Blizzard Watch 18, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
130 PM ADT WED MAR 12 2008

.MODEL DISCUSSION...MODELS INITIALIZED WELL THIS MORNING. FORECAST
TREND OFF THE GFS40/ECMWF THROUGH 72 HRS ARE REASONABLE AND IN GOOD
AGREEMENT. MODELS DIVERGE SOME BEYOND THIS POINT. GFS HAS BEEN FAIRLY
CONSISTENT OVER THE LAST COUPLE OF RUNS...SO WILL CONTINUE WITH GFS
BLEND OUT TO DAY 5.

.UPPER LEVELS...
THE EASTWARD PROGRESSION OF THE TROUGH OVER SOUTHCENTRAL ALASKA WILL
BE SLOWED SOME AS A SHORT WAVE MOVES ACROSS WESTERN ALASKA. GENERAL
TROUGH AXIS MOVES INTO WESTERN ALASKA AND SE ALASKA FRI AFTERNOON.
RIDGE OVER THE EASTERN BERING SEA AND AK PEN MOVES TO OVER KODIAK AND
SW ALASKA FRI AFTERNOON. RIDGE CONTINUES TO OVER SOUTHCENTRAL
ALASKA/GULF FRI NIGHT AND TO THE EASTERN MAINLAND AND EASTERN GULF
SAT AFTERNOON. LOW COMPLEX NEAR THE WESTERN ALEUTIANS CONSOLIDATES
INTO ONE MAIN CENTER OVER THE CENTRAL ALEUTIANS FRI NIGHT. A
SECONDARY CENTER LIKELY TO MOVE TO THE EASTERN BERING SEA/BRISTOL BAY
AS A SOUTHWESTERLY JET SETS UP OVER THE WESTERN GULF FRI NIGHT/SAT
MORNING.

.SURFACE...
EAST...SOUTHCENTRAL ALASKA SHOULD REMAIN GENERALLY MOSTLY CLOUDY WITH
THE THREAT OF FLURRIES OR SNOW SHOWERS UNTIL PASSAGE OF THE UPPER
TROUGH THU AFTERNOON. THE ONSET OF NW FLOW IN ADVANCE OF UPPER RIDGE
AND BUILDING N/S PRESSURE GRADIENT ALONG THE NORTH GULF THU NIGHT/
FRI SHOULD USHER IN DRIER WEATHER. BUILDING PRESSURE/TEMP GRADIENTS
ALONG THE NORTH GULF THU NIGHT LIKELY TO PRODUCE BRISK AND GUSTY GAP
WINDS. A FRONTAL TROUGH MOVING INTO THE WESTERN GULF FRI NIGHT WILL
BRING A SHOT AT RAIN/SNOW AND WIND. FRONTAL TROUGH MOVES TO THE
NORTHERN/CENTRAL GULF SAT AFTERNOON. EXPECT GENERALLY A MIX OF RAIN
AND SNOW ALONG COASTAL AREAS WITH STRONG GAP WINDS ACROSS PORTIONS OF
SOUTHCENTRAL ALASKA.

.WEST..SAT IMAGERY CONTINUES TO INDICATE STRATUS HOLDING OVER
SIGNIFICANT PORTIONS OF SW ALASKA. MORNING SOUNDINGS OVER THE DELTA
AND BRISTOL BAY SHOWED CLOUD TOPS 3500-4000 FT. MAY SEE SOME CLEARING
ALONG THE NORTH COAST OF BRISTOL BAY OVER THE NEXT 24 HRS WITH THE
ONSET OF OFFSHORE FLOW. THE DELTA WILL LIKELY HOLD WITH STRATUS UNTIL
THE ONSET OF WINDS IN ADVANCE OF FRONTAL TROUGH FRI. LOW CENTER
APPROACHING THE WESTERN ALEUTIANS MOVES WEST OF ADAK TONIGHT THEN
SHIFTS WEST AND DISSIPATES LATER THU. FRONTAL TROUGH ASSOCIATED WITH
THIS CENTER MOVES EAST AND NORTH AND WEAKENS. HOWEVER...WINDS WITH
COMBINATION OF SNOW COULD CAUSE BRIEF BLIZZARD CONDITIONS OVER THE
PRIBILOFS THU AFTERNOON AND EVENING. A STRONG SECONDARY CENTER MOVES
TO THE CENTRAL ALEUTIANS THU NIGHT AND TO NEAR ATKA FRI NIGHT WHERE
IT SLOWLY WEAKENS. ASSOCIATED FRONTAL TROUGH MOVES TO THE EASTERN
ALEUTIANS THU NIGHT AND TO ALONG THE SW COAST/BRISTOL BAY FRI NIGHT.

.LONG RANGE...WENT WITH GFS BLEND WITH CURRENT GRID SET.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...BLIZZARD WATCH ZONE 195 THU.
MARINE...STORM 176. GALES 170 171 172 175 179 AND 185.
FIRE WEATHER...NONE.

RMC MAR 08