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FXAK67 PAJK 300622 AAA
AFDAJK

Southeast Alaska Forecast Discussion...UPDATED
National Weather Service Juneau AK
1022 PM AKDT Sun Jun 29 2025

...Evening Update and 06z Aviation Discussion...
No major changes to the forecast this evening aside from minor
tweaks to wind directions and speeds for inner channels and
keeping increased winds for Skagway a tad bit longer. Through
tonight, anticipating overnight lows in the upper 40s to low 50s
and winds decreasing to 10mph or less with areas of fog possible
overnight. Widespread rain returns and overspreads the southern
panhandle through early Monday morning as a low traverses up the
eastern Gulf of Alaska, continuing northward across the rest of
the panhandle through Monday afternoon.

&&

.SHORT TERM...
Through tonight, there will finally be the downward trend of
precipitation in the northern half of the panhandle. With the
incoming developing system on Monday, dry, northerly air aloft
will sap away most of the available moisture. Haines and Skagway
have the highest chances of seeing some clearing late tonight.
This may extend down Lynn Canal down to the Juneau area, but there
is only around 30% chance to see some clearing.

While there is certainly some uncertainty on the overall track of
the Monday system, whether the surface low will stick around off
the coast of Sitka or move inland before dissipating, the results
of either solution are more clear. The warm front of precipitation
will move up the panhandle late Sunday night into Monday,
bringing moderate to heavy rain to the southern panhandle up to
around Petersburg. A shortwave moving along the upper level low
looks to bring some enhanced lift from both divergence ahead of
the shortwave and vorticity advection along the trough. This
combined with impressive warm air advection around 850 mb will
prompt enhanced lift from around 4 am to 10 am Monday. The upper
level trough looks to move up to around northern Lynn Canal by the
afternoon hours, but shearing effects from the mountains in the
inner channels will keep the low level advection minimal and
localized to the southern half of the panhandle. Therefore, in the
southern panhandle, in particular, around Ketchikan, Metlakatla,
and southern PoW, expect rates around 0.15 to 0.20 in/hr. Not
expecting any flooding from this event, due to the progressive
nature of the heaviest rainfall, limiting any impacts. That being
said, some reduced visibility from heavy rain is perfectly
possible.

There is still a dry air intrusion around 700-500mb expected
behind the warm front, which previously lead to the thought of
some gusty winds following up the rain. Fortunately, it does look
like CAA is largely detached from the dry air, which will limit
lapse rates for any significant CAPE. Therefore, no longer
expecting any gusty winds behind the front, due to the lack of any
significant forcing mechanisms.

.LONG TERM...
Continued colder than normal temperatures, widespread overcast
cloud cover, and precipitation look to continue for the panhandle
through Tuesday, though more breaks in the cloud deck and less
rain could be in store for the latter half of the week, including
the Fourth of July. A cold upper level low will remain stationary
through July 3rd, before being ejected E into British Columbia,
only to be swiftly replaced by another cold upper level low moving
in from the W. While there is fairly solid confidence in the
larger synoptic scale pattern over the state during this timeframe
as a result, the same cannot be said for smaller scale details.
In particular, the various upper level troughs moving around the
first 500 mb low, have much less confidence on timing, strength,
and placement, as does the potential for a weak ridge in the lower
levels to try and build in during the latter half of the week.
What is known into next week is chances for rain will broadly
remain in the forecast, though the potential for fewer showers
July 3rd through the end of the week will exist.

Highest confidence is in the Monday/Tuesday system. A low will
stall and decay into an open trough off the coast of the AK
through the day on Tuesday before the remnants meander into the
panhandle and disintegrate entirely on Wednesday. During this
time, expect wave of showers to rotate around the decaying low,
moving into the panhandle and delivering rounds of rainfall to
much of the area. By Tuesday night, shower coverage will be
diminishing as the remnant trough continues to weaken.

