Small Craft Advisory 669, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 PM ADT FRI AUG 17 2007

.MODEL DISCUSSION...
MODELS IN OK AGREEMENT. NAM ATTEMPTS GREATER RESOLUTION OF LOWS
IN BERING SEA THAN ACTUALLY EXISTS. GFS PREFERRED DUE TO IT SUPERIOR
HANDLING OF BERING SEA LOWS.

.UPPER LEVELS...
UPPER LEVEL LOW CENTERED OVER NORTHWESTERN BERING SEA SHIFTS
SOUTHWARD TO WESTERN ALEUTIANS BY MONDAY MORNING.
UPPER LEVEL LOW OVER CENTRAL ALEUTIANS AND UPPER LEVEL LOW OVER
KODIAK ISLAND MERGE OVER ALASKA PENINSULA SATURDAY AFTERNOON.
COMBINED LOW GRADUALLY WEAKENS AND DRIFTS EASTWARD.

.SURFACE ANALYSIS...
WEAK THERMAL TROUGH HOLDS OVER SOUTHERN INTERIOR ALASKA.
WEAK RIDGE OF HIGH PRESSURE ALONG GULF COAST HOLDS THROUGH SATURDAY
THEN RECEDES SOUTHEASTWARD SATURDAY NIGHT AND SUNDAY.
994 MB LOW SOUTH OF ALASKA PENINSULA DISSIPATES OVER WESTERN KODIAK
ISLAND SAT EVENING.
983 MB LOW NORTHWEST OF ADAK REPOSITIONS ITSELF TO BE NEAR COLD BAY
SUNDAY AFTERNOON THEN WEAKENS AND DRIFTS WESTWARD BENEATH UPPER LEVEL
FEATURE.
SMALL 998 MB LOW WILL MOVE OVER WESTERN ALEUTIANS SUN AFTERNOON.

.SHORT TERM FORECAST...
WELL DEFINED BAND OF SHOWERS EXTENDS FROM MIDDLETON ISLAND ACROSS
KENAI PENINSULA AND COOK INLET. MODERATE RAIN SHOWERS REPORTED AT
SEWARD. GENERAL MOVEMENT IS SLOWLY NORTHWARD. UPDATED KENAI PENINSULA
AND ANCHORAGE BOWL ZONES ACCORDINGLY.
AIRMASS OVER NORTHERN SUSITNA AND COPPER RIVER VALLEYS IS SLIGHTLY
UNSTABLE. SLIGHT CHANCE OF CONVECTIVE ACTIVITY TOMORROW.
REMNANTS OF OLD FRONT HANGING IN ALONG KUSKOKWIM DELTA AND BERING
COASTS BUT EXPECTED TO MAKE LITTLE PROGRESS INLAND.
POTENTIAL FOR GALE FORCE WINDS TOMORROW AROUND KODIAK ISLAND AS
GRADIENT BETWEEN RIDGE ALONG GULF COAST AND LOW PRESSURE MOVING TO
THE WESTERN ISLAND TIGHTENS.
ALSO GALE FORCE WINDS OVER CENTRAL ALEUTIANS TONIGHT ON BACKSIDE OF
MAIN ALEUTIAN LOW.

.LONG TERM FORECAST...
GENERALLY MILD PATTERN PROGGED FOR UPCOMING WEEK.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALES 130 172.
FIRE WEATHER...NONE.

ASB AUG 07