Brisk Wind Advisory 12, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
1100 AM AST WED JAN 18 2006

.DISCUSSION...
NOW...LOW IN THE NORTHERN GULF OF ALASKA INITIALIZED OK BY MODELS.
MAY BE OFF A BIT...BUT NOT MUCH. OTHER AREAS SEEMS TO BE INITIALIZED
WELL. MOISTURE FIELD A LITTLER BETTER FIT WITH THE GFS THIS MORNING
PER WV IMAGERY. EITHER WAY...MODELS IN GOOD AGREEMENT GENERALLY. ONLY

MAJOR DIFFERENCE IS SPEED OF THE LOW ON SATURDAY AS IT MOVES INTO THE
GULF OF ALASKA. GFS IS FASTER THAN THE ETA AT THIS POINT. BASED UPON
THE 00Z ENSEMBLES...WOULD LEAN MORE TOWARDS THE ETA AT THAT POINT IN
THE FORECAST. HOWEVER...THE 12Z GFS ENSEMBLE MORE IN LINE WITH THE
12Z OPERATIONAL GFS.

UPPER LEVELS...STRONG UPPER LEVEL LOW OVER THE SOUTHERN TIP OF THE
KAMCHATKA PENINSULA WITH A DEEPENING LOW OVER THE CHUKCHI SEA. THE
CHUKCHI SEA LOW TO MOVE OVER THE MAINLAND AND SETTLE OVER THE STATE
BY THURSDAY AFTERNOON. SHORT WAVE TROUGH SOUTH OF THE CENTRAL
ALEUTIAN CHAIN WILL QUICKLY MOVE ACROSS THE GULF OF ALASKA TONIGHT.
ANOTHER SHORT WAVE ROUNDING THE KAMCHATKA LOW WILL MOVE TO THE
ALEUTIAN CHAIN THEN DISSIPATE THURSDAY WITH HIGH PRESSURE OVER THE
BERING SEA. MANY OTHER SHORT WAVE TROUGHS TO ROUND THE LOW OFF THE
KAMCHATKA STEALING ENERGY FROM THE MAIN LOW. THIS WILL WEAKEN THE
KAMCHATKA LOW AND FORM ANOTHER LOW TO THE SOUTHWEST BY SATURDAY. IN
ADDITION...COLD AIR FILTERING INTO THE BERING SEA ON THE BACKSIDE OF
THE MAINLAND LOW FRIDAY AND SATURDAY WILL ACT TO RETROGRADE THE LOW
TO BRISTOL BAY. THE COMBINATION OF THESE ACTIONS WILL RESULT IN A
RIDGE OVER THE WESTERN BERING SEA. AS THE LOW SOUTHWEST OF THE
KAMCHATKA BEGINS TO MOVE EAST SUNDAY AND MONDAY...THIS WILL MOVE THE
SYSTEMS DOWNSTREAM TO THE EAST AS WELL.

SOUTH CENTRAL SURFACE...WEAK SURFACE LOW NEAR THE SOUND WILL MOVE
INTO THE SOUND TONIGHT. SCATTERED SHOWERS WRAPPING AROUND THE WEAK
LOW. AS THE LOW MOVES INTO THE SOUND...SHOWERS TO MAKE THEIR WAY OVER
THE MOUNTAINS AND INTO THE ANCHORAGE BOWL...MATANUSKA VALLEY AND UP
THE TALKEETNA MOUNTAINS AND POINTS EAST. ONLY EXPECTING LIGHT AMOUNTS
AT THIS TIME. BUT IF THE LOW PICKS UP MORE MOISTURE...COULD SEE A FEW
MORE INCHES. THE EVENT WILL BE SHORT LIVED AS THE UPPER LEVEL TROUGH
WILL SWEEP IN DRIER AND COLDER AIR THURSDAY. TEMPS WILL BE 5 TO 10
DEGREES BELOW NORMAL THURSDAY AND FRIDAY. THE TROUGH WILL SWEEP
MOISTURE TO THE EAST OF MOST AREAS. HOWEVER...ENOUGH MOISTURE AND THE
SURFACE TROUGH WILL REMAIN IN THE GULF FOR SNOW ALONG THE COAST AND
EASTERN COPPER RIVER BASIN. A WEAK LOW WILL MOVE INTO THE WESTERN
GULF FRIDAY WITH A FRONT RACING TO THE PANHANDLE LATE FRIDAY. THIS IS
AHEAD OF A STRONGER LOW WHICH WILL SOUTH OF DUTCH HARBOR FRIDAY
NIGHT. THIS LOW WILL WORK INTO THE GULF SATURDAY WITH STRONG WINDS
AND PLENTY OF PRECIPITATION REACHING THE ENTIRE GULF. TEMPS WILL WARM
UP INTO THE WEEKEND AS THIS LOW MOVES NORTH IN THE WESTERN GULF.

