Small Craft Advisory 1, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 AM AKST WED DEC 31 2008

.ANALYSIS AND UPPER LEVELS...

UPPER LEVEL HIGH OVER THE NORTHERN BERING THIS MORNING WITH AN UPPER
LOW OVER NORTHERN CANADA AND AN ASSOCIATED TROUGH EXTENDING TO
SOUTHEAST AK. A WEAK CUT-OFF LOW PERSISTS OVER THE NORTHERN GULF. AT
THE SURFACE...A TROUGH OF LOW PRESSURE OVER THE NORTHERN GULF EXTENDS
TO A LOW EAST OF THE QUEEN CHARLOTTE ISLANDS...WITH HIGH PRESSURE
OVER THE BERING AND NORTH OF THE AK RANGE. A FAIRLY TIGHT PRESSURE
GRADIENT IS LOCATED ALONG THE NORTH GULF COAST.

.MODEL DISCUSSION...

MODELS ARE IN GOOD AGREEMENT FOR SEVERAL DAYS. THE GULF LOW WEAKENS
THROUGH THU ONLY TO REDEVELOP IN THE SAME LOCATION FRI AND THEN
DISSIPATE AGAIN ON SAT. THIS OCCURS AS HIGH PRESSURE PERSISTS OVER
INTERIOR ALASKA. DURING THIS SAME PERIOD A NORTH PACIFIC LOW...
CIRCULATING SOUTH OF KAMCHATKA...BRINGS A WEATHER FRONT ACROSS THE
ALEUTIANS AND INTO THE BERING FROM THE SOUTH...WHICH THEN MAKES
LITTLE HEADWAY AGAINST THE BERING RIDGE. THE FORECAST LEANS TOWARD
THE GFS.

.SHORT TERM FORECAST...

IN THE WEST...HIGH PRESSURE WILL KEEP COLD AIR...LOW CLOUDS AND FOG
OVER MOST OF THE BERING THROUGH THE WEEKEND. THE WESTERN AND CENTRAL
ALEUTIANS WILL BE AFFECTED BY THE FRONT FROM THE KAMCHATKA LOW
THROUGH THE WEEKEND. THIS SYSTEM WILL BRING GALES AND STORMS TO THE
AREA...ESPECIALLY ON THU WHEN SNOW MIXES WITH RAIN. DURING THIS
ENTIRE PERIOD THE EASTERN ALEUTIANS WILL ONLY BE AFFECTED BY LOW
CLOUDS AND FOG...AND THE OCCASIONAL SNOW SHOWER ON EAST TO NORTHEAST
FLOW.

FOR SW AK....COLD AND CLEAR CONDITIONS WILL CONTINUE TODAY WITH HIGH
CLOUDS ARRIVING TONIGHT. A SHORT WAVE FROM NW AK WILL BRING SOME SNOW
SHOWERS TO THE AREA THU INTO FRI...AND THEN THE RIDGE REASSERTS
ITSELF INTO THE WEEKEND.

SOUTH AND EAST OF THE AK RANGE...CLEAR AND COLD CONDITIONS PUNCTUATED
BY AREAS OF FOG ALONG THE KNIK ARM WILL CONTINUE TODAY. STRONG WINDS
THROUGH THOMPSON PASS AND THE COPPER RIVER DELTA WILL GRADUALLY
DIMINISH BY THU AS THE GULF LOW WEAKENS. EXCEPT FOR A FEW SNOW
SHOWERS THU NIGHT INTO FRI FROM THE NW AK SHORT-WAVE...PRECIPITATION
WILL BE LIMITED TO SHOWER ACTIVITY NEAR THE GULF LOW THROUGH THE
WEEKEND. WIDESPREAD HEAVY FREEZING SPRAY IS EXPECTED OVER MARINE
AREAS.

.LONG TERM FORECAST...

HIGH PRESSURE PERSISTS OVER THE BERING INTO NEXT WEEK...WITH SNOW
SHOWERS ON EAST TO NORTHEAST FLOW. SW AK REMAINS FAIRLY DRY WITH SNOW
SHOWERS DEVELOPING JUST OFFSHORE. LOW PRESSURE WILL MOVE INTO THE
NORTHWESTERN GULF SUN NIGHT...BRINGING SNOW TO KODIAK ISLAND AND THE
GULF COAST BEFORE RETREATING BACK INTO THE GULF EARLY NEXT WEEK.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...
MARINE...GALES 121 129 150 172 175
         STORMS 176
      HEAVY FREEZING SPRAY 121 125 129 130 138 140 141 150 160 185
FIRE WEATHER...NONE

DS DEC 08