575
FXAK67 PAJK 220556
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
956 PM AKDT Thu Aug 21 2025

.UPDATE...Updated 6z Aviation Discussion

&&

.SHORT TERM...
Key messages:
 - A low pressure system remains in the gulf sending a front
   toward the panhandle Friday.
 - Winds increase along marine waters with gale force wind gusts
   possible in the gulf.
 - The low pressure system weakens and move SW Friday night into
   Saturday morning.

Details: The low in the gulf continues to increase winds along
the outside waters through Friday. Winds along the eastern gulf
coast will increase late tonight into tomorrow as a front moves
toward the panhandle. As this front moves over the area, fresh to
strong breezes of 17 to 27 kts will move north through the gulf,
with the front. The strongest of the winds will be located west of
Baranof Island to Cross Sound. In these areas, winds will
increase to easterly 30 kts with times of 35 kt gale force gusts.
Winds along other inside channels and land areas remain lighter
with winds at or below 10 to 15 kts.

As this front moves toward the panhandle, cloud cover remains
high and rain chances return. Rain will remain light with the most
precipitation falling near the coast over Sitka to Elfin Cove
Friday. Rain totals remain low with a 40 to 50% chance of 0.5
inches falling in 24 hours. The low then dissipates and moves away
from the panhandle Friday night into early Saturday. Rain and
wind diminish at this time.

Fog continues to remain a concern over the eastern panhandle for
the next few nights. With light winds, partly clear skies, and a
saturated environment, fog development is expected during the
morning hours Friday and Saturday. Fog is likely to diminish
during late morning hours, but can continue to reduce visibilities
along land and marine areas for many hours.

.LONG TERM.../Saturday through Wednesday/...
Key messages:
- Ridging builds over the gulf Saturday into Sunday
- Sunny skies and above normal temperatures expected for
  this weekend into the start of next week

Details: Sunny, benign weather dominates the long range forecast.
The stacked low pressure system impacting the outer panhandle
Friday retreats into the central southern gulf and stalls for a
few days. Lingering precipitation in the central panhandle will
trickle out through the early morning hours of Saturday. Clouds
will dissipate as an upper level ridge begins to form, clearing
out skies across the panhandle by mid morning. This ridging
combined with high pressure in the central gulf will keep skies
clear through the weekend and into early next week.

This ridge will allow for clearing skies and warmer temperatures,
especially for the southern panhandle. Temperatures at 850 mb
increase to around 11 to 14 degrees C, even reaching 15 degrees C
for the interior southern panhandle. Those upper level
temperatures, with clearing skies, indicate temperatures
increasing into the 70s for many locations, and into the high 70s
in the southern panhandle. Outflow wind speeds will stay on the
lighter side around 5 to 10 knots. Some isolated areas of the
inner channels and Northern Lynn Canal may feel a sea breeze
attempting to develop, though this won`t get very strong with the
combating outflow winds. The only exception to this is into Cross
Sound, with the ridging helping to funnel sea breezes into the
channel. Areas away from the water will feel warmer, as light sea
breezes will provide a gentle breeze. A heat advisory has been
issued for Hyder through Saturday afternoon. These warmer
temperatures are expected to continue into early next week.

&&

.AVIATION...Little change to the tafs going forward, with said
changes limited to precipitation. Reduced the chance for vicinity
showers further inland as the likelihood of occurrence is less
than 20%. The front expected to spread over the gulf coast early
tomorrow morning was tightened up for duration of rain. Given the
lack of strength behind this front, not expecting a long lasting
rain event, with some brief MVFR CIGs along western Baranof Island
and visibilities down to 5 SM. With the incoming front is a fresh
injection of warm air aloft with upward motion. Because of these
southerlies, not expecting similar fog/low cloud development seen
in prior nights from mixing. Highest chance of occurrence will be
early this upcoming morning around the Juneau area down to
Petersburg. This is the lowest confidence portion of the forecast.

Otherwise mostly VFR conditions will continue through the next
TAF issuance.

&&

.MARINE...
Outside Waters: A low moving north in the Gulf is expected to
bring predominantly strong breezes (22-27 kt), with some potential
for isolated near gales (28-33 kt) farther offshore. The
strongest winds along the coast will be east of Baranof Island to
Cross sound. Along those areas, easterly fresh to strong breezes
will increase into Friday morning before diminishing Friday night
into early Saturday. Seas along the outer coastline will continue
to build into Friday to 6 to 9 ft as the low moves north. Offshore
waters will remain seeing wave heights between 10 to 12 ft
through Friday. The low is expected to weaken Friday before moving
out of the area Friday night into Saturday morning. S swell
expected with dominant wave period of 8 to 10 seconds.

Inside Waters: As the low approaches the coastline, the main
impacts will be the east to west facing channels and ocean
entrances, which will increase into tonight as the front reaches
the coastline. The highest winds will be coming out of Cross
Sound, as well as near Cape Decision coming out of Chatham and
Sumner Strait. Cross sound will increase to Fresh breezes with
easterly winds near 20 kts and wind gusts up to 25 kts. The
strongest of these winds will occur late Friday morning into
Friday afternoon before they begin to diminish into Saturday.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Heat Advisory from noon to 7 PM AKDT Saturday for AKZ331.
MARINE...Small Craft Advisory for PKZ643-644-661>664-671-672.

&&

$$

SHORT TERM...EAB
LONG TERM...ZTK
AVIATION...NC
MARINE...EAB

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