Small Craft Advisory 866, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 AM ADT WED OCT 26 2005

.DISCUSSION...

UPPER LEVEL LOWS OVER THE GULF OF ALASKA AND KAMCHATKA THIS
MORNING...WITH A SUBSTANTIAL RIDGE OVER THE CENTRAL BERING. THESE
FEATURES ARE VERTICALLY STACKED OVER SURFACE LOWS IN THE NORTHERN
GULF AND KAMCHATKA...AND HIGH PRESSURE OVER THE EASTERN BERING.
SHOWERS ARE COMMON OVER THE EASTERN HALF OF THE GULF AND OVER THE
NORTHERN SUSITNA VALLEY...WHILE A FRONT IS MOVING INTO THE EXTREME
WESTERN BERING.

MODELS ARE IN GOOD AGREEMENT IN CALLING FOR A PATTERN SHIFT BEGINNING
TONIGHT. THE KAMCHATKA LOW WILL UNDERCUT THE BERING RIDGE...WITH THE
RIDGE REBUILDING OVER KAMCHATKA FRI AFTERNOON AND EXPANDING OVER THE
WESTERN BERING FRI NIGHT. MEANWHILE...THE UNDERCUTTING LOW WILL MERGE
INTO A BROAD AREA OF LOW PRESSURE OVER THE STATE AND GULF.

AT THE SURFACE...LOW PRESSURE OVER THE NORTHERN GULF WILL WEAKEN INTO
A BROAD TROUGH WITH MOST OF THE ENERGY DRIFTING SOUTHEAST. THIS
SHOULD CLEAR OUT AREAS SOUTH AND EAST OF THE ALASKA RANGE TODAY AND
TONIGHT. NORTHEAST FLOW OVER AREAS WEST OF THE RANGE SHOULD ALSO
DIMINISH...ESPECIALLY TONIGHT AS THE EASTERN BERING RIDGE BUILDS INTO
WESTERN ALASKA. THE FRONT ASSOCIATED WITH THE UNDERCUTTING KAMCHATKA
LOW WILL BRING GALES TO THE WESTERN HALF OF THE ALEUTIANS THROUGH THU
NIGHT AS IT MAKES ITS WAY EAST.

AS THE WEEKEND APPROACHES...RIDGING OVER THE WESTERN BERING WILL
DEVELOP AND THE BROAD AREA OF CYCLONIC FLOW WILL EXTEND FROM THE
AKPEN TO THE NORTHEAST GULF COAST. THIS WILL PRODUCE SHOWERS OVER THE
AKPEN. AS THE FRONT CROSSING THE ALEUTIANS WEAKENS...GALES WILL
FOLLOW OVER MUCH OF THE CHAIN. WEAK RIDGING WILL DOMINATE THE
MAINLAND AREAS.

IN THE EXTENDED...THE RIDGE OVER THE BERING WILL MIGRATE TO THE
CANADIAN ROCKIES BY THE MIDDLE OF NEXT WEEK. THE SURFACE LOW OVER THE
STATE WILL CONSOLIDATE AND MOVE INTO SOUTHEAST ALASKA BY MON WITH
MOST PRECIP REMAINING ALONG THE COAST OR FURTHER SOUTH. THE NEXT
KAMCHATKA LOW AND ASSOCIATED FRONT WILL BRING GALES AND STORMS TO THE
WESTERN BERING SUN AND REACH SOUTHWEST ALASKA WITH STRONG WINDS AND
AN OVERRUNNING SNOW CHANGING INTO RAIN PRECIPITATION EVENT LATE MON
INTO TUE. THE ORIENTATION OF THIS SYSTEM POINTS TOWARD TURNAGAIN ARM
WINDS FOR THE MIDDLE OF NEXT WEEK.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE
MARINE...GALES 172 175 176 185
FIRE WEATHER...NONE

DS OCT 05