Wind Chill Advisory 4, NWS Juneau, AK

398 
WWAK47 PAJK 142027
WSWAJK

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE JUNEAU AK
1127 AM AKST WED DEC 14 2016

AKZ018-150500-
/O.CON.PAJK.WC.Y.0004.161215T0700Z-161215T1800Z/
TAIYA INLET AND KLONDIKE HIGHWAY-
INCLUDING THE CITY OF...SKAGWAY
1127 AM AKST WED DEC 14 2016

...WIND CHILL ADVISORY REMAINS IN EFFECT FROM 10 PM THIS EVENING
TO 9 AM AKST THURSDAY...

* LOCATION...KLONDIKE HIGHWAY NEAR WHITE PASS.

* WIND CHILL VALUES...TO 30 BELOW ZERO.

* TIMING...TEMPERATURES WILL FALL THROUGH THE EVENING WHILE 
  NORTH WINDS INCREASE WITH GUSTS TO 40 MPH. 

* IMPACTS...AT THESE TEMPERATURES EXPOSED SKIN WILL DEVELOP 
  FROST BITE WITHIN 30 MINUTES OF EXPOSURE. BLOWING SNOW WILL 
  REDUCE VISIBILITY AT TIMES. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

AN ADVISORY MEANS DANGEROUS WIND CHILL TEMPERATURES ARE ALREADY
OCCURRING OR IMMINENT.

EXPOSED SKIN IN THE ADVISORY AREA WILL BECOME FROSTBITTEN IN
30 MINUTES.

THIS STATEMENT WILL BE UPDATED BY 8 PM AKST WEDNESDAY OR SOONER
IF CONDITIONS WARRANT.

&&

$$

962 
WWAK47 PAJK 150013
WSWAJK

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE JUNEAU AK
313 PM AKST WED DEC 14 2016

AKZ018-151215-
/O.EXT.PAJK.WC.Y.0004.161215T0300Z-161215T2100Z/
TAIYA INLET AND KLONDIKE HIGHWAY-
INCLUDING THE CITY OF...SKAGWAY
313 PM AKST WED DEC 14 2016

...WIND CHILL ADVISORY NOW IN EFFECT FROM 6 PM THIS EVENING TO
NOON AKST THURSDAY...

* LOCATION...KLONDIKE HIGHWAY NEAR WHITE PASS.

* WIND CHILL VALUES...TO 35 BELOW ZERO.

* TIMING...TEMPERATURES WILL FALL THROUGH THE EVENING WHILE NORTH
  WINDS INCREASE WITH GUSTS AS HIGH AS 40 MPH. WINDS WILL DECREASE
  AND TEMPERATURES WILL INCREASE THURSDAY ALLOWING WIND CHILLS TO
  WARM UP THROUGH THE DAY.

* IMPACTS...AT THESE TEMPERATURES EXPOSED SKIN WILL DEVELOP 
  FROST BITE WITHIN 30 MINUTES OF EXPOSURE. BLOWING SNOW WILL 
  REDUCE VISIBILITY AT TIMES. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

AN ADVISORY MEANS DANGEROUS WIND CHILL TEMPERATURES ARE ALREADY
OCCURRING OR IMMINENT.

EXPOSED SKIN IN THE ADVISORY AREA WILL BECOME FROSTBITTEN IN
30 MINUTES.

THIS STATEMENT WILL BE UPDATED BY 11 PM AKST WEDNESDAY OR SOONER
IF CONDITIONS WARRANT.

&&

$$

318 
WWAK47 PAJK 150727
WSWAJK

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE JUNEAU AK
1027 PM AKST WED DEC 14 2016

AKZ018-151600-
/O.CON.PAJK.WC.Y.0004.000000T0000Z-161215T2100Z/
TAIYA INLET AND KLONDIKE HIGHWAY-
INCLUDING THE CITY OF...SKAGWAY
1027 PM AKST WED DEC 14 2016

...WIND CHILL ADVISORY REMAINS IN EFFECT UNTIL NOON AKST
THURSDAY...

