Small Craft Advisory 169, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
200 PM AST MON FEB 25 2008

.MODEL DISCUSSION...MODEL INITIALIZATIONS ARE IN FAIR AGREEMENT.
FORECAST TREND WITH LOW COMPLEX OVER THE GULF OF ALASKA TUE NIGHT/WED
MORNING ARE IN GENERAL AGREEMENT IN PRESSURE...BUT HAVE SOME
POSITIONAL DIFFERENCES. THE AREA OF MAJOR CONSISTENCY ISSUES
CONTINUES TO BE WITH THE LOW COMPLEX MOVING SOUTH OF THE ALEUTIANS/
ALASKA PENINSULA WITHIN THE FIRST 60 HOURS. THE ECMWF MODEL SEEMS TO
HAVE BEEN THE MOST CONSISTENT OVER THE LAST COUPLE OF RUNS BY
DISPERSING THE ENERGY AMONGST A COUPLE OF LOW CENTERS. THE 12Z RUN OF
THE GFS ON THE OTHER HAND HAS GONE WITH A MORE CONSOLIDATED LOW
CENTER SOUTH OF THE AK PEN WED AFTERNOON. THIS WAS A SIGNIFICANT
SHIFT FROM THE 00Z RUN AND NOT REASONABLE IN LINE WITH UPPER LEVEL
DYNAMICS. BOTTOM LINE...WILL GO WITH THE 00Z RUN OF THE GFS MODEL
WHICH FLOWS BETTER WITH THE ECMWF AND SHOULD MINIMIZE FORECAST
CHANGES IN THE CURRENT GRID SET.

.UPPER LEVELS...
IR SAT IMAGE SHOWS UPPER LOW MOVING SOUTH ACROSS NORTHERN BRISTOL BAY
THIS AFTERNOON. THIS FEATURE IS FORECAST TO CONTINUE MOVING SOUTHWEST
AND NEAR THE WESTERN AK PEN/EASTERN ALEUTIANS WILL INTERACT WITH A
SECONDARY CENTER UNDERCUTTING THE ALEUTIANS TUE. THE RESULT OF THIS
INTERACTION WILL BE A LOW CENTER WHICH MOVES SOUTH OF THE AK PEN WED
NIGHT WITH A TROUGH EXTENDING TO A WEAKER CENTER OVER THE CENTRAL
BERING SEA. THE MOST CONSISTENT FEATURE APPEARS TO BE THE HIGH CENTER
OVER THE BERING SEA WHICH IS SQUEEZED NORTH TO OVER THE RUSSIAN
ARCTIC TUE. THIS FEATURE HAS REMAINED RELATIVELY UNCHANGED OVER THE
LAST SEVERAL RUNS AND IS FORECAST TO MAINTAIN ITS POSITION THROUGH
THURSDAY. THIS MEANS THAT AFTER A LOW CENTER MOVES INLAND OVER THE
EASTERN GULF WED THAT THE RIDGE WILL REBUILD OVER THE EAST GULF AND
EXTEND NW TOWARD TO THE HIGH OVER THE RUSSIAN ARCTIC.

.SHORT TERM FORECAST...
.EAST...LOW CENTER OVER THE NORTHERN GULF WILL CONTINUE SE MOVEMENT
AND SHOULD DISSIPATE TUE. SNOW SHOWERS OVER THE NORTH GULF AND
COASTAL LOCATIONS WILL MOVE SW TOWARD THE WESTERN GULF TONIGHT. GALES
LIKELY INTO THE SOUTHERN GULF TONIGHT AHEAD OF NORTH MOVING LOW
COMPLEX. GALES LIKELY TO SPREAD TO NORTHERN GULF AREAS TUE/TUE NIGHT
ALONG WITH A RESURGENCE OF MOISTURE TO COASTAL LOCATIONS. GENERAL LOW
CENTERS PART WAYS TUE NIGHT WITH THE PARENT CENTER MOVING TOWARD SE
ALASKA AND THE TRIPLE POINT SLIDING SOUTH OF KODIAK WED MORNING. IF
THIS PATTERN HOLDS...EXPECT WINDS TO DIMINISH OVER THE GULF...
HOWEVER RAIN AND SNOW LIKELY TO CONTINUE OVER THE WESTERN GULF WITH A
THREAT OF SNOW TO SOUTHCENTRAL AND NORTH GULF COAST WED.

.WEST...LIGHT SNOW/SNOW SHOWERS OVER THE KUSKOKWIM VALLEY AND BRISTOL
BAY THIS AFTERNOON SHOULD END TONIGHT AS UPPER LEVEL CENTER TRACKS
SOUTH OF THE AREA. EXPECT SNOW WITH THIS CENTER TO SPREAD TO THE AK
PEN AND EASTERN ALEUTIANS TONIGHT. EXPECT DRYING OVER THE SW MAINLAND
AFTER PASSAGE OF UPPER LEVEL CENTER TONIGHT. ONSET OF SE FLOW WITH
LOW CENTERS MOVING SOUTH OF KODIAK MAY BRING SOME OVERRUNNING SNOW TO
BRISTOL BAY WED AND THE KUSKOKWIM VALLEY AND KUSKOKWIM DELTA WED
NIGHT AND THU. TRIPLE POINT DEVELOPS ALONG THE FRONTAL SYSTEM NEAR
THE WESTERN ALEUTIANS THIS AFTERNOON AND INTENSIFIES AS IT TRACKS
SOUTH OF THE EASTERN ALEUTIANS TUE NIGHT. STRONG WINDS OVER THE
WESTERN/CENTRAL ALEUTIANS WILL SLOWLY DIMINISH THROUGH TUE. WINDS
OVER THE EASTERN ALEUTIANS LIKELY TO CONTINUE AND SPREAD EAST TUE AND
WED.

.LONG TERM FORECAST...MADE LITTLE CHANGE TO EXTENDED GRIDS DUE TO
GENERALLY POOR MODEL CONSISTENCY.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE... GALES 120 130 132 138 155 170 172 175 176 185.
FIRE WEATHER...NONE.

RMC FEB 08