Small Craft Advisory 1090, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 PM AST TUE DEC 25 2007

.MODEL DISCUSSION...
THE MODELS ARE IN FAIRLY GOOD AGREEMENT THROUGH WEDNESDAY AFTERNOON
THEN THE SOLUTIONS BEGIN TO DIVERSE WITH RESPECT TO THE LOW MOVING
INTO BRISTOL BAY WEDNESDAY NIGHT. THOUGH ALL THE MODELS MOVE THE LOW
IN TO THE GULF THURSDAY NIGHT, THE NAM MODEL KEEPS THE CENTER A
LITTLE FURTHER WEST OVER KODIAK ISLAND WHILE THE GFS, UKMET AND ECMWF
HAS IT OVER THE WESTERN OR CENTRAL GULF. THOUGH IT IS HARD TO SAY
WHICH HAS THE BETTER SOLUTION, I LIKE THE GFS BECAUSE IT HAS BETTER
CONSISTENCY THAN THE OTHER MODELS.

.ANALYSIS AND UPPER LEVELS...
CURRENT SATELLITE LOOP SHOWS THE LOW IN THE CENTRAL GULF MOVE EAST. A
WEAKER LOW HAS FORMER NEAR MIDDLETON ISLAND AND IS KEEPING AN AREA OF
SHOWERS ALONG THE CENTRAL GULF COAST. COLD AIR MOVING INTO THE COOK
INLET AND KENAI PENINSULA IS COLLIDING WITH THE WARMER FROM PRINCE
WILLIAM SOUND AND IS CREATING AN AREA OF SNOW ALONG THE RAILBELT.

A SMALL LOW OVER THE OVER THE NORTHERN BERING SEA WILL MOVE SOME SNOW
ONTO THE KUSKOKWIM DELTA COAST BY LATE AFTERNOON.

THE LARGE LOW SOUTH OF THE CENTRAL ALEUTIANS CONTINUES TO MOVE
NORTHEAST AND WILL MOVE STRONG WINDS INTO THE CENTRAL ALEUTIANS THIS
AFTERNOON.

A SHORT WAVE UPPER TROUGH OVER OVER KODIAK CONTINUES TO MOVE
NORTHEAST TOWARD COOK INLET. THE UPPER RIDGE OVER WESTERN CANADA IS
STILL HOLDING.

.SHORT TERM FORECAST...
THE UPPER TROUGH OVER KODIAK ISLAND WILL MOVE THROUGH THE COOK INLET
AND SUSITNA VALLEY TONIGHT THEN WEAK OVER THE CENTRAL INTERIOR
WEDNESDAY MORNING. A UPPER RIDGE DEVELOPING OVER BRISTOL BAY AND THE
ALASKA PENINSULA WILL MOVE NORTHEAST INTO THE GULF AND SOUTH CENTRAL
ALASKA WEDNESDAY AFTERNOON THEN CONTINUE NORTH AND EAST INTO WESTERN
CANADA AND NORTHERN ALASKA THURSDAY.

SOUTH CENTRAL ALASKA AND THE GULF...
THE PUSH OF COLD AIR INTO THE SUSITNA VALLEY AND KENAI PENINSULA WILL
CONTINUE TO PRODUCE AREAS OF SNOW THROUGHOUT THE AREA UNTIL THE UPPER
TROUGH MOVES THROUGH TONIGHT. CLEARER AND COLDER WEATHER WILL MOVE
DEVELOP WEDNESDAY WITH THE UPPER RIDGE. MORE CLOUD WILL MORE UP FROM
THE SOUTH AS A WEATHER FRONT MOVES INTO THE CENTRAL GULF THURSDAY.
SNOW, RAIN AND SOME STRONG WINDS WILL MOVE INTO KODIAK ISLAND LATE
WEDNESDAY AND WEDNESDAY NIGHT AND WILL SPREAD TO THE CENTRAL GULF
COAST EARLY THURSDAY.

SOUTHWEST ALASKA, BERING SEA AND ALEUTIANS...
A RIDGE OVER THE INTERIOR SOUTHWEST WILL MOVE INTO THE TANANA VALLEY
WEDNESDAY MORNING.

A WEAK LOW OVER THE NORTHERN BERING WILL SWING THE REMAINS OF ITS
COLD FRONT TO THE KUSKOKWIM DELTA COAST BEFORE BOTH DISSIPATES LATE
TONIGHT. THIS WILL PRODUCE SOME ALONG THE COAST TONIGHT.

A STRONG LOW SOUTH OF THE CENTRAL ALEUTIANS WILL MOVE NORTHEAST
THROUGH DUTCH HARBOR WEDNESDAY MORNING AND CONTINUE TO MOVE ALONG THE
NORTH SIDE OF THE ALASKA PENINSULA INTO BRISTOL BAY THU MORNING THEN
WILL MOVE TO NEAR KODIAK ISLAND THU AFTERNOON. STRONG WINDS
ASSOCIATED WITH THIS SYSTEM WILL MOVE INTO THE CENTRAL AND EASTERN
ALEUTIANS THIS EVENING WITH SPREAD INTO THE AK PEN AND BRISTOL BAY
WEDNESDAY.

THE BLIZZARD WATCH FOR THE AK PEN IS LOOKING DOUBTFUL AT THIS TIME
BECAUSE THE MODELS ARE INDICATING A LOT OF WARMER AIR WILL MOVE INTO
WITH THE STRONG SOUTHWEST WINDS AND THE SNOW BEGINNING THIS EVENING
WILL RAPIDLY CHANGE TO RAIN TONIGHT.

.LONG TERM FORECAST...
THE LOW NEAR KODIAK THURSDAY WILL MOVE INTO THE CENTRAL GULF THURSDAY
NIGHT THEN SLOWLY WEAKEN THERE THROUGH SATURDAY. MOST OF THE STRONGER
WINDS AND PRECIPITATION WILL REMAIN ALONG THE COAST. ANOTHER LOW WILL
DEVELOP OVER THE CENTRAL BERING SEA THU NIGHT THEN DRIFT TO NEAR
SAINT MATTHEW ISLAND SAT.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...BLIZZARD WATCH FOR THE ALASKA PENINSULA.
MARINE...GALE 120, 129, 130, 132, 150, 155, 160, 165, 170, 172, 175,
179.
FIRE WEATHER...NONE.

NM DEC 07