High Wind in Alaska, March 19, 2011

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
500 AM AKDT SAT MAR 19 2011

.ANALYSIS AND UPPER LEVELS...THE LARGE LOW THAT HAS DOMINATED THE
BERING SEA FOR DAYS IS BECOMING A DISTANT MEMORY AS IT WEAKENS
RAPIDLY AND DRIFTS NORTH INTO SIBERIA. HOWEVER THIS LULL IN ACTIVE
WEATHER WILL BE SHORT LIVED AS RAPIDLY STRENGTHENING AND FAST-MOVING
979 MB LOW IS APPROACHING THE EASTERN BERING SEA FROM THE NORTH
PACIFIC. THIS LOW IS DRAWING ENERGY FROM A 175 KT JET STREAK MOVING
THROUGH THE SUBTROPICAL JET SOUTH OF THE ALEUTIANS. AHEAD OF THIS LOW
IS A HIGH AMPLITUDE RIDGE THAT IS MAKING FOR A PLEASANT MORNING OVER
VIRTUALLY ALL OF MAINLAND ALASKA.

.MODEL DISCUSSION...MODELS ARE IN GOOD SYNOPTIC AGREEMENT WITH THIS
RAPIDLY DEVELOPING LOW. MODEL SOLUTIONS REGARDING THE INTENSITY OF
THIS LOW THROUGH THE NEXT DAY OR TWO ARE ALSO CLOSELY ALIGNED.
NEVERTHELESS THERE REMAINS SOME DIFFERENCES THAT REMAIN REGARDING HOW
QUICKLY THIS LOW MOVES INTO THE EASTERN AND THEN NORTHERN BERING SEA
TONIGHT AND SUNDAY. THE EC AND NAM ARE A BIT SLOWER THAN THE
GFS...WHICH IS A BIT OF AN OUTLIER THIS MORNING AND HAS BEEN LARGELY
EXCLUDED FROM THE MORNING FORECAST. OVERALL MODEL CONFIDENCE IS
AVERAGE THIS MORNING.

.SHORT TERM FORECAST...THE NORTH PACIFIC LOW RAPIDLY MOVING INTO THE
FORECAST DOMAIN IS THE PRIMARY FORECAST CHALLENGE TODAY. WHILE THIS
LOW IS NOT AS STRONG AS THE LOW EARLIER THIS WEEK...IT IS COMING INTO
CLOSER CONTACT WITH THE RIDGE OF HIGH PRESSURE THAT HAS RESIDED OVER
MAINLAND ALASKA FOR THE LAST 3 WEEKS. THIS WILL ALLOW THE PRESSURE
GRADIENT TO BECOME SIGNIFICANTLY ENHANCED OVER THE EASTERN ALEUTIANS
AND ALASKA PENINSULA TODAY. COMBINED WITH THE COMPLEX TERRAIN IN
THESE AREAS IT SEEMS LIKELY WE WILL SEE SEVERAL LOCATIONS WITH WINDS
ABOVE HURRICANE FORCE. WORST CONDITIONS ARE EXPECTED BETWEEN DUTCH
HARBOR AND COLD BAY BEGINNING BY LATE THIS MORNING AND CONTINUING
THROUGH THE NIGHT. BECAUSE THIS LOW IS MOVING SO FAST...WIND
DIRECTIONS WILL BE CHANGING QUICKLY ESPECIALLY AROUND DUTCH
HARBOR...WHERE STRONG SOUTHEAST WINDS WILL BE QUICKLY REPLACED BY
EQUALLY STRONG WESTERLY WINDS BY MIDNIGHT TONIGHT.

FURTHER NORTH...COASTAL SECTIONS OF SOUTHWEST ALASKA WILL BEAR THE
BRUNT OF THE HIGH WINDS...THOUGH INTERIOR SECTIONS WILL STILL SEE
STRONG GUSTS THAT LINGER THROUGH SUNDAY MORNING. MOST PRECIPITATION
WILL ALSO BE LIMITED TO THE COAST. WITH TEMPERATURES NEAR FREEZING A
MIX OF RAIN AND SNOW IS LIKELY ACROSS THE REGION WITH ONLY MINOR
ACCUMULATIONS EXPECTED.

EAST OF THE ALASKA RANGE...MAIN IMPACT WILL BE SUNNY SKIES TODAY
REPLACED BY INCREASING CLOUDINESS TOMORROW. RAIN WILL ARRIVE IN
KODIAK ISLAND BY TOMORROW MORNING...MIXING WITH SNOW AND SPREADING TO
THE EASTERN KENAI PENINSULA BY SUNDAY EVENING.

.LONG TERM FORECAST...PROGRESSIVE WEATHER PATTERN STILL ON TRACK TO
TAKE HOLD OF MUCH OF THE STATE FOR THE COMING WEEK. MODELS ARE
BEGINNING TO SUGGEST THAT THE MOST ACTIVE WEATHER MAY BE CONFINED TO
THE BERING SEA AND THE SOUTHERN GULF OF ALASKA. TEMPERATURES ACROSS
THE ENTIRE DOMAIN WILL REMAIN NEAR SEASONAL NORMS WITH PERIODS OF
SUNSHINE OVER MAINLAND ALASKA.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...HIGH WIND WARNING 181 185
MARINE...HURRICANE FORCE WIND WARNING 155 170
         STORM WARNING 150 160 165 171 172
         GALE WARNING 175 176 179 180
FIRE WEATHER...NONE

AMD MAR 11