610
FXAK67 PAJK 132209
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
Issued by National Weather Service Fairbanks AK
209 PM AKDT Wed Aug 13 2025

.UPDATES...The previous forecast is still on track and little to
no changes were made with the latest forecast update.

Previous AFD:

.SHORT TERM...A marine layer has formed and has moved over
Yakutat, into Icy Strait to Gustavus, and into Sumner Strait to
around Port Protection. Sitka has mostly been spared of low clouds
or dense fog from the protection of Kruzof Island. Expecting to
see the typical retreat of the marine layer by 10 AM today.
We are also seeing some radiation fog from the dry, northwest flow
aloft near Petersburg and Wrangell, and this is, again, expected
to burn off in the morning hours. Mostly benign day weather wise
for the panhandle, aloft ridging shifting to SW, onshore, moist
flow. Therefore, increased cloud cover will move over the
panhandle layer in the evening. Regardless, daytime maximum
temperatures will be a bit warmer across the region, with many
areas reaching the low to mid 70s. This will also allow for more
localized afternoon sea breezes to develop, however these are not
expected to be particularly strong.

For information on ongoing flooding in Juneau, check out the
Hydrology section below and check out the latest flood statement
at weather.gov/juneau.

.LONG TERM.../ Thursday to Sunday / The ridge aloft is moving east
and closed low is forming in the bottom of the trough headed to the
Southeast gulf and eventually be Southwest of the Haida Gwaii by
Friday evening.  The track of the low will likely keep any of the
rain showers to the southern half.   As the low becomes more
vertically stacked, more showers will be moving from BC into the
southern and then central panhandle Friday and Saturday.

The afternoon and evening showers Friday and Saturday and possibly
summer doesn`t not include the stronger convection which would mean
the mention of thunder. Will watch this to see if it will be needed
to be added.

Temperatures Thursday overall at or warmer than normal, and the
southern panhandle cooling a bit as the clouds and rain spread in.
Northern section may be close to 70 degrees Friday.  Weekend highs
around normal highs.

&&

.AVIATION.../Until 12Z Thursday/...From light winds & clearing
skies giving good conditions for radiational cooling over a good
portion of the Panhandle, in addition to plenty of SFC moisture
in place over the region from recent heavy rainfall, areas of FG
are expected to continue into Wednesday morning before thinning
out via solar heating. FG anticipated to occur, once again,
Wednesday night as similar conditions will be in place. As for SFC
winds, they generally look to remain on the lighter side as the
pressure gradient remains relatively relaxed through the TAF
period under the ridge of high pressure that is building into the
region. As we have clearing skies over SE Alaska through the
period, some relatively enhanced afternoon sea breeze winds are
anticipated for areas prone to those. LLWS will remain benign
through the period.

&&

.MARINE...
Outside: With rising pressures in the northern and central gulf,
winds in the eastern gulf have shifted out of the NW and increased
to moderate to fresh breeze (11 - 21 knots). With very light SW
swell, wave heights continue to be around 6 ft. Expecting to see
the marine layer redevelop tonight, decreasing visibilities down
to below one mile

Inside: Looking at a lax gradient for most of the day today in the
inner channels, with winds dictated by daytime heating and sea
breezes. Only expecting Sumner Strait, Icy Strait, and Cross Sound
to increase in winds in the afternoon, but not expecting anything
higher than a moderate breeze. Special note to areas near the
mouth of Mendenhall River, as large trees and other debris
have been reported to be washing down the river.

&&

.HYDROLOGY...AT 7:15AM AKDT, THE MENDENHALL LAKE GAUGE CRESTED AT
16.65 FT WHICH IS HIGHER THAN THE 2024 PREVIOUS RECORD FLOOD
STAGE OF 15.99 FT. AS OF 1PM AKDT, THE MENDENHALL LAKE GAUGE WAS
AT 10.6FT AND FALLING. OTHER AREAS ALONG THE RIVER, LIKE THE
BROTHERHOOD BRIDGE GAUGE, HAVE ALSO CRESTED AS OF THIS MORNING. WE
WILL CONTINUE TO MONITOR LAKE AND RIVER LEVELS. MARINERS SHOULD
CONTINUE TO STAY AWARE NUMEROUS TREES AND DEBRIS HAVE BEEN
REPORTED IN THE RIVER AND HAVE WASHED DOWNSTREAM.

A Flood Warning for the release of Suicide Basin remains in
effect. USGS laser gauge data from Suicide Basin and Mendenhall
Lake levels indicate a sub-glacial release from the basin is
continuing.

Be aware that riverbank erosion, trees, & other debris floating
down the river have already been reported. Review the published
Flood Warning for more information, as that will be continuously
updated.

&&

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

&&

$$

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