High Wind in Washington, February 7, 2012

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
255 AM PST TUE FEB 7 2012

.SYNOPSIS...STRONG HIGH PRES EAST OF THE CASCADES WILL GIVE DRY AND
MILD CONDITIONS TODAY. LOCALLY WINDY CONDITIONS WILL OCCUR NEAR THE
WEST SLOPES OF THE CASCADES THIS MORNING. A WEAK FRONT WILL APPROACH
THE AREA FROM THE SOUTHWEST TONIGHT. THEN A WEAKENING FRONTAL SYSTEM
WILL DISSIPATE AS THE MOVE ONSHORE WEDNESDAY. ANOTHER DISTURBANCE
WILL MOVE NORTH ALONG THE COAST WEDNESDAY NIGHT INTO EARLY THURSDAY.
ANOTHER MILD DAY IS EXPECTED THURSDAY AS OFFSHORE FLOW INCREASES.
THE UPPER RIDGE WILL BREAK DOWN THIS WEEKEND GIVING A CHANGE TO A
MORE TYPICAL AND WETTER REGIME.

&&

.SHORT TERM...A STRONG 1045 MB SURFACE HIGH OVER THE SOUTHERN
CANADIAN PRAIRIES AND A RIDGE EXTENDING WESTWARD INTO SOUTHERN
BRITISH COLUMBIA IS GIVING OFFSHORE PRES GRADIENTS THIS MORNING.
MEANWHILE...A NEGATIVE TILT FRONTAL SYSTEM EXTENDING SE FROM A 965
MB LOW CENTERED NEAR 47N 149W INTO NORTHERN CALIFORNIA APPEARS TO BE
STRETCHING OUT AND DISSIPATING AS IT LIFTS NE INTO THE RIDGE. THE
DRIER 06Z GFS AND NAM12 SOLUTIONS ARE GENERALLY PREFERRED TO THE
WETTER ECMWF AS THIS FRONT ENCOUNTERS THE VERY DRY AND STABLE AIR
OVER W WASHINGTON AND THE STRONG UPPER RIDGE IN PLACE. AFTER
WEAKENING SOMEWHAT ON WEDNESDAY AS THE DISSIPATING FRONT LIFTS
NORTHEAST TOWARD THE AREA...THE RIDGE REBUILDS AND OFFSHORE FLOW
STRENGTHENS ON THURSDAY AND THURSDAY NIGHT OVER THE AREA AS YET
ANOTHER NEGATIVE TILT FRONT LIFTS NE TOWARD THE AREA.

SATELLITE IMAGERY SHOWS THE FRONT TO THE SOUTHWEST REALLY LOSING ITS
PUNCH AS SOUTHERN STREAM ENERGY DRIVES INTO SOUTHERN CALIFORNIA AND
THE RIDGE TO THE NE OF THE AREA PERSISTS. SO CLOUDS WERE DECREASED
ACROSS THE AREA TODAY AND TEMPERATURES WERE RAISED WELL INTO THE
50S. TEMPERATURES MAY BE A FEW DEGREES COOLER TODAY DESPITE THE
SUNSHINE AND WARM MORNING START SINCE OFFSHORE PRES GRADIENTS WILL
BE IN THE PROCESS OF RELAXING THIS MORNING. LOCALLY WINDY CONDITIONS
CONTINUE THIS MORNING NEAR THE CASCADE PASSES WITH STRONG CROSS
CASCADE PRES GRADIENTS. A SMALL AREA OF VERY WINDY CONDITIONS...
ABOUT 5 MPH BELOW HIGH WIND WARNING CRITERIA...HAS BEEN OCCURRING
AROUND ENUMCLAW WITH UPPER LEVEL WINDS AND THE HEIGHT OF THE
INVERSION MARGINALLY SUPPORTING MOUNTAIN WAVE CONDITIONS. THE THREAT
FOR FURTHER MOUNTAIN WAVE ACTIVITY IS DECREASING AS THE DEPTH OF THE
LOW LEVEL OFFSHORE FLOW DECREASES.

MAINLY MID AND HIGH CLOUDS WILL RAPIDLY INCREASE OVERNIGHT THROUGH
WEDNESDAY AS THE FRONT TO THE SOUTHWEST LIFTS NE OVER THE AREA. THE
FRONT IS LOSING ITS STRENGTH AND IS MOVING INTO A STABLE AND DRY AIR
MASS...SO EXPECT ANY PRECIPITATION THAT FALLS...MAINLY ALONG THE
COAST AND OVER THE OLYMPICS...TO BE QUITE LIGHT.

