Gale Warning 128, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
1130 AM ADT SAT MAR 22 2008

.SYNOPSIS...
.SHORT RANGE...A DYNAMIC HIGH ENERGY PATTERN WILL PERSIST ACROSS
THE EASTERN GULF AND SOUTHEAST ALASKA THROUGH SUNDAY MORNING AS A
COLD UPPER LEVEL LOW ACROSS THE WESTERN GULF DUMBBELLS A SERIES
OF RAPIDLY DEVELOPING SURFACE LOWS NORTH THROUGH THE EASTERN
GULF. THE LEAD OCCLUSION EXTENDING FROM JUST NORTH OF PAYA...
THROUGH GLACIER BAY...SOUTH ALONG CHATHAM STRAIT...AND SOUTHWEST
INTO THE NORTH PACIFIC WILL BECOME STATIONARY ACROSS SOUTH
CENTRAL SOUTHEAST ALASKA TODAY AS A DEVELOPING WAVE ALONG THE
FRONT NEAR 50/150 RAPIDLY DEEPENS AND MOVES NORTH INTO THE
SOUTHEAST GULF THIS EVENING. THE FRONT THEN PUSH NORTH THROUGH
SOUTHEAST ALASKA AS A WARM FRONT TONIGHT. THE COLD FRONT THEN
SWINGS NE THROUGH THE COASTAL AND SOUTHERN ZONES 09Z-15Z TONIGHT
AND THROUGH CENTRAL AND NORTHERN ZONES 15Z-21Z SUNDAY. WIND...
PHASE CHANGE...AND DEEP CONVECTION OVER NE GULF ARE MAIN CONCERNS
IN SHORT TERM.

ADVISORY LEVEL SE WINDS CURRENTLY OCCURRING ACROSS SOUTHERN ZONES
AHEAD OF LEAD OCCLUSION WITH BREEZY TO LOCALLY WINDY CONDITIONS
EXTENDING NORTH INTO CENTRAL AND COASTAL SOUTHEAST ALASKA. EXPECT
THIS WIND TO EASE A LITTLE THROUGH THE MORNING AND EARLY
AFTERNOON AS FRONT BECOMES STATIONARY AND DEVELOPING LOW TO SOUTH
ALTERS PRESSURE GRADIENT ORIENTATION. AS WAVE IN NORTH PACIFIC
DEEPENS 20 MB OVER NEXT 12 HOURS...A STRONG 80+ KT SSE 85H JET
DEVELOPS AS IT RACES NORTH THROUGH HECATE STRAIT AND SOUTHERN
PANHANDLE THROUGH THE LATE AFTERNOON AND EVENING. THIS WILL BRING
A SECOND SHOT OF SE WINDS THAT ARE EXPECTED TO REACH STORM FORCE
FOR CLARENCE STRAIT AND 80 MPH GUSTS TO SOUTHERN AND COASTAL
ZONES GENERALLY IN 3 PM TO MIDNIGHT TIME FRAME. THIS JETS WEAKENS
AS IT CROSSES CENTRAL PANHANDLE AND CURVES TO THE NORTHWEST LATER
TONIGHT AND WILL KEEP WINDS IN ADVISORY CATEGORY HERE. PAYA WILL
STAY NORTH OF LOW CENTER AND SHOULD SEE WINDS BACK NE TONIGHT AND
NOT SHIFT TO THE SOUTH UNTIL FRONT MOVES THROUGH SUNDAY MORNING.

EXPECT PRECIPITATION TO FALL MAINLY AS RAIN/RAIN SHOWERS ACROSS
SOUTHEAST ALASKA TODAY. BIORKA RADAR SHOWERS ONLY ISOLATED CELLS
BEHIND THE FRONT SO EMPHASIS OF RAIN WILL BE ACROSS SOUTHERN
HALF. MAIN EXCEPTION WILL BE PAYA-PAHN WHERE LEAD OCCLUSION HAS
MOVED THROUGH AND TEMPERATURES REMAIN COLD ENOUGH FOR SNOW
SHOWERS THROUGH TONIGHT. THESE AREAS COULD PICK UP A FEW QUICK
INCHES OF NEW SNOW WITH HEAVIER SHOWERS. ANOTHER POSSIBILITY WILL
BE ACROSS SOUTH CENTRAL AREAS JUST AHEAD OF WARM FRONT DUE TO
STRONG UVV AND HIGH PRECIPITATION RATES AND WILL MONITOR THIS
THROUGH THE DAY. BY LATE TONIGHT AND BEHIND THE COLD FRONT...WIND
DROPS OFF QUICKLY AND EXPECT RAIN TO CHANGE TO SNOW JUST BEFORE
ENDING WHICH WILL LIMIT ACCUMULATIONS TO INCH OR LESS. WILL GO
WITH A CHANCE OF MIXED SHOWERS AND A FEW SUN BREAKS SUNDAY
AFTERNOON.

