Small Craft Advisory 86, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
200 PM AKST MON JAN 27 2014

.ANALYSIS AND UPPER LEVELS...
THERE IS AN UPPER LEVEL LOW SOUTH OF KODIAK ISLAND WITH A TROUGH
EXTENDING ACROSS THE ALASKA PENINSULA INTO THE EASTERN BERING SEA.
THERE IS AN ELONGATED FRONT ALSO ASSOCIATED WITH THIS LOW THAT
STRETCHES ALONG THE NORTH GULF COAST. THERE IS ANOTHER LOW TO THE
WEST OF THE WESTERN ALEUTIANS...WITH A SHORT-WAVE RIDGE OVER THE
CENTRAL ALEUTIANS. THERE IS A STRONG RIDGE OVER WESTERN CANADA THAT
EXTENDS INTO EASTERN AND NORTHERN ALASKA.

.MODEL DISCUSSION...
THE NUMERICAL MODELS ARE IN GOOD AGREEMENT THROUGH 36 HOURS...THEN
BEGIN TO DIVERGE. THE MAIN PROBLEM AREA IS WITH HOW THEY HANDLE THE
SPLITTING OF A TROUGH OVER THE BERING/ALEUTIANS. THE ECMWF AND UKMET
ARE CREATING A LARGER SPLIT...AT 60 HOURS THEY HAVE ONE SURFACE LOW
NEAR SAINT MATTHEW ISLAND AND ONE WELL SOUTH OF THE ALASKA PENINSULA.
AT THE SAME TIME THE GFS HAS ONLY A WEAK FRONT OVER THE NORTHERN
BERING SEA AND THE SOUTHERN LOW IS NEAR THE EASTERN ALEUTIANS/ALASKA
PENINSULA REGION. THE NAM IS SIMILAR TO THE GFS IN THE NORTH AND
SIMILAR TO THE UKMET IN THE SOUTH. THE GEM HAS VIRTUALLY NOTHING IN
THE NORTH AND A LOW IN THE SOUTH SIMILAR TO THE UKMET. A PREFERENCE
WAS GIVEN TO THE ECMWF SOLUTION DUE TO THE ECMWF'S BETTER
PERFORMANCE IN SPLITTING SYSTEMS (DUE TO HIGHER RESOLUTION AND
BETTER DATA ASSIMILATION) AND THE FACT THAT IT IS BACKED UP BY THE
UKMET.

.SHORT TERM FORECAST...
FOR SOUTH CENTRAL ALASKA...THE FRONT ALONG THE GULF COAST WILL
SLOWLY MOVE INLAND TONIGHT INTO TUESDAY THEN DISSIPATE TUESDAY
NIGHT. NOT A WHOLE LOT OF PRECIPITATION IS EXPECTED WITH THIS FRONT.
HOWEVER...COOLER AIR ALOFT WILL FOLLOW THIS FRONT ALLOWING FREEZING
LEVELS TO DROP. ON TUESDAY NIGHT INTO WEDNESDAY THE UPPER LOW THAT
WAS SOUTH OF KODIAK WILL MOVE NORTHEAST ACROSS KODIAK. ON WEDNESDAY
EVENING THIS LOW WILL COME UP AGAINST THE CANADIAN RIDGE AND
DISSIPATE AS IT REACHES SOUTH CENTRAL ALASKA. THURSDAY LOOKS DRY AS
THE RIDGE CONTINUES TO DRIFT WESTWARD.

FOR SOUTHWEST ALASKA...WESTERN ALASKA WILL REMAIN ON THE PERIPHERY
OF THE RIDGE. NOT A WHOLE LOT OF PRECIPITATION IS EXPECTED AS THE
FLOW ALOFT REMAINS EASTERLY OR SOUTHERLY. WINDS WILL BE FAIRLY
BREEZY THROUGH TUESDAY WITH THE CLOSE PROXIMITY TO THE LOW OVER THE
ALASKA PENINSULA INTO THE EASTERN BERING SEA. WEDNESDAY THROUGH
THURSDAY WILL SEE A SLACKENING OF THE GRADIENT AS THE LOW WEAKENS.

FOR THE BERING SEA AND ALEUTIANS...THE PATTERN WILL BE SLIGHTLY
PROGRESSIVE THROUGH THURSDAY. THIS WILL ALLOW A SERIES OF FRONTS TO
PUSH THROUGH THE AREA FROM THE WEST. THE FIRST FRONT WILL SLIDE
THROUGH THE CENTRAL ALEUTIANS TONIGHT INTO TUESDAY...THEN INTO THE
EASTERN ALEUTIANS LATER TUESDAY INTO WEDNESDAY. THE UPPER TROUGH
BEHIND THIS FRONT WILL PUSH THROUGH THE WESTERN ALEUTIANS ON
TUESDAY. THE NEXT FRONT WILL REACH THE WESTERN ALEUTIANS WEDNESDAY
AND INTO THE CENTRAL ALEUTIANS THURSDAY.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...FLASH FLOOD WATCH 131.
MARINE...STORM WARNING 178.
         GALE WARNING 132 138 150 155 160 165 170 172 173 174 180
                     181 185.
FIRE WEATHER...NONE.

LUDWIG JAN 14