202
FXAK68 PAFC 010101
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
501 PM AKDT Mon Jun 30 2025

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3: Today
through Thursday afternoon)...

Southcentral Alaska sits in a col between upper level ridging to
the northeast and southwest, and upper level lows to the
northwest and southeast. This will bring divergent weather across
the region through midweek.

For Kodiak Island and Southern Kenai Peninsula, the low to the
northwest will push in a very moist front by early tomorrow
morning. Satellite imagery currently shows precipitable water
values of over 1.5 inches as the front makes its way across the
Bering Sea. For Kodiak Island, 3-day rain totals could be around
2-3 inches as the front stalls overhead through Thursday. Southern
Kenai Peninsula will be on the periphery of this front, so skies
will be cloudy but rain amounts will be much, much lower.
Mariners transiting around the Barren Islands should beware of
winds to gale force tomorrow as the front moves through on Tuesday.

For the remainder of Southcentral Alaska, generally expect warmer
and more showery conditions (with isolated to scattered
thunderstorms) under the influence of both the ridge to the north
and the low near Southeast Alaska. For today, showers are
tapering off in the wake of an upper level shortwave that moved
across the region this morning. With skies clearing, warmer
surface temperatures are helping to promote convection. There is a
chance for isolated thunderstorms across the Copper River Basin
this afternoon and evening, though the overall likelihood is lower
due to the environment being tempered by the rain and fog from
earlier today. Tomorrow looks even less favorable for showers or
thunderstorms as the ridge nudges in and will likely suppress
convection.

By Wednesday afternoon, however, a robust shortwave diving south
from the Arctic will bring the highest chances for thunderstorms
so far this week. While instability does not look very impressive,
favorable upper level dynamics and storm motion could lead to
thunderstorms initiating along the northern Copper River Basin,
then moving southwestward. The footprint for these thunderstorms
could extend over much of the Copper River Basin, and perhaps even
reaching the Chugach Mountains to the south and west. Easterly
waves transiting across Southcentral on Thursday could also bring
afternoon and evening thunderstorms, but where these storms
initiate will depend on how far south the ridge to our north will
nudge into Southcentral, which will, in turn, will affect how far
south these easterly waves are displaced as they exit out of
Canada.

-KC

&&


.SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS (Days
1 through 3: Today through Wednesday night)...

A mature low pressure system in the Bering Sea is currently
pushing a strong front across Alaska`s west coast bringing gusty
southerly winds and moderate to heavy rain to the region. Abundant
tropical moisture associated with the system will allow continued
rainfall through tomorrow for Southwest Alaska. Rain continues to
linger across mainland Southwest through Tuesday evening with the
heaviest along the southern AKPEN as the low tracks to the
eastern Bering. The development of a triple point low to the south
of the AKPEN will continue to bring additional rainfall to the
AKPEN, Bristol Bay, and Southwest Alaska coast into Wednesday.

A ridge builds in behind the low across the rest of the Bering
with quieter weather across the Western and Central Aleutians
tomorrow evening as the Eastern Aleutians contend with northerly
flow and rain showers downstream of the ridge. Areas of fog are
likely to redevelop for the western Bering and Aleutians,
underneath the ridge.

&&
.LONG TERM FORECAST (Days 4 through 7: Friday through Monday)...

Starting off the long term is the presence of an upper high in
northern Alaska. This, combined with an upper low in the Gulf of
Alaska will allow easterly flow into inland areas of
Southcentral. This flow will allow for chances for showers and
thunderstorms in the Copper River Basin, and the Talkeetna
Mountains for the 4th of July. Easterly storm motion may allow
some of these showers and thunderstorms to stream into the Susitna
Valley. Southwest Alaska will have a large low in the Bering
slowly make its way eastward. Heavy rainfall will impact the
Eastern Aleutians and Alaska Peninsula with the mainland coast
seeing rain by Saturday. The low will stall out just off the
Kuskokwim Delta coast and will continue to send fronts eastward,
bringing heavy rain to the Southwest mainland for the rest of the
weekend and into Monday.

Southcentral will see some ridging build in on Saturday. This
will result in a drying and warming trend for the region. The
Copper River Basin, Talkeetna Mountains, and the Susitna Valley
will retain chances for thunderstorms despite the ridge. This
drying trend will not last too long as a front from the low in
the Bering will arrive on Saturday. Heavy rainfall is expected
first in Kodiak on Saturday afternoon, then at the Southcentral
coastline. Anchorage and the Mat-Su Valley may receive rainfall
from this front as well if it orients correctly. This scenario is
uncertain as model agreement is quite poor at this moment.
Additional weaker fronts push into the Gulf into Monday with the
potential for scattered rainfall.

-JAR

&&.AVIATION...

PANC...Mostly VFR conditions are expected through the TAF period.
Some lower clouds between 3000 and 5000 ft will linger through
Cook Inlet this afternoon, but should they move over the Terminal
this afternoon they will likely burn off. There`s a chance the
MVFR cigs from this morning will rematerialize between 9Z and 15Z
but increasing southeasterly flow will allow conditions to dry
and cigs to remain VFR through the remainder of the TAF period.
Light winds will persist, changing between southerly and westerly.

