Small Craft Advisory 472, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
130 PM ADT WED JUN 8 2005

.DISCUSSION...

.ANALYSIS...THE DOMINANT FEATURE CONTINUES TO BE A MATURE VERTICALLY
STACKED LOW CENTERED OVER THE EASTERN ALEUTIANS. LARGE CYCLONIC
CIRCULATION AROUND THE LOW IS AFFECTING ALL OF THE AFC AOR. THERE
IS A WEAK SURFACE TROUGH EXTENDING FROM THIS LOW INTO THE GULF.
AREAS OF RAIN AND SHOWERS ARE WIDESPREAD FROM THE EASTERN ALEUTIANS
TO KODIAK ISLAND. MOIST SOUTHEAST FLOW ACROSS THE SOUTHERN MAINLAND
IS RESULTING IN SOME RAIN ALONG THE COAST AND A FEW SHOWERS INLAND.
ABUNDANT CLOUDINESS MAINTAINING FAIRLY STABLE ATMOSPHERE. A LOOK AT
VISIBLE SATELLITE IMAGERY SHOWS ONLY BREAKS IN CLOUDS ARE OVER COPPER
RIVER BASIN AND THE KILBUCK MOUNTAINS TO THE KUSKOKWIM DELTA. THERE
IS SOME CU DEVELOPMENT THAT MAY PRODUCE A FEW ISOLATED SHOWERS LATER
THIS AFTERNOON. RIDGE  ALONG THE NORTH GULF COAST IS PRODUCING GUSTY
EAST WINDS AND DOWNSLOPING IN THE USUAL AREAS. A DEVELOPING SURFACE
LOW IS LOCATED SOUTH OF AKPENN NEAR 51N 156W. WATER VAPOR SHOWS A
STRONG MID LEVEL SHORT-WAVE TRACKING EASTWARD ALONG THE BOTTOM OF
THE UPPER TROUGH TOWARD THIS SURFACE LOW. THIS SHOULD LEAD TO SOME
DEEPENING OF THE SURFACE LOW  AS IT IS FORCED NORTHWARD INTO THE
GULF OF ALASKA.

.MODEL ANALYSIS...GFS/UKMET/NAM ARE IN GOOD AGREEMENT THROUGH 48
HOURS AND THEN THE ETA BEGINS TO DIVERGE WITH POSITION OF LOW IN THE
GULF. HOWEVER..THE DIFFERENCES DO NOT HAVE A SIGNIFICANT IMPACT ON
THE RESULTANT SENSIBLE WEATHER. PREFER THE GFS/UKMET SOLUTION OF
KEEPING THE LOW NEARLY STATIONARY OVER THE GULF. WITH RESPECT TO THE
CURRENT LOW OVER THE EASTERN ALEUTIANS...THE LAST FEW MODEL RUNS
HAVE BEEN INDICATING THAT AS NEW LOW DEVELOPS AND MOVES INTO GULF
THE ALEUTIAN LOW WILL DISSIPATE AND THE MAIN UPPER CIRCULATION WILL
SHIFT TO THE GULF. THE MODELS HAVE BEEN TOO FAST WITH THIS PROCESS.
THEREFORE...FEEL THE EASTERN ALEUTIAN LOW WILL LINGER A LITTLE
LONGER OVER EASTERN ALEUTIANS/SOUTHERN AKPENN THAN MODELS INDICATE.

.SOUTHERN MAINLAND FORECASTS...DEVELOPING LOW WILL MOVE INTO GULF
WITH A SURFACE PRESSURE AROUND 990 MB LATE TONIGHT. THIS WILL PUSH
SURFACE RIDGE ALONG NORTH GULF COAST INLAND AND SPREAD RAIN ALONG
THE GULF COAST ON THURSDAY. EVEN WITHOUT COASTAL RIDGE STRONG
SYNOPTIC EASTERLY FLOW WILL MAINTAIN DOWNSLOPE DRYING IN THE USUAL
AREAS. FOR INLAND AREAS AND ALL OF SOUTHWEST ALASKA EXPECT ISOLATED
TO SCATTERED SHOWERS DUE TO WEAK UPPER LEVEL DISTURBANCES MOVING
ACROSS THE REGION IN BROAD EAST TO SOUTHEAST FLOW. EXTENSIVE CLOUD
COVER WILL PREVENT ANY SIGNIFICANT DESTABILIZATION OF ATMOSPHERE.
AS LOW WEAKENS ON FRIDAY AND SATURDAY EXPECT SOME BREAKS IN THE
CLOUDS AND AN INCREASE IN AFTERNOON/EVENING CONVECTION.

.BERING SEA REGION FORECASTS...AS INDICATED ABOVE LOW OVER EASTERN
ALEUTIANS WILL LIKELY LINGER A LITTLE LONGER THAN MODELS
INDICATE...LIKELY THROUGH THURSDAY BEFORE DISSIPATING THURSDAY NIGHT.
SO EXPECT CONTINUED SHOWERS FOR THE EASTERN ALEUTIANS/SOUTHERN AKPENN
TONIGHT AND THURSDAY DIMINISHING TO SCATTERED SHOWERS THURSDAY NIGHT.
A RIDGE OF HIGH PRESSURE WILL BUILD OVER THE WESTERN BERING SEA
THURSDAY AND SLIDE EASTWARD FRIDAY AND SATURDAY. THIS WILL RESULT
IN BROAD NORTHWEST FLOW ACROSS THE REGION WITH AREAS OF LOW CLOUDS
AND FOG. THE NEXT LOW WILL TRACK OUT OF RUSSIA THURSDAY NIGHT TO THE
WESTERN BERING SATURDAY PUSHING A FRONTAL BOUNDARY ACROSS THE WESTERN
ALEUTIANS. AT THIS POINT IT LOOKS LIKE WINDS WILL PEAK AT SMALL CRAFT
AS THIS FRONT MOVES ACROSS.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALES 2B.
FIRE WEATHER...RED FLAG WARNING ZONE 111 THIS AFTERNOON AND EVENING.

SEB JUN 05