ANOTHER WEAK WAVE LIFTS NORTH ACROSS THE OFFSHORE AND COASTAL WATERS
WED NIGHT INTO THU MORNING. THIS FEATURE WILL ALSO GIVE CLOUDS AND A
CHANCE OF PRECIPITATION...BUT WITH INCREASING OFFSHORE LOW LEVEL
FLOW EXPECT THE PRECIPITATION CHANCES TO BE RATHER LOW AND CLOUDS TO
HAVE SOME BREAKS.

THURSDAY AFTERNOON IS STARTING TO LOOK LIKE IT COULD BE QUITE MILD
ONCE AGAIN AS OFFSHORE PRES GRADIENTS INCREASE AHEAD OF ANOTHER
NEGATIVELY TILTED FRONT. THE UW MM5 SOLUTION SHOWS TEMPERATURES
POSSIBLY HITTING 60 ONCE AGAIN ON THU. CONDITIONS NEAR THE CASCADE
FOOTHILLS COULD GET RATHER WINDY AGAIN ESPECIALLY THURSDAY NIGHT AS
CONDITIONS APPEAR SOMEWHAT SIMILAR TO LATE MON NIGHT INTO TUE
MORNING. FORECAST TEMPERATURES FOR THURSDAY WERE PUSHED INTO THE MID
50S THURSDAY FOR NOW AND MAY BE PUSHED FURTHER IF MODEL TRENDS
PERSIST. ALBRECHT

.LONG TERM...ANOTHER DISSIPATING NEGATIVE TILT FRONT MOVES NE ACROSS
THE AREA ON FRIDAY GIVING AN INCREASE IN CLOUDS...A CHANCE OF LIGHT
PRECIPITATION...AND COOLER YET MILD CONDITIONS. MODELS SHOW SOME
CHANGE IN THE PATTERN OVER THE WEEKEND AS THE UPPER RIDGE BREAKS
DOWN AND A SERIES OF SYSTEMS START TO MOVE ACROSS THE AREA. MODEL
CONSISTENCY AND CONTINUITY REALLY BREAKS DOWN LATER NEXT WEEKEND
THROUGH NEXT WEEK AS SOME RIDGING BUILDS 135W TO 140W AND SYSTEMS
DRIVE MAINLY SE INTO CALIFORNIA AND SOUTHERN OREGON. NO CHANGES WERE
MADE TO THE GOING FORECAST. ALBRECHT

&&

.HYDROLOGY...NO FLOODING IS EXPECTED IN THE FORECAST AREA DURING THE
NEXT 7 DAYS.

&&

.AVIATION...AN UPPER LEVEL RIDGE WILL REMAIN OVER THE AREA TODAY.
OFFSHORE FLOW WILL PEAK THIS MORNING THEN EASE THIS AFTERNOON. THE
AIR MASS ACROSS WESTERN WA IS DRY AND STABLE WITH VFR CONDITIONS.
HOWEVER...MAY SEE PATCHY FOG IN THE SOUTH SOUND AT KOLM THIS
MORNING. A WEAK FRONT WILL CLIP THE REGION TONIGHT WITH LIGHT RAIN
POSSIBLE. CIGS SHOULD REMAIN VFR AS ONSHORE FLOW CONTINUES. 33

KSEA...GUSTY EAST WINDS 11010G20KT WILL CONTINUE THROUGH MID MORNING
THEN EASE AND BECOME SE THIS AFTERNOON. VFR CONDITIONS WILL PREVAIL.
EXPECT INCREASING CLOUDS TONIGHT WITH A CHANCE OF LIGHT RAIN EARLY
WED. 33

&&

.MARINE...THE CURRENT FORECAST REMAINS ON TRACK. OFFSHORE FLOW WILL
PEAK EARLY THIS MORNING THEN GRADUALLY EASE THROUGH THE AFTERNOON.
GALE WARNINGS REMAIN IN EFFECT FOR THE WEST ENTRANCE OF JUAN DE FUCA
AND ADJACENT COASTAL WATERS ZONE PZ150. EAST WINDS WILL REMAIN IN
SMALL CRAFT ADVISORY RANGE FOR THE REMAINDER COASTAL WATER ZONES.

A PAIR OF WEAK FRONTS WILL CROSS THE COASTAL WATERS TUE AND WED. A
WARM FRONT WILL BRUSH THE WATERS WED NIGHT. 33

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...WIND ADVISORY EAST PUGET SOUND LOWLANDS UNTIL NOON TODAY.
PZ...GALE WARNING WEST ENTRANCE JUAN DE FUCA AND CAPE FLATTERY
      TO JAMES ISLAND AND OUT 10 NM.
     SMALL CRAFT ADVISORY REMAINING COASTAL WATERS AND CENTRAL
      AND EASTERN STRAIT JUAN DE FUCA.

WWW.WEATHER.GOV/SEATTLE

YOU CAN SEE AN ILLUSTRATED VERSION OF THE FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML.