Small Craft Advisory 858, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
200 PM AKDT FRI NOV 1 2013

.ANALYSIS AND UPPER LEVELS...
THERE IS AN UPPER LEVEL LOW OVER THE CENTRAL ALEUTIANS WITH THE
LEADING FRONTAL BAND PUSHING INTO THE ALASKA PENINSULA. THERE IS
ANOTHER LOW SOUTHWEST OF THE WESTERN ALEUTIANS AND MOVING EAST. A
WEAK SHORT-WAVE TROUGH IS CROSSING SOUTH CENTRAL ALASKA.

.MODEL DISCUSSION...
THE NUMERICAL MODELS ARE IN FAIRLY GOOD AGREEMENT. AFTER 60 HOURS
INTO THE FORECAST THE ECMWF IS MORE INSISTENT THAN THE OTHER MODELS
IN DEVELOPING A SURFACE LOW ALONG THE FRONT IN THE GULF...AND
FURTHER EAST. THIS MAKES SENSE CONSIDERING THE THE MORE SOUTHERLY
JET LOCATION. THE ECMWF WAS THE MODEL OF CHOICE. CONFIDENCE IN THE
FORECAST IS NEAR NORMAL DUE TO THE GENERAL AGREEMENT ON THE MODELS
OFFSET BY THE DISAGREEMENT ON THE GULF LOW DEVELOPMENT.

.SHORT TERM FORECAST...
FOR SOUTH CENTRAL ALASKA...THE UPPER LEVEL SHORT-WAVE TROUGH WILL
WEAKEN AS IT CROSSES THE AREA TONIGHT. SNOW LEVELS WILL DROP WITH
THIS SYSTEM BUT ACCUMULATIONS (IF ANY) WILL MAINLY BE LIMITED TO
HIGHER ELEVATIONS AND INLAND AREAS. A FRONT ASSOCIATED WITH THE
ALEUTIAN/BERING LOW WILL PUSH INTO SOUTH CENTRAL ON SATURDAY AND
SATURDAY NIGHT. THIS FRONT WILL BE WEAKENING AS ITS PARENT LOW FILLS
AND LOSES ITS JET SUPPORT. THIS WILL BE A FAIRLY "STANDARD" SYSTEM
WITH WINDY CONDITIONS NEAR THE COAST AND THROUGH TURNAGAIN ARM...AND
MOST OF THE PRECIPITATION ALONG THE COAST AND MOUNTAINS WITH LITTLE
EXPECTED INLAND. ANOTHER SYSTEM (THE ONE CURRENTLY SOUTHWEST OF THE
WESTERN ALEUTIANS) WILL MOVE INTO THE AREA SUNDAY NIGHT AND MONDAY.
THIS WILL BE A LITTLE STRONGER THAN THE PREVIOUS SYSTEM...BUT
NOTHING OUT OF THE ORDINARY FOR THIS TIME OF YEAR.

FOR SOUTHWEST ALASKA...THE ALEUTIAN LOW WILL MOVE NORTHEAST INTO THE
BERING SEA TONIGHT. FRONTAL WINDS AND PRECIPITATION WILL REACH THE
COAST LATE TONIGHT AND PUSH INLAND ON SATURDAY. THE MAIN UPPER LOW
WILL WEAKEN AS IT MOVES NORTH...REACHING NORTON SOUND ABOUT THE TIME
IT DISSIPATES LATE SATURDAY NIGHT. FLOW ALOFT WILL CONTINUE FROM THE
SOUTHWEST THROUGH THE WEEKEND...KEEPING THINGS SOMEWHAT CLOUDY AND
MOIST. THE NEXT SYSTEM WILL PUSH INTO THE AREA LATE SUNDAY AND THEN
MOVE EAST ON MONDAY.

FOR THE BERING SEA AND ALEUTIANS...THE SYSTEM CURRENTLY CENTERED
OVER THE CENTRAL ALEUTIANS WILL BEGIN TO WEAKEN TONIGHT...THEN
CONTINUE THAT TREND AS IT MOVES NORTH/NORTHEAST AND THEN DISSIPATES
SATURDAY NIGHT. THE NEXT SYSTEM WILL MOVE INTO THE CENTRAL ALEUTIANS
SATURDAY AFTERNOON THEN INTO THE EASTERN BERING SEA AND ALASKA
PENINSULA SATURDAY NIGHT. THIS LOW WILL THEN TRACK EAST AND PUSH
INTO THE GULF ON MONDAY.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...STORM WARNING 172 174 176.
         GALE WARNING 130 150 155 160 165 170 171 173 175 177 178
                        179 180 181 185.
FIRE WEATHER...NONE.

LUDWIG NOV 13