Small Craft Advisory 747, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
200 PM ADT SAT SEP 17 2005

.DISCUSSION...WEAK FRONT ALONG THE NORTHERN GULF COAST WITH
PRECIPITATION BECOMING MORE SCATTERED OVER SOUTH CENTRAL. STRONG LOW
IN THE GULF OF ALASKA THIS AFTERNOON NEAR EXIT REGION OF 150 KT JET
AND GOOD VORTICITY ADVECTION. COLD POCKET WITH LOW ALSO ADDING TO
DEEPENING OF LOW THIS MORNING. OLD UPPER LEVEL PARENT LOW NEAR SAINT
LAWRENCE ISLAND WITH WEAK SURFACE LOW STACKED UNDERNEATH. THE JET TO
RACE ACROSS THE GULF TONIGHT PULLING SURFACE LOW WITH IT. THE LOW
MAINTAINS ITS STRENGTH AS IT CROSSES THE GULF WITH STORM FORCE WINDS
JUST SOUTH OF IT AND GALES WRINGING IT. THE LOW FILLS AS THE JET
PUSHES INLAND FASTER THAN THE SURFACE LOW. IN ADDITION...THE AIR
MODERATES WITH THE LOW DRAINING ENERGY FROM THE LOW. PRECIPITATION TO
REMAIN ALONG THE GULF COAST AND WITH THE LOW. AIR MASS OVER THE
REMAINDER OF THE MAINLAND RELATIVELY UNSTABLE WITH JUST ISOLATED TO
SCATTERED SHOWERS. SHOWERS MORE PREVALENT NEAR THE MOUNTAINS. WITH
ONSHORE FLOW ALONG THE WEST COAST AND BERING SIDE OF THE
ALEUTIANS...SCATTERED SHOWERS WILL EXIST THERE AS WELL.

BY SUNDAY AFTERNOON...BROAD TROUGH REIGNS OVER THE MAINLAND WITH A
SHORT WAVE RIDGE OVER THE WESTERN ALEUTIAN CHAIN. MODERATE TO STRONG
NORTHWEST TO WEST WINDS WILL BE PREVALENT FROM THE CENTRAL ALEUTIANS
TO THE GULF. THIS WILL PERSIST THROUGH MONDAY. WINDS OVER THE LAND
WILL REMAIN MOSTLY LIGHT THROUGH MONDAY. SCATTERED SHOWERS WILL
PERSIST ALONG THE WEST COAST OF ALASKA...MAINLAND MOUNTAINS...AND
BERING SIDE OF THE EASTERN ALEUTIANS.

ANOTHER LOW PUSHES TO THE WESTERN ALEUTIANS MONDAY FORCING THE RIDGE
INTO THE EASTERN ALEUTIAN CHAIN. AS THIS SURFACE AND ASSOCIATED UPPER
LEVEL LOW MOVES INTO THE BERING SEA...THE TROUGH OVER THE MAINLAND IS
REPLACED BY A WEAK RIDGE TUESDAY NIGHT. GALE FORCE WINDS TO ACCOMPANY
THIS LOW OVER THE WESTERN BERING AND ALEUTIANS. WHEN THIS LOW PUSHES
INTO THE CENTRAL BERING SEA...A FRONT WILL WORK TO THE WEST COAST OF
ALASKA. THE WEAKENING FRONT WILL CONTINUE TO SOUTH CENTRAL ALASKA AND
ACROSS THE MAINLAND THURSDAY. IN ADDITION...A STRONG SHORT WAVE WILL
ROTATE THROUGH THE BASE OF THE LOW WITH A 150 KT JET. THIS WILL
DEVELOP A LOW ALONG THE ALEUTIAN CHAIN TO PUSH MUCH LIKE THE CURRENT
SYSTEM ACROSS THE AKPEN THURSDAY AND INTO THE GULF THURSDAY NIGHT.
THIS WILL LIKELY BRING GALE FORCE WINDS THROUGH THE ALEUTIANS AND
TOWARD THE GULF THURSDAY NIGHT.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE
MARINE...GALE 120 132 150 155 170
FIRE WEATHER...NONE

JN SEP 05