Winter Storm Watch 1, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
200 PM AKST WED JAN 15 2014

.ANALYSIS AND UPPER LEVELS...
SAT IMAGERY AND RADAR SHOWS A WARM FRONT STRETCHING ACROSS THE AK PEN
TO ALONG THE NORTH GULF COAST. RAIN WAS EVIDENT ALONG THE COAST WITH
SNOW INLAND. BRISK GAP FLOW WAS ALSO EVIDENT ACROSS TURNAGAIN ARM.
SNOW WAS OBSERVED ACROSS THE AK PEN AND EASTERN BRISTOL BAY. A WEAK
UPPER TROUGH AND SURFACE LOW OVER THE WESTERN ALEUTIANS PRODUCED SNOW
SHOWERS.

THE TROUGH ASSOCIATED WITH THE WARM FRONT MOVES NORTH TONIGHT. A
SHORT WAVE ASSOCIATED WITH SURFACE LOW TO APPROACH THE GULF MOVES TO
THE NORTH GULF COAST THU NIGHT. THE LONG WAVE CONTINUES TO DIG OVER
THE NORTH PACIFIC AND TAKES ON A NEGATIVE TILT AS THE MAIN VORTEX
MOVES TO NEAR THE AK PEN FRI AFTERNOON AND THE ASSOCIATED TROUGH DIGS
TO THE SE. AT THIS TIME A STRONG SE JET EXTENDS FROM THE SE GULF TO
OVER SOUTHCENTRAL ALASKA. THE JET PUSHES EAST SAT AS THE LOW NEAR AK
PEN MOVES NE WHILE ITS ASSOCIATED TROUGH MOVES OVER SE AK.

.MODEL DISCUSSION...
MODEL ALL INITIALIZED WELL ON THE GENERAL SYNOPTIC SURFACE PATTERN
AND 300 MB RH FIELDS. THE ECMWF CONTINUES TO BE THE MOST CONSISTENT
AND REASONABLE THROUGH THE SHORT TERM. SO IN GENERAL WILL CONTINUE TO
LEAN THAT WAY THIS FORECAST PACKAGE. THOUGH THE NAM IS THE MAIN
OUTLIER...IT DOES HANDLE THE PRECIPITATION PATTERN AND GAP FLOW OVER
SOUTHCENTRAL THE BEST OVER THE NEXT 12 HRS OR SO.

.SHORT TERM FORECAST...
SOUTHCENTRAL ALASKA...
TEMPS WILL WARM THROUGH TONIGHT AS THE WARM FRONT MOVES NORTH. SNOW
WILL SPREAD NORTH THROUGH TONIGHT AND WILL MIX WITH FREEZING RAIN
OVER ZONES 101/111/145. FREEZING RAIN TO A LESSER EXTEND IS POSSIBLE
THIS EVENING ACROSS THE INTERIOR/NORTH KENAI. RAIN WILL BE GENERALLY
ALONG THE COAST WITH SOME MIXED RAIN AND SNOW IN COLD POCKETS NEAR
THE COAST. THERE MAY BE A BRIEF BREAK IN PRECIPITATION BEHIND THE
WARM FRONT TONIGHT...BUT IT SHOULD RAPIDLY FILL IN AS THE NEXT LOW
AND ASSOCIATED FRONTAL TROUGH MOVES INTO THE GULF THU. CONTINUED
WARMING OCCURS THU THROUGH FRI AND MIXED PRECIPITATION TYPES BECOME
MORE WIDESPREAD INLAND. THE COPPER RIVER BASIN MAY ALSO SEE SOME
LIGHT FREEZING RAIN THU AND FRI. RAIN ALONG THE NORTH GULF COAST
SHOULD BE HEAVY AT TIMES FRI WITH STRONG UPPER JET SUPPORT.

SOUTHWEST ALASKA...
SOUTHWEST ALASKA...
SNOW WILL CONTINUE TO SPREAD NORTH AND WEST ACROSS THE REGION WITH
THE WARM FRONT TONIGHT. FREEZING RAIN WITH WARMING ALOFT WILL DEVELOP
OVER BRISTOL BAY THIS AFTERNOON TO A LESSER EXTEND IN THE LOWER
KUSKOKWIM VALLEY TONIGHT. PRECIPITATION WILL DIMINISH ACROSS THE AREA
THU. WARM ADVECTION WITH NEXT SURGE OF MOISTURE AND STRONG LOW
APPROACHING THE AK PEN FRI WILL BRING WIDESPREAD MIXED PRECIPITATION
TYPES ACROSS THE THE REGION WITH INCREASED CHANCES FOR FREEZING RAIN
OVER THE DELTA.

ALEUTIANS/BERING SEA...
THE SURFACE LOW JUST NORTH OF THE CENTRAL ALEUTIANS WILL MEANDER
SLOWLY SOUTHWEST TO NEAR SHEMYA THROUGH THURSDAY. GUSTY GALE-FORCE
WINDS AROUND THE LOW CENTER WILL BE PRIMARILY FROM THE NORTH AND
EAST...EXCEPT FOR WESTERLY WINDS ACROSS THE WESTERN CHAIN. THE
POTENTIAL FOR BLIZZARD CONDITIONS INCREASE ACROSS THE EASTERN
ALEUTIANS FRI MORNING AS LOW MOVES NORTH TOWARD THE AK PEN AND THE
OCCLUDED FRONT MOVES TO JUST WEST OF COLD BAY. BLOWING SNOW CONCERNS
MAY ALSO BECOME AN ISSUE LATER FRI FOR THE PRIBILOFS. FOR NOW WILL
ISSUE A BLIZZARD WATCH FOR THE EASTERN ALEUTIANS AND INTRODUCE
BLOWING SNOW FOR THE PRIBILOFS.

.LONG TERM FORECAST...
STRONG CHINOOK CONDITIONS WILL IMPACT THE WESTERN
KENAI...ANCHORAGE...AND THE MATANUSKA VALLEY FRIDAY INTO FRIDAY
NIGHT...WITH HEAVY RAIN ALONG THE GULF COAST AND A POTENTIAL HEAVY
WET SNOW/RAIN MIX FOR INTERIOR SOUTH AND EAST FACING SLOPES OF THE
ALASKA RANGE. STRONG WINDS WILL LIKELY IMPACT HIGHER ELEVATIONS OF
ANCHORAGE AND TURNAGAIN ARM AS WELL. AFTER A BRIEF COOLING TREND
DROPPING TEMPERATURES BACK TO BELOW FREEZING SATURDAY NIGHT AND
SUNDAY WITH A GOOD CHANCE OF SNOW...STRONG SOUTHERLY FLOW WILL ONCE
AGAIN PUSH WARM AND WET CONDITIONS TOWARD THE GULF COAST AND BRING
ANOTHER CHANCE AT HEAVY RAIN ALONG THE GULF COAST AND CHINOOK
CONDITIONS INLAND. TEMPERATURES WILL OSCILLATE FROM THE UPPER 20S TO
MID 30S THROUGHOUT THE WEEKEND INTO THE MIDDLE OF NEXT WEEK...WITH
SEVERAL OPPORTUNITIES FOR RAIN AND SNOW.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...BLIZZARD WATCH 185
MARINE...GALES 119 120 130 131 138 150 155 165 170 171 172 173 174
178 181 185
         HEAVY FREEZING SPRAY 179 180 185.
FIRE WEATHER...NONE.

RMC JAN 14