High Wind in Washington, March 28 to 29, 2010

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
900 PM PDT SUN MAR 28 2010

.SYNOPSIS...A STRONG LATE-SEASON FRONTAL SYSTEM WILL REACH THE COAST
TONIGHT THEN MOVE INLAND EARLY MONDAY MORNING...BRINGING RAIN...WIND
...AND MOUNTAIN SNOW. A BROAD UPPER LEVEL TROUGH WILL SETTLE OVER
THE PACIFIC NORTHWEST FOR COOL SHOWERY WEATHER THROUGH MIDWEEK.
ANOTHER FRONT WILL ARRIVE THURSDAY NIGHT OR FRIDAY...WITH ANOTHER
COOL SHOWERY PERIOD OVER THE WEEKEND.

&&

.SHORT TERM...A VIGOROUS LATE-SEASON FRONTAL SYSTEM IS MOVING INTO
WESTERN WASHINGTON THIS EVENING AS WE HAVE BEEN ADVERTISING FOR A
FEW DAYS NOW. A VARIETY OF WARNINGS AND ADVISORIES FOR THIS EVENT
ARE ALREADY IN EFFECT. THE FORECAST WITH REGARD TO THIS SYSTEM LOOKS
ON TRACK AND THE FLOOD WARNING...HIGH WIND WARNING...AND WINTER
STORM WARNING WILL BE UPDATED THIS EVENING WILL LITTLE CHANGE.

PRECIPITATION IS WIDESPREAD ACROSS THE FORECAST AREA. THERE ARE
INDICATIONS THAT PRECIPITATION INTENSITY IS STARTING TO INCREASE
ALONG THE NORTH COAST AND OVER THE SOUTH SLOPES OF THE OLYMPIC
MOUNTAINS THIS EVENING AS MODELS HAVE BEEN SHOWING. WINDS HAVE BEEN
INCREASING AS WELL...WITH SOLID GALES NOW OVER MUCH OF THE COASTAL
WATERS AND THE INLAND WATERS NORTH OF PUGET SOUND. WHIDBEY ISLAND --
USUALLY ONE OF THE STRONGEST WIND SPOTS IN THE NORTH INTERIOR --
REPORTED GUSTS TO 51 MPH LAST HOUR.

THE CORE OF THIS FEATURE WILL MOVE ACROSS WESTERN WASHINGTON DURING
THE NEXT 12 HOURS...AND THAT IS WHEN MOST OF THE ACTION WILL TAKE
PLACE. FOR MOST OF THE AREA THE WINDS WILL PEAK BETWEEN 10 PM AND 3
AM. BOTH THE HIGH WIND WARNING FOR THE COAST...MEANING SUSTAINED
WINDS 40 MPH OR GUSTS 60 MPH...AND THE WIND ADVISORY FOR THE NORTH
INTERIOR...MEANING WINDS JUST SLIGHTLY LESS...STILL LOOK LIKE GOOD
FORECASTS.

THE HEAVIEST PRECIPITATION OVER THE OLYMPICS IS ALSO FORECAST TO
OCCUR TONIGHT...AND MODELS CONTINUE TO SHOW STORM TOTALS OF JUST
OVER 4 INCHES ALONG THE SOUTH SLOPES OF THE OLYMPICS. THE HYDROLOGIC
MODEL STILL INDICATES A MINOR FLOOD FOR THE SKOKOMISH RIVER...WITH
THE SKOKOMISH RIVER NEAR POTLATCH CRESTING ESSENTIALLY AT FLOOD
STAGE MIDDAY MONDAY. I DO NOT SEE A REASON TO CHANGE THAT FORECAST
AT THIS TIME.

