Gale Warning 779, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 AM AKST WED NOV 4 2009

.ANALYSIS AND UPPER LEVELS...

A NEGATIVELY TILTED UPPER LEVEL TROUGH EXTENDS FROM SIBERIA...ACROSS
THE BERING AND AKPEN...ACROSS THE GULF AND THEN INTO THE EASTERN
PACIFIC THIS MORNING. UPPER LEVEL LOW CENTERS EMBEDDED IN THIS TROUGH
ARE OVER THE ENTIRE BERING AND SOUTH OF THE GULF OF ALASKA. A RIDGE
IS CENTERED ALONG THE COAST OF SOUTHEAST AK. AT THE SURFACE...AN AREA
OF LOW PRESSURE EXTENDS FROM THE BERING TO THE WASHINGTON OREGON
COAST. LOW CENTERS WITHIN THIS AREA ARE LOCATED OVER THE AKPEN AND
EASTERN BERING...AND WELL SOUTH OF THE GULF. REMNANTS OF A FRONT ARE
OVER SOUTHWEST AK AND THE AK AND ALEUTIAN RANGES...WHILE A SECOND
FRONT IS MAKING SLOW PROGRESS UP THE AKPEN.

.MODEL DISCUSSION...

MODELS ARE IN FAIR AGREEMENT WITH A COMPLEX PATTERN. ALL AGREE THAT
THE AKPEN LOW WILL MOVE INTO THE GULF THIS AFTERNOON...MERGING WITH
THE LOW THAT STARTS THE DAY SOUTH OF THE GULF. THE COMBINED LOW WILL
DEEPEN TO AROUND 948 MB TONIGHT AND IN THE EC PREFERRED SOLUTION SPIN
AROUND IN THE NORTHEASTERN GULF UNTIL DISSIPATING SAT NIGHT.
MEANWHILE RIDGING SPREADS ACROSS THE BERING AND ANOTHER ALEUTIAN LOW
RACES TO THE SOUTHEASTERN GULF BY SUN NIGHT. THE FORECAST USES THE
NAM AND GFS IN THE EARLY PERIODS FOR DETAIL...AND THEN BLENDS TOWARD
THE 00Z EC AND SOME HPC GUIDANCE IN THE MID AND LONG RANGE.

.SHORT TERM FORECAST...

IN THE WEST...THE BERING AND ALEUTIANS WILL BE DOMINATED BY GALE AND
STORM FORCE WEST TO NORTHWEST FLOW THROUGH THURSDAY NIGHT IN THE
WESTERN HALF AND THROUGH SAT IN THE EASTERN HALF. THESE WINDS WILL BE
ACCOMPANIED BY SNOW SHOWERS. DRYING BENEATH A RIDGE WILL AFFECT THE
WESTERN PORTION FRI AND SAT AND THE EASTERN AREA SUN.  A WEATHER
FRONT FROM AN EASTERN RUSSIA LOW WILL MOVE ACROSS THE BERING SUN AND
SUN NIGHT...PRECEDED BY ANOTHER ROUND OF RAIN AND STRONG WINDS AND
FOLLOWED BY SNOW SHOWERS.

FOR SOUTHWEST AK...STRONG WIND THROUGH CHANNELED TERRAIN ALONG WITH
RAIN WILL AFFECT AREAS NEAR THE ALEUTIAN RANGE TODAY WITH SNOW AND
WIND ACROSS THE REST OF THE AREA. SOME RAIN/SNOW SHADOWING CAN BE
EXPECTED NEAR THE ALASKA RANGE. WARMER AIR WILL WRAP INTO THE AREA
TONIGHT AS THE LOWS CONSOLIDATE IN THE GULF. DRYER CONDITIONS WILL
MOVE INTO THE AREA THU. COLDER TEMPERATURES RETURN FRI AND LAST
THROUGH THE WEEKEND WITH SOME SNOW SHOWER ACTIVITY ON NORTHWEST FLOW.

SOUTH AND EAST OF THE AK RANGE...SOUTHEAST FLOW WILL BRING ABUNDANT
PRECIPITATION ONSHORE TODAY WITH RAIN ALONG THE COAST AND SIGNIFICANT
SNOWFALL TO EAST FACING SLOPES OF THE AK RANGE. THE LATTER WILL CUT
OFF WHEN THE LOWS CONSOLIDATE IN THE GULF THU AND FLOW BECOMES
NORTHEAST. FROM THAT POINT UNTIL THE GULF LOW DISSIPATES ON
SUN...PRECIPITATION WILL BE MAINLY LIMITED TO COASTAL SECTIONS AND
MOUNTAINS...ALTHOUGH WARM AIR MOVING INLAND WILL CAUSE MOST OF THIS
TO BE RAIN.

.LONG TERM FORECAST...

SNOW SHOWERS CAN BE EXPECTED EARLY NEXT WEEK IN THE FAR WEST...WHILE
WIND AND RAIN WILL AFFECT THE EASTERN BERING. SOUTHWEST AK WILL BE
DRY UNTIL THE FRONT ARRIVES WITH WIND...AND SNOW CHANGING TO RAIN MON
AND TUE. SOUTHEAST OF THE AK RANGE WILL BE DRY AT THE BEGINNING OF
THE WEEK.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE
MARINE...GALES 129 132 138 140 141 160 165 171 175 176 179 185
         STORMS 120 125 130 150 155 170 172
FIRE WEATHER...NONE

DS NOV 09