Graphical Hydro Meteorological Discussion

650
FXAK68 PAFC 041341
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
541 AM AKDT Thu Jun 4 2026

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3: Today
through Saturday night)...

Expect another warm summer day today compliments of a ridge that
stretches across most of mainland Alaska. However, a weak shortwave
will skirt the Copper River Basin this afternoon and showers are
expected across the higher elevations this afternoon and evening.

For Friday, the upper ridge will weaken as a trough begins to dig
into Western Alaska out of an Arctic low. This will be enough to
increase shower activity over the Mountains for most of
Southcentral Friday afternoon and evening, though thunderstorms
are not expected.

Saturday will usher in a return to more clouds and increased chances
of rainfall due to the continued development of the trough.

&&

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

Key Messages:

* Red Flag Warnings issued for the Inland Bristol Bay and Lake
Iliamna zones from 1 PM AKDT this afternoon through 9 PM AKDT
this evening.

* A cooling trend, along with elevated minimum relative
humidities begins Friday and lasts into the weekend across
Southwest Alaska.

Discussion:

The dry and warm pattern will continue across interior Southwest
Alaska for today. Surface high pressure in the Bering along with
surface low pressure in the interior of the state will cause the
pressure gradient to tighten somewhat beginning this afternoon.
North to northwest winds of 10 to 15 mph with gusts up to 20 mph
at times are likely across Inland Bristol Bay (New
Stuyahok/Koliganek) as well as Iliamna and surrounding locations
this afternoon into this evening. These winds, in conjunction with
temperatures in the middle 70s and RH values in 20s percent will
present another hot, dry, and windy fire weather threat today.
With this, Red Flag Warnings have been issued for the Inland
Bristol Bay and Lake Iliamna zones from 1 PM AKDT this afternoon
through 9 PM AKDT this evening.

A cooling trend across Southwest begins Friday and lasts into the
weekend. Temperatures by this weekend look to drop back into the
low to middle 60s for highs. Shower chances return for portions of
Bristol Bay and the Kuskokwim Valley Saturday into Sunday as a
series of weak upper- level shortwaves will move overhead.

Farther out west, a weak North Pacific low will send its front
northward into Adak/Atka by Friday and will result in a period of
light rain. Rain should taper off by Friday evening across the
area as the front pivots back to the southeast. After the front
moves away from the Central Aleutian Chain, higher pressure builds
back in with more quiet weather anticipated across the Bering and
Aleutians through the weekend. The only challenge will be where
low stratus and overcast conditions develop.

&&

.LONG TERM FORECAST (Days 4 through 7: Sunday through Wednesday)...

Through the end of this weekend and into early next week,
relatively cooler and wetter weather is expected to roll in as
Arctic troughing gradually digs further south into interior
Alaska. As this occurs, northwesterly flow aloft will help
moderate temperatures closer to seasonal averages. While timing
these shortwave pushes remains the main challenge in the medium-
to- long range forecast, much of the southern mainland will likely
see on-and-off light showery conditions through the period.
Instability has trended lower, so convective activity should be
limited with any storms that do form.

Looking into the North Pacific, an upper-level low will track
across the Southern Gulf on Sunday and into Monday. While this
system shouldn`t have much direct impact on our region, it could
send moisture up into some of the coastal regions of Southcentral
(including the Wrangell Mountains and Price William Sound). By
Wednesday, another North Pacific low builds just South of the
Central Aleutians. This second low appears to take a more
northerly track, potentially bringing more widespread impacts
across the region toward the later half of the week.

-CW

&&

.AVIATION...

PANC...VFR conditions and light winds will persist.

&&

.FIRE WEATHER...

Surface high pressure over the Bering Sea coupled with surface low
pressure across the interior of the state will once again cause
north to northwest winds to increase this afternoon across
Southwest Alaska. The increase increase in winds will have a
drying effect across portions of the southwestern interior,
especially across Inland Bristol Bay where northwesterlies will
downslope off of the Kilbuck Mountains into Koliganek and New
Stuyahok. While temperatures across the majority of Southwest will
be a couple degrees cooler, temperatures are still expected to be
in the middle 70s across the interior. Relative humidities will
also look to fall to 20 to 25, especially for Lake Iliamna and
Inland Bristol Bay this afternoon. There is some uncertainty
regarding how much wind may reach into the Kuskokwim Valley and
along the Western Alaska Range (Lime Village) this afternoon,
which, in turn, also features uncertainty in how dry those
locations might become this afternoon.

