Small Craft Advisory 124, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
258 PM AKST THU FEB 4 2016

.SHORT TERM...ACTIVE WEATHER ACROSS SOUTHEAST ALASKA TODAY AND
INTO TONIGHT BEFORE AN ABRUPT SHIFT TO QUIETER WEATHER ON FRIDAY.
FRONT CROSSING THE PANHANDLE TODAY HAS RESULTED IN GUSTY WINDS,
MODERATE RAINFALL, AND HEAVY SNOW. REPORTS HAVE INDICATED SEVERAL
INCHES OF SNOW HAS FALLEN ON THE HAINES HIGHWAY WITH ACCUMULATING
SNOWFALL ALSO OCCURRING IN SKAGWAY AND ALONG THE KLONDIKE HIGHWAY.
SIGNIFICANT SNOW IS ALSO UNDERWAY IN THE HYDER AREA WITH THE
STEWART,BC OBSERVATION CURRENTLY REPORTING MODERATE SNOW AND 1/2
MILE VISIBILITY. WINDS HAVE BEEN GUSTY ACROSS A LARGE PORTION OF
THE PANHANDLE BUT STRONGEST OVER THE SOUTHERN PANHANDLE WHERE
GUSTS OF 50-60 MPH HAVE BEEN OBSERVED. THIS FRONT WILL WEAKEN
OVER THE PANHANDLE AND SLOWLY SHIFT TO THE SOUTH AND EAST THROUGH
LATE TONIGHT. A WAVE WILL DEVELOP ALONG THE FRONT AND MOVE ACROSS
THE SOUTHERN PANHANDLE LATE THIS EVENING. A BREAK IN THE ACTIVE
WEATHER WILL TAKE PLACE ON FRIDAY AS A WEAK RIDGE OF HIGH PRESSURE
BUILDS OVER SOUTHEAST ALASKA.

A DRY SLOT SHIFTING INTO THE NORTHERN HALF OF THE PANHANDLE IS
EVIDENT ON SATELLITE IMAGERY EARLY THIS AFTERNOON. AM EXPECTING
PRECIPITATION RATES TO QUICKLY DIMINISH THIS AFTERNOON SO WILL BE
CANCELLING THE WINTER WEATHER PRODUCTS FOR THE HAINES AND SKAGWAY
ZONES AT 4 PM. STRONG SOUTHERLY FLOW IS BRINGING AN IMPRESSIVE
PLUME OF MOISTURE INTO THE SOUTHERN PANHANDLE AND ONLY EXPECT THIS
REGION OF ENHANCED LIFT TO INCREASE THIS EVENING AS THE DEVELOPING
WAVE MOVES CLOSER. FEELING IS PRECIPITATION RATES WILL BE HIGH ENOUGH
TO KEEP AN ISOTHERMAL PROFILE AT FREEZING IN HYDER EVEN WITH WARM
AIR ADVECTING IN ALOFT. DUE TO THIS UPGRADED THE WINTER WEATHER
ADVISORY TO A WINTER STORM WARNING UNTIL 5 AM FRIDAY MORNING WITH
10-14 INCHES OF ACCUMULATION ANTICIPATED.

GUSTY WINDS ARE THE OTHER MAIN STORY TODAY ESPECIALLY OVER THE
SOUTHERN PANHANDLE. AS THE WAVE MOVES OVER THE SOUTHERN AREAS THIS
EVENING EXPECT GUSTS TO BE ENHANCED WITH FREQUENT GUSTS TO 60 MPH
OVER PRINCE OF WALES AND IN THE VICINITY OF KETCHIKAN. THESE WINDS
WILL QUICKLY DIMINISH OVERNIGHT AS THE LOW LEVEL JET WEAKENS AND
SHIFTS EAST BEHIND THE DEPARTING WAVE.

THE FORECASTED WEATHER ON FRIDAY CAN BE SUMMED UP WITH SCATTERED
SHOWERS AND SIGNIFICANTLY LIGHTER WINDS AS A WEAK RIDGE OF HIGH
PRESSURE BUILDS OVER THE PANHANDLE. AN UPPER LEVEL TROUGH WILL
LIFT INTO THE NORTHEAST GULF ON FRIDAY AFTERNOON INCREASING SHOWER
ACTIVITY ESPECIALLY ALONG THE NORTHEAST GULF COAST.

