Gale Warning 846, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 PM AKST MON NOV 9 2009

.ANALYSIS AND UPPER LEVELS...
UPPER LEVELS...THE UPPER SHORTWAVE OVER THE COPPER RIVER BASIN
CONTINUES TO MOVE EAST. ANOTHER UPPER SHORTWAVE OVER THE SEWARD
PENINSULA AND NORTON SOUND IS MOVING SOUTHEAST TOWARD SOUTHCENTRAL
ALASKA. A STRONG WESTERLY JET CUTS ACROSS THE KAMCHATKA PENINSULA AND
THE NORTHERN BERING BEFORE IT TURNS SOUTHEAST OVER SOUTHWEST ALASKA.
AT THE SURFACE...A MODERATE LOW OVER THE SEWARD PENINSULA EXTENDS A
COLD FRONT THROUGH THE SOUTHWEST INTERIOR. THERE IS A WEAK LOW OVER
THE NORTHERN GULF. A HIGH OVER THE CENTRAL NORTH PACIFIC IS EXTENDING
A RIDGE INTO THE CENTRAL BERING SEA. A DEVELOPING LOW NEAR THE
KAMCHATKA PENINSULA MOVING RAPIDLY EAST.

.MODEL DISCUSSION...
THE MODELS ARE IN GOOD AGREEMENT THROUGH WEDNESDAY NIGHT BEFORE
SIGNIFICANT DISAGREEMENTS DEVELOP OVER THE ALEUTIANS AND SOUTHERN
BERING SEA THURSDAY AND FRIDAY.

.SHORT TERM FORECAST...
UPPER LEVELS...THE FIRST SHORTWAVE OVER THE COPPER RIVER BASIN WILL
DISSIPATE OVER THE WRANGELL MOUNTAINS TONIGHT. THE SECOND SHORTWAVE
OVER NORTON SOUND WILL MOVE INTO THE SUSITNA VALLEY AND KENAI
PENINSULA LATE TONIGHT AND PASS THROUGH THE COPPER RIVER BASIN
TUESDAY AND INTO THE YUKON TERRITORY TUESDAY NIGHT. AN UPPER RIDGE
DEVELOPING OVER THE CENTRAL BERING TONIGHT WILL MOVE INTO WESTERN
ALASKA TUESDAY AND THROUGH SOUTHCENTRAL ALASKA TUESDAY NIGHT AND
WEDNESDAY.

SOUTHCENTRAL ALASKA AND THE GULF...SNOW OVER THE COPPER RIVER BASIN
ASSOCIATED WITH THE FIRST SHORT WAVE WILL DIMINISH LATE TONIGHT. THE
SECOND SHORTWAVE MOVING THROUGH THE AREA WILL BRING A LITTLE MORE
SNOW INTO THE SUSITNA AND MATANUSKA VALLEYS AND THE ANCHORAGE BOWL
TONIGHT AND INTO THE COPPER RIVER BASIN TUESDAY. A WEATHER FRONT
DEVELOPING OVER THE BERING SEA TUESDAY WILL MOVE INTO THE SUSITNA
VALLEY, KENAI PENINSULA AND KODIAK ISLAND WEDNESDAY. MORE SNOW WILL
MOVE INTO THE REGION MAINLY WEST OF THE TALKEETNA AND KENAI MOUNTAINS
WHILE RAIN MOVES INTO KODIAK WEDNESDAY.

SOUTHWEST ALASKA...THE WEATHER FRONT OVER THE SOUTHWEST INTERIOR WILL
WEAKEN ALONG THE ALEUTIAN RANGE TONIGHT. THE SNOW WILL CHANGE TO
SCATTERED SNOW SHOWERS BEHIND THE FRONT. A WARM FRONT OVER THE
CENTRAL BERING WILL MOVE INTO SOUTHWEST ALASKA TUESDAY BUT IT WILL BE
FOLLOWED BY AN INTENSE COLD FRONT WEDNESDAY MORNING. A MIXTURE OF
RAIN AND SNOW WITH POSSIBLE ISOLATED POCKETS FREEZING WILL MOVE INTO
THE REGION TUESDAY AND TUESDAY NIGHT, BUT WILL RAPIDLY SWITCH TO SNOW
WEDNESDAY MORNING.

BERING SEA...A 994 MB LOW OVER THE NORTHWEST BERING WILL STRENGTHEN
TO 964 MB OVER THE SEWARD PENINSULA WEDNESDAY. A COLD FRONT TRAILING
TO THE SOUTHWEST OF THE LOW WILL SWEEP EASTWARD THROUGH THE BERING
AND THE ALEUTIANS THROUGH TUESDAY NIGHT AND MOVE INTO MAINLAND ALASKA
AND THE GULF WEDNESDAY.

.LONG TERM FORECAST...
DUE TO A HUGE CONFLICT IN THE MID-RANGE MODELS ALONG THE ALEUTIANS
THURSDAY, WHICH WILL PROPAGATE TO THE REST OF THE STATE BY SATURDAY,
CONFIDENCE IS CURRENTLY VERY LOW.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE WARNING 120 129 130 132 138 155 165 170 172 175
         179 180 185.
FIRE WEATHER...NONE.

NM NOV 09