Gale Warning 113, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
333 PM AKST SAT FEB 15 2014

.SHORT TERM...VERY COMPLICATED SHORT RANGE FORECAST TODAY AS A
SLOW MOVING FRONT WITH A LOT OF WIND AHEAD OF IT WILL BE MOVING
THROUGH THE PANHANDLE TONIGHT. THE BIG STORIES WITH THIS SYSTEM
HAS BEEN THE SNOW UP IN HAINES AND SKAGWAY LAST NIGHT AND THE
WIND ACROSS THE PANHANDLE TODAY. DUE TO OVERRUNNING OF COOLER
AIR, THE HAINES AND KLONDIKE HIGHWAYS RECEIVED A DUMPING OF SNOW
WITH 14 INCHES TO OVER 2 FEET OF SNOW FALLING IN MANY PLACES OVER
NIGHT. THE SNOW HAS SINCE TAPERED OFF. AS FOR THE WIND, MANY
PLACES HAVE SEEN GUSTS TO 40 TO 50 MPH OVER THE COARSE OF THE
DAY. MARINE ZONES HAVE SEEN GALE FORCE WINDS MOST OF THE DAY AS
WELL.

 FOR TONIGHT THE FRONT WILL MOVE THROUGH THE PANHANDLE VERY
SLOWLY AND SLOWLY WEAKEN AS IT COMES. WINDS MOST PLACES ARE STILL
GUSTY BUT SOME PLACES ARE SHOWING A SLOW DIMINISHING TREND THIS
AFTERNOON. STILL HAVE STRONG WIND HEADLINES UP MOST PLACES THIS
EVENING AS I THINK THAT GUSTS UP TO 40 MPH ARE STILL POSSIBLE UP
TO FRONTAL PASSAGE. OTHERWISE WINDS WILL BE DIEING OFF AND
SWITCHING TO THE SW THIS EVENING AS THE FRONT MOVES THROUGH.
WINDS LATER TONIGHT AND TOMORROW WILL NOT BE THAT SIGNIFICANT AS
MOST PLACES WILL BE 20 KT OR LESS. WAVE HEIGHTS TODAY IN THE GULF
MADE IT UP TO 26 FEET AT DIXON ENTRANCE WEST BUOY AND THE CAPE
EDGECUMBE BUOY. THEY SHOULD DROP OVERNIGHT AS THEY LOSE THE HIGH
S TO SE WINDS THAT WERE SUPPORTING THEM.

 AS FOR PRECIP MOST PLACES ARE STILL WARM ENOUGH FOR RAIN. THE
ONLY PLACE THAT IS NOT IS SKAGWAY WHERE THEY HAVE HAD CALM WINDS
ALL DAY LONG. RAIN SHOULD INCREASE IN AREAL COVERAGE THIS EVENING
AS THE FRONT EDGES EVER CLOSER TO THE PANHANDLE. RAINFALL AMOUNTS
SHOULD BE ON THE QUARTER TO HALF INCH RANGE OVERNIGHT. BEHIND THE
FRONT SUBSTANTIALLY COOLER AIR WILL BE WORKING ITS WAY IN AND
WILL FORCE THE RAIN TO CHANGE TO SNOW LATE TONIGHT ACROSS THE
PANHANDLE. BY THIS POINT THERE WILL NOT BE THAT MUCH PRECIP LEFT
SO ACCUMULATION SHOULD BE IN THE 1 TO 4 INCH RANGE IN MOST PLACES
TONIGHT. TOMORROW SNOW SHOWERS IN THE COLDER AIR MASS WILL
DOMINATE THE WEATHER WITH THE NORTHERN PANHANDLE GETTING THE
BRUNT OF THE ACCUMULATION BUT EVEN THERE THEY SHOULD STAY BELOW
ADVISORY LEVEL.

 SHORT RANGE MODELS HAD SOME ISSUES TODAY. MOST MOS GUIDANCE WAS
ABOUT 3 TO 5 DEGREES TOO COLD FOR TODAY'S TEMPERATURES, AND THE
GFS AND NAM DID NOT INITIALIZE THE LOW ALONG THE FRONT TODAY VERY
WELL. THE MODELS ARE ALSO HAVING PROBLEMS WITH ANOTHER LOW ON SUN
AFTERNOON WEST OF HAIDA GWAII. DECIDED ON USING THE ECMWF AND THE
GEM FOR GUIDANCE TODAY AS THEY INITIALIZED FEATURES RATHER WELL
AND HAVE GENERALLY BEEN DOING WELL WITH SYSTEMS THIS PAST WEEK.

