453
FXAK67 PAJK 200605
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
1005 PM AKDT Sat Jul 19 2025

.UPDATE...Update for the 06z TAF package. Forecast remains on
track, with central panhandle clearing continuing. Southern
panhandle picking up some clouds overnight night that will clear
in the morning. Most locations VFR conditions.

&&

.SHORT TERM.../Through Sunday night/ Main concern in the short
range continues to be when the cloud cover will break up over the
panhandle. The answer to that varies depending on where you are.
The northern panhandle and NE gulf coast have seen clouds stick
around due to just enough onshore flow in the low levels of the
atmosphere. That is starting to change however. Satellite imagery
is currently showing some breaks developing over the larger bays
and channels of the north and a minor upper short wave is also
moving SE across the panhandle. This short wave will start to turn
flow more offshore into Sunday. This should allow clouds to break
up more, if not by this evening, then through the day on Sunday
though marine layer clouds will still persist near the outer coast
even into Sunday night.

For the southern panhandle, Clouds have already been somewhat
broken in coverage over the last 24 hours as low level flow there
has just enough offshore component to do so. Still a lot of
clouds remain over the eastern inner channels of the south as well
as Misty Fjords. The above mentioned upper level short wave
should help clear things out more overnight and into Sunday as it
moves through. Again marine layer clouds near the outer coast will
continue to be persistent though.

With the clearing that is expected, high temperatures across the
panhandle for Sunday are expected to be higher then what was
observed today. More mid 60s to 70s are likely. Stronger sea
breezes are also likely with the warmer temperatures on Sunday
afternoon and evening. Some of these could reach 20 kt in
localized areas. However, if cloud cover sticks around
temperatures could turn out lower and sea breeze winds could be
weaker.

.LONG TERM.../Monday through Friday/...A surface high pressure system
in the southern Gulf of Alaska continues to build through the
beginning of the week, slowly moving northwest. A broad upper
level ridge stalls over the central gulf, reinforcing the surface
ridge and helping sustain the high early in the week. This ridging
will funnel more dry air over the panhandle, clearing out skies
and tightening the pressure gradient, increasing wind speeds along
the gulf coast. By Monday afternoon, sustained winds will
increase to 20 kts going into cross sound and along the coast,
with speeds peaking Tuesday evening around 25 kts off the
southwestern coast of PoW. Gusts may reach 30 to 35 kts in Dixon
Entrance. A tightening pressure gradient will bring up wind speeds
from the northwestern gulf, and an ESE direction is conducive to
gap winds coming out from between Kodiak Island and the Kenai
Peninsula. From this, the central gulf can expect to see up to 30
kts of westerly winds with significant wave heights reaching 12 to
13 ft through Tuesday.

High temperatures of between 14 to 16 degrees C at 850 mb with
areas of 17 degrees C and clearing skies indicate warmer surface
temperatures for early next week, raising for Monday and Tuesday.
Interior regions of the panhandle will experience the highest
temperatures, with highs reaching the mid to high 70s and lows in
the mid 50s. Max temp EFI values have stayed consistently high
Monday through Wednesday. NBM probabilities have consistently
indicated a very high potential of reaching 80 degrees in areas of
Skagway, Haines, and Hyder, despite temperature observations
rarely surpassing the low 70s the past few days. These are areas
of known temperature biases for the NBM and other models are only
estimating around a 30% chance just for Hyder, so confidence is
very low on temperatures actually breaching 80.

Clearing skies and warming temperatures will allow for a sea
breeze to develop in some of the inner channels, with winds
potentially reaching 10 to 15 kts near the water in Juneau and
Haines, and 20 to 25 kts in Skagway. Strong winds are expected
through Icy Strait and up Lynn Canal with this sea breeze, peaking
in the mid afternoon. This is also conducive to marine layer
development along the gulf coast which will bring low clouds to
coastal regions and pushing into Cross Sound.

The consistent NW upper-level winds help to pull a deep upper-
level trough down over the panhandle Wednesday. This will assist
the associated surface shortwave trough in strengthening into a
disorganized, yet closed low over the northern gulf coast. The
northern panhandle can expect light rain Wednesday with minor
accumulations of 0.2 inches or less in 24 hours. The central and
southern panhandle will join in Thursday, with potential for light
precipitation continuing into the weekend.

&&

.AVIATION.../ 00z issuance / Slowly but surely, there is an
expanding area of clearing skies in the central panhandle in the
wake of a mesoscale low pressure moving south. Regardless of
clearing or not, conditions across the panhandle have lifted to
VFR for CIGs with a cloud deck AOA 3500 ft. Winds have begun to
kick in for Skagway as expected, and look to continue through the
evening.

Looking towards tonight, ridging aloft looks to strengthen
slightly, encouraging a lower marine layer for tonight. Along the
outer coast, expecting a cloud deck between 1500-2000 ft, which
looks to move into the outer coast TAF areas, as well as Gustavus
overnight. There is some guidance indicating LIFR CIGs for western
PoW, but would like to have more confidence before including that
into any TAF issuance.

&&

.MARINE...Inside waters: Relatively low wind conditions across the
inner channels this afternoon with mostly 15 kt or less of winds
(mostly from the N and W) and seas of 3 ft or less in most areas.
Over the next few days, seas breeze circulations will continue to
be the main concern with the stronger seas breezes (up to 20 kt)
expected Sunday and Monday afternoons and evenings, as
temperatures over land warm into the upper 60 and 70s, before
diminishing again overnight.

Outside Water: Rather light winds (10 kt or less) across the gulf
with very low seas (3 ft seas with a 2 ft S swell at 16 sec). This
is expected to change into Sunday as ridging over the gulf builds
and NW winds off Prince of Wales and Baranof Island increase in
response. Expect around 20 to 25 kt NW winds from around Cape
Fairweather southeastward from Sunday afternoon into Monday
morning. Seas off of Prince of Wales Island will also build in
response to the increased winds likely building to around 7 to 8
ft by Sunday night. Rest of the gulf will see lower winds (around
10 to 15 kt out of the W) and lower seas (6 ft or less) through at
least Monday.



&&

.HYDROLOGY...The warmer temperatures across the northern panhandle
expected from Sunday through Tuesday is expected to increase
melt water runoff from glaciers and any remaining snow at
elevation later this weekend and into early next week. This is
looking likely to increase river levels on the Chilkat River to
above minor flood stage by late Sunday night, and while there will
be daily fluctuations, the river may stay at or above minor flood
stage into early next week. A flood watch has been issued for the
Chilkat Valley for the possibility of minor flooding starting
late Sunday night.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Flood Watch from late Sunday night through Tuesday afternoon for
     AKZ319.
MARINE...None.

&&

$$

SHORT TERM...EAL
LONG TERM....ZTK
AVIATION...NC
MARINE...EAL
HYDROLOGY...EAL

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