Petersburg, Alaska 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

405
FXAK67 PAJK 130544 AAA
AFDAJK

Southeast Alaska Forecast Discussion...UPDATED
National Weather Service Juneau AK
944 PM AKDT Sat Sep 12 2026

.UPDATE...Aviation section updated for 6z taf issuance, and long
range section updated.

&&

SYNOPSIS...
Key Messages:

- Inner channel marine winds remain for the next few days, with
  afternoon sea breezes up to 10 kts expected.

- High pressure remains through the rest of the weekend with drier
  weather, partly sunny skies, and high temperatures in the mid
  60s to mid 70s.

SHORT TERM.../ through Monday night / High pressure remains over the
Gulf of Alaska and Northeast Pacific. Flow pattern runs along the
Central Gulf Coast and then southeast along and over the panhandle
region.

A short wave in the mid levels is moving southeast over the
panhandle, and should exit the area by Sunday morning, but this is
only spreading a few higher clouds across the area. The overall
westerly flow will continue for the next couple of days and appears
to be fairly zonal so rather progressive flow at mid levels. Small
troughs and or vorticity lobes moving through will create the
isolated cloud cover at the mid and higher level over the next day
or so. At the lower level there is a marine layer with tops to maybe
4000 feet along the NE gulf coast and then South towards Dixon
Entrance. Think it may push back into the Yakutat area and Cross
Sound possibly to the Gustavus area tonight. Could potentially reach
the outer island of Prince of Wales too. Patchy fog that may be
locally dense could be found under the marine deck.

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.

The general trend for late week and beyond is first a drying trend
for late week as surface ridging builds over the panhandle through
lingering onshore flow could mean that showers and clouds will be
still around. The latter half of next weekend is looking to be
rather active as a more substantial front is possible as the
strong upper low that is moving into Bering sea sends a front
across the gulf. We will be watching this feature as some guidance
is suggesting this front could be min gale force as it crosses the
central gulf and somewhat wet as well.

AVIATION.../Through 06Z Monday/... VFR conditions are likely to
continue to prevail through the TAF period with the exception of
the marine layer moving into the coast overnight. PAYA has already
seen CIGs sitting around 2,500ft through the evening. This marine
layer is expected to persist through the morning, until about
18Z, and the likelihood for fog to develop will remain increased
overnight. The expectation is that this marine layer could move
into PAGS and PASI and guidance is indicating the possibility for
lower CIGs in PAKW as well. The biggest point of uncertainty is
how the marine layer will impact these locations, but satellite
imagery is indicating that low clouds have already begun reaching
into Cross Sound. Otherwise, mostly clear skies light and
variable winds can be expected through the day Sunday with sea
breezes likely to develop. However, the pressure gradient is set
up to support northerly winds, so specifically in PAGY, winds
could remain northward in direction.

MARINE...
Outer waters: No major changes from the previous forecast, with the
persistent message of high pressure dominating the Gulf through
the rest of the weekend bringing winds generally out of the W-NW.
Places north of Cape Fairweather should see more of a westerly
component to the wind. Wave heights remain 4 to 6 feet along the
coast and outer water from the westerly swell moving through the
area. As the high pressure moves to the east, 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.

Inside Waters: High forecast confidence of no major inner channel
weather hazards through the weekend. A marine layer out in the gulf
is expected to redevelop near Cross Sound and encroach its way into
W Icy Strait and S Glacier Bay Sunday morning and begin to thin out
by the late morning further inland. Winds will remain light through
much of Sunday, outside the typical afternoon seabreeze influences.
As previously forecast, a wind shift out of the south has occurred
for the northern inner channels as of this discussion and is
expected to persist through the early evening hours before
weakening. Winds overnight are expected to become light and
variable, with some northerly component near Taiya Inlet from
interior drainage winds. A similar story is expected to play out
Sunday with winds picking up with developing sea breezes by the
afternoon and then gradual weakening overnight into Monday. For
Sunday overall winds will remain 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 back to calm and
variable. Wave heights follow suit to lightening winds, 0 to 3 ft.
Overall, will likely be a nice couple of days to get out on the
water heading into early next week.

&&

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

&&

$$

SHORT TERM...Bezenek
LONG TERM...EAL
AVIATION...AGP
MARINE...STJ

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