Gale Warning 513, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
159 PM AKST SUN DEC 18 2011

.SHORT TERM...MODERATE STRENGTH FRONT MOVING INTO THE PANHANDLE
FOR TONIGHT BRINGING MORE PRECIP AND WIND TO THE PANHANDLE. THE
PRE-FRONTAL WINDS AND PRECIP HAVE ALREADY REACHED THE PANHANDLE
WITH PRECIP OBSERVED AT JUNEAU AND SITKA NORTHWARD AND WINDS WITH
GUSTS TO 40 MPH OBSERVED AT YAKUTAT. TEMPERATURES AT THE MOMENT
ARE TOO WARM FOR ANY ACCUMULATING SNOW ANYWHERE EXCEPT FOR THE
HIGHER ELEVATIONS ALONG THE HAINES AND KLONDIKE HIGHWAYS. IN THE
MARINE ZONES, WINDS ARE ALREADY REACHING INTO THE GALE WARNING
CRITERIA IN THE OUTSIDE WATERS OF THE GULF AND SOME INNER CHANNEL
AREAS HAVE 25 KT SMALL CRAFT WINDS BLOWING AS WELL.

FOR TONIGHT AND TOMORROW, THE FRONT WILL CONTINUE ON ITS WAY
THROUGH THE AREA. PRECIP WILL CONTINUE TO MOVE IN THROUGH THE
NIGHT WITH SOME OF THE PRECIP BEING HEAVY AT TIMES. TEMPERATURES
WILL REMAIN TOO WARM FOR ANY SNOW THAT FALL TO ACCUMULATE. THE
EXCEPTIONS WILL BE UP ON THE HIGHER ELEVATIONS OF THE HAINES AND
KLONDIKE HIGHWAYS WHERE SNOW COULD ACCUMULATE UP TO 12 INCHES AND
HYDER WHERE LINGERING COLD AIR WILL ALLOW THE PRECIP TO FALL AS
SNOW AS WELL. WINTER STORM WARNINGS REMAIN UP FOR THE HAINES AND
KLONDIKE HIGHWAYS UNTIL MIDNIGHT TONIGHT. I AM ALSO ISSUING A
WINTER WEATHER ADVISORY FOR HYDER FOR LATE TONIGHT AND TOMORROW AS
I AM EXPECTING OVER 8 INCHES BY TOMORROW AFTERNOON THERE. PRECIP
SHOULD START CHANGING OVER TO SHOWERS STARTING TOMORROW FROM WEST
TO EAST AS THE FRONT MOVES THROUGH.

WINDS WILL ALSO BE A PROBLEM. I AM EXPECTING GUSTS UP TO 45 MPH
ALONG THE OUTER COAST THIS EVENING. THE WILL EXTEND TO THE
SOUTHERN ZONES LATER THIS EVENING AS THE FRONT CONTINUES TO THE
EAST. INNER CHANNEL AREAS MAY ALSO SEE A PERIOD OF HIGHER WINDS
THIS EVENING AS WELL. SOME ISOLATED AREAS INLAND MAY SEE STRONG
WIND CRITERIA WIND THIS EVENING AS WELL.

 MODELS TODAY WERE HAVING A BIT OF TROUBLE. THE EC AND GFS WERE A
BIT TOO SLOW WITH THE FRONTAL SPEED WHILE THE NAM AND UK WERE
RATHER CLOSE. DECIDED TO STICK WITH THE NAM FOR TONIGHT MIXING IN
SOME EC FOR THE AFTERNOON ON MON TO TRY AND AVERAGE OUT THE
DIFFERENCES THAT ARE STARTING TO SHOW UP THERE. FORECAST
CONFIDENCE IS A LITTLE ABOVE AVERAGE.

