Gale Warning 315, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
520 PM AKDT MON MAR 25 2013

.ANALYSIS AND UPPER LEVELS...
WIDESPREAD SNOW IS ONGOING THIS AFTERNOON FROM WESTERN PRINCE WILLIAM
SOUND AND THE ANCHORAGE BOWL INTO PORTIONS OF THE MAT-SU VALLEY AS AN
UPPER LOW OVER THE GULF OF ALASKA HAS MERGED WITH ANOTHER STRONG
UPPER LOW DROPPING SOUTHWARD OVER THE WESTERN MAINLAND...RESULTING IN
A DEEP NEGATIVELY TILTED UPPER LEVEL TROUGH OVER SOUTHCENTRAL ALASKA.
AT THE SURFACE...A WEAKENING LOW OVER WESTERN PRINCE WILLIAM SOUND
HAS HELPED TO SPREAD MOISTURE OVER SOUTHCENTRAL AK AS A VERY COLD AIR
MASS ASSOCIATED WITH THE MAINLAND UPPER LOW ADVECTS INTO THE COOK
INLET REGION FROM THE NORTHWEST. THESE FACTORS COUPLED WITH THE
AFOREMENTIONED UPPER LEVEL SUPPORT WILL SERVE TO CONTINUE AREAS OF
HEAVY SNOW ACROSS SOUTHCENTRAL AK INTO THE EVENING HOURS.
ADDITIONALLY...GUSTY GAP WINDS CONTINUE NEAR SEWARD AND WHITTIER WITH
THE LOW MOVING INTO PWS...LEADING TO BLIZZARD CONDITIONS NEAR
WHITTIER.

.MODEL DISCUSSION...
MODELS REMAIN IN GOOD OVERALL SYNOPTIC AGREEMENT THROUGH THE SHORT
TERM. THE UPPER TROUGH CURRENTLY OVER SOUTHCENTRAL AK WILL LIFT TO
THE NORTH AND EAST ON TUESDAY AS THE SURFACE LOW OVER PRINCE WILLIAM
SOUND WEAKENS AND THEN DISSIPATES...AT LEAST TEMPORARILY ALLOWING
PRECIPITATION TO COME TO AN END. A WEAK LOW TRAVERSING THE ALEUTIAN
CHAIN WILL MOVE INTO THE NORTH PACIFIC AND WEAKEN ON TUESDAY BEFORE
ANOTHER STRONGER NORTH PACIFIC LOW APPROACHES FROM THE WEST TOWARDS
THE MIDDLE OF THE WEEK.

.SHORT TERM FORECAST...
SOUTHCENTRAL ALASKA...
SNOW WILL BEGIN TO TAPER OFF ACROSS THE AREA LATE THIS EVENING AS THE
UPPER TROUGH BEGINS TO LIFT OFF TO THE NORTH AND EAST WHILE THE
SURFACE LOW OVER PRINCE WILLIAM SOUND CONTINUES TO WEAKEN.
ACCUMULATIONS WILL SUBSEQUENTLY BE LIGHTER TONIGHT...WITH AN
ADDITIONAL 1-3 INCHES POSSIBLE BY TUESDAY MORNING. A FEW SNOW SHOWERS
MAY LINGER INTO TUESDAY MORNING ACROSS THE ANCHORAGE BOWL AND MAT-SU
VALLEY. SOUTHCENTRAL AK WILL SEE A BREAK IN PRECIPITATION TUESDAY
INTO WEDNESDAY AS TRANSITORY RIDGING MOVES OVERHEAD IN THE WAKE OF
THE DEPARTING UPPER TROUGH. THE NEXT CHANCE FOR PRECIPITATION WILL
THEN ARRIVE WEDNESDAY NIGHT INTO THURSDAY AS A FRONT MOVES INTO THE
GULF AHEAD OF THE NEXT SYSTEM MOVING THROUGH THE BERING.

SOUTHWEST ALASKA...
COLD TEMPERATURES WILL CONTINUE THROUGH TUESDAY ACROSS THE NORTHWEST
MAINLAND WITH GUSTY NORTHWEST WINDS CONTINUING TO SUPPORT WINDCHILL
VALUES APPROACHING 35 BELOW ZERO TONIGHT BEFORE WINDS SUBSIDE AS THE
UPPER LOW MOVES AWAY FROM THE AREA ON TUESDAY.

