Heavy Freezing Spray Warning 197, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
500 PM AKST SAT NOV 24 2012

.ANALYSIS AND UPPER LEVELS...
THE BLOCKED UPPER LEVEL PATTERN CONTINUES THIS AFTERNOON WITH A
CLOSED HIGH CENTERED OVER THE CHUKCHI SEA PROMOTING COLD AND DRY
CONDITIONS OVER MOST OF MAINLAND ALASKA. SEVERAL LOW PRESSURE CENTERS
ARE APPARENT ON SATELLITE IMAGERY...WITH AN ELONGATED UPPER LOW
SUPPORTING SNOW SHOWERS FROM THE NORTHERN AKPEN TO THE EASTERN
ALEUTIANS AND ANOTHER NORTH PACIFIC LOW LOCATED WELL TO ITS SOUTH
ALONG 50N. MEANWHILE...THE STRONG LOW THAT HAD BEEN OVER THE EASTERN
GULF OF ALASKA FOR THE PAST FEW DAYS CONTINUES TO WEAKEN AS IT MOVES
INLAND OVER THE PANHANDLE.

.MODEL DISCUSSION...
MODELS ARE IN REASONABLE AGREEMENT IN HANDLING THE MAIN FEATURES
THROUGH THE SHORT TERM...THEN BEGIN TO DIVERGE EARLY NEXT WEEK AS THE
BLOCKING PATTERN STARTS TO BREAK DOWN. THE NORTH PACIFIC LOW WILL
MOVE NORTH AND MERGE WITH THE UPPER LOW CURRENTLY OVER THE AKPEN
SOUTH OF KODIAK ISLAND ON SUNDAY. THIS SYSTEM WILL THEN BE PUSHED
SOUTH INTO THE NORTHERN PACIFIC EARLY NEXT WEEK AS THE CHUKCHI SEA
HIGH SLIDES SOUTHWARD.

.SHORT TERM FORECAST...
SOUTHCENTRAL ALASKA...
SNOW ASSOCIATED WITH THE AKPEN UPPER LOW WILL CONTINUE THROUGH
TONIGHT OVER KODIAK ISLAND AND THEN MIX WITH RAIN ON SUNDAY AS THE
NORTH PACIFIC LOW APPROACHES...WITH LITTLE OR NO ACCUMULATION
EXPECTED. A FEW SNOW SHOWERS COULD MAKE IT AS FAR NORTH AS THE
SOUTHERN KENAI PENINSULA THROUGH THIS EVENING. ELSEWHERE ACROSS
SOUTHCENTRAL...MORE OF THE SAME AS COLD AND DRY CONDITIONS WILL
PERSIST INTO NEXT WEEK. GUSTY NORTH WINDS WILL REMAIN POSSIBLE
THROUGH GAPS IN THE TERRAIN ALONG THE NORTHERN GULF COAST WITH COLD
AIR AND HIGH PRESSURE ENTRENCHED OVER THE INTERIOR AND LOW PRESSURE
OVER THE GULF.

SOUTHWEST ALASKA...
LIGHT SNOW WILL CONTINUE INTO THE EVENING HOURS ALONG THE AKPEN AND
COASTAL PORTIONS OF BRISTOL BAY WITH THE LOW REMAINING OVERHEAD.
OTHERWISE...PERSISTENT OFFSHORE FLOW WILL CONTINUE TO FAVOR COLD AND
DRY CONDITIONS ACROSS THE SOUTHWEST MAINLAND INTO THE EARLY PART OF
NEXT WEEK.

ALEUTIANS/BERING SEA...
A FRONT WILL BRING RAIN AND STRONG SOUTHERLY WINDS TO THE WESTERN AND
CENTRAL ALEUTIANS THROUGH TONIGHT AND THEN TO THE EASTERN PART OF THE
CHAIN ON SUNDAY AS IT TRAVERSES THE BERING. A RAIN/SNOW MIX WILL
CONTINUE INTO MONDAY AS THE FRONT STALLS OVER THE EASTERN BERING AND
A NEW SURFACE LOW FORMS ALONG IT NEAR THE TIP OF THE AKPEN.

.LONG TERM FORECAST...
A SIMILAR PATTERN LOOKS TO CONTINUE INTO THE EXTENDED TERM WITH
MODELS GENERALLY HINTING AT RIDGING OVER THE BERING AND A TROUGH OVER
THE NORTHEAST PACIFIC. THIS WOULD SUGGEST A CONTINUATION OF COLD AND
DRY NORTHERLY FLOW OVER THE SOUTHERN MAINLAND.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE
MARINE...GALE WARNING 127 128 175 176
FIRE WEATHER...NONE

CB NOV 12