USED THE 12Z NAM AND HIRES GUIDANCE FOR UPDATES TO THE SHORT RANGE
FORECAST.

.LONG TERM...MODEL GUIDANCE SHOWS UPPER TROUGHING PERSISTING OVER
THE ALEUTIANS/NCNTRL PAC REGION THROUGHOUT THE LONG TERM
PERIOD...WHICH WILL FORCE QUASI-PERMANENT RIDGING OVER THE W
COAST OF N AMERICA. THIS WILL FOCUS WARM...MOIST...DEEP-LAYER SLY
FLOW EMANATING FROM THE SUBTROPICS OVER THE SRN HALF OF THE
PANHANDLE BY SUN...WHICH IS FORECAST TO CONTINUE IN EPISODIC
FASHION THROUGH NEXT THU. PERIODS OF MODERATE TO HEAVY RAIN WILL
BE POSSIBLE AS A RESULT ON SUN AS A SHORTWAVE TROUGH MOVES N
ACROSS THE ERN GULF. PLUME OF RICH MOISTURE CONTINUES OVER THE SRN
PANHANDLE MON-MON NIGHT...WITH THE PATTERN TRANSITIONING TO A MORE
PROGRESSIVE REGIME AS A SERIES OF SHORTWAVES MOVE FROM THE NERN
PAC NNW ACROSS THE GULF/PANHANDLE.

IN ADDITION TO HEAVY RAIN...HEAVY SNOW WILL BE POSSIBLE FOR HYDER
DURING THE SUN-MON TIME FRAME AS HIGH PRESSURE OVER BC LOCKS IN
SURFACE TEMPERATURES NEAR FREEZING. AIRMASS IS FORECAST TO
MODERATE STRONGLY AFTER MON AS VERY WARM AIR SPREADS N WITH
INCREASING SLY LOW-LEVEL FLOW. INHERITED TEMPERATURE GRIDS SHOWED
THE MODERATING TREND FAIRLY WELL. PRESSURE GRIDS WERE UPDATED WITH
AN ECMWF/GFS BLEND THROUGH SAT...THEN TRANSITIONED TO LATEST WPC
BY SUN. REMAINDER OF THE FORECAST WAS ALSO UPDATED WITH AN
ENSEMBLE BLEND.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...HIGH WIND WARNING UNTIL 9 PM AKST THIS EVENING FOR AKZ027.
     STRONG WIND UNTIL 3 PM AKST THIS AFTERNOON FOR AKZ023-025.
     HIGH WIND WARNING UNTIL MIDNIGHT AKST TONIGHT FOR AKZ028.
     WINTER STORM WARNING UNTIL 5 AM AKST FRIDAY FOR AKZ029.
MARINE...STORM WARNING FOR PKZ036.
     GALE WARNING FOR PKZ022-035-041>043-051-052.
     SMALL CRAFT ADVISORY FOR PKZ013-021-031>034.
     SMALL CRAFT ADVISORY DUE TO SEAS FOR PKZ053.
&&

TPS/GARNER

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

PRELIMINARY LOCAL STORM REPORT...CORRECTED
NATIONAL WEATHER SERVICE JUNEAU AK
1129 AM AKST THU FEB 04 2016

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0740 AM     HEAVY SNOW       40 NW HAINES            59.65N 136.25W
02/04/2016  M10.5 INCH       XXX                XX   CO-OP OBSERVER

            HAINES CUSTOMS

0800 AM     SNOW             HAINES                  59.24N 135.44W
02/04/2016  M2.3 INCH                           AK   CO-OP OBSERVER

            HAINES COOP

0930 AM     SNOW             6 SSE HAINES            59.16N 135.38W
02/04/2016  M3.0 INCH                           AK   TRAINED SPOTTER

            NEW SNOWFALL, VERY WET AND SLUSHY

&&

GLS