THE NORTHERN GULF REMAINS QUITE UNSTABLE WITH LIGHTNING DETECTION
RECORDING A HALF DOZEN STRIKES JUST TO SW OF PAYA EARLY THIS
MORNING. MAIN CLUSTER OF SHOWERS IS WEST OF YAKUTAT AND FOR NOW
WILL KEEP MENTION OF THUNDERSTORMS IN COASTAL MARINE FORECASTS.

.LONG RANGE...MODELS CONTINUE TO BE IN FAIR AGREEMENT IN THE LONG
TERM. THE MOST CONSISTENT AND BEST INITIALIZED MODEL REMAINS THE
ECMWF. IT HAS GOOD SUPPORT FROM THE 00Z AND 06Z NAEFS ENSEMBLE
WITH THE HOLDING THE PATTERN CHANGE SOUTH OF THE ALEUTIANS TILL
LATER THIS WEEK. THE GFS ATTM CONTINUES TO BREAK DOWN THE
BLOCKING PATTERN NEAR THE KAMCHATKA PENINSULA BY EARLY TUESDAY
WHILE THE ECMWF HOLDS THE BLOCKING TILL LATE WEDNESDAY. THESE
DIFFERENCES WONT CAUSE CONCERN FOR THE PANHANDLE TILL NEXT
WEEKEND WITH THE DEVELOPMENT OF A GALE FORCE LOW IN THE GULF.
WILL NUDGE GRIDS TOWARD THE SLOWER ECMWF/NAEFS SOLUTION IN THE
LONGER TERM. TWEAKED THE GRIDS FOR THE SHORT TERM...SUNDAY NIGHT
AND MONDAY...FOR EARLY ONSET OF PRECIP AS MODELS HAVE SPED UP THE
ROTATION OF THE NEXT MID LEVEL WAVE AROUND THE LONG WAVE TROUGH
IN THE GULF.

THE PATTERN FOR THIS NEXT WEEK LOOKS VERY SIMILAR TO THE SOLUTION
OF THE MID SHIFT AS WEAK OFFSHORE FLOW WILL DEVELOP BY EARLY
WEDNESDAY. THE MAIN LONG WAVE TROUGH WILL REMAIN IN THE GULF
THROUGH LATE THURSDAY. THIS WILL KEEP A CHANCE OF PRECIP MAINLY
OVER THE SOUTHERN PANHANDLE WITH MOIST ALONG SHORE FLOW. THE
NORTHERN PANHANDLE WILL SEE A SLIGHT CHANCE OF PRECIP WEDNESDAY
THROUGH FRIDAY WITH THE DEVELOPMENT FOG IN JUNEAU AND GUSTAVUS
DURING THE EARLY MORNING PERIODS...AS THE OFFSHORE FLOW WILL BE
RELATIVELY WEAK.

WITH THE UPPER LONG WAVE TROUGH IN THE GULF SURFACE TEMPERATURES
ACROSS THE PANHANDLE WILL REMAIN BELOW NORMAL THROUGH THE WEEK
WITH 500 MB TEMPS IN THE -38 F TO -40 F RANGE AND 850 MB TEMPS
BETWEEN -7 F AND -10 F. THIS WILL ALLOW FOR CONTINUED SHOWER
ACTIVITY AND IN THE MODERATE TO HEAVY SHOWERS...SNOW WILL MIX TO
THE GROUND ACROSS THE PANHANDLE.

AS FAR AS WINDS EXPECT MIN GALE FORCE WINDS ALONG THE EASTERN
GULF MONDAY WITH BREEZY CONDITIONS ACROSS THE PANHANDLE. THEN
THROUGH NEXT FRIDAY WINDS WILL REMAIN RELATIVELY WEAK FOR THE
FIRST FULL WEEK OF SPRING. THERE IS MODERATE TO HIGH CONFIDENCE
IN THE LONG TERM THROUGH FRIDAY.

.AJK...WATCHES/WARNINGS/ADVISORIES
PUBLIC...HIGH WIND WARNING AKZ023 AND 027-028 3 PM TIL MIDNIGHT
         WIND ADVISORY AKZ027-028 TIL 3 PM
         WIND ADVISORY AKZ020-022, 024-026, AND 029 TONIGHT

MARINE...STORM PKZ036 TONIGHT
         GALE PKZ036 TODAY
         GALE PKZ021-035 041-052 TONIGHT

MM/PSS

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JUNEAU AK
257 AM ADT SUN MAR 23 2008

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0336 PM     NON-TSTM WND GST HYDABURG                55.21N 132.82W
03/22/2008  M61 MPH                             AK   AWOS

            HYDABURG AWOS REPORTED A WIND GUST OF 61 MPH.

&&

RWT