Small Craft Advisory 62, NWS Anchorage, AK

AREA FORECAST DISCUSSION SOUTHWEST ALASKA
1200 PM AST MON JAN 17 2005

.DISCUSSION...HIGH PRESSURE OVER EASTERN ALASKA INTO NORTHWEST CANADA
WITH A LARGE LOW COMPLEX OVER THE NORTH PACIFIC NEAR 160W. A TROUGH
OF LOW PRESSURE IS IN THE GULF OF ALASKA AS WELL WITH A ARCTIC
BOUNDARY ALONG THE GULF COAST EXTENDING INTO SOUTHWEST ALASKA.
PRESSURE GRADIENT RATHER STRONG NEAR THIS BOUNDARY.
ADDITIONALLY...MODERATE TO STRONG NORTH TO EAST WINDS ALOFT MAKING
FOR STRONG SURFACE WINDS. HAVE SOME WARNINGS THROUGH NORTH-SOUTH
ORIENTED GAPS OVER SOUTH CENTRAL ALASKA. OTHER AREAS THROUGH SOUTH
CENTRAL WILL BE NEAR WIND ADVISORY CRITERIA. THESE CONDITIONS WILL
LIKELY LAST THROUGH TONIGHT AND START TO WANE TOMORROW THROUGH
WEDNESDAY. PLENTY OF COLD AIR FILTERING OVER THE MAINLAND. AREAS OF
WIND CHILL NEAR ADVISORY CRITERIA TONIGHT OVER SOUTHWESTERN ALASKA.

AT UPPER LEVELS...HIGH PRESSURE NEAR THE BERING STRAIT AND A LOW OVER
NORTHWEST CANADA WITH A TROUGH EXTENDING INTO SOUTH CENTRAL ALASKA. A
LARGE LOW COMPLEX IS PRESENT OVER THE NORTH PACIFIC. A SHORT WAVE
TROUGH TO ROTATE AROUND THE NORTH PACIFIC LOW AND PUSH A SHORT WAVE
RIDGE TO THE COAST WEAKENING THE TROUGH OVER SOUTH CENTRAL ALASKA BY
TUESDAY EVENING. THE SHORT WAVE TROUGH WILL HELP THE LOW IN THE NORTH
PACIFIC MOVE INTO THE WESTERN GULF BY WEDNESDAY. THE HIGH AT THIS
TIME MOVES OVER THE NORTHERN INTERIOR. IN THE MEANTIME...A TROUGH
OVER THE WESTERN BERING BECOMES CONNECTED WITH THE POLAR LOW SINKING
SOUTH OVER SIBERIA. THE TROUGH WILL VERY SLOWLY DRIFT EAST OVER THE
BERING SEA WITH A SERIES OF SHORT WAVES MOVING THROUGH IT. THIS
TROUGH WILL EVENTUALLY PULL THE WESTERN GULF LOW BACK TO THE BERING
SEA THURSDAY AND FRIDAY AS A STRONG WAVE MOVES THROUGH THE NORTHERN
PACIFIC. THIS WAVE WILL MOVE INTO THE GULF BY THE WEEKEND WITH THE
TROUGH EXTENDING BACK TO THE PARENT SIBERIAN LOW.

AT THE SURFACE...THE LOW PRESSURE SYSTEM IN THE NORTH PACIFIC PUSHES
A WARM FRONT INTO THE GULF TUESDAY DROPPING THE PRESSURE OVER THE
GULF. WITH THE HIGH PRESSURE OVER THE INTERIOR...A STRONG PRESSURE
GRADIENT WILL REMAIN ALONG THE COAST FOR A FEW DAYS. STRONG NORTHERLY
WINDS THROUGH NORTH-SOUTH ORIENTED GAPS WILL BE PREVALENT. FLOW ALOFT
WILL BE GENERALLY FROM THE EAST AND NORTH TO THE WEST OF THE TROUGH
OVER SOUTH CENTRAL ALASKA THROUGH MUCH OF TOMORROW. AS THE WARM FRONT
WORKS NORTH...FLOW WILL TURN TO THE SOUTH AND SOUTHEAST TUESDAY NIGHT
WITH THE UPPER AND SURFACE LOW BECOME STACKED IN THE WESTERN GULF BY
WEDNESDAY. THE WINDS WILL DROP SOMEWHAT AS YOU LOSE UPPER LEVEL
SUPPORT FOR THE STRONGEST WINDS. SURFACE PRESSURE GRADIENTS TO REMAIN
STRONG THROUGH WEDNESDAY MORNING...BUT WITHOUT THE UPPER LEVEL
SUPPORT EXPECT WINDS TO DROP INTO THE ADVISORY CATEGORIES IN MOST
PLACES. PLACES WHERE ADVISORIES ARE PRESENT WILL LOWER BELOW CRITERIA
BY TOMORROW. THE WARM FRONT WILL ALSO BRING PRECIP TO THE COAST AND
EVENTUALLY INLAND WEDNESDAY NIGHT. LIGHT PRECIP WILL BE ASSOCIATED
WITH THE TROUGH OVER THE BERING SEA THROUGH THE WEEK. THIS TROUGH
MOVES INLAND FRIDAY. THE LOW THAT IS TO MOVE INTO THE GULF BY THE
WEEKEND AND ITS ASSOCIATED UPPER LEVEL TROUGH THROUGH THE BERING SEA
WILL GENERATE LIGHT PRECIP OVER MUCH OF THE FORECAST AREA. ANOTHER
LOW TO CREEP INTO THE WESTERN ALEUTIAN CHAIN OVER THE WEEKEND WITH
STRONG WINDS AND MORE SUBSTANTIAL PRECIPITATION.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...HIGH WIND WARNING THRU TUE ZONE 111
         BLIZZARD WARNING THRU TUE NIGHT ZONE 131
         HIGH WIND WARNING IN VALDEZ THRU TUE NIGHT ZONE 131
         HIGH WIND WARNING THRU TUE NIGHT ZONE 135
MARINE...HEAVY FREEZING SPRAY 2B 2B1 2C 3A 4 4A 6A 8 14
         GALE 3A 3B 3C 4 5A 5B
FIRE WEATHER...NONE

JN JAN 05