Freezing Rain Advisory 13, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
435 AM AKST SUN FEB 15 2015

.ANALYSIS AND UPPER LEVELS...
THE FLOW ALOFT LOOKS SLIGHTLY MORE ORGANIZED THIS MORNING. THE
MAJOR PLAYER IN THE UPCOMING FORECAST IS TAKING SHAPE IN THE
PACIFIC. THE CENTER OF THE CYCLONIC FLOW CONTINUES TO BE THE
WEAKENING UPPER LOW NOW SOUTH OF THE CENTRAL/EASTERN
ALEUTIANS...HOWEVER TO THE EAST AN IMPRESSIVE LOOKING SHORTWAVE IS
MARCHING NORTH IN A HIGH AMPLITUDE SOUTHERLY FLOW. THE WESTERN
NORTH AMERICA RIDGE IS WELL ESTABLISHED AGAIN AND HAS RECONNECTED
WITH INTERIOR ALASKA RIDGING WHICH SETS THE STAGE FOR THIS WARM
MOIST FRONTAL BOUNDARY.

THE CURRENT SHORTWAVE IS DECAYING AND PUSHING INTO THE SOUTHERN
MAINLAND EARLY THIS MORNING BRINGING SOME WIDESPREAD RAIN/SNOW
FOLLOWED BY WARMER SOUTHERLY WINDS IN MOST AREAS.

&&

.MODEL DISCUSSION...
NUMERICAL GUIDANCE IS CONVERGING ON A SOLUTION FOR THE UPCOMING
LOW/FRONT IN THE PACIFIC. THERE IS GREAT AGREEMENT WITH LOW TRACK
AND STRENGTH AS THE LOW CENTER APPROACHES THE EASTERN
ALEUTIANS/ALASKA PENINSULA BUT SOME TRACK DIFFERENCES DO OCCUR
ONCE THE SYSTEM OCCLUDES IN THE BERING SEA. OTHERWISE GUIDANCE
HANDLES THE STRUCTURE OF THE SYSTEM MOSTLY THE SAME. FROM A
FRONTAL PERSPECTIVE THE ONLY DIFFERENCES THAT ARISE IN THE
PRECIPITATION FIELD ARE NORMAL DIFFERENCES IN AMOUNT OF DOWNSLOPE
DRYING ALONG THE LINES OF MODEL RESOLUTION.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
THE REMNANTS OF THE UPPER TROUGH PASSING THROUGH THIS MORNING ARE
BRINGING LIGHT FREEZING RAIN TO ANCHORAGE AND THE WESTERN
MATANUSKA VALLEY. PRECIPITATION SHOULD BE LIGHT AND WINDS WILL
FLIP AROUND TO SOUTHERLY THIS MORNING AND QUICKLY WARM SURFACE
TEMPERATURE INTO THE MID 30S. DRIER CONDITIONS WILL FOLLOW FOR THE
REMAINDER OF THE DAY WITH SOME BREAKS IN THE CLOUDS. A STRONG WARM
FRONT APPROACHES THE SOUTHCENTRAL TODAY...SPREADING RAIN ALONG
THE NORTH GULF COAST TONIGHT INTO MONDAY...WITH SNOW AT HIGHER
ELEVATION. TURNAGAIN ARM AND HILLSIDE WINDS WILL RAMP UP THIS
AFTERNOON AND EVENING COINCIDENT WITH THE FRONT AS WELL. THE COOK
INLET REGION WILL REMAIN MOSTLY DRY AND DOWNSLOPED FOR THIS EVENT.
THE FRONT PUSHES INLAND ON MONDAY NIGHT INTO TUESDAY BRINGING
ANOTHER PUSH OF SOUTHERLY WINDS ACROSS MOST LOCATIONS.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
A STRONG FRONT AND LOW PRESSURE SYSTEM APPROACHING THE EASTERN
ALEUTIANS AND ALASKA PENINSULA THIS AFTERNOON WILL SPREAD A MIXED
BAG OF PRECIPITATION OVER THE MAINLAND. THE ALEUTIAN RANGE WILL
REMAIN LARGELY DOWNSLOPED AND DRY WITH STRONG CROSS-BARRIER FLOW
AND GUSTY WINDS...ESPECIALLY THROUGH CHANNELED TERRAIN. PRECIPITATION
WILL START AS SNOW FOR THE PENINSULA BEFORE CHANGING TO RAIN AND
DRYING OUT OVERNIGHT INTO MONDAY. INTERIOR BRISTOL BAY WILL SEE
SNOW SPREADING FROM SOUTH TO NORTH THIS EVENING BEFORE A WARM
LAYER PUSHES IN AND CHANGES SNOW TO RAIN AND FREEZING RAIN. THE
FRONT WILL PUSH INTO THE KUSKOKWIM DELTA OVERNIGHT AND BRING A
SIMILAR TRANSITION FROM SNOW TO FREEZING RAIN. THE REMAINDER OF
THE SYSTEM WILL LINGER IN THE AREA THROUGH MONDAY KEEPING SNOW AND
RAIN SHOWERS IN THE FORECAST FOR MOST AREA.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
A FRONTAL BOUNDARY APPROACHING THE ALASKA PENINSULA WILL SPREAD
RAIN AND STRONG EASTERLY WINDS OVER THE EASTERN FOLLOWED BY THE
CENTRAL BERING SEA. AS THE FRONT SWINGS OVER THE PRIBILOF ISLAND
EARLY MONDAY MORNING GUSTY WINDS AND FALLING SNOW BRING ANOTHER
BLOWING SNOW EVENT TO THE AREA. THE FRONT DISSIPATES LATE MONDAY
LEAVING SNOW AND RAIN SHOWERS LINGERING ACROSS THE BERING.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...
THE UPPER LEVEL CLOSED LOW NEAR 41N 178W WILL CONTINUE TO GRADUALLY
MOVE EAST THROUGH NEXT WEEKEND. THIS SYNOPTIC FEATURE WILL CONTINUE
TO SEND SHORTWAVES THROUGH THE EASTERN BERING SEA AND THE
SOUTHWEST/SOUTHCENTRAL ALASKA REGION. THIS WILL BRING WARMER
TEMPERATURES AND MOISTURE WITH CONTINUED SOUTHERLY FLOW THROUGH
THE GULF BEFORE MOVING INTO THE INLAND AREAS. THE NORTHERN GULF
COASTLINES WILL RECEIVE THE MAJORITY OF THE PRECIPITATION.
WHILE...THE ANCHORAGE BOWL AND WESTERN KENAI PENINSULA WILL HAVE
DOWNSLOPE DRYING CONDITIONS. THE INLAND AREAS WILL CONTINUE TO
HAVE SHOWERY PRECIPITATION WITH EACH SHORTWAVE AS THEY PUSH
THROUGH THE REGION HEADING INTO NEXT WEEKEND. THE BERING SEA WILL
CONTINUE IN SHOWERY PRECIPITATION WITH WINDS REMAINING OUT OF THE
NORTH TO NORTHEAST DIRECTION WITH HIGH PRESSURE LOCATED OVER THE
SIBERIAN REGION.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...FREEZING RAIN ADVISORY...101 111 155.
         BLOWING SNOW ADVISORY...195.
MARINE...STORM WARNING...119 120 130 131 132 138 150 155.
         GALE WARNING...125 129 136 137 139 141 160 165 170 171
                        173 179 180 185.
         HEAVY FREEZING SPRAY WARNING...185.
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...MTL
SOUTHCENTRAL ALASKA...MTL
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...MTL
LONG TERM...PLD