For Southcentral: Hot and dry conditions will persist today,
before beginning to moderate for tomorrow. There remains the
potential for northerly winds up to 10-15 mph through the northern
Susitna Valley and northern Copper River Basin late this
afternoon through tonight. The strongest winds may also occur
during the overnight hours tonight. Therefore, it still looks like
the strongest winds and hottest/driest conditions will not line
up temporally or geographically as the strongest winds are also
expected to be through the higher elevations where conditions will
be slightly cooler and a little more moist.

In the end, there are NOT any Red Flag Warnings out for the
Susitna Valley or Copper River Basin, but conditions will not be
too far removed.

By Saturday, fire weather concerns will have abated across
Southcentral as an upper level trough digs into the area and
brings significantly higher RH values and lower temperatures.

&&

$$

971
FXAK69 PAFG 042338
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
338 PM AKDT Thu Jun 4 2026

.SYNOPSIS...

Quiet and dry conditions will continue across much of Northern
Alaska through the weekend, as colder conditions prevail along the
coast with warmer conditions farther inland. Increasing
northwesterly flow this weekend into early next week will lead to
temperatures broadly cooling to below seasonal norms, with
accompanying daily showers and isolated thunderstorms expected.

&&

.KEY WEATHER MESSAGES...

Central and Eastern Interior...

- Warm and dry conditions will continue across the Interior to
finish out the week, with highs reaching well into the 60s and
70s.

- Isolated showers are possible for the Alaska Range, Upper Tanana
Valley, and Forty Mile Country Friday afternoon/evening. These
isolated chances will expand across the Interior for Saturday
afternoon/evening, with isolated thunderstorms joining the mix.

- Gradually cooling temperatures are expected through the weekend
into early next week as increasingly scattered showers and
isolated thunderstorm chances build in starting Sunday through
midweek next week.

- Dependent on clearing skies, low temperatures Monday night
through Wednesday night will bottom out in the 30s and 40s for
most, with coldest valleys dropping to around freezing.

- Drier conditions are expected to build in Wednesday onward as
temperatures see a gradual rebound to finish out the week with
warming temperatures.

West Coast and Western Interior...

- Dry conditions will continue across Western Alaska through the
end of the week, with highs cooler on the coast in the
30s/40s/50s and warmer inland in the 50s/60s/70s.

- Strong west to northwest gusts Kotzebue Sound continue through
tonight with gusts up to 30 mph expected, gradually weakening on
Friday.

- Areas of low stratus and fog will continue along the West Coast,
particularly from the northern Seward Peninsula through the
Bering Strait to St. Lawrence Island.

- Very isolated showers will build in northwest to southeast on
Friday, with rain/snow showers and pockets of freezing drizzle
possible as conditions remain predominantly dry regionwide.

- Isolated showers will then continue through the weekend as
temperatures see a gradual cooling trend. Lows will be in the
20s/30s/40s.

North Slope and Brooks Range...

- Below normal temperatures are expected to continue into early
next week north of the Brooks Range with highs/lows in the
20s/30s while warmer air remains situated to the south of the
Brooks Range where highs in the 40s/50s/60s and lows in the
30s/40s continue.

- Isolated to scattered showers expected to continue across the
North Slope through Friday, expanding to the Brooks Range over
the weekend into next week. Light snow accumulations are
expected farther north.

- Gusty north/northwest wind gusts up to 30 mph will remain in
place over the Brooks Range and Eastern Arctic Coast/Plains
through tonight with winds gradually lessening Friday.

- Temperatures will hold steady or see a cooling trend this
weekend into early next week.

&&

.FORECAST ANALYSIS AND DISCUSSION...Today through Saturday Night.

Early afternoon satellite imagery shows a 510 dm low situated in the
Beaufort Sea, a 540 dm low in the Gulf of Alaska moving into
Southeast, and a 570 dm ridge of high pressure extending northwest
from the Aleutians and Southcentral/Interior to the Bering Sea. This
setup will continue to favor an overall quiet and dry setup for much
of Northern Alaska, with colder locations along the coast as highs
still trend well into the 60s and 70s farther inland. As the ridge
axis of high pressure in the Bering Sea weakens, the H5 low in the
High Arctic will push south with colder air and increasingly
scattered showers and isolated thunderstorms building in this
weekend into early next week. Farther south, another H5 low will
be moving east through the Gulf over the weekend, with some of the
energy working its way across the Upper Tanana on Saturday
bringing a slight chance for isolated showers and a thunderstorm
or two in the afternoon. Overall, quiet and predominant dry
conditions will continue across our region through the start of
the weekend with any precipitation remaining very light and
isolated in nature, ahead of changes on the way in the extended.

