Small Craft Advisory 92, NWS Fairbanks, AK

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
103 PM AKDT SAT SEP 3 2011

.DISCUSSION...
THE MAJOR FORECAST ISSUE TODAY WILL BE INCREASING WINDS AND
SEAS OVER THE WEST COAST MARINE AREAS...AND INCREASING
WINDS OVER NEARBY LAND AREAS.

CURRENT SURFACE AND UPPER PROGS TODAY AGREE WELL OUT THROUGH
00Z WED AND HAVE GOOD CONTINUITY WITH THE CORRESPONDING MODEL
RUNS AVAILABLE YESTERDAY AS WELL AS THE IMMEDIATELY PRECEDING
RUNS. THUS FORECAST CONFIDENCE IN THIS SCENARIO IS HIGH.

18Z SYNOPTIC PLOT INDICATES A SURFACE LOW AROUND 1003 MB OVER
THE SOUTHERN PART OF THE KAMCHATKA PENINSULA...AND THE CURRENT
RUNS OF THE GFS/NAM/EUROPEAN MODELS HAVE PICKED UP THIS FEATURE.
THIS SYSTEM WILL MOVE RAPIDLY EASTWARD WHILE DEEPENING THROUGH
00Z MON. FORECAST POSITION FOR 00Z MON WILL BE NEAR DUTCH HARBOR
WITH CENTRAL PRESSURE 980-982 MB. SUBSTANTIAL FURTHER DEEPENING OF
THE LOW IS EXPECTED THROUGH 00Z TUE AS THE LOW MOVES INTO THE
NORTHERN GULF OF ALASKA. THE LOW IS EXPECTED TO BE AROUND 200
MILES SOUTHEAST OF KODIAK ISLAND BY 00Z TUE WITH CENTRAL PRESSURE
955-960 MB.

ALOFT...WEAK UPPER LOW DEVELOPING TODAY WEST OF NUNIVAK ISLAND
WILL MOVE SOUTHEAST AND DEEPEN RAPIDLY...REINFORCED BY A SHORT
WAVE IMPULSE MOVING RAPIDLY EASTWARD ACROSS THE NORTHERN PACIFIC.
500 MB HEIGHTS IN THE UPPER LOW DROPPING TO TYPICAL MID-WINTER
VALUES BY 12Z MON AS THE CENTER DIVES SOUTHEASTWARD TO ABOUT 500
MILES SOUTH SOUTHWEST OF KODIAK. LONG WAVE TROUGH POSITION WILL BE
MAINTAINED OVER THE ALASKA MAINLAND WELL INTO NEXT WEEK.

COASTAL HAZARD POTENTIAL DAYS 3 AND 4...
NORTHERLY GALES TO 40-50 MPH EXPECTED TO BEGIN OVER
PKZ210-PKZ220-AKZ213 EARLY MON. SEAS TO 11-13 FEET DEVELOPING IN
PKZ210...AND IN PKZ220 AND THE BERING STRAIT AREA...BY MON
AFTERNOON. WAVES MAY DECREASE SOME AS THEY BREAK ONSHORE ALONG
THE NORTH SHORE OF ST LAWRENCE ISLAND...BUT WILL STILL BE HIGH.
SIGNIFICANT BEACH EROSION IS LIKELY IN AREAS ALONG THE NORTH
FACING SHORE OF ST LAWRENCE ISLAND...INCLUDING THE VILLAGE OF
SAVOONGA. AT SAVOONGA...THE AREAS MOST LIKELY TO EXPERIENCE BEACH
EROSION WILL LIKELY BE ALONG THE ROAD TO THE DUMP AND NEAR THE
BOAT LANDING AND WHALING AREA. HIGH SEAS TO 11-13 FEET MAY PRODUCE
SIGNIFICANT BEACH EROSION AT LITTLE DIOMEDE BEGINNING MON. LITTLE
OR NO STORM SURGE IS EXPECTED SO THE THREAT OF COASTAL FLOODING
WILL BE MINIMAL AT LITTLE DIOMEDE OR ON THE NORTH SHORE OF ST
LAWRENCE ISLAND.

ALONG THE NORTHERN COAST OF THE SEWARD PENINSULA FROM SHISMAREF
WEST...NORTH WINDS ARE EXPECTED TO INCREASE TO 30-40 MPH MON...
PRODUCING SEAS 9 TO 11 FEET OFFSHORE. AT SHISMAREF...WAVES TO
AROUND 9 FEET ARE EXPECTED OFFSHORE...DIMINISHING TO AROUND 4 TO 6
FEET AS THEY BREAK ONSHORE. MINOR TO MODERATE BEACH EROSION IS
POSSIBLE AT SHISMAREF...BUT IT IS EXPECTED TO BE LESS SEVERE THAN
AT SAVOONGA OR LITTLE DIOMEDE. COASTAL FLOODING IS UNLIKELY AT
SHISHMAREF WITH LITTLE OR NO STORM SURGE EXPECTED.

STRONG WINDS AND SEAS ARE EXPECTED TO BEGIN DIMINISHING WED.

COASTAL HAZARD MESSAGE WILL BE ISSUED LATER TODAY.

&&

.FIRE WEATHER...
ISOLATED THUNDERSTORMS IN PARTS OF THE INTERIOR THIS
AFTERNOON/EVENING AND AGAIN SUN AFTERNOON/EVENING.

&&

.HYDROLOGY...
NONE

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

RF SEP 11