Small Craft Advisory 761, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
200 PM ADT SUN SEP 16 2007

.MODEL DISCUSSION...MODELS COMING INTO BETTER AGREEMENT IN REGARDS TO
THE NEXT MAJOR STORM FROM THE NORTH PACIFIC. THE LATEST GFS AND ECMWF
ARE VERY CLOSE IN BOTH PLACEMENT AND STRENGTH OF THIS LOW BARRELING
INTO THE BERING SEA ON TUES. IN THE NEAR TERM...A RESIDUAL LOW NEAR
YAKUTAT WITH AN UPPER SHORTWAVE STRETCHING BACK TO THE WEST WILL
SLOWLY SLIDE SE OVERNIGHT. BOTH THE NAM AND GFS DONT RESOLVE THE LOW
VERY WELL TO BEGIN WITH...BUT THIS HAS LITTLE IMPACT ON THE FORECAST.

.ANALYSIS AND UPPER LEVELS...HIGH PRESSURE OVER BRISTOL BAY WILL BE
SHIFTING EAST AS SOUTHWEST FLOW ALOFT SETS UP IN RESPONSE TO THE
DEEPENING LOW SOUTH OF SHEMYA. THE SHORTWAVE OVER THE COPPER RIVER
WILL BE SLOW TO PULL AWAY OVERNIGHT KEEPING CLOUDS AND PRECIP AROUND
FOR A BIT LONGER. ANOTHER UPPER WAVE NEAR ST. MATTHEW ISLAND WILL
CRASH ONTO THE COAST OF SOUTHWEST ALASKA THIS EVENING THEN SLOWLY
TRAVERSE ALONG THE ALASKA RANGE THRU MON NITE.

.SHORT TERM FORECAST...STORM FORCE WINDS AND PLENTY OF RAIN TO IMPACT
THE ALEUTIANS BEGINNING TONIGHT. THE OCCLUDED FRONT WILL PASS THROUGH
THE WESTERN ALEUTIANS TONIGHT AND WORKS ITS WAY TO BRISTOL BAY BY
EARLY TUESDAY. AS THE LOW CROSSES THE CHAIN NEAR ADAK MON NITE...A
POTENT 150 KT+ JET STREAK ROUNDS THE BASE OF THE ASSOCIATED UPPER
TROUGH SETTING THE STAGE FOR THE POTENTIAL FOR HIGH WINDS. THUS A
HIGH WIND WATCH WILL BE HOISTED FOR ZONE 187 FOR MON NITE AS THE GFS
SHOWS UNIDIRECTIONAL WINDS UP TO 500 MB WITH BOUNDARY LAYER WINDS OF
55-60 KTS. THE FRONT WEAKENS AS IT CRASHES ONSHORE...BUT SOUTHWEST
ALASKA WILL SEE PLENTY OF WIND AND RAIN.

FURTHER EAST...AS MENTIONED BEFORE...RAIN AND CLOUDS WILL BE SLOW TO
CLEAR OUT OF THE COPPER RIVER BASIN OVERNIGHT AS AN UPPER SHORTWAVE
SLIDES SLOWLY SE. CLEARING SKIES FURTHER TO THE WEST OVER
SOUTHCENTRAL IS GOING TO LEAD TO A COLD NIGHT. IN FACT...THE FIRST
FROST...OR DARE I SAY FREEZE MAY OCCUR. WE WILL ISSUE A SPECIAL
WEATHER STATEMENT TO ALERT FOLKS TO THIS POSSIBILITY BOTH IN
ANCHORAGE AND THE VALLEY.

THE FRONT FROM THE LOW IN THE BERING WILL SWEEP ACROSS KODIAK ISLAND
MON NITE AND OVERTAKE MOST OF SOUTHCENTRAL BY DAYS END ON TUE. WINDS
THROUGH E-W GAPS INCLUDING TURNAGAIN ARM WILL CRANK UP BY EARLY TUE
AS HEAVY RAINS INUNDATE COSTAL LOCATIONS.

.LONG TERM FORECAST...THE JET STREAM IS SET UP TO CONTINUE STEERING
NORTH PACIFIC LOWS INTO THE BERING SEA.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...HIGH WIND WATCH 187.
MARINE...GALE 155 160 165 180 170 171 185 179.
         STORM 172 175 176.
FIRE WEATHER...NONE.

JCA

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE ANCHORAGE AK
1 PM ADT SUN SEP 16 2007

AKZ101-111-145-170800-

...POTENTIAL FROST FOR PARTS OF ANCHORAGE AND THE MATSU VALLEY
TONIGHT...

MOSTLY CLEAR SKIES AND LIGHT WINDS TONIGHT WILL SET THE STAGE FOR
QUICKLY DROPPING TEMPERATURES AFTER SUNSET AND NEAR FREEZING
TEMPERATURES. AT GREATEST RISK ARE AREAS IN EAST ANCHORAGE AND
LOW-LYING AREAS.

IT IS STRONGLY RECOMMENDED TO BRING PLANTS INDOORS TONIGHT. THOSE
WITH AGRICULTURAL INTERESTS ARE ADVISED TO TAKE NECESSARY
PRECAUTIONS.