Lightning Strike in Washington, February 4, 2005

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
245 PM PST FRI FEB 4 2005

.SYNOPSIS...COOL ONSHORE FLOW WILL GIVE SHOWERS AND MOUNTAIN SNOW TO
THE AREA THROUGH TONIGHT. SHOWERS WILL GRADUALLY DECREASE
SATURDAY MORNING. A DEEPENING LOW WILL MOVE SOUTHEAST THROUGH THE
OFFSHORE WATERS SUNDAY BRINGING RAIN...MAINLY TO THE COAST. DRY AND
MILD CONDITIONS WILL RETURN TO THE AREA EARLY NEXT WEEK AS A RIDGE
OF HIGH PRESSURE ALOFT MOVES ACROSS THE REGION.

&&

.DISCUSSION...A SPLIT FLOW PATTERN IS IN PLACE WITH WESTERN
WASHINGTON UNDER THE INFLUENCE OF THE NORTHERN STREAM. POSTFRONTAL
ONSHORE FLOW IS GIVING MOUNTAIN SHOWERS WITH A CONVERGENCE ZONE THIS
AFTERNOON. THIS WILL CONTINUE THROUGH EARLY SAT BEFORE GRADUALLY
WEAKENING. A DEEPENING SURFACE LOW ASSOCIATED WITH AN UPPER LEVEL
SYSTEM DROPPING SOUTHEAST FROM THE GULF OF ALASKA WILL MOVE SE
THROUGH THE OFFSHORE WATERS ON SUN. MODEL TRENDS HAVE BEEN SLIGHTLY
FARTHER OFFSHORE WITH THIS SYSTEM. THEN A DRY...TRANQUIL PERIOD WILL
OCCUR EARLY TO MIDDLE OF NEXT WEEK AS SHORT WAVE RIDGING IN THE
NORTHERN STREAM PUSHES ACROSS THE REGION. EXTENDED MODELS CONTINUE
TO SHOW SPLIT FRONTS AFFECTING THE AREA FRI THRU NEXT WEEKEND.

.IN THE SHORT TERM...RADAR IMAGERY SHOWS THE PUGET SOUND CONVERGENCE
ZONE EXTENDING FROM JUST N OF STEVENS PASS WWD ACROSS SOUTHERN
SNOHOMISH COUNTY AND INTO THE NRN OLYMPICS. THE ZONE MAY SHIFT A BIT
SOUTH TODAY...BUT OVERALL EXPECT LITTLE CHANGE. ALSO SEE SHOWERS THE
LENGTH OF THE CASCADES WITH WLY FLOW. THE SNOW LEVEL HAS COME BELOW
4000 FEET AND WILL CONTINUE TO FALL TO 3000 FEET LATE THIS AFTN. IT
FALLS FURTHER TO 1500 FEET BY SAT MORNING. QPF OFF THE MESO MODELS
IS CONSISTENT WITH WLY FLOW...ABOUT 25 KT AT 850 MB...AND A
CONVERGENCE ZONE IN A MARGINALLY UNSTABLE ATMOSPHERE. IT SUPPORTS
MAINTENANCE OF A MARGINAL SNOW ADVISORY FOR THE CASCADES OVERNIGHT.
ONSHORE FLOW...CONVERGENCE...AND SHOWERS WILL DECREASE RAPIDLY BY
SAT AFTN.

.SUNDAY...MODELS CONTINUE TO SHOW THE DEVELOPMENT OF A WARM AND WET
SYSTEM NOW NEAR 50N/155W AS IT MOVES E INTO A COLD UPPER LOW THAT IS
DIGGING SE FROM THE GULF OF AK INTO THE PAC NW. THE ETA CONTINUES TO
DROP THE LOW THROUGH THE OFFSHORE WATERS INTO NW OREGON WHILE THE
GFS CARRIES THE LOW A LITTLE FARTHER TO THE EAST. THE ETA WITH ITS
MORE OFFSHORE SOLUTION AND DOWNSLOPE EFFECTS OF ELY FLOW OFF THE
CASCADES GIVES LESS PRECIPITATION TO THE INTERIOR THAN THE GFS THAT
CARRIES THE LOW A LITTLE FARTHER E. MODEL TRENDS GENERALLY SUPPORT
THE DRIER ETA SOLUTION THAT IS BEING FOLLOWED. IF PRECIPITATION
RATES ARE SUFFICIENT...THERE COULD BE A LITTLE WET SNOW SUN MORNING
ALONG HOOD CANAL AND IN LOWER ELEVATIONS OF THE E SLOPES OF THE
OLYMPICS AS 850 MB TEMPERATURES ARE COLD AND LOW LEVEL THICKNESSES
SUPPORT ISOTHERMAL 0C. HOWEVER DONT EXPECT ANY SNOW E OF PUGET
SOUND AS PRECIPITATION RATES WILL BE LOW AND DRYING/WARMING OFF THE
CASCADES SHOULD DOMINATE. WILL NEED TO KEEP AN EYE ON THIS THOUGH AS
A SHIFT FARTHER E COULD BRING MORE PRECIPITATION AND A BETTER CHANCE
OF LOWLAND SN E OF THE SOUND.

.MONDAY THROUGH FRIDAY...SHORT WAVE RIDGING AND OFFSHORE FLOW WILL
GIVE WARMING TO THE AREA. BY WED AND THU WE SEE SPRING RETURN WITH
TEMPERATURES INTO MID 50S AND POSSIBLY WARMER. SPLITTING FRONTAL
SYSTEMS FINALLY MOVE IN FRI OF NEXT WEEK FOR A CHANCE OF A LITTLE RA.

ALBRECHT

&&

.AVIATION...WINDS WILL REMAIN SOUTHERLY OVER THE CENTRAL PUGET SOUND
WITH A PUGET SOUND CONVERGENCE ZONE NEAR KPAE. MAINLY BROKEN SKIES
OVER THE LOWLANDS WITH CEILINGS 2K-4K FT...LOWER NEAR KPAE. CLOUDS
BECOMING MORE SCATTERED AFTER 03Z. GUSTY SOUTH WIND AT KSEA UNTIL
04Z...REMAINING SOUTHERLY ALL NIGHT. BURKE

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
   .SMALL CRAFT ADVISORY COAST...WEST ENTRANCE STRAIT OF JUAN DE
     FUCA...ADMIRALTY INLET AND PUGET SOUND/HOOD CANAL.
   .GALE WARNING CENTRAL STRAIT OF JUAN DE FUCA AND EAST ENTRANCE.
   .SNOW ADVISORY WEST SLOPES OF THE NORTH/CENTRAL CASCADES AND
PASSES     THROUGH 6 AM SAT.

.KATX...VCP21/CSR32 OPERATIONAL.

&&

WEATHER.GOV/SEATTLE