Area Forecast Discussion
Issued by NWS Anchorage, AK

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FXAK68 PAFC 260038
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
338 PM AKST SUN JAN 25 2015

.ANALYSIS AND UPPER LEVELS...

THE MAIN UPPER LEVEL TROUGH EXTENDS OUT OF AN UPPER LOW OVER THE
ARCTIC AND EXTENDS SOUTHWARD OVER THE COPPER RIVER BASIN AND
PRINCE WILLIAM SOUND THIS AFTERNOON. THERE IS A SECONDARY TROUGH
THAT IS DIGGING ACROSS THE BERING SEA AND WESTERN ALEUTIANS WHICH
IS KEEPING THE JET STREAM SOUTH OF THE AREA AND SERVING AS THE
FOCAL POINT FOR A SURFACE LOW THAT IS SOUTH OF THE ALEUTIANS AND
HEADING EASTWARD. THE FRONT ASSOCIATED WITH THIS SURFACE LOW IS
PUSHING NORTH OF THE ALEUTIANS INTO THE BERING SEA OVERNIGHT
TONIGHT.
A WEAK SURFACE LOW DEVELOPED IN EASTERN PRINCE WILLIAM SOUND EARLY
THIS MORNING AND IS MOVING SLOWLY EASTWARD. THIS FEATURE ENHANCED
SNOW SHOWERS OVER THE VALDEZ AND CORDOVA AREAS TODAY.

&&

.MODEL DISCUSSION...
MODELS INITIALIZE VERY WELL AND ARE SHOWING GOOD CONSISTENCY FOR
THE FIRST TWO DAYS BEFORE A COMPLEX LOW MOVING TOWARD THE AREA
FROM THE SOUTH TUESDAY NIGHT IS SHOWING QUITE A DIFFERENCE BETWEEN
MODEL SOLUTIONS. AS WITH THE COMPLEX LOW FROM LAST WEEK THE MODELS
HAVE MORE OR LESS A COMMON TROUGH AXIS WHERE THEY PLACE THE LOW.
HOWEVER THE MODELS ARE STRUGGLING WITH THE WAY THE LOW SPLITS ITS
DOUBLE CENTERS AND MODEL SOLUTIONS ARE HUNDREDS OF MILES APART.
THE GFS IS SHOWING ITS TYPICAL ERROR OF CONSOLIDATING ITS ENERGY
INTO A SINGLE LOW CENTER WHICH IS NOT LIKELY TO OCCUR.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...

BITTER COLD CONTINUES TO SETTLE OVER SOUTHCENTRAL TONIGHT INTO
TUESDAY. TONIGHT`S LOWS WILL BE COLDEST OF THE SEASON OVER
ANCHORAGE...AND SHOULD EASILY BREAK THE LONG STREAK OF
CONSECUTIVE DAYS ZERO OR ABOVE FOR TED STEVENS INTERNATIONAL
AIRPORT. THE COLD WILL REMAIN IN PLACE AT LEAST THROUGH TUESDAY
NIGHT...WITH MODEST IMPROVEMENTS TOWARD MIDWEEK.

WITH SUCH A DEEP POCKET OF COLD AIR OVER THE SOUTHERN
INTERIOR...GUSTY OUTFLOW GAP WINDS CAN BE EXPECTED TO CONTINUE THE
NEXT FEW DAYS...BUT GENERALLY BELOW STRONG WIND CRITERIA WITH A
LACK OF UPPER LEVEL SUPPORT TO ENHANCE THESE WINDS.

