Gale Warning 207, NWS Juneau, AK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
300 PM AKDT Mon Oct 15 2018

.SHORT TERM.../Through Tues night/ A strong front lies N-S
through the central Gulf AK. A warm front extends east over the
far NE gulf. Rain is confined to near these frontal systems so the
panhandle south of about Glacier Bay had a chance to dry out some
today after weekend rain totals of 10 to 15 inches north of Icy
Strait. Temps are mild in the 50s and even 60 degrees today in
sunny Metlakatla. Breezy conditions prevailed Mon... mostly 10-20
mph but gusts were as high as 35-40 mph along the NE gulf close
to the frontal systems and N Lynn Canal.

Forecast models today continue to be in fair agreement with each
other and show very little change from the existing forecast.
Slight adjustments to clouds and precipitation fields were made
blending in the national blend of models which helped depict
observed conditions. The strong frontal system currently in the
NE Gulf will shift eastward tonight and Tue. A long N-S band of
significant rains will move inland late this evening... east
across the Panhandle during the day Tues... and into the coastal
mountains by late afternoon. Even the dry southern Panhandle will
receive 0.25 to 0.50 inches of needed rain Tues night and early
Wed.

Storm force SE winds will impinge the NE Gulf coast Mon night as
well. Most of the outer coast will experience Gale force winds of
35 to 40 kts and Small Craft Advisory speeds of 25-30 kts will be
occurring with the front by the time it passes through the inner
channels during the day Tue. The wind fetch offshore is very long
into the N Pacific so there is plenty of wind momentum to generate
swell to 15 feet tonight and Tue. Wind speeds in general will
finally abate Tues night.

Flood Advisories over the N Panhandle verified in Juneau and
Gustavus with standing water and the land slide out the road in
Haines on Sun. Thanks to the weather spotters who volunteered info
of impacts in their area to us at the NWS office. Rain amounts
will be less on Tues than they were over the weekend.

.LONG TERM.../Wednesday Through Monday/...As of 10 PM Sunday
night, the primary focus of the extended forecast is a strong low
pressure system that develops over the Pacific and tracks into
the Gulf Thursday evening. The biggest impacts associated with
this low will likely be a band of storm force winds that develop
along the northeast Gulf Coast along the front. Additional marine
impacts will be seas building to around 25 feet by early Friday
morning over the central Gulf and near Cape Suckling. For the
Panhandle itself, it will be a windy day with heavy rainfall
likely at some point during the morning and/or afternoon hours
Friday. Many of the inner channels have the potential to reach
small craft level winds or higher with this system; Cross Sound's
forecast already carries gale force winds Friday morning.

For Wednesday and Thursday, precipitation will remain ongoing
over the Panhandle, but will be should not yield significant
accumulations compared with the abundant totals seen over this
weekend. Unfortunately, the exact timing of a "dry" period before
Friday's low tracks into SE AK remains difficult to predict, but
the southern Panhandle should see a dry period on Thursday.

On Sunday, another front will push northward into the gulf and
come ashore late in the day. While this system does not look as
strong as the Friday low, near gale or gale force winds are likely
over the gulf.

Confidence Wednesday and Thursday is only average with the exact
locations that dry out and the time of occurrence remaining
difficult to pinpoint. However, confidence is above average
regarding the low that impacts SE AK on Friday, its development
has been closely monitored for the past 3 nights leading to higher
confidence in trending the timing and intensity of the system.
For the following system that will impact the Panhandle late
Sunday or Monday, confidence slightly below average as operational
agreement is moderate; however, WPC cites large ensemble spreads
present in that system.

&&

.AJK Watches/Warnings/Advisories...
PUBLIC...Strong Wind from 1 AM AKDT Tuesday through late tonight for
     AKZ017.
MARINE...Storm Warning for PKZ051-052.
     Gale Warning for PKZ022-041>043-053.
     Small Craft Advisory for PKZ011-012-021-031>036.

&&

TA/JB

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