Small Craft Advisory 537, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
140 PM ADT THU JUN 21 2007

.ANALYSIS AND UPPER LEVELS...
THIS AFTERNOON...A HUGE RIDGE OF HIGH PRESSURE OVER NORTH PACIFIC
EXTENDS NORTH INTO THE EASTERN ALEUTIANS. OVER SOUTHCENTRAL...THERE
IS A WEAKER NORTH SOUTH ORIENTED UPPER LEVEL HIGH WITH A WEAK BUT
IMPORTANT SURFACE TROUGH UNDERLYING IT. A COLD UPPER LEVEL LOW WITH
A WEAK SURFACE LOW UNDERNEATH IS PRESENT AROUND THE YUKON DELTA.
ANOTHER LOW IS PRESENT OVER THE FAR SOUTHWEST BERING.

.MODEL DISCUSSION...
GOOD MODEL AGREEMENT EXISTS.

.SHORT TERM FORECAST...
SOUTHCENTRAL...
MOST IMMEDIATE CONCERN IS FOR THUNDERSTORMS THROUGH THIS (THURSDAY)
EVENING AND THEIR INFLUENCE ON EXISTING FIRES AND ON ANY NEW FIRES.
MAIN FOCUS OF STORMS THROUGH THIS EVENING WILL BE FROM INLAND KENAI
PENINSULA NORTHEAST TO THE CHUGACH AND NORTH TO THE TALKEETNA
MOUNTAINS AND NORTH/WEST PART OF THE COPPER RIVER BASIN. POTENTIAL
FOR THUNDERSTORMS LOOKS ABOUT AS GOOD AS IT EVER GETS AROUND HERE.
ACTIVITY ALREADY GETTING GOING AS OF THIS WRITING. EXPECT
CONVECTION TO BY FAR BE AT ITS MAX LATE THIS AFTERNOON AND THIS
EVENING COMPARED TO UPCOMING DAYS. THE UPPER LEVEL TROUGH NEAR THE
YUKON DELTA WILL APPROACH THE AREA FROM THE WEST TONIGHT...WITH
STRONGER...WETTER...AND COOLER ONSHORE FLOW BEGINNING. THE MARINE
STRATUS WHICH IS CURRENTLY PRESENT OVER THE NORTHERN GULF AND
PRINCE WILLIAM SOUND IS LIKELY TO PERSIST. MOISTURE WILL GRADUALLY
INCREASE INTO THE WEEKEND WITH PRECIPITATION BEING MORE STRATIFORM
IN NATURE RATHER THAN CONVECTIVE.

SOUTHWEST MAINLAND...
THE SOUTHWEST MAINLAND IS IN FOR WET AND COOL WEATHER TO CONTINUE
INTO THE WEEKEND. LOW NEAR THE YUKON DELTA WILL CONTINUE TO BRING
RAIN TO THE BETHEL AREA. RAIN WILL SPREAD EAST INTO THE REST OF THE
SOUTHWEST MAINLAND THURSDAY AS A LOW MOVING EAST ACROSS THE BERING
TONIGHT MERGES WITH THE ALREADY PRESENT LOW AROUND THE YUKON DELTA.
A COLD UPPER LEVEL LOW WILL PERSIST OVER THE SOUTHWEST MAINLAND
INTO THE WEEKEND...KEEPING THE RAIN AROUND.

ALEUTIANS/BERING...
A LOW WITH FAIRLY WEAK WINDS BUT COPIOUS RAIN WILL MOVE EAST ACROSS
THE BERING TONIGHT AND INTO BRISTOL BAY BY FRIDAY NIGHT. THIS WILL
BRING RAIN TO PRETTY MUCH EVERYWHERE SOUTH OF SAINT MATTHEW
TONIGHT. RAIN WILL GRADUALLY TAPER OFF FROM WEST TO EAST FRIDAY AS
HIGH PRESSURE BUILDS INTO THE REGION. SOMEWHAT MOIST NORTHERLY FLOW
WILL CONTINUE OVER THE EASTERN BERING/ALEUTIANS THROUGH THE WEEKEND
AS A RESULT OF THE UPPER LEVEL LOW OVER THE SOUTHWEST MAINLAND.
RAIN WILL MOVE BACK INTO THE WESTERN ALEUTIANS ON SUNDAY WITH HIGH
PRESSURE SQUEEZED IN BETWEEN THESE TWO AREAS.

.LONG TERM FORECAST...
NOT MUCH CONFIDENCE IN ANYTHING BEYOND THIS WEEKEND. IN
GENERAL...IT LOOKS LIKE THE COLD UPPER LEVEL LOW OVER SOUTHWEST
ALASKA WILL GRADUALLY WEAKEN. WEAK HIGH PRESSURE WILL PROBABLY BE
OVER THE EASTERN BERING...WITH UNSETTLED WEATHER AND LOW PRESSURE
OVER THE CENTRAL TO WESTERN BERING/ALEUTIANS.

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

FOISY JUN 07