537
FXAK67 PAJK 171845 AAA
AFDAJK

Southeast Alaska Forecast Discussion...UPDATED
National Weather Service Juneau AK
1045 AM AKDT Thu Jul 17 2025

...Morning Update and 18z Aviation Discussion...
Forecast remains large on track this morning with only minor
marine wind adjustments needed. Main changes are increasing marine
winds in inner channels like Cross Sound, Icy Strait, northern
Lynn Canal, and for southern portions of Ketchikan Borough through
the afternoon. Not anticipating too much of an impact, with
strongest winds sustained around 15kts with isolated gusts up to
25kts and seas 3ft or less in the inner channels. Anticipating
intermittent and isolated drizzle and broken to overcast skies to
continue through early afternoon across much of the northern and
central panhandle as an upper level system pushes through the
area. With increased cloud cover, only forecasting high
temperatures to reach into the 60s for majority of the panhandle
by this afternoon.

&&

.SHORT TERM...
Key Points:
- A short wave moves over the panhandle today bringing clouds and
  light rain to the northern panhandle.
- Ridging continues behind the shortwave allowing for dry
  conditions to return for the weekend.

Details: Rain and low clouds have returned to Yakutat this
morning as a weak front and shortwave push into the panhandle.
This short wave is driven by an upper level low moving over the NE
gulf. This shortwave will continue to increase cloud cover this
morning, mainly for the northern panhandle. Light rain and drizzle
is expected today north of Frederick Sound. Rain totals remain
low below 0.1 inch for the entire panhandle.

Another ridge then builds over the gulf, moving into the
panhandle, Thursday afternoon into evening. This ridge will once
again create dry conditions across the panhandle into the weekend.
Times of lingering drizzle may continue into tonight due to
onshore flow over the far north.

Overall, no major changes were made to the previous forecast.
High temperatures remain in the mid 60s for the northern
panhandle, and high 60s to low 70s for the southern panhandle.
Clearing skies in the afternoon will once again allow for sea
breeze development, with the strongest of these winds near Skagway
around 15 mph.

.LONG TERM...
Stacked upper and surface high pressure situated over the Gulf
continues to last into the long range, continuing the warming and
drying trend into the weekend and early next week. There will be
some shortwaves attempting to move through Friday into Saturday,
bringing some chances for light rain along the northeast Gulf
coast, however the surface ridge will rebuild by Sunday. This will
bring a change to a warmer and drier pattern for early next week,
as skies will begin to clear Saturday into Sunday and rain
chances decrease for the majority of the panhandle by this
weekend. Alongside this ridging pattern, some significant 12 to 15
degree C temperatures at 850 mb will be advecting warmer air into
the region Monday and Tuesday and leading to some warmer surface
temperatures. This will be aided even further by the sky clearing
early next week, allowing for areas to get into the 70s for
maximum temperatures. Areas further inland and along the northern
panhandle (such as Skagway and Juneau) may see more of this warm
air advection, with the NBM showing a potential of 20-30% of
getting to 80 degrees and EFIs pinging for the panhandle Monday
and Tuesday. Overall something to keep an eye on in the extended
range.

The skies clearing will continue to allow a stronger sea breeze
to develop in some of the inner channels, with winds increasing to
10 to 15 kts if a sea breeze develops. With the setup of the
ridging offshore and a low over B.C., we are also expecting some
stronger westerly winds along Icy Strait and other E-W oriented
channels, with the strongest winds expected during the afternoon.
The outer coastline is expected to continue to see a pattern to
support a marine layer developing, with both the stacked ridge and
moisture availability, so areas along the coastline and into the
Icy Strait Corridor area if pushed inwards by westerly winds may
see some marine layer formation Friday into this weekend.

&&

.AVIATION...
Worst flight conditions remain along the coast this morning with
marine layer reducing flight conditions down to MVFR to isolated
IFR with CIGs AoB 2500ft. Elsewhere across the area, VFR flight
conditions prevail with CIGS AoA 4000ft under broken to overcast
skies. Through the rest of the afternoon, no major changes,
anticipating VFR conditions to prevail with CIGS AoA 4000ft under
BKN to OVC skies for the northern and central panhandle as an
upper level system pushes inland. For coastal TAF sites,
anticipating upper end MVFR to VFR conditions by 00z this
afternoon with CIGS AoA 2000ft as marine layer slowly moves off
shore. Best flight conditions will remain near Ketchikan through
the afternoon under a high level FEW to SCT cloud deck.

Winds should remain around 10 to 12kts or less through the
afternoon for much of the panhandle, outside of Skagway which will
see elevated sustained winds 15 to 20kts with sporadic gusts up
to 25 kts developing through early afternoon and into the evening.
Winds decrease to 5kts or less through late Thursday night, going
calm and variable. No LLWS concerns through the TAF period.

&&

.MARINE...
Outside: As a ridge behind the weak front moves into the
panhandle, winds along the coast will once again increase to WNW
15 to 20 kts. The strongest of these winds will be near Cape
Decision and into Dixon Entrance. Wave heights remain around 5 ft
building to 6 to 7 ft, for a short time this afternoon, west of
POW Island. Wave heights will then begin to subside this evening
with a 6 to 8 second wave period.

Inside: This morning, ahead of the next ridge, the inner channels
remain around 5 to 10 kts with isolated areas reaching 15 kts.
Late this morning the building ridge will increase the pressure
gradient first for the southern panhandle. This will increase
winds mainly in southern Clarence Strait and near Cape Decision to
around 15 kts. The ridge then approaches the N panhandle this
afternoon, and a tightening pressure gradient will allow winds
across Cross Sound, Icy Strait, and into Lynn Canal will increase
to 15 kts with gusts up to 20 ks. These stronger winds will
diminish late Thursday into Friday.

&&

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

&&

$$

UPDATE...NM
SHORT TERM...EAB
LONG TERM....Contino
AVIATION...NM
MARINE...EAB

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