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800
FXAK67 PAJK 290103
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
403 PM AKST FRI NOV 28 2014

.SHORT TERM...VERY QUIET DAY BETWEEN STORM SYSTEMS HERE IN THE
PANHANDLE WITH THE POST-FRONTAL COLD AIR MASS FIRMLY IN PLACE AT LOW-LEVELS.
ONLY RESIDUAL WINDS AT FIVE FINGERS (25 KT), SKAGWAY AREA (15 KT)...ELDRED
ROCK IS DOWN TO G22 AT THE MOMENT. NO DOUBT THAT SOME SOUTHEASTERN
PASSES STILL HAVE OUTFLOW BUT THIS SHOULD BE DIMINISHING OVER THE
NEXT FEW HOURS. THE PRIMARY CHANGES FOR GRIDS TONIGHT ARE COOLING
MOST SEA LEVEL AREAS WHERE IT IS ANTICIPATED TO BE MOSTLY CALM
OVERNIGHT...SHAVED A FEW DEGREES OFF THE LOWS FOR MANY AREAS AS
DEW POINTS VERY LOW IN THE WAKE OF THE COLD OUTFLOW YESTERDAY.
WILL MAKE FOR A VERY COLD NIGHT OVER THE PANHANDLE. ALSO AS THE
NEW LOW BEGINS TO DEVELOP OVER THE NORTHERN GULF
SATURDAY...ANTICYCLONIC LOW-LEVEL WINDS OFFSHORE OVER ZONES 41, 42
AND EASTERN 310 WILL INCREASE SOMEWHAT BUT DON`T THINK THEY WILL
GET TO WIDELY SUSTAINED 25 KT BASED ON NEW MODEL LOW-LEVEL
PRESSURE GRADIENT FORECASTS. SO TWEAKED THE WINDS DOWN IN THIS
REGION FOR SATURDAY AFTERNOON. A DETAILED ANALYSIS OF LOW-LEVEL
CONDITIONS INDICATES THAT THE ONLY AREAS WHICH MAY HAVE MIXED
PRECIPITATION ON LATE SAT ARE ZONES 22 AND 23...IN THE COASTAL
SITKA AND ELFIN COVE AREAS WHERE 850 TEMPS ARE ABOVE -6C OR SO
LATE AFTERNOON. EVEN THERE ONLY INCLUDED A CHANCE OF RAIN MIXING
IN AS PRE- STORM DRY AIR/EVAP WILL CONTRIBUTE TO COOLING AND MAY
DELAY THIS. OTHERWISE LOW-LEVEL TEMPERATURES AREA-WIDE ARE PRIMED
FOR SNOW DEVELOPMENT LATE SATURDAY/EVENING AS COASTAL TROUGH
DEVELOPS, LOW APPROACHES AND OVERRUNNING OF COLD AIR MASS BEGINS.
ONLY LIGHT PRECIP EXPECTED IN THIS PERIOD THOUGH. WAVE ALOFT IS AT
ABOUT 148W ON NAM GUIDANCE AT 03Z SATURDAY AND HEADING EAST.
UTILIZED COMBO OF EC/NAM AND INHERITED QPF DATA FOR MOISTURE
FIELDS. MODEL CONFIDENCE IS AVERAGE.

.LONG TERM...LIONS SHARE OF THE FORECAST TIME WAS SPENT LOOKING AT
THE INCOMING WEATHER SYSTEM FOR LATE SATURDAY AND SUNDAY. ORIGINALLY
WAS GOING WITH SUBSET OF THE EVENTUAL WATCH THAT WAS ISSUED BUT
THE SURROUND AREAS WERE BORDERLINE ENOUGH THAT A `ADVISORY LEVEL`
AMOUNTS COULD HAPPEN SO INCLUDED THEM INTO THE FORECAST SITUATION.

THE COOLER AIR PRIMED THE INNER CHANNELS FOR AN OVERRUNNING SNOW
EVENT STARTING SATURDAY AFTERNOON TO SUNDAY AFTERNOON AND TO
SUNDAY NIGHT FOR THE MISTY FJORD SOME OF THE SNOW AMOUNTS
DEPENDING ON MODELS ARE BORDERLINE FOR SNOW ADVISORY BUT WENT HEAD
AND HIGHLIGHT IT ANYWAY. SNOWFALL IN THE JUNEAU AREA LIKELY TO BE
IN THE 4 TO 8 INCH RANGE BUT THINK THE BIGGEST HAZARD WILL BE THE
MOTORISTS TRYING TO REMEMBER HOW TO DRIVE ON THE WHITE STUFF
AGAIN. WEATHER SYSTEMS IS A TYPICAL WEAK LOW CUTTING ACROSS THE
NORTHERN GULF WITH UPPER LEVEL SUPPORT AND FAIR BIT OF MOISTURE.
BEST AREAS OF SNOW ALONG THE ICY STRAIT AREA TO JUNEAU AND THEN
SOUTHWARD TO WRANGELL PETERSBURG AND HYDER.

THERE IS POSSIBLE ADVISORY FOR THE YAKUTAT AREA AS WELL. WITH THE
WEAKER SYSTEM AND NOT EXPECTING BIG WINDS WITH LOW AND TROUGH
FEATURE. BEHIND THE FIRST LOW IT LOOKS LIKE THERE COULD BE A BIT
OF COOLING BEFORE THE NEXT WEAKENING FRONTAL BAND FROM THE BERING
SEA LOW TO SPREAD IN FOR TUESDAY. THERE COULD BE A FEW MORE INCHES
OF SNOW FROM THAT DEPENDING ON LOCATIONS. OTHERWISE IT IS
SOUTHWEST FLOW ALOFT SO LOOKING FOR A SLOW WARM-UP FOR MUCH OF
THE PANHANDLE END OF THE WEEK.


&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY
     AFTERNOON FOR AKZ020>022-024>026.
         WINTER STORM WATCH FROM SUNDAY MORNING THROUGH SUNDAY AFTERNOON
     FOR AKZ028.
         WINTER STORM WATCH FROM SUNDAY MORNING THROUGH SUNDAY EVENING
     FOR AKZ029.
MARINE...SMALL CRAFT ADVISORY DUE TO SEAS FOR PKZ041>043.

&&

$$

WESLEY/BEZENEK

VISIT US AT HTTP://WWW.WEATHER.GOV/JUNEAU








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