Small Craft Advisory 515, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 PM AKDT FRI JUN 27 2008

.MODEL DISCUSSION...
THE MODELS HAVE A SIMILAR SOLUTION IN THE GULF AND MAINLAND ALASKA
THROUGH SUNDAY. MODELS ARE STILL HAVING PROBLEMS COMING TO A COMMON
SOLUTION OVER THE BERING SEA. UKMET AND GFS MODELS ARE IN GOOD
AGREEMENT THROUGH SUNDAY WITH THE NAM BEING THE OUTLYER OF THE GROUP.

.ANALYSIS AND UPPER LEVELS...
AN UPPER LOW IN THE SOUTHERN GULF CONTINUES TO MAINTAIN AN ONSHORE
FLOW INTO SOUTHCENTRAL ALASKA AND HAS KEPT THE AREA SOUTH AND EAST OF
THE ALASKA AND ALEUTIAN RANGES MOSTLY CLOUDY WITH SCATTERED SHOWERS
ALONG THE COAST.

AN EASTERLY WAVE OVER THE ALASKA RANGE CONTINUES TO MOVE WEST. A
THERMAL LOW OVER THE NORTHERN INTERIOR HAS EXTENDED A THERMAL TROUGH
INTO THE SOUTHWEST INTERIOR. THE VORTICITY ASSOCIATED WITH THE
EASTERLY WAVE WILL MOVE INTO THE KUSKOKWIM VALLEY THIS EVENING AND
HELP TRIGGER ISOLATED THUNDERSTORMS OVER THE AREA.

THE SURFACE RIDGE OVER THE BERING SEA CONTINUES TO BE PUSHED EAST BY
THE LOW OVER THE NORTHWEST PACIFIC.

.SHORT TERM FORECAST...
THE UPPER AIR PATTERN IS NOT EXPECTED TO CHANGE MUCH OVER THE NEXT
FEW DAYS. THE UPPER RIDGE OVER THE NORTHERN HALF OF THE STATE WILL
REMAIN THERE THROUGH MONDAY. THE UPPER LOW OVER THE GULF OF ALASKA
WILL MOVE INTO THE NORTHERN GULF SATURDAY NIGHT THEN WEAKEN INTO A
TROUGH ALONG THE COAST SUNDAY AND MONDAY.

AT THE SURFACE...
SOUTHCENTRAL AND GULF OF ALASKA...
A RIDGE OF HIGH PRESSURE OVER SOUTHEAST ALASKA AND THE EASTERN GULF
WILL GRADUALLY BUILD INTO THE REST OF THE GULF AND THE CENTRAL GULF
COAST BY SATURDAY NIGHT AND WILL EVENTUALLY FORM A CLOSED HIGH OVER
THE NORTHERN GULF SUNDAY AND MONDAY. THE SOUTHERLY FLOW OVER
SOUTHCENTRAL REGION WILL GRADUALLY WEAKEN THROUGH SATURDAY NIGHT. THE
CLOUDS WILL PARTIALLY CLEAR THROUGH THE WEEKEND THROUGH SCATTERED
SHOWERS WILL CONTINUE TO DEVELOP LATE IN THE DAY.

SOUTHWEST ALASKA...
THE EASTERLY WAVE OVER NORTHERN SUSITNA VALLEY WILL SETTLE INTO THE
KUSKOKWIM VALLEY TONIGHT AND SATURDAY THEN WILL DISSIPATE SUNDAY.
WIDESPREAD RAIN WILL SPREAD INTO THE KUSKOKWIM VALLEY TONIGHT AND
INTO THE INLAND AREAS OF BRISTOL BAY ZONE SATURDAY. RAIN IS EXPECTED
TO CHANGE TO SHOWER SUNDAY. SHOWERS OVER THE KUSKOKWIM DELTA WILL END
TONIGHT AS A MID LEVEL RIDGE DEVELOPS ALONG THE COAST TONIGHT.

BERING SEA...
A MODERATE LOW OVER THE NORTHWEST PACIFIC WILL WILL BECOME NEARLY
STATIONARY 150 MILES SOUTHWEST OF ATTU SATURDAY. A TROUGH EXTENDING
EAST OF THE LOW WILL SWING NORTH THROUGH THE ALEUTIANS SUNDAY AND
INTO THE BERING SEA MONDAY.

.LONG TERM FORECAST...
THE UPPER TROUGH OVER THE CENTRAL GULF COAST WILL MOVE NORTH AND FORM
A CLOSED LOW OVER SOUTHCENTRAL ALASKA TUESDAY AND OVER NORTHWEST
ALASKA WEDNESDAY.

A WEAK THERMAL TROUGH IS EXPECTED TO DEVELOP OVER SOUTHCENTRAL ALASKA
BY MIDWEEK. MORE CLOUDS AND SHOWERS WILL MOVE BACK INTO THE AREA
THROUGH THE BEGINNING OF NEXT WEEK.

MODEL ARE NOT IN VERY GOOD AGREEMENT OVER THE BERING SEA THEREFORE A
LONG TERM PROJECTION IS NOT POSSIBLE.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...NONE.
FIRE WEATHER...NONE

NM JUN 08