Gale Warning 402, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
453 PM AKST FRI DEC 13 2013

.SHORT TERM...MULTIPLE ITEMS TO KEEP THE FORECASTER HOPPING.
OVERRUNNING SNOW EVENT FOR THE NORTHEASTERN PORTION OF THE
PANHANDLE. SNOWING FAIRLY SOLIDLY WITH HAINES SEEING AN INCH AN
HOUR ACCUMULATIONS RATES THROUGH THE AFTERNOON. REPORTS OF 7 TO 11
INCHES SO FAR FROM THE EVENT. SKAGWAY REPORTING AS MUCH SNOW...
BUT A STRONGER WIND IS BLOWING IT AROUND BETTER. WHITE PASS WILL
REMAIN IN NEAR WHITE OUT CONDITIONS FOR THE EARLY PART OF TONIGHT
IN THE SNOW AND BLOWING SNOW. SNOW LINE MOVED NORTH OF JUNEAU/GUSTAVUS
REGION AROUND 4 PM TODAY SO THIS ARE NOW RAIN. THE WINTER WEATHER
ADVISORY FOR SNOW AND POOR MOTORING CONDITIONS WILL CANCELLED WITH
EVENING PACKAGE.

 TEMPERATURES STEADY TO SLOWLY WARMING ACROSS THE PANHANDLE WITH
RAIN ATTEMPTING TO GET TO HAINES AND SKAGWAY BY MORNING.

 REST OF THE PANHANDLE IS RECEIVING LIGHT TO MODERATE RAINS WITH
TROPICAL MOISTURE THIS SYSTEM WAS CARRYING WITH IT.

 WITH THE LOW MOVING IN WITH MOISTURE CAUSING THE GOOD SNOWS OVER
THE NORTHERN PANHANDLE AND RAINS TO THE SOUTH. A VERY SOLID LOW
LEVEL JET (50 TO 70 KT) AT 850 MB PUSHING OVER THE SOUTHERN
PANHANDLE AND THIS SPREADING SOME RATHER GUSTY WINDS TO THE
COASTAL AREAS AND ACROSS SOME THE INNER CHANNELS. GUSTS OF 40 TO
55 MPH HAVE BEEN FAIRLY COMMON IN CROSS SOUND AROUND SITKA CAPE
DECISION AND INTO COASTAL PRINCE OF WALES AND CLARENCE STRAIT.
HYDABURG EVEN HAD A FEW GUSTS THAT WERE APPROACHING THE 70 MPH
RANGE. WINDS AT LINCOLN ROCK IN NORTHERN CLARENCE STRAIT ARE
GUSTING TO 65 KT THIS AFTERNOON. EXPECT THE GUSTY WINDS TO
PERSIST A FEW HOURS THIS EVENING AND TAPER OFF BY MORNING.

 A SECOND LOW OVER THE FAR SOUTHWEST GULF OF ALASKA WILL BE
MOVING INTO THE SOUTHERN/SOUTHEASTERN PORTION OF THE GULF BY
SATURDAY AFTERNOON.

 &&

.LONG TERM...LONG TERM FORECAST EFFORT WAS PLACED INTO THE EFFECTS
ASSOCIATED WITH APPROACHING SYSTEM FOR SATURDAY NIGHT. A NEW PACIFIC
STORM WILL TRACK CLOSER TO SE AK SAT AND SAT NIGHT. THIS WILL
RESULT IN WINDIER CONDITIONS SAT EVENING ESPECIALLY NORTHERN INNER
CHANNELS. AS DESCRIBED IN EARLIER DISCUSSION... THE PRESSURE
PATTERN ORIENTATION WILL FAVOR A VERY STRONG BURST OF WIND AS THE
FRONT GOES BY LATE SAT AFTERNOON AND SAT EVENING. I BOOSTED WIND
SPEEDS A BIT IN N-S CHANNELS... INCLUDING STORM FORCE WINDS IN
LYNN CANAL SAT NIGHT WHICH MARINE FORECAST HEADLINES DONT MENTION
YET. WINDS IN E-W CHANNELS STAYED THE SAME. REFER TO GRAPHICAL
FORECAST LINK ON WEATHER.GOV/JUNEAU WEB PAGE FOR A PICTORIAL
DEMONSTRATION OF WIND EVENT.

 PART OF THE REASON FOR THE STRONG ENERGY WITH THE SAT SYSTEM IS
THE WARMTH ASSOCIATED WITH IT AS IT LIFTS FROM WARMER LATITUDES.
SOUTHERN PANHANDLE TEMPS WILL APPROACH 50 DEGS SAT AFTERNOON.
CENTRAL PANHANDLE COULD SEE MID 40S. THIS WARM AIR MASS WILL
BRIEFLY LIFT SNOW LEVELS TO 6000 FT OVER THE SOUTHERN PANHANDLE
AND NEARLY AS HIGH AS WHITE PASS IN THE NORTH. ALL THE WHILE THERE
WILL BE PRECIPITATION SO EXPECT ABUNDANT LOW LEVEL RAINS.

 THE FRONTAL WAVE WILL LIFT INTO THE YUKON SUNDAY AND THEN
CONTINUE EASTWARD. UPPER LEVEL WINDS WILL GRADUALLY SHIFT FROM
WARM SW DIRECTIONS SAT TO COOLER NW DIRECTIONS BY MON AS FLAT
RIDGING BUILDS IN BEHIND THE LOW. THIS WILL LOWER THE SNOW LEVEL
AGAIN QUICKLY. AND SINCE NW FLOW HAS MORE OVER LAND TRAJECTORY
UPSTREAM... PRECIPTATION WILL GRADUALLY TAPER MON AND TUES. ALL
MODELS DEPICT STRONG W-NW JETSTREAM OF 100-150 KTS REMAINING OVER
SE AK THROUGH THE WEEKEND.

 MODELS OF CHOICE WERE THE NAM AND ECMWF THROUGH THE WEEKEND. VERY
FEW CHANGES OR ADJUSTMENTS WERE MADE BEYOND THAT FOR NOW. WITH WPC
USED AS GUIDANCE FOR EXTENDED PERIODS. POP/QPF UNCHANGED FROM
PREVIOUS FORECAST. FORECASTER CONFIDENCE IN THE SYNOPTIC PATTERN
FORECAST AND WIND EVENT SAT IS AT OR ABOVE AVERAGE.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...STRONG WIND UNTIL 9 PM AKST THIS EVENING FOR AKZ021-026>028.
         STRONG WIND UNTIL 3 AM AKST SATURDAY FOR AKZ022.
         STRONG WIND UNTIL MIDNIGHT AKST TONIGHT FOR AKZ023.
         WINTER STORM WARNING UNTIL MIDNIGHT AKST TONIGHT FOR AKZ018-019.
MARINE...GALE WARNING FOR PKZ021-022-033>036-041>043-051>053.
         SMALL CRAFT ADVISORY FOR PKZ011>013-031-032.

&&

BEZENEK/TA