Small Craft Advisory 909, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
200 PM ADT MON OCT 29 2007

.MODEL DISCUSSION...GFS AND EC MODEL INITIALIZATIONS AND FORECAST
TRENDS THROUGH 84 HOURS. THE GFS WITH SOME MODIFICATION WILL BE USED
FOR AFTERNOON FORECAST PACKAGES.

.ANALYSIS/FORECAST...

LOW CENTER OVER WESTERN BRISTOL BAY MOVES INLAND ALONG THE NORTHERN
COAST LATE TONIGHT. A DEVELOPING LOW SOUTH OF THE EASTERN ALEUTIANS
DEEPENS TO 966 MB JUST SOUTH OF KODIAK ISLAND THIS EVENING. THIS LOW
THEN MOVES INTO SOUTHERN COOK INLET BY MID TUE MORNING. LOW CENTER
THEN MOVES INLAND OVER THE NORTH KUSKOKWIM VALLEY TUE EVENING. A LOW
PRESSURE TROUGH CONTINUES OVER WESTERN ALASKA THROUGH THU. A
DEVELOPING WITH TROPICAL ORIGINS DEEPENS AS IT MOVES SOUTH OF THE
ALEUTIANS AND ENDS UP NEAR KODIAK ISLAND IN THE 970S THU MORNING.
MODELS HAVE DIFFERED ON EARLIER RUNS WITH THIS SYSTEM. MORE CHANGES
IN TRACK AND INTENSITY LIKELY UNTIL THINGS SETTLE DOWN.

.EAST...PRESSURE GRADIENTS ACROSS SOUTHCENTRAL WILL INCREASE SOME
THIS AFTERNOON AS WEAKENING FRONT ASSOCIATED WITH BRISTOL BAY CENTER
MOVES EAST/NORTH. MAIN PRESSURE/MOISTURE SURGE COMES AS SECONDARY
CENTER MOVES INTO SOUTHERN COOK INLET TONIGHT/TUE MORNING. EXPECT
HIGH WIND WARNINGS CONDITIONS LIKELY TONIGHT THROUGH TUE ZONES 101
AND 125 WITH NUMEROUS STRONG WIND HEADLINES IN SOUTHCENTRAL PUBLIC
ZONES AND GALES/STORMS IN COASTAL MARINE AREAS. EXPECT WARNING LEVEL
WINDS WILL DIMINISH OVER SOUTHCENTRAL BY TUE EVENING AS LOW CENTER
MOVES NORTH OF THE AK RANGE. WARM ADVECTION WITH CENTER LIKELY TO
BRING RAIN AND SNOW TO SOUTHCENTRAL...WITH SNOW AT HIGHER ELEVATIONS.
ZONE 131 THOMPSON PASS MAY SEE BLIZZARD CONDITIONS DEVELOP LATER
TONIGHT WITH ONSET OF SE FLOW IN THE MID LEVELS AND MOISTURE SURGE
ASSOCIATED WITH ADVANCING FRONT. EXPECT BLIZZARD CONDITIONS SHOULD
DIMINISH TUE AFTERNOON AS SNOW MIXES WITH RAIN.

.WEST...LOW OVER WESTERN BRISTOL BAY WILL DRIFT INLAND TONIGHT. WARM
AIR SHOULD KEEP PRECIPITATION MAINLY RAIN OVER BRISTOL BAY TONIGHT.
WARM AIR OVERRUNNING COLD AIR MAY PRODUCE SOME POCKETS OF LIGHT
FREEZING RAIN OVER THE KUSKOKWIM VALLEY TONIGHT AND TUE...MAY SEE
BRIEF PERIOD OF FREEZING RAIN OVER THE DELTA THIS EVENING UNTIL COLD
AIR INTRUSION. STRONG NW WINDS SET UP OVER THE EAST ALEUTIANS AND THE
AK PEN TONIGHT AND CONTINUES THROUGH TUE EVENING. COLD ADVECTION INTO
SW AK AND TROUGH HOLD OVER THE MAINLAND WILL PRODUCE UNSETTLED
WEATHER WITH SNOW/SNOW SHOWERS THROUGH WED.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...HIGH WIND WARNINGS ZONES 101 AND 125. BLIZZARD WARNING ZONE
131.
MARINE...STORM 120, 130, 132
         GALE 121, 125, 129, 138, 140
FIRE WEATHER...NONE.

RMC OCT 07