Beyond Tuesday, confidence rapidly diminishes, but what can be
said is that cloud cover will linger and chances of rain showers
will continue, albeit diminished from what was previously
anticipated. Operational guidance indicates the potential for an
easterly wave moving across the northern half of the panhandle on
Wednesday. Alongside the easterly wave, chances for showers will
linger through the latter half of the week, but in the lull
between the former upper level low (which will be ejected
Wednesday), and the arrival of the next upper level low,
confidence has begun to grow that weak low level ridging will
attempt to build in. Should this ridging be sufficiently strong,
shower coverage will diminish across the area, and some occasional
breaks (and marginally warmer weather) are possible Wednesday
through the end of the week.

&&

.AVIATION...
VFR to upper end MVFR flight conditions across northern panhandle
TAF sites this evening with Cigs AoA 4500ft. Moving southward
down the coast and towards the southern panhandle, flight
conditions decrease with IFR to MVFR flight conditions reported at
Sitka and eastward to Ketchikan with Cigs AoB 2500ft and
intermittent visbys as low as 2 to 4 SM.

Through tonight, not expecting much improvement for the southern
and coastal panhandle as a low in the eastern gulf tracks into the
area into early Monday. Worst flight conditions will remain
across the central and southern panhandle, predominantly MVFR to
IFR along and south of Frederick Sound with CIGS AoB 2500ft and
visbys as low as 3SM through Monday afternoon. As low tracks
inland, chance for LLWS near Annette island up to Ketchikan
Borough, but not high enough forecast confidence to include at 06z
TAF issuance for impacts at PAKT, southeasterly around 20kts near
2k ft. Winds should remain 10kts or less with some TAF sites
going near calm and variable through tonight, increasing to around
10 to 15kts with strongest winds expected at Skagway Monday
afternoon.

For northern interior panhandle TAF sites, better flying
conditions expected with general VFR to upper end MVFR conditions
to continue with CIGs AoA 3500ft through tonight, with widespread
rain returning along and north of the Icy Strait Corridor by 21z
Monday, lowest rain chances for Haines and Skagway.

&&

.MARINE...
Outside: Shortwave moving north through the eastern gulf has
produced SE winds of 20 to 30 kt off of Prince of Wales Island and
Baranof Island today which has produced wind waves of around 8 ft
in that area. There is a small SW swell of up to 3 ft with 9 sec
period present as well that is expected to persist through Monday.
The higher winds and seas will move north tonight weakening as it
goes. Mostly 15 kt or less of wind and seas 6 ft or less expected
for Sunday and Sunday night even with the new shortwave moving
into the SE gulf late Sunday night. There could be brief periods
of 20 kt winds off of Prince of Wales Island around the surface
low Sunday night into Monday, but it should only affect small
areas.

Inside: Southerly push of stronger winds will be moving north
through the inner channels tonight as the short wave currently
over the south moves north. Highest winds of 20 to 30 kt currently
over the southern inner channels, but it should reach the
northern inner channels with 20 kt southerly winds by midnight.
This is a speed up in timing compared to the previous forecast
with the higher winds now occurring tonight and Sunday morning
rather then midday Sunday. Inner channel winds should diminish
Sunday afternoon and remain mostly low through Sunday night.
Exception is Clarence Strait and around Cape Decision where winds
of around 15 kt or possibly 20 kt could be blowing late by Sunday
night from the new short wave moving in.

&&

.HYDROLOGY...
After rounds of heavier showers earlier this afternoon, elevated
water levels are receding and flood advisories for Auke Lake and
Montana Creek have been canceled this evening. Rivers within and
around Mendenhall Valley, Lemon Creek, and Auke Bay will remain
elevated near bankfull conditions, gradually decreasing through
Sunday night. Another round of rain is expected to push into the
southern panhandle early Monday morning, overspreading the central
and northern panhandle through Monday afternoon. Highest 24hr
forecast rainfall totals around 1.0 inch expected for Ketchikan
Borough and Annette Island through Monday night, decreasing in
amounts as you move northward towards the central and northern
panhandle.

&&

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

&&

$$

UPDATE...NM
SHORT TERM...NC
LONG TERM....GFS
AVIATION...NM
MARINE...NC
HYDROLOGY...NM

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