Snow Advisory 18, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
400 AM ADT MON MAY 28 2007

.ANALYSIS AND UPPER LEVELS...
FAIRLY QUIET WEATHER IS PRESENT OVER THE FORECAST AREA THIS
MORNING...WITH WEAK UPPER LEVEL SOUTHEAST FLOW. HOWEVER...TWO LARGE
AREAS OF LOW PRESSURE ARE APPROACHING THE FORECAST AREA TODAY. ONE
LOW SOUTHWEST OF SHEMYA IS ALREADY SENDING A FRONT OUT AHEAD OF IT
WITH GALE FORCE WINDS AND RAIN TO THE WESTERN ALEUTIANS TODAY.
ANOTHER LARGE LOW IS MOVING NORTH INTO THE SOUTHERN GULF OF ALASKA
TODAY. BOTH OF THESE LOWS WILL BE THE BIG WEATHER PLAYERS FOR THE
FORECAST AREA OVER THE NEXT SEVERAL DAYS. THE ALEUTIAN LOW WILL
SLOWLY PROGRESS EAST ALONG OR JUST SOUTH OF THE CHAIN THROUGH
FRIDAY. THE GULF LOW WILL MOVE NORTH AND GRADUALLY DISSIPATE NEAR
KODIAK...BUT IT WILL BRING RAIN TO ESPECIALLY COASTAL SOUTHCENTRAL
AND GALE FORCE WINDS OVER MARINE AREAS OVER THE NEXT FEW DAYS.

.MODEL DISCUSSION...
MODELS ARE STILL IN PRETTY GOOD AGREEMENT. THERE IS SOME MODEL
DISAGREEMENT AND INCONSISTENCY LATE WEDNESDAY INTO THURSDAY AS TO
WHETHER THE LOW SOUTH OF CENTRAL/EASTERN ALEUTIANS IS ONE
CONSOLIDATED LOW OR TWO LOW DIFFERENT LOWS. THERE IS ALSO SOME MODEL
DISAGREEMENT ON HOW FAST THE GULF LOW DISSIPATES AS IT APPROACHES
KODIAK WEDNESDAY. BOTH OF THESE ARE FAIRLY MINOR ISSUES.

.SHORT TERM FORECAST...
SOUTHCENTRAL...
STILL SOME WEAK ENERGY ASSOCIATED WITH A DYING LOW OVER THE NORTHERN
GULF OF ALASKA. THIS COUPLED WITH FAIRLY MOIST SOUTHEAST FLOW WILL
CONTINUE TO BRING LIGHT RAIN AND HIGH ELEVATION SNOW TO IMMEDIATE
COASTAL SOUTHCENTRAL TODAY...AS WELL AS ALONG THE MOUNTAINS INLAND.
HOWEVER...THE LOWER ELEVATIONS OF SOUTHCENTRAL SHOULD SEE A
RESPECTABLE DAY TODAY WITH SOME SUNSHINE ESPECIALLY TOWARD LATE
AFTERNOON. THE ENERGY OVER THE GULF WILL CROSS THE ALASKA RANGE
LATER THIS AFTERNOON AS HIGH PRESSURE STRENGTHENS OVER SOUTHCENTRAL.
THIS WILL LEAD TO A QUIET NIGHT OVER SOUTHCENTRAL THOUGH THERE MAY
BE SOME FOG. HOWEVER...THE STRONG LOW PROGRESSING NORTH INTO THE
GULF WILL BEGIN TO BRING RAIN TO KODIAK TONIGHT...AND TO COASTAL
SOUTHCENTRAL TUESDAY. MOIST SOUTHEAST FLOW WILL PERSIST EVEN AFTER
THE LOW DISSIPATES NEAR KODIAK ON WEDNESDAY. LOWER ELEVATIONS INLAND
ARE NOT EXPECTED TO SEE MUCH RAIN TUESDAY AND WEDNESDAY...ALTHOUGH
KODIAK AND COASTAL SOUTHCENTRAL WILL SEE COPIOUS RAINFALL.

SOUTHWEST MAINLAND...
FAIRLY WEAK AND FAIRLY MOIST EAST TO SOUTHEAST FLOW WILL AFFECT THE
SOUTHWEST MAINLAND THROUGH WEDNESDAY. EXPECT GENERALLY MOSTLY CLOUDY
SKIES WITH FAIRLY SMALL RAIN CHANCES. THE LOW NEAR KODIAK COULD
AFFECT EASTERN PORTIONS OF BRISTOL BAY AND AREAS NEAR THE ALEUTIAN
RANGE WITH SOME INCREASED WINDS AND RAIN CHANCES WEDNESDAY.

BERING SEA/ALEUTIANS...
WET AND WINDY WEATHER WILL BE THE RULE THROUGH WEDNESDAY FOR THE
ALEUTIANS AND BERING AS A STRONG WIDE REACHING LOW PRESSURE AND
ASSOCIATED FRONT PROGRESS SLOWLY EASTWARD ALONG THE SOUTH SIDE OF
THE CHAIN.

.LONG TERM FORECAST...
UNSETTLED WEATHER TO PERSIST THURSDAY ONWARD. ALL MODELS INDICATE
LOW PRESSURE SOMEWHERE JUST SOUTH OF THE ALASKA PENINSULA. THIS
MEANS CONTINUE MOIST ONSHORE FLOW TO SOUTHCENTRAL...AND OF COURSE
PRECIPITATION AS WELL NEAR THE LOW FROM THE EASTERN ALEUTIANS TO THE
ALASKA PENINSULA. THE CENTRAL AND WESTERN ALEUTIANS/BERING MAY DRY
OUT A BIT IN THE EXTENDED.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE WARNING ZONES 120 130 132 176 350
FIRE WEATHER...NONE

FOISY MAY 07