Small Craft Advisory 624, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 AM ADT WED AUG 10 2005

.DISCUSSION...UPPER LEVEL RIDGE HAS SHIFTED A LITTLE EASTWARD BUT
REMAINS STRONG. THE WEATHER FRONT WE HAVE BEEN WATCHING THE LAST FEW
DAYS IN THE EASTERN ALEUTIANS THROUGH NUNIVAK ISLAND HAS PUSHED INTO
THE KUSKOKWIM DELTA AND WESTERN BRISTOL BAY. HOWEVER IT IS WEAKENING
AND SHOULD DISSIPATE BY FRIDAY.

STILL A SIGNIFICANT AMOUNT OF MARINE STRATUS OVER THE GULF OF ALASKA
AND PRINCE WILLIAM SOUND. EXPECT IT TO PERSIST.

THE UPPER LEVEL LOW NORTHWEST OF ATTU WILL MOVE SOUTHEASTWARD AND
BE OVER KISKA SATURDAY. THIS WILL BE WORTH WATCHING DUE TO THE FACT
THAT THE GFS MODEL HAS BEGUN TO INCREASE THE STRENGTH OF THIS LOW
OVER THE CENTRAL ALEUTIANS THIS WEEKEND OVER EACH OF THE LAST MODEL
RUNS. HOWEVER THE ETA AS WELL AS BOTH EUROPEAN MODELS DO NOT
ANTICIPATE SUCH A SPIN UP OF THIS LOW. STAY TUNED FOR MORE DETAILS AS
THIS LOW PROGRESSES.

AN INTERESTING FEATURE OF THE LAST FEW MODEL RUNS IS THAT THERE HAS
BEEN A LARGE AMOUNT OF HIGH CAPE VALUES FORECAST TO STRETCH FROM THE
COPPER RIVER BASIN INTO THE SUSITNA VALLEY AND DOWN TO THE KENAI
PENINSULA. IN SPITE OF HIGH CAPE VALUES CONVECTION IS CONSIDERED
UNLIKELY AT THIS TIME. THIS IS DUE TO THE VERY WARM TEMPERATURES
ALOFT SUPPRESSING CONVECTION ALONG WITH RELATIVELY HIGH CIN
(CONVECTIVE INHIBITION) VALUES. RELATED TO THE CIN VALUES, THE
CONVECTIVE TRIGGER TEMPERATURES FROM RECENT ANCHORAGE AND MCGRATH
SOUNDINGS HAVE SHOWN THAT TEMPERATURES WOULD NEED TO APPROACH OR
EXCEED 100 FOR CONVECTION TO DEVELOP. THIS IS A STRONG HIGH - BUT NOT
NEARLY THAT STRONG.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE 138.
FIRE WEATHER...NONE.

EZ AUG 05