Gale Warning 279, NWS Juneau, AK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
537 AM AKDT Wed Nov 2 2016

.SHORT TERM...A weakening trof over the N will dissipate this
morning. A complex low pressure and frontal system will intensify
and move N into the SE gulf by late tonight, then weaken as it
moves into the NE gulf by late Thu afternoon. Models have shifted
W with low track and went with the 00z GFS as it was a good middle
ground compromise on the low track.

Main forecast concern will be wind. As complex low and occluded
front move N today, pressure gradient will favor an offshore flow
by this afternoon. Think winds with the occluded front will not be
too strong over most land areas this evening due to unfavorable
pressure gradient orientation, except for areas over the S that
favor E-NE winds. Those areas could see 20-25 mph winds this
evening. The strongest winds will be with one of the lows that
move into the SE gulf late tonight. Models show low level jet of
65-75 KT at 925 mb along the S outer coast by 12z tonight.
Pressure gradient will be more favorable for more widespread windy
conditions there late tonight, so went ahead and issued a high
wind warning for zone 27 for 09-15z tonight. Also put in strong
wind headline for late tonight and Thu for zone 28, and for Thu
for zone 23 as low moves past them. Some areas as far N as the
PAJN area could have a period of strong wind Thu afternoon but
main core of low level jet remains offshore so not as confident
with that. Will have storm force winds over the far SE gulf and
Clarence Strait late tonight into Thu morning, with 30-40 kt
winds for the remainder of the SE gulf and some of the central and
S inner channels Thu. The far N channels will remain N up to 30 KT
Thu morning then diminish during Thu afternoon.

Otherwise, showers with the trof over the N will be ending this
morning as the trof dissipates and low level flow becomes more
offshore this afternoon. Rain with the lows/front will spread into
the far S late this afternoon, then reach most of the remaining
coast and inner channels tonight. The PAYA area will tend to
remain out of the precip with the low due to strong offshore flow
tonight and much of Thu. there may be a transition to showers
Thu afternoon over the S but for now keeping precip wording as
stratiform. Only mention of snow will be over the higher
elevations of the far N, but not expecting accums to reach advy or
warning levels attm.

.LONG TERM...A very active weather pattern over Southeast Alaska
through the extended range. The low mentioned above will weaken
rapidly Thursday evening as it pushes inland over the northeast
gulf coast. A rapid transition from northerly to southerly winds
will occur over the northern inner channels as it does so. Another
strong front will lift north through the area on Friday with more
significant wind and rain. A second strong to potentially high
wind event over the southern panhandle will be possible with this
system. However, there remains important model differences in the
evolution of this system and any potential wave development along
the front. Expect this portion of the forecast to be fined tuned
over the next 48 hours as model agreement improves. The remainder
of the long range features a strong front affecting the area every
other day through the middle to end of next week. Strong
southerly flow will keep any frozen precipitation confined to the
higher elevations. Based upon coordination with the short term
forecaster, used the 00z GFS for updates.

&&

.AJK Watches/Warnings/Advisories...
PUBLIC...High Wind Warning from 1 AM to 7 AM AKDT Thursday for AKZ027.
     STRONG WIND from Thursday morning through Thursday afternoon for
     AKZ023.
     STRONG WIND from late tonight through Thursday afternoon for
     AKZ028.
MARINE...Storm Warning for PKZ036-041-042.
     Gale Warning for PKZ022-033-035-043.
     Small Craft Advisory for PKZ011>013-021-031-032-034-052.
     Small Craft Advisory due to Seas for PKZ051.
&&

RWT/TPS

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