Gale Warning 122, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
200 PM AKST FRI FEB 13 2009

.MODEL DISCUSSION...MODEL SHORT TERM SOLUTIONS AND FORECAST TRENDS
SEEM REASONABLE THROUGH ABOUT SUN NIGHT. SOLUTIONS VARY SIGNIFICANTLY
BEYOND THIS PONIT OVER THE ALEUTIANS/BERING SEA.

.UPPER LEVELS...PROGRESSIVE PATTERN CONTINUES. BROADENING UPPER
CENTER OVER EASTERN RUSSIA ACTS AS THE PIVOT POINT FOR DEVELOPING
WAVES MOVING ACROSS ASIA/NORTH PACIFIC INTO THE BERING SEA/ALEUTIANS
AND SW MAINLAND. THIS WILL TRANSLATE INTO CONTINUED UNSETTLED WEATHER
WITH ALTERNATE STORM SYSTEMS OUT WEST. CONDITIONS IN THE EAST AND
SOUTHCENTRAL SHOULD NOT BE AS TURBULENT WAS LOW AMPLITUDE RIDGES
TRANSIT THE AREA.

.SHORT TERM FORECAST...
.EAST...FRONTAL TROUGH OVER THE WESTERN GULF WILL SLOWLY PROGRESS
EAST AS UPPER TROUGH MOVES ACROSS SOUTHCENTRAL ALASKA LATE TONIGHT
AND SAT. SO WILL INCREASE POPS ACROSS MUCH OF SOUTHCENTRAL TONIGHT.
GAP WINDS SHOULD DIMINISH OVER MUCH OF SOUTHCENTRAL OVERNIGHT AS
PRESSURE GRADIENTS RELAX. WINDS ARE EXPECTED TO INCREASE AGAIN ACROSS
SOUTHCENTRAL AND THE GULF SAT NIGHT/SUN AS A STRONG FRONTAL TROUGH
MOVES TO THE WESTERN GULF OF ALASKA. IT LOOKS THIS ONE WILL BRING
MUCH WARMER AIR SO INITIAL BURST OF SNOW SHOULD CHANGE TO RAIN OVER
THE WESTERN GULF SUN AFTERNOON AND BECOME MIXED OVER THE KENAI
PEN/PORTIONS OF THE NORTH SUN AFTERNOON/NIGHT.

.WEST...STORM CENTER NEAR ST. MATTHEW ISLAND CONTINUES TO WEAKEN AND
MOVES OVER THE SEWARD PEN TONIGHT. ASSOCIATED FRONTAL TROUGH AT
STRETCHING ACROSS THE SW MAINLAND IS WEAKENING. RADAR AND SATELLITE
SHOW THE BACK EDGE OF RAIN/SNOW APPROACHING THE SW COAST.
PRECIPITATION SHOULD BECOME MORE SHOWERY TONIGHT ON TH BACKSIDE OF
TROUGH. NEXT BIG STORM DEVELOPING SW OF THE ALEUTIANS MOVES SOUTH OF
ADAK SAT MORNING AND SOUTH OF THE PRIBILOFS SUN NIGHT. THIS CENTER
THEN WEAKENS AND MOVES TO ALONG THE SW COAST NEAR BETHEL SUN
AFTERNOON. THE CENTRAL AND EASTERN ALEUTIANS WILL SEE BRIEF PERIODS
OF BLOWING SNOW TONIGHT AND THE AK PEN SAT UNTIL THE WARM AIR MOVES
IN AND MIXES OR CHANGES THE SNOW TO RAIN. BLIZZARD CONDITIONS LIKELY
OVER THE WESTERN ALEUTIANS EARLY SAT MORNING WITH STRONG WINDS AND
COLD ADVECTION ON THE BACKSIDE OF THE OCCLUDED FRONT/LOW CENTER.
THESE CONDITIONS MAY SPREAD EAST ACROSS THE ALEUTIANS AS LOW CENTER
MOVES TOWARD THE PRIBILOFS. BLIZZARD CONDITIONS ARE ALSO PROBABLE
OVER THE PRIBILOFS LATE TONIGHT WITH SNOW AND WIND DEVELOPING IN
ADVANCE OF FRONT. TEMPS SHOULD WARM ENOUGH TO END BLIZZARD CONDITIONS
IN THE PRIBILOFS SAT EVENING...BUT MAY REDEVELOP SUN MORNING WITH THE
ONSET OF COLD ADVECTION ON THE BACKSIDE OF LOW. TEMPS WILL BE SLOW TO
WARM OVER THE SW MAINLAND...SO WILL SEE SOME BLOWING SNOW DEVELOPING
SAT NIGHT...THIS WILL BEAR WATCHING FOR BLIZZARD POTENTIAL.

.LONG TERM FORECAST...
THE LONG-WAVE PATTERN REMAINS LOW AMPLITUDE AND PROGRESSIVE INTO NEXT
WEEK. THE RESULTANT STORM TRACKS WILL CONTINUE TO MOVE QUICKLY ACROSS
THE FORECAST AREA. THE NEXT NORTH PACIFIC LOW IS ALREADY FORMING AND
WILL AFFECT THE ALEUTIANS LATE THIS WEEKEND.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...BLIZZARD WARNING 191 AND BLIZZARD WATCH 195.
MARINE...STORM 172 AND 175
GALES 130 150 155 160 165 170 171 176 179 185.

RMC FEB 09