Small Craft Advisory 450, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 AM AKDT TUE JUN 2 2009

.ANALYSIS AND UPPER LEVELS...
IN THE UPPER LEVELS...THE RIDGE OVER THE EASTERN GULF REMAINS WELL
ENTRENCHED...WITH A HIGH AMPLITUDE TROUGH OVER THE BERING SEA AND
ALEUTIANS. STRONG SOUTHERLY FLOW EXISTS BETWEEN THESE
SYSTEMS...STREAMING MOIST AIR INTO SOUTHWESTERN AK.

AT THE SURFACE...HIGH PRESSURE IS IN FIRM CONTROL OVER THE CENTRAL
GULF AND SOUTHCENTRAL. A BROAD LOW COMPLEX IS CENTERED SOUTH OF THE
CENTRAL ALEUTIANS. MOIST SOUTHERLY FLOW IS EVIDENT ON WATER VAPOR
IMAGERY...SPREADING RAIN INTO THE SOUTHWESTERN MAINLAND AND THE
AKPEN.

.MODEL DISCUSSION...
MODELS ARE IN SATISFACTORY AGREEMENT THROUGH WEDNESDAY...WITH THE
SURFACE HIGH STAYING OVER THE GULF AND A LOW COMPLEX OVER THE BERING
SEA AND CENTRAL ALEUTIANS. DIFFERENCES IN MODEL SOLUTIONS ARISE
CONCERNING THE TRACK AND INTENSITY OF INDIVIDUAL LOWS WITHIN THE LOW
COMPLEX TOWARDS THE END OF THE WEEK. THE GFS SOLUTION WAS USED TO
CONSTRUCT THE MORNING FORECAST PACKAGE...WITH RELATIVELY LITTLE
CHANGE TO THE ONGOING FORECAST.

.SHORT TERM FORECAST...
.SOUTHCENTRAL...
HIGH PRESSURE OVER THE REGION WILL RESULT IN GENERALLY FAIR
CONDITIONS OVER THE NEXT SEVERAL DAYS. OVER THE COPPER RIVER
BASIN...TEMPERATURES APPROACHING EIGHTY DEGREES AND DRY AIR WILL
RESULT IN EXTREME FIRE DANGER. ACCORDINGLY...A RED FLAG WARNING IS IN
PLACE FOR TODAY. ELSEWHERE...AS THE SURFACE HIGH PUSHES
WESTWARD...CONDITIONS WILL BE IMPROVING FOR KODIAK ISLAND AND WESTERN
COOK INLET. ONE OTHER CONCERN THAT WILL HAVE TO BE MONITORED IS HOW
FAR INLAND THE MARINE LAYER WILL PENETRATE...WITH LOW STRATUS AND FOG
BEING THE PRIMARY PROBLEMS.

.SOUTHWEST...
MOIST SOUTHERLY FLOW WILL KEEP THE THREAT OF RAIN ACROSS THE AREA
THROUGH THURSDAY. CONDITIONS WILL BEGIN IMPROVING TUESDAY NIGHT INTO
WEDNESDAY...AS SURFACE HIGH PRESSURE OVER SOUTHCENTRAL SPREADS
WESTWARD. CONDITIONS WILL BEGIN DETERIORATING ACROSS THE AKPEN AND
BRISTOL BAY AGAIN LATE WEDNESDAY AS AN OCCLUDED FRONT MOVES IN FROM
THE SOUTH.

.BERING SEA AND ALEUTIANS...
THE LOW COMPLEX WILL KEEP LOW CEILINGS...FOG...AND RAIN AROUND THE
ALEUTIANS AND PRIBILOFS THROUGH THE NEXT SEVERAL DAYS. THE WESTERN
ALEUTIANS WILL REMAIN DRIEST AS THE BULK OF THE MOISTURE ASSOCIATED
WITH THE LOW REMAINS FARTHER TO THE EAST.

.LONG TERM FORECAST...
THE UPPER RIDGE IS EXPECTED TO REMAIN OVER THE GULF OF
ALASKA...KEEPING GENERALLY FAIR WEATHER OVER SOUTHCENTRAL THROUGH THE
END OF THE WEEK. THE ALEUTIANS AND SOUTHWEST ALASKA WILL REMAIN UNDER
THE INFLUENCE OF A LARGE TROUGH...KEEPING WEATHER UNSETTLED AS WE
HEAD INTO THE WEEKEND.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE
MARINE...GALE 155
FIRE WEATHER...RED FLAG WARNING 141

NRH JUN 09