Small Craft Advisory 540, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 AM ADT FRI JUN 22 2007

.ANALYSIS AND UPPER LEVELS...

UPPER LEVEL RIDGES OVER EASTERN RUSSIA AND THE EASTERN HALF OF AK
THIS MORNING...WITH LOWS OVER WESTERN AK AND KAMCHATKA. AT THE
SURFACE...LOWS ARE OVER THE CENTRAL BERING AND WESTERN AK...WITH A
RIDGE OVER THE AKPEN AND NORTHEASTERN GULF COAST.

.MODEL DISCUSSION...

MODELS ARE IN GOOD AGREEMENT WITH THE GFS REPRESENTING THE CONSENSUS
SOLUTION. FORECASTS TREND IN THAT DIRECTION.

.SHORT TERM FORECAST...

IN THE WEST...HIGH PRESSURE GRADUALLY BUILDS INTO THE AREA WITH LOW
CLOUDS AND FOG PERSISTING THROUGH SAT. AT THAT POINT A FRONT ENTERS
THE WESTERN BERING WITH RAIN FOR THE WESTERN AND CENTRAL ALEUTIANS
THROUGH SUN. THE EASTERN BERING WILL HAVE RAIN TODAY AS THE BERING
LOW MOVES TO THE AKPEN. A LOW FROM EASTERN RUSSIA MOVES TO WESTERN AK
SUN. THIS FEATURE SPREADS RAIN ACROSS THE EASTERN BERING THROUGH THAT
PERIOD.

OVER SOUTHWEST AK...THE BERING LOW AND EASTERN RUSSIA LOW WILL KEEP
PRECIPITATION OVER THE AREA THROUGH SUN WITH ONLY BRIEF BREAKS ON
SAT.

SOUTH AND EAST OF THE AK RANGE...THE THERMAL RIDGE MIGRATES TO THE
TALKEETNAS AND EASTERN AK RANGE THIS AFTERNOON. THESE AREAS WILL BE
THE FOCUS FOR AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS. THE
EASTERN AK AND BERING LOWS WILL BRING CLOUD COVER AND RAIN TO WESTERN
PORTIONS OF THE AK RANGE TODAY. ON SAT THIS WILL SPREAD OVER ALL
AREAS WEST OF THE TALKEETNAS WHILE THE CONVECTIVE FOCUS SHIFTS TO THE
WRANGELLS. ONSHORE OVERRUNNING FLOW DEVELOPS AS A NORTH GULF COAST
RIDGE OVER THE WEEKEND. THIS SHOULD BRING PLENTY OF RAIN TO COASTAL
AREAS AND INTO THE SUSITNA VALLEY THROUGH THE WEEKEND. SOME
DOWNSLOPING WILL DEVELOP OVER SOUTH CENTRAL SAT...DIMINISHING SUN. AS
THE BERING LOW DIVES SOUTHEAST OVER THE AKPEN...THE ONSHORE FLOW
MOVES MORE TOWARD THE KENAI AND PRINCE WILLIAM SOUND AREAS SUN. THIS
WILL BRING HEAVIER RAIN TO THESE AREAS...WITH SOME BLEEDING ACROSS
THE CHUGACH INTO THE COPPER RIVER. CLOUD COVER CUTS OFF MOST
CONVECTION AT THIS POINT.

.LONG TERM FORECAST...

BY TUE ALL PRECIP IN THE BERING HAS MOVED EAST WITH HIGH PRESSURE
REMAINING FOR THE REST OF THE WEEK. PRECIPITATION OVER SOUTHWEST AK
LASTS INTO MIDWEEK AND THEN DIMINISHES. A STRENGTHENING RIDGE FROM
THE EAST PUSHES PRECIP BACK WEST OF THE TALKEETNAS AND PRINCE WILLIAM
SOUND BY MIDWEEK. THERMALLY INDUCED LOW PRESSURE MAY THEN SET UP
CONVECTIVE POTENTIAL OVER MUCH OF THE AK RANGE AND TALKEETNAS FOR THE
END OF THE WEEK.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE
MARINE...NONE
FIRE WEATHER...RED FLAG 141

DS JUN 07