Winter Storm Warning 3, NWS Seattle, WA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
207 PM PST FRI FEB 3 2006

.SYNOPSIS...A POWERFUL STORM SYSTEM WILL BRING HIGH WINDS TO THE
AREA OVERNIGHT INTO SATURDAY. THERE WILL ALSO BE INCREASING RAIN
OVER THE AREA OVERNIGHT...WITH THE SNOW LEVELS RISING TO NEAR 6000
FEET. A COLDER AIR MASS WILL THEN INVADE THE REGION DURING THE DAY
SATURDAY...WITH THE SNOW LEVEL PLUMMETING TO NEAR 2000 FEET. LOOK
FOR DECREASING SHOWERS SATURDAY NIGHT...WITH DRY WEATHER PREVAILING
OVER THE AREA SUNDAY AFTERNOON.

&&

.SHORT TERM...
THE SURFACE LOW ASSOCIATED WITH A POWERFUL STORM OFFSHORE WAS DOWN
TO 970 MB AT 18Z...NEARLY 10 MILLIBARS LOWER THAN WHAT THE GFS
PREDICTED FOR THIS TIME. THUS THE PROBABILITY OF DAMAGING WINDS WAS
INCREASING FOR THE CWA. IT APPEARED THAT THE STRONGEST WINDS ON THE
COAST AND OLYMPICS WILL OCCUR BETWEEN 06Z AND 12Z... AND OVER THE N
AND SW INTERIORS BETWEEN 10Z AND 18Z. ELSEWHERE...IT APPEARED THAT
THE STRONGEST WINDS WILL OCCUR DURING THE DAY SAT...WITH SPEEDS
DROPPING OFF LATER IN THE AFTERNOON. WILL INDICATE THIS IN THE NEXT
UPDATE TO THE NPW.

MEANWHILE...A PERIOD OF HEAVY RAIN WILL OCCUR OVER THE OLYMPIC
PENINSULA TONIGHT AS VERY STRONG SLY 850 MB WINDS SERVE TO ENHANCE
RAIN RATES OVER THE S FACING SLOPES OF THE OLYMPICS. A FLOOD WATCH
WAS ISSUED FOR THE RIVERS IN MASON...THURSTON...AND GRAYS HARBOR
COUNTIES FOR THE POTENTIAL OF FLOOD PRODUCING RAINS. OTHERWISE LOOK
FOR THE SNOW LEVELS TO RISE TO NEAR 6K FT ACROSS THE CWA AS THE
WMFNT MOVES ACROSS THE AREA THIS EVENING.

ON SAT...A COLDER AIR MASS WILL QUICKLY INVADE THE REGION BEHIND A
VIGOROUS CDFNT...WITH SNOW LEVELS PLUMMETING TO NEAR 2K FT.
ADDITIONALLY...INCREASED ONSHORE FLOW WILL RESULT IN PERIODS OF
MODERATE TO HEAVY SNOW IN THE CASCADES STARTING SAT AFTERNOON. BY
SUN...THE CASCADES COULD RECEIVE 10 TO 18 INCHES OF NEW SNOW WITH
THE HIGHER AMOUNTS OCCURRING WITHIN THE PGTSND CONVERGENCE ZONE OR
PSCZ.

THE PSCZ WILL LIKELY DEVELOP SAT EVENING OVER THE FAR N PGTSOUND
BEFORE MOVING SWD AND WEAKENING DURING THE NIGHT. SINCE THE AIR MASS
WILL BE QUITE COLD AT THIS POINT...WOULD NOT BE SURPRISED IF SNOW
SHOWERS FELL AS LOW AS 500 FOOT LEVEL WITH THE HEAVIER PRECIP.
ALSO WENT ON AHEAD AND MENTIONED A SLIGHT CHANCE OF THUNDERSTORMS
FOR THOSE AREAS WITHIN THE PSCZ AS THE AIR MASS APPEARED QUITE
UNSTABLE.

ON SUN...AN UPPER RIDGE WILL BEGIN BUILDING OVER THE PAC NW FOR A
DRYING TREND. THUS EXPECT A CHANCE OF SHOWERS OVER MAINLY THE
CASCADES SUN MORNING...WITH DRY WEATHER PREVAILING OVER THE ENTIRE
CWA SUN AFTERNOON.

.LONG RANGE...AN UPPER RIDGE WILL PROVIDE DRY WEATHER OVER THE PAC
NW THROUGH THE PERIOD.

&&

.AVIATION...LOWERING CIGS WITH RAIN ON THE COAST SPREADING INLAND
THIS EVENING. PRECIP CIGS AND VSBY PROBABLY WILL BE TYPICAL OF A
STRONG FRONT WITH AREAS OF MVFR WITH THE FRONT OVERNIGHT. BIG STORY
WILL BE THE WINDS TOMORROW...POSSIBLY THE STRONGEST WINDS OF THE
WINTER FOR MOST OF THE AIRPORTS.

&&

.MARINE...A ONE TWO PUNCH FIRST OF SOUTHERLY WINDS AND THEN FOR THE
COAST AND STRAIT WESTERLIES. STORM WARNINGS FOR COAST AND
STRAIT...WITH PEAK WINDS WITH THE FROPA LATER TONIGHT AND THEN AGAIN
WITH THE SFC LOW AND BENT BACK OCCLUDED TROF BY MIDDAY SAY...PERHAPS
HOLDING OFF TIL MID AFTERNOON IN THE STRAIT. NO NEED TO GET
FANCY...THE MODELS SHOW A 977MB LOW CROSSING SOUTHERN VANCOUVER
ISLAND AND FILLING WITH VERY RAPID PRESSURE RISES BEHIND DURING THE
DAY ON SATURDAY. THE MM5GFS AND MESOETA BOTH SHOW THE PDX-BLI
GRADIENT GETTING UP TO AROUND SLY +20MB...SO THE GALE WARNING FOR
PUGET SOUND MAY HAVE TO BE UPGRADED TO A STORM WARNING. MM

&&

.WATCHES/WARNINGS/ADVISORIES...
1. HIGH WIND WARNING COAST...OLYMPICS...AND N INTERIOR TONIGHT AND
SAT
2. HIGH WIND WATCH REMAINDER OF THE AREA FOR SAT
3. FLOOD WATCHES...WARNINGS...OR ADVISORIES IN EFFECT FOR MASON...
THURSTON...AND GRAYS HARBOR COUNTIES
4. COASTAL FLOOD WATCH COAST SAT AND SAT NIGHT
5. STORM WARNING COASTAL WATERS AND STRAIT OF JUAN DE FUCA.
6. GALE NORTHERN INLAND WATERS...ADMIRALTY INLET...PUGET SOUND A
HOOD CANAL.

WEATHER.GOV/SEATTLE

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SEATTLE WA
726 PM PST FRI FEB 03 2006

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0724 PM     HIGH SUST WINDS  1 N OCEAN SHORES        46.98N 124.16W
02/03/2006  40 MPH           GRAYS HARBOR       WA   TRAINED SPOTTER

            WIND SE 40G60 AT 720 PM.

&&

DF