* LOCATION...KLONDIKE HIGHWAY NEAR WHITE PASS.

* WIND CHILL VALUES...TO 35 BELOW ZERO.

* TIMING...COLD TEMPERATURES AND STRONG WINDS WILL CONTINUE
  OVERNIGHT. WINDS WILL DECREASE AND TEMPERATURES WILL INCREASE
  THURSDAY ALLOWING WIND CHILLS TO WARM UP THROUGH THE DAY.

* IMPACTS...AT THESE TEMPERATURES EXPOSED SKIN WILL DEVELOP 
  FROST BITE WITHIN 30 MINUTES OF EXPOSURE. BLOWING SNOW WILL 
  REDUCE VISIBILITY AT TIMES. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

AN ADVISORY MEANS DANGEROUS WIND CHILL TEMPERATURES ARE ALREADY
OCCURRING OR IMMINENT.

EXPOSED SKIN IN THE ADVISORY AREA WILL BECOME FROSTBITTEN IN
30 MINUTES.

THIS STATEMENT WILL BE UPDATED BY 7 AM AKST THURSDAY OR SOONER IF
CONDITIONS WARRANT.

&&

$$

935 
WWAK47 PAJK 151511
WSWAJK

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE JUNEAU AK
611 AM AKST THU DEC 15 2016

AKZ018-151800-
/O.EXT.PAJK.WC.Y.0004.000000T0000Z-161215T1800Z/
TAIYA INLET AND KLONDIKE HIGHWAY-
INCLUDING THE CITY OF...SKAGWAY
611 AM AKST THU DEC 15 2016

...WIND CHILL ADVISORY NOW IN EFFECT UNTIL 9 AM AKST THIS
MORNING...

* LOCATION...KLONDIKE HIGHWAY NEAR WHITE PASS.

* WIND CHILL VALUES...TO 35 BELOW ZERO.

* TIMING...WIND GUSTS TO 25 MPH THIS MORNING COINCIDE WITH VERY
  COLD AIR ALONG THE HIGHER ELEVATIONS OF WHITE PASS. WINDS WILL
  DECREASE DURING THE DAY TODAY SO WIND CHILL VALUES WILL WARM
  SLIGHTLY ABOVE ADVISORY CRITERIA OF 30 BELOW.

* IMPACTS...AT THESE TEMPERATURES EXPOSED SKIN WILL DEVELOP FROST
  BITE WITHIN 30 MINUTES. BLOWING SNOW WILL REDUCE VISIBILITY AT
  TIMES.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

AN ADVISORY MEANS DANGEROUS WIND CHILL TEMPERATURES ARE ALREADY
OCCURRING OR IMMINENT.

EXPOSED SKIN IN THE ADVISORY AREA WILL BECOME FROSTBITTEN IN
30 MINUTES.

THIS STATEMENT WILL BE UPDATED BY 9 AM AKST THURSDAY OR SOONER IF
CONDITIONS WARRANT.

&&

$$

TA

105 
WWAK47 PAJK 151734
WSWAJK

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE JUNEAU AK
834 AM AKST THU DEC 15 2016


AKZ018-151845-
/O.EXP.PAJK.WC.Y.0004.000000T0000Z-161215T1800Z/
TAIYA INLET AND KLONDIKE HIGHWAY-
INCLUDING THE CITY OF...SKAGWAY
834 AM AKST THU DEC 15 2016

...WIND CHILL ADVISORY WILL EXPIRE AT 9 AM AKST THIS MORNING...

WINDS ARE DIMINISHING THROUGH THE MORNING RAISING WIND CHILL
VALUES ABOVE 30 BELOW ZERO BUT STILL REMAIN BELOW ZERO FOR
THE NEXT 24 HOURS.

