Small Craft Advisory 642, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 AM ADT TUE AUG 7 2007

.MODEL DISCUSSION...
THE MODELS SEEM TO HAVE RESOLVED THEIR DIFFERENCES FROM YESTERDAYS
12Z PACKAGE AND ARE IN GOOD AGREEMENT THIS MORNING.  YESTERDAYS 12Z
RUN OF THE GFS APPEARS TO BE AN OUTLIER BUT THE GFS HAS COME BACK
INTO LINE WITH THE REST OF THE MODELS AND CONFIDENCE IS HIGHER TODAY.

.ANALYSIS AND UPPER LEVELS...
THE LONGWAVE RIDGE HAS BECOME THE MAIN FEATURE IN THE REGION THIS
MORNING.  THE STACKED LOW OVER THE KAMCHATKA PENINSULA IS NOT
EXPECTED TO MOVE MUCH IN THE SHORT TERM BUT IT WEAKENS THE RIDGE WILL
SHIFT EASTWARD OVER THE MAINLAND AND IMPROVE THE WEATHER THERE.  BY
THE WEEKEND THE REMAINDER OF THE FRONT ASSOCIATED WITH THIS LOW WILL
MOVE THROUGH THE RIDGE AS A SHORTWAVE AND BRING SHOWERS TO THE
MAINLAND.

.SHORT TERM FORECAST...
EAST OF THE ALASKA RANGE...SHOWERS WILL CONTINUE TODAY ESPECIALLY IN
THE EASTERN SIDE OF THE ZONE.  A LOW LEVEL JET ALOFT WILL CONTINUE TO
CAUSE GUSTY WINDS IN THE SOUTHCENTRAL REGION BUT THESE WILL TAPER OFF
IN THE AFTERNOON AS THE LOW AND THE JET MOVE EASTWARD. BY TOMORROW
THE SKIES WILL BE CLEARING AND THE EASTERN ZONES CAN EXPECT GOOD
WEATHER THROUGH SATURDAY.

WESTERN MAINLAND...THE RIDGE WILL CONTINUE TO AFFECT THE WESTERN
MAINLAND THROUGH FRIDAY.  LOW CLOUDS AND FOG ARE DRIFTING IN THIS
MORNING OFF THE BERING SEA OVER THE WEST COAST.  THIS WILL CONTINUE
OFF AND ON THROUGH THE PERIOD.

ALEUTIANS AND BERING...THE FRONT CURRENTLY MOVING THROUGH THE CENTRAL
ALEUTIANS WILL REMAIN IN THE AREA THROUGH WEDNESDAY. AS THE FRONT
WEAKENS THE WINDS WILL WEAKEN AS WELL.  BY THURSDAY THE TROUGH WILL
START TO PROGRESS EASTWARD AND BRING SMALL CRAFT WINDS TO THE EASTERN
ALEUTIANS.

.LONG TERM FORECAST...
BY THE WEEKEND THE RIDGE BECOMES MUCH MORE OF A DIRTY RIDGE AND
VARIOUS SHORTWAVES MOVE ACROSS.  THIS WILL BRING A RETURN OF RAINY
CONDITIONS TO THE MAINLAND...ESPECIALLY SINCE MOST AREAS WILL
EXPERIENCE SOUTHWEST FLOW.  IT LOOKS LIKE THIS IS THE BEGINNING OF A
TRANSITION IN THE PATTERN AS WELL TO A LONGWAVE TROUGH CENTERED OVER
THE BERING.  HOWEVER THAT IS FAR IN THE FUTURE SO PRETTY UNCERTAIN AT
THIS POINT.

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

LEWF AUG 07