Small Craft Advisory 683, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
300 PM AKDT TUE SEP 9 2008

.MODEL DISCUSSION...
MODELS INITIALIZE WELL BUT BEGIN DIVERGING ON SOLUTIONS IN THE FIRST
48 HOURS. THERE ARE SOME MINOR DIFFERENCES REGARDING THE DEVELOPING
TRIPLE POINT LOW IN THE NORTHWESTERN GULF LATER TONIGHT AND SOME MORE
SIGNIFICANT TIMING AND STRENGTH DIFFERENCES WITH A FRONTAL SYSTEM
DEVELOPING NEAR THE WESTERN ALEUTIANS. THE 12Z GFS IS SHOWING SOME
MORE CONSISTENCY OUT WEST AND IS THE A GOOD MIDDLE OF THE ROAD
CHOICE. NO CHANGES WERE MADE BEYOND 60 HOURS.

.ANALYSIS AND UPPER LEVELS...
THE LOWEST PRESSURE READING EARLY THIS AFTERNOON IS AT KING SALMON AT
995 MB. BY SATELLITE IMAGERY AND SURROUNDING OBSERVATIONS...IT IS
APPARENT THE LOW IS JUST WEST OF KING SALMON OVER BRISTOL BAY. A
TRIPLE POINT LOW IS DEVELOPING SOUTHEAST OF KODIAK AND WILL MOVE
NORTHWARD QUICKLY OVER THE SOUTHERN PENINSULA TONIGHT. A LONG WAVE
NEUTRALLY TILTED TROUGH REMAINS ENTRENCHED OVER THE EASTERN BERING
SEA AND OVER THE NORTH PACIFIC. TO THE WEST...A FRONTAL BOUNDARY AND
ASSOCIATED LOW PRESSURE SYSTEM ARE APPROACHING THE WESTERN ALEUTIANS.

.SHORT TERM FORECAST...
SOUTH CENTRAL...WARM FRONT PASSAGE OCCURRED ACROSS SOUTH CENTRAL
ALASKA EARLY THIS MORNING. BEHIND THE FRONT WAS A SHORT CLEARING
BEFORE CONVECTIVE PRECIPITATION BEGAN AGAIN. THE SHOWERY WEATHER WILL
CONTINUE THROUGH THE EVENING BEFORE THE AFFECTS OF THE TRIPLE POINT
LOW LATER TONIGHT...BECOMING MORE OF A STEADY RAIN THROUGHOUT THE
AREA. WHILE UPSLOPE AREAS WILL SEE MODERATE TO HEAVY RAIN AT
TIMES...IT APPEARS THE BEST FETCH OF SUBTROPICAL MOISTURE HAS SHIFTED
TO THE EAST FROM EASTERN PRINCE WILLIAM SOUND TO JUNEAUS AOR. WILL
AGAIN BE CONSIDERING A FLOOD WATCH FOR THE AREAS SURROUND PRINCE
WILLIAM SOUND AS CREEKS ARE RUNNING HIGH AND THE GROUND IS SATURATED.

WINDS THROUGH PORTAGE VALLEY AND TURNAGAIN ARM HAVE REMAINED VERY
STRONG TODAY. THE PRESSURE GRADIENT SHOULD BE AT ITS PEAK EARLY THIS
AFTERNOON AS WE EXPECT WINDS TO GRADUALLY DIMINISH OVERNIGHT AS THE
LOW MOVES INLAND.

BEYOND ANOTHER RAINY DAY TUESDAY...EXPECTING MORE CLOUDS AND
SCATTERED SHOWERS ON THE BACKSIDE OF THIS SYSTEM.

WEST OF THE ALASKA RANGE...
THE STACKED LOW OVER BRISTOL BAY IS PROVIDING PLENTY OF CLOUDS AND
SHOWERS TO THE SOUTHWEST MAINLAND. A SLOW TRANSITION FROM ONE UPPER
LOW TO THE NEXT WILL PROVIDE A BREAK AND SOME FAIR WEATHER LATER IN
THE WEEK. PATCHY FOG AND MOSTLY CLOUDY WITH SCATTERED SHOWERS WILL
CONTINUE TO BE THE BEST FORECAST FOR THE NEXT SEVERAL DAYS.

BERING SEA AND ALEUTIANS...
WIDESPREAD FOG PERSISTS UNDER HIGH PRESSURE IN THE CENTRAL AND
WESTERN ALEUTIANS. AS MENTIONED IN THE MODEL DISCUSSION...THERE IS
SOME DISAGREEMENT WITH THE PATH OF THE LOW DEVELOPING WEST OF THE
ALEUTIANS. WHILE THE PATTERN CHANGE SEEMS INEVITABLE WITH A LOW
DEVELOPING WEST OF THE ALEUTIANS AND MOVING TOWARD THE ALASKA
PENINSULA...THE TIMING OF THIS CHANGE REMAINS UNCERTAIN.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALES 120 125 175 176.
FIRE WEATHER...NONE.

AB SEP 08