Small Craft Advisory 268, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
414 PM AKDT FRI APR 1 2011

.SHORT TERM...UPPER LEVEL TROUGH OVER THE NORTHERN PANHANDLE
WILL CONTINUE TO MOVE EAST ACROSS SOUTHEAST ALASKA THROUGH THIS
EVENING AND WILL BE SOUTHEAST OF THE AREA BY SATURDAY MORNING. AN
UPPER LEVEL RIDGE BUILDING INTO THE GULF TODAY WILL SHIFT EAST
OVER THE PANHANDLE SATURDAY.

 RADAR SHOWING THERE ARE STILL QUITE A FEW SHOWERS MOVING ONSHORE
IN WESTERLY FLOW ALTHOUGH THEY ARE BECOMING LESS ORGANIZED AND
STARTING TO THIN OUT. EXPECT THIS TRENDS TO CONTINUE THROUGH THE
AFTERNOON AND EVENING AS THE UPPER TROUGH MOVES THROUGH AND
SHOWERS WILL END IN ALL BUT THE FAR NORTH BY MORNING. RESIDUAL
LOW LEVEL MOISTURE TRAPPED ACROSS NORTHERN INNER CHANNELS WILL
KEEP SOME "DRIZZLE SHOWERS" AND MIST OVER THIS AREA UNTIL EARLY
SATURDAY. ALSO STILL HAVE WEAK CAA AND COULD SEE PRECIP MIX WITH
SNOW THIS EVENING BUT NO ACCUMULATIONS EXPECTED. EXPECT LOW
TEMPERATURES NEAR TO SLIGHTLY ABOVE FREEZING FOR MOST LOCATIONS
TONIGHT.

 AS THE RIDGE MOVES OVER SOUTHEAST ALASKA SATURDAY EXPECT CLOUDS
TO DECREASE WITH SOUTHERN ZONES BECOMING PARTLY CLOUDY IN THE
AFTERNOON BUT PROBABLY STAYING MOSTLY CLOUDY IN THE NORTH. THIS
WILL ALLOW HIGH TEMPERATURES TO CREEP UP INTO THE UPPER 40S FOR
SOUTHERN ZONES.

 MODELS IN GOOD AGREEMENT THROUGH THE SHORT TERM. UPDATED WINDS
AND PRES WITH NAM OTHERWISE MADE LITTLE IN THE WAY OF CHANGES.

&&

.LONG TERM...MODELS ARE IN FAIR AGREEMENT WITH THE STRONG FRONT
THAT MOVES TO THE SOUTHEAST ALASKA COASTAL WATERS EARLY SUNDAY AND
THROUGH THE PANHANDLE SUNDAY NIGHT. STRONG GALES ARE EXPECTED
WITH THE FRONT OVER THE OUTER COAST...CROSS SOUND...AND CLARENCE
STRAIT. RAIN WILL SPREAD OVER SOUTHEAST AND THE EASTERN GULF COAST
ON SUNDAY.

THE PARENT SURFACE LOW ASSOCIATED WITH THE FRONT CROSSES THE GULF
OF ALASKA ON MONDAY BUT THE ENSEMBLE SPREAD BEGINS TO GROW WITH
THIS SYSTEM AS MODELS VARY ON THE TRACK AND AMOUNT OF WEAKENING.
GFS IS A LITTLE SLOWER WEAKENING THE LOW WHICH SEEMS REASONABLE
GIVEN THE COLD AIR AVAILABLE TO IT...BUT HPC FAVORED MORE OF AN EC
SOLUTION BECAUSE OTHER MODELS ALSO SEEM TO BE FOLLOWING ITS LEAD.
THE FINAL HPC FORECAST WAS ACTUALLY SOMEWHAT OF A COMPROMISE
BETWEEN THE TWO MODELS.

WITH A DYING LOW TO THE SOUTH AND COOLER UNSTABLE AIR OVER THE
EASTERN GULF SCATTERED CONVECTION WILL LIKELY CONTINUE OVER THE
PANHANDLE THROUGH WEDNESDAY. THE NEXT FRONT CROSSING THE GULF IS
EXPECTED TO REACH SOUTHEAST ALASKA LATE THURSDAY HOWEVER THERE IS
A SIGNIFICANTLY LARGE ENSEMBLE SPREAD WITH THE PARENT LOW THAT IS
PROJECTED TO MOVE INTO THE WESTERN GULF LATE IN THE WEEK. FOR THIS
REASON THERE IS STILL CONSIDERABLE UNCERTAINTY WITH THE TIMING AND
STRENGTH OF THE FRONT.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...SMALL CRAFT ADVISORY FOR PKZ012.
         SMALL CRAFT ADVISORY DUE TO SEAS FOR PKZ041>043-051-052.

&&

MM/CFD