Gale Warning 894, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
130 PM AKST FRI NOV 13 2010

.ANALYSIS AND UPPER LEVELS...AMPLIFIED PATTERN REMAINS IN PLACE
ACROSS THE NORTHWESTERN PACIFIC. A BROAD AREA OF LOW PRESSURE
PERSISTS OVER MUCH OF THE MAINLAND WITH A STRONG JET FLOWING
SOUTHWEST TO NORTHEAST TOWARD THE PANHANDLE. A SIGNIFICANT SHORT WAVE
EMBEDDED WITHIN THE SOUTHWESTERLY FLOW MOVED INLAND OVERNIGHT
BRINGING MANY AREAS AROUND SOUTHCENTRAL RAIN AND SNOW. A FEW WEAKER
SHORT WAVES CAN BE SEEN ON THE WATER VAPOR IMAGERY AROUND THE ALASKA
PENINSULA. THE COLDEST AIR IS STILL LOCKED UP NORTH OF THE KUSKOKWIM
DELTA. THIS AIR WILL START TO ADVANCE SOUTH AND EAST DURING THE
WEEKEND AS THE UPPER TROUGH AXIS SHIFTS EAST AND A LARGE UPPER RIDGE
BUILDS OVER THE BERING SEA.

.MODEL DISCUSSION...
MODELS ARE IN EXCELLENT AGREEMENT THROUGH THE SHORT TERM. ALL MODELS
INDICATING LARGE BUT GRADUAL CHANGE IN THE PATTERN LATE THIS WEEKEND
AND INTO EARLY NEXT WEEK AS THE TROUGH SHIFTS EAST AND A HIGH
AMPLITUDE RIDGE BUILDS OVER THE BERING SEA. MINOR DIFFERENCES IN THE
TIMING ON MONDAY NIGHT AS THE COLD AIR CROSSES THE ALASKA PENINSULA
AND ENTERS THE WESTERN GULF AND SOUTHCENTRAL ALASKA. AT THIS
TIME...THE GFS AND ECMWF ARE IN BETTER AGREEMENT AND HAVE BEEN
CONSISTENT SO WILL BE STICKING WITH THE GFS THROUGH EARLY NEXT WEEK.

.SHORT TERM FORECAST...
MAINLAND ALASKA...MUCH MORE STRAIGHT FORWARD FORECAST TODAY WITH
BROAD SOUTHWESTERLY FLOW ACROSS THE MAINLAND. ISOLATED TO SCATTERED
SHOWERS CONTINUE TO DEVELOP OVER THE WESTERN KENAI PENINSULA UP
THROUGH THE SUSITNA VALLEY. NUMEROUS SHOWERS PERSIST OVER THE NORTH
GULF COAST FROM THE COPPER RIVER DELTA TO THE EASTERN KENAI. THIS
ACTIVITY WILL CONTINUE THROUGH THE NEXT 24 HOURS. SUNDAY...A WEAK LOW
WILL DEVELOP NEAR MIDDLETON ISLAND AS A MORE VIGOROUS SHORT WAVE
MOVES ACROSS THE REGION. THIS SURFACE LOW WILL BEGIN TO TIGHTEN THE
PRESSURE GRADIENT ALONG THE COAST AND WILL BE REINFORCED WHEN THE
COLD AIR MOVES ACROSS THE ALASKA RANGE INTO THE WESTERN GULF MONDAY.

BY TUESDAY...THE BUILDING RIDGE OVER THE BERING SEA AND DEEPENING
TROUGH OVER THE GULF WILL STRENGTHEN THE WINDS THROUGH THE GAPS TO
GALE FORCE OVER MOST OF THE NORTHWESTERN GULF THROUGH MID WEEK. STORM
FORCE GUSTS ARE POSSIBLE THROUGH THE BARREN ISLANDS.

LIGHT SNOW AND LOW CLOUDS PERSIST OVER BRISTOL BAY AND THE KUSKOKWIM
DELTA. DRIER AND COLDER AIR ASSOCIATED WITH THE NORTHWESTERLY FLOW
EARLY NEXT WEEK WILL SLOWLY FILTER SOUTH. TEMPERATURES WILL DROP
BELOW CLIMATOLOGICAL NORMAL BY TUESDAY AND WEDNESDAY IN PLACES LIKE
BETHEL BEFORE REBOUNDING LATER IN THE WEEK.

BERING SEA/ALEUTIANS...THE COLD AIR ALOFT UNDER THE BROAD CYCLONIC
CIRCULATION IS RESULTING IN WIDESPREAD SHOWER ACTIVITY ACROSS THE
BERING SEA. HIGH PRESSURE BUILDS FROM THE WEST LATER SUNDAY AND
SPREADS OVER THE CENTRAL BERING MONDAY. WINDS WILL BE RELATIVELY
LIGHT UNDER THIS HIGH PRESSURE...ALTHOUGH CEILINGS AND VISIBILITY
WILL LIKELY BECOMING MARGINAL TO IFR AS THE WEEK WEARS ON.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE 130.
FIRE WEATHER...NONE.

AB NOV 10