Gale Warning 390, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
230 PM ADT THU APR 17 2008

.MODEL DISCUSSION...MODEL MSLP INITIALIZATIONS LOOK OK. FORECAST
TRENDS THROUGH 60 HOURS ARE REASONABLE AND IN FAIR AGREEMENT.
SIGNIFICANT DIFFERENCES ARISE BEYOND 60 HOURS...ESPECIALLY IN THE
WESTERN DOMAIN. 12Z GFS ENSEMBLES FIT BETTER WITH 00Z GFS AND 12Z
ECMWF. SO WILL GO WITH 12Z MODEL SOLUTIONS THROUGH 60 HOURS THEN
GENERALLY HOLD WITH 00Z GFS MODELS.

.UPPER LEVELS...A BLOCKING PATTERN WITH A STRONG RIDGE WILL SET UP
OVER THE GULF AND MAINLAND ALASKA BY THIS WEEKEND AND HOLD THROUGH
THE MIDDLE OT NEXT WEEK. MEAN TROUGH POSITION GENERALLY REMAIN WEST
OF 150W. IN THE SHORT TERM...THE RIDGE ALONG 160W SHIFTS EAST AND
BUILDS ALONG 150W FRI AFTERNOON. AT THE SAME TIME THE LONG WAVE DIGS
SOUTH OVER THE BERING SEA AND SW FLOW SPREADS OVER MUCH OF WESTERN
ALASKA. BY SAT AFTERNOON THE RIDGE IS ESTABLISHED OVER THE NE
PACIFIC/GULF ALASKA/CENTRAL MAINLAND WITH THE MEAN TROUGH AXIS
GENERALLY WEST OF 160W.

.SURFACE...
EAST...PRESSURE GRADIENTS AND GAP WINDS WILL CONTINUE TO DIMINISH
ACROSS SOUTHCENTRAL AND NORTH GULF THROUGH THIS AFTERNOON. HIGH
PRESSURE BUILDS OVER THE GULF TONIGHT AND HOLDS THROUGH THE MIDDLE OF
NEXT WEEK. MAIN CONCERN WITH HIGH PRESSURE IS POTENTIAL DEVELOPMENT
OF MARINE STRATUS OVER THE GULF AND SPREADING INTO COASTAL
SOUTHCENTRAL/COOK INLET DURING THE WEEKEND. OTHERWISE...850 MB TEMPS
WARM CONSIDERABLY TO AROUND 0C SAT AND OTHER THEN A SLIGHT COOLING
SUN...WILL REMAIN WARM THROUGH EARLY NEXT WEEK. THIS LIKELY TO
TRANSLATE TO SPRING LIKE TEMPERATURES AND AFTERNOON SEABREEZES. IN
THE NEAR TERM...MOISTURE MOVING THROUGH THE RIDGE WILL BRING MAINLY
HIGH AND MID CLOUDS TO SOUTHCENTRAL TONIGHT...POSSIBLY LIGHT SNOW
ALONG THE ALASKA RANGE. CLEARING LIKELY ON FRI.

WEST...WEAK MOISTURE ADVECTION WITH SW/WLY FLOW WILL HOLD THE THREAT
OF SNOW OR MIX INTO FRI FOR THE SW MAINLAND. CUT-OFF LOW WELL SOUTH
OF THE EASTERN ALEUTIANS MOVES SOUTH OF DUTCH HARBOR SAT AFTERNOON.
THIS CENTER LIKELY TO CONTINUE NORTH AND WEAKEN OVER THE BERING SEA
SAT NIGHT/SUN. EXPECT LOW CENTER WILL BRING STRONG SOUTHERLY WINDS
AND WARMING TO THE AK PEN...BRISTOL BAY...AND EASTERN BERING SEA FRI
NIGHT/SAT. GUSTY WINDS WITH FRONTAL MOISTURE LIKELY TO SPREAD TO MUCH
OF COASTAL SW ALASKA BY SUN.
STRONG SWLY FLOW WILL WEAKEN OVER THE ALEUTIANS AND BERING SEA FRI AS
980S LOW CENTER OVER THE WESTERN BERING SEA MOVES INTO EASTERN RUSSIA
AND WEAKENS. NEXT STRONG LOW CENTER MOVES TO THE WESTERN ALEUTIANS
SAT NIGHT AND TO THE CENTRAL ALEUTIANS SUN AFTERNOON. EXPECT GALES
WITH THIS SYSTEM WITH POSSIBLE MIN STORMS ON THE BACKSIDE.

EXPECT UNSETTLED WEATHER OVER MUCH OF THE BERING SEA THROUGH MID NEXT
WEAK WITH AS A SERIES OF LOW CENTERS TRANSIT THE REGION.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALES 155,172,175, AND 185.
FIRE WEATHER...NONE.

RMC APR 08