Small Craft Advisory 1088, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
558 AM AST TUE DEC 25 2007

.ANALYSIS AND UPPER LEVELS...
A STRONG AREA OF LOW PRESSURE IS MOVING EAST THROUGH THE CENTRAL
GULF ALASKA AND IS BEGINNING TO WEAKEN THIS MORNING. A WELL DEFINED
SURFACE TROUGH EXTENDS NORTH FROM THE LOW INTO THE EASTERN KENAI
PENINSULA AND INTO THE TALKEETNA MOUNTAINS. STRONG COLD ADVECTION IS
OCCURRING ON THE WEST SIDE OF THIS TROUGH AXIS ALONG WITH SNOW FROM
THE KENAI NORTH TO THE SUSITNA VALLEY AS MOIST SOUTHEASTERLY FLOW
OVERRIDES THE COLD NORTHWEST FLOW. THERE ARE ALSO SOME LOCALLY GUSTY
NORTHWEST WINDS FROM CHANNELED TERRAIN OF THE WESTERN SUSITNA VALLEY
SOUTH TO THE KODIAK ISLAND AREA. BLIZZARD CONDITIONS ARE TAPERING
OFF IN KODIAK...BUT BLIZZARD CONDITIONS ARE EXPECTED TO REEMERGE
TODAY OVER PORTIONS OF THE KENAI PENINSULA AS THE LOW PRESSURE AND
THE TROUGH AXIS DISCUSSED ABOVE MOVES EAST AND THE NORTHWEST WINDS
INCREASE WITH SNOW CONTINUING.

OUT WEST...THERE IS A SMALL SCALE SURFACE LOW PRESSURE JUST
NORTHWEST OF THE PRIBILOFS...AND A MAJOR LOW PRESSURE GATHERING
STRENGTH SOUTHWEST OF THE ALEUTIANS.

.MODEL DISCUSSION...
NAM/WRF CONTINUES TO INITIALIZE THE GULF LOW BETTER THAN ANY OTHER
MODEL...AND WILL SIDE WITH IT IN THE IMMEDIATE SHORT TERM IN THE
EAST. REGARDING THE UPCOMING MAJOR LOW OUT WEST...MODELS AGREE WELL
UP UNTIL IT GETS TO NEAR DUTCH HARBOR WEDNESDAY MORNING...THEN PART
WAYS A BIT. GFS APPEARS TO HAVE A GOOD MIDDLE OF THE ROAD TRACK
WHICH TAKES THE LOW CENTER ALONG OR JUST SOUTH OF THE EASTERN
ALEUTIANS/ALASKA PENINSULA THROUGH THURSDAY AS THE LOW TRANSFORMS
INTO AN ELONGATED TROUGH AXIS. FOR TODAY...THERE IS A SMALL SCALE
BUT POTENT LOW JUST WEST NORTHWEST OF THE PRIBILOFS ABOUT WHICH THE
MODELS HAVE LITTLE CLUE.

.SHORT TERM FORECAST...
SOUTHCENTRAL...
THE STRONG LOW PRESSURE IN THE NORTH CENTRAL GULF WILL CONTINUE TO
SEND SNOW NORTH INTO SOUTHCENTRAL TODAY. LOCALIZED GUSTY NORTHWEST
WINDS ON THE BACK SIDE OF A TROUGH AXIS ARE DEVELOPING...WITH
BLIZZARD CONDITIONS EXPECTED AROUND KACHEMAK BAY THIS MORNING AND
PORTIONS OF THE EASTERN KENAI LATE THIS MORNING THROUGH THIS
AFTERNOON. SEE WARNING STATEMENTS FOR FURTHER DETAILS. WE ARE STILL
EXPECTING SOME SNOWFALL FROM THE ANCHORAGE BOWL NORTH INTO THE
SUSITNA VALLEY AND COPPER RIVER BASIN TODAY AND THIS EVENING AS THE
MOIST SOUTHEAST FLOW OVERRUNS THE COLD NORTHWEST FLOW AT LOWER
LEVELS. BLIZZARD CONDITIONS HAVE FINALLY SUBSIDED AT KODIAK THANKS
TO THE SNOWFALL ENDING. HOWEVER...FOR KODIAK VERY STRONG WINDS
ESPECIALLY IN CHANNELED TERRAIN WILL PERSIST THIS MORNING WITH
LOCALIZED BLOWING SNOW. COLD ARCTIC HIGH PRESSURE WILL BRING A BREAK
IN THE ACTION FOR WEDNESDAY AND WEDNESDAY NIGHT...BEFORE ANOTHER LOW
PRESSURE AND ASSOCIATED FRONT MOVES IN LATE WEDNESDAY NIGHT AND
THURSDAY.

