Small Craft Advisory 401, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
530 AM ADT SUN APR 30 2006

.DISCUSSION...
PREVIOUS FORECAST DISCUSSIONS HIT NAIL ON HEAD REGARDING COLD UPPER
LOW OVER THE GULF OF ALASKA. MODELS PICKING UP ON LARGER SCALE
FEATURES BUT MISSING THE SMALL VORTICES ROTATING AROUND ITS
PERIPHERY. MODELS IN AGREEMENT THAT THE PARENT LOW WILL DISSIPATE
TODAY AS IT DRIFTS NORTHEAST TOWARD YAKUTAT. UNTIL THEN ADJUSTMENTS
IN THE FORECAST WILL BE NECESSARY IN TIMING SHOWERS ASSOCIATED WITH
THE ROGUE LOWS. OUT WEST ETA IS A BIT FAST ON THE EVOLUTION OF THE
LOW SOUTH OF ADAK. GFS AND UKMET IN BETTER AGREEMENT FOR THE FIRST 24
HOURS AND THEN ETA COMES INTO LINE AS A NEW LOW DEVELOPS ALONG THE
FRONTAL BOUNDARY SOUTH OF COLD BAY AND DRIFTS NORTH TOWARD THE AKPEN
BY WEDNESDAY. GFS WAS MODEL OF CHOICE FOR THIS FORECAST PACKAGE.

SOUTHCENTRAL SURFACE...TODAY SHOULD BE A REPEAT OF YESTERDAYS SHOWER
ACTIVITY WITH MAYBE A SLIGHT DECREASE IN COVERAGE. OTHERWISE MOSTLY
SUNNY SKIES IN THE MORNING WITH A FEW TOWERING CUES DEVELOPING BY
NOON EVOLVING INTO ISOLATED CBS AND SCATTERED SHOWERS BY LATE
AFTERNOON. MOST SHOWERS WILL REMAIN NEAR THE COAST AND THE INTERIOR
MOUNTAIN RANGES. VERY WEAK FLOW ALOFT WILL ALLOW SOME SHOWERS TO
DRIFT OVER THE VALLEYS BUT STILL DO NOT EXPECT LARGE SWATH OF SHOWER
ACTIVITY LIKE WE WILL SEE LATER IN THE SPRING AND EARLY SUMMER...AND
STILL NO MENTION OF THUNDER. FRONT WILL MOVE INTO THE NORTHERN GULF
TONIGHT. THE LATE NIGHT ARRIVAL OF MOISTURE MEANS MOST PRECIPITATION
COULD BEGIN AS SNOW IN PLACES LIKE KODIAK OVERNIGHT AND SEWARD AND
WHITTIER BY EARLY MONDAY MORNING. THERE IS NO SOURCE OF COLD AIR TO
BE DRAGGED DOWN SO SNOW WILL QUICKLY MIX WITH AND THEN CHANGE OVER TO
RAIN BY MID MORNING ON MONDAY. THE FRONT WILL BE STRONG ENOUGH TO
KEEP ANCHORAGE AND THE WESTERN KENAI DOWNSLOPED WHICH ALSO MEANS
STRONG WINDS THROUGH THE PORTAGE VALLEY AND TURNAGAIN ARM.

OUT WEST...RELATIVELY QUIET CONDITIONS OUT WEST WITH THE MAIN LOW AND
ASSOCIATED FRONTAL BOUNDARY LOCATED JUST SOUTH OF THE CENTRAL
ALEUTIANS. HIGH PRESSURE OVER BRISTOL BAY AND THE SOUTHWEST INTERIOR
WILL BE SHORTLIVED AS THE FRONT SWINGS NORTHWARD ACROSS THE AKPEN
MONDAY EVENING. IN THE MEAN TIME PATCHY FOG DEVELOPING EARLY THIS
MORNING AND BRISK NORTHERLY FLOW OVER THE BERING SEA CARRYING
ISOLATED SHOWERS.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALES 120 130 132 138 150 155 160 172 175.
FIRE WEATHER...NONE.

AB APR 06