000
FXAK68 PAFC 151332
AFDAFC

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 AM AKST SUN FEB 15 2009

.ANALYSIS AND UPPER LEVELS...
AT THE SURFACE...THE MAIN FEATURE OF INTEREST IS A 980 MB LOW LOCATED
JUST SOUTHEAST OF SAINT PAUL. A FRONT ASSOCIATED WITH THIS LOW
STRETCHES OVER THE ALASKA PENINSULA AND INTO THE WESTERN GULF OF
ALASKA. WEAK RIDGING IS LOCATED OVER THE EASTERN GULF OF ALASKA. A
985 MB NORTH PACIFIC LOW IS LOCATED NEAR 47N 163E.

IN THE UPPER LEVELS...AN ARCTIC VORTEX IS LOCATED OVER EASTERN
SIBERIA WITH A TROUGH EXTENDING THROUGH THE BERING SEA AND EASTERN
ALEUTIANS. RIDGING IS LOCATED OVER THE ALASKA MAINLAND AND THROUGH
THE EASTERN GULF OF ALASKA. A ROBUST SHORTWAVE IS LOCATED OVER THE
WESTERN ALEUTIANS. DUE TO THE POSITIONING OF THESE
SYSTEMS...SOUTHWESTERLY FLOW CONTINUES ACROSS THE AREA.

.MODEL DISCUSSION...
MODELS INITIALIZED WELL THIS MORNING WITH GOOD AGREEMENT THROUGH 00Z
WEDNESDAY. ONE EXCEPTION PERTAINS TO A TRIPLE POINT LOW EXPECTED TO
DEVELOP NEAR KODIAK ISLAND MONDAY MORNING. THE NAM AND GFS SOLUTIONS
ARE OUTLIERS...WHEREAS THE ECMWF/UKMET SOLUTIONS PROVIDE A GOOD MEAN
SOLUTION. ACCORDINGLY...THE MORNING FORECAST WAS CONSTRUCTED USING
THE ECMWF SOLUTION THROUGH WEDNESDAY.

.SHORT TERM FORECAST...
.SOUTHCENTRAL...
THE AFOREMENTIONED FRONT IS MAKING ITS WAY NORTHWARD THIS
MORNING...CONSTITUTING THE MAIN FORECAST PROBLEM ACROSS SOUTHCENTRAL
IN THE SHORT TERM. PRECIPITATION ASSOCIATED WITH THIS FRONT HAS
OVERSPREAD THE MAJORITY OF THE AREA...WITH A SNOW RAIN MIX FALLING
ALONG COASTAL AREAS AND SNOW FURTHER INLAND. DEEP SOUTHERLY FLOW
ACCOMPANYING THE FRONT IS LEADING TO UPSLOPE SNOW ALONG THE ALASKA
RANGE...ALTHOUGH EXPECT ACCUMULATIONS TO REMAIN BELOW CRITERIA LEVELS
AT THIS POINT. ACROSS THE ANCHORAGE BOWL...EXPECT DOWNSLOPING TO
LIMIT PRECIPITATION TO NOTHING MORE THAN A FEW FLURRIES. ONE FINAL
CONCERN IS THE WIND FORECAST FOR ANCHORAGE. AT THIS TIME THE PRESSURE
GRADIENT IS EXPECTED TO REMAIN HIGHEST FROM ANCHORAGE SOUTH...MEANING
GUSTY TURNAGAIN ARM WINDS WILL LIKELY REMAIN OVER THE INLET. ANY
GUSTY WINDS THAT MAKE IT INTO TOWN HAVE THE POTENTIAL TO MIX DOWN
MUCH WARMER AIR THAN WOULD OTHERWISE MAKE IT TO THE SURFACE. WINDS
WILL BE DECREASING THROUGH CHANNELED TERRAIN AND HIGHER ELEVATIONS
TONIGHT...AS THE FRONT DISSIPATES AND THE PRESSURE GRADIENT BEGINS
RELAXING.


.SOUTHWEST...
AS THE LOW CONTINUES TO MOVE INLAND TODAY STRONG WIND AND SNOW WILL
LEAD TO BLIZZARD CONDITIONS OVER PORTIONS OF BRISTOL BAY AND THE
KUSKOKWIM DELTA. GUSTY WINDS AND SNOW WILL CONTINUE OVER THE
REMAINDER OF SOUTHWEST TODAY...BUT CONDITIONS SHOULD BE IMPROVING AS
WE HEAD INTO THIS AFTERNOON. WARM AIR AHEAD OF THE LOW WILL CREATE A
RAIN AND SNOW MIX ACROSS THE ALASKA PENINSULA...BUT SHOULD CHANGE
BACK TO ALL SNOW BY TONIGHT ONCE COLD AIR WRAPS BACK INTO THE AREA.
CONDITIONS ACROSS SOUTHWEST WILL BE IMPROVING THROUGH THE DAY ON
MONDAY...WITH LIGHTER WINDS AND SCATTERED SNOW SHOWERS THROUGH
TUESDAY AS HIGH PRESSURE BUILDS IN FROM THE NORTHWEST.

.BERING SEA AND ALEUTIANS...
STRONG NORTHERLY WINDS ON THE BACKSIDE OF THE LOW CONTINUE TO CREATE
PROBLEMS ACROSS THE PRIBILOFS...WITH BLIZZARD CONDITIONS CONTINUING
THROUGH TODAY. STRONG NORTHERLY FLOW ACROSS THE EASTERN ALEUTIANS
WILL BE SWITCHING PRECIPITATION BACK TO SNOW...WITH BLOWING SNOW
POSSIBLE THIS AFTERNOON INTO TONIGHT. ELSEWHERE...EXPECT SCATTERED
RAIN AND SNOW SHOWERS TO PERSIST THROUGH TODAY. AS THE LOW SOUTHWEST
OF SHEMYA MOVES ALONG THE CHAIN ON MONDAY...RAIN AND SNOW WILL BE ON
THE INCREASE ACCOMPANIED BY GUSTY SOUTHERLY FLOW.


.LONG TERM FORECAST...
AS PREVIOUSLY MENTIONED...MODELS CONTINUE TO HINT AT A MORE AMPLIFIED
PATTERN IN THE EXTENDED. A RIDGE IS EXPECTED TO BUILD OVER MAINLAND
ALASKA BY MIDWEEK WITH FAST SOUTHWEST TO NORTHEAST FLOW DEVELOPING.
AS A RESULT...A PROGRESSIVE WEATHER PATTERN IS EXPECTED TO CONTINUE
ACROSS THE AREA.


.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...BLIZZARD WARNING...155 161 195
MARINE...GALE WARNING...120 130 132 155 170 172 176 179
                        352 412 413 414
         HEAVY FREEZING SPRAY WARNING...165 179 412 414
FIRE WEATHER...NONE

NRH FEB 09