Gale Warning 344, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
601 AM AKDT SAT APR 10 2010

.ANALYSIS AND UPPER LEVELS...
A SHARP UPPER LEVEL RIDGE IS CURRENTLY CENTERED OVER KODIAK ISLAND
AND CURVES NORTHWESTWARD TOWARDS THE BEAUFORT SEA. MEANWHILE A DEEP
UPPER LEVEL LOW IS 400 MILES NORTHEAST OF SHEMYA. A 150 KT JET IS
LOCATED ALONG THE BORDER BETWEEN THIS UPPER LEVEL LOW AND
RIDGE...WHILE A NORTH-SOUTH 150 KT JET IS JUST EAST OF CORDOVA.

.AT THE SURFACE...
 A REMARKABLE SURFACE LOW 400 MILES NORTHEAST OF SHEMYA HAS ALREADY
REACHED ITS PEAK INTENSITY OF 954 MB IN THE NORTH BERING AND HAS
BECOME AN OCCLUDED CYCLONE. THE PEAK OF THE WARM SECTOR IS NOW
DISCONNECTED FROM THE LOW AND LOCATED SOUTH OF SAND POINT WITH THE
OCCLUDED FRONT STRETCHING NORTHWESTWARD TO THE LOW. THIS OCCLUDED
FRONT IS STILL SUPPORTING STRONG WINDS ALONG THE WEST MAINLAND COAST
AND ACROSS THE ALASKA PENINSULA.  HEAVY SNOW IS FALLING ALONG THE
WESTERN CAPES WHILE RAIN AND SNOW CONTINUES TO FALL ACROSS THE ALASKA
PENINSULA.

.MODEL DISCUSSION...MODELS ARE SHOWING GENERAL AGREEMENT ON THE
EVOLUTION OF THE POTENT LOW. THE GFS IS FAVORING A SLOWER PROGRESSION
OF THE FRONT OVER SOUTHCENTRAL AND WAS CHOSEN FOR THE SHORT TERM.
THE LATEST MODEL RUNS INDICATE AND OBSERVATIONS CONFIRM...THAT COOLER
AIR IS BEHIND THE OCCLUDED FRONT THAN WHAT WAS ANTICIPATED IN
PREVIOUS RUNS.  AS A RESULT...TRENDED PRECIPITATION TYPE IN ZONE 161
TOWARDS SNOW FOR TODAY.  FOR THE LONG TERM...MODELS DIVERGE
CONSIDERABLY SO THERE IS LOW CONFIDENCE...BUT THE ECMWF WAS CHOSEN.

.SHORT TERM FORECAST...
.SOUTHCENTRAL...THE BEAUTIFUL WEATHER THAT HAS BEEN OCCURRING ACROSS
THE SOUTHCENTRAL REGION WILL BE COMING TO AN END TODAY AS A FRONT
ASSOCIATED WITH THE BERING LOW MOVES INTO THE REGION THIS AFTERNOON
AND EVENING. THE FRONT WILL ESSENTIALLY STALL OVER THE SUSITNA VALLEY
AND PRINCE WILLIAM SOUND REGIONS. AS A RESULT...THERE IS A CHANCE FOR
PRECIPITATION ACROSS THE AREA FROM SATURDAY NIGHT INTO MONDAY.
ALTHOUGH THE ANCHORAGE BOWL REGION WILL BE MOSTLY DOWNSLOPED...SNOW
IS STILL EXPECTED TO OCCUR WITH THIS SYSTEM. MODELS INDICATE THAT A
SUBSTANTIAL AMOUNT OF PRECIPITATION MAY OCCUR OVER HOMER...WITH UP TO
6 INCHES OF SNOW ON THE BLUFF AND MIXED PRECIPITATION IN TOWN. MODELS
ALSO INDICATE THAT MORE THAN 6 INCHES OF SNOW MAY OCCUR NORTH OF
TALKEETNA WITH THIS EVENT.

.SOUTHWEST ALASKA...THE BLIZZARD WARNING FOR THE KUSKOKWIM DELTA
COAST HAS ALREADY VERIFIED WITH WIND GUSTS UP TO 50 KTS REPORTED
ALONG THE COAST AND VISIBILITIES AT 1/4 OR LESS REPORTED AT HOOPER
BAY AND MEKORYUK THIS EVENING. SNOW AND WINDY CONDITIONS ARE EXPECTED
TO CONTINUE TO MOVE INLAND INTO THIS MORNING WITH VISIBILITIES
REMAINING ABOVE 1/4 MILE INLAND. SNOW IS EXPECTED TO CONTINUE ACROSS
THE SOUTHWEST TODAY AS THE FRONT CONTINUES INLAND. BEHIND THE
FRONT...THE SNOWFALL WILL DIMINISH TO SCATTERED SHOWERS ALONG THE
COAST OVER NIGHT. THE NEXT LOW PRESSURE SYSTEM WILL BRING
PRECIPITATION TO THE COAST BY SUNDAY NIGHT.

.BERING SEA/ALEUTIANS/PRIBILOFS...PRECIPITATION AND WINDS CONTINUE TO
IMPACT THE ALEUTIAN ISLANDS...ALTHOUGH WINDS HAVE DECREASED ACROSS
THE EASTERN ALEUTIAN ISLANDS AFTER THE PASSING OF THE FRONT THIS
EVENING. SNOW SHOWERS WITHIN THE COLD ADVECTION REGION OF THE LOW
CONTINUE TO IMPACT THE WESTERN ALEUTIANS...WHILE MOSTLY RAIN HAS BEEN
IMPACTING THE EASTERN ALEUTIANS CLOSER TO THE WARM SECTOR OF THE LOW.
ALTHOUGH A LOW LEVEL JET LOCATED ALONG THE SOUTHWESTERN PORTION OF
THE LOW HAS BEEN BRINGING WIND GUSTS UP TO 53 KTS TO SHEMYA
OVERNIGHT...THE WINDS WILL BEGIN TO DIMINISH AS THIS JET WEAKENS AND
MOVES TO THE NORTH. A SERIES OF LOWS MOVING ACROSS THE REGION WILL
RESULT IN THE CHANCE FOR SHOWERS ACROSS THE ALEUTIANS THROUGH LATE
NEXT WEEK.

.LONG TERM...AN ACTIVE PATTERN WILL CONTINUE OVER THE NEXT WEEK AS A
RATHER POTENT UPPER LEVEL JET REMAINS WITHIN THE REGION. EXPECT
UNSETTLED WEATHER TO CONTINUE ACROSS THE STATE WITH SOME BREAKS OVER
SOUTHCENTRAL.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...BLIZZARD WARNING...155
MARINE...STORM...180
        GALE..130 132 136 137 138 140 150 155 160 165 172 175 176
                185
FIRE WEATHER...NONE.

ELN APR 10