAY
REACH FLOOD STAGE. HAVE ISSUED A WARNING FOR THE MARYS RIVER... BUT
THE SIUSLAW AND LUCKIAMUTE RIVER MAY ALSO FLOOD. RAIN HAS DECREASED A
BIT EARLIER THAN PREVIOUSLY THOUGHT...SO THOSE MAY BE ONLY ONES THIS
TIME AROUND. THE NEXT SYSTEM FOR SATURDAY STILL LOOKS WET... AND WILL
LIKELY STILL HAVE MORE FLOODING. THEN WE HAVE ANOTHER WET SYSTEM
SUNDAY NIGHT AND MONDAY THAT COULD BRING ANOTHER SURGE OF POSSIBLE
FLOODING. WILL BE CONTINUING THE FLOOD WATCH THROUGH THE WEEKEND.
TOLLESON
&&

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...SUNDAY NIGHT
THROUGH THURSDAY...A BROAD UPPER LEVEL LOW WILL SET UP IN THE GULF OF
ALASKA THIS WEEKEND...USHERING IN A SERIES OF SHORTWAVES AND FRONTAL
SYSTEMS UNDER MOIST ONSHORE FLOW THROUGH NEXT WEEK. AFTER A SOGGY
WEEKEND...MODELS ARE SHOWING LITTLE RELIEF IN PRECIPITATION. THE LAST
BIT OF A STATIONARY FRONT WILL SAG SOUTH ACROSS THE FORECAST AREA
LATE SUNDAY...DRAGGING THE HEAVIEST PRECIPITATION ACROSS THE CENTRAL
OR COAST RANGE...CENTRAL AND SOUTH WILLAMETTE VALLEY...AND LANE
COUNTY CASCADES. THIS FRONT STALLS OVER THE REGION INTO MONDAY
MORNING...POSSIBLY INTO MONDAY EVENING. MODELS ARE COMING TOGETHER
WITH THE NEXT FRONT ARRIVING MIDDAY TUESDAY... FOLLOWED BY YET
ANOTHER SYSTEM WEDNESDAY. AT THIS TIME...THE STUBBORN UPPER LOW OVER
ALASKA BEGINS TO FILL/WEAKEN AND SLIDE SOUTHWARD. THIS WILL ALLOW A
COOLER AIR MASS TO SETUP OVER THE PACIFIC NORTHWEST LATE IN THE WEEK.
SHOWERS CONTINUE INTO THURSDAY...AS COOLER TEMPERATURES RETURN. /27
&&

.AVIATION...UNSTABLE ONSHORE FLOW WILL LEAD TO GENERALLY VFR
CONDITIONS WITH ONLY OCCASIONAL MVFR CONDITIONS. THERE IS A CHANCE
CONDITIONS MAY DETERIORATE INTO IFR TONIGHT FOR NORTHERN TAF SITES AS
HIGH PRESSURE TEMPORARILY MOVES INTO THE REGION...BUT CONFIDENCE IS
LOW. EXPECT RAIN TO MOVE INTO THE REGION FROM THE SOUTHWEST AROUND
12Z SATURDAY...WITH MVFR CIGS LIKELY INCREASING AFTER THIS POINT.

KPDX AND APPROACHES...EXPECT MAINLY VFR CONDITIONS WITH BRIEF PERIODS
OF MVFR CONDITIONS THROUGH 18Z SATURDAY. /NEUMAN
&&

.MARINE...INHERITED FORECAST APPEARS ON TRACK. PREVIOUS DISCUSSION
BELOW...

A SECOND AND EVEN STRONGER FRONTAL SYSTEM IS EXPECTED TO MOVE ACROSS
THE WATERS SAT AFTERNOON/EVENING. LATEST GUIDANCE SHOWS THE POTENTIAL
FOR SOUTH WIND GUSTS TO 55 KT WITHIN THE COASTAL JET AHEAD OF THIS
FRONT. HAVE EXTENDED THE STORM WATCH NORTH BUT CONFIDENCE IS NOT AS
STRONG AS IN THE SOUTHERN WATERS GIVEN THE FACT THAT THE FLOW IS
OFFSHORE AHEAD OF THE OCCLUDING SURFACE LOW THAT PASSES BY NORTH AND
WEST. THAT SAID THERE WILL BE A SHORTER PERIOD OF TIME IN THE
AFTERNOON WHERE THE GRADIENT LOOKS TO OPEN UP ENOUGH TO SUPPORT
LIKELY GALES AND POSSIBLE STORMS...MOST LIKELY CLOSER TO SHORE.

CHAOTIC SEAS WILL BE BUILDING WITH THIS SECOND STORM...LIKELY TO
REACH 15-20 FEET BY LATER SAT NIGHT. ADDITIONALLY THIS SYSTEM WILL
HAVE A GOOD DYNAMIC FETCH AS IT PUSHES ONSHORE...SO THE SWELL BEHIND
IT MAY REACH THE 20-25 FT RANGE LATER SUNDAY INTO EARLY MONDAY.

WHILE THE LARGE SWELL IS PUSHING IN...A MORE CLASSIC LOOKING COASTAL
JET IS SETTING UP FOR YET ANOTHER FRONT ON SUNDAY ON PAR WITH THE
STRENGTH OF THE SATURDAY SYSTEM WITH STORM FORCE WINDS LIKELY. THIS
IS THE LAST OF THE STRONG SYSTEMS...BUT CONTINUED WESTERLY FLOW WILL
GUIDE WEAKER SYSTEMS THROUGH THE WATERS NEXT WEEK. 20 FT SEAS EASE
LATER MONDAY BUT THESE SYSTEMS WILL KEEP SEAS ELEVATED WELL ABOVE 10
FT THROUGH AT LEAST THURSDAY. /KMD
&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...FLOOD WATCH THROUGH SUNDAY AFTERNOON FOR CASCADE FOOTHILLS IN
     LANE COUNTY-CASCADES IN LANE COUNTY-CENTRAL COAST RANGE OF
     WESTERN OREGON-CENTRAL OREGON COAST-CENTRAL WILLAMETTE
     VALLEY-COAST RANGE OF NORTHWEST OREGON-GREATER PORTLAND
     METRO AREA-NORTH OREGON COAST-NORTHERN OREGON CASCADE
     FOOTHILLS-NORTHERN OREGON CASCADES-SOUTH WILLAMETTE VALLEY.

     HIGH WIND WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY
     EVENING FOR CENTRAL COAST RANGE OF WESTERN OREGON-COAST RANGE
     OF NORTHWEST OREGON.

     HIGH WIND WATCH FROM SATURDAY MORNING THROUGH SATURDAY
     AFTERNOON FOR NORTH OREGON COAST.

     HIGH WIND WATCH FROM SATURDAY MORNING THROUGH SATURDAY
     AFTERNOON FOR CENTRAL OREGON COAST.

WA...FLOOD WATCH THROUGH SUNDAY AFTERNOON FOR SOUTH WASHINGTON COAST.

     HIGH WIND WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY
     EVENING FOR WILLAPA HILLS.

     HIGH WIND WATCH FROM SATURDAY MORNING THROUGH SATURDAY
     AFTERNOON FOR SOUTH WASHINGTON COAST.

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

     STORM WATCH FROM SATURDAY MORNING THROUGH SATURDAY EVENING FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 AM PST
     SATURDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
     FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 7 AM
     PST SATURDAY.

&&

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.