PRECIPITATION SHOULD REMAIN CONFINED TO COLD ADVECTION SNOW SHOWERS
ALONG LOWER COOK INLET...THE NORTHERN GULF...SHELIKOF STRAIT...PRINCE
WILLIAM SOUND...AND MAINLY SOUTHERN PARTS OF KODIAK ISLAND...WITH
THE MORE SUSTAINED SHOWERS FOCUSED NEAR A CONVERGENCE BOUNDARY
ALONG THE NORTHERN GULF LATE TONIGHT THROUGH TUESDAY NIGHT.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (TODAY AND MONDAY)...
NOW THAT THE ARCTIC AIR MASS HAS SET UP OVER THE INTERIOR
SOUTHWEST TEMPERATURES WILL STRUGGLE TO RECOVER MUCH TODAY WITH
LITTLE CHANGE IN WIND OR CLOUD COVER EXPECTED. THIS WILL CHANGE
TONIGHT AS A WAVE DEVELOPS IN THE BERING...INCREASING THE OFFSHORE
WINDS THROUGHOUT THE KUSKOKWIM DELTA AND BRISTOL BAY. THIS WILL
CREATE DANGEROUSLY LOW WIND CHILLS LATE TONIGHT AND TOMORROW
MORNING...ESPECIALLY FOR THE KUSKOKWIM DELTA WHERE A WIND CHILL
ADVISORY HAS BEEN ISSUED FOR WIND CHILLS AS LOW AS 45 BELOW ZERO.
TEMPERATURES WILL THEN SLOWLY RISE ON MONDAY AS WINDS AND CLOUDS
INCREASE. THIS INCREASING CLOUD COVER WILL MOVE IN AS A RESULT AS
A SHORTWAVE MOVING IN FROM THE AKPEN. THIS WILL BRING
ACCUMULATING SNOW TO THE WESTERN BRISTOL BAY FROM LATE MONDAY INTO
TUESDAY. THIS WAVE HAS TO POTENTIAL TO BRING SIGNIFICANT
ACCUMULATIONS TO THE DILLINGHAM AREA BY TUESDAY MORNING...HOWEVER
DUE TO SOME DISAGREEMENT IN HOW FAR EAST THE SNOW WILL REACH AND
STRENGTH OF THE UPPER LEVEL WAVE...ITS TOO SOON TO SAY EXACTLY HOW
MUCH SNOW COULD FALL.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (TODAY AND MONDAY)...
THE FRONT ASSOCIATED WITH THE LOW CURRENTLY JUST SOUTH WILL
CONTINUE TO BRING RAIN AND SNOW FROM THE CENTRAL ALEUTIANS...BECOMING
SNOW AS IT SPREADS INTO THE EASTERN ALEUTIANS AND AKPEN BY THIS
LATE THIS AFTERNOON. THIS SYSTEM WILL THEN SPREAD INTO THE BERING
AND TOWARDS THE PRIBILOFS THIS EVENING...HOWEVER THE MODELS HAVE
TRENDED FURTHER SOUTH AND MUCH LIGHTER WITH THE SNOWFALL AS IT
APPROACHES THE ISLANDS BY MONDAY MORNING. IT IS FOR THIS
REASON...AND BECAUSE OF THE LACK OF CURRENT TRANSPORTABLE SNOW AND
UNSEASONABLY WARM WATERS IN THE BERING THAT THE BLIZZARD WATCH
THERE WAS CANCELLED THIS MORNING. THERE STILL WILL BE AREAS OF
BLOWING SNOW AS STRONG WINDS KICK UP WHATEVER DOES FALL...HOWEVER
AT THIS POINT IT DOES NOT APPEAR THIS WILL BE ENOUGH TO CREATE
BLIZZARD CONDITIONS.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...
RIDGING WILL BUILD IN OVER THE BERING AND EXTEND OVER MAINLAND
ALASKA BY THE END OF THE WEEK. THIS WILL KEEP THE MAJORITY OF THE
PRECIPITATION OVER THE NORTH PACIFIC AND GULF OF ALASKA.
ADDITIONALLY...THE RIDGING WILL KEEP DRY AND COLD NORTHEASTERLY
FLOW OVER THE SOUTHWEST PART OF THE STATE. THIS PATTERN WILL
CONTINUE INTO THE WEEKEND UNTIL A LOW FROM NORTHEASTERN RUSSIA
MOVES INTO MAINLAND ALASKA.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...WIND CHILL ADVISORY 155.
MARINE...GALE WARNING 130 160 165 170 175 176 177 178 179 180.
         HEAVY FRZ SPRAY 121 125 126 127 128 129 130 139 140 141
           160 165 179 180 185.
FIRE WEATHER...NONE.

&&

$$

SYNOPSIS AND MODEL DISCUSSION...EZ
SOUTHCENTRAL ALASKA...CC
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...MC
LONG TERM...DK


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