THE SNOWFALL EVENT FOR THE MOUNTAINS WILL UNFOLD MORE SLOWLY...BUT
AMONG THE WARNINGS WE HAVE OUT THAT IS PROBABLY THE ONE THAT MERITS
THE HIGHEST CONFIDENCE. THE FREEZING LEVEL AT QUILLAYUTE LATE THIS
AFTERNOON WAS ONLY 3800 FT...AND TEMPERATURES REMAINED CLOSE TO OR
BELOW FREEZING ALL DAY AT MOUNT BAKER AND PARADISE. THE SNOW LEVEL
WILL FALL TO AROUND 2000 FT MONDAY NIGHT BEHIND THE COLD FRONT AS
WESTERLY FLOW SUSTAINS PRECIPITATION. MESOSCALE MODELS SUGGEST
SNOWFALL AT HURRICANE RIDGE...MOUNT BAKER...AND PARADISE COULD BE IN
THE 2 TO 3 FT RANGE...WITH SOMEWHAT LESS AT SNOQUALMIE AND STEVENS
PASS. THERE IS A GOOD CHANCE OF RECEIVING HEAVY SNOW AMOUNTS -- BY
DEFINITION 12 INCHES IN 12 HOURS OR 18 INCHES IN 24 HOURS -- BY
MONDAY EVENING.

THE JET WILL SINK SOUTH TO CALIFORNIA AND ITS OFFSHORE WATERS ON
TUESDAY...LEAVING WESTERN WASHINGTON UNDER A COOL...SOMEWHAT
MOIST...AND WEAKLY UNSTABLE AIR MASS THROUGH WEDNESDAY. AT THIS TIME
IT DOES NOT LOOK LIKE ANY SIGNIFICANT ORGANIZED WEATHER SYSTEMS WILL
MOVE THROUGH THE FORECAST AREA DURING THIS PERIOD. SO POST-FRONTAL
SHOWERS WILL LIKELY DECREASE GRADUALLY TUESDAY THROUGH WEDNESDAY.
THE SNOW LEVEL WILL REMAIN LOW -- AROUND 2000 FT ON TUESDAY AND 1500
FT ON WEDNESDAY.

MCDONNAL

.LONG TERM...HERE IS THE LONG TERM SECTION FROM THE AFTERNOON
ISSUANCE OF THE FORECAST DISCUSSION -- AFTER ONE MORE COOL DAY
THURSDAY...MODELS ARE IN ROUGH AGREEMENT THAT THE NEXT SYSTEM
ARRIVES THURSDAY NIGHT OR FRIDAY. THIS FRONT ARRIVES FROM THE
NORTHWEST AND IS NOT LIKELY TO BE AS WET AS THE SYSTEM TONIGHT.
SHOWERS FOLLOW SATURDAY. INCREASED POPS INTO THE LIKELY CATEGORY FOR
BOTH DAYS. ANOTHER SYSTEM SEEMS TO FOLLOW SUNDAY SO HAVE LIKELY POPS
THEN AS WELL. DAYS WILL BE WARMER BUT NOT THAT WARM...HIGHS IN THE
LOW TO MID 50S. BURKE

&&

.HYDROLOGY...LITTLE CHANGE IN THE FORECAST. HEAVY RAIN IS FORECAST
OVER THE OLYMPICS TONIGHT WITH THE SNOW LEVEL 4000 FEET OR HIGHER.
AMOUNTS SHOULD BE HIGH ENOUGH TO DRIVE THE SKOKOMISH RIVER TO FLOOD
STAGE AND A FLOOD WARNING IS OUT. THE HEAVIEST RAIN WILL FALL FROM
03Z TO 15Z. AFTER THAT THE SNOW LEVEL WILL DROP...FINISHING AROUND
2000 FEET MONDAY NIGHT.

NO OTHER RIVER...INCLUDING THE GREEN...IS AT RISK OF FLOODING. BURKE

&&

.AVIATION...PERIODS OF RAIN TNGT THEN SHOWERS MON AND MON NITE. AIR
MASS IS MOIST...STABILIZING SOMEWHAT WITH WARM ADVECTION
TONIGHT...BUT DESTABILIZING DURING THE DAY ON MON BHND THE FNT.
STRONG SW FLOW ALF...PEAKING IN THE EARLY MORNING HOURS BUT STILL
FAIRLY STRONG THRU MON NITE. STRONG SFC ONSHORE FLOW BHND THE FNT.
AT 850MB THE TEMP DROPS FROM ARND +2C TNGT TO -2C MON AND 500MB
COOLS TO -33C MON NITE AND TUE AS THE COOL UPPER TROF WORKS IN OVER
THE WEST COAST...SO THERE WILL BE A CHANCE FOR MNLY AFTERNOON
THUNDERSTORMS...IF NOT MON AFTERNOON THEN TUE AFTERNOON. 19

KSEA...RAINY MVFR CIGS AND BLUSTERY SLY WINDS OVERNIGHT...BECMG
MORE SW BUT REMAINING BLUSTERY THRU THE DAY MON.

