Heavy Freezing Spray Warning 182, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
200 PM AKST WED NOV 14 2012

.MODEL DISCUSSION...
GUIDANCE IN GOOD AGREEMENT TODAY...WITH THE NAM FINALLY COMING INTO
LINE WITH THE GLOBAL MODELS ON ITS 18Z RUN. AFTERNOON FORECAST
PACKAGE USES THE NAM MAINLY OVER LAND AND IN THE EARLY PERIODS WITH
THE GFS USED FOR MOST OF THE FORECAST.

.ANALYSIS AND UPPER LEVELS...
THERE IS AN UPPER LEVEL LOW OVER THE EASTERN BERING SEA MOVING
TOWARDS THE SOUTHEAST. A DEFORMATION ZONE ASSOCIATED WITH THIS LOW
IS OVER SOUTHWEST ALASKA AND MOVING SLOWLY EASTWARD. A WEAKER UPPER
LEVEL LOW OVER THE NORTHERN GULF OF ALASKA HAS ALMOST STALLED ALONG
THE SOUTH CENTRAL COAST AND IS SPINNING MOISTURE INTO SOUTH CENTRAL
ALASKA. A TROUGH OVER NORTHERN ALASKA IS MOVING SLOWLY SOUTH.

.SHORT TERM FORECAST...
FOR SOUTH CENTRAL ALASKA...THE GULF LOW WILL REMAIN STATIONARY AND
WEAKEN THROUGH TONIGHT THEN DISSIPATE BY THURSDAY AFTERNOON. THE
NORTHERN ALASKA TROUGH WILL CONTINUE TO MOVE SOUTH AND FORM A CLOSED
LOW OVER SOUTHWEST ALASKA THURSDAY MORNING. THIS WILL KEEP ENOUGH
DYNAMICS AND MOISTURE AROUND FOR CONTINUED CHANCES OF PRECIPITATION
INTO THURSDAY AFTERNOON...ENDING THURSDAY EVENING AS THE LOW DROPS
INTO THE GULF OF ALASKA. DRYER AND COLDER AIR WILL MOVE INTO THE
AREA THURSDAY NIGHT AND FRIDAY. ON SATURDAY AN UPPER LEVEL LOW WILL
ESSENTIALLY DEVELOP OVER SOUTH CENTRAL ALASKA BUT WILL LACK MOISTURE
AND DYNAMICS FOR ANY SHOT AT PRECIPITATION...EXCEPT ALONG THE GULF
COAST.

FOR SOUTHWEST ALASKA...THE EASTERN BERING LOW WILL QUICKLY PUSH INTO
THE GULF OF ALASKA TONIGHT. THE ASSOCIATED DEFORMATION BAND WILL
ALSO MOVE SOUTH AND DISSIPATE THURSDAY MORNING. SOME MOISTURE AND
DYNAMICS ASSOCIATED WITH THE NORTHERN ALASKA TROUGH AS IT DEVELOPS
THE CLOSED LOW WILL KEEP CHANCES OF PRECIPITATION THROUGH THURSDAY
BUT THEN DRY OUT THURSDAY NIGHT AS IT MOVES SOUTH. COLD DRY AIR WILL
MOVE INTO THE AREA THURSDAY NIGHT THROUGH SATURDAY.

FOR THE ALEUTIANS AND BERING SEA...A WEAK RIDGE WILL BUILD OVER THE
CENTRAL BERING SEA BEHIND THE EXITING EASTERN BERING LOW TONIGHT
INTO THURSDAY. A LOW WEST OF THE ALEUTIANS WILL SEND A WEATHER FRONT
ACROSS THE WESTERN ALEUTIANS ON THURSDAY...THE CENTRAL ALEUTIANS
THURSDAY NIGHT AND TO THE EASTERN ALEUTIANS BY FRIDAY AFTERNOON. ON
SATURDAY THIS FRONT WILL JUST REACH THE ALASKA PENINSULA THEN BREAK
APART.

.LONG TERM FORECAST...
THE OVER-ALL PATTERN FOR THE EXTENDED WILL CONSIST OF AN UPPER LEVEL
LOW OVER THE GULF OF ALASKA AND/OR SOUTH CENTRAL ALASKA WITH HIGH
PRESSURE OVER THE BERING SEA.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...STORM WARNING 185.
       GALE WARNING 127 150 155 160 165 170 171 172 175 176 179 180.
FIRE WEATHER...NONE.

LUDWIG NOV 12