WEST OF THE ALASKA RANGE SURFACE...HIGH PRESSURE AT THE SURFACE OVER
EASTERN RUSSIA WITH A LOW TO THE SOUTH OF THE WESTERN ALEUTIAN CHAIN.
THIS IS RESULTING IN A STRONG PRESSURE GRADIENT OVER MUCH OF THE
BERING SEA AND ALEUTIAN CHAIN. STRONG WINDS ARE BEING REPORTED FROM
THE ALASKA PENINSULA WEST. COLD AIR BEING FILTERED THROUGH THESE
AREAS AS WELL WITH HEAVY FREEZING SPRAY IN MANY AREAS OVER THE BERING
OFFSHORE AND EXTREME EASTERN ALEUTIAN CHAIN. TEMPERATURES ARE ROUGHLY
5 TO 10 DEGREES BELOW NORMAL OVER THE EASTERN ALEUTIANS TO 15 TO 20
DEGREES BELOW NORMAL INLAND. THE HIGH PRESSURE TO REMAIN OVER THE
AREA EVEN THOUGH A LOW IS WORKING TO ADAK THURSDAY. THE LOW REMAINS
SOUTH OF THE CHAIN AND RETROGRADES TO NEAR SHEMYA FRIDAY WHILE
ANOTHER LOW WORKS OUT OF THE NORTH PACIFIC. THIS LOW WILL MOVE TO THE
NORTHEAST TOWARD KODIAK FROM SOUTH OF ADAK FROM FRIDAY TO SATURDAY.
THE PROGRESSION OF THIS LOW WILL PROVIDE SOME WARMING TO THE BRISTOL
BAY AREA AND EASTERN ALEUTIAN CHAIN AND INLAND SATURDAY AND SUNDAY.
HIGH PRESSURE WILL BE PUSHED OFF THE MAINLAND BY THIS LOW AS WELL.
WILL CONTINUE TO SEE STRONG WINDS ALONG THE BERING AND ALEUTIANS
THROUGH FRIDAY AS THE LOW WORKS JUST SOUTH OF THE CHAIN. GRADIENT
WEAKENS OVER THE CENTRAL AND WESTERN ALEUTIAN AS HIGH PRESSURE WORKS
SOUTH OF THE WESTERN ALEUTIANS AS WELL SATURDAY. THIS IS IN RESPONSE
TO A STRONGER SURFACE LOW SOUTH OF KAMCHATKA.

THE LOW IN THE WESTERN GULF TO REMAIN THERE OVER THE WEEKEND OR MOVE
SLIGHTLY INTO SOUTH CENTRAL. THIS WILL BRING PRECIP INLAND AND KEEP
COLD AIR MOVING INTO WESTERN ALASKA AND THE EASTERN BERING. ANOTHER
LOW WORKS TO THE WESTERN ALEUTIAN CHAIN IN THE MEANTIME.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE
MARINE...STORM 175 176
         HEAVY FREEZING SPRAY 130 160 165 179
         GALE 170 172 179
FIRE WEATHER...NONE

JN JAN 06