Storm Warning 205, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
500 AM AKDT THU NOV 3 2011

.ANALYSIS AND UPPER LEVELS...

MAIN SYNOPTIC WEATHER FEATURES ARE HIGH PRESSURE OVER SOUTHCENTRAL
ALASKA AND THE GULF OF ALASKA...AS WELL AS A 974 MB LOW IN THE
CENTRAL BERING THAT IS MOVING EAST TOWARDS THE KUSKOKWIM DELTA COAST
WITH EXPECTED ARRIVAL LATE THIS AFTERNOON OR EARLY THIS EVENING. A
SECONDARY LOW DEVELOPS IN THE NORTHWEST GULF IN THE VICINITY OF THE
BARREN ISLANDS THIS EVENING AND THEN MOVES EAST INTO THE NORTHEASTERN
GULF BY LATE FRIDAY AFTERNOON. A NEW LOW CURRENTLY OVER THE KAMCHATKA
PENINSULA MOVES TO 200 MILES NORTH OF SHEMYA BY FRIDAY NIGHT...WITH
TRIPLE POINT LOW DEVELOPMENT ABOUT 150 MILES WEST OF THE PRIBILOFS
LATE FRIDAY AGAIN MOVING EAST INTO THE KUSKOKWIM DELTA COAST BY
SATURDAY WITH AGAIN SECONDARY LOW DEVELOPMENT ALONG THE GULF COAST.

.MODEL DISCUSSION...

MODELS ARE IN GOOD AGREEMENT IN THE SHORT TERM WITH NO SIGNIFICANT
DIFFERENCES. IN THE EXTENDED TIME FRAME...MODELS ARE IN DECENT
AGREEMENT ON THE TRACK OF LOW PRESSURE MOVING NORTHEAST ACROSS THE
WESTERN AND CENTRAL BERING EARLY NEXT WEEK. THE GFS MAKES THIS SYSTEM
VERY STRONG AS IT MOVES INTO THE NORTHERN BERING AT 938 MB...WHILE
THE EUROPEAN IS FARTHER WEST AND HAS A CENTRAL PRESSURE IN THE LOW TO
MID 950S. ITS STILL A LONG WAYS OUT BUT THE POTENTIAL IS THERE FOR A
SIGNIFICANT STORM IN THE CENTRAL BERING SEA IN THE MONDAY THROUGH
WEDNESDAY TIME FRAME.

.SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA...

THE HIGH WIND WARNING FOR TURNAGAIN ARM AND HIGHER ELEVATIONS...AS
WELL AS THE WINTER WEATHER ADVISORY FOR SNOW IN THE SUSITNA VALLEY
APPEAR TO BE ON TRACK WITH NO SIGNIFICANT CHANGES IN THINKING THUS
FAR.

OTHERWISE...HIGH PRESSURE OVER THE REGION THIS MORNING WILL GIVE WAY
TO INCREASING SOUTHWESTERLY FLOW ALOFT AND CLOUDS THIS MORNING...WITH
SNOW OVERSPREADING THE REGION BY THIS EVENING MOST LOCATIONS...WITH
RAIN POSSIBLY MIXING IN TOWARDS KACHEMAK BAY. DOWNSLOPE SOUTHEASTERLY
FLOW WILL LIKELY KEEP THE ANCHORAGE BOWL PRECIPITATION FREE UNTIL
SECONDARY LOW DEVELOPMENT OCCURS AND MOVES TO A LOCATION NEAR OR
SOUTH OF PRINCE WILLIAM SOUND BEGINNING AROUND EARLY FRIDAY
AFTERNOON. CLEARING TAKES PLACE FRIDAY NIGHT INTO SATURDAY BEFORE THE
NEXT SYSTEM AFFECTS THE REGION SATURDAY NIGHT THROUGH SUNDAY NIGHT.

SOUTHWEST ALASKA...

NO MAJOR CHANGES TO THE CURRENT FORECAST THINKING. BLIZZARD
CONDITIONS ARE OCCURRING ALONG THE KUSKOKWIM DELTA COAST...AND
ADVISORY-LEVEL CONDITIONS ARE...OR WILL BE OCCURRING BY LATE THIS
AFTERNOON...IN THE REMAINING AREAS. EXPECT CONDITIONS TO GRADUALLY
IMPROVE FROM WEST TO EAST FRIDAY OVER THE REGION BEFORE THE NEXT
SYSTEM AFFECTS THE AREA  SATURDAY INTO SUNDAY FROM THE WEST WITH A
NEAR REPEAT OF THE CURRENT WEATHER SYSTEM.

BERING SEA/ALEUTIANS...

LOW PRESSURE CENTER OVER THE CENTRAL BERING MOVES INLAND TONIGHT.
MODELS STILL SUGGEST POSSIBLE STORM FORCE GUSTS ON THE BACK SIDE OF
THE LOW AS IT MOVES EAST. WILL CONTINUE TO MONITOR FOR THE POSSIBLE
RE-ISSUANCE OF HIGH WIND WATCHES AND/OR WARNINGS LATER TODAY AS THIS
SYSTEM MOVES INLAND TONIGHT. THE NEXT GALE FORCE LOW PRESSURE SYSTEM
MOVES ACROSS THE REGION FROM WEST TO EAST TONIGHT THROUGH FRIDAY
NIGHT WITH SMALL CRAFT AND GALE FORCE WINDS. SECONDARY LOW
DEVELOPMENT FRIDAY NIGHT IN THE CENTRAL BERING COULD INVOLVE SHORT
TERM DEEPENING OF THE LOW AS IT MOVES TOWARDS THE SOUTHWEST COASTLINE
AND RESULT IN A BRIEF PERIOD OF STORM FORCE WINDS ACROSS SOME PART OF
THE EASTERN BERING SATURDAY AFTERNOON INTO EARLY EVENING.

.LONG TERM FORECAST...

AS MENTIONED...WILL BE WATCHING FOR THE POTENTIAL FOR A POWERFUL LOW
TO DEVELOP SOUTHWEST OF THE WESTERN ALEUTIANS AND TRACK TO THE
NORTHERN BERING SEA MONDAY THROUGH WEDNESDAY. A LOT WILL DEPEND ON
THE TRACK AND STRENGTH OF THE LOW...SO WILL CONTINUE TO MONITOR MODEL
TRENDS. CONTINUED SOUTHWEST FLOW WITH SEVERAL EMBEDDED DISTURBANCES
MOVING OVER SOUTHCENTRAL ALASKA WOULD SUGGEST THE POTENTIAL FOR
PERIODS OF SNOW THE LATTER HALF OF THE WEEKEND INTO EARLY NEXT WEEK.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...HIGH WIND WARNING...101 181.
         BLIZZARD WARNING...155.
MARINE...GALES...120 125 130 132 138 150 155 160 171 175 179 180
         STORMS...165 170 172 185
FIRE WEATHER...NONE.

29 NOV 11