Gale Warning 227, NWS Juneau, AK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
255 PM AKDT Wed Oct 24 2018

.SHORT TERM...Forecast still appears to be on track today as a
storm force low continues to work its way up the eastern gulf
coast, and very little changes were made to the forecast for the
tonight through tomorrow night time period. Observations of gusts
up to 45 mph have already been reported this afternoon for
southern area sites, and some marine buoys in the area are
reporting sustained winds of 40 kt. Canadian buoy 46208 located
just west of Haida Gwaii is currently reporting a gust of 52 kt,
and with sea heights at 26 ft, the gust is more than likely acting
as the sustained wind representation. Rain coverage has also
increased north as the low continues to strengthen, with rain
being reported as far as Gustavus. Areas are beginning to lose
the offshore flow component ahead of the low. Winds will continue
to be the main threat tonight through tomorrow until the low moves
west of Cape Suckling by tomorrow afternoon. Storm force winds
are expected along the eastern gulf marine zones, and strong gales
40-45 kt will work their way through Chatham and Clarence Straits
this evening through tonight. All other inner channel marine zones
can expect 25 to 35 kt winds. High Wind Warnings concerning gusts
to 60 mph remain in effect for Zones 22, 23, and 27, which
include the cities of Sitka, Klawock, and Hydaburg. For many other
locations, gusts between 40 and 55 mph are expected.

Winds should begin to diminish throughout most of the inner
channels tomorrow and tomorrow night as the low tracks further
north and west. As cooler air wraps into the low as it matures,
instability will increase providing the opportunity for potential
thunderstorms beginning late tonight for eastern gulf waters and
areas in the southern panhandle, the possibility extending all the
way into Ketchikan and north into Sitka. This also means that
rain tonight will take on a more convective shower regime by
tomorrow, with more breaks in the precip possible by tomorrow
night. Temperatures tonight through tomorrow night will also be a
struggle to keep up with. Generally, highs will be in the low to
mid 50s and lows will be in the mid to upper 40s, a very weak
diurnal range due to precipitation and cloud cover. However, some
locations may reach their high temps overnight due to mixing from
the winds and possible downslope flow for certain areas.

.LONG TERM.../Friday through Wednesday as of 10 pm Tuesday/
Upper trof will extend from western AK into the Gulf of AK at
beginning of long range period. The trof will move slowly E during
the weekend as upper pattern becomes a bit more progressive. After
the weekend, the flow pattern becomes tricky as models differ on
placement of key shortwave features. At the sfc, looks like a low
or lows will head N into the gulf for the weekend, with important
model differences on track and strength of the low(s). Given the
differences, decided to stick with current forecast for the longer
term period.

One aspect of the longer range forecast that will need to be
monitored is the wind for the weekend. Models suggest the low(s)
will have at least gale force winds, but given the differences in
track, did not have enough confidence in where to boost winds.
Left in the 25-30 kt winds for that time frame for the gulf.

&&

.AJK Watches/Warnings/Advisories...
PUBLIC...Strong Wind from 10 PM AKDT this evening through Thursday
     morning for AKZ026.
     High Wind Warning until 10 PM AKDT this evening for AKZ027.
     Strong Wind from late tonight through Thursday afternoon for
     AKZ025.
     High Wind Warning from 4 AM to 10 AM AKDT Thursday for AKZ022.
     High Wind Warning from 7 PM this evening to 7 AM AKDT Thursday
     for AKZ023.
     Strong Wind from late tonight through Thursday morning for
     AKZ020.
     Strong Wind through Thursday morning for AKZ021.
     Strong Wind until 1 AM AKDT Thursday for AKZ028.
     Strong Wind Thursday afternoon for AKZ018.
     Strong Wind from Thursday morning through Thursday afternoon for
     AKZ017.
MARINE...Storm Warning for PKZ022-041>043-051-052.
     Gale Warning for PKZ012-013-021-031>036-053.
     Small Craft Advisory for PKZ011.

&&

Voveris/RWT

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