 &&

 .LONG TERM...THE UPPER LEVEL LOW OVER THE AK GULF AND EXTENDING
INTO THE AK INTERIOR WILL BE THE MAIN FEATURE THROUGH TUESDAY
WHEN IT WILL SHIFT NORTHEASTWARD AS A RIDGE OF HIGH PRESSURE
DEVELOPS OVER THE WESTERN GULF THEN BUILDS AS IT MOVES EASTWARD
THROUGH THE WEEK. WHILE THESE MID LEVEL FEATURES ARE SHOWING SOME
HIGH AMPLITUDES MODELS ARE INDICATING ZONAL PROGRESSION WITH NO
STABLE BLOCK FORMING. AT THE SURFACE A LOW WILL MOVE OVER THE
SOUTHERN PANHANDLE SUNDAY EVENING THEN PROGRESS NORTHWARD. THESE
SURFACE LOWS ROTATING UNDER THE UPPER LOW OVER THE GULF WILL KEEP
MOVING TOWARDS THE PANHANDLE. THESE LOWS SHOULD FOLLOW A PATTERN
OF DEVELOPING OVER THE SOUTHERN PANHANDLE MOVING NORTH AND
REFORMING IN THE NORTHEAST GULF. WHILE GETTING FAIR MODEL
AGREEMENT FOR THE SYNOPTIC PATTERN THROUGH MID WEEK STILL HAVE
LARGE SPREAD FOR SURFACE DETAILS. THIS TRANSLATES INTO SOME LARGE
SPREAD IN MODEL POP FIELDS. NAM/GFS ARE ON THE DRY SIDE
ESPECIALLY TO THE NORTH WITH ECMWF/UKMET KEEPING HIGHER POPS OVER
THE NORTHERN PANHANDLE THROUGH TUESDAY. THESE SYSTEMS ARE FAIRLY
WEEK, SHOWERY IN NATURE AND SHOULD NOT PRODUCE HIGH QPF VALUES.
TOWARDS THE END OF THE WEEK REMNANTS OF A SURFACE LOW IN THE
NORTHEAST GULF WILL BE PUSHED EASTWARD AS A SURFACE RIDGE MOVES
ACROSS THE GULF. BEHIND THE RIDGE IS AN OCCLUDED FRONT ASSOCIATED
WITH A LOW OVER THE ALEUTIANS, WHICH LOOKS TO REACH THE PANHANDLE
LATE FRIDAY INTO SATURDAY WITH STEADY PRECIP.

 COLDER AIR MOVES IN SUNDAY NIGHT AS WINDS SHIFT TO THE NORTH AS
THE LOW MOVES OVER THE SOUTHERN PANHANDLE AND THE GRADIENT
SHIFTS. MOVES OF THE PANHANDLE WILL HAVE SNOW FROM THESE SHOWERS
WITH THE COASTAL AND SOUTHERN PANHANDLE A RAIN-SNOW MIX.
STRONGEST WINDS OVER THE COASTAL WATERS AND INSIDE CHANNELS WILL
ONLY BE SMALL CRAFT AS THE GRADIENT BETWEEN THE SURFACE LOWS OVER
THE GULF AND AREAS OF HIGH PRESSURE OVER THE YUKON AND BRITISH
COLUMBIA IS WEAK.

 LIKED THE ECMWF/GEM INITIALIZATION WHILE THE NAM WAS TOO FAR
SOUTH. HOWEVER GEM BECAME AN OUTLIER EARLY ON AND THE GFS HAS
BEEN SHOWING SOME LARGE JUMPS RUN TO RUN. THERE WAS A LARGE SHIFT
BETWEEN THE 00Z AND 12Z ECMWF AS WELL WITH THE LOW POSITION,
WHICH HAD BEEN MORE STABLE. AS THE 12Z ECMWF CAME MORE IN LINE
WITH THE 12Z GFS DECIDED TO USE AN ECMWF/GEM BLEND INITIALLY THEN
TRANSITION TO AN ECMWF/GFS BLEND THEN FINALLY NEW WPC THROUGH DAY
8. HAVE LOWER FORECAST CONFIDENCE MAINLY DUE TO THE MODEL
INSTABILITY. FIELDS THAT SEEM TO CHANGE THE MOST HAVE BEEN POP
AND TEMPS.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...STRONG WIND UNTIL 6 PM AKST THIS EVENING FOR AKZ020>028.
MARINE...GALE WARNING FOR PKZ021-022-033-035-036-041>043.
         SMALL CRAFT ADVISORY FOR PKZ011>013-031-032-034-051>053.

&&

EAL/PRB