&&

.EXTENDED FORECAST DAYS 4-7...Sunday through next Thursday.

Thunderstorm chances briefly return to the Southern and Central
Interior on Sunday afternoon. Thunderstorms will remain scattered
and are most likely to form over terrain and move northeast into
valleys. Wind around thunderstorms will be gusty and erratic.
Rainfall accumulations in the Western Alaska Range may exceed a
quarter of an inch with these storms.

The arctic low will move into the Interior from the northwest across
the Northern Interior on Sunday into Monday. Temperatures are
expected to be well below average for the first half of next week
for a majority of the Interior and West Coast. Potential
frost/freeze products may be issued for the Fairbanks area for
Tuesday night as well as Wednesday night. Shortwaves spinning off
the low will bring snow, which at times may become mixed
precipitation for the North Slope and Brooks Range. These shortwaves
will bring gustier northwesterly winds on the Northwest Arctic Coast
from Sunday to Thursday. In the Interior, conditions will generally
be unsettled, with shower activity primarily expected on/around
terrain on Monday becoming more stratiform on Tuesday.

Model guidance starts to diverge on Wednesday. GFS models have
troughing remaining in place through the extended period, favoring
cooler and unsettled conditions. On the other hand, Euro models
favor a ridge building as it shifts from the Gulf of Alaska into
Southeast Alaska starting on Wednesday, which would bring a return
to summer-like weather.

Coastal Hazard Potential Days 3 and 4...None

&&

.FIRE WEATHER...

Warm and dry conditions continue across the Interior today with
highs well into the 60s and 70s as MinRH values drop into the
20-30% range. Wind gusts to around 15 to 25 mph are leading to
localized elevated to near critical fire weather conditions at
times, particularly across the Upper Tanana Valley out towards Tok
and Northway. Beyond today, fire weather conditions due to
wind/low RH look to dissipate as winds lessen. Outside of the
Interior, cooler conditions continue along the coast sas
precipitation chances remain scarce. Increasing broad
northwesterly flow will lead to increasing precipitation chances
over the weekend into early next week, with daily scattered
showers and isolated thunderstorms favored to develop. Cooler
temperatures will accompany this change in airmass, with
increasing humidities and areas of breezy winds at times.

&&

.HYDROLOGY...

Sagavanirktok River

Some overflowing is occurring; however, breakup along the Sag
River has not begun yet. Temperatures continue as below normal,
around the low 30s for a high near the coast and the mid to upper
30s for the northern Brooks Range. Going into the weekend and into
next week, much below normal to possibly record breaking
temperatures with lows possibly below 20 degrees and high
temperatures not exceeding freezing, except near the Brooks Range
where temperatures may reach the upper 30s. APRFC reports some
open water for the whole river channel.

Colville River

Fresh Eyes on Ice report from today shows between Umiat at Ocean
Point that the low is up slightly and is more turbid with fewer
but bigger jams present with a lot of stranded ice. APRFC reports
some open to mostly open water with mostly ice still in place by
Colville Village.

Please check weather.gov/aprfc for the latest breakup information.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...None.
PK...Small Craft Advisory for PKZ801-850.
Small Craft Advisory for PKZ804.
Brisk Wind Advisory for PKZ808-815.
Brisk Wind Advisory for PKZ809.
Brisk Wind Advisory for PKZ810.
Brisk Wind Advisory for PKZ814-855-861.
&&

$$

SYNOPSIS.......MacKay
KEY MESSAGES...MacKay
SHORT TERM.....MacKay
LONG TERM......Schlezinger/Troyke
FIRE WEATHER...MacKay
HYDROLOGY......MacKay

407
FXAK67 PAJK 041838
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
1038 AM AKDT Thu Jun 4 2026

.UPDATE.../to add the 18Z aviation discussion/...

&&

.SYNOPSIS...

Key Messages:

-Rain returns to the northern panhandle on Thursday, as a front
moves through

-Chances of showers linger into the weekend.

