High Wind in Alaska, February 4 to 5, 2005

AREA FORECAST DISCUSSION SOUTHWEST ALASKA
500 AM AST FRI FEB 4 2005

.DISCUSSION...

UPPER LEVEL RIDGE OVER THE EASTERN BERING AND WESTERN ALASKA THIS
MORNING WITH CUTOFF LOWS PERSISTING OVER THE NORTH GULF COAST AND
SOUTH OF KAMCHATKA. AT THE SURFACE A WEAK TROUGH CONTINUES OVER THE
NORTH GULF COAST WITH HIGH PRESSURE OVER THE INTERIOR. A WEATHER
FRONT LIES ACROSS THE BERING TO THE PRIBILOFS BEFORE BENDING
SOUTHEAST ACROSS THE COLD BAY AREA. WEAK LOWS ARE IN THE CENTRAL
BERING AND SOUTH OF COLD BAY...AND AROUND 1000 MILES SOUTH OF ATTU IN
THE NORTH PACIFIC.

MODELS ARE IN FAIRLY GOOD AGREEMENT FOR THE SHORT TERM SO WENT WITH
THE GFS ACROSS THE FORECAST AREA.

IN THE EAST...GUSTY WIND THROUGH THE COPPER RIVER DELTA WILL COME TO
AN END LATER TODAY AS THE NORTH GULF COAST TROUGH MOVES INTO
SOUTHEAST ALASKA. HIGH PRESSURE BUILDING INTO THE GULF LATER TODAY AT
BOTH THE SURFACE AND ALOFT WILL END THE GUSTY NORTHWEST FLOW OFF THE
AKPEN ACROSS KODIAK ISLAND. THESE WINDS HAVE BEEN A PERSISTENT SATPIX
FEATURE FOR SEVERAL DAYS. CLEAR SKIES AND COLD DRY AIR WILL BEGIN TO
GIVE WAY TO AN APPROACHING FRONT SAT WHEN SNOW SHOWERS AFFECT KODIAK
ISLAND WITH GALES AND STORMS OVER THE MARINE AREAS. LIGHT SNOW IS
STILL FORECAST TO MOVE INTO SOUTH CENTRAL AND THE MAT-SU SAT NIGHT
INTO EARLY SUNDAY. A LOW FORMING NEAR KODIAK ON SUNDAY WILL SLOW THE
PROGRESSION OF THE FRONT...KEEPING SNOW OVER THE AREA THROUGH SUN
NIGHT.

IN THE WEST...THE FRONT OVER THE BERING SLOWLY MOVES NORTHEAST BEFORE
WEAKENING SAT MORNING. THE REAL PLAYER OUT WEST IS THE LOW WELL SOUTH
OF ATTU. IT WILL RAPIDLY DEEPEN AS IT MOVES TO ADAK BY SAT AFTERNOON.
IT THEN WEAKENS THROUGH SUN NIGHT JUST NORTH OF ADAK. THE ASSOCIATED
OCCLUDED FRONT REACHES THE ALEUTIANS FRI NIGHT WITH STORMS...GALES...
AND RAIN. IT INTERACTS WITH RESIDUAL MOISTURE FROM THE PREVIOUS FRONT
OVER THE EASTERN BERING SAT AFTERNOON...BRINGING LIGHT SNOW INTO
SOUTHWEST ALASKA SAT AFTERNOON THROUGH SUN NIGHT. IT LOOKS AT THIS
POINT AS IF A SHORTWAVE SUN WILL ALLOW ENOUGH WARMING OVER BRISTOL
BAY FOR A CHANGEOVER TO RAIN.

IN THE EXTENDED...A MAJOR CHANGE IN THE 00Z GFS WAS DISCOUNTED AND
THE FORECAST LEANS HEAVILY TOWARD EARLIER MODELS RUNS...WHICH DO NOT
BRING ANY EXPLOSIVELY DEEPENING LOW TOWARD THE GULF COAST. THE
GENERAL IDEA...HOWEVER...IS THAT SOUTHWEST FLOW INTO THE NORTH GULF
COAST AND ADJACENT AREAS WILL PERSIST INTO NEXT WEEK WITH LIGHT SNOW
CONTINUING AT LEAST INTO MON BEFORE SOME WARMING FINALLY MOVES
INLAND. ALTHOUGH THE UPPER LEVEL PATTERN APPEARS TO BE CHANGING EARLY
NEXT WEEK...WITH THE UPPER TROUGH RETURNING TO THE STATE...THERE IS
SOME QUESTION AS TO WHETHER COLD AIR STREAMING SOUTH ALONG THE
WESTERN FLANK OF THE TROUGH WILL BE ABLE TO INDUCE STRONG
CYCLOGENESIS IN THE NORTHERN GULF. AT THIS POINT IT LOOKS LIKE SOME
WILL OCCUR...AND WILL KEEP ONSHORE FLOW IN PLACE.

IN THE WEST...THE LOW SPINS ITSELF OUT BY MONDAY AND IS REPLACED BY
COLD ADVECTION. THE MIX OF RAIN AND SNOW THROUGH THE WEEKEND WILL
BECOME SNOW SHOWERS ON NORTHWEST FLOW FOR NEXT WEEK. THE ONLY
QUESTION TO BE DETERMINED BY ADDITIONAL MODEL RUNS IS HOW MUCH COLD
AIR WILL FLOW ACROSS THE BERING AND SOUTHWEST ALASKA DURING THE WEEK.
AT THIS POINT THE FORECASTS LEAN TOWARD LESS RATHER THAN MORE.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE
MARINE...
       HEAVY FREEZING SPRAY IN AREAS 2B1 2C 2C4 3A 3C 4 6A 14
       GALES IN AREAS 3B 5A 5B 6A 6B 8 12A 12A1 13A 13B 14 15
       STORMS IN AREAS 3C 12B
FIRE WEATHER...NONE

DS FEB 05