Small Craft Advisory 84, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
1130 AM AST THU FEB 8 2007

.SYNOPSIS...
.SHORT RANGE...
A STRONG UPPER LEVEL HIGH PRESSURE IS POSITIONED OVER THE
AREA...WITH LOW PRESSURE TO THE SOUTH OF THE AREA. THE BLOCKING
HIGH PRESSURE IS KEEPING THE LOWS TO THE SOUTH OF THE AREA...WITH
ONLY WEAK SHORTWAVES ROTATING UP INTO THE PANHANDLE AND
DISSIPATING AS THEY DO SO. SOME LIGHT RAIN AND SNOW HAS BEEN THE
RESULT FOR THE SOUTHERN PANHANDLE TODAY AND LAST NIGHT...WITH
THIS BAND STALLING OUT JUST SOUTH OF A SITKA TO WRANGELL LINE.
FOR TONIGHT AND EARLY TOMORROW...A VERY WEAK SHORTWAVE WILL
ROTATE AROUND THE NORTH SIDE OF THE UPPER LEVEL HIGH OVER THE
GULF. THIS SHORTWAVE HAS BROUGHT SOME LIGHT SNOW TO CORDOVA...AND
WILL HELP TO BRING A CHANCE OF LIGHT SNOW TO THE NORTHERN AND
CENTRAL PANHANDLE TONIGHT AND EARLY FRIDAY AS THIS SHORTWAVE
OVERRIDES THE COLD AIR IN PLACE AT LOW LEVELS. THE KEY WORD HERE
IS LIGHT. LOCAL WINDS WILL CONTINUE TO BE THE MAIN CONCERN WITH
THE STRONG OFFSHORE GRADIENT. HOWEVER...THE GRADIENT WILL
GRADUALLY DECREASE TONIGHT AND FRIDAY.

.LONG RANGE...NOT MUCH CHANGE IN THE WX OVER THE EXTENDED PERIOD.
A GENERALLY STABLE PATTERN OF HIGH PRESSURE TO THE NORTH...LOWER
PRESSURE SOUTH...AND DEFORMATION OVER THE PANHANDLE TENDS TO
RESULT IN CLOUDY BUT MORE OR LESS DRY WEATHER FOR SE AK.

WATER VAPOR SATELLITE IMAGERY SHOWS AT LEAST FOUR UPR VORT
CENTERS INTENSIFYING AND ROTATING CYCLONICLY AROUND A POINT NR 45
N 145W. GLOBAL MODELS AND ENSEMBLE MEAN ALL INDICATE SHORT WAVE
DYNAMICS AND MOISTURE WILL SWEEP N ALONG BC COAST THEN TURN
OFFSHORE OVER SOUTHERN PANHANDLE. THE REDIRECTION IS DUE TO THE
STUBBORN HIGH PRESSURE SFC/ALOF OVER SC AK AND YUKON.
PROBABLISTIC GUIDANCE FROM MESO MODELS SHOWS 30-60 PRECENT CHC OF
PRECIP OVER THE WEEKEND...HIGHER PROBABILITIES OVER SOUTHERN
ZONES... BUT VERY LITTLE IN THE WAY OF QUANTITY...SEVERAL
HUNDRETHS. TRANSLATION IS A DECENT CHANCE OF VERY LIGHT PRECIP.
EVEN SEAS STATE IS TRENDING FLATTER DAYS 2-5. THERE IS ONE ISSUE
TO WATCH FOR SUN-MON TIME FRAME WHICH IS THE POORLY INITIALIZED
SYSTEM CENTERED WEST OF N CALIF TODAY. THIS LOOKS STRONGER THAN
GFS SHOWS AND CERTAINLY HAS HI MOISTURE CONTENT BASED ON RAINFALL
IN NW CAL LAST NIGHT (1-3 INCHES). WILL WATCH IF THIS SYSTEM HAS
MORE PUNCH THAN CURRENTLY FCST WHEN IT APPROACHES SUN.

NO SIGFNT CHANGES TO PATTERN AND RESULTING WEATHER THROUGH ABOUT
WED. MODELS HINT THE HIGH PRESSURE TO OUR NORTH WILL FINALLY
WEAKEN LATE NEXT WEEK ALLOWING A WETTER SW FLOW TO RESTABLISH
OVER PANHANDLE.  TA

.AJK...WATCHES/WARNINGS/ADVISORIES
PUBLIC...WIND ADVISORY ZONES AND 18 19 AND 25.
MARINE...GALE WARNINGS ZONES 11 12 13 31.
         SMALL CRAFT ADVISORIES ZONES 21 22 32 33 34 35 41 42 43.