Small Craft Advisory 462, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
115 PM ADT THU MAY 24 2007

.MODEL DISCUSSION...NCEP/UKMET MODEL SYNOPTIC MSLP SCALE
INITIALIZATIONS AND FORECAST TRENDS ARE IN GOOD AGREEMENT. THE GFS
STILL APPEARS TO BE UNCERTAIN ON THE INTENSITY OF A DEVELOPING LOW
WHICH MOVES SOUTH OF THE WESTERN ALEUTIANS MON. CURRENT RUN IS ABOUT
11 MB DEEPER THAN PREVIOUS 00Z RUN. GFS OPERATIONAL SOLUTION APPEARS
TO BE BASED ON ONE ENSEMBLE MEMBER(OUT-LIER) RATHER THEN THE MEAN.
BASED ON THIS...WILL JUST NUDGE CURRENT WIND GRIDS TOWARD THE LATEST
RUN...RATHER THAN MAKE A MAJOR CHANGE.

.ANALYSIS AND UPPER LEVELS...OVERLAY OF 850-500 MB RH AND WATER VAPOR
IMAGERY FROM GFS40 SHOWS GOOD CORRELATION THROUGH 18Z TODAY. FORECAST
TREND IS TO TAKE OLD CENTER SOUTH OF SAND AND MOVE IT INTO THE
EASTERN BERING SEA SAT. TROUGH OVER THE GULF PIVOTS NORTH AND BY SAT
EXTENDS EAST FROM CENTER OVER THE EASTERN BERING SEA TO SOUTHEAST
ALASKA. TO WEST...TROUGH EXTENDS EAST TO THE PRIBILOFS. HIGH PRESSURE
RIDGE BUILDS NORTH OF WEST-EAST TROUGH AXIS.

.SURFACE...
.EAST...A GENERALLY CLOUDY AND MOIST PATTERN WILL HOLD THROUGH SUN.
MAIN AREAS OF RAIN WILL BE ALONG COASTAL LOCATIONS AND PORTIONS OF
SOUTHCENTRAL ALASKA. THE COPPER RIVER BASIN WILL GENERALLY BE ON THE
DRY SIDE. IMPULSE MOVING THROUGH SOUTHCENTRAL THIS AFTERNOON MOVES
NORTH OF THE AREA THIS EVENING. FRONTAL ZONE EXTENDING FROM NEAR
KODIAK ISLAND TO THE SE GULF MOVES NORTH AND STALLS OVER THE NORTHERN
GULF AS RIDGE HOLDS OVER THE NORTH GULF/SOUTHERN MAINLAND. RAIN WITH
FRONT MOVES NORTH TONIGHT...AND WILL LIKELY BE CONFINED MAINLY TO
COASTAL LOCALS AND EAST EXPOSURES OVER SOUTHCENTRAL. EXPECT MAX SMALL
CRAFT/MIN GALES IN NORTH GULF COAST THIS AFTERNOON AND TONIGHT AHEAD
OF FRONTAL TROUGH. COMBO RIDGE ALONG THE NORTH GULF AND WEAK THERMAL
TROUGH OVER THE MAINLAND WILL PRODUCE GUSTY GAP WINDS OVER SOUTHERN
ALASKA..TURNAGAIN ARM/KNIK...THROUGH TODAY AND FRI. ALSO EXPECT GUSTY
SOUTH WINDS DURING THE AFTERNOON AND EVENING HOURS ALONG THE COPPER
RIVER TODAY AND FRI...AND TO LESSER EXTENT SAT.

PROBABLY WILL SOME DRIER WEATHER SUN NIGHT/MON AS RIDGE TAKES HOLD
OVER AREA...ALTHOUGH A FEW SHOWERS STILL POSSIBLE. RESURGENCE OF
MOISTURE AGAIN AND SPREADING TO KODIAK ISLAND MON AND TO THE MAINLAND
TUE WITH APPROACH OF DEVELOPING NE PACIFIC LOW CENTER.

.WEST...EXPECT GENERALLY CLOUDY CONDITIONS LIKELY TO HOLD OVER THE SW
MAINLAND THROUGH THE WEEKEND. BEST SHOT AT LIGHT RAIN OR SHOWERS WILL
BE OVER THE DELTA/BRISTOL BAY AS LOW CENTER SOUTH OF AK PEN BECOMES
STATIONARY EAST OF THE PRIBILOFS. EXPECT RELATIVELY DRY CONDITIONS
OVER THE KUSKOKWIM VALLEY WITH SE DOWNSLOPE TODAY AND FRI. MAY SEE
INCREASE IN SHOWER ACTIVITY OVER THE KUSKOKWIM VALLEY SAT AND SUN AS
SE DOWNSLOPE WEAKENS. BRISK NORTHERLY FLOW OVER THE EASTERN ALEUTIANS
AND PRIBILOFS WILL WEAKEN FRI NIGHT AND SAT. HIGH PRESSURE HOLDS OVER
THE WESTERN ALEUTIANS THROUGH SAT. DEVELOPING NORTH PACIFIC CENTER
MOVES SOUTH OF WESTERN ALEUTIANS FRI. CURRENT RUN WOULD INDICATE
GALES NORTH OF CENTER...BUT WILL HOLD A LITTLE WEAKER BASED ON
ENSEMBLE GUIDANCE.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE 130 AND 138.
FIRE WEATHER...NONE.

RMC MAY 07