Petersburg, Alaska 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

604
FXAK67 PAJK 191756
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
956 AM AKDT Sat Jul 19 2025

.UPDATE...

&&

.SHORT TERM...Fairly quiet conditions continue across the
panhandle through the weekend. An upper level low traversing
across the area will help keep some cloud cover over much of the
area through the day on Saturday, but don`t expect any
precipitation to fall as a result given the lack of support in the
lower levels. A persistent marine layer may linger through much of
the day in some areas as well, aided by an inversion which will
last through Saturday. A strengthening ridge in the Gulf through
the weekend should ultimately start to break down the cloud deck,
and areas where cloud cover does break could see temperatures
rise above forecast highs for the day. Said forecast highs will
largely be in the 60s on Saturday and Sunday.

.LONG TERM.../Sunday through Thursday/...A surface high pressure
system in the southern Gulf of Alaska continues to build through
the week, stalling over the southwestern gulf due to broad upper
level ridging. This ridging will funnel more dry air over the
panhandle, continuing the warming and drying trend into the long
term. Multiple approaching shortwaves in the gulf attempt to
strengthen through the weekend which could increase chances for
light precipitation along the northern gulf coast, though all look
to break apart before reaching the outer coast. The surface
ridging continues to strengthen into early next week which will
clear out skies and tighten the pressure gradient, increasing wind
speeds along the gulf coast. By Monday afternoon, sustained winds
will increase to 20 kts going into cross sound, with highest
speeds reaching around up to 30 kts off the southwestern coast of
PoW. Gusts may reach 30 kts in Dixon Entrance. A tightening
pressure gradient will bring up wind speeds from the northwestern
gulf, and an ESE direction is conducive to gap winds coming out
from between Kodiak Island and the Kenai Peninsula. From this, the
central gulf can expect to see up to 30 kts of westerly winds
with wave heights reaching 13 ft through Tuesday. The consistent
NW upper-level winds help to pull a deep upper-level trough down
over the panhandle Wednesday afternoon. This will assist the
associated surface shortwave trough in strengthening to a weak,
closed low over the northern gulf coast, bringing precipitation
back into the forecast for Thursday.

Clearing skies will allow for a sea breeze to develop in some of
the inner channels, with winds potentially reaching 10 to 15 kts
near the water in Juneau, Haines, and Skagway. Stronger winds are
expected through Icy Strait and up Lynn Canal with this sea
breeze, peaking in the mid afternoon. This is also conducive to
marine layer development along the gulf coast which will bring low
clouds to coastal regions and pushing into Cross Sound.

High temperatures of between 13 to 15 degrees C at 850 mb with
areas of 16 degrees C and clearing skies indicate warmer surface
temperatures for early next week, raising for Monday and peaking
Tuesday. Interior regions of the panhandle will experience the
highest temperatures, with highs potentially reaching the mid to
high 70s and lows in the mid 50s. Max temp EFI values have stayed
consistently high Monday through Wednesday. NBM probabilities are
indicating a 60% potential of reaching 80 degrees in areas of
Skagway and Haines and an 80% potential in Hyder on Tuesday. These
are areas of known temperature biases for the NBM and other
models are only estimating around a 30% chance just for Hyder, so
confidence is very low on temperatures actually breaching 80.

&&

.AVIATION...

Not much change for the ongoing TAF issuance, with mid level
clouds over the area as expected. Some early breaks in clouds in
the Juneau area, much earlier than expected. Still expecting most
areas to break out into VFR conditions by this afternoon, even
along the coastline. Highest chances for significant breaks in
clouds looks to be the northern panhandle including Haines,
Skagway, and Juneau as a weak  No significant wind expected
across the panhandle, with only sea breezes in Skagway by late
this morning.

&&

.MARINE...Inside waters: Wind conditions are rather low with 15 kt
or less observed in most areas, and with the exception of Lynn
Canal, wind directions are mainly N or W. Not much change expected
over the next few days in the inner channels with mainly N and W
flow with speeds of 15 kt or less and seas of 3 ft or less. The
main exceptions will be areas with strong sea breezes, like near
Skagway, and Cross Sound, where 20 kt winds could be seen during
the afternoons and early evenings.

Outside Water: W to NW flow is the main wind direction in the
gulf today and that is mainly expected to remain the case for the
next few days. Highest winds are around 15 kt off Prince of Wales
Island and in the central gulf. Combined seas are around 4 ft
with most of that being a 3 to 4 ft SW swell of 8 sec period.
These conditions are not expected to change all that much through
the weekend as ridging settles into the gulf. Highest winds
(around 15 to 20 kt) will mainly be off the western coast of
Prince of Wales Island through the period.

&&

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

&&

$$

SHORT TERM...GFS
LONG TERM....ZTK
AVIATION...NTC
MARINE...GFS

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