Small Craft Advisory 434, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
205 PM AKDT FRI JUN 24 2011

.ANALYSIS AND UPPER LEVELS...
THE PATTERN IS GETTING A LITTLE MORE ACTIVE TODAY AS A FEW SYSTEMS
ARE POISED TO IMPACT DIFFERENT AREAS OF THE STATE. THE LARGE BROAD
TROUGH THAT HAS BEEN NEARLY STATIONARY OVER THE EASTERN BERING AND
WESTERN INTERIOR HAS LOST MOST OF ITS ENERGY AS A SYSTEM RAPIDLY
DEVELOPS SOUTH OF THE WESTERN ALEUTIANS. A WEST TO EAST ORIENTED 150
KT JET WILL DIG OVER THE NEXT 24 HOURS HELPING TO DEVELOP A 970 MB
ALEUTIAN LOW.

AT THE BASE OF THE OLD TROUGH IS A VERTICALLY STACKED LOW THAT IS
SWINGING NORTHEAST. THIS MOVEMENT IS HELPING A VIGOROUS SHORTWAVE GET
EJECTED FROM THE PANHANDLE TOWARD SOUTHCENTRAL THIS EVENING.

.MODEL DISCUSSION...AFTER DAYS OF SPECULATION IT SEEMS THAT THE
PICTURE IS BECOMING MORE CLEAR FOR THIS EVENINGS FORECAST CHALLENGES.
MODELS INITIALIZE WELL AND ARE IN RELATIVELY GOOD AGREEMENT THROUGH
THE SHORT TERM. FOCUS WILL BE ON THE TWO SYSTEMS IMPACTING THE FAR
EAST AND WESTERN PORTIONS OF OUR DOMAIN TODAY WITH NO CHANGES MADE TO
THE MID AND LONG RANGE FORECAST.

.SHORT TERM FORECAST...
EASTERLY WAVE SPREADING CLOUDS RAPIDLY OVER SOUTHCENTRAL TODAY. IT
APPEARS THE WETTER NAM SOLUTION FROM A FEW DAYS AGO WILL PAN OUT WITH
RAIN EXPECTED IN MOST AREAS OVERNIGHT. INITIALLY WILL HAVE TO WATCH
FOR ISOLATED TO SCATTERED THUNDERSTORMS OVER THE NORTHEASTERN COPPER
RIVER BASIN AND NORTHERN SUSITNA VALLEY WHERE CLEAR SKIES PREVAILED
THIS MORNING ALLOWING MAXIMUM HEATING. SURFACE TEMPERATURES IN THIS
REGION ARE RANGING FROM 8 TO 14 DEGREES WARMER THAN THIS TIME
YESTERDAY.

A FEW SHOWERS MAY DEVELOP OVER THE MOUNTAINS LATE THIS AFTERNOON BUT
THEN RAIN SPREAD OVER THE REGION BY MIDNIGHT. THE WAVE QUICKLY MOVES
INLAND BUT CLOUDS AND MOISTURE REMAIN OVER THE REGION THROUGH THE DAY
SATURDAY...LEADING TO PARTLY SUNNY SKIES AND SCATTERED SHOWERS.

THE END OF THE WEEKEND AND EARLY NEXT WEEK WILL SEE PERIODS OF CLOUDS
AND SUN WITH MOISTURE STICKING AROUND. IT WILL BE VERY DIFFICULT TO
TIME INDIVIDUAL WAVES ROTATING AROUND THE LARGE TROUGH THAT IS
DEVELOPING IN THE BERING SEA...SO WILL HAVE TO STICK WITH SCATTERED
SHOWERS DURING THIS TIME FRAME.

.SOUTHWEST...CLOUDS AND AREAS OF LIGHT RAIN CONTINUE ALONG THE COAST
WHILE THE INTERIOR SEES SOME SUNNY BREAKS. SIMILAR TO THE EASTERN
DOMAIN...THE INTERIOR PORTIONS THAT ARE SEEING SUN THIS MORNING HAVE
THE GREATEST POTENTIAL TO SEE ISOLATED TO SCATTERED THUNDERSTORMS
THIS AFTERNOON/EVENING. CUMULUS ARE JUST NOW DEVELOPING ALONG THE
KUSKOKWIM RANGE SO WILL HAVE TO WATCH CAREFULLY FOR FURTHER
ENHANCEMENT FROM THE APPROACHING WAVE. SATURDAY AFTERNOON/EVENING
ALSO LOOK PROMISING FOR THUNDERSTORM POTENTIAL WITH ANOTHER
SOUTHEASTERLY SHORTWAVE CROSSING THE AREA WHILE THETA-E REMAINS
ELEVATED ACROSS THE REGION. COASTAL SECTIONS SHOULD REMAIN CLOUDY AND
COOL DURING THE WEEKEND AND EARLY NEXT WEEK.

FURTHER WEST...ALL EYES OUT WEST ON A RELATIVELY STRONG SUMMER SYSTEM
DEVELOPING SOUTH OF THE ALEUTIANS. MODELS HAVE DIALED INTO A
CONSENSUS OF ABOUT 972 MB SATURDAY MORNING AND MAXIMUM GALES AS THE
LOW APPROACHES THE WESTERN ALEUTIANS. THIS IS ALL DUE TO A 150 KT JET
DIVING SOUTHWARD AND PICKING UP QUITE A BIT OF MOISTURE AND ENERGY
FROM THE NORTHWEST PACIFIC. BEGINNING LATE SATURDAY MORNING...THE LOW
WILL BEGIN TO FILL AS IT MOVES TOWARD THE CENTRAL BERING SEA EARLY
NEXT WEEK. THE ASSOCIATED FRONTAL BOUNDARY WILL MARCH ACROSS THE
ALEUTIANS TOWARD SOUTHWEST ALASKA BUT LOSE MUCH OF ITS ENERGY ALONG
THE WAY. THE LARGE LOW STAYS IN THE CENTRAL AND EASTERN BERING SEA
THROUGH EARLY NEXT WEEK WHILE A WEAK RIDGE BUILDS OVER THE FAR
WESTERN BERING.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE 170 172 175 176 411 412 413 414.
FIRE WEATHER...NONE.

AB JUN 11