High Wind Watch 6, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 AM AKST TUE FEB 24 2009

CORRECTION FOR TYPO

.ANALYSIS AND UPPER LEVELS...

A POSITIVELY TILTED UPPER RIDGE EXTENDS ACROSS THE THE GULF AND ALCAN
TOWARD EXTREME NORTHWESTERN CANADA THIS MORNING. A MASSIVE UPPER LOW
OVER SIBERIA IS SPINNING OFF SHORTWAVES THAT ARE FOLLOWING A
TRAJECTORY FROM SOUTH OF KAMCHATKA TO THE BERING STRAIT. AT THE
SURFACE...A RIDGE OF HIGH PRESSURE CENTERED WELL SOUTH OF DUTCH
HARBOR EXTENDS OVER ALL OF MAINLAND AK. A WEAK TROUGH OF LOW PRESSURE
IS OVER THE NORTH GULF COAST. A DISSIPATING LOW IS OVER THE NORTHERN
GULF WHILE THE MAIN LOW IS SOUTH OF THE WESTERN ALEUTIANS.

.MODEL DISCUSSION...

MODELS HAVE COME INTO VERY GOOD AGREEMENT OVER THE LAST SEVERAL RUNS.
THEY ALL BRING THE WEATHER MAKING LOW ACROSS THE CENTRAL ALEUTIANS
THIS AFTERNOON AND TO THE Y-K DELTA BY WED AFTERNOON. BECAUSE OF THE
PRESSURE DIFFERENCE BETWEEN A ROUGHLY 987 MB LOW MOVING ACROSS THE
BERING AND THE 1043 MB HIGH TO THE SOUTHEAST...HURRICANE FORCE AND
STORM FORCE WINDS WILL BE AFFECTING THE BERING AND ALEUTIANS FOR THE
NEXT COUPLE OF DAYS. THE GFS HAS BEEN SHOWING EXCELLENT CONSISTENCY
AND FORMS THE BASIS FOR TODAY'S FORECAST.

.SHORT TERM FORECAST...

IN THE WEST...HURRICANE FORCE AND STORM FORCE WINDS WILL AFFECT THE
WESTERN AND CENTRAL BERING AND ALEUTIANS TODAY...AND THE REST OF THE
AREA TONIGHT. SNOW AND BLOWING SNOW WILL ALSO BE ISSUES...ALTHOUGH
WARMING ON THE EAST SIDE OF THE LOW AS IT TRANSITS THE REGION WILL
BRING A HEALTHY ROUND OF RAIN TO THE PRIBILOFS THROUGH THIS EVENING
BEFORE SWITCHING TO SNOW SHOWERS WITH DANGEROUS WINDS ON THE BACK
SIDE OF THE SYSTEM. SNOW SHOWERS WILL PERSIST ACROSS THE AREA INTO
WED WHEN A FRONT FROM A KAMCHATKA LOW BRINGS STORMS AND RAIN TO THE
WESTERN CHAIN. THE LOW MIGRATES TO THE EAST...BRINGING WARM AND WINDY
CONDITIONS TO THE CENTRAL AND THEN EASTERN ISLANDS INTO FRI.

FOR SOUTHWEST AK...A DECAYING WEATHER FRONT WILL BRING A FEW SNOW
SHOWERS TO THE AREA TODAY...WITH A LULL UNTIL THE FIRST BAND OF WIND
AND RAIN/SNOW REACH THE COAST LATE TONIGHT AND MOVE INLAND. THE
KUSKOKWIM DELTA MAY EXPERIENCE BLIZZARD CONDITIONS TONIGHT ALONG THE
COAST UNTIL WARMER AIR ARRIVES BRIEFLY ON WED. THIS WILL BE OF SHORT
DURATION AS STRONG WINDS AND SNOW SHOWERS MOVE ACROSS THE AREA WED
MORNING THROUGH THU MORNING. AT THAT TIME A RIDGE REACHES THE COAST
AND SHUTS OFF THE WIND AND SHOWERS UNTIL FRI. THE WEATHER FRONT FROM
THE KAMCHATKA LOW THEN BRINGS WIND AND SNOW BACK TO THE AREA ON FRI.

SOUTH AND EAST OF THE AK RANGE...CONDITIONS WILL REMAIN DRY UNTIL A
WEAK IMPULSE BRINGS SOME SNOW SHOWERS TO THE REGION WED EVENING. ON
THU REMNANTS OF THE INITIAL LOW THAT WENT INLAND IN THE Y-K DELTA
WILL SPREAD SOME SNOW SHOWER ACROSS THE AREA BEFORE RIDGING DRIES
THINGS OUT FOR FRI.

.LONG TERM FORECAST...

SNOW SHOWERS CAN BE EXPECTED IN THE WEST INTO SAT WHEN ANOTHER A LOW
PARALLELING THE KAMCHATKA COAST WILL BRING WARM SOUTH FLOW TO THE
BERING WITH SNOW CHANGING TO RAIN INTO MON. SNOW SHOWERS ON WEST FLOW
WILL PERSIST OVER SOUTHWEST AK INTO MON. SOUTHEAST OF THE AK
RANGE...REMNANTS OF THE KAMCHATKA FRONT WILL BRING SOME SNOW TO THE
AREA FOR THE WEEKEND THAT SHOULD DIMINISH MON AS HIGH PRESSURE
RETURNS.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...155 BLIZZARD WATCH
         187 HIGH WIND WARNING
         191 BLIZZARD WARNING
         195 HIGH WIND WATCH
MARINE...HURRICANE FORCE WIND WARNING 172 175 179
         STORMS 160 165 170 176 180 185
         GALES 155 171
         HEAVY FREEZING SPRAY 185
FIRE WEATHER...NONE

DS FEB 09