000
FXAK68 PAFC 272345
AFDAFC
AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
400 PM AKDT WED AUG 27 2008
.MODEL DISCUSSION...
MODELS ARE IN GOOD AGREEMENT OVER THE BERING SEA THROUGH FRIDAY NIGHT
THEN BEGIN TO DIVERGE SATURDAY. BOTH GFS AND THE EUROPEAN MODELS MOVE
THE BERING LOW TO NEAR THE PRIBILOFS BY SATURDAY WHILE THE NAM KEEPS
THE MAIN CENTER CLOSER TO SAINT MATTHEW ISLAND. THE NEW MODELS HAVE
SLOWED EASTWARD MOVEMENT OF THE COLD FRONT ALONG THE WEST COAST AND
IS DISSIPATING IT FASTER THAN PREVIOUS RUNS.
MODELS CONTINUE TO BE IN VERY GOOD AGREEMENT OVER MAINLAND ALASKA AND
THE GULF.
.ANALYSIS AND UPPER LEVELS...
THE MAIN UPPER TROUGH OVER THE EASTERN BERING SEA CONTINUES TO MOVE
EAST TOWARD MAINLAND ALASKA. THE UPPER LOW OVER NORTHWEST CANADA IS
DRIFTING EAST.
AT THE SURFACE...A LARGE AREA OF LOW PRESSURE COVERS MOST OF MAINLAND
ALASKA. ANOTHER LOW PRESSURE SYSTEM IS MOVING OUT OF EASTERN RUSSIA
INTO THE BERING SEA. A SURFACE RIDGE LIES OVER THE EASTERN BERING.
.SHORT TERM FORECAST...
UPPER LEVELS...TROUGH OVER THE EASTERN BERING WILL CONTINUE TO MOVE
EAST AND WEAKEN OVER THE SOUTHWEST INTERIOR THURSDAY AND WILL
DISSIPATE THURSDAY NIGHT. A WEAK UPPER RIDGE OVER THE CENTRAL BERING
SEA WILL INTENSIFY AS IT MOVES INTO BRISTOL BAY AND THE KUSKOKWIM
DELTA THURSDAY NIGHT AND INTO THE GULF AND EASTERN MAINLAND SATURDAY.
AT THE SURFACE...THE BROAD AREA OF LOW PRESSURE OVER MAINLAND ALASKA
RECEDE TO THE EAST AS THE RIDGE OF HIGH PRESSURE OVER THE EASTERN
BERING MOVES EAST THROUGH MAINLAND ALASKA AND WEAKENS THROUGH
SATURDAY. THE LOW PRESSURE SYSTEM COMING OUT OF RUSSIA WILL MOVE TO
NEAR THE PRIBILOFS BY SATURDAY.
SOUTHCENTRAL ALASKA AND THE GULF...CLOUDS AND SHOWERS WILL PERSIST
OVER SOUTHCENTRAL ALASKA THROUGH THURSDAY EVENING. SKIES WILL BEGIN
TO CLEAR FROM THE WEST LATE THURSDAY NIGHT AND FRIDAY. MORE CLOUDS
WILL MOVE INTO KODIAK ISLAND AND THE WESTERN GULF FRIDAY NIGHT
FOLLOWED BY RAIN ON SATURDAY.
SOUTHWEST ALASKA...THE REMAINS OF THE COLD FRONT WILL MOVE EAST AND
DISSIPATE OVER THE SOUTHWEST INTERIOR THURSDAY NIGHT. CLOUDS AND
SHOWERS WILL PERSIST OVER THE EASTERN KUSKOKWIM VALLEY AND EASTERN
BRISTOL BAY THROUGH THURSDAY. SKIES WILL START TO CLEAR ALONG THE THE
BERING SEA COAST AND THE KUSKOKWIM DELTA TONIGHT AND THURSDAY AND
WILL SPREAD TO THE KUSKOKWIM VALLEY FRIDAY. MORE CLOUDS AND RAIN WILL
MOVE INTO THE KUSKOKWIM DELTA AND WESTERN BRISTOL BAY LATE THURSDAY
NIGHT AND FRIDAY AND WILL CONTINUE TO SPREAD INTO THE REST OF THE
AREA BY EARLY SATURDAY.
BERING SEA AND ALEUTIANS...
THE LOW PRESSURE SYSTEM DROPPING THROUGH THE BERING SEA OVER THE NEXT
FEW DAY WILL SPREAD RAIN THROUGH THE EASTERN BERING AND THE CENTRAL
AND EASTERN ALEUTIANS THROUGH FRIDAY. RAIN WILL CHANGE TO SHOWERS
SATURDAY.
.LONG TERM FORECAST...
THE UPPER RIDGE OVER THE EASTERN MAINLAND SATURDAY WILL MOVE INTO
WESTERN CANADA MONDAY. AN UPPER LOW DEVELOPING SOUTH OF THE EASTERN
ALEUTIANS SATURDAY NIGHT WILL MOVE INTO THE GULF SUNDAY NIGHT. A WEAK
UPPER LOW OR TROUGH WILL REMAIN OVER THE EASTERN BERING SEA THROUGH
THE LABOR DAY WEEKEND.
CLOUDS AND RAIN WILL CONTINUE TO SPREAD EAST INTO SOUTHCENTRAL ALASKA
AND THE GULF SUNDAY AND MONDAY. RAIN OVER SOUTHWEST ALASKA WILL
BECOME SHOWERS. SHOWERS WILL PERSIST OVER THE BERING SEA.
.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...NONE.
FIRE WEATHER...NONE.
NM AUG 08
