Small Craft Advisory 449, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 AM ADT THU JUN 2 2005

.DISCUSSION...

VERTICALLY STACKED LOW PRESSURE CENTER HAS BEGUN TO MOVE SOUTHEAST OF
THE ALEUTIANS THIS MORNING. A TROUGH FROM THE UPPER LOW HAS FORMED
ANOTHER LOW WELL SOUTHWEST OF THE CHAIN. ABUNDANT MOISTURE IS
STREAMING ACROSS THE AKPEN ON SOUTHEAST FLOW...A RIDGE PERSISTS OVER
THE GULF OF ALASKA...AND CONVECTIVE DEBRIS FROM AFTERNOON AND EVENING
SHOWERS PERSISTS INLAND.

THE PATTERN CHANGE WILL BE HAPPENING OVER THE NEXT FEW DAYS. MODELS
ARE IN EXCELLENT AGREEMENT IN BRINGING THE UPPER ALEUTIAN LOW TO
ROUGHLY 50 N IN RESPONSE TO A DIVING JET STREAM...AND THEN ELONGATING
IT HALFWAY ACROSS THE GULF TONIGHT BEFORE SPLITTING INTO TWO DISTINCT
LOWS FRI MORNING. BY SATURDAY MORNING THE EASTERN UPPER LOW WILL SIT
OVER THE QUEEN CHARLOTTE ISLANDS AND THE WESTERN WILL BE SOUTH OF
ADAK.  BY THAT TIME THEY WILL BE VERTICALLY STACKED OVER SURFACE
LOWS...SEPARATED BY A RIDGE AXIS ACROSS THE AKPEN.

ALL OF THIS ACTIVITY SOUTH OF THE FORECAST AREA IS CRITICAL IN
BRINGING THE INLAND THERMAL TROUGH/THETA E RIDGE SOUTH TO THE
ANCHORAGE FORECAST AREA. SHOWERS CAN BE EXPECTED ACROSS NORTHERN
PORTIONS EACH AFTERNOON AND EVENING THROUGH SAT...ALTHOUGH SPOTTY
THUNDER WILL BE LIMITED TO THE KUSKOKWIM TODAY...AND CAPE MAY ALSO BE
SUPPORTIVE OVER THE KENAI AND ANCHORAGE ZONES. BY FRIDAY CHANCES
IMPROVE FOR THUNDER AS THE THERMAL RIDGE POKES ACROSS MUCH OF THE
REGION SOUTH OF THE ALASKA RANGE. INCREASED SOLAR INSOLATION WITH
LESS EARLY CLOUD COVER SHOULD ALSO IMPROVE CHANCES AND THIS CONTINUES
SATURDAY.

ALSO DURING THIS PERIOD...SHOWERS DIMINISH OVER THE AKPEN AS THE LOW
SOUTH OF ADAK BRINGS RAIN AND WIND TO THE CENTRAL AND EASTERN
ALEUTIANS FRI NIGHT INTO SAT.

IN THE EXTENDED...AN EASTERLY WAVE MOVES INTO THE COPPER RIVER SUNDAY
AND SPREADS SHOWERS ACROSS SOUTH CENTRAL AS IT MOVES THROUGH THE
THERMAL RIDGE. THE LOW IN THE ALEUTIANS WILL BRING A FRONT ACROSS THE
AKPEN SUNDAY AND INTO THE NORTHERN GULF MONDAY. AS THE LOW MOVES EAST
NEXT WEEK...EAST FLOW SETS UP WITH RAIN FOR KODIAK AND THE COAST
THROUGH THE MIDDLE OF THE WEEK. MEANWHILE...THE THERMAL TROUGH
STRETCHES ACROSS THE KUSKOKWIM SO SHOWERS AND THUNDER CAN BE EXPECTED
THERE INTO THE MIDDLE OF THE WEEK. OUT WEST...CONDITIONS IMPROVE
EARLY NEXT WEEK AS RIDGING BUILDS INTO THE BERING.

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

DS JUN 05