SOUTHWEST MAINLAND...
ARCTIC HIGH PRESSURE WILL BRING TRANQUIL WEATHER AND VERY COLD
TEMPERATURES TO THE SOUTHWEST MAINLAND THROUGH WEDNESDAY. NORTHEAST
WINDS WILL BEGIN TO INCREASE WEDNESDAY AFTERNOON AS A LOW PRESSURE
REACHES THE ALASKA PENINSULA FROM THE WEST. THIS LOW WILL BRING
PRECIPITATION...STRONG WINDS...AND WARMER TEMPERATURES ESPECIALLY
NEAR THE COAST FOR WEDNESDAY NIGHT AND THURSDAY.

BERING SEA/ALEUTIANS...
A SMALL SCALE BUT POTENT LOW IS BRINGING GUSTY WINDS AND SNOW
SHOWERS TO THE CENTRAL TO EASTERN BERING AND PRIBILOFS TODAY. THE
NEXT LOW PRESSURE TO AFFECT THE REGION WILL BE MUCH LARGER SCALE
WITH STRONG UPPER JET SUPPORT. THIS LOW WILL TRACK ALONG OR JUST
SOUTH OF THE ALEUTIANS LATE TODAY THROUGH WEDNESDAY NIGHT. THIS LOW
WILL BRING IN MUCH WARMER AIR. HOWEVER...BLIZZARD CONDITIONS ARE
POSSIBLE AS PRECIPITATION BEGINS OVER THE ALASKA PENINSULA TONIGHT
BEFORE PRECIPITATION TURNS TO RAIN. WILL ALSO HAVE TO WATCH THE
PRIBILOFS CLOSELY TONIGHT THROUGH WEDNESDAY NIGHT WITH THIS
SYSTEM...AS THEY WILL STAY IN THE COLD AIR WITH FAIRLY SIGNIFICANT
PRECIPITATION AND WINDS.

.LONG TERM FORECAST...
VERY COLD SHOWERY NORTHWEST FLOW IS LIKELY FOR THE BERING AND
ALEUTIANS THURSDAY ONWARD. UPPER LEVEL CYCLONIC FLOW WILL BE PRESENT
FROM THURSDAY ONWARD OVER THE SOUTHERN MAINLAND AND GULF OF
ALASKA...WITH A FEW AREAS OF SURFACE LOW PRESSURE EMBEDDED IN THIS
CYCLONIC FLOW. EXPECT SEASONAL TEMPERATURES WILL OCCASIONAL SHOTS OF
SNOW.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...BLIZZARD WARNING ZONES 121 125.
         BLIZZARD WATCH ZONE 181.
MARINE...STORM WARNING ZONES 130 132 138 150 155 165 170 351 352.
         GALE WARNING ZONES 120 121 129 140 141 160 171 172 175 179
          413 414.
         HEAVY FREEZING SPRAY WARNING ZONES 120 121 125 129 130 132
          138 140 141 150 160 165 180 185 411 412 414.
FIRE WEATHER...NONE.

FOISY DEC 07