ALEUTIANS/BERING SEA...
A SERIES OF NORTH PACIFIC LOWS TRAVERSING THE ALEUTIANS FROM WEST TO
EAST WILL BRING A MIX OF RAIN AND SNOW TO THE CHAIN THROUGH THE
MIDDLE OF THE WEEK. THE FIRST SYSTEM WILL MOVE AWAY FROM THE AREA AND
WEAKEN TONIGHT...BUT WILL BE FOLLOWED BY ANOTHER LOW AND ASSOCIATED
FRONT REACHING THE WESTERN ALEUTIANS EARLY TUESDAY. GUSTY WINDS AND
SNOW WILL ACCOMPANY THE FRONT AS IT ARRIVES OVER THE PRIBILOFS ON
TUESDAY...THEREFORE BLIZZARD CONDITIONS WILL BE POSSIBLE TUESDAY
EVENING INTO WEDNESDAY AFTERNOON.

.LONG TERM FORECAST...
THURSDAY AND BEYOND...A LARGE LONGWAVE TROUGH WILL BE TRACKING
ACROSS THE BERING SEA AND ALEUTIANS...WITH PRECIPITATION SPREADING
INTO SOUTHERN ALASKA THURSDAY INTO FRIDAY. THIS SYSTEM WILL DRAW
WARMER AIR BACK INTO THE AREA...WITH COASTAL LOCATIONS LIKELY MIXING
TO RAIN AS THIS SYSTEM TRACKS EAST. THEREAFTER...GLOBAL ENSEMBLE
GUIDANCE CONTINUES TO HINT AT A BREAKDOWN OF THE ARCTIC
BLOCKING...WITH MUCH UNCERTAINTY DEVELOPING WITH THIS PATTERN REGIME
CHANGE. IT DOES SEEM...HOWEVER...THAT TEMPERATURES WILL LIKELY
REMAIN AT OR POSSIBLY SLIGHTLY ABOVE NORMAL HEADING INTO NEXT WEEK.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...WINTER STORM WARNING 101
         BLIZZARD WARNING 125
         BLIZZARD WATCH 195
         WINTER WEATHER ADVISORY 111 145
MARINE...STORM WARNING 130
         GALE WARNING 120 129 138 170 176 179 185
         HEAVY FREEZING SPRAY 120 121 127 129 130 132 136 137 138
                              140 141 165 179
FIRE WEATHER...NONE

CB MAR 13

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ANCHORAGE AK
1046 PM AKDT MON MAR 25 2013

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0900 PM     SNOW             2 NW GLEN ALPS          61.12N 149.72W
03/25/2013  M16.0 INCH                          AK   TRAINED SPOTTER

            SNOW TOTAL SINCE 6PM SUNDAY NIGHT IS 16 INCHES WITH 3.5
            INCHES IN THE LAST 3 HOURS.

0900 PM     SNOW             2 SE EAGLE RIVER        61.30N 149.53W
03/25/2013  M10.0 INCH                          AK   NWS EMPLOYEE

            STORM TOTAL OF 10 INCHES WITH 6.5 INCHES SINCE 8 AM
            TODAY.

0935 PM     SNOW             2 ENE RABBIT CREEK      61.10N 149.77W
03/25/2013  M19.0 INCH                          AK   NWS EMPLOYEE

            4 INCHES OF NEW SNOW SINCE 2 PM WITH STORM TOTAL OF 19
            INCHES.

0635 PM     SNOW             1 NNE POTTER MARSH      61.07N 149.77W
03/25/2013  M14.8 INCH                          AK   TRAINED SPOTTER

            STORM TOTAL.

1000 PM     SNOW             6 SW ANCHORAGE          61.15N 150.00W
03/25/2013  M13.1 INCH                          AK   OFFICIAL NWS OBS

            STORM TOTAL OF 13.1 INCHES WITH 7.3 TOTAL FOR THE DAY.

&&

DSTRICKL

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ANCHORAGE AK
128 AM AKDT TUE MAR 26 2013

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0308 PM     SNOW             1 ENE POTTER MARSH      61.06N 149.76W
03/25/2013  M17.0 INCH                          AK   TRAINED SPOTTER

            STORM TOTAL OF 17 INCHES, 12 INCHES FROM 5 AM UNTIL 3 PM.

&&

DSTRICKL