Small Craft Advisory 172, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
200 PM AST TUE FEB 26 2008

.MODEL DISCUSSION...FORECAST MODEL SOLUTIONS OUT WEST ARE FAIRLY
CONSISTENT ON THE LAST TWO RUNS. DIFFERENCES OCCUR MAINLY IN THE
EAST. BIGGEST CHANGE IS WITH FURTHER EAST POSITIONING OF SURFACE LOW
NEAR KODIAK ISLAND WED NIGHT AND THE MAINTENANCE OF THIS TREND
THROUGH THU. ALTHOUGH THE FRONTAL TROUGH ASSOCIATED WITH THIS FEATURE
IS SIMILAR ON BOTH THE 00Z-12Z MODEL RUNS. FURTHER EAST POSITION OF
LOW NEAR KODIAK WOULD CAUSE SIGNIFICANT CHANGE IN THE WIND FORECAST.
SO FOR NOW WILL GENERALLY LEAN WITH 00Z GFS RUN THIS FOR THIS
FORECAST PACKAGE.

.UPPER LEVELS...
NO MAJOR CHANGES IN THE UPPER AIR PATTERN. THE BERING SEA HIGH HAS
PINCHED OFF NORTH AND IS ON ITS WAY TO THE RUSSIAN ARCTIC. UPPER LOW
CENTER EVIDENT ON SAT IMAGE SHOWS WEST MOVEMENT TO JUST SOUTH OF THE
PRIBILOFS THIS AFTERNOON. EXPECT THIS CENTER TO WEAKEN NEAR THE
EASTERN ALEUTIANS AS DEVELOPING CENTER OVER THE NORTH PACIFIC MOVES
SOUTH OF THE AK PEN WED NIGHT/THU. THIS CENTER EVENTUALLY DROPS SOUTH
OF THE GULF OF ALASKA FRI AS THE LONG WAVE DIGS SW FROM THE CANADIAN
ARCTIC TO OVER THE SOUTHERN MAINLAND. THE RIDGE THEN REBUILDS BACK
OVER THE EASTERN BERING SEA FRIDAY AS THE LONG WAVE MOVES TO ALONG
THE ALEUTIANS.

.SHORT TERM FORECAST...
.EAST...MOISTURE MOVING NORTH INTO THE GULF WITH LOW COMPLEX IS
STARTING TO SHOW ON THE MIDDLETON ISLAND RADAR. EXPECT SNOW WILL
SPREAD TO MUCH OF THE GULF AND COASTAL LOCATIONS THROUGH TONIGHT.
FRONTAL TROUGH WILL BE FAIRLY WEAK AS IT MOVES OVER THE SOUTHERN
MAINLAND...SO WOULD NOT EXPECT MUCH PRECIPITATION AS IT MOVES INLAND.
WINDY CONDITIONS LIKELY WITH PRECIPITATION OVER THE GULF TONIGHT
AHEAD OF ADVANCE FRONTAL TROUGH. EXPECT GENERALLY GALES TONIGHT...BUT
WINDS SHOULD SETTLE DOWN SOME WED. POSITION OF NEXT LOW TO MOVE SW OF
KODIAK WED NIGHT IS STILL SOMEWHAT UNCERTAIN. HOWEVER...EXPECT
GENERAL FRONTAL TROUGH TO MOVE TO OVER KODIAK ISLAND WED NIGHT AND TO
THE NORTH GULF THU. EXPECT ANOTHER BATCH OF WINDS AHEAD OF THIS
SYSTEM ALONG WITH SOMEWHAT WARMER TEMPS AND POSSIBILITY OF MIXED
PRECIPITATION.

.WEST...LIGHT SNOW OVER BRISTOL BAY WILL WEAKEN TONIGHT AS THE WAVE
MOVES WEST. GENERALLY DRY CONDITIONS WILL HOLD OVER SW ALASKA THROUGH
WED...MAY SEE A LITTLE SNOW TO EASTERN BRISTOL BAY WED NIGHT/THU WITH
WEAK OVERRUNNING. WINDS WILL GRADUALLY DIMINISH OVER THE WESTERN AND
CENTRAL ALEUTIANS TONIGHT AS FRONT OVER THE WESTERN ALEUTIANS
ELONGATES AND TRIPLE POINT MOVES SOUTH OF UNALASKA. GUSTY EAST TO
NORTH WINDS WILL LIKELY SPREAD TO THE EAST ALEUTIANS AND AK PEN
TONIGHT AND WED. BRISK AND GUSTY NORTH WINDS LIKELY OVER THE AK PEN
AND EXTREME EASTERN ALEUTIANS WED NIGHT...AND AK PEN THU. STRONG SE
WINDS LIKELY OVER THE WESTERN ALEUTIANS WED NIGHT/THU IN ADVANCE OF
APPROACHING FRONTAL TROUGH.

.LONG TERM FORECAST...MODEL UNCERTAINTY...LITTLE CHANGE.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...MARINE...GALES 120 130 132 138 155 170 172 175 176.
FIRE WEATHER...NONE.

RMC FEB 08