Small Craft Advisory 158, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
400 PM AST FRI FEB 22 2008

.MODEL DISCUSSION...MODELS ARE IN GOOD AGREEMENT THROUGH THE WEEKEND.
THE BIGGEST DIFFERENCE IS WITH THE WEAK LOW MOVING INTO THE GULF
DURING THE WEEKEND. EACH MODEL HAS A LITTLE DIFFERENT SOLUTION TO THE
STRENGTH AND POSITION OF THE LOW. GFS HAS WOBBLED A LITTLE IN ITS
CONSISTENCY AS WELL BUT NOT TOO BADLY. THIS IS NOT A HUGE ISSUE
BECAUSE IT IS NOT A LARGE LOW AND EVERY POSSIBLE PATH INDICATED BY
THE MODELS KEEP IT IN THE CENTRAL TO EASTERN GULF WHICH WILL KEEP THE
GENERAL PATTERN FOR THE AREA THE SAME.

.ANALYSIS AND UPPER LEVELS...UPPER LEVEL PATTERN HAS A BUILDING HIGH
AMPLITUDE RIDGE OVER THE BERING SEA AND A HIGH AMPLITUDE TROUGH
THROUGH THE GULF OF ALASKA. THE MAIN JET STREAM RUNS SOUTH OF THESE
FEATURES AND WILL REMAIN WELL SOUTH OF THE AREA THROUGH EARLY NEXT
WEEK. A WEAKENING LOW SOUTH OF KODIAK WILL DISSIPATE OVERNIGHT AS A
NEW LOW SOUTH OF THE GULF MOVES NORTHWARD OVER THE NEXT FEW DAYS.
A STRONG LOW SOUTH OF SHEMYA IS HEADING TOWARD THE WESTERN ALEUTIANS
BUT IS MAKING SLOW PROGRESS AND WILL WEAKEN AS IT MOVES NORTHWARD.

.SHORT TERM FORECAST...THE HIGH PRESSURE IN THE BERING SEA COMBINED
WITH THE LOW SOUTH OF KODIAK IS BRINGING GUSTY NORTHWEST WINDS AND
BLOWING SNOW TO THE KUSKOKWIM DELTA AND ALASKA PENINSULA. THESE
CONDITIONS SHOULD IMPROVE OVERNIGHT BUT NOT COMPLETELY CEASE.
SOUTHWEST ALASKA WILL CONTINUE TO SEE SNOW SHOWERS TONIGHT BUT THEY
SHOULD DIMINISH SATURDAY.
THE FRONT AHEAD OF THE LARGE LOW WILL IN THE FAR WEST WILL BRING
STORM FORCE WINDS TO THE WESTERN ALEUTIANS TONIGHT. PRECIPITATION
WILL BEGIN AS SNOW AND AREAS OF BLOWING SNOW ARE LIKELY OVERNIGHT
BEFORE THE WARMER TEMPERATURES ARRIVE TOMORROW AND TURN MOST OF THE
PRECIPITATION TO RAIN.
DOWNSLOPING IN SOUTH CENTRAL HAS KEPT THE ANCHORAGE BOWL AND MAT-SU
VALLEY DRY TODAY AND NO SIGNIFICANT PRECIPITATION IS EXPECTED IN
THESE AREAS THROUGH THE WEEKEND.

.LONG TERM FORECAST...THE OVERALL PATTERN IS SHIFTING RIGHT NOW AND
SHOULD GET LOCKED IN PLACE BY THE END OF THE WEEKEND. THE UPPER LEVEL
RIDGE IN THE BERING SEA WILL REMAIN IN PLACE AND A SURFACE HIGH WILL
BUILD INTO NORTHERN ALASKA BY SUNDAY. THIS WILL HELP KEEP THE WEATHER
SYSTEMS ALONG THE CENTRAL AND WESTERN ALEUTIANS THIS WEEKEND. THE
GULF COAST MAY SEE SOME SNOW SHOWERS IN CONJUNCTION WITH THE LOW
MOVING INTO THE GULF THIS WEEKEND BUT THE MORE SIGNIFICANT LOW WILL
NOT ARRIVE INTO THE GULF FROM THE SOUTH UNTIL LATE MONDAY OR TUESDAY.
THIS LOW WILL HAVE A DIFFICULT TIME MOVING TOO FAR NORTH AS WELL DUE
TO THE SURFACE HIGH IN THE INTERIOR AT THAT TIME. EXPECT STRONG WINDS
ALONG AND NEAR THE GULF COAST LATE MONDAY THROUGH TUESDAY.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE 172 175 185.
         STORM 176.
         HEAVY FREEZING SPRAY 150 155 165 179 185.
FIRE WEATHER...NONE.

FEB 08