THIS WILL BE THE FINAL STATEMENT ON THIS EVENT.

$$

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
329 PM AKST Tue Dec 13 2016

.SHORT TERM...Another cold dry day across the panhandle. There
are two factors affecting how cold places are today. The first is
lighter winds across the panhandle than what has been seen. In a
few locations this means that the overnight inversion has not been
broken keeping temps rather cold. The other factor is some mid to
low clouds that developed over the gulf and from around Chatham
Strait westward last night that didn't allow areas under these
clouds to cool off that much last night but they are not allowing
temperatures to warm up that much today either. The result is a
wide range of temps ranging from single digits in some areas of
the north to low to mid 30s along the southern outer coast.

Speaking of the clouds, some snow and rain showers have developed
out in the gulf due to along shore flow and the relatively cold
air aloft. None of this precip has come onshore yet and they are
mostly expected to remain offshore through the next 24 hours
(though the outer coast could still see a few flurries tonight and
early tomorrow). The clouds and precip will start to get pushed
offshore Wed afternoon as an upper trough drops down from the
Yukon and offshore flow increases.

Winds are rather light across the panhandle currently. However
there are still some gusts at Skagway, White Pass, and Taku Inlet
due mainly to cold air in Canada spilling over the mountain passes
and lingering pressure gradient right along the Coast Mountains.
These winds will begin to increase again tomorrow as a new shot of
cold air in the wake of the upper trough settles into the southern
Yukon. Northern Lynn Canal is expected to increase to gale force
by Wed afternoon with 25 to 30 kt in southern Lynn and northern
Stephens Passage. Freezing spray will also become an issue again
as winds increase but heavy freezing spray is not expected through
Wed. As for land areas, winds at Skagway and along the Klondike
Highway will also become gusty by Wed afternoon with some blowing
snow possible again. Decided to issue a strong wind headline for
the Klondike Highway Wed afternoon.

Forecast updates were mostly local effect changes for wind and
temperature. Used Nam for guidance today.

.LONG TERM...Transition from the cold and dry conditions to
increasing temps with developing snow and rain for the weekend as
high pressure ridge begins to break down and waves advance from
the west. Wednesday night and Thursday will still have cold temps
and strong northerly and outflow winds due to arctic high over
Canada and inverted trough extending over the panhandle. Strong
winds for Skagway with Gales over N Lynn canal will last at least
into early Thursday. Outflow and locations impacted by
mountain waves, downtown Juneau, will be breezy and thus slightly
warmer than the wind sheltered areas which will still be in the
teens to single digits.

The first in a series of waves moves into the northeast gulf
starting Friday. Still enough cold air in place for development
of an overrunning snow event, but as the wave progresses eastward
and then south it will lose some energy. Models were in fair
agreement for the timing and strength of this wave but continue
to have large spread depicting the next wave for Saturday. There
is more of a defined frontal boundary extending from a low in the
N Bering Sea with this feature. Another system will track in for
Sunday into Monday. This low expected to have a more southerly
track crossing the Aleutians initially, but large spread on final
track and if it goes into the AK interior or stays in the northern
gulf. One thing that is in better agreement between models is
that warm air will move in with these waves with snow levels
starting to rise above 300 ft. Thus precip will become more of a
rain-snow mix or for the far southern panhandle turning to mostly
rain. Initially the Friday wave could produce a few inches of
snow, but for now bit early to nail down any accumulations. Upper
elevations should still accumulate snow at least through Monday.

Early on used a blend of ECMWF/NAM to refresh grids out to Friday.
NAM have been more aggressive moving in precip for the Friday
with ECMWF the slowest, so went with a compromise for now. Later
in the period GFS has been more inconsistent than the ECMWF but
not sold on either operational model runs for exact depth and
timing. Used new WPC for the rest of the long range which went
more ECMWF ensemble. Forecast confidence initially starts above
average but then drops by Friday as the pattern changes.

&&

.AJK Watches/Warnings/Advisories...
PUBLIC...Strong Wind from Wednesday afternoon through late Wednesday
     night for AKZ018.
MARINE...Gale Warning for PKZ012.
     Small Craft Advisory for PKZ011-013-031-041-042.
&&

EAL/PRB

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