• Juneau, Alaska, United States (99801)
  • WxZone: AKZ025ICAO: PAJNLat: 58.30NLon: 134.42W

Discussions

356 PM AKST SAT MAR 13 2010

.SHORT TERM...THE LATEST SATELLITE IMAGERY SHOWS AS STORM FORCE
FRONT LIFTING INTO THE EASTERN GULF WITH THE PARENT LOW OVER THE
SOUTHERN GULF. THIS FRONT WILL LIFT OVER THE PANHANDLE THROUGH
TONIGHT AND SLOWLY PUSH EAST INTO CANADA BY LATE SUN AFTERNOON.
THERE ARE SOME LINGERING SNOW SHOWERS OVER THE NORTHERN THIRD OF
SE AK WITH MINOR SNOW ACCUMULATION. THE FRONT IS MOVING OVER THE
SOUTHERN AREAS ATTM WITH RAIN AND VERY WINDY CONDITIONS. THE
FRONT WILL CONTINUE TO LIFT NORTH THROUGH THE DAY AND SPREAD
STEADY PRECIP OVER THE NORTH CENTRAL AREAS BY THE AFTERNOON. 

 THE FRONT WILL CONTINUE TO PRODUCE VERY STRONG WINDS GUST TO
60 MPH OR MORE THROUGH TONIGHT OVER THE FAR SOUTHERN ZONES. THE
REST OF THE COASTAL AREAS AND THE CENTRAL PANHANDLE WILL SEE WIND
ADVY LEVEL GUSTS DEVELOP THROUGH THE DAY AND PERSIST THROUGH
TONIGHT. THE REST OF THE PANHANDLE WILL SEE BREEZY TO WINDY
CONDITIONS WITH THE EXCEPTION TO THE FAR NORTHERN AREAS AS THE
PRESSURE GRADIENT IS NOT FAVORABLE FOR STRONG WINDS. AS THE
PRECIP LIFTS NORTH WITH THE FRONT THE NORTHERN CENTRAL AREAS WILL
SEE THE SNOW CHANGE OVER TO RAIN AS THERE IS A WARM AIR
ASSOCIATED WITH THE FRONT. THE FAR NORTHERN AREAS WILL STAY ALL
SNOW THROUGH TONIGHT BUT CHANGE OVER TO RAIN THROUGH SUN MORNING.
SO WITH THAT SAID WILL CONTINUE THE WINTER STORM WARNING FOR ZONE
19 BUT THERE IS LOW CONFIDENCE AS WITH A E/W PRESSURE GRADIENT
THERE WILL NOT BE MUCH CAA INTO THE AREA AND THE WARMER AIR ALOFT
MAY MIX DOWN TO THE SURFACE TO CHANGE THE SNOW TO RAIN. SNOW
AMOUNTS WILL RANGE FROM 6 TO 8 INCHES THROUGH TONIGHT.  

 WINDS OVER THE WATER WAYS WILL REMAIN TO BE VERY STRONG WITH
STORM FORCE WINDS OVER THE SE GULF THIS AFTERNOON THAT MAY LAST
INTO THE EARLY EVENING HOURS. THE STORMS FOR THE CLARENCE STRAIT
WILL CONTINUE THROUGH THE EVENING BEFORE DIMINISHING TO GALES BY
LATE TONIGHT. GALE FORCE WINDS WILL CONTINUE OVER THE REST OF THE
GULF ALONG WITH THE E/W MARINE WATERS OF THE INNER CHANNELS. N/S
WATER WAYS WILL SEE SMALL CRAFT WINDS FROM THE S WITH HIGHER
GUSTS THROUGH TONIGHT. OVER NORTHERN LYNN CANAL THE WINDS WILL
REMAIN TO BE LESS THAN 20KT WITH VARIABLE WIND DIRECTION. 

 AS THE FRONT LIFTS TO THE EAST THROUGH SUN THE WINDS WILL
DIMINISH TO LESS THAN 25 KT BY THE AFTERNOON. THE EASTERN GULF
WILL CONTINUE TO SEE SMALL CRAFT WINDS ALONG WITH VERY LARGE SEAS
FROM THE S SWELL. RAIN SHOWERS WILL PERSIST OVER THE PANHANDLE
THROUGH SUN WITH SNOW NEAR PAHN SWITCHING TO RAIN. THE PARENT
SURFACE LOW WILL REMAIN IN THE GULF THROUGH SUN AND WEAKEN AS
WILL BECOME VERTICALLY STACKED THROUGH SUN.  

