Small Craft Advisory 61, NWS Anchorage, AK

AREA FORECAST DISCUSSION SOUTHWEST ALASKA
1200 PM AST SUN JAN 16 2005

.DISCUSSION...HIGH PRESSURE OVER NORTHERN ALASKA WITH A LARGE LOW
COMPLEX OVER THE NORTH PACIFIC NORTH TO THE ALEUTIAN CHAIN AND GULF
OF ALASKA. AN ARCTIC BOUNDARY DIVIDES THE TWO FEATURES ALONG THE
SOUTH CENTRAL COAST TO SOUTHWEST ALASKA. THIS IS CREATING A MODERATE
TO STRONG SURFACE PRESSURE GRADIENT ALONG THE SOUTH CENTRAL COAST
ALLOWING FOR THE INCREASE IN NORTHERLY SURFACE WINDS. SKIES ARE CLEAR
TO THE NORTH OF THE BOUNDARY. AREAS OF FOG THIS MORNING OVER SOUTH
CENTRAL NEAR THE KNIK AND MATANUSKA RIVERS. SHOWERS MOVING WITH
DISTURBANCES CIRCULATING THE LOW COMPLEX. MODERATE TO STRONG
NORTHEAST WINDS OVER MUCH OF THE AREA.

AN UPPER LEVEL LOW MOVING SOUTH THROUGH THE YUKON TODAY WITH A RIDGE
OVER THE WEST COAST OF THE LOWER 48. THE RIDGE WILL IMPEDE THE
SOUTHERLY PROGRESSION OF THE UPPER LOW. THIS WILL ALLOW THE UPPER LOW
TO DIG SOUTHWEST OVER SOUTH CENTRAL ALASKA MONDAY BEFORE SETTLING IN
THE WESTERN GULF TUESDAY. IN THE MEANTIME...A RIDGE OF HIGH PRESSURE
OVER SOUTH CENTRAL ALASKA GETS SQUEEZED INTO THE BERING SEA BY
MONDAY.

THIS SCENARIO WILL CREATE A STRONG WIND EVENT THROUGH THE COPPER
RIVER DELTA AND THOMPSON PASS AREAS BEGINNING LATER TODAY AND
TONIGHT. THERE IS SOME UPPER LEVEL SUPPORT TONIGHT INTO TOMORROW
MORNING IN THE MEANS OF COLD AIR ADVECTION AS WELL AS MODERATE
NORTHERLY WINDS ALOFT. AT THE SURFACE...A TROUGH OF LOW PRESSURE
DEEPENS THROUGH MONDAY INTENSIFYING THE SURFACE PRESSURE GRADIENT
ALONG THE SOUTH CENTRAL GULF COAST. AS THE UPPER LOW DIGS INTO THE
WESTERN GULF MONDAY AFTERNOON AND EVENING...THE UPPER LEVEL SUPPORT
BECOMES UNFAVORABLE FOR A STRONG EVENT. HOWEVER...A 980 MB LOW
DEVELOPS IN THE NORTHERN GULF KEEPING THE SURFACE PRESSURE GRADIENT
VERY FAVORABLE ENOUGH FOR POSSIBLE LOW END WARNING CRITERIA THROUGH
TUESDAY MORNING. IN ADDITION TO THESE AREAS...MODERATE TO STRONG
NORTHEAST WINDS THROUGH THE MATANUSKA VALLEY WILL BE PRESENT
BEGINNING TONIGHT AND REMAINING THROUGH TUESDAY MORNING.

A LARGE UPPER LEVEL LOW OVER THE NORTH PACIFIC SOUTH OF THE ALEUTIAN
CHAIN TO SLOWLY MOVE EAST AND JOIN WITH THE UPPER LEVEL LOW IN THE
WESTERN GULF BY TUESDAY NIGHT. THIS WILL REDEVELOP A SURFACE LOW OVER
THE GULF. A TROUGH OF LOW PRESSURE MOVES INTO THE WESTERN BERING
TUESDAY AFTERNOON WITH AN ASSOCIATED SURFACE FRONT AND SLOWLY MOVES
THROUGH THE BERING SEA THROUGH THURSDAY. AN UPPER LEVEL LOW IN THE
NORTHERN PACIFIC IN PHASE WITH THIS TROUGH IN THE BERING SEA WILL
EVENTUALLY PUSH THE UPPER LEVEL LOW OVER THE WESTERN GULF INLAND
THURSDAY WITH THE SURFACE LOW FOLLOWING THEN DISSIPATING FRIDAY.
PRECIP ACROSS SOUTH CENTRAL ALASKA WILL BE CONFINED TO THE EAST OF
THE UPPER LEVEL LOW MONDAY NIGHT THROUGH WEDNESDAY. PRECIP WILL
BECOME MORE WIDESPREAD TO SOUTH CENTRAL THURSDAY WHEN THE LOW WORKS
INLAND. OVER THE BERING SEA...MOST PRECIP WILL FOLLOW THE FRONT
TUESDAY THROUGH FRIDAY. HOWEVER...AN EASTERLY WAVE WILL MOVE ACROSS
THE ALEUTIAN CHAIN TONIGHT THROUGH TUESDAY TO MEET UP WITH THE FRONT
TUESDAY IN THE WESTERN ALEUTIANS.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...BLIZZARD WARNING TONIGHT THROUGH TUESDAY ZONE 131
         HIGH WIND WARNING BEGINNING THIS AFTERNOON ZONE 135
MARINE...HEAVY FREEZING SPRAY 2B1 2C 3A 4 4A 8 14
         GALE WARNING 3A 3C 4 5A
FIRE WEATHER...NONE

JN JAN 05