&&

.LONG TERM...NO MAJOR CHANGE EXPECTED IN SYNOPTIC PATTERN THROUGH
THE LONG TERM. A SERIES OF FRONTS WILL CONTINUE TO MOVE THROUGH
THE AREA. THE FIRST WILL BE DEVELOPING WAVE ALONG OLD FRONTAL
BOUNDARY THAT DEEPENS AS IT MOVES INTO SOUTHEAST GULF MONDAY
EVENING THAT WEAKENS AS IT PUSHES ACROSS CENTRAL SOUTHEAST ALASKA
MONDAY NIGHT. MODELS CURRENTLY SHOW WIDE RANGE OF SOLUTIONS ON THE
EVOLUTION OF THIS WAVE. EC IS DEEPEST AND FARTHERS NORTH WHILE EC
AND NAM ARE FASTER AND KEEP IT FARTHER SOUTH. CURRENT GRIDS HAVE A
DEEPER AND FARTHER NORTH LOW LIKE EC AND WILL CONTINUE WITH THIS
THINKING. MAIN DIFFERENCE WOULD BE WITH A FARTHER SOUTH TRACK
COULD ALLOW COLD AIR TO WORK BACK INTO CENTRAL AND TURN PRECIP
BACK TO SNOW. WILL HAVE CAA AT 85 FROM THE WEST BUT RECENT TRENDS
HAVE KEPT THIS A MIX OF RAIN SNOW FOR THE PANHANDLE.

WEAK RIDGING IS EXPECTED FOR THE PANHANDLE TUESDAY BUT WITH MOIST
BOUNDARY LAYER AND WEAK 500 MB TROUGH MOVING THROUGH WILL KEEP
SKIES MAINLY CLOUDY AND ISOLATED RA/SN SHOWERS.

A STRONGER FRONTAL BOUNDARY WILL SPREAD GALES TO THE EASTERN GULF
WEDNESDAY. A DEVELOPING LOW ALONG THIS FRONT WILL MOVE ACROSS THE
NORTHERN PANHANDLE WEDNESDAY NIGHT AND WILL LIKELY BRING A BURST
OF STRONG WINDS TO PANHANDLE WITH IT. PRECIP LOOKS TO BE IN
MODERATE RANGE WITH THIS SYSTEM WITH ONSHORE FLOW FAVORING RAIN AS
P TYPE ALTHOUGH WILL LIKELY START AS SNOW OR MIXED THROUGH INNER
CHANNELS. SHOWERS IN WESTERLY FLOW BEHIND THIS FRONT CONTINUES
THU-FRI.

ANOTHER STRONG SYSTEM IS EXPECTED OVER SOUTHEAST ALASKA NIGHT OF
THE 24TH OR ON THE 25TH BUT DETAILS DIFFER WIDELY BETWEEN GFS AND
EC. CURRENTLY CONFIDENCE WITH THIS SYSTEM IS LOW.

WITH LOW CONFIDENCE IN ANY ONE MODEL SOLUTION, OPTED TO MAKE NO
CHANGES TO GRIDS TODAY AND HOLD COURSE FOR A FRONTAL PASSAGE ABOUT
EVERY 2 DAYS WITH GALES FOR EASTERN GULF AND MIXED PRECIP FOR
INNER CHANNELS.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...STRONG WIND UNTIL 9 PM AKST THIS EVENING FOR AKZ027.
         STRONG WIND UNTIL 6 PM AKST THIS EVENING FOR AKZ017-022-023.
         STRONG WIND UNTIL MIDNIGHT AKST TONIGHT FOR AKZ028.
         WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 3 PM AKST
     MONDAY FOR AKZ029.
         WINTER STORM WARNING UNTIL MIDNIGHT AKST TONIGHT FOR AKZ018-019.
         STRONG WIND UNTIL 3 PM AKST THIS AFTERNOON FOR AKZ018.
MARINE...GALE WARNING FOR PKZ012-022-031-033-035-036-041>043-051-052.
         SMALL CRAFT ADVISORY FOR PKZ011-013-021-032-034-053.

&&

EAL/MM