Area Forecast Discussion
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FXAK67 PAJK 271347
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
447 AM AKST TUE JAN 27 2015

.SHORT TERM...CLOUDS OF GENERALLY MID LEVEL OVER THE SOUTHERN
PANHANDLE ASSOCIATED WITH LOW IN WESTERN BRITISH COLUMBIA JUST
SOUTHEAST OF MISTY FJORDS. LITTLE IN WAY OF PRECIPITATION BEING
REPORTED AT STATIONS IN ALASKA FROM THE LOW...THOUGH PRINCE RUPERT
HAS CONTINUED ONGOING RAIN THERE. THE LOW AND THE ASSOCIATED
CLOUDS WILL PULL EAST THROUGH EARLY TUESDAY MORNING. A POCKET OF
PARTLY CLOUDY SKIES ACROSS THE NORTH CENTRAL TO NORTHERN
PANHANDLE...WITH A BAND OF CIRRUS FLOWING ACROSS THE REGION. THE
HIGH PRESSURE OVER THE EASTERN GULF IS BEGINNING TO BE SQUEEZED AS
THE NEXT WEATHER SYSTEM IS LIFTING NORTHEAST INTO THE SOUTHWEST
GULF. THE SURFACE LOW IS MOVING NORTHWARD ALONG 155 WEST AND WILL
START TO PULL WEST SLIGHTLY TONIGHT.

THE FRONT HAS AN EASTWARD MOVEMENT TO IT AS WELL SO EXPECT THE
FRONTAL BAND TO TRY AND START SHEARING APART SOME. THE
PRECIPITATION WILL APPROACH THE PANHANDLE COAST FROM CROSS SOUND
SOUTHWARD TUESDAY NIGHT WITH SOME EARLY PRE-FRONTAL PRECIPITATION
PUSHING AS FAR INLAND AS JUNEAU BY LATE TUESDAY NIGHT. THE RAIN
SNOW LINE WILL BE LIFTING NORTHWARD OVERNIGHT TO LIE FROM JUST
NORTH OF SITKA TO FREDERICK SOUND. THINK THAT NORTHERN PANHANDLE
WILL PICK UP TO ROUGHLY A HALF INCH OR LESS OF SNOW BY WEDNESDAY
MORNING.

WINDS IN BOUND IN THE MARINE WATERS TUESDAY NIGHT I THINK I WILL
INCREASE UP TO GALE FORCE. GUSTS ALONG COASTAL CAPES WILL INCREASE
OVERNIGHT.

EARLY THIS MORNING OVER THE FAR NORTHERN PANHANDLE STRONG WIND
HEADLINE IS GOING ON FOR SKAGWAY WITH GALE FORCE FOR NORTHERN LYNN
CANAL. THESE ARE EXPECTED TO DIMINISH THIS MORNING. FORECAST
CONFIDENCE IS ABOVE AVERAGE FOR TUESDAY.

.LONG TERM...A GALE FORCE FRONT WILL BE IN THE PROCESS OF MOVING
INLAND OVER SRN COASTAL AREAS AT THE START OF THE LONG TERM /WED
MORNING/. AS THIS OCCURS...STRONG WINDS WILL BE PROBABLE NEAR
HYDABURG. PRECIPITATION WILL ALSO BE SPREADING ACROSS THE
REGION...WITH LOCALLY HEAVY RAINFALL POSSIBLE OVER THE SRN
PANHANDLE WHERE PW VALUES FROM 0.5-0.8 INCH AND A 40+ KT SLY LLJ
WILL YIELD STRONG MOISTURE FLUX. MEANWHILE...SUBFREEZING BOUNDARY
LAYER TEMPERATURES OVER CNTRL/NRN AREAS WILL FAVOR LIGHT SNOWFALL.
LOCATIONS SUCH AS JUNEAU AND YAKUTAT WILL GRADUALLY WARM INTO THE
LOW/MID 30S BY THU...RESULTING IN RAIN MIXED WITH PERIODS OF SNOW.
MEANWHILE...HAINES...SKAGWAY AND HYDER WILL HOLD ON TO FREEZING
SURFACE TEMPERATURES DUE TO NLY WINDS...AND THIS WILL LEAD TO A
LONGER DURATION OF LIGHT SNOWFALL.

DETERMINISTIC MODEL GUIDANCE IS IN GOOD AGREEMENT SHOWING A LARGE
DEEP-LAYER CYCLONE FORMING SSE OF THE ALEUTIANS BY FRI
NIGHT...WITH NARROW RIDGING DEVELOPING OVER THE ERN-NRN GULF. THIS
PATTERN IS CURRENTLY EXPECTED TO YIELD A DRY AIRMASS OVER THE
PANHANDLE AND REDUCTION IN PRECIPITATION CHANCES. DRYING WILL BE
FURTHER AIDED BY A TIGHTENING OFFSHORE ORIENTED PRESSURE GRADIENT
AS HIGH PRESSURE STRENGTHENS OVER NWRN CANADA. SIGNIFICANT OUTFLOW
WINDS APPEAR PROBABLE DURING THE WEEKEND AS THIS TAKES
PLACE...WITH GALES DEVELOPING FOR BOTH LYNN CANAL AND CROSS
SOUND/WRN PORTIONS OF ICY STRAIT...AND STRONG NELYS OVER SKAGWAY.
MOUNTAIN WAVE DEVELOPMENT OVER DOWNTOWN JUNEAU/S DOUGLAS CANNOT
BE RULED OUT EITHER. A FRONT IS FORECAST TO APPROACH THE SRN
PANHANDLE SAT NIGHT INTO SUN...WITH MIDLEVEL MOISTURE SPREADING
NWD INTO THE CNTRL PANHANDLE. HOWEVER...PRECIPITATION IS EXPECTED
TO BE LIGHT AT BEST DUE TO THE DRY LOW-LEVEL OFFSHORE FLOW.

NO CHANGE WAS MADE TO INHERITED PRESSURE GRIDS. CHANGES TO POP/QPF
WERE MINIMAL...BUT A COMBINATION OF THE GFS AND ECMWF WAS USED
WHEN CHANGES APPEARED WARRANTED. PRIMARY MODIFICATION WAS A
REDUCTION IN POP/QPF DURING THE WEEKEND DUE TO THE DRY SIGNAL
PRESENT IN AVAILABLE DETERMINISTIC GUIDANCE. FORECAST CONFIDENCE
IS AROUND AVERAGE.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...STRONG WIND UNTIL 6 AM AKST EARLY THIS MORNING FOR AKZ018.
MARINE...GALE WARNING FOR PKZ041>043.
         SMALL CRAFT ADVISORY FOR PKZ011-012-021-022-032>036-051-052.

&&

$$

BEZENEK/GARNER

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