FXAK68 PAFC 061250
AFDAFC

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
450 AM AKDT SAT SEP 6 2008

.ANALYSIS AND UPPER LEVELS...DEEP UPPER TROUGH SITUATED FROM THE
EASTERN BERING INTO THE NORTH CENTRAL PACIFIC WITH AN INTENSIFYING
LOW NEAR 50N 160W. A LONG FETCH OF TROPICAL MOISTURE IS STREAMING
NORTH AHEAD OF THE TROUGH SPELLING PLENTY OF RAIN FOR COASTAL
LOCATIONS OF SOUTHCENTRAL OVER THE WEEKEND. A SECONDARY TROUGH OVER
THE WESTERN ALEUTIANS WILL SLIDE IN BEHIND THE FIRST LOW WITH A
CONTINUED SOUTHWEST FLOW FOR THE SOUTHERN MAINLAND.

.MODEL DISCUSSION...THE GFS HAS BEEN PRETTY CONSISTENT AND HAS
FINALLY FALLEN IN LINE WITH THE ECMWF IN THE LATTER PERIODS. ONLY
MINOR TWEAKS WERE NEEDED IN THE SHORT TERM WITH A FULL RELOAD WITH
THE LATEST GFS FROM TUESDAY THROUGH NEXT SATURDAY.

.SHORT TERM FORECAST...THE LOW NEAR 50N 160W WILL BOTTOM OUT AROUND
986 MB THIS AFTERNOON AS IT MOVES TOWARD THE SOUTHERN END OF KODIAK
ISLAND BY SUNDAY MORNING. PLENTY OF GALE FORCE WINDS CAN BE EXPECTED
AS THIS LOW AND ITS ASSOCIATED FRONT LIFT NORTHWARD. GUSTY E-W GAP
WINDS WILL INCREASE THIS AFTERNOON ACROSS SOUTHCENTRAL AND SW ALASKA
AS THE FRONT APPROACHES...TIGHTENING THE PRESSURE GRADIENT. HEAVY
RAIN (AS MUCH AS 2 INCHES PLUS) IS EXPECTED FROM KODIAK ISLAND TO THE
EASTERN KENAI PENINSULA AND WESTERN PRINCE WILLIAM SOUND. WITH
SATURATED GROUND AND RIVERS RUNNING HIGH FROM RAINS LAST WEEK...ZONE
125 (WESTERN PRINCE WILLIAM SOUND) IS UNDER A FLOOD WATCH. THE
INITIAL SURGE OF MOISTURE SHOULD MAKE IT A WAYS INLAND WITH PERIODS
OF LIGHT RAIN BEFORE DOWNSLOPE WINDS KICK IN ERNEST LATER TONIGHT.
THE BRISTOL BAY REGION WILL SEE RAIN ENCROACH FROM THE SOUTH THIS
AFTERNOON...CONTINUING INTO THE KUSKOKWIM VALLEY TONIGHT. THE
STEADIER RAINS WILL GIVE WAY TO A SHOWERIER REGIME ON SUNDAY AS THE
ENTIRE SYSTEM MOVES INLAND AND WEAKENS.

ANOTHER LOW RIDING AROUND THE BACKSIDE OF THE BERING SEA TROUGH WILL
SKIRT SOUTH OF THE ALEUTIANS AND EMERGE JUST WEST OF ITS PREDECESSOR
CROSSING THE AKPENN SOMETIME ON MONDAY. SIMILAR CONDITIONS CAN BE
EXPECTED WITH THIS SYSTEM...MEANING MORE E-W GAPS WINDS WITH PLENTY
OF GALES IN THE MARINE ZONES (BOTH AHEAD AND BEHIND THE LOW) AND OF
COURSE PLENTY OF RAIN.

.LONG TERM FORECAST...A TROUGH IS EXPECTED TO PERSIST IN THE EASTERN
BERING...WHICH SPELLS MORE OF THE SAME...WET AND WINDY THROUGH AT
LEAST MID-WEEK.


.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...FLOOD WATCH 125.
MARINE...GALE 120 125 130 132 138 140 150 155 160 165 351 352.
FIRE WEATHER...NONE.

JCA
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