&&

.MARINE...WIDESPREAD GALES OVERNIGHT...THE 00Z WRFGFS SHOWS THE
STRONGEST WINDS OVER THE COASTAL WATERS AT MIDNIGHT WITH AREAS OF
45KT SSW WINDS JUST AHEAD OF FROPA. THE GALE WARNINGS INLAND WATERS
LOOK GOOD. IT WILL BE RATHER BLUSTERY BEHIND THE FRONT MON SO I MAY
HAVE TO LEAVE THE GALE WARNINGS UP THRU MON MORNING...AND WINDS WILL
CONTINUE TO RISE TO 20-30KT AS SHOWERS GO BY IN THE AFTERNOON.
AS THE AIR MASS DESTABILIZES MON AFTERNOON THERE WILL BE A GOOD
CHANCE OF SHOWERS...SQUALLS...AND A FEW THUNDERSTORMS. NOT UNUSUAL
IN EARLY SPRINT TO SEE BLUSTERY WEATHER PUNCTUATED WITH BRIEF GALE
FORCE GUSTS AS SHOWERS ROLL THRU...IN FACT AFTER LOOKING AT THE
WRFGFS IT WILL PROBABLY BE A GOOD IDEA TO KEEP GALE WARNINGS UP FOR
THE COASTAL WATERS RIGHT THRU THE DAY. 19

&&

.AVALANCHE...THE WELL ADVERTISED STRONG FRONT SHOULD CROSS THE
OLYMPICS AND CASCADES ON MONDAY MORNING. VERY STRONG RIDGE TOP
WINDS AND HEAVY SNOW NEAR AND WEST OF THE CREST SHOULD SPREAD FROM
THE OLYMPICS AND NORTH CASCADES SUNDAY NIGHT TO THE SOUTH CASCADES
ON MONDAY MORNING. A 170 KNOT JET IS INDICATED BY THE 12 UTC GFS
MODEL OVER THE MT HOOD AREA MONDAY AFTERNOON. THIS WEATHER SHOULD
CAUSE INCREASING POTENTIAL DEEP STORM OR WIND SLAB LAYERS TO DEVELOP
ON LEE SLOPES AT HIGHER ELEVATIONS IN THE OLYMPICS AND CASCADES ON
MONDAY. AN AVALANCHE WARNING IS IN EFFECT FOR MONDAY FOR AREAS OF
THE OLYMPICS AND CASCADES. PLEASE VISIT WWW.NWAC.US FOR DETAILS.
FERBER

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...FLOOD WARNING FOR SKOKOMISH RIVER.
     WINTER STORM WARNING OLYMPICS AND CASCADES.
     HIGH WIND WARNING FOR THE CENTRAL AND NORTH COAST.
     WIND ADVISORY NORTH INTERIOR.
     HIGH SURF ADVISORY CENTRAL AND NORTH COAST.
PZ...STORM WARNING COASTAL WATERS AND WEST ENTRANCE JUAN DE FUCA.
     GALE WARNING EAST ENTRANCE JUAN DE FUCA...NORTHERN INLAND
     WATERS...ADMIRALTY INLET AND PUGET SOUND/HOOD CANAL.
     SMALL CRAFT ADVISORY CENTRAL STRAIT JUAN DE FUCA.
     SMALL CRAFT ADVISORY GRAYS HARBOR BAR.

WWW.WEATHER.GOV/SEATTLE

FOR AN ILLUSTRATED VERSION OF THE FORECAST DISCUSSION PLEASE SEE
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML (ALL LOWERCASE).

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SEATTLE WA
559 PM PDT SUN MAR 28 2010

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

0430 PM     NON-TSTM WND GST 1 S AUBURN              47.28N 122.22W
03/28/2010  E45 MPH          KING               WA   TRAINED SPOTTER

            STRONG LINE OF SHOWERS PRODUCED GUSTY WINDS IN AUBURN.
            OBSERVER ESTIMATES FROM TREE BRANCHES DOWNED...ABOUT 45
            MPH. POWER WAS LOST IN PARTS OF AUBURN.

&&

DDAMICO