Small Craft Advisory 938, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
400 PM AKST MON NOV 25 2013

.ANALYSIS AND UPPER LEVELS...A CUT OFF UPPER LEVEL LOW IN THE CENTRAL
BERING SEA IS WEAKENING INTO A TROUGH WHICH WILL MOVE OVER MAINLAND
ALASKA TUESDAY NIGHT. THE JET STREAM IS BRINGING SOUTH WARM AIR OUT
OF THE PACIFIC TO THE NORTH GULF COAST AND POINTS FARTHER EAST.
AT THE SURFACE A LOW IN THE NORTHERN GULF IS WEAKENING AS IT HEADS
TOWARD PRINCE WILLIAM SOUND TONIGHT. THE LOW IN THE CENTRAL BERING
SEA IS ALSO WEAKENING AS A RIDGE OF HIGH PRESSURE BUILDS IN FRONT HE
NORTHWEST.

.MODEL DISCUSSION...MODELS ARE IN GOOD OVERALL AGREEMENT BUT DO
DIFFER ON SOME ELEMENTS THAT WILL IMPACT THE FORECAST IN SOUTH
CENTRAL ALASKA. THERE ARE TWO ISSUES OF NOTE. THE FIRST IS HOW FAR
WEST THE LOW IN THE GULF TRAVELS AS IT ENTERS PRINCE WILLIAM SOUND.
THIS WILL IMPACT HOW FAR THE ABOVE FREEZING AIR IS ABLE TO MOVE
INLAND. RIGHT NOW IT LOOKS LIKE IT WILL MAINLY BE CONFINED TO THE
COAST BUT IF IT MOVES TOO FAR WEST IT COULD ALLOW SOME WARM AIR ALOFT
TO MAKE IT INTO SOUTH CENTRAL AND PRODUCE SOME AREAS OF LIGHT
FREEZING RAIN. THIS DOES NOT LOOK LIKE THE MOST LIKELY SCENARIO BUT
IT IS A POSSIBILITY WORTH MENTIONING. ON THURSDAY THERE WILL BE
ANOTHER LOW IN THE VICINITY OF PRINCE WILLIAM SOUND. THE STRENGTH AND
MOVEMENT OF THIS LOW WILL DICTATE WHETHER THE COOK INLET THROUGH
MAT-SU REGIONS GET SOME SNOWFALL OR RAPIDLY BEGIN TO CLEAR OUT.
FARTHER WEST THE MODEL AGREEMENT IS GOOD AND THERE ARE NO SIGNIFICANT
CONCERNS BETWEEN MODEL SOLUTIONS.

.SHORT TERM FORECAST...THE LOW IN THE GULF WILL BRING SOME RAIN TO
THE NORTH GULF COAST...TRANSITIONING TO SNOW FARTHER WEST. VALDEZ
WILL BE THE EXCEPTION WHERE THE PRECIPITATION TYPE SHOULD REMAIN
MOSTLY SNOW. WEST OF THE KENAI AND CHUGACH MOUNTAINS THE
PRECIPITATION SHOULD REMAINS SNOW...THOUGH SOME AREAS SUCH AS
TURNAGAIN ARM MAY WARM UP ENOUGH TUESDAY TO CHANCE OVER TO RAIN. AS
MENTIONED IN THE PREVIOUS SECTION...THERE IS A SLIGHT CHANCE THAT
ENOUGH WARM AIR ALOFT COULD DROP SOME LIGHT FREEZING RAIN INTO THE
ANCHORAGE OR MAT-SU AREAS.

.LONG TERM FORECAST...THE MODELS CONTINUE TO PAINT THE SAME GENERAL
PICTURE IN THE LONG TERM PATTERN HEADING INTO THIS WEEKEND. THE
BERING SEA RIDGE WILL SLIDE OVER THE MAINLAND BY SATURDAY...SETTING
UP A BLOCKING PATTERN. CONFIDENCE IS GAINING THAT BELOW NORMAL
TEMPERATURES AND PRECIPITATION WILL ONCE AGAIN TAKE OVER A MAJORITY
OF THE STATE ON SATURDAY...AND LIKELY CONTINUE INTO NEXT WEEK.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE 119.
FIRE WEATHER...NONE.

NOV 13