Small Craft Advisory 216, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
200 PM AKDT WED MAR 12 2014

.ANALYSIS AND UPPER LEVELS...
THE MAIN STEERING UPPER LOW IS CENTERED OVER THE NORTHERN BERING
SEA. THERE IS A LOW JUST SOUTH OF THE ALASKA PENINSULA. THE OCCLUDED
FRONT WITH THIS LOW IS ALONG 150 WEST LONGITUDE OVER THE NORTHEAST
PACIFIC...THEN CURVES WESTWARD OVER THE GULF OF ALASKA TO KODIAK
ISLAND...THEN "BENDS BACK" OVER THE ALASKA PENINSULA. VERY COLD AIR
IS SITUATED TO THE NORTHWEST OF THIS BENT BACK OCCLUSION.

.MODEL DISCUSSION...
THE NUMERICAL MODELS ARE IN GOOD AGREEMENT. THE GFS AND ECMWF ARE
VERY CLOSE...AND THIS BOLSTERS CONFIDENCE IN THE FORECAST. EVEN THE
NAM LOOKS FAIRLY GOOD...IF MAYBE A BIT FAST WITH THE LOW MOVING
ACROSS THE GULF OF ALASKA.

.SHORT TERM FORECAST...
FOR SOUTH CENTRAL ALASKA...THE OCCLUDED FRONT WILL WORK ITS WAY
NORTH ACROSS THE GULF TONIGHT AND THURSDAY. SIGNIFICANT PRECIPITATION
IS EXPECTED FOR COASTAL AREAS WITH THIS FRONT...STARTING AS SNOW AND
THEN TRANSITIONING TO RAIN FOR MANY AREAS AS WARM AIR PUSHES IN.
INLAND AREAS WILL SEE LITTLE PRECIPITATION WITH DOWN-SLOPE DRYING.
WINDS ALONG TURNAGAIN ARM AND NEARBY HIGHER ELEVATIONS WILL INCREASE
WITH THE FRONT TO MINIMAL WARNING LEVELS (GUSTS TO 75 MPH). THE LOW
WILL MOVE INTO THE GULF LATER THURSDAY INTO THURSDAY NIGHT. BEHIND
THIS LOW IS SIGNIFICANTLY COLD AIR. POSSIBLE BLOWING SNOW ISSUES ARE
EXPECTED BEGINNING THURSDAY NIGHT ON KODIAK AND FRIDAY MORNING FOR
THE KACHEMAK BAY AREA WITH THE ARRIVAL OF COLD AIR BEHIND THIS LOW.
LATER FRIDAY AND FRIDAY NIGHT THIS COLD AIR WILL REACH ANCHORAGE
WITH SNOW A DEFINITE POSSIBILITY. COLDER DRIER AIR WILL PUSH ACROSS
SOUTH CENTRAL ALASKA ON SATURDAY.

FOR SOUTHWEST ALASKA...SNOW AND BLOWING SNOW WILL BE ON TAP FOR MUCH
OF THE AREA TONIGHT INTO THURSDAY WITH THE ARRIVAL OF THE BENT-BACK
OCCLUSION (AND THEN ITS REMNANTS BY THURSDAY AFTERNOON). WARM AIR
WILL INTRUDE INTO THE EASTERN PORTIONS OF THE SOUTHWEST ALASKA
TONIGHT...BUT THEN COLD AIR WILL SURGE BACK EASTWARD ON THURSDAY.

THE MAIN UPPER LOW OVER THE NORTHERN BERING WILL SLIDE EAST THROUGH
SATURDAY. THIS WILL KEEP SOUTHWEST ALASKA IN FAVORABLE DYNAMICS INTO
FRIDAY...THEN A SLOW DRYING TREND THROUGH SATURDAY.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...BLIZZARD WARNING 181.
         HIGH WIND WARNING 101 125.
MARINE...STORM WARNING 119.
         GALE WARNING 120 125 130 131 132 136 137 138 139 141 150
                        155 160 165 170 172 180.
         HEAVY FREEZING SPRAY 150 155 160 165 170 179 180.
FIRE WEATHER...NONE.

LUDWIG MAR 14