Small Craft Advisory 196, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
255 PM AKST SAT FEB 27 2016

.SHORT TERM...A LARGE LOW PRESSURE SYSTEM CAN BE SEEN ON SATELLITE
WITH AN OCCLUDED FRONT SPANNING THE ENTIRE GULF OF ALASKA. STORM
FORCE GUSTS HAVE BEEN OBSERVED ALONG THIS FRONT OVER THE CENTRAL
GULF AND GALE FORCE WINDS ELSEWHERE. EXPECT THESE WINDS TO
CONTINUE THIS EVENING AS THE FRONT MOVES CLOSER TO THE
COAST...THEN GRADUALLY EASE AS IT MOVES OVER LAND TONIGHT. SEAS
HAVE ALSO COME UP WITH OFFSHORE BUOY 46085 REPORTING COMBINED
SEAS UP TO 21FT.

RAIN ASSOC WITH THE FRONT IS STARTING TO MOVE INTO THE COAST LATE
THIS AFTERNOON AND WILL SPREAD INLAND OVERNIGHT. THE SOUTHERN
OUTER COAST WILL SEE RAIN BECOME HEAVY AT TIMES THIS EVENING ALONG
WITH WIND GUSTS OF 40-45MPH. INSIDE WATERS OPEN TO THE OCEAN SUCH
AS CROSS SOUND, CAPE DECISION AND CLARENCE STRAIT WILL ALSO SEE
THEIR WIND INCREASING TO GALE FORCE THIS EVENING. OTHER INSIDE
WATERS WILL INCREASE TO SMALL CRAFT LEVEL WITH THE HIGHEST SPEEDS
THROUGH E-W PASSES.

THE PARENT LOW WILL PROGRESS TO THE NW GULF BY SUNDAY MORNING AND
THE MAIN PART OF THE FRONT WILL HAVE PASSED. PRECIP WILL
TRANSITION TO SHOWERS BEHIND THE FRONT. EXPECT BANDS OF SHOWERS
WILL CONTINUE TO WRAP AROUND THE PARENT LOW AND MOVE OVER THE
PANHANDLE THROUGH THE DAY SUNDAY. AFTER ONE SUCH BAND...WINDS WILL
SHIFT TO THE S-SW IN THE AFTERNOON. THE PRESSURE GRADIENT WEAKENS
AT THIS TIME BUT WOULD NOT BE SURPRISED TO SEE SOME GUSTY WINDS
NEAR SHOWERS. CAPE VALUES OVER THE GULF RISE 100-200J/KG TONIGHT
THROUGH SUNDAY...SO HAVE CONTINUED WITH A SLIGHT CHANCE OF THUNDER
OVER THE OUTSIDE WATERS.

MODELS WERE IN GOOD AGREEMENT WITH THIS FRONT. USED AN ENSEMBLE
APPROACH FOR UPDATES. FORECASTER CONFIDENCE IS ABOVE AVERAGE.

.LONG TERM...QUASI-STATIONARY ZONE OF UPPER TROUGHING OVER THE
NCNTRL PAC/ALEUTIANS REGION WILL DOMINATE THE SYNOPTIC PATTERN
DURING THE LONG TERM PERIOD. CONTINUOUS SERIES OF WAVES WILL
PROGRESS NNE ALONG THE ERN PERIPHERY OF THE LARGER-SCALE AREA OF
TROUGH-O-GENESIS...MOVING ACROSS THE ERN GULF AND IMPACTING THE
PANHANDLE WITH PERIODS OF SHOWERS EARLY IN THE WEEK...AND THEN
STRATIFORM RAINFALL DURING THE LATER HALF OF THE WEEK. BRIEF LULL
IN PRECIPITATION MAY OCCUR TUE AND WED AS A RIDGE BUILDS OVER THE
REGION...BUT THIS WILL BE INTERRUPTED BY AN OCCLUDED FRONT MOVING
N ON THU. MODEL GUIDANCE SHOWS A RATHER MILD LOW-LEVEL AIRMASS
SPREADING N BEHIND THE THU FRONT...WHICH SHOULD YIELD HIGHS IN THE
LOW TO MID 40S ACROSS MOST OF THE PANHANDLE /THE EXCEPTION BEING
SKAGWAY AND HAINES...WHERE NLYS MAY LOCK IN SLIGHTLY COOLER
TEMPERATURES/.

INHERITED PRESSURE GRIDS WERE NUDGED TOWARD THE 12Z ECMWF...THEN
TRANSITIONED TO WPC BY DAY 4/WED. REMAINDER OF THE FORECAST WAS
UPDATED WITH AN ENSEMBLE BLEND OF WPC/ECMWF/GFS. PRIMARY CHANGES
OCCURRED WITH A REDUCTION IN POP/QPF TUE/WED...AND SLIGHTLY WARMER
TEMPERATURES DURING THE LATER HALF OF THE LONG TERM.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...STRONG WIND UNTIL MIDNIGHT AKST TONIGHT FOR AKZ027.
     STRONG WIND FROM 6 PM TO 9 PM AKST THIS EVENING FOR AKZ022.
     STRONG WIND UNTIL 9 PM AKST THIS EVENING FOR AKZ023.
MARINE...STORM WARNING FOR PKZ051-052.
     GALE WARNING FOR PKZ022-033-036-041>043.
     SMALL CRAFT ADVISORY FOR PKZ011>013-021-031-032-034-035-053.
&&

FERRIN/GARNER

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