Petersburg, Alaska 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

929
FXAK67 PAJK 221746
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
946 AM AKDT Fri Aug 22 2025

.UPDATE...Updated aviation discussion for 18Z TAF issuance...

Minimal updates have been made to the forecast. Icy Strait and
Southern Lynn Canal are experiencing slightly higher than expected
wind speeds, specifically by Rocky Island, resulting in a small
craft advisory until this afternoon.

&&

.SHORT TERM...A stacked low pressure system remains situated
in the Gulf, bringing some precipitation predominantly along the
coast from Baranof Island northward and cloud cover across the
majority of the panhandle this morning. As the front moves
through, two waves of precipitation will pass over the panhandle:
the first reaching Baranof Island and Sitka early in the morning,
and the next impacting Sitka in the afternoon to evening. As the
front moves northward during the day, it will impact Icy Strait
corridor and northward by the afternoon into tonight. The highest
PoPs and QPF amounts are expected for the coastline from Baranof
Island up near Cape Fairweather, with the areas expected to see
the most rainfall being Sitka and Elfin Cove. The rain totals
along this area are expected to be between 0.20 and 0.40 inches in
24 hours, though the rates will remain light. As the front moves
along the coast, it will not push very far inland to the east,
rather staying closer to the coast, leading to little to no
precipitation being expected southeast of Kake and Petersburg.
This area will also see some warm air advecting in from the south
during the day, leading to some warmer maximum temperatures in the
southern panhandle.

The low will weaken throughout the day and move to the Southwest
Friday night into Saturday morning, decreasing both precipitation
chances and winds across the panhandle tonight. The main area that
will continue to see elevated winds tonight into tomorrow will be 15
to 20 kt winds coming out of Cross Sound, but the rest of the
panhandle is expected to see much lighter winds moving into tonight.
The low moving out will allow for some offshore flow and clearing of
the skies, and alongside some warm air advection moving in will
bring some warmer temperatures for tomorrow.

Winds will be the main impact for this system still, with the
highest being along the outer coast and coming out of Cross Sound,
as well as parts of Icy Strait and Lynn Canal near Point Couverden.
For more information on the winds in the inner channels and outside
waters, read the marine discussion below. The only areas going into
this morning expected to see any fog development will be Yakutat
between 12Z and 16Z, with some places along Stephens Passage and
Frederick Sound potentially seeing some patchy fog with no real
restrictions to visibility expected.

.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...Stacked low remains anchored over the central Gulf of
Alaska with widespread VFR flight conditions across the panhandle
this early morning with CIGS AoA 6000ft and prevailing VIS 6
statue miles or greater. CIGs are beginning to drop in Sitka and
Gustavus through mid morning and into the early afternoon as a
frontal band extends into coastal Baranof Island. Juneau may see
some light impacts from this band as well, though VFR is still
expected to prevail for a majority of TAF sites. CIGS AoB 2500ft
are possible with reduced VIS from heavier showers, though current
guidance is leaning towards CIGs staying above 3000ft.

Winds should remain around 10kts or less, slightly increasing as
showers pass over. Haines is the exception to this, as outflow
winds in Lynn Canal ramp up to 15kts before decreasing through the
next few hours. Overland LLWS should remain benign through the
period, however, will see southeasterly LLWS around 25kts just off
shore along the Baranof Island coast by 20z through the rest of
the afternoon.

&&

.MARINE...
Outside Waters: A low rotating offshore in the Gulf is expected
to continue to bring predominantly strong breezes (22-27 kt), with
some potential for isolated near gales (28-33 kt) farther
offshore. Winds offshore will begin to diminish throughout the
day, particularly in the southern parts of the Gulf. The strongest
winds along the coast will be along Baranof Island up to Cape
Fairweather with expected fresh to strong breezes continuing into
this morning. Near gales will be possible near Cross Sound as the
front moves north by tonight and increases easterly winds. These
winds will begin to diminish tonight into tomorrow. Seas along the
outer coastline will continue to be between 6 and 9 ft, with the
highest being west of Baranof Island as the low moves north.
Offshore waters will remain seeing wave heights between 8 to 10 ft
today. Seas will diminish moving into tonight to between 3 and 5
ft. The low is expected to weaken throughout the day before moving
out of the area tonight into tomorrow morning. S swell expected
with dominant wave period of 8 to 10 seconds.

Inside Waters: As the low sits offshore and a front approaches
the coastline, the main impacts will be the east to west facing
channels and ocean entrances, which have seen increased winds this
morning. The highest winds will be coming out of Cross Sound, as
well as near Point Couverden by Rocky Island. Cross sound will
continue to see easterly moderate to fresh breezes between 15 and
20 kt throughout the day. Waters around Rocky Island will see
northerly fresh breezes around 20 kt today, which will diminish to
15 kt by tonight after the front moves through. Late tonight
winds across these areas will diminish into tomorrow. Winds across
the southern panhandle will stay relatively lighter, until late
tonight where Clarence Strait will begin to see some northerly
moderate breezes of 10 to 15 kt as an inverted trough begins to
set up along the west coast of B.C. to the south.

&&

.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.

&&

$$

SHORT TERM...Contino
LONG TERM...ZTK
AVIATION...NM/ZTK
MARINE...Contino

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