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FXAK67 PAJK 190538
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
938 PM AKDT Wed Jun 18 2025

.UPDATE...Updated to include the 06z TAF issuance

SHORT TERM...Convection over BC continues to flow westward over
the Coast Mountains following the synoptic pattern of the broad
upper level low and surface low over the southern gulf. For the
far northern panhandle, some of these showers have produced
lightning across the border in BC, but have not progressed
further. While lightning may have not crossed the border as of
this discussion, light rain showers have been persistently
streaming over the central panhandle for most of the day and will
continue to do so into the evening.

For the northern panhandle, the advancing ridge will exert its
influence and begin to clear out the higher clouds Thursday, while
the southern panhandle will see a last band of showers rotate in
from the north east interior bringing light to moderate rain
through Thursday evening. With the influence of the ridge, onshore
flow will become dominant and will be more enhanced during
afternoon hours as the thermal gradient builds between the
interior and gulf waters. While skies in the northern panhandle
will be more clear of clouds on Thursday, haze from wildfires in
BC will likely be noticeable. Sea breezes will be commonplace for
coastal communities for 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. For more information on the weather
pattern heading into the weekend, see the long term discussion.

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 over the next day or two will mainly be
focused on periods of lowered clouds and lowered visibility from
bands of rain showers from various easterly waves tracking through
the region.

Bands of rain showers continue to move across the panhandle
tonight, reducing ceilings and visibilities to MVFR with times of
IFR. Currently, heavier showers have continued near Sitka
reducing visibilities below 5 SM and bringing a low cloud deck
around 500 ft. Multiple locations across the central and southern
panhandle will have their share of lower ceiling and reduced
visibilities as these bands of rain pass. Late tomorrow morning
into tomorrow afternoon a more structured band will move over the
southern panhandle creating predominate MVFR conditions reducing
visibilities below 5 SM and ceilings below 3000 ft. After
tomorrow afternoon, precipitation chances decrease tomorrow
evening.

Meanwhile at Yakutat, VFR conditions will the rule of the day as the
clouds and rain are expected to stay to their east.

&&

MARINE...Outside Waters: Variable winds turning W and increasing
to moderate to fresh breezes (11 to 21 kts) through Thursday with
the ridge 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 gradually decrease
from nearly 7 ft to less than 5 ft as a SW swell diminishes
through Wednesday evening.

Inside Waters: Generally light and somewhat variable winds with
calm waters for inner channels through Wednesday. Exception is a
strong sea breeze in Taiya Inlet Wednesday afternoon and evening
with winds around 20 kt, which will diminish as diurnal heating
wanes. Onshore flow will increase as a ridge builds over the gulf
Thursday. Upper level easterly flow keeps bands of clouds and
scattered showers in the forecast for the majority of the
panhandle Wednesday night into Thursday, with some isolated
thunderstorms possible for Lynn Canal Wednesday evening. Overall
winds will remain light, with exception of light to moderate sea
breezes developing in the afternoon similar to Wednesday.

&&

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

&&

$$

SHORT TERM...STJ
LONG TERM....Contino
AVIATION...EAB
MARINE...STJ

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