Snow Advisory 3, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
200 PM AST THU NOV 9 2006

.DISCUSSION...
ALL MODELS HAVE DONE A GOOD JOB OF INITIALIZATION THIS MORNING. THE
MAJOR AND MINOR FEATURES ARE ALL REPRESENTED WELL WITHIN A COUPLE
MILLBARS OF EACH OTHER. NOT MUCH DIFFERENCE BETWEEN NAM AND GFS
THROUGH THE WEEKEND. ONLY DIFFERENCE WILL PROBABLY BE THAT A REMNANT
LOW WILL REMAIN IN THE NORTHERN GULF OF ALASKA THROUGH EARLY NEXT
WEEK. THIS SOLUTION DIFFERS FROM THE 12Z GFS SOLUTION. HOWEVER...THE
12Z GFS ENSEMBLES PICK UP ON THIS FEATURE WITH A STRONGER SURFACE
TROUGH THAN THE OPERATIONAL RUN. A LOW TO REMAIN IN THE GULF THROUGH
MID NEXT WEEK. HIGH PRESSURE TO BUILD OVER THE BERING SEA THROUGH THE
WEEKEND AND REMAIN IN PLACE INTO MID NEXT WEEK.

UPPER AIR...CURRENTLY...AN UPPER LOW IS PRESENT OVER SOUTHWEST ALASKA
WITH ANOTHER JUST SOUTH OF THE GULF. A RIDGE IS PRESENT OVER THE
WESTERN BERING. A STRONG SHORT WAVE IS DROPPING SOUTH BEHIND THE
SOUTHWEST ALASKA LOW WITH GOOD PUSH OF COLD AIR. A SURFACE LOW IS
DEVELOPING UNDERNEATH THE UPPER LOW JUST SOUTH OF THE GULF. THIS IS
BEING ENHANCED BY A STRONG JET RUNNING FOR 170W TO 130W ROUGHLY ALONG
45N. THE JET TO PUSH INTO THE PANHANDLE AS THE SURFACE LOW RECURVES
TO THE NORTH INTO THE GULF. THE ASSOCIATED UPPER LEVEL LOW TO RECURVE
AS WELL AND MERGE WITH THE SOUTHWEST ALASKA LOW FRIDAY AFTERNOON.
ANOTHER SHORT WAVE TROUGH ROTATING THROUGH SOUTH CENTRAL TONIGHT TO
SWING THROUGH SOUTHWEST ALASKA FRIDAY AND ACROSS THE ALEUTIAN CHAIN
FRIDAY NIGHT. HIGH PRESSURE THEN TO BUILD OVER THE ENTIRE BERING SEA
SATURDAY AS ANOTHER SHORT WAVE TROUGH DROPS IN FROM THE NORTH ACROSS
MUCH OF ALASKA. THIS FEATURE WILL ACT TO PUSH THE LOW OUT OF THE GULF
SUNDAY. IN ADDITION...A STRONG SHORT WAVE MOVES OUT OF THE POLAR LOW
OVER EASTERN ALASKA SUNDAY NIGHT WITH ANOTHER PUSHING OVER THE TOP OF
THE RIDGE IN THE WEST AND INTO WESTERN ALASKA MONDAY.

SURFACE WEST OF THE ALASKA RANGE...HIGH PRESSURE TO REMAIN OVER THE
WESTERN BERING THROUGH EARLY NEXT WEEK. THIS AREA OF HIGH PRESSURE TO
PUSH OVER THE ENTIRE BERING BY SUNDAY THEN RETREAT MONDAY. IN THE
MEANTIME...THE BIG CONCERN IS STRONG WINDS IN THE EASTERN BERING AND
ALONG THE WEST COAST OF ALASKA. THIS IS DUE TO A STRONG PRESSURE
GRADIENT PRESENT THERE THROUGH SATURDAY AND COLD AIR ADVECTION. THE
FIRST PUSH TO MOVE THROUGH WESTERN ALASKA AND THE EASTERN ALEUTIANS
TONIGHT AND TOMORROW. SOME SNOW TO ACCOMPANY THIS FEATURE AS WELL.
HOWEVER...GALE FORCE WINDS ARE EXPECTED TO BE THE MAIN PROBLEM OVER
THE EASTERN BERING THROUGH SATURDAY. ANOTHER WAVE TO CROSS THROUGH
SOUTHWEST ALASKA FRIDAY AFTER IT GOES THROUGH SOUTH CENTRAL TONIGHT.
THIS WILL BRING SOME BETTER SNOWFALL AMOUNTS TO AREAS ALONG THE
ALEUTIAN RANGE. WARMER AIR ASSOCIATED WITH THIS FEATURE AS WELL.
SO...AREAS WILL LIKELY WARM UP AFTER THIS FEATURE FRIDAY AFTERNOON.
COLD AIR WILL RETURN TO SOUTHWEST ALASKA BY SATURDAY. A WEAK LOW TO
PUSH THROUGH WESTERN ALASKA SUNDAY NIGHT AND MONDAY BEFORE ENTERING
THE GULF. AN AREA OF MODERATE TO STRONG WINDS AND MODERATE
PRECIPITATION TO ACCOMPANY THIS FAST MOVING FEATURE.

