Small Craft Advisory 243, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
200 PM ADT MON MAR 17 2008

.ANALYSIS...
LARGE SURFACE LOW IN THE GULF OF ALASKA WITH ANOTHER LOW WEST OF
SHEMYA THIS AFTERNOON. A STRONG JET FEEDING THE LOW WEST OF SHEMYA
THIS AFTERNOON AND SHOULD PUSH IT RATHER QUICKLY THROUGH THE
ALEUTIANS TOMORROW. THIS LOW TO WRAP AROUND THE GULF LOW AND COMBINE
INTO A LARGE LOW THURSDAY. MEANWHILE...THE CURRENT GULF LOW TO MOVE
ONSHORE OVER THE KENAI PENINSULA TOMORROW AND WEAKEN THROUGH
WEDNESDAY.

.MODEL DISCUSSION...
GREAT RUN TO RUN CONSISTENCY WITH THE GFS THIS MORNING THROUGH
THURSDAY. THESE ARE IN LINE WITH THE 12Z ECMWF AND THE GFS ENSEMBLE
MEAN. HOWEVER...THE ECMWF SWINGS A LOW IN THE GULF ON WEDNESDAY TOO
FAST BACK TO BRISTOL BAY. THE GFS ON THE OTHER HAND IS SLOWER AND THE
LOW REMAINS IN THE GULF AND COMBINES WITH ANOTHER LOW ON FRIDAY. THE
ECMWF AND GFS ARE SIMILAR AT THIS POINT. AFTER THIS POINT...SOME
LARGE DIFFERENCES APPEAR. THE CURRENT RUN OF THE GFS AND THE 00Z RUNS
OF THE ECMWF AND GFS HAD A LOW TRAVELING ACROSS THE WESTERN BERING
AND ALEUTIAN CHAIN SATURDAY THROUGH MONDAY AND DIVING TO THE GULF
LOW.

OVERALL...MEAN TROUGH REMAINS OVER ALASKA THROUGH THE NEXT WEEK.

.UPPER LEVELS...
BROAD TROUGH OVER THE MAINLAND TODAY WITH A RIDGE OVER THE WESTERN
BERING. AN UPPER LEVEL LOW NEAR BETHEL TO SLIP INTO THE GULF TOMORROW
AND BRING COLDER AIR ACROSS KODIAK AND SUPPORT THE LOW IN THE GULF
FURTHER. IN THE MEANTIME...A SHORT WAVE TROUGH RIDING A JET CORE FROM
THE WESTERN ALEUTIANS TO THE EASTERN ALEUTIANS TO MOVE FROM SHEMYA
THIS AFTERNOON TO SOUTH OF COLD BAY TOMORROW AFTERNOON. THIS WAVE TO
DIVE INTO THE GULF AND MEET WITH THE GULF LOW WEDNESDAY AND WRAP
AROUND THE GULF THURSDAY. ANOTHER SHORT WAVE TO WRAP INTO THIS SYSTEM
AS WELL THURSDAY/FRIDAY.

.SHORT TERM FORECAST...
ALEUTIANS AND BERING...
STRONG NORTHWEST FLOW OVER THE CENTRAL AND EASTERN BERING. COMBINED
WITH SNOW SHOWERS...AREAS OF BLOWING SNOW REDUCING VISIBILITIES.
THESE CONDITIONS TO REMAIN THROUGH THE NEXT COUPLE DAYS. FURTHER
WEST...A LOW WEST OF SHEMYA TO SLIDE THROUGH THE ALEUTIANS TONIGHT
AND TOMORROW. ANOTHER LOW TO FOLLOW THE SAME PATH WEDNESDAY. BOTH
LOWS FEED INTO THE MEAN GULF LOW.

WESTERN ALASKA...
LOW IN THE GULF COMBINED WITH MEAN HIGH IN THE WESTERN BERING
CREATING MODERATE NORTHWEST FLOW OVER WESTERN ALASKA. AN UPPER LOW
OVER THE AREA CREATING CONCENTRATED AREAS OF SNOW. COMBINED WITH THE
WINDS...BLOWING SNOW HAS REDUCED VISIBILITIES ALONG THE COASTAL
LOCATIONS. FURTHER INLAND...SCATTERED SNOW SHOWERS PREVAIL. THESE
CONDITIONS THROUGH TONIGHT. THE ACTIVITY THEN TURNS MORE SHOWERY AS
VORT MAX AFTER VORT MAX ROTATE AROUND THE MEAN TROUGH INLAND OVER THE
NEXT COUPLE DAYS.

SOUTH CENTRAL ALASKA...
LOW IN THE NORTHERN GULF BRINGING SNOW TO THE EASTERN SOUND AND
COPPER RIVER BASIN. DRIER NORTHWEST FLOW WEST OF THAT KEEPING SNOW
FROM SPREADING WEST. THE LOW TO MOVE INLAND NEAR SEWARD TONIGHT WITH
SOME SNOW WORKING TO THE WESTERN SOUND AND OVER THE EASTERN KENAI
PENINSULA. AS THE FLOW TURNS MORE EASTERLY ALOFT TOMORROW AND
TOMORROW NIGHT...SNOW SHOWERS WILL WORK OVER THE KENAI MOUNTAINS AND
INTO THE WESTERN KENAI. SOME OF THESE SHOWERS MAY MOVE INTO THE
ANCHORAGE AREA AS WELL. MODERATE NORTHWEST FLOW OVER THE SOUTHERN AND
WESTERN GULF...TO KEEP SHOWERS AND COLDER AIR THERE. FREEZING SPRAY
COULD BECOME A PROBLEM IN SHELIKOF AND THE BARREN ISLANDS. THIS LOW
TO WEAKEN WEDNESDAY AS ANOTHER LOW WRAPS UP THE EASTERN GULF AROUND
TO KODIAK THURSDAY. YET ANOTHER LOW FEEDS INTO THE SOUTHERN GULF
FRIDAY.

.LONG TERM FORECAST...
ANCHOR LOW IN THE GULF WITH HIGH PRESSURE GENERALLY OVER THE WESTERN
BERING. THIS WOULD MEAN A COLD MAINLAND AIR MASS WITH A ANCHOR LOW IN
THE GULF AND HIGH PRESSURE OVER THE WESTERN ALEUTIANS. MODERATE TO
STRONG NORTHWEST FLOW OVER THE CENTRAL AND EASTERN BERING CAN BE
EXPECTED THROUGH THIS TIME FRAME.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...BLIZZARD WARNING ZONE 181
MARINE...GALE 130 150 155 165
         HEAVY FREEZING SPRAY 150 155 160 165 179 185
FIRE WEATHER...NONE

JN MAR 08

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ANCHORAGE AK
1113 PM ADT MON MAR 17 2008

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

0256 AM     BLIZZARD         KING COVE               55.06N 162.30W
03/17/2008                                      AK   ASOS

            BLIZZARD CONDITIONS WERE MET FROM 3AM THROUGH NOON TODAY
            IN KING COVE AND THE COLD BAY AREA. VISIBILITY DROPPED
            WELL BELOW 1/4 MILE AND WINDS PEAKED AT OVER 70 MPH.

&&

SSHEA