Small Craft Advisory 236, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 PM AST FRI MAR 18 2005

.DISCUSSION...
ANALYSIS - A MAJOR UPPER RIDGE WITH A HIGH CENTER NEAR KODIAK IS OVER
SW ALASKA THIS MORNING WITH AN EXTENSION TOWARD BANKS ISLAND. A MAJOR
UPPER LOW IS OVER 46N 168W AT 12Z FRI OVER A 990 MB GALE FORCE
CENTER. THE OCCLUDED FRONT HAS STALLED AROUND 50N AT 18Z WITH A WARM
FRONT GONE ALOFT OVER THE CENTRAL BERING SEA. OTHER THAN 250 MB WINDS
AROUND THE UPPER RIDGE AROUND 80 KNOTS...A WESTERLY JET IS PERSISTENT
ALONG 30N. A 1043 MB HIGH CELL IS OVER NW CANADA THIS MORNING WITH A
SURFACE RIDGE EXTENDING INTO SIBERIA.

AER FORECASTS - THE MODEL SOLUTIONS ARE AGAIN IN EXCELLENT AGREEMENT
THIS MORNING ALL FORECASTING A CLOSED UPPER HIGH CENTER OVER SW
ALASKA SAT THAT MOVES OVER PACD SAT NIGHT. THIS SETS UP OFFSHORE FLOW
FOR ALMOST THE ENTIRE FORECAST AREA WITH DRY CONDITIONS AND
SIGNIFICANT DIURNAL TEMPERATURE VARIATION. WE ARE STILL KEEPING AN
EYE ON A POSSIBLE WIND EVENT DEVELOPING SUN NIGHT AS A SHORTWAVE
DROPS DOWN THE ALCAN SIDE AND LOW PRESSURE DEVELOPS IN THE
GULF. THE STRONGEST WINDS WILL BE FOR THE EASTERN SECTIONS LIKE
VALDEZ AND THE COPPER RIVER DELTA ALTHOUGH SOME SIGNIFICANT N WIND
WILL ALSO DEVELOP WILL BLOWING DUST FOR THE REST OF THE AER AREA.
THE ETA MODEL IN AWIPS HANDLES THE SURFACE PRESSURE GRADIENTS BEST IN
AN EVENT LIKE THIS ONE. WE WILL ALSO LOOK AT THE RAMMS AND MM5 AS WE
GET CLOSER TO THE EVENT.

ALU FORECASTS - LOOK FOR THE LOW S OF THE EASTERN ALEUTIANS TO
CONTINUE TO WEAKEN WITH LOW LEVEL OFFSHORE FLOW FOR THE SW COAST.
WITH THE UPPER HIGH OVER COLD BAY 12Z SUN...THE STRONG S FLOW ALOFT
THAT DEVELOPS ON THE BACK SIDE OF THE HIGH REMAINS W OF 175W INTO
MON. A STRONG FRONT WILL MOVE INTO THE WESTERN ALEUTIANS TONIGHT FROM
A STORM NEAR THE KURILES WITH A SECONDARY LOW FORMING S OF THE
CENTRAL ALEUTIANS SUN. OFFSHORE FLOW WILL BE THE BIG DEAL FOR THE SW
ALASKA COAST INTO THE BERING SEA THROUGH MON.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...WIND ADVISORY 131 161 181 185 187 191.
MARINE...GALES 155 165 170 175 176 180.
FIRE WEATHER...NONE.

JC MAR 05