Small Craft Advisory 635, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
200 PM ADT SUN AUG 5 2007

.MODEL DISCUSSION...
NUMERICAL MODELS IN EXCELLENT AGREEMENT AGAIN TODAY THROUGH ABOUT
FRIDAY. DIVERGENCES START TO BECOME NOTICEABLE BY NEXT WEEKEND.

.ANALYSIS AND UPPER LEVELS...
THE MONSTER RIDGE OVER THE NORTHEAST PACIFIC CONTINUES TO DRIVE ALL
WEATHER OVER THE TOP INTO ALASKA. UPPER LOW AXIS ALONG THE WEST
COAST OF ALASKA THIS AFTERNOON. ALSO A SHORT WAVE RIDGE OVER THE
CENTRAL BERING SEA. JET STREAM STILL FLOWING NORTHWEST INTO ALASKA
BETWEEN THE WESTERN ALASKA LOW AND THE PACIFIC HIGH...BUT IS
BEGINNING TO BUCKLE LEADING TO A SPLIT (SEE NEXT SECTION).

.SHORT TERM FORECAST...
WESTERN ALASKA UPPER LOW WILL PUSH ACROSS ALASKA TONIGHT AND MONDAY.
THIS WILL COMPLETE THE JET SPLIT BY LATE MONDAY AND THE BERING RIDGE
WILL HOOK UP WITH THE EAST PACIFIC RIDGE AND FORM A FULL LATITUDE
RIDGE ALONG ABOUT 160W LONGITUDE BY MID WEEK...A VERY IMPRESSIVE
FEATURE. ANYWAY...BY LATE MONDAY FLOW ALOFT WILL BECOME NORTHWEST AS
THE TROUGH AXIS MOVES INTO THE YUKON. THIS WILL LEAD TO AN
IMPROVEMENT IN THE WEATHER TOWARD WARMER AND DRIER. WEDNESDAY NIGHT
A SHORT WAVE WILL DROP THROUGH FROM THE NORTH. THIS FEATURE LOOKS
MAINLY DRY IN WHAT BY THIS TIME HAS BECOME NORTH FLOW...BUT IS SHARP
ENOUGH TO POSSIBLY KICK OFF SOME SHOWERS.

.LONG TERM FORECAST...
BY THURSDAY ANY HOPE OF SHOWERS BECOMES EXTREMELY SMALL WITH A LARGE
RIDGE OVER WESTERN ALASKA AND NORTHERLY FLOW OVER MOST OF THE STATE.
PLEASANT AUGUST WEATHER IS ON TAP FOR THE LATER PART OF THE WEEK.
THE AFTERNOON PACKAGE WILL SHOW A DRY SUNNY FORECAST FOR THIS TIME
PERIOD AS CONFIDENCE WAS HIGH ENOUGH TO JUSTIFY A CHANGE IN THE
FORECAST.

BY THE WEEKEND THE MODELS BEGIN TO STRUGGLE WITH HOW TO HANDLE THE
(POSSIBLE) BREAK DOWN OF THE ALASKAN RIDGE. PAST SEVERAL RUNS OF THE
GFS HAVE BEEN FLIP-FLOPPING ON WHETHER OR NOT TO PUSH MOISTURE AND
ENERGY THROUGH THE RIDGE. THE 12Z RUN KEEPS THINGS DRY INTO EARLY
NEXT WEEK FOR SOUTH CENTRAL ALASKA. FOR THE SATURDAY AND SUNDAY
FORECAST...WILL STAY DRY AS LACK OF CONFIDENCE LENDS TO KEEPING THE
FORECAST STATUS QUO.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...STORM WARNING 176.
         GALE WARNING 130 175.
FIRE WEATHER...NONE.

LUDWIG AUG 07