Small Craft Advisory 587, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
1035 AM ADT WED JUL 5 2006

.DISCUSSION...4AM 500 MB CHART LOOKS LIKE THE ONE 24 HRS AGO. LARGE
LOW WESTERN ALEUTIANS HAS NOT MOVED MUCH IN THE LAST DAY OR SO AND A
WEAKER UPPER TROF REMAINS IN PLACE OVER THE NORTHEAST PACIFIC/GULF.
INBETWEEN IS A NICE UPPER HIGH WHICH IS CENTERED OVER BRISTOL BAY
WITH A RIDGE AXIS INTO THE RUSSIAN FAR EAST.

NORTHWEST FLOW ON THE EAST SIDE OF THE HIGH CARRYING SEVERAL WEAK
IMPULES SOUTHEASTWARD. ONE IS PRODUCING VERY CLOUDY CONDITIONS WITH
SOME SCATTERED SHOWER ACTIVITIY OVER MUCH OF SOUTHERN MAINLAND AK.
THERE HAS BEEN SOME THUNDERSTORM ACTION NEAR FAREWELL LAKE AND
PUNTILLIA AS THESE MOIST CONDITIONS RECIEVES SOME LIFT FROM THE
ALASKA RANGE. AS IT LOOKS RIGHT NOW THERE WILL BE A THREAT OF SHOWERS
JUST ABOUT EVERYWHERE FROM BRISTOL BAY EASTWARD WITH THUNDERSTORMS
CONFINED MAINLY TO THE MOUNTAINOUS AREAS.

BREAKOUT FROM THE MARINE STRATUS WILL BE SLOWER ACROSS SOUTHCENTRAL
AND NORTH COAST TODAY DUE TO MORE MID AND HIGHER LEVEL CLOUDINESS
BLOCKING THE SUN. AREAS WEST OF THE AK RANGE WILL RISE INTO THE 70S
DUE WITH MORE SUNSHINE AND A MUCH SHOLLOWER AND LESS EXTENSIVE MARINE
LAYER. IT IS ALSO MORE UNSTABLE WITH THE LIFTED INDEX AT BOTH BETHEL
AND MCGRATH LESS THAN ZERO AT 4 AM. SO ITS PRETTY LIKELY THERE WILL
BE A THREAT OF THUNDERSTORM AND SHOWER ACTIVITY IN THE WESTERN 3
ZONES LATE IN THE AFTERNOON AND THIS EVENING WITH TUNDERSTORMS
RESTRICTED TO THE KUSKOKWIM..AHKLUN AND KILBUCK MOUNTAINS IN ADDTION
TO THE ALASKA RANGE.

THE GOES IR IMAGRY SHOWS A BREAK TO THE NORTH OVER THE CENTRAL
INTEIOR AND A PRETTY ACTIVE BOUNDARY WITH DECENT THRMAL GRADIENT
ALONG THE BROOKS RANGE TO UPPER YUKON VALLEY. MODELS SUGGEST MORE
RETROGRESION OF THE BERING RIDGE WHICH BUILDS NW OVER THE RUSSIAN FAR
EAST BY THU AFTERNOON. AS A RESULT OF AGEOSTROPHIC FLOW THE TROF THAT
DIGS DOWN FROM THE ARCTIC COAST WILL DIG MORE SOUTHWEST ALONG THE
YUKON AND NOT GET AS FAR SOUTH AS YESTERDAYS FORECAST. BY 10AM FRIDAY
THE EASTERN BERING RIDGE IS REPLACERD WITH A TROF AND WEAK SOUTHWEST
FLOW ALONG THE KUSKOKWIM RIVER AND A VERY WEAK UPPER HIGH FROM
BRISTOL BAY TO THE COPPER RIVER BASIN. THERE WILL BE ENUF LEFT OVER
MOISTURE FOR THUNDERSTORM AND SHOWER ACTIVITY ALONG AND EITHER SIDE
OF THE ALASKA RANGE ON FRIDAY AND PROBABLY SATURDAY AS WELL WHILE
ZONE 141 MAY BE DRY.

MID RANGE MAP HAS THE ALEUTIAN LOW REMAINING IN THE ALEUTIANS AND A
WEAK UPPER CICULATION PERSISTING OVER THE NORTHEAST PACIFIC. THIS
LEAVES THE MAINLAND AREAS AND KODIAK ISLAND UNDER AN AREA OF UPPER
LEVEL HIGH PRESSURE. THE THREAT OF SHOWERS WILL TAPPER OFF SAT NIGHT
AND IM GOING TO BE VERY OPTIMISTIC IN THE FORECAST FOR THE 2ND HALF
OF THE WEEKEND. SO ASIDE FROM THE CLOUDY..RAINY..FOGGY KIND OF
FORECAST FOR THE ALUTNS AND BERING SEA OTHER AREAS WILL BE PRETTY
NICE WITH SOME GOOD SUNSHINE AND SEASONALBLE SUMMER TEMPERATURES
SUNDAY..MONDAY AND POSSIBLY ALITTLE LONGER. THEN SOME OF WHATS OUT IN
THE ALEUTIANS MAY COME IN AND GET THE WESTERN ZONES WITH AN INCREASE
IN CLOUDS AND A GREATER THREAT OF SHOWERS WHILE EASTERN ZONES STAY
PRETTY NICE. THATS ALL JUST A LONG SHOT AT THIS POINT AND WE WILL
KNOW MORE TOMORROW.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALES FOR THE PRIBS AND ERN ALUTNS SHOULD END BY THIS
EVENING
FIRE WEATHER...NONE

PERCY JUL 06