Gale Warning 108, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
1200 PM AST THU MAR 6 2008

.SYNOPSIS...
.SHORT RANGE...WEAKENING OCCLUSION ACROSS THE INNER CHANNELS OF
SOUTHEAST ALASKA WILL CONTINUE EAST AND SHOULD BE THROUGH ALL
AREAS BY EARLY AFTERNOON. THE UPPER RIDGE REBUILDS ACROSS
SOUTHEAST ALASKA FROM THE SOUTH THIS AFTERNOON AND EVENING.
BIORKA ISLAND RADAR SHOWS A SMALL BAND OF SHOWERS BEHIND THE
FRONT WITH ALMOST NO PRECIPITATION BEHIND THIS BAND. EXPECT RAIN
CURRENTLY OVER THE INNER CHANNELS THIS MORNING TO TRANSITION TO
SCATTERED SHOWERS THIS AFTERNOON AND THEN END FOR A SHORT
WHILE...PARTICULARLY ACROSS SOUTHERN ZONES...THIS EVENING.
HIGHEST POPS AND MOST QPF EXPECTED FOR PAYA WHERE CONTINUED
ONSHORE FLOW THROUGH THE EVENING COMBINED WITH APPROACHING SYSTEM
WILL KEEP PRECIPITATION CATEGORICAL THROUGH TONIGHT. DO NOT
ANTICIPATE MUCH OF A TEMPERATURE SPREAD TODAY WITH LOW LEVELS
NEARLY SATURATED AND MARINE LAYER CONTINUING TO MOVE ONSHORE.

NEXT LOW NEAR 50N/150W ALREADY AT 975 MB WITH FURTHER DEEPENING
STILL LIKELY THROUGH THE EVENING AS IT MOVES NORTH INTO THE
SOUTHERN GULF. THE LOW IS THEN FORECAST TO CURVE NW AND START TO
FILL LATE TONIGHT AND PASS JUST NORTH OF KODIAK ISLAND EARLY
FRIDAY. THE ASSOCIATED FRONTAL SYSTEM HAS A WELL DEVELOPED WARM
SECTOR THAT IS STARTING TO WRAP NORTHWARD THROUGH THE CENTRAL
GULF AS THE OCCLUSION PROCESS BEGINS. THE OCCLUSION IS FORECAST
TO MOVE THROUGH THE COASTAL WATERS FRIDAY MORNING AND THEN SLOWLY
WEAKEN AS IT MOVES THROUGH THE INNER CHANNELS FRIDAY AFTERNOON. A
MODEST SHOT OF CAA DIRECTLY BEHIND THE FRONT WILL MOVE TO THE
COAST IN THE LATE AFTERNOON.

GALE FORCE EAST TO SOUTHEAST WINDS AHEAD OF THE FRONT ARE
EXPECTED TO MOVES INTO THE SOUTHERN GULF LATE THIS AFTERNOON AND
SPREAD ACROSS ALL OF THE EASTERN GULF BY MIDNIGHT. SOME
INDICATION THAT A LOW LEVEL BARRIER JET WILL DEVELOP ACROSS THE
CAPE FAIRWEATHER TO CAPE SUCKLING ARCH AS STRONG MID LEVELS FLOW
IMPINGES UPON THE COASTAL TERRAIN IN THE 12Z TO 18Z PERIOD. THIS
COMBINED WITH A FAVORABLE SE PRESSURE GRADIENT ORIENTATION SHOULD
SUPPORT A MIN GALE THROUGH SOUTHERN AND CENTRAL INNER CHANNELS AS
WELL AS A WIND ADVISORY ALONG THE COAST BY LATE TONIGHT AND
THROUGH THE CENTRAL AND SOUTHERN ZONES FRIDAY MORNING. PRESSURE
GRADIENTS ACROSS SOUTHERN AND...TO A LESSOR EXTENT CENTRAL...
RELAX AS THE SURFACE TROUGH MOVES WHILE NORTHERN LYNN CANAL
GRADIENTS INCREASE WITH RISING PRESSURE TO THE SOUTH.

WITH A MODEST FETCH OF WARM MOIST AIR AND FAIRLY STRONG UVV
EXPECT MODERATE TO LOCALLY HEAVY RAIN ACROSS MOST OF THE AREA.
HEAVIEST PRECIPITATION IS FORECAST FOR PAYA AND THE NORTHERN
COAST WHERE 1.5 TO 3 INCHES OF RAIN IN 18 HOURS IS EXPECTED.
RAINFALL AMOUNTS WILL TAPER OFF FARTHER INLAND BUT MOST AREAS
STILL SHOULD SEE OVER 1 INCH THROUGH FRIDAY. THE AIRMASS REMAINS
MILD AND DO NOT EXPECT ANY ACCUMULATING SNOW BELOW 300 FEET AS
SNOW LEVELS CLIMB FROM AROUND 1000 FEET JUST AHEAD OF THE WARM
FRONT TO AROUND 2800 FEET MIDDAY. WILL MENTION UP TO 2 INCHES FOR
THE HIGHER ELEVATIONS OF THE HAINES AND KLONDIKE HIGHWAYS FRIDAY
MORNING. ALSO RAIN ALONG THE IMMEDIATE COAST COULD MIX WITH OR
EVEN CHANGE OVER TO SNOW OR ICE PELLETS DIRECTLY BEHIND THE FRONT
IN THE LATE AFTERNOON BUT SURFACE TEMPERATURES WILL BE TOO WARM
TO ACCUMULATE.

