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FXAK67 PAJK 140347
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
747 PM AKDT Thu Jun 13 2024

.SHORT TERM...
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/Through Friday night/...Attention has been focused
on a developing easterly wave on satellite imagery today and it
appears very likely that showers will develop tonight and be
concentrated from east to west along the northern side of the Icy
Strait corridor, expanding north and south by late tonight.
Although there has been very little shift in the maximum PoP
values, precipitation totals have been decreased since yesterday
with 24 hour totals ranging from 0.25 to 0.62 inches in the lower
elevations and populated areas. At higher elevations on the ice
field north of Juneau, significantly higher values are forecast
with as much as 1.33 inches. Snow is likely at the start of this
event along the international border in the area of greatest
precipitation, but the snow level will rise over the next 24 hours
and contribute to snowmelt and runoff. The usual problem spots at
this time of the year, Montana Creek, Jordan Creek, the Chilkat
River, and the Taiya River will be watched closely. Close
coordination with the Alaska Pacific River Forecast Center has
already occurred and will continue. At this time, river rises are
expected, but flooding is not.

The easterly wave will also promote convective activity and
afternoon thunderstorms have been observed once again today over
British Columbia and The Yukon. However, a lack of daytime heating
and the cooling effect of the ice field will inhibit thunderstorms
south of Berners Bay. By tomorrow, daytime heating and less ice to
cross may allow for some thunderstorms near the border of the far
northern inner channels - the Klondike and Haines Highways.

This short term forecast will mark the end of the cooler than
normal daytime highs...at least for a little while.

.LONG TERM.../Through Tuesday night/...This extended range
forecast begins with a modest warm up that will persist through
the early part of the next work week. Also on the horizon is drier
weather with easterly wave showers being blocked for the most part
by the coast mountains. Northwesterly flow over the eastern Gulf
is expected to be no stronger than 15 to 20 kts and may produce a
marine layer along the outer coast. Meanwhile, partly cloudy
conditions are forecast through at least Monday night with winds
10 to 20 kts...strongest over Lynn Canal and Skagway. Headed into
the latter half of the forecast, guidance is starting to show a
return to more normal temperatures and the potential for above
normal precipitation. This will have to be watched over the
weekend and into next week to see if confidence in this idea
increases or not.
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&&

.AVIATION.../Through Friday afternoon/...CIGs and VSBY
occasionally falling below 3000/5 in showers over Southeast
Alaska through Friday afternoon. Light thermal turbulence remains
likely is locations that see significant breaks in the cloud
deck, but no meaningful mechanical turbulence or LLWS is
forecast.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...None.

&&

$$

SHORT TERM/MARINE...Fritsch
LONG TERM....JG/SF
AVIATION...JG

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