&&


$$

145
FXAK67 PAJK 010605 AAA
AFDAJK

Southeast Alaska Forecast Discussion...UPDATED
National Weather Service Juneau AK
1005 PM AKDT Mon Jun 30 2025

...Evening Update and 06z Aviation Discussion...
Minor updates were made to the forecast this evening. Winds along
Northern Lynn Canal have not been as strong as originally
forecasted. Winds near Eldred Rock and Taiya Inlet have diminished
and are now SW around 10 kts gusting to 15 kts. The other main
change to the forecast was an increase to where fog is expected
tonight. Forecast confidence has increased for widespread patchy
fog south of Frederick Sound. Some coastal areas, around Sumner
and Southern Chatham Strait, have already experienced reduced
visibilities down to a couple miles or less. Otherwise, the
forecast remains on track with continued light precipitation and
diminishing winds.

&&

.SHORT TERM...
Key messages:
- Precipitation and overcast skies continue for a majority of the
panhandle.
- A low remains near the eastern gulf as it weakens and moves
inland.

Details: A band of precipitation has moved north across the
panhandle as of early this afternoon. We are continuing to watch
this band as it increases precipitation rates to around 0.1 to
0.15 inch per hour rates as it moves over an area. This band of
precipitation has already begun to weaken leaving areas of light
rain across the panhandle. This light rain will continue into
tomorrow as the low in the eastern gulf weakens and moves inland.

A ridge developing over the gulf Tuesday will also help to move
the low inland. This ridge moves over the eastern gulf late
Tuesday into Wednesday. This will help to lighten rain rates on
Tuesday to a 60% to 70% chance of 0.1 inches in 6 hours. That
being said, an upper level low will help to continue that light
rain. Most of this rain will be focused on the central panhandle,
but no impacts are expected. Winds will remain light in the short
term with the daily increase in winds in N. Lynn Canal into
Skagway due to a thermal gradient.

.LONG TERM...Wednesday through Sunday...
We are looking for a pattern shift starting Wednesday as broad
low pressure over the eastern GULFAK weakens and weak ridging
starts to setup over SEAK. While a drier trend to the forecast
Wednesday into the weekend is expected, we won`t be rain free. The
weak nature of the ridge with periods of weak upper energy
ejecting out of the central GULFAK upper level low means that
scattered showers will still be around for Thursday and through
the 4th of July weekend. It should not be a washout and guidance
does not have any heavy precipitation through Saturday. We will
have to watch an approaching front moving east out of the central
GULFAK on Sunday. /Garmon

Temperatures at the end of the week begin to increase to near
typical values for this time of year with maximum temperatures in
the mid to high 60s. Low temperatures will remain in the low to mid
50s to end out the week.

&&

.AVIATION...
Widely varying flight conditions across the panhandle this
evening as weak surface low and occluding front push into the
southern and central panhandle with scattered showers.

Starting with the far northern panhandle TAF sites Haines, and
Skagway, anticipating best flight conditions through the period
with VFR conditions and CIGs AoA 5000ft, near calm winds overnight
increasing to near 15kts and isolated gusts up to 25kts through
Tuesday afternoon.

For TAF sites along the Icy Strait Corridor including Yakutat,
Gustavus, and Juneau, anticipating low- end VFR to upper end MVFR
flight conditions with CIGs AoB 4000ft and intermittent visbys
down to 3 to 5SM through Tuesday morning. Winds will be near calm
and variable overnight, increasing to around 5 to 10kts through
Tuesday afternoon.

For TAF sites along and south of Frederick south, including Sitka
and Petersburg southward, expecting flight conditions to remain
deteriorated overnight with MVFR or worse flight conditions
expected with CIGS and Visbys AoB 2500ft. Winds will be near calm
and variable with likely IFR to LIFR development overnight with
CIGS AoB 1000ft and areas of fog limiting visbys by Tuesday
morning. Expecting improvements to predominate MVFR conditions for
southern panhandle TAF sites by 22z Tuesday with winds increasing
to around 10kts or less.

&&

.MARINE...
Outside: As the low moves northeast into the panhandle, winds
along the gulf slight increase to 15 to 20 kts. The strongest of
these winds are near dixon entrance with wind gusts near 25 to 30
kts. These stronger winds will decrease tonight through tomorrow
before becoming 5 to 10 kts along the outside waters. The highest
waves are near dixon entrance at 5 ft with a period of around 10
seconds. Waves will also subside through tomorrow to near 3 ft.

Inside: As the low has moved northward, winds have changed
direction within the southern inner channels to become southerly,
with the central to northern inner channels remaining northerly.
As this low diminishes, wind directions across the channels will
become southerly by tomorrow afternoon. Tonight, the northerly
winds across N. Lynn Canal will be overcome by a thermal gradient
that will allow for southerly winds of 15 to 20 kts. This is
expected to occur near Eldred Rock to Taiya Inlet today and
tomorrow. Otherwise, the other windy area will be near Clarence
Strait. In Clarence Strait, southerly winds of 15 to 20 kts are
expected to continue before diminishing tonight into tomorrow, to
10 kts.

&&

.HYDROLOGY...
The Taku River is continuing to steadily rise as water from the
glacier dammed lake, Lake No Lake, along the Tulsequah Glacier
drains. The river will rise through the next 18 to 24hrs and crest
late Tuesday morning just below bankfull levels of 42 feet. A
Special Weather Statement has been issued for this event with no
flooding impacts expected. People who recreate along the Taku
River and Taku Inlet should remain aware of the rising water
conditions along with any debris floating down the river.

&&

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

&&

$$

SHORT TERM...EAB
LONG TERM....JG
AVIATION...NM
MARINE...EAB
HYDROLOGY...ABJ

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