Small Craft Advisory 522, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
145 PM AKDT WED JUL 1 2009

.MODEL DISCUSSION...
MODELS ARE IN GOOD AGREEMENT THROUGH FRIDAY...WHEN SIGNIFICANT
DIFFERENCES IN SOLUTIONS BEGIN TO EXIST. LARGEST DISAGREEMENTS ARISE
OVER THE STRENGTH AND POSITION OF A LOW IN THE BERING SEA...THERE
REMAINS LITTLE CONSISTENCY IN THE SOLUTIONS....FROM BOTH THE GFS AND
THE EUROPEAN...SO CONFIDENCE IS LOW IN THE LONG TERM FORECAST FOR THE
BERING AND ALEUTIANS.

.ANALYSIS AND UPPER LEVELS...
A HIGHLY AMPLIFIED PATTERN CONTINUES ACROSS SOUTHERN ALASKA. A VERY
LARGE UPPER LEVEL TROUGH EXPANDS FROM RUSSIA INTO THE PACIFIC WITH AN
UPPER LEVEL RIDGE BUILDING IN ACROSS SOUTH CENTRAL ALASKA. A
VERTICALLY STACKED SURFACE LOW IS LOCATED IN THE CENTRAL BERING WHICH
CONTINUES TO MOVE VERY SLOWLY.

.SHORT TERM FORECAST...
ACROSS SOUTH CENTRAL ALASKA A QUIET DAY IS IN STORE. RIDGE CONTINUES
TO BUILD IN  ACROSS THE REGION RESULTING IN SUBSIDENCE AND CALM
WEATHER. SUNNY SKIES WILL BE COMMON UNTIL EARLY AFTERNOON WITH HAZE
BEING COMMON DUE TO SINKING MOTION UNDER THE RIDGE AND WARM SURFACE
TEMPERATURES. 12Z SOUNDING SHOWS VERY WARM 850MB TEMPS...AROUND 7
DEGREES C... WHICH SHOULD INHIBIT MOST THUNDERSTORM DEVELOPMENT.
THERE WILL STILL BE SOME SCATTERED TERRAIN INDUCED THUNDERSTORMS
AROUND THE MOUNTAINS BUT DUE TO WEAK UPPER LEVEL FLOW THUNDERSTORM
MOVEMENT WILL BE VERY SLOW.

SOME LOW CLOUDS AND FOG CONTINUE TO MOVE JUST OFFSHORE FROM PRINCE
WILLIAM SOUND TOWARDS THE KENAI PENINSULA. WHILE THESE CLOUDS HAVE
REMAINED OFFSHORE SO FAR TODAY...AM CONCERNED WITH THE LATEST
SATELLITE IMAGES SHOWING FOG MOVING NORTH UP COOK INLET. WILL
CONTINUE TO MONITOR THESE LOW CLOUDS AND FOG AND UPDATE AS NEEDED.

WEST ACROSS THE BERING AND ALEUTIANS VERTICALLY STACKED LOW
CONTINUES TO MOVE VERY SLOWLY. THIS SURFACE LOW WILL CONTINUE TO
WEAKEN BUT THE UPPER LEVEL TROUGH REMAINS. BY THEN END OF THE WORK
WEEK IT APPEARS THAT ANOTHER SURFACE LOW WILL MOVE TOWARDS THE
ALEUTIANS...INCREASING WIND AND CHANCES FOR PRECIP. STARTING TODAY IT
APPEARS THAT GALE FORCE WINDS WILL OCCUR OVER THE BERING SEA AND
CENTRAL ALEUTIANS.

.LONG TERM FORECAST...
BEYOND FRIDAY THE CONFIDENCE OF PLACEMENT AND STRENGTH OF THE BERING
LOW BECOMES VERY LOW. MODELS HAVE HAD VERY LITTLE RUN TO RUN
CONSISTENCY WITH THIS FEATURE. A COLD FRONT WILL TRAIL THIS LOW AND
STALL OUT ACROSS THE BRISTOL BAY AREA BY FRIDAY. DEPENDING ON HOW THE
LOW EVOLVES AND MOVES WILL DETERMINE HOW FAR EAST AND HOW STRONG THIS
FRONT WILL BE BUT AT CURRENT TIME BELIEVE IT WILL REMAIN NEARLY
STATIONARY OVER BRISTOL BAY. IT APPEARS BY THE WEEKEND A SHORT WAVE
TROUGH WILL MOVE INTO SOUTH CENTRAL ALASKA WHICH COULD BRING SOME
SHOWERS TO THE REGION FOR THE FOURTH OF JULY HOLIDAY.

.FIRE WEATHER...
YESTERDAY CAME CLOSE TO 30 PERCENT RH CRITERIA IN ZONE 161. TODAY
WILL ONCE AGAIN BE A CLOSE CALL...BUT NOT CONFIDENT ENOUGH TO ISSUE
ANY FIRE WEATHER HEADLINES AT THIS TIME.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE
MARINE...GALE WARNING 170 172 185 180 165
FIRE WEATHER...NONE

TARALDSEN JUL 09