Gale Warning 51, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 AM AKST THU JAN 8 2009

.ANALYSIS AND UPPER LEVELS...AN UPPER LEVEL LOW OVER WESTERN CANADA
SHIFTS EAST WITH A TROUGH EXTENDING WEST ACROSS THE STATE AND IS
SLOWLY DROPPING SOUTH. LOW PRESSURE NORTHWEST OF SHEMYA CONTINUES TO
WEAKEN AND RETROGRADE.

AT THE SURFACE...SURFACE HIGH PRESSURE OVER NORTHERN ALASKA CONTINUES
PUSH COLD AIR SOUTH TOWARDS A WEAK TROUGH OF LOW PRESSURE IN THE
GULF. LOW PRESSURE SOUTH OF THE CENTRAL ALEUTIANS WILL MOVE INTO THE
GULF BY THE END OF THE WEEK. THE MOVEMENT OF THIS LOW SHOULD PROLONG
THE PRESSURE GRADIENT ALONG THE MOUNTAINS...KEEPING 15 MPH WINDS
ALONG THE MOUNTAINS AND WIND CHILLS LOW. STRONG HIGH PRESSURE EXISTS
OVER THE BERING.

.MODEL DISCUSSION...THE MODELS CONTINUE TO BE IN GOOD AGREEMENT IN
THE FIRST 48 HOURS. MODEL CONSENSUS MOVES A LOW THAT IS SOUTH OF
DUTCH THIS MORNING NORTHEAST BEFORE WEAKENING TO AROUND 993 MB
SATURDAY MORNING IN THE GULF. ANOTHER NORTH PACIFIC LOW IS ALREADY
EVIDENT ON SATELLITE IMAGERY AND WILL MOVE INTO THE ALEUTIANS OVER
THE WEEKEND.  AS HAS BEEN THE STORY OF THIS PATTERN SHIFT...THE
MODELS ARE STRUGGLING WITH SPECIFICS IN THE MIDTERM...BUT ARE COMING
AROUND TO BETTER PREDICTABILITY. THE KEY QUESTION WILL BE ON HOW
STRONG A RIDGE WILL BUILD OVER THE EAST PACIFIC. A STRONGER RIDGE
WOULD LEAD TO MORE OF MERIDIONAL STORM TRACK...WEAKER WOULD CONTINUE
WITH A NORTHEAST TRACK. THE FORECAST PACKAGE THIS MORNING WAS BASED
OFF OF THE GFS IN THE SHORT TERM AND TRENDED TOWARDS THE EC IN THE
LONG TERM.

.SHORT TERM FORECAST...

SOUTHCENTRAL...HIGH PRESSURE WILL REMAIN ACROSS NORTHERN ALASKA
THROUGH THE WEEKEND. THIS WILL CONTINUE TO KEEP WINDS PRIMARILY OUT
OF THE NORTH...AND TEMPERATURES WELL BELOW NORMAL. THE COLD
TEMPERATURES TODAY...COUPLED WITH LIGHT WINDS...WILL BRING WIND
CHILLS RANGING FROM THE NEGATIVE TEENS TO NEGATIVE 40S. A WIND CHILL
ADVISORY FOR THOMPSON PASS REMAINS IN EFFECT THROUGH FRIDAY AS WINDS
CONTINUE TO GUST TO 20 MPH. AREAS INLAND WILL BE MOSTLY SUNNY TODAY
WHILE COASTAL AREAS WILL KEEP MUCH OF THE STRATUS AND LOW CLOUDS
AROUND. CLOUDS  AND WARMER TEMPERATURES WILL INCREASE INLAND AS NORTH
PACIFIC SYSTEMS WORK THEIR WAY INTO THE GULF.

SOUTHWEST...NORTHEAST FLOW WILL REMAIN THROUGH THE WEEKEND FOR
SOUTHWEST MAINLAND. COLD TEMPERATURES CONTINUE TO HAVE A STRONG HOLD
ACROSS ON THE AREA...AND REMAIN THE COLDEST IN THE KUSKOKWIM VALLEY.
WIND CHILL ADVISORIES ARE IN EFFECT FOR BRISTOL BAY THROUGH THIS
AFTERNOON...PRIMARILY ALONG THE SOUTHERN COAST WHERE WINDS SPEEDS ARE
GREATEST.  A WIND CHILL ADVISORY REMAINS IN EFFECT FOR THE KUSKOKWIM
DELTA UNTIL FRIDAY. ACROSS THE CHAIN AND WESTERN ALEUTIANS...CHANCES
FOR LIGHT SNOW SHOWERS WILL CONTINUE AS A NORTH PACIFIC LOW PASSES TO
THE SOUTH.

.LONG TERM FORECAST...CONFIDENCE FOR SPECIFICS REMAINS LOW BEYOND
THIS WEEKEND. NATIONAL AND MODEL GUIDANCE ARE STILL HOLDING ONTO
STRONG SOUTHERLY FLOW ACROSS THE EAST BY THE MIDDLE OF NEXT WEEK
WHICH SIGNALS A WARMING TREND FOR SOUTHCENTRAL AND A COOLING TREND
FOR SOUTHWEST.

.AER/ALU...WATCH/WARNING SUMMARY

PUBLIC...NONE
MARINE...GALE WARNING...120 132 155 170 179 351 352 412 413
HEAVY FREEZING SPRAY...121 130 138 140 141 150 160 165 179 185 411
412 413 414
FIRE WEATHER...NONE

SSS/DS JAN 09