Small Craft Advisory 667, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 PM AKDT THU SEP 4 2008

.MODEL DISCUSSION...MODELS IN GENERAL ARE IN FAIR AGREEMENT. GRIDS
WILL BE BLENDED TOWARD 12Z GFS. THIS WILL RESULT IN SIMILAR TIMING
BUT A MORE INTENSE SOLUTION SAT.

.UPPER LEVELS...UPPER TROUGH EXTENDS FROM OVER MAINLAND ALASKA SW TI
NEAR 35N 170W THIS AFTERNOON. LOW CENTER NEAR THE BASE OF THE TROUGH
DIGS EAST TO ALONG 165W FRI EVENING. CENTER THEN INTENSIFIES AS IT
MOVES TO OVER BRISTOL BAY EARLY SUN. IN RESPONSE...RIDGING BUILDS
OVER THE GULF OF ALASKA AND THE MAINLAND. WARMER AIR MOVES OVER THE
MAINLAND AS THE STORM TRACK SHIFTS NORTH WITH ONSET OF SOUTHERLY JET.

A PIECE OF THE ENERGY ASSOCIATED WITH THE BRISTOL BAY CENTER FLATTENS
THE RIDGE SOME AS IT MOVES ACROSS THE MAINLAND SUN NIGHT/MON. BRISTOL
BAY CENTER RETROGRADES TO THE EASTERN ALEUTIANS MON.

...SURFACE FORECAST...
.EAST...WEAK PRESSURE FIELD AND TROUGH ALOFT WILL HOLD A CHANGE OF
RAIN OR SHOWERS OVER MUCH OF THE EAST THROUGH EARLY FRIDAY. HIGH
PRESSURE BUILDS OVER THE MAINLAND AND GULF FRI AND RETREATS TO THE
EASTERN GULF SAT NIGHT. EXPECT WILL SEE STRATUS AND FOG WITH PASSAGE
OF RIDGE. DEVELOPING LOW CENTER OVER THE NE PACIFIC LOOKS TO BE A
FAIRLY IMPRESSIVE STORM. DIGGING UPPER TROUGH AND FAVORABLE JET
POSITION SUPPORTS MODEL INTENSIFICATION TREND ON THIS CENTER. CENTER
MOVES TO NEAR PORT HEIDEN FRI SAT NIGHT. CENTER LIKELY TO WEAKEN
SIGNIFICANTLY AS IT TRACKS TO MARINE AREA 180 SUN AFTERNOON. EXPECT
VERY WINDY CONDITIONS OVER THE GULF OF ALASKA SAT AND SOUTHCENTRAL
SUN NIGHT. RAIN WILL BE PREDOMINATELY ALONG THE COAST AND SE
EXPOSURES OF THE GULF AND SOUTHCENTRAL ALASKA. DOWNSLOPE CONDITIONS
WILL KEEP PRECIPITATION VALUES TO A MINIMUM INLAND.

.WEST...LOW OVER THE EASTERN BERING SEA/SW ALASKA WILL RETROGRADE
WEST UNDER UPPER TROUGH. DEVELOPING NE PACIFIC CENTER MOVES TO NEAR
PORT HEIDEN FRI THEN WEAKENS ALONG THE SW COAST SUN. EXPECT CLOUDS
WITH AREAS OF RAIN/SHOWERS AND SOME FOG LIKELY TO HOLD OVER SW
ALASKA/EASTERN BERING SEA WITH WEAK PRESSURE GRADIENTS INTO FRI. MAY
SEE BRIEF BREAKS OVER SW ALASKA WITH THE ONSET OF OFFSHORE FLOW IN
ADVANCE OF DEVELOPING LOW CENTER SAT. WINDS IN ADVANCE OF LOW CENTER
LIKELY TO BE GALE TO NEAR STORM FORCE AS IT APPROACHES THE ALASKA
PENINSULA SAT. WINDS WITH STRATUS AND FOG LIKELY OVER THE CENTRAL
BERING SEA WITH WEAK RIDGING. TROUGH OVER THE WESTERN BERING SEA WILL
PRODUCE SOME RAIN A BRISK SOUTHERLY WINDS THROUGH EARLY SAT.

.LONG TERM FORECAST...FEW CHANGES MADE IN THE WEST. WENT WITH GREATER
BLEND TOWARD THE 12Z GFS IN THE EAST.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...NONE.
FIRE WEATHER...NONE.

RMC SEP 08