.LONG RANGE...SOUTHEAST ALASKA WILL REMAIN IN A VERY ACTIVE
WEATHER PATTERN THROUGH THE WEEKEND. THERE STILL SOME TIMING
ISSUES WITH THE NEXT COUPLE OF WEATHER FRONTS MOVING INTO THE
EASTERN GULF SO FORECASTER CONFIDENCE IS FAIR.

A FRONT MENTIONED ABOUT IN THE SHORT RANGE WILL BE LIFTING OVER
THE PANHANDLE THROUGH FRIDAY NIGHT AND THE RAIN WILL TRANSITION
TO SHOWERS AS THE ASSOCIATED UPPER TROF MOVES OVER THE AREA.
THERE IS SOME COLDER AIR BEHIND THIS FRONT THAT MAY HAVE SOME
SNOW MIXED IN WITH SOME OF THE STRONGER SHOWERS AS SNOW LEVEL
WILL LOWER TO NEAR SEA LEVEL THROUGH FRI NIGHT. THERE MAY BE A 1
TO 3 INCHES OF ACCUMULATIONS OVER THE FAR NORTHERN INNER CHANNELS
BUT AND 1 TO 2 INCHES OVER THE NEAR PAJN,PAGS,PAOH. A SURFACE
RIDGE WILL BUILD OVER SE AK OVER FRIDAY NIGHT SO SOME GUSTY
BREEZY WINDS WILL DEVELOP MAINLY OVER THE NORTHERN HALF OF THE
PANHANDLE. SHOWERS WILL BE LIKELY OVER MOST OF THE AREA THROUGH
SAT WITH THE A CHANCE OVER THE SOUTHERN THIRD AS THE RIDGE MAYBE
STRONG ENOUGH TO KEEP THE SHOWERS SUPPRESSED.

THE PARENT UPPER LOW OVER THE SOUTHERN BERING WILL ROTATE A
DEVELOPING STRONG UPPER LOW LIFTING OUT OF THE STRONG WESTERLY
FLOW OVER THE NORTH PACIFIC THROUGH SAT. THERE IS SOME TIMING
ISSUES WITH THIS SYSTEM SO THE TIMING WITH THIS MAY VARY BEFORE
IT GETS HERE BUT THE LATEST MODELS RUNS AREA COMING CLOSER ON A
SIMILAR SOLUTION. SO WITH THAT SAID...THE SURFACE LOW WILL DEEPEN
TO BE NEAR 970MB SAT NIGHT AS IT ENTERS THE SOUTH CENTRAL GULF
WITH AN OCCLUDED FRONT OVER THE PANHANDLE. THIS FRONT WILL
INCREASE WINDS TO GALES OVER THE COASTAL WATERS WITH POSSIBLE
STORMS IN THE NORTHERN GULF WITH A BARRIER JET DEVELOPMENT. SE AK
WILL SEE WINDY CONDITIONS OVER MOST AREAS WITH THE STRONG WINDS
BE OVER THE COASTAL AREAS AND SOUTHERN INNER CHANNELS...THESE
AREAS COULD NEED A WIND ADVY FOR THIS EVENT. THE WINDS WILL BEGIN
TO DIMINISH LATE SAT AFTERNOON AND CONTINUE INTO THE EVENING TIME
FRAME.

THE LOW WILL DRIFT NORTHWEST TO BE OVER THE NW GULF BY SAT
AFTERNOON AND THEN OVER PANC BY EARLY SUN MORNING. THE UPPER TROF
WILL LIFT OVER THE PANHANDLE BY SAT AFTERNOON AND SHOWERS WILL BE
DOMINATE. THERE WILL REMAIN TO BE STRONG ONSHORE FLOW THROUGH THE
MID-LEVELS SO THE SHOWERS WILL BE FAIRLY MODERATE ESPECIALLY NEAR
STEEP TERRAIN. A UPPER RIDGE WILL BEGIN TO BUILD OVER THE
SOUTHERN AREAS LATE SUN THAT MAY WEAKEN THE SHOWERS MOVING
ONSHORE.

FOR THE EARLY NEXT WEEK...THE PARENT LOW OVER THE BERING WILL
BEGIN TO DRIFT EAST OVER THE GULF AND LIFT INTO THE YUKON BY TUE
NIGHT AS THE UPPER RIDGE MENTIONED ABOVE ELONGATES ACROSS THE
GULF THROUGH TUE. THE HIGH WILL PINCH OFF NEAR THE AK PENINSULA
AND LINK UP WITH A RIDGE BUILDING OVER THE NORTH PACIFIC WED. A
UPPER TROF OVER THE NORTHEAST PACIFIC WILL MOVE INTO THE EASTERN
GULF WED NIGHT. SO WITH THAT SAID...EARLY NEXT WEEK WILL SEE
SHOWERS MOVING ONSHORE WITH RELATIVE WEAK WINDS OVER MOST OF THE
PANHANDLE.

.AJK...WATCHES/WARNINGS/ADVISORIES
PUBLIC...WIND ADVISORY AKZ017,022,023,027 3 AM TO NOON FRIDAY
                       AKZ020,024-026,028 6 AM TO 3 PM FRIDAY

MARINE...GALE PKZ041-052 310 TONIGHT AND FRIDAY
              PKZ022,035-036 AND POSSIBLY 031 FRIDAY MORNING
         SMCR ELSEWHERE