Areal Flood Advisory 3, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
200 PM AKDT SUN MAY 13 2012

.MODEL DISCUSSION...MODELS ARE IN FAIR AGREEMENT THROUGH THE NEXT 48
HRS. THE ECMWF MODEL OVERALL HANDLES THE LOW OVER THE NORTHERN GULF
AND COMPLEX OUT WEST THE BEST AND WILL BE USED FOR THE FORECAST
PACKAGE.

.ANALYSIS AND UPPER LEVELS...

.500 MB...A COLD LOW NEAR KODIAK MOVES EAST TO OVER SOUTHEAST ALASKA
TUE EVENING. A HIGH AMPLITUDE RIDGE OVER THE EASTERN BERING SEA MOVES

TO OVER THE WESTERN HALF OF THE MAINLAND TUESDAY. A COLD LOW OVER THE
KAMCHATKA PENINSULA INTENSIFIES AS IT DROPS SOUTH OF THE WESTERN
ALEUTIANS TUESDAY.

.SURFACE...

THE SNOWFALL OVER NORTHERN KODIAK ISLAND WILL CONTINUE TO DIMINISH
THROUGH THIS AFTERNOON AS THE SURFACE LOW WEAKENS. A SECONDARY LOW
DEVELOPS SOUTHEAST OF KODIAK THIS AFTERNOON AND MOVES TO THE NORTH
CENTRAL GULF OF ALASKA TONIGHT. THIS LOW WILL LIKELY BRING GALES TO
THE GULF AND POTENTIALLY STRONG WINDS TO THE NORTH GULF COAST
TONIGHT. THE HIGH PRESSURE RIDGE OVER THE EASTERN BERING SEA
PROGRESSES EAST TONIGHT TO OVER THE GULF AND CENTRAL MAINLAND BY TUE.
THE LOW CENTER SOUTH OF THE WESTERN ALEUTIANS MOVES TO THE NORTHEAST
BERING SEA TUE AND WEAKENS. A SECONDARY CENTER NEAR THE KAMCHATKA
PENINSULA TODAY MOVES SOUTH OF THE CENTRAL ALEUTIANS TUE.

.SHORT TERM FORECAST...

.SOUTHCENTRAL...SHOWERS WILL CONTINUE ACROSS MUCH OF THE GULF COAST
THROUGH TONIGHT AS THE UPPER TROUGH AND SURFACE CENTER PROCESS EAST.
SHOWERS ARE EXPECTED ACROSS MUCH OF THE GULF COAST. SHOWERS WILL BE
MIXED AT TIMES AS TEMPERATURES CONTINUE TO COOL ALOFT THROUGH MON.
COOLING TEMPS ALOFT MAY ALSO TRIGGER AFTERNOON AND EVENING
THUNDERSTORMS OVER THE COPPER RIVER BASIN AND THE TALKEETNA MOUNTAINS
TODAY AND MON. GALES ARE EXPECTED OVER THE NORTH GULF OF ALASKA
TONIGHT WITH THE DEVELOPING SURFACE LOW. A WEAK BARRIER JET WILL ALSO
BRING BRISK EASTERLY WINDS TO THE NORTH GULF GULF TONIGHT. DRIER AND
WARMER WEATHER IS ON THE WAY WITH THE RIDGE TUE AND WED.

BEARING SEA/ALEUTIANS...PERIODS OF GALES AND WARMING CONDITIONS ARE
EXPECTED OVER THE REGION OVER THE NEXT DAY OR SO AS A SERIES OF LOWS
IMPACT THE AREA. PRECIPITATION TYPE SHOULD CHANGE FROM MIXED TO
GENERALLY RAIN OR SHOWERS.

FOR SW AK...MIXED SHOWERS ARE EXPECTED INLAND AREAS AND BRISTOL BAY
TONIGHT...AND MAINLY INLAND ON MON. CONDITIONS OVER ALL WILL
STABILIZE AS HIGH PRESSURE BUILDS IN FROM THE WEST MON AND TUE.
EXPECT STRATUS AND FOG TO AFFECT THE COASTS WITH THE BUILDING RIDGE
AND IMPACT AVIATION OPERATIONS MON AND TUE.

.LONG TERM FORECAST...
THE WEST WILL CONTINUE TO HAVE RAIN UNTIL A RIDGE BUILDS IN AT THE
END OF THE WEEK. SW AK WILL REMAIN DRY UNTIL SOME SHOWERS ARRIVE ON
FRI. SE OF THE AK RANGE WILL REMAIN DRY UNTIL AFTERNOON AND EVENING
MOUNTAIN CONVECTION RETURN AT WEEKS END AS THE THERMAL TROUGH
REDEVELOPS ALONG THE AK RANGE.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...FLOOD WATCH 155.
MARINE...GALES 120 172 175 351 413
FIRE WEATHER...NONE.

RMC MAY 12