Small Craft Advisory 251, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
500 AM AKDT WED MAR 20 2013

.ANALYSIS AND UPPER LEVELS...
AN UPPER LOW OVER THE NORTHERN YUKON TERRITORY IS KEEPING NORTHWEST
FLOW OVER MUCH OF THE STATE. THERE IS ALSO AN UPPER LOW OVER THE
KAMCHATKA PENINSULA AND ANOTHER SOUTH OF THE ALEUTIAN
ISLANDS...SQUEEZING UPPER RIDGING BETWEEN THE LOWS.

MUCH OF THE STATE IS UNDER CLEAR SKIES THIS MORNING AS OFFSHORE FLOW
DOMINATES. THERE ARE SOME GUSTY GAP WINDS THROUGHOUT THE SOUTHERN
MAINLAND...WHILE THE REMAINDER OF THE STATE IS SEEING RELATIVELY
LIGHT WINDS WITH A WEAK PRESSURE GRADIENT.

.MODEL DISCUSSION...
MODELS ARE IN DECENT AGREEMENT UNTIL THE END OF THE SHORT TERM WHEN
MUCH LARGER DIFFERENCES ARE NOTED ESPECIALLY OVER THE BERING SEA.
WITH NO SIGNIFICANT FEATURES TO AFFECT THE AREA IN THE NEXT FEW
DAYS...THE DIFFERENCES ARE RELATIVELY BENIGN. USED THE ECMWF AND NAM
IN THE SHORT TERM...AND ECMWF FOR THE EXTENDED FORECAST PERIOD.

.SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA...
OFFSHORE FLOW AND MOSTLY SUNNY TO SUNNY SKIES WILL CONTINUE ACROSS
SOUTHCENTRAL ALASKA TODAY AND INTO THURSDAY BEFORE A LOW MOVES INLAND
NEAR THE KUSKOKWIM DELTA AND BRINGS A CHANCE OF SNOW TO MUCH OF THE
AREA. AS THE SURFACE PRESSURE GRADIENT WEAKENS TODAY...GAP WINDS WILL
IN TURN DECREASE.

SOUTHWEST ALASKA/ALEUTIANS/BERING SEA...
A WEAK DISTURBANCE IS MOVING SOUTHWARD THROUGH THE SOUTHWEST MAINLAND
AND WILL BRING SOME LIGHT SNOW WITH IT. THE GAP FLOWS THROUGH THE
ALASKA PENINSULA WILL GRADUALLY DECREASE TODAY AS THE LOW IN THE GULF
OF ALASKA WEAKENS. A LOW OVER THE KAMCHATKA PENINSULA WILL KEEP SOME
STRONGER WINDS OVER THE WESTERN BERING SEA AND WESTERN
ALEUTIANS...OTHERWISE WINDS WILL BE FAIRLY LIGHT OVER THIS REGION.

.LONG TERM FORECAST...
AN ACTIVE WEATHER PATTERN WILL PERSIST THROUGH THE WEEKEND WITH THE
JET STREAM OVER THE ALEUTIANS AND SOUTHERN MAINLAND DURING THAT TIME.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE WARNING 121 126 127 130 132 137.
         HEAVY FREEZING SPRAY WARNING 121 126 127 128 129 130 138 140
                                      141.
FIRE WEATHER...NONE.

SCHRECK