Small Craft Advisory 42, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
604 AM AKST THU JAN 13 2011

.SHORT TERM...STRONG COLD HIGH PRESSURE IN THE INTERIOR OF
CANADA IS PROVIDING A STRONG PRESSURE GRADIENT AND COLD OUTFLOW
TO SUPPORT STRONG OUTFLOW WINDS ACROSS THE AREA AND EVEN A STRONG
TAKU WIND EVENT IN DOWNTOWN JUNEAU AND DOUGLAS. PEAK WIND GUSTS
REACHED 88 MPH AT SOUTH DOUGLAS LAST NIGHT, AND SOME REPORTS OF
DAMAGE WERE RECEIVED. HIGH WIND WARNING REMAINS UP AS CONDITIONS
STILL REMAIN FAVORABLE FOR MORE STRONG GUSTS INTO THE EVENING AND
OVERNIGHT HOURS. ELSEWHERE A HIGH WIND WARNING WAS HOISTED FOR
FOR THE ELFIN COVE AREA AS WINDS HAVE GUSTED AS HIGH AS 70 MPH
THERE TODAY. WIND ADVISORIES REMAIN UP FOR YAKUTAT, GUSTAVUS,
WRANGELL, AND HYDER DUE TO OUTFLOW WINDS OUT OF THE VARIOUS
INTERIOR PASSES, WITH MOST PLACES REPORTING GUSTS TO 40 OR 45 MPH
AT SOME POINT THIS MORNING. WINTER WEATHER ADVISORIES ALSO ARE
STILL UP FOR HAINES AND SKAGWAY FOR HIGH WINDS AND LOW WIND
CHILL. THOUGH FOR HAINES MOST OF THE HIGH WINDS AND LOW WIND
CHILL WILL BE ALONG LYNN CANAL.

 FOR THE MARINE ZONES, MOST INNER CHANNEL AREAS ARE EXPERIENCING
AT LEAST SMALL CRAFT ADVISORY WINDS AND TEMPERATURES ARE MAKING
THE POSSIBILITY OF FREEZING SPRAY VERY LIKELY WITH HEAVY FREEZING
SPRAY VERY LIKELY IN THE NORTHERN INNER CHANNELS. NORTHERN LYNN
CANAL AND CROSS SOUND ARE CURRENTLY BLOWING STORM FORCE WITH SOME
OF THE OTHER NORTHERN INNER CHANNEL AREAS BLOWING GALE OR SCA.

 THESE WINDS ARE EXPECTED TO CONTINUE TROUGH TONIGHT AND
TOMORROW. AS THE COLD HIGH IN CANADA CONTINUE TO BUILD SOUTH. THE
INGREDIENTS FOR THE TAKU WINDS NOT BE AS FAVORABLE BY THURSDAY
BUT WILL STILL HAVE THE POTENTIAL TO PRODUCE ADVISORY LEVEL GUSTS
THROUGH THE DAY. THE PRESSURE GRADIENT ACROSS THE AREA IS
EXPECTED TO DECREASE SLIGHTLY AS THE WEAK LOW THAT IS NEAR THE
CHARLOTTE ISLANDS WEAKENS AND MOVES INLAND THIS EVENING. HOWEVER
A SECONDARY LOW WILL BUILD BEHIND IT KEEPING THE GRADIENT HIGH
THROUGH THURSDAY. THE PRESENTS OF THIS SECONDARY LOW MAY ALSO
BRING A CHANCE OF SNOW LATE TONIGHT THE SOUTHERN OUTER COAST DUE
TO SE FLOW INTO THAT AREA.

 MODEL AGREEMENT WAS RATHER GOOD THROUGH THE SHORT TERM PERIOD.
DECIDED TO GO WITH A BLEND TO THE NAM WITH SOME OF THE LOCAL WRF
MODEL MIXED IN FOR WINDS TO INCORPORATE MORE OF THE LOCAL
EFFECTS. FORECAST CONFIDENCE IS GOOD FOR THE PERIOD.