.LONG TERM...WEAKENING COMPLEX OF SURFACE LOW PRESSURE SYSTEMS
CONTINUE TO DUMBBELL AROUND EACH OTHER IN THE NORTHERN GULF AS
FRONTAL SYSTEM FROM THE PARENT LOW SLOWLY DISSIPATES OVER THE
PANHANDLE EARLY IN THE LONG TERM. WINDS WILL CONTINUE TO WEAKEN AS
SHOWER ACTIVITY ROTATES OUT OF THE GULF AND INTO THE PANHANDLE.
MODERATE COLD POCKET ALOFT WILL ALLOW FOR MIXED PRECIPITATION IN
THE PAYA PAHN AND PAGY AREAS WHILE AREAS SOUTH OF THESE ZONES WILL
BE PRIMARILY RAIN SHOWERS. EXPECTING ONLY MINOR SNOW ACCUMULATION
UP TO AN INCH TO TWO IN THESE AREAS.

 MONDAY WILL PROVIDE A SHORT BREAK TO THE VERY ACTIVE WEATHER
PATTERN. PARENT LOW CONTINUES TO WEAKEN IN THE GULF AND SLOWLY MOVE
TO THE WEST AS 985 MB LOW DEVELOPS SOUTHWEST OF THE QUEEN
CHARLOTTE ISLAND TUESDAY AND MOVES INLAND NEAR PAKT AS AN 1005 MB
LOW WEDNESDAY MORNING. WINDS WILL INCREASE IN THE SOUTHERN PORTION
OF THE PANHANDLE AS THE LOW APPROACHES WITH ADVISORY LEVEL GUSTS
POSSIBLE TUESDAY NIGHT AND WEDNESDAY MORNING. AS THE LOW
APPROACHES A FRONT WILL WRAP INTO THE SOUTHERN ZONES AND MOVE
NORTH AND NORTHWESTWARD ACROSS THE PANHANDLE WEDNESDAY. DRY
OFFSHORE FLOW IN THE LOW LEVELS WILL OFFSET SYNOPTIC SCALE LIFTING
TO THE NORTH OF THE LOW AND LIMIT PRECIP AMOUNTS.

 AS THIS LOW PASSES INTO THE INTERIOR OF BC FLOW AROUND THE BACK
SIDE OF THE LOW SHOULD HELP USHER IN A COLD AIR MASS POSITIONED BY
THIS TIME OVER EASTERN INTERIOR OF ALASKA AND THE YUKON. A 1046
MB HIGH PRESSURE SYSTEM OVER THE YUKON WILL GENERATE A COLD
AIR MASS FOR THIS TIME OF YEAR AS 1000 TO 500 MB THICKNESS VALUES
DIP TO 498 TO 502 DM. COLD DENSE AIR MASS BACK UP AGAINST THE
COASTAL MOUNTAINS WHERE GAP FLOWS INTO THE PANHANDLE BEGIN
THURSDAY IN THE NORTHERN AREAS AND FRIDAY IN THE SOUTHERN AREAS.
THE AIR MASS WILL BE ON THE MOVE AND WITH HIGHER SUN ANGLE OF MARCH
WILL NEED TO SEE LATER MODEL RUNS TO DETERMINE IF AIR MASS WILL BE
DENSE ENOUGH AND DEEP ENOUGH FOR GAP WIND EVENT BY LATE WEEK.

 GFS IS THE BULLISH MODEL FOR A COLD AIR MASS TO DEVELOP AND MOVE
SOUTHEAST OUT OF THE YUKON AND INTO NORTHERN AND CENTRAL BC. EC IS NOT
NEARLY AS AGGRESSIVE WITH THIS SOLUTION AND DEVELOPS A SOLUTION
THAT MAINTAINS SOUTHERLY TO SOUTHEASTERLY FLOW ACROSS THE PANHANDLE.
THE OPERATIONAL GFS HAS COME INTO LINE WITH THE EC AND UKMET
THROUGH THE MIDDLE OF NEXT WEEK. MODEL SPREAD WAS MINIMAL AMONG
GFS ECMWF AND NAM FOR THE TOMORROW NIGHT PERIOD THROUGH DAY 4. A
BLEND OF THE GFS AND NAM WAS USED TO UPDATE GRIDS AT HAND OFF
WITH THE SHORT TERM WHILE THE LATEST HPC GUIDANCE WAS USED TO
UPDATE FROM DAY 4 THROUGH THE END OF THE PERIOD. FORECAST CONFIDENCE
IS ABOVE AVERAGE THROUGH DAY 4 AND THEN DECREASES TO BELOW AVERAGE
WITH THE THE PRONOUNCED MODEL SPREAD BEYOND THAT POINT.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...WIND ADVISORY UNTIL 4 AM AKDT SUNDAY FOR AKZ026.
         HIGH WIND WARNING UNTIL 4 AM AKDT SUNDAY FOR AKZ027-028.
         WIND ADVISORY UNTIL 4 AM AKDT SUNDAY FOR AKZ022-023.
         WINTER STORM WARNING UNTIL 10 AM AKDT SUNDAY FOR AKZ019.
         WIND ADVISORY UNTIL 4 AM AKDT SUNDAY FOR AKZ029.
MARINE...STORM WARNING FOR PKZ036-041>043. 
         GALE WARNING FOR PKZ013-021-022-033>035-051-052. 
         SMALL CRAFT ADVISORY FOR PKZ031-032. 

&&

$$

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