SURFACE EAST OF THE ALASKA RANGE...A DEVELOPING LOW JUST SOUTH OF THE
GULF TO MOVE NORTH TONIGHT AND INTO THE NORTHERN GULF FRIDAY
AFTERNOON. AHEAD OF THIS FEATURE...AN UPPER LEVEL WAVE BRINGING A
GOOD AMOUNT OF MOISTURE AND PRECIPITATION TO BEGIN SPREADING WEST
ACROSS THE NORTHERN GULF COAST THIS AFTERNOON. THE FEATURE WILL PUSH
PRECIPITATION AROUND SOUTH CENTRAL TONIGHT AND REACH KODIAK BY
TOMORROW MORNING.  AN AREA OF WARMER AIR ASSOCIATED WITH THIS WAVE AS
WELL. PRECIPITATION LIKELY TO CHANGE OVER TO RAIN AT CORDOVA LATER
TONIGHT AND WORK TO KODIAK BY TOMORROW AFTERNOON. KODIAK COULD SEE
SOME AREAS OF BLOWING SNOW FROM THIS FEATURE...BUT BELIEVE THE
STRONGEST WINDS TO BE ASSOCIATED WITH WARMER AIR AND A CHANGE OVER TO
ALL RAIN OR A MIX OF RAIN AND SNOW TOMORROW AFTERNOON. PRECIPITATION
WILL END IN THE EVENING OVER ALL OF SOUTH CENTRAL.

THE LOW IN THE GULF WILL DEEPEN THIS EVENING BEFORE DECOUPLING FROM
THE JET LATER TONIGHT. THE LOW WILL THEN CURVE TO THE NORTH AND
WEAKEN SLOWLY OVER THE NEXT COUPLE DAYS. THIS LOW CONTINUES A GOOD
NORTH SOUTH PRESSURE GRADIENT OVER SOUTH CENTRAL THROUGH MUCH OF THE
WEEKEND. THE STRONGEST GRADIENT TO BE ON FRIDAY NIGHT INTO EARLY
SATURDAY BEFORE THE LOW DROPS FARTHER SOUTH AND WEAKENS FURTHER IN
THE GULF. THE UPPER LEVEL SUPPORT NOT REALLY THERE FOR REALLY STRONG
WINDS UNTIL FRIDAY EVENING AND NIGHT. SO HAVE PUSHED OFF THE WATCH
UNTIL THAT TIME FRAME FOR THE COPPER RIVER DELTA. OTHER AREAS NOT
LIKELY TO SEE ANY WARNING LEVEL WINDS. HOWEVER...WITH THE DEPTH OF
THIS LOW WE WILL SEE GALE FORCE WINDS IN MANY AREAS TONIGHT THROUGH
FRIDAY NIGHT.

COLD AIR TO RETURN QUICKLY SATURDAY. HOWEVER...THE AIR MASS WILL BE
DRY AS WELL. EXPECT CLEAR AND COLD AIR MASS TO REMAIN OVER SOUTH
CENTRAL THROUGH EARLY NEXT WEEK. THE ONLY INTERRUPTION TO THIS WILL
BE ALONG THE NORTHERN GULF COAST WITH ONE LAST WEAK WAVE TO MOVE
AROUND THE LOW IN THE GULF SATURDAY BEFORE IT PUSHES TO THE PANHANDLE
SUNDAY. ANOTHER INTERRUPTION WILL BE THE PROGRESS OF A LOW MOVING OUT
OF THE NORTH ACROSS WESTERN ALASKA INTO THE KODIAK AREA BRINGING
ANOTHER SHOT OF SNOW TO THAT AREA. THIS FEATURE WILL REINSTATE A LOW
CENTER IN THE GULF BY TUESDAY.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...HIGH WIND WATCH ZONE 135
MARINE...GALE 120 132 138 150 155 165 170 171 172 179 180 185
FIRE WEATHER...NONE

JN NOV 06