 &&

.LONG TERM...LITTLE CHANGE TO FORECAST ELEMENTS IN THE LONG RANGE
FORECAST...AND THIS HAS RESULTED IN A HIGH WIND WATCH FOR THE
INNER ZONES NEAREST THE COAST MOUNTAINS AS WELL AS A WINTER STORM
WATCH FOR THE SOUTHERN PANHANDLE.

A SECOND WIND WIND MAXIMA IN THE ONGOING NORTHEASTERLY OUTFLOW
WIND EVENT IS EXPECTED ON FRIDAY. THIS IS BEING DRIVEN FURTHER
STRENGTHENING OF THE HIGH PRESSURE CURRENTLY OVER WESTERN CANADA
IN CONJUNCTION WITH DEEPENING LOW PRESSURE OVER THE GULF AS A 976 MB
STORM CURRENTLY SOUTH OF THE GULF NEAR 160W ENTERS THE SOUTHEAST
GULF ON FRIDAY. IN ADDITION TO HIGH WINDS...THE WARM FRONT ASSOCIATED
WITH THIS STORM WILL PRODUCE AN OVER RUNNING PRECIPITATION EVENT
OVER THE SOUTHERN PANHANDLE. THERE IS STILL A GREAT DEAL OF MODEL
SPREAD RELATED TO THE TIMING OF THE PRECIP SHIELD RELATED TO THIS
FRONT...BUT FORECAST CONFIDENCE IS HIGH ENOUGH TO ISSUE A WINTER
STORM WATCH FOR THE SOUTHERN ZONES. 48 HOUR SNOWFALL TOTALS IN THE
MORNING LONG RANGE FORECAST RANGE FROM AROUND 10 INCHES FOR THE
OUTER COAST TO JUST SHY OF 2 FEET NEAR HYDER.

FORECAST CONFIDENCE IS ABOVE AVERAGE FOR HIGH WINDS AND A
SIGNIFICANT SNOW EVENT FOR AT LEAST THE SOUTHERN PANHANDLE THROUGH THE
WEEKEND BUT ONLY AVERAGE FOR TOTAL SNOWFALL DUE TO MODEL SPREAD.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...WINTER STORM WATCH FROM FRIDAY MORNING THROUGH SATURDAY MORNING
     	 FOR AKZ026-028.
         WINTER STORM WATCH FROM FRIDAY MORNING THROUGH LATE FRIDAY NIGHT
	 FOR AKZ027.
	 WINTER WEATHER ADVISORY UNTIL MIDNIGHT AKST FRIDAY NIGHT FOR
	 AKZ018-019-025.
 	 HIGH WIND WATCH FROM FRIDAY MORNING THROUGH LATE FRIDAY NIGHT
	 FOR AKZ018-019-025-029.
	 WIND ADVISORY UNTIL MIDNIGHT AKST FRIDAY NIGHT FOR AKZ017-020-
	 022.
	 WIND ADVISORY FROM 9 PM THIS EVENING TO 9 PM AKST FRIDAY FOR
	 AKZ023.
	 WIND ADVISORY UNTIL 6 AM AKST FRIDAY FOR AKZ029.
	 WINTER STORM WATCH FROM FRIDAY EVENING THROUGH SATURDAY EVENING
	 FOR AKZ029.
MARINE...HEAVY FREEZING SPRAY WARNING FOR PKZ021.
	 HEAVY FREEZING SPRAY WARNING FOR PKZ021-022-034.
 	 HEAVY FREEZINGS PRAY WARNING FOR PKZ022-034.
	 HEAVY FREEZING SPRAY WARNING FOR PKZ011>013-031-032.
	 HEAVY FREEZING SPRAY WARNING FOR PKZ035.
	 GALE WARNING FOR PKZ011>013-021-022-031-035-043-051-052.
	 SMALL CRAFT ADVISORY FOR PKZ032>034-036-041-042.

&&

AHN/FRITSCH