Small Craft Advisory 1101, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 AM AST SAT DEC 29 2007

.MODEL DISCUSSION...
MODELS IN REASONABLE AGREEMENT. AGAIN A PREFERENCE FOR GFS EXCEPT
OVER AND/OR NEAR LAND WHERE NAM WAS BLENDED IN. GFS AND ECMWF HIGH
RESOLUTION RUNS IN FAIR AGREEMENT THROUGH ABOUT 200 HOURS...AT LEAST
FOR THE LARGE SCALE FEATURES.

.ANALYSIS AND UPPER LEVELS...
MEAN STEERING UPPER LOW OVER THE BERING SEA WITH ANOTHER LOW OVER
THE NORTHER GULF. UPPER RIDGE STRETCHING FROM BRITISH COLUMBIA
THROUGH THE YUKON AND CENTRAL ALASKA...THEN NORTH TO THE POLE.
STRONG SUBTROPICAL RIDGE DIRECTLY SOUTH OF THE GULF LOW. SHORT WAVE
TROUGH SOUTH OF THE CENTRAL ALEUTIANS THIS MORNING MOVING
EAST...HELPED ALONG BY THE SUBTROPICAL JET THAT IS RACING ACROSS THE
PACIFIC SOMEWHAT ZONALLY AROUND 45 DEGREES NORTH LATITUDE. POLAR JET
WEAK AND BROKEN UP ACROSS THE NORTHERN HEMISPHERE...A HINT OF IT
MOVING NORTH ALONG WESTERN ALASKA THEN SPLITTING EAST/WEST JUST
SOUTH OF THE ARCTIC OCEAN.

.SHORT TERM FORECAST...
GULF LOW WILL MOVE EAST TODAY AND WILL SLIDE SOUTHEAST AND OUT OF
THE AREA BY SUNDAY MORNING. LEFT OVER MOISTURE PROVIDING AREAS OF
SNOW IN SOUTH CENTRAL TODAY ALONG A DEFORMATION ZONE. SOME RIDGING
ON SUNDAY OVER THE GULF AHEAD OF THE LOW CURRENTLY SOUTH OF THE
ALEUTIANS AS IT MOVES EAST. THIS LOW WILL THEN TAP THE SUBTROPICAL
JET AND A SURFACE LOW WILL BOMB OUT EARLY MONDAY...THE GFS
FORECASTING A 956 MB LOW OVER THE CENTRAL GULF BY MONDAY AFTERNOON.
THIS WILL HELP PUSH THE BRITISH COLUMBIA/YUKON RIDGE INTO SOUTH
CENTRAL ALASKA ON MONDAY.

.LONG TERM FORECAST...
EXPECT SEASONABLE TEMPERATURES AND PRECIPITATION ACROSS SOUTH
CENTRAL AND SOUTHWEST ALASKA FROM THE MIDDLE OF THE WEEK INTO THE
WEEKEND AS THE RIDGE WEAKENS AND THE AREA IS IN A COL (WEAK UPPER
FLOW BETWEEN TWO HIGHS AND TWO LOWS). SEASONABLE WEATHER OVER THE
BERING SEA AND ALEUTIANS ALSO AS THE MAIN JET STREAM NUDGES NORTH
INTO THE AREA.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE WARNING 120 130 132 150 155 165 170 185.
         HVY FRZ SPRY 121 129 130 132 138 140 141 160 165 180 185.
FIRE WEATHER...NONE.

LUDWIG DEC 07