Small Craft Advisory 345, NWS Anchorage, AK

AREA FORECAST DISCUSSION...UPDATED
SOUTHCENTRAL AND SOUTHWEST ALASKA
527 AM AKDT TUE APR 21 2009

.MODEL DISCUSSION...MODELS ARE GENERALLY IN VERY GOOD AGREEMENT
THROUGH THE WEEKEND. THE BIGGEST AREA OF DIFFERENCES INVOLVE A
POSSIBLE TRIPLE POINT LOW THAT DEVELOPS NEAR COLD BAY ON THURSDAY AND
THEN EITHER HEADS UP THE BRISTOL BAY COAST OR TRACKS INTO
SOUTHCENTRAL. THE GFS HAS CHANGED TO THE MORE EASTERLY TRACK THAT IS
AGREED UPON BY THE EC AND THE NAM. HOWEVER THE GFS REMAINS AN OUTLIER
WITH RESPECT TO THE INTENSITY OF THIS FEATURE AS IT IS THE ONLY MODEL
THAT DEVELOPS A STRONG CLOSED LOW. AT THIS TIME PREFER A GFS-LIKE
TRACK BUT WILL DIMINISH THIS FEATURE TO AN OPEN WAVE THAT MOVES OVER
THE KENAI PENINSULA THURSDAY NIGHT AND FRIDAY MORNING.

.ANALYSIS AND UPPER LEVELS...THE TROUGH-RIDGE-TROUGH PATTERN OF THE
LAST SEVERAL DAYS REMAINS INTACT AS EVERYTHING SLIDES TO THE EAST.
THE JET...ALBEIT WEAK AT LESS THAN 100 KT...CONTINUES TO TRAVEL UP
AND OVER THE RIDGE THAT IS NOW IN THE EASTERN BERING SEA. THIS IS
MAKING FOR MOSTLY CLEAR SKIES FOR MAINLAND ALASKA. THE FRONT IN THE
BERING SEA IS BETWEEN ATKA AND DUTCH HARBOR AND IS BRINGING
INCREASING SOUTHEASTERLY WINDS TO THE EASTERN ALEUTIANS AND STRONG
GALE-FORCE WINDS TO THE CENTRAL AND EASTERN BERING.

.SHORT TERM FORECAST...
.EAST OF THE ALASKA RANGE...ANOTHER SUNNY AND WARM DAY IS ON TRACK
FOR THE ENTIRE AREA TODAY. PRIMARY FORECAST CHALLENGE WILL CONTINUE
TO BE GAP WINDS THROUGH THE FAVORED AREAS TODAY INCLUDING COPPER
RIVER DELTA...THOMPSON PASS...RESURRECTION BAY...AND THE BARREN
ISLANDS. WIND SPEEDS SHOULD BE ON THE SLOW DECLINE TODAY AS LINGERING
TROUGH IN THE NORTHERN GULF RETREATS AND A COL MOVES INTO THE AREA
FROM THE WEST. MODELS AGREE THAT THE ORIGINAL BERING FRONT WILL NOT
MAKE IT TO SOUTHCENTRAL...HOWEVER THE AFOREMENTIONED WAVE THAT
DEVELOPS AND RIDES UP THE FRONT WILL BRING THE FIRST SHOT OF PRECIP
TO SOUTHCENTRAL STARTING THURSDAY AFTERNOON.

.WEST OF THE ALASKA RANGE...ANOTHER NICE DAY ON TRACK FOR TODAY EVEN
AS HIGH CLOUDS SPREAD INTO SOUTHWEST ALASKA. WINDS WILL BEGIN TO
INCREASE ON THE COAST THIS AFTERNOON AND PRECIP ARRIVES TONIGHT.
TEMPS WILL BE WARM ENOUGH WITH THIS SYSTEM THAT RAIN... OR A MIX OF
RAIN AND SNOW... SHOULD OCCUR OVER BRISTOL BAY. A MIX OF RAIN AND
SNOW IS LIKELY OVER THE DELTA WITH ANY SNOW ACCUMULATIONS BEING VERY
MINIMAL. ALL WINDS TODAY AND TONIGHT ARE EXPECTED TO REMAIN BELOW
STORM FORCE EXCEPT OVER THE EASTERN ALEUTIANS WHERE MINIMUM STORM
FORCE WINDS ARE LIKELY TODAY.

.LONG TERM FORECAST...PARENT LOW OF BERING SEA FRONT LINGERS AND
SLOWLY WEAKENS IN THE NORTHERN BERING THROUGH THE END OF THE WEEK
BEFORE NEXT STRONG LOW ARRIVES THURSDAY NIGHT AT THE WESTERN
ALEUTIANS.  FOR THE MAINLAND...BROAD SOUTHWEST FLOW LOOKS TO CONTINUE
THROUGH NEXT WEEK BRINGING SEASONAL TEMPERATURES AND ABOVE AVERAGE
PRECIPITATION TO MOST LOCATIONS.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...STORM 170
         GALE 155 160 165 171 172 176 179 180 185
FIRE WEATHER...NONE.

AMD APR 09