Small Craft Advisory 115, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 AM AST SAT FEB 9 2008

.MODEL DISCUSSION...
MODELS LOOK GOOD IN THE SHORT TERM OUT WEST THIS EVENING BUT ARE LESS
RELIABLE IN THE EAST.  COMPARISON WITH SATELLITE IMAGERY INDICATES
THAT NONE OF THE 00Z RUNS ARE INITIALIZING WELL ON THE LOW PRESSURE
SYSTEM CURRENTLY SOUTH OF DUTCH HARBOR.  NAM AND ECMWF ARE HINTING AT
THE TRIPLE POINT LOW THAT IS CURRENTLY FORMING BUT GFS HAS NOT PICKED
UP ON THIS FEATURE AT ALL. ALL OF THE MODELS ARE HIGHLY VARIABLE ON
WHICH LOW CENTER WILL DEVELOP AND WHERE IT WILL GO...THOUGH WITH THE
UPPER LEVEL LOW MOVING TO THE WEST THIS WILL PROBABLY CAUSE A MORE
WESTERLY TRACK.  LITTLE CHANGE WAS MADE TO THE CURRENT FORECAST FOR
CONTINUITY REASONS. IN THE LONG TERM...THE MODEL SOLUTIONS ARE PRETTY
VARIABLE.  GFS WANTS TO SPLIT THE LOW OUT WEST INTO SEVERAL CENTERS
AND MOVE THE LOW IN THE EAST ON A DIFFERENT TRACK...THIS IS A CHANGE
FROM THE 12Z SOLUTION WHICH WAS SHOWING BETTER CONTINUITY.  SO IN THE
LONGTERM THE 12Z SOLUTION WAS CHOSEN.

.ANALYSIS AND UPPER LEVELS...
AS FORECAST YESTERDAY THE UPPER LEVEL LOW HAS MOVED FROM THE WESTERN
YUKON OVER MAINLAND ALASKA THIS MORNING. SOUTHWEST FLOW CONTINUES IN
THE GULF WITH THE MAIN JET CURRENTLY OVER THE PANHANDLE.  AS THE LOW
CONTINUES TO MOVE WESTWARD THROUGH TODAY THE MAIN POLAR JET WILL ALSO
MOVE WESTWARD AND BECOME MORE SOUTHERLY AS WELL. THIS WILL ALLOW THE
SURFACE SYSTEMS TO MOVE ONSHORE NEAR CORDOVA AND BRING MORE PRECIP TO
THE SOUTHCENTRAL REGION.  IN THE SATELLITE IMAGERY THIS MORNING A
SURFACE LOW SOUTH OF DUTCH HARBOR HAS ALREADY DEVELOPED A SECONDARY
LOW TO ITS EAST...THIS FEATURE WAS NOT WELL HANDLED BY MODELS SO THE
FORECAST IS A LITTLE UNCERTAIN AT THIS POINT.  HOWEVER THE SECONDARY
LOW HAS THE BENEFIT OF THE UPPER LEVEL JET SUPPORT SO IT WILL
PROBABLY CONTINUE THE NORTHEASTWARD TRACK WHILE THE PRIMARY LOW
SLOWLY FILLS BEHIND IT.

.SHORT TERM FORECAST...
EAST OF THE ALASKA RANGE...GUSTY WINDS CONTINUE IN CHANNELED AREAS
CAUSING WIND CHILL ADVISORY CONDITIONS THROUGH BROAD PASS AND
THOMPSON PASS. BY TOMORROW TEMPERATURES SHOULD BEGIN TO RISE WITH THE
APPROACH OF THE NEXT LOW AND THE RETURN OF SOUTHERLY FLOW.  THIS WILL
ALSO BRING SNOW TO THE GULF COAST AND A CHANCE FOR SNOW TO THE INLAND
ZONES. AMOUNTS ARE NOT EXPECTED TO REACH ADVISORY LEVEL AT THIS
POINT.

WEST OF THE ALASKA RANGE...WIND CHILL ADVISORIES ALSO CONTINUE OUT
WEST AS GUSTY NORTHERLY WINDS OCCUR AHEAD OF THE LOW.  THE FIRST
CHANCE FOR SNOW HAPPENS MONDAY NIGHT WHEN WRAP AROUND MOISTURE BEGINS
TO MOVE INTO THE KUSKOKWIM VALLEY AND ON INTO THE DELTA BY TUESDAY
MORNING. IN THE ALEUTIANS THE WEAK LOW CURRENTLY OVER THE WESTERN
ALEUTIANS WILL DISSIPATE OVER THE NEXT FEW DAYS...BUT ITS NEARLY
STATIONARY LOCATION WILL CONTINUE TO CAUSE SHOWERY AND UNSTABLE
CONDITIONS FOR THE ALEUTIANS THROUGH WEDNESDAY.

.LONG TERM FORECAST...
UNCERTAINTY IS VERY HIGH RIGHT NOW WITH THE MODEL RUNS SO VARIABLE.
HOWEVER MODELS CONTINUE TO FAVOR A MORE WESTERLY TRACK TO IT APPEARS
THAT A SNOWY FORECAST FOR THE MAINLAND IS MORE LIKELY. TEMPERATURES
ALSO APPEAR TO CONTINUE WITH THE WARMING TREND THROUGH THE END OF THE
WEEK.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE
MARINE...HEAVY FREEZING SPRAY 121 125 129 140 185 412 414
         GALES 411 412 413
FIRE WEATHER...NONE

LEWF FEB 08