FXAK68 PAFC 092357
AFDAFC
AREA FORECAST DISCUSSION 
SOUTHCENTRAL AND SOUTHWEST ALASKA
400 PM AKDT SAT MAY 9 2009
.ANALYSIS AND UPPER LEVELS...THE UPPER LEVEL PATTERN HAS A COLD
TROUGH EXTENDING OUT OF THE ARCTIC OCEAN...DOWN THE ALCAN
BORDER...AND INTO A CUT-OFF LOW OVER THE GULF OF ALASKA. THE SURFACE
REFLECTION OF THIS IS VISIBLE IN THE WEAK LOW IN THE GULF THAT IS
EASILY SEEN ON SATELLITE. 
A LARGE HIGH IS OVER THE EASTERN BERING SEA AND SOUTHWEST ALASKA.
THIS HIGH WILL REMAIN FAIRLY STATIONARY THE NEXT FEW DAYS WITH JUST A
SMALL MOVEMENT OF THE CENTER TO THE NORTH ON MONDAY. WHILE TO SURFACE
RIDGE DOES NOT MOVE MUCH THE UPPER RIDGE WILL MOVE TO AND STRENGTHEN
OVER SOUTHWEST ALASKA MONDAY. THIS WILL BRING WARMER TEMPERATURES TO
SOUTHWEST AND SOUTH CENTRAL ALASKA BY MONDAY. 
.SHORT TERM FORECAST...HIGH PRESSURE OVER THE BERING SEA AND BRISTOL
BAY THIS TIME OF YEAR USUALLY MEANS LOW STRATUS AND FOG...AND THIS IS
NO EXCEPTION. EXPECT FOG TO PERSIST NEAR THE COAST OF SOUTHWEST
ALASKA AND THE ALASKA PENINSULA THROUGH THE WEEKEND. THE SITUATION
MAY IMPROVE IN SOUTHWEST ALASKA AFTER THAT AS THE FLOW BECOMES MORE
NORTHERLY AND OFF SHORE. 
MOISTURE AND A LITTLE INSTABILITY OVER THE COPPER RIVER BASIN WILL
KEEP THINGS CLOUDY WITH A FEW SHOWERS IN THAT AREA OVERNIGHT BEFORE
THE TIGHTENING GRADIENT INCREASES NORTHERLY WINDS TEMPERATURES WHILE
DROPPING RELATIVE HUMIDITY VALUES SUNDAY. THIS COMBINATION WILL
NECESSITATE A FIRE WEATHER WATCH IN ZONE 141 FOR LATE SUNDAY
AFTERNOON AND EVENING.
WITH THE EXCEPTION OF THE LITTLE BIT OF INSTABILITY IN THE COPPER
RIVER BASIN THE ATMOSPHERE IS RELATIVELY STABLE AND WILL NOT SUPPORT
MUCH CONVECTIVE ACTIVITY. 
.MODEL DISCUSSION...MODELS REMAIN IN GOOD AGREEMENT INTO THE MIDDLE
OF NEXT WEEK WITH NO MAJOR CONCERNS WITH ANY OF THEM AT THIS TIME.
.LONG TERM FORECAST...THE OMEGA BLOCK PATTERN THAT IS SETTING UP OVER
THE AREA LOOKS TO REMAIN IN PLACE THROUGH AT LEAST THE MIDDLE OF NEXT
WEEK. THE BIGGEST FORECAST CHALLENGE WILL BE TO DETECT ANY SHORT
WAVES THAT MIGHT DEVELOP MOVE DOWN OVER THE AREA IN THAT NORTHERLY
FLOW.
.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...FLOOD WARNINGS 155.
MARINE...GALE 176.
FIRE WEATHER...FIRE WEATHER WATCH 141.
MAY 09