024
FXAK67 PAJK 140010
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
410 PM AKDT Sun Sep 13 2026

.SYNOPSIS...
Key Messages:

- High pressure continues through Monday with drier weather,
  partly sunny skies, and high temperatures in the mid 60s to mid
  70s.

- Inner channel marine winds remain light through Monday, with
  afternoon sea breezes up to 10 kts expected.

- Pattern change on the horizon as a weather system approaches
  late Tuesday, bringing a return of rain and elevated winds
  across the panhandle by mid week.

&&

.SHORT TERM...

Ongoing forecast remains mostly unchanged from its previous
iteration, with high pressure sitting over the gulf at the surface
and a modest ridge aloft. This ridge does look to have minor
disturbances moving along the NE gulf coast, which look to
provide some minor lift and cloud development, which look to
advect over SE AK later today and tonight. As such, not exactly
expecting similar, more widespread radiation fog conditions
tonight and tomorrow morning. That being said, the NE gulf coast
into Cross Sound could have some lower clouds and reductions in
visibility. Going into Monday morning, a proper shortwave
disturbance, as weak as it is, looks to move from the NW to SE
across the panhandle. May see some mild lift and drizzle
conditions with this passing shortwave, particularly in the
morning hours. In wake of the shortwave, looking to see a building
of the ridge aloft behind it, increasing its amplitude, and
clearing out skies once more.

Going into Tuesday, we have the beginnings of a stream of moisture
coming up from far south in the Pacific. As of now, it is
currently in line for the Aleutian to Anchorage area for today and
tomorrow, but this plume looks to wrap around the ridge, pushing
the high pressure southeastward, and bringing rain back to the
panhandle. Not expecting much impact from this round of rain, as
the anticyclonic flow the moisture is following does not lend
itself to strong lift dynamics, but could see some moderate rain
for the Yakutat area mainly in part to orographic lift. Going into
the midweek, however, there are signs that mesocyclones developing
along the moisture plume may help redirect and enhance moisture
going into the northern panhandle. Confidence is low at this time,
with no flooding concerns. More information in the long term
section.

.LONG TERM... /Tuesday through Sunday/
Upper level pattern is rather dynamic through the long range. It
starts out with a broad ridge of high pressure situated over the
Gulf of Alaska while a sharp trough is at around 180 longitude.
That trough will be advancing east through the start of the long
range period and will proceed to push the ridge east into Canada
by Thursday. Behind it more zonal flow takes over, but not for
long. An upper level low will be digging SE from Russia by the
weekend and will eventually anchor a broad trough stretching from
the Bering Sea to the Panhandle by Sunday.

This means that the forecast for the panhandle is rather dynamic
as well. It will start out rather quiet with the ridge over the
gulf initially keeping most precipitation at bay. However, that
ridge will be starting to flatten enough that flow turns more
onshore over the northern panhandle and precipitation starts to
return to the forecast. The rain is not expected to start in
ernest until Wednesday as a front works its way eastward across
the gulf. This front does have some tropical connections, but it
is moving eastward at a decent clip and looks like it will be
weakening as it goes. So while there may be periods of moderate or
heavy rain rates (especially for the NE Gulf coast), the rapid
eastward movement and weakening nature means that those rain rates
will not be over any particular area for long. Expected rain
totals for Wed look to be around 1 to 3 inches mainly from the
central panhandle Northwestward with the highest totals expected
along the NE gulf coast. This system will also bring some wind
with 25 to 30 kt SW winds possible in the gulf while the northern
inner channels will see a burst of southerly winds up to 30 kt
during the day Wednesday.




&&

.AVIATION...VFR conditions continue this afternoon as the marine
layer remains positioned off the coast. This has allowed for mostly
clear skies with the exceptions of some clouds to form just above
mountain tops which are visible from FAA weather cams. These
conditions are expected to continue through the rest of the
afternoon into this evening before the marine layer moves back in
along the outer coast. Current thinking is that the marine layer
will get close to Gustavus again tonight while Yakutat and Klawock
will likely see similar conditions to last night with lowered
ceilings and visibilities. Elsewhere, any clouds that move in will
keep aviation conditions likely in VFR. Confidence for most TAF
sites is moderate to high. One exception is Juneau where fog could
potentially form this evening and be more extensive than what was
experienced last night. This would take conditions from VFR
potentially down to LIFR.

&&

.MARINE...
Inside Waters: No major changes to the marine forecast in the
short term with fairly benign conditions continuing Sunday night
and into Monday. A marine layer offshore in the gulf is expected
to redevelop along the coast overnight, and once more encroach
into Icy Strait/S Glacier Bay and over Baranof Island. Periods of
dense fog cannot be ruled out for areas that were socked in Sunday
morning. Similar to today, fog and associated marine layer should
retreat through the late morning on Monday. Winds will remain
light through much of the day Monday, besides the typical
afternoon seabreeze influences, around 10 kt or less, with a
sporadic gusts to 20 kts for a couple hours in the afternoon
before quickly diminishing into the evening. Some higher winds are
possible in Clarence particularly along the Tongass Narrows in the
afternoon Monday, similar to today. Winds overnight are expected
to become light and variable, with some northerly component near
Taiya Inlet from interior drainage winds. Wave heights remain
ranging 0 to 3 ft into Monday.

Outer waters: Same story different day for the gulf waters with
high pressure dominating the Gulf into early next week bringing
winds generally out of the W-NW, with a developing southerly
component by Monday night with an approaching wave from the west.
Places north of Cape Fairweather should see more of a westerly
component to the wind overall as well. Wave heights remain 4 to 6
feet along the coast and outer water from the westerly swell
moving through the area. For Monday morning expect the marine
layer to redevelop and bring lowered visibilities for the
northeast coastal waters. As the high pressure shifts eastward
later on Monday, winds for the central and southern portion of the
gulf will increase to 15-20 kt while points north of Cape
Edgecumbe should see NW winds remaining around 10-15 kt.

&&

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

&&

$$

SHORT TERM...NC
LONG TERM...EAL
AVIATION...SF
MARINE...STJ

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