Gale Warning 703, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
300 PM ADT WED SEP 27 2006

.DISCUSSION...
THE MAIN UPPER LEVEL LOW IS CENTERED OVER THE NORTHERN BERING SEA
WITH A TROUGH EXTENDING TO A SECOND LOW JUST SOUTH OF ADAK. A STRONG
150 KT JET IS WRAPPED AROUND THE SOUTH END OF THIS TROUGH. SATELLITE
IMAGERY INDICATES A DECENT MOISTURE FEED ALONG THE JET HEADING TOWARD
THE NORTH GULF COAST. THIS IS THE MOISTURE ASSOCIATED WITH THE
REMNANTS OF TYPHOON YAGI. A FRONTAL WAVE IS EVIDENT IN THE SATELLITE
ALONG WITH THE LOW ALREADY IN PLACE NEAR SAND POINT. THE FRONTAL WAVE
AND THE SAND POINT LOW ARE EXPECTED TO MERGE AND MOVE INTO WESTERN
PRINCE WILLIAM SOUND LATE TONIGHT. THE PARENT SURFACE LOW WHICH IS
THE REMNANTS OF YAGI WILL CONTINUE MOVING TO THE EAST REMAINING SOUTH
OF THE ALEUTIANS AS IT WEAKENS. THIS LOW SHOULD BE JUST SOUTH OF
KODIAK ISLAND THURSDAY NIGHT WITH THE REMAINS OF THE PRINCE WILLIAM
SOUND LOW DISSIPATING TO A WEAK TROUGH.

OVER THE EASTERN MAINLAND CURRENT CONDITIONS ARE THE RESULT OF THE
MOISTURE REMAINING IN THE AREA FROM THE LOW THAT MOVED INTO SOUTH
CENTRAL ALASKA YESTERDAY AND THE ASSOCIATED UPPER LEVEL TROUGH. THE
UPPER LEVEL TROUGH IS PUSHING INTO THE CANADIAN YUKON WITH WEAK
RIDGING BEHIND THIS. THIS SHOULD RESULT IN A VERY BRIEF PERIOD OF
DRIER CONDITIONS THIS EVENING. THE NEXT UPPER TROUGH AND THE SURFACE
MOISTURE NOW IN THE NORTH PACIFIC RAPIDLY MOVING OVER KODIAK WILL
MOVE INTO SOUTH CENTRAL ALASKA TONIGHT. THIS WILL BRING MORE RAIN TO
THE REGION TONIGHT AND THURSDAY.

FOR WESTERN ALASKA THE DOMINANT UPPER LOW OVER THE BERING STRAIT WILL
CONTINUE TO ROTATE CLOUDS AND MOISTURE INTO WESTERN ALASKA. WHILE THE
FLOW ALOFT WILL PERSIST FROM THE WEST A WEAK RIDGE OF HIGH PRESSURE
AT THE SURFACE WILL NOSE INTO THE NUNIVAK ISLAND AREA. WEAK LOW LEVEL
COLD ADVECTION INTO THE DELTA SHOULD RESULT IN KEEPING THE CLOUDS A
BIT HIGHER AND INHIBIT THE DEVELOPMENT OF FOG LIMITING THE FOG TO LOW
LYING INLAND AREAS. THE ONLY DIFFERENCE OF SIGNIFICANCE FROM THE
PREVIOUS FORECAST PACKAGE AT THIS TIME IS STRONGER WIND AVER THE
ALEUTIANS FRIDAY AND SATURDAY.

IN THE LONGER TERM THE TROUGH AND LOW IN THE GULF AND OVER THE
MAINLAND WILL MOVE EAST AS A RIDGE OF HIGH PRESSURE BUILDS FROM THE
NORTH PACIFIC INTO THE BERING SEA FRIDAY. THIS RIDGE WILL MOVE OVER
THE MAINLAND LATE FRIDAY AS A LARGE DEEP LOW MOVES INTO THE WESTERN
BERING SEA. THIS LOW WILL SLOWLY MOVE EAST ACROSS THE BERING SEA
THROUGH MONDAY DRAGGING THE COLD AIR FROM THE ASIA INTO THE WESTERN
BERING SEA.

COASTAL HAZARD POTENTIAL DAY 3 AND 4...NONE.
HYDROLOGY...NONE.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE ZONE 350.
FIRE WEATHER...DONE.

SAM SEP 06