Small Craft Advisory 97, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
500 AM AKST WED JAN 30 2013

.ANALYSIS AND UPPER LEVELS...
AN UPPER LOW IS MOVING EAST JUST SOUTH OF THE EASTERN ALEUTIANS. A
RIDGE CONTINUES TO BE SITUATED OVER THE EASTERN PACIFIC. BETWEEN
THESE TO FEATURES LOW AND MID LEVEL MOISTURE IS STREAMING NORTH OVER
SOUTHERN ALASKA. AT THE SURFACE...A BROAD WEAKENING LOW IS CENTERED
NORTH OF SAINT PAUL ISLAND. ANOTHER FRONT IS MOVING NORTH FROM THE
NORTHERN PACIFIC. SCATTERED AREAS OF LIGHT SNOW IS FALLING ACROSS
SOUTH ALASKA. PATCHY FOG HAS DEVELOPED ACROSS THE ALASKA
PENINSULA...THE KUSKOKWIM DELTA AND BRISTOL BAY.

.MODEL DISCUSSION...
MODELS ARE IN OVERALL AGREEMENT WITH THE SYNOPTIC PATTERN THROUGH THE
SHORT TERM FORECAST. THERE ARE SUBTLE DIFFERENCES IN HOW FAR NORTH
THE WARM AIR MASS WILL MOVE AND MIX ALONG AND JUST NORTH OF THE
ALASKAN GULF COAST...HOWEVER THEY HAVE TRENDED TOWARD SLIGHTLY COLD
SOLUTIONS. THE NEXT 30 HOURS IS THE MOST CHALLENGING PART OF THE
FORECAST WITH THE POSSIBILITIES FOR RAIN...SNOW...AND FREEZING
PRECIPITATION ACROSS SOUTH CENTRAL. A FEW CHANGES WERE MADE TO
ADVISORY PRODUCTS EARLY THIS MORNING AFTER ANALYZING THE LATEST
COOLING TRENDS OF THE MODEL DATA.

SOUTHCENTRAL ALASKA...
THE FRONT THAT MOVED UP FROM THE CENTRAL GULF YESTERDAY IS NOW
SITUATED ALONG THE GULF COAST. THE AIR MASS ALONG THE COAST WILL
CONTINUE TO MODERATE TODAY. THE COASTAL LOCATIONS WILL SEE SNOW
CHANGING OVER TO RAIN DURING THE AFTERNOON AS TEMPERATURES CONTINUE
TO WARM. IN ADDITION...FREEZING PRECIPITATION WILL BE A PROBLEM FOR
AREAS THAT ALREADY HAVE VERY COLD TEMPERATURES IN PLACE AND WILL BE
SLOWER TO WARM ABOVE THE SURFACE. THE FREEZING RAIN ADVISORY FOR
ANCHORAGE HAS BEEN PUSHED BACK FOR THE TIMING AS THE TEMPERATURES ARE
NOT WARMING AS QUICKLY AS EXPECTED PREVIOUSLY. THE ADVISORY FOR THE
MATANUSKA VALLEY HAS BEEN CANCELLED SINCE TEMPERATURES SHOULD STAY
COLD ENOUGH FOR PRECIPITATION TO BE ALL SNOW. THE FREEZING RAIN
ADVISORY FOR THE WESTERN KENAI PENINSULA HAS NOW BEEN UPDATED TO A
WINTER WEATHER ADVISORY FOR SNOW AND FREEZING RAIN. THE HEAVIEST
PRECIPITATION WILL MOVE OVER THE REGION TODAY THROUGH THURSDAY
AFTERNOON AND THEN TAPER OFF THURSDAY NIGHT.

SOUTHWEST ALASKA...
AN UPPER LEVEL LOW WILL SLOWLY MOVE OVER SOUTHWEST ALASKA THROUGH
FRIDAY. PERIODS SNOW AND RAIN WILL CONTINUE THROUGH THE END OF THE
WEEK. TODAY...SNOW MIXED WITH SLEET IS POSSIBLE FOR THE AREA NORTH OF
DILLINGHAM AND ALSO ALONG THE KUSKOKWIM DELTA. THE KUSKOKWIM VALLEY
WILL SEE ALL SNOW WITH THE HEAVIEST AMOUNTS ACCUMULATING TONIGHT
THROUGH THURSDAY.

ALEUTIANS/BERING SEA...
SCATTERED SNOW AND RAIN WILL CONTINUE THROUGH THE END OF THE WEEK AS
WEAK DISTURBANCES ALOFT MOVE OVER THE BERING.

.LONG TERM FORECAST...
A WET PATTERN CONTINUES THROUGH THE LONG TERM FORECAST AS AN
EXPANSIVE LONG WAVE PATTERN DOMINATES THROUGH NEXT WEEK. TEMPERATURES
WILL CONTINUE TO MODERATE ALONG THE COAST AS ANOTHER SURFACE LOW
MOVES UP FROM THE PACIFIC.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...WINTER WEATHER ADVISORY 121 145
MARINE...GALE WARNING 120 125 130 132 140 185
         HEAVY FREEZING SPRAY 127
FIRE WEATHER...NONE

KH JAN 13