Blizzard and Flood in Alaska, January 13 to 19, 2009

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 PM AKST TUE JAN 13 2009

.MODEL DISCUSSION...
MODELS ARE IN GENERALLY GOOD AGREEMENT THROUGH THURSDAY NIGHT THOUGH
THERE STILL TIMING DIFFERENCES OF THE SHORTWAVES MOVING INTO THE GULF
AND SOUTHCENTRAL ALASKA.

.ANALYSIS AND UPPER LEVELS...
AN UPPER TROUGH OVER THE BERING SEA AND AN UPPER RIDGE ALONG THE WEST
COAST OF CANADA AND OVER SOUTHEAST ALASKA CONTINUES TO STEER STRONG
SOUTHERLY FLOW OVER MAINLAND ALASKA.

A 964 MB LOW SOUTH OF THE CENTRAL ALEUTIANS WITH A WEATHER FRONT OVER
THE EASTERN ALEUTIANS, THE ALASKA PENINSULA AND THE GULF OF ALASKA
HAD MOVED SNOW INTO BRISTOL BAY, EASTERN KUSKOKWIM VALLEY, THE
SUSITNA VALLEY AND MOST OF SOUTHCENTRAL ALASKA THIS MORNING. SNOW IS
EXPECTED TO CHANGE TO RAIN ALONG THE CENTRAL GULF COAST AND PARTS OF
BRISTOL BAY THIS EVENING.

.SHORT TERM FORECAST...
ALEUTIANS AND BERING SEA...THE LOW SOUTH OF THE CHAIN WILL TURN
NORTHEAST AND DISSIPATE NEAR DUTCH HARBOR THURSDAY. ANOTHER 970 MB
LOW WILL DEVELOP SOUTH OF THE EASTERN ALEUTIANS THURSDAY. THE AREA OF
WARM AIR ON THE EAST SIDE OF THE LOW SPREAD INTO THE EASTERN BERING
THROUGH TONIGHT. A STRONG NORTHERN WINDS OVER THE CENTRAL AND WESTERN
BERING WILL PERSIST THROUGH THURSDAY NIGHT. A STATIONARY FRONT WILL
DEVELOP ALONG 170W LONGITUDE BY WEDNESDAY NIGHT AND REMAIN THROUGH
THURSDAY.

SOUTHWEST ALASKA....STRONG SOUTHERLY FLOW WILL CONTINUE TO MOVE WARM
MOIST AIR INTO THE AREA THROUGH THE PERIOD. AREAS OF SNOW OVER
BRISTOL BAY AND EASTERN KUSKOKWIM VALLEY WILL SPREAD INTO REST OF
SOUTHWEST ALASKA BY LATE TONIGHT. THE SNOW WILL CHANGE TO RAIN WITH A
FEW AREAS OF FREEZING RAIN OVER THE BRISTOL BAY ZONE TONIGHT AND OVER
MOST OF THE KUSKOKWIM VALLEY AND INLAND PORTIONS OF THE KUSKOKWIM
DELTA WEDNESDAY. NORTH WINDS ALONG THE KUSKOKWIM DELTA COAST WILL
INCREASE TONIGHT AND WEDNESDAY WITH POSSIBLE BLIZZARD CONDITION
DEVELOPING ALONG THE COAST WEDNESDAY. WINDS WILL DIMINISH WEDNESDAY
EVENING.

SOUTHCENTRAL AK...
A STRONG SOUTHERLY FLOW WILL CONTINUE TO PUSH WARMER, MOISTER AIR
OVER THE GULF OF ALASKA AND SOUTHCENTRAL ALASKA THROUGH THURSDAY
NIGHT. SNOW WILL BEGIN TO CHANGE TO RAIN FROM THE SOUTH AS
TEMPERATURES CONTINUE TO WARM THROUGH TONIGHT AND WEDNESDAY. THE
WESTERN SUSITNA VALLEY AND NORTHERN COPPER RIVER BASIN IS EXPECTED TO
GET THE MOST SNOW DUE TO UPSLOPE EFFECTS. ISOLATED AREAS OF FREEZING
RAIN MAY DEVELOP AS THE THE PRECIPITATION TRANSITION FROM SNOW TO
RAIN. LOCAL GAP WINDS WILL DEVELOP THROUGH THE KENAI AND CHUGACH
MOUNTAINS AS THE PRESSURE GRADIENT INCREASES OVER THE SOUTHCENTRAL
REGION OVER THE NEXT FEW DAYS.

.LONG TERM FORECAST...
VERY LITTLE CHANGE IS EXPECTED IN THE OVERALL PATTERN. THE LOW
PRESSURE SYSTEM NEAR THE EASTERN ALEUTIANS WILL WEAKEN AND DIG A
TROUGH OVER WESTERN ALASKA TOWARD THE END OF THE WEEK. THIS WILL MOVE
THE CORE OF STRONG SOUTHERLY FLOW FROM THE CENTRAL GULF INTO THE
EASTERN GULF BY THE WEEKEND.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...HIGH WIND WATCH FOR ZONES 101 AND 125 ALONG TURNAGAIN ARM.
MARINE...STORM...120
         GALE...125, 130, 132, 150, 170, 172, 175, 176,179, 180, 185
FIRE WEATHER...NONE.

NM JAN 09