Ketchikan, Alaska 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

733
FXAK67 PAJK 191253
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
453 AM AKDT Thu Jun 19 2025

.SHORT TERM...Not much has changed in the forecast outlook for
Thursday. The weak surface low and associated broad upper level
low in the southeastern gulf get pushed out by an advancing ridge
in the central gulf through Thursday night. This doesn`t stop a
band of showers from rotating into the northern panhandle and Icy
Strait Corridor this morning, followed by the central and southern
panhandle through the afternoon. The ridge will influence onshore
flow which should help to clear skies for the entire panhandle by
Friday, starting with the northern panhandle through Thursday and
progressively getting more clear as the showers pass. Haze is
still possible for the northern panhandle as the easterly flow
from Canada continues. Only light to moderate rain is expected for
these showers, though periods of heavier rain could blow through
briefly with the influence of surface heating. Onshore flow will
become more enhanced through the afternoon as a thermal gradient
builds between the warm, sunny interior and the cooler gulf
waters. A very small shortwave trough aided by this thermal
advection has potential to spin up over the outer coast of the
panhandle and move north quickly, bringing elevated winds of up to
15 to 20 kts through the inner channels Thursday afternoon into
the evening. This will also bring sea breezes through the daylight
hours to coastal communities Icy Strait northwards.

With clearing skies allowing for maximum daytime heating as we
near the summer solstice, temperatures inland away from sea breeze
influence will reach the mid to upper 70s. Along higher
elevations of the Haines Highway, temperatures will reach around
80 degrees Thursday afternoon. A heat advisory has been issued for
these expected conditions.

Convection over BC continues to flow westward over the Coast
Mountains through the day, looking to be a very similar situation
to yesterday. The far northern panhandle will be experiencing very
warm temperatures alongside clearing skies and upper level
easterly flow, which all point to potential for at least
lightning-producing showers. Strong CAPE associated with a low
lifted index and a similar set up to yesterday influenced the
addition of a slight chance of thunderstorms through the afternoon
for the forecast. While lightning may not actually make it across
the border, potential will continue to be assessed throughout the
day.


.LONG TERM.../Friday through Monday/... Showers will begin
to decrease Thursday night into Friday morning as a surface ridge
approaches the panhandle from the west, pushing the weakening low
to the southeast. This ridge, accompanied by an upper level ridge
building over the Gulf on Friday, will help to bring drier
weather, clearer skies, and some higher temperatures into this
weekend. Models showing 850mb temperatures of between 10 and 12
degrees C moving into the area alongside this ridge, which will
bring us some warm air advection that will also aid in bringing
temperatures up. This warm air advection alongside the surface
ridging will bring some areas of the panhandle to over 70 degrees
for their highs this weekend, with the highest temperatures
looking to be Saturday afternoon and in the southern panhandle.
There are some higher (14- 15 degrees C) 850mb temperatures moving
along the border with British Columbia, though this will have
little impact on the panhandle outside of Dyea, which is expected
to see highs above 80 for the weekend. Temperatures will also be
higher due to the lack of cloud cover during Friday and the
weekend, resulting in likely even higher temperatures than the
models are showing due to the long sunlight hours and surface
heating. However, there is likely to be a marine layer that forms
along the coast and into some coastal locations (Yakutat, Elfin
Cove, Sitka, and parts of western POW in particular). This will
bring some overcast skies and decrease the high temperatures in
these locations Friday through Sunday. There is still a lot of
variability in temperatures for these areas as confidence isn`t
high on the exact timing or locations of the marine layer at this
time, but we expect at least some decreases in temperatures at
these locations due to the coastal impacts regardless.
Temperatures will then begin to decrease again Sunday into Monday
through the majority of the panhandle, with only Hyder looking
like it will stay warmer for longer.

The higher temperatures in the Yukon Territory and British
Columbia alongside their potential for some convective showers
later in the week may result in some risk for wildfires, which may
bring some haze in to Haines and Skagway. We have kept the haze
in for the first half of the midrange forecast for just Haines and
Skagway in anticipation of this, before the ridge moves more
eastward and begins to change the northeasterly flow to a more
northerly or northwesterly flow that might not allow smoke to flow
in the direction of the panhandle.

Winds look to stay on the lighter side over the region for the
rest of the week into the weekend. However, the pressure gradient
in the northern panhandle may tighten as the surface ridge begins
to move in while a low remains over Canada to the northeast, which
may bring some elevated winds to Lynn Canal on Thursday. Friday
into Saturday morning there will be some elevated winds along the
southern outer coast and coming out of Chatham Strait and Clarence
Strait as the ridge continues to push east while a low remains
over British Columbia, bringing some 15 to 25 kt winds as the
gradient tightens. These winds are not expected to last however as
the ridge continues to push eastward Saturday into Sunday, with
winds decreasing to between 10 and 15 kt off the coast Sunday into
Monday.

&&

.AVIATION...Aviation concerns still center on the rainfall and
lower ceilings from shortwaves moving in from Canada. This
morning, one shortwave is over the Icy Strait and Juneau area
where rain showers with ceilings down to 700 ft have been observed
over night. Elsewhere this morning VFR conditions are the rule,
except for Haines and Skagway where a lower 2500 ft deck has
settled in. Some very isolated shallow ground fog is showing up at
Yakutat, and Skagway as well this morning. Today the wave over
the north will move out into the gulf this morning, while a new
shortwave will move into the southern panhandle. Expect improving
ceilings across the north up to VFR while the south (particularly
around Petersburg south to just north of Ketchikan) will see
lowering ceilings down to MVFR or even IFR in some cases through
this evening. Then expect improving ceilings late tonight into
Friday as the easterly wave activity diminishes. Convective
situation is expected to mostly be the same as what we saw
yesterday with thunderstorms developing during the afternoon in
northern British Columbia that will try to be advected into the
northern inner channels. Most of these storms will likely lose
their intensity as they try to cross the coast mountains with the
best chance of lightning right along the international border from
Taku River north to White and Chilkoot Passes. Can not completely
rule out a stray lightning strike or two around Haines or Skagway
this afternoon or evening though. Mostly lighter winds expected
through Friday through some southerly winds to 15 to 20 kt at the
surface could develop this afternoon and evening near Stephens
Passage and Lynn Canal.

&&

.MARINE...
Outside Waters: Variable winds turning W and increasing to
moderate to fresh breezes (11 to 21 kts) through Thursday with the
ridge approaching in the gulf. Dixon entrance may continue to see
elevated winds through the day as the persisting low in the
southern gulf continues to spin up bands of clouds and
precipitation for the panhandle. Wave heights remain around 4 to 5
ft as a SW swell diminishes through Thursday evening.

Inside Waters: Generally light and somewhat variable winds with
calm waters for inner channels through early Thursday morning.
Onshore flow will increase as a ridge approaches through the gulf
through the day. Upper level easterly flow keeps bands of clouds
and scattered showers in the forecast for the southern panhandle
into Thursday afternoon, with some isolated thunderstorms possible
for Lynn Canal Thursday afternoon. Overall winds will remain
light, with light to moderate sea breezes developing in the
afternoon. This thermal heating will potentially blow a quick wave
of higher wind speeds up the channels this afternoon, though it
will diminish quickly.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Heat Advisory from 1 PM this afternoon to 7 PM AKDT this evening
     for AKZ319.
MARINE...None.

&&

$$

SHORT TERM...ZTK
LONG TERM....Contino
AVIATION...EAL
MARINE...ZTK/STJ

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