&&

.SHORT TERM.../Through Friday/...Rain is spreading northward as a
cold front slowly moves across the panhandle, with precipitation
likely to reach the Icy Strait Corridor by the afternoon hours.
Although PWATs of ~0.2 to 0.3 inches will help keep precip largely
limited to light to moderate, rainfall amounts of between 0.5 to
1 inch still look possible over the next 48 hours (through
Friday). The frontal band will stall over the Icy Strait Corridor
by Thursday evening before slowly sagging south and weakening
through Friday. Expect some chances of showers to linger even as
the front dissipates due to onshore flow as the parent low,
currently situated S of the panhandle, slowly moves off the E and
into British Columbia over the weekend. In its wake, a narrow
ridge will begin to rebuild across the eastern Gulf through the
weekend, for additional information, see the long term discussion.

Low temperatures will be moderated through the next few days, as
cloud cover keeps many areas in the upper 40s or the 50s during
the overnight hours. The cloud cover will also keep high
temperatures muted however, with high temperatures in the 50s and
60s becoming the default for the remainder of the week. Surface
winds will exhibit occasional breeziness and periods of more
gusty winds as frontal bands continue to advance north, though
given the distinct lack of strong dynamic support this far north
of the parent low, am expecting wind gusts to cap out for most
locations at ~20 to 25 kt, with Skagway being the exception which
could see stronger winds, as southerly flow is funneled through
Taiya Inlet.

.LONG TERM.../Saturday through Tuesday/...Surface ridging looks
to shift slightly south and east of the panhandle on Saturday,
with weak onshore flow allowing for light rain showers and cooler
temperatures. For Sunday onward, deterministic and ensemble
guidance widely varies between models and model run to run
differences with the handling of the next system traversing
through the Gulf. GFS and especially Canadian guidance favor
sliding the low south of Haida Gwaii, with drier offshore
conditions north across the panhandle. However, the GFS ensemble
trend has tracked a bit further north and more online with the EC
deterministic and ensemble guidance, which brings the low further
north into the eastern gulf with with multiple troughs/fronts
pivoting north through the panhandle. Have leaned towards the EC
solution and bring rain into the panhandle, although cap PoPs as
confidence in this solution is only moderate this far out due to
the large spread in model guidance. The best potential looks to
remain south of the Icy Strait corridor. Keep a chance of showers
into Tuesday, although the trend is looking to be drier as most
guidance has the low shifting southeast of the panhandle with
ridging building back in behind it.

Southeasterly flow looks to increase ahead of the low over the
weekend, possibly reaching small craft criteria along the outer
coastal waters and inner channels, especially into Clarence Strait
on Sunday. Seas also trend up in the eastern Gulf and ocean entrance
of the southern inner channels, possibly climbing to 10 ft. A
downward trend in marine conditions is expected early next week as
the low shifts off to the south and east.

&&

.AVIATION.../Until 18z Friday/...Bands of rain showers & lower
CIGs originating from an area of low pressure centered to the
southwest of the panhandle are continuing to move from south to
north over the Southeast Alaska region. This will continue on &
off through the TAF period. These bands will periodically lower
CIGs & VISs down to within the MVFR flight category through the
period. SFC winds will be on the rather breezy/gusty side through
this evening for the northern Lynn Canal(PAGY & PAHN) area,
especially for PAGY, due to a tightened north to south pressure
gradient in place over that area. SFC winds look to become a
little bit elevated for the PAKT area through this afternoon, as
well. LLWS values remain relatively benign through the TAF period.

&&

.MARINE...A low S of the panhandle will slowly move E into BC
through the remainder of the week. A remnant frontal band from the
low will linger over the panhandle before falling apart through
Friday. A ridge begins to build over the E Gulf over the weekend.

Outer Waters: Small craft advisory seas build over the southern
Gulf Thursday as a low S of the panhandle traverses E. Seas begin
to diminish by late Thursday night. By Friday, seas in the outer
coastal waters of 5 to 7 ft are expected. Seas will remain 5 to 7
ft until Sunday when wave heights build back to 8 to 10 ft. SW
swell of 2-4 ft on Thursday, with the largest swell in the
southern outer coastal waters. Swell diminishes to 1-2 ft on
Friday.

Inner Waters: Winds over the inner waters will fluctuate between
10 to 15 kt through the day, with wind speeds spiking upwards as
frontal bands move through. Lynn Canal and Clarence Strait will
likely remain on the stronger side, with these areas in particular
likely to see winds of up to 20 kt - or even 25 kt in the case of
the Clarence Strait ocean entrance.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Small Craft Advisory for PKZ036-641-661-662.

&&

$$

SHORT TERM...GFS
LONG TERM...DS
AVIATION...JLC
MARINE...GFS

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