Storm Warning 189, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
400 PM AKDT THU OCT 14 2010

.MODEL DISCUSSION...MODEL RUNS FROM 12Z ARE CONSISTENT WITH EACH
OTHER AND WITH PREVIOUS RECENT RUNS. THE 18Z NAM IS GOING OFF WITH A
MORE SOUTHERLY TRACK FOR THE BERING SEA LOW THIS WEEKEND BUT THERE IS
NO SUPPORT FOR THIS TRACK AND IT IS LIKELY THAT IT WILL RETURN BACK
TO THE NORTHERN TRACK ON THE 00Z RUN.

.ANALYSIS AND UPPER LEVELS...UPPER LEVEL TROUGH HAS MOVED ALONG THE
ALCAN BORDER AND THE UPPER RIDGE IN THE BERING SEA HAS FLATTENED
CAUSING ZONAL FLOW OVER THE BERING SEA AND INTO THE GULF OF ALASKA.
AN UPPER LEVEL LOW WILL DIG INTO THE ZONAL FLOW OVER THE BERING SEA
FRI NIGHT AND THIS WILL CAUSE THE RAPID STRENGTHENING OF A SURFACE
LOW THAT IS CURRENTLY SOUTH OF KISKA. AS THE UPPER LEVEL TROUGH DIGS
SOUTHWARD A RIDGE WILL AMPLIFY OVER THE EASTERN HALF OF THE STATE.
THIS RIDGE WILL CAUSE THE SURFACE TO MOVE NEAR BRISTOL BAY AND THEN
ALMOST STOP AND REMAIN STATIONARY ON SATURDAY BEFORE HEADING
SOUTHEAST AND ACROSS THE AK PENINSULA SUNDAY.

.SHORT TERM FORECAST...WINDS ALONG THE NORTH GULF COAST WILL DIMINISH
AND BECOME LIGHT BY LATE THIS EVENING AS THE PRESSURE GRADIENT
DIMINISHES. FOG IS UNLIKELY TO FORM OVER SOUTH CENTRAL ALASKA AS THE
WINDS HAVE DRIED THE AIRMASS SINCE THE WIDESPREAD FOG ON TUESDAY.
SOME AREAS OF SNOW MAY PERSIST OVER THE KUSKOKWIM DELTA AND THE
WESTERN HALF OF THE BRISTOL BAY ZONE THIS EVENING AS A WEAKENING
SHORT WAVE MOVES ACROSS THE AREA. THE LOW THAT WILL DEVELOP INTO THIS
WEEKENDS BIG WEATHER MAKER CAN BE SEEN BEST ON THE IR SATELLITE SOUTH
OF KISKA.

.LONG TERM FORECAST...NEXT WEEKS WEATHER PATTERN WILL LIKELY SEE UN
UPPER LEVEL TROUGH BECOME ENTRENCHED OVER THE EASTERN BERING SEA AND
SOUTHWEST ALASKA AGAIN. THIS WILL BRING SNOW SHOWERS TO AREA TO THE
WEST OF IT AND A CHANCE FOR RAIN FOR AREA TO THE EAST. WHILE THERE
COULD BE SNOW MIXED INTO EASTERN AREA THAT WILL LIKELY BE JUST AT
HIGHER ELEVATIONS AND POSSIBLY THE COPPER RIVER BASIN.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE 155 160 165 170 171 175 176 179 180 185.
FIRE WEATHER...NONE.

OCT 10