Gale Warning 124, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
1100 AM ADT FRI MAR 21 2008

.SYNOPSIS...
.SHORT RANGE...CYCLONIC INTERACTION CONTINUES ACROSS THE GULF OF
ALASKA AS THE INCOMING STRONG LOW IN THE SOUTH CENTRAL GULF
MARCHING NORTHEAST AND PUSHING THE OLD LOW IN THE NORTH CENTRAL
GULF TO SOUTH OF KENAI PENINSULA. OVER THE EASTERN AND
SOUTHEASTERN PERIPHERIES OF THE OLD LOW...QUITE COLD AIR ALOFT IS
ADVECTING AND CONCENTRATED MOISTURE WITH INCREASING PRECIPITATION
DRIFTING SLOWLY NORTHWARD ACROSS THE ALASKAN PANHANDLE. MOST
STATIONS REPORTED SNOW THROUGH MID MORNING WITH SNOW/RAIN MIX
JUST GET STARTED AS OF THIS WRITING. IN BETWEEN THE TRAILING AND
LEADING EDGES OF THE FRONTAL BOUNDARIES...WINDS HAVE PICKED UP
OVER THE SOUTHERN ZONES AND SLOWLY SPREADING NORTHWARD. MODELS
ARE IN GENERAL AGREEMENT WITH THE CYCLONIC INTERACTION AND TO
KEEP THE CONSISTENCY...WILL USE THE GFS SOLUTION FOR THE
AFTERNOON PACKAGE.

AS THE INCOMING LOW IS FORECAST TO DRIFT NORTH THROUGH SATURDAY
MORNING WITH A SECONDARY LOW FORMING JUST WEST OF THE QUEEN
CHARLOTTES...WINDS WILL DRAMATICALLY INCREASE OVER THE SOUTHERN
ZONES BY LATE SATURDAY AFTERNOON. AT THIS TIME...IT LOOKS LIKE TO
REACH A MARGINAL STORM FORCE DURING THE SATURDAY EVENING HOURS
AND CONTINUES TO ENHANCE THROUGH THE NIGHT TIME. FOR THE
AFTERNOON FORECAST PACKAGE...WILL KEEP THE WIND ADVISORY PAVING
ENTIRE ZONES FOR TONIGHT WITH GALE WARNING FOR MOST MARINE ZONES.
FOR SATURDAY...WIND ADVISORY SHOULD CONTINUE ACROSS THE SOUTHERN
ZONES WITH GALE FOR SOUTHERN MOST OUTSIDE WATERS AND CLARENCE
STRAIT. THIS WIND WILL SPREAD NORTH DURING THE AFTERNOON HOURS TO
INCLUDE PETERSBURG/WRANGELL ZONE WITH GALE FOR SOUTHERN THREE
OUTSIDE WATERS...SOUTHERN INNER CHANNELS AND CROSS SOUND.

.LONG RANGE...NOT MUCH CHANGE IN SYNOPTIC THINKING WITH A MEAN
COLD UPPER LEVEL LOW CENTERED JUST EAST OF KODIAK DUMBBELLING A
SERIES OF SMALL BUT POTENT LOWS NORTHWARD THROUGH THE EASTERN
GULF. DO HAVE MINOR TIMING AND POSITIONAL DIFFERENCES WITH LOW
MOVING NORTH SAT-SAT NIGHT. HAVE OPTED TO BLEND NEW GFS40 WITH
OLD GRIDS THROUGH MONDAY. BEYOND MONDAY SPREAD IS LARGER TODAY
AND WILL NOT MAKE ANY CHANGES TO LONGER RANGE PERIODS.

EXPECT A DEVELOPING LOW TO TRACK NORTH INTO THE SOUTHEAST GULF
SATURDAY AFTERNOON AND DEEPEN 10 TO 15 MB AS IT CURVES NW ALONG
THE OUTER COAST SATURDAY NIGHT. MODELS HAVE BEEN CONSISTENTLY
ADVERTISING A SE 70 KT 85H JET THAT MOVES ACROSS SOUTHEAST ALASKA
DURING THIS TIME AND EXPECT A PERIOD OF VERY WINDY CONDITIONS TO
SPREAD THROUGH THE INNER CHANNELS AND WILL ISSUE WIND ADVISORY
THROUGH SATURDAY EVENING FOR SOUTHERN HALF. WILL CONTINUE GALE TO
STORM FORCE WINDS FOR COASTAL WATERS AND SOUTHERN INNER CHANNELS
SATURDAY EVENING. THE ASSOCIATED OCCLUSION WILL PUSH INTO
SOUTHERN ZONES SATURDAY EVENING AND BE  ACROSS NORTH CENTRAL
SUNDAY MORNING. THERE IS A SMALL PUSH OF WARM AIR AHEAD OF THE
FRONT SO THINK PRECIP WILL QUICKLY GO OVER TO RAIN ALL AREAS. A
MODEST PUSH OF COLD AIR BEHIND THE FRONT...85H TEMPS DROP TO
-10C...WILL SPREAD ACROSS THE PANHANDLE FROM THE SOUTHWEST ON
SUNDAY WHICH IS EXPECTED TO TURN RAIN OVER TO SNOW SHOWERS BEFORE
TAPERING OFF IN THE AFTERNOON.

A SECOND SLIGHTLY WEAKER SYSTEM FOLLOWS A SLIGHTLY MORE WESTERLY
TRACK SUNDAY NIGHT INTO MONDAY. STILL EXPECT GALES ALONG THE
OUTER COAST SUNDAY NIGHT BUT ONLY MAX SMCR FOR INNER CHANNELS
WITH THIS. A THIRD EVEN WEAKER SYSTEM FOLLOWS NORTH ON TUESDAY
WITH OVERALL PRESSURE GRADIENTS GREATLY DIMINISHED AND ONLY
LIMITED IMPACT FOR INNER CHANNELS.

ON TUESDAY PATTERN BEGINS TO CHANGE AS UPPER LOW NEAR KODIAK
OPENS UP INTO A TROUGH AND SLIDES EAST THROUGH THURSDAY WITH A
MORE ZONAL PATTERN ACROSS THE GULF.

.AJK...WATCHES/WARNINGS/ADVISORIES
PUBLIC...WND ADV FOR ENTIRE ZNS,
MARINE...GALE WRNG FOR PKZ011>013-021-022-034-036-041>043-051
         -052-310,
      ...SCA FOR REST OF CSTL WTRS.

AHN/MM