Funnel Cloud in Washington, February 21, 2007

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
830 AM PST WED FEB 21 2007

.SYNOPSIS...COOL ONSHORE FLOW WILL PRODUCE SHOWERS THROUGH THURSDAY
NIGHT...MOST NUMEROUS IN THE MOUNTAINS AND ALONG THE COAST. WET SNOW
OR ICE PELLETS MAY MIX IN WITH HEAVIER SHOWERS...ESPECIALLY DURING
THE LATE NIGHT AND MORNING HOURS. AFTER A MAINLY DRY DAY ON
FRIDAY...ANOTHER FRONTAL SYSTEM WILL BRING RAIN AND LOCALLY WINDY
CONDITIONS TO THE AREA FRIDAY NIGHT AND SATURDAY. A COOL SHOWERY
PATTERN WILL FOLLOW FOR THE REMAINDER OF THE WEEKEND.

&&

.SHORT TERM...AS THE COLD TROUGH CONTINUES TO DIG SOUTH THROUGH THE
OFFSHORE WATERS...COLD AIR CU IS NOW MOVING N THROUGH THE COASTAL
WATERS MAINLY ONTO THE OLYMPIC PENINSULA AND INTO VANCOUVER ISLAND.
SHOWER ACTIVITY HAS DECREASED OVER THE INTERIOR OF WESTERN
WASHINGTON AND WITH LOW LEVEL PRESSURE GRADIENTS TURNING MORE
SOUTHEASTERLY...LOW LEVEL FORCING IS PRETTY MUCH GONE DESPITE THE
UNSTABLE AIR MASS. SNOW SHOWER ACTIVITY IN THE CASCADES HAS BECOME
RATHER ISOLATED. THE CURRENT FORECAST OF LIKELY SHOWERS ALONG THE
COAST WITH A CHANCE OF THUNDERSTORMS LOOKS GOOD...WHILE THE INTERIOR
WILL ONLY SEE A CHANCE OF SHOWERS TODAY. PRECIPITATION WILL BE
LIGHT...SO DONT EXPECT TO SEE A REPEAT OF YESTERDAYS CONDITIONS
WHERE SMALL HAIL...WET SNOW...AND TSTMS ADDED TO THE MIX FOR A
LITTLE EXCITEMENT AT TIMES.

AN INSTANT OCCLUSION APPEARS TO BE DEVELOPING OFF THE CENTRAL OREGON
OFFSHORE WATERS THIS MORNING...AND THIS WILL LIFT NNE THRU THE AREA
LATE TONIGHT AND EARLY THU. SNOW LEVELS WILL BE QUITE LOW AS THIS
FEATURE PASSES ...AROUND 1000 FT... THU MORNING AND HEAVIER SHOWERS
COULD DRAG THE FREEZING LEVEL LOCALLY TO THE SURFACE AT TIMES.

ONCE THAT WAVE PASSES...EXPECT TO SEE SHOWERS BECOME MORE SCATTERED
DURING THE DAY WITH POSSIBLY SOME CLEARING DURING THE AFTN HOURS.

IN A NEW TWIST...THE NAM AND TO SOME DEGREE LATEST GFS
SOLUTIONS...BRING A WEAK SHORT WAVE TROUGH THRU THE AREA THU NIGHT
OR SOME TIME FRI. THIS MAKES THE TIMING OF THE BRIEF 12 HOUR OR SO
DRY PERIOD FOR SOMETIME FRIDAY DIFFICULT...BEFORE THE STRONGER
FRONTAL SYSTEM MOVES INTO THE AREA FRI NIGHT.

AT THIS TIME CURRENT FORECASTS LOOK GOOD. WILL TRY TO GET A BETTER
HANDLE ON THE FRI FORECAST WITH THE AFTERNOON PACKAGE. NO UPDATES
ARE PLANNED.  ALBRECHT

.LONG TERM...ANOTHER SIGNIFICANT FRONT PLOWS INTO THE REGION LATE
FRIDAY NIGHT AND SATURDAY FOR ANOTHER SOLID DUMP OF SNOWFALL IN THE
MOUNTAINS. A COOL AND SHOWERY PERIOD FOLLOWS FOR THE REMAINDER OF
THE WEEKEND WITH A COLD TROUGH OVERHEAD. CONFIDENCE IN DETAILS ON
MONDAY AND TUESDAY IS RATHER LOW. THE LATEST GFS BRINGS ZONAL FLOW
TO THE AREA WITH THE FOCUS OF PRECIPITATION SHIFTING SOUTH OF THE
FORECAST AREA. BEST TO LET FUTURE SHIFTS DECIDE ON THE DETAILS WHEN
THE MODELS SETTLE ON A SOLUTION. 27

&&

.AVIATION...EXPECT SCATTERED RAIN SHOWERS TO LINGER OVER THE COAST
AND INLAND AREAS THROUGH THE MORNING...DECREASING THIS AFTERNOON AS
THE UPPER LEVEL TROUGH DIGS OFFSHORE. PRECIPITATION WILL PICK UP
AGAIN LATE TONIGHT AND INTO TOMORROW MORNING AS UPPER TROUGH MOVES
ONSHORE AND INLAND. CEILINGS THIS MORNING ARE MOSTLY A SCT-BKN LAYER
AROUND 5000 FEET AND LOWER NEAR 2000 FEET IN AREAS OF SHOWER
ACTIVITY. SKIES THIS AFTERNOON WILL SCATTER OUT WITH LAYERS BETWEEN
5000 AND 10000 FEET.

AT KSEA...SCATTERED TO BROKEN MID LAYER AROUND 5000 FEET AND
POSSIBLY SHOWERS WITH LOWER CIGS NEAR 2500 FEET THROUGH THE
MORNING...IMPROVING IN THE AFTERNOON. WINDS SOUTHERLY 8 TO 14 KNOTS
THROUGH MIDDAY BECOMING LIGHT THIS AFTERNOON. COOK

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
  .SMALL CRAFT ADVISORY COASTAL WATERS.
  .SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS WEST ENTRANCE TO THE
     STRAIT.
  .SMALL CRAFT ADVISORY FOR ROUGH BAR CONDITIONS GRAYS HARBOR BAR.

WEATHER.GOV/SEATTLE