Petersburg, Alaska 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

685
FXAK67 PAJK 060612
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
1012 PM AKDT Thu Jun 5 2025

.UPDATE...Refreshing the Aviation section after the 06z issuance.

&&

.PREV DISCUSSION...ISSUED AT 401 PM Thu Jun 5...

.SHORT TERM...
Key Points:
 - Rain showers continue diminishing tonight with a short break
   Friday.
 - Winds remain elevated near Skagway and Haines into Friday
   morning.
 - The next low pressure system enters the western gulf Friday
   into Saturday sending a front toward the northern panhandle.

Details: Rain has continued across the southern panhandle as of this
afternoon. This rain will continue to lighten and eventually a break
will begin into Friday before the next low enters the western gulf
Friday night into Saturday. This low will bring an associated front
toward the northern panhandle with the heaviest rain focused near
Yakutat. Rain rates will begin to increase for Yakutat late Friday
night, but the heaviest rates will not arrive until Saturday
evening.

Winds will remain elevated near Northern Lynn Canal into Friday
morning when they begin to diminish. This means that Skagway will
continue to experience sustained winds of 20 to 25 mph with both
Skagway and Haines receiving wind gusts of 30 to 35 mph into Friday.

.LONG TERM...
Key messages:
 - A gale force low moves into western gulf early late Friday into
   Saturday.
 - Associated warm front brings more rain focused on the northern
   panhandle Saturday into Sunday.
 - Drier weather on the horizon to start the week as a ridge builds.


Details: Overall little changes have been made to the inherited
forecast in the long range. EFI Tables still match with the northern
coast getting unseasonably wet with this weekend system, though any
precipitation impacts still remain light. A short period of
increased integrated vapor transport of 250 to 500 will be focused
on the northern gulf. This higher moisture will bring the heaviest
precipitation around the Yakutat area with total 24 hour QPF amounts
around 1.5 to 2 inches. Heaviest rain rates will occur Saturday
evening into Sunday morning. The rest of the panhandle will see
lighter rain with 24 hour rain totals around 0.5 to 0.75 inches for
the central panhandle and even less for the south. Other main
impacts with this low will be gale force winds with the potential of
storm force wind gusts. For more information on marine winds, visit
the marine section.

After the weekend system leaves the area, broad ridging will build
over the gulf allowing for a chance of drier weather over the
panhandle with areas of light precipitation. As for temperatures,
highs will be in the mid 50s with lows in the mid 40s near normal.
Upper 50s and low 60s may be possible, mostly in the southern
panhandle where more breaks in the clouds are possible. Stay tuned
for updates through the week.

&&

.AVIATION...

Mixed bag of flight conditions from VFR down to intermittent IFR
out there this evening as front exits the region. There is some
mid level dry air intrusion working across the central panhandle
that`s attempting to scatter things out, but not seeing nor
anticipating much in way of improvement moving into the evening
and overnight hours with saturated low levels as brief ridging
moving in aloft. Through Thursday night, expecting widespread CIGS
to drop further, AoB 4000ft, with potential for isolated IFR cig
development by 12z through mid Friday morning. Expecting reduced
flight categories mainly due to reduced CIGS, but can`t rule out
patchy dense fog development through early friday morning. Flight
conditions improve to predominate VFR moving into 20z to 23z
Saturday with CIGS AoA 5000ft and prevailing 6SM.

Winds for much of the panhandle, decreasing to 5kts or less
overnight and variable, outside of Skagway and Haines which will
see persistent elevated sustained winds 15 to 20kts with gusts up
to 20 to 30kts through Friday afternoon.

&&

.MARINE...

Outside Waters:

With the most recent system exiting the region, general west-to-
east flow will give around 10 to 20 kt winds in the eastern Gulf.
A gale force low will move through the western Gulf late Friday
into the weekend, with winds shifting out of the southeast and
increasing through Friday night. The front side of the low looks
to bring gale force winds to coastal waters, with further
enhanced surface winds near Cape Suckling due to the formation of
a barrier jet. For more information see the marine weather
statement. The winds will start to pick up late Friday night and
last through Saturday. Winds of 25 to 35 kt could linger into
Sunday for the outer coast as the low wraps up and moves
northward.

Inner Channels:

Southeast winds will be replaced by predominantly southwest winds
as a cold, dry air mass sweeps across the panhandle Thursday into
Friday. Expect a mostly unstable atmosphere with this passing,
meaning gusty conditions in east west facing channels, such as
Cross Sound, Icy Strait, Frederick Sound, and Sumner Strait. Areas
exposed to the gulf will have a much sharper wind shift, then as
the winds encounter the mountains, much of the energy will be
lost. Still expect a wind shift even into southern Stephens
Passage, but expect the shift to be somewhat more gradual.

Additionally, westerly wind aloft will generate leeside troughing
near Haines and Skagway, keeping lower pressure. Then, near Icy
Strait, pressure rises from the aforementioned westerly cold air
advection will cause a sharp pressure gradient. The result will be
prolonged strong breezes in Lynn Canal, mostly in the northern
section of the channel.

Late Friday into the weekend inner channel winds will have increased
winds once again. A front extending from the gale force low looks
swing through the area increasing wind speeds in the inner
channels to around 15 to 25 kts. Lynn Canal will be the exception
again where wind speeds will increase to near 30 kts with brief
gusts upwards of 40 kts late Saturday night into Sunday.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Small Craft Advisory for PKZ012-021-022-643-644-651-652-661>664-
     671-672.

&&

$$

SHORT TERM...EAB
LONG TERM....EAB
AVIATION...NM   UPDATED by Bezenek
MARINE...STJ

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