Gale Warning 951, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
520 AM AKST MON NOV 15 2010

.ANALYSIS AND UPPER LEVELS...
ACROSS THE MAINLAND...THE LONG WAVE TROUGH IS SHIFTING EAST...AS A
COLD UPPER LOW OVER THE NORTHERN AK DROPS SOUTHEAST. A SHORTWAVE
TROUGH HAS EJECTED OUT OF THE KUSKOKWIM VALLEY AND IS PASSING THROUGH
THE MAT-SU VALLEY/ANCHORAGE BOWL THIS MORNING. OUT WEST...AN
UPPER-RIDGE IS BUILDING ACROSS THE BERING...AMPLIFIED BY A 150 KT
JET MAX. AT THE SURFACE...A TROUGH OF LOW PRESSURE HAS DEVELOPED JUST
EAST OF SEWARD AND IS DRIFTING SOUTHEAST. ALSO AN AREA OF HIGH
PRESSURE NEAR ADAK IS BUILDING EAST SUPPORTED BY THE RIDGING ALOFT.

.MODEL DISCUSSION...
MODELS CAPTURE THE SYNOPTIC PICTURE AND FEATURES SATISFACTORILY. WITH
WIDESPREAD COLD-ADVECTION FILTERING DOWN THE MAINLAND AND INTO THE
GULF OF AK...THE STRONGEST ASSOCIATED WINDS ARE BEST CAPTURED BY THE
NAM...BUT ALL MODELS SEEM REASONABLE.

.SHORT TERM FORECAST...
SOUTHCENTRAL...
SNOW SHOWERS TO END FROM NORTHWEST TO SOUTHEAST TODAY AS THE
SHORTWAVE TROUGH DROPS SOUTHEAST INTO THE GULF OF AK AND THE COLD/DRY
AIRMASS SCOURS OUT LOW-LVL MOISTURE. THIS WILL RESULT IN DECREASED
CLOUDINESS AND MUCH MORE SUNSHINE.  HOWEVER...BRISK NORTH WINDS WILL
DEVELOP LATER THIS AFTERNOON AND THIS EVENING. BY TUESDAY...THE
STRONGEST CORE OF WINDS LOOK TO MOVE THROUGH...WITH THE STRONGEST
WINDS ALONG THE NORTH GULF COAST. A HIGH WIND WATCH FOR THE COPPER
RIVER DELTA HAS BEEN ISSUED WITH THE MORNING PACKAGE. DROPPING
TEMPERATURES ACROSS ALL OF SOUTHCENTRAL COUPLED WITH THE WINDS WILL
PRODUCE WIND CHILLS NEAR ZERO DURING THE AFTERNOONS TO 10 TO 15 BELOW
ZERO AT NIGHT THROUGH MID-WEEK. ACROSS MARINE AREAS GALE FORCE WINDS
FILTERING THROUGH THE NORTHERN GULF WILL INCREASE TO STORM
FORCE...ESPECIALLY OUT OF FAVORED BAYS AND PASSES SUCH AS KAMISHAK
BAY. THE COLDER AIR AND WINDS ALSO SHOULD SUPPORT AREAS OF HEAVY
FREEZING SPRAY. THE COLD UPPER-LOW WILL SLIP SOUTH THROUGH THE GULF
OF AK AND INTO THE NORTH PACIFIC ON WEDNESDAY. THE PRESSURE GRADIENT
THEN LOOKS TO THEN WEAKEN ALONG WITH THE WINDS.

SOUTHWEST...
COLD DRY AIR WILL ALSO SPILL DOWN THROUGH THE SW MAINLAND THE NEXT
COUPLE OF DAYS. WIND CHILLS RANGING FROM 10 TO 25 BELOW ZERO CAN BE
EXPECTED ESPECIALLY THROUGH THE KUSKOKWIM VALLEY. THE AREA OF HIGH
PRESSURE BUILDING ACROSS THE BERING WILL OTHERWISE PROVIDE FAIR
WEATHER.

BERING SEA/ALEUTIANS...
A FRONT WILL ADVANCE TOWARDS THE WESTERN BERING/ALEUTIANS BUT STALL
OUT ON WEDNESDAY AS THE STRONG HIGH PRESSURE SUPPORTED BY THE
BLOCKING RIDGE HOLD FAST OVER THE CENTRAL BERING. PERIODS OF RAIN
LOOK TO CLIP THE FAR WESTERN ALEUTIANS. GALE-FORCE WINDS TO ACCOMPANY
THE PRECIPITATION AS THE PRESSURE GRADIENT GETS SQUEEZED BETWEEN THE
AFOREMENTIONED HIGH PRESSURE AND THE STALLING FRONT. .OTHERWISE THE
REMAINDER OF THE ALEUTIAN CHAIN AND BERING LOOK TO REMAIN RELATIVELY
DRY INTO MID-WEEK.

.LONG TERM FORECAST...
THE BLOCKING UPPER RIDGE IN THE BERING SLOWLY MOVE EAST TO THE
MAINLAND LATE IN THE WEEK. THIS LOOKS TO HELP BREAK THE COLD-SNAP
OVER THE MAINLAND. RESULTING ONSHORE FLOW HOWEVER BRINGS INCREASED
MOISTURE AND CHANCES OF PRECIPITATION.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...HIGH WIND WATCH 135
MARINE...STORM...130
         GALE...351 352 411 120 121 126 127 128 129 132 140 141 150
                160 172 175 176 185
         HEAVY FREEZING SPRAY...121 126 127 128 129 130 138 140 141
                                180
FIRE WEATHER...NONE

JAM NOV 10