564
FXAK67 PAJK 070558
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
958 PM AKDT Sun Jul 6 2025

.UPDATE...06z Aviation Discussion Update

&&

.SHORT TERM.../Through Monday Night/...The current frontal system is
a bit stronger & more organized than we`ve seen, as of late,
which is continuing to progress through the Panhandle today, which
has increased rain coverage and is bringing some breezier
conditions to the Southeast Alaska region. Another low will
approach the Panhandle, riding up along the aforementioned front,
bringing the southern Panhandle more action with enhanced winds
and rainfall, late tonight through Monday. A widespread inch or 2
of rainfall is in store for the southern half to 2/3 of the
Panhandle for this system through Monday night. Also, notably,
there are slight chances for thunderstorms over the eastern Gulf
waters and along the Outer Coast over the next couple of days as
temperatures up at 850mb of as low as a little below 0 deg C, CAPE
values of up to around 150-200 J/kg, & positive vorticity values
up at 500mb advect toward and over those areas behind the front &
along with the low moving up from the south. SFC temps will remain
relatively seasonable for the short term forecast period.
Forecast confidence is average to above average as model guidance
is largely in good agreement on the attributes of the weather
features over the next couple of days.

.LONG TERM...
Key messages:
- Moderate to heavy rain continues Tuesday focused over the southern
  panhandle.
- A surface ridge allows for a decrease in precipitation Wednesday
  before the next system.
- Another low in the gulf brings moderate
  to heavy rain toward the entire panhandle Thursday into Friday.

Details: The front that moves over the panhandle Monday will
bring times of heavy to moderate precipitation focused on the
southern panhandle. A majority of this rain will fall Monday with
lingering showers into Tuesday. Total precipitation over Tuesday
remains around 0.5 to 1 inch of rain in 24 hours. A majority of
this will come from heavy rain Tuesday morning. Rain will then
begin to diminish Tuesday night into Wednesday as a ridge develops
between our two stronger systems. During this time, onshore flow
will continue allowing for times of light showers to continue on
Wednesday. Then a short break is looking probable Wednesday night
into Thursday as winds in the gulf shift out of the east with a
strong low approaching the central gulf.

Thursday into Friday, with the help of an upper level jet of SW
winds, a low will move into the northern gulf increasing winds and
bringing moderate to heavy rain. Currently, multiple ensembles are
showing the likelihood of >250 kg/m/s of integrated water vapor
transport moving over the panhandle. This supports the increased
chance of heavy rain across the entire panhandle, with the most
precipitation focused again on the southern panhandle. Along with
heavy precipitation, there is a >70% chance of gale force winds
along the NE gulf at this time. That being said, the active weather
continues for SE AK into and through this week. Stay tuned as we
will continue to update the forecast ahead of this system.

&&

.AVIATION...Very much a mixed bag of conditions for both CIGs and
VIS to start this taf issuance. Low dewpoint depression from the
recent frontal passage with slight ridging aloft has lead to
lighter wind over the land areas of less than 8-10 knots and some
misty conditions. Additionally, with the current moisture flow
aloft coming from the S to SE, areas that have mountains exposed
to the S to SE are generally having much lower CIGs, with heights
1100 to 1500 ft.

Unfortunately for much of the panhandle, in particular the
southern panhandle, these conditions look to deteriorate in the
coming hours overnight. A mesoscale feature moving up along
stronger jet aloft look to bring more WAA in the lower levels and
more moisture. Therefore, expecting CIGs to crash to IFR overnight
and into tomorrow morning. There will be an increase in winds for
areas exposed to the southeast, such as Ketchikan, but this does
not look to exceed 15 knots over land. Winds aloft to 2000 ft also
look to kick up, but did not include any LLWS as these winds are
mostly unidirectional, and do not look to exceed 30 knots.
Therefore, there is some speed shear, but not looking to exceed
criteria for LLWS.

&&

.MARINE...Inside Waters: The strongest winds on the inside are
expected to be 15-20kt during the day, but some higher gusts are
likely heading into the late afternoon and evening. A new low
center approaching from the southwest late tonight into Monday
morning will cause winds to increase to the Small Craft level
(25kt) for Clarence Strait. As the low weakens and passes over the
southern Inner Channels, expect winds to become light to 10 kt &
more variable in direction.

.Outside Waters: A low center set up over the northern Gulf and
an associated front are causing a barrier jet over the
northeastern Gulf near & southwest of Icy Bay through tonight.
Southeasterly winds will veer more southwesterly, then westerly
behind the front through the rest of this afternoon & through
Monday night, respectively. There is a slight chance of thunderstorms
across the northeastern Gulf this afternoon through the night.
Even if thunder does not develop, convective showers can make
their own gusty/erratic winds. Potential for thunderstorms shifts
to the southern half of the eastern Gulf Monday evening with the
new low center moving northward. Again, gusty/erratic winds and
choppy seas are all possible with those showers. Seas at the Gulf
buoys report 5-7ft, with a S-SE swell with a period of around 16
seconds. 6-8ft seas with the barrier jet small craft area are
anticipated to last through this evening.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Small Craft Advisory for PKZ036-644-651-652-661-672.

&&

$$

SHORT TERM...JLC
LONG TERM....EAB
AVIATION...SF
MARINE...JLC

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