469
FXAK68 PAFC 021319
AFDAFC
Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
519 AM AKDT Tue Sep 2 2025
.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3)...
Discussion:
The ridge that was over portions of Southcentral yesterday has
shifted east with the primary axis tilted NE to SW as a shortwave
moves up into interior Alaska. While the front has also shifted
east, it has once again stalled as the ridge prevents it from making
additional movement eastwards. This has shifted the main precip
axis eastwards as well...generally extending from Kodiak Island
towards the Copper River Delta. Behind the front, there are areas
of drizzle and light showers from the AKPen up through the Susitna
Valley. A low sitting off the coast of Washington and Oregon will
begin to retrograde back to the west, helping to squish the ridge
even more. The ridge will build back over portions of
Southcentral Wednesday in response to both the retrograding PacNW
low and a trough lifting north towards the southern AKPen out of
the north Pacific.
Once again, moisture transport will be focused in between the systems
with another round of rain moving up across Kodiak Island, Cook
Inlet, and Mat-Su Valley on Wednesday. More widespread rain will be
focused over the northern Susitna Valley where another inch of rain
is possible as the parent trough moves up towards the Kuskokwim
Delta.
- PP
&&
.SHORT TERM FORECAST SOUTHWEST ALASKA / BERING SEA / ALEUTIANS
(Monday to Thursday)...
Overnight rainfall is gradually shifting east of the region this
morning, though light showers are still falling from King Salmon
up into Iliamna. This activity should steadily diminish as the
remnants of a front/trough slide off to the east. Further to the
north, an upper trough is digging across the YK Delta with gusty
southerly winds ongoing across Nunivak Island and the Kuskokwim
Coast. Southwest winds gusting as high as 25 to 30 mph will likely
persist through midday before tapering off this afternoon. As a
result of the upper trough exiting Southwest into interior Alaska
and the remnant front/trough pushing east of the Western Alaska
Range, the second half of Tuesday is expected to be relatively
pleasant with dry weather and light winds. Cloud cover is more in
question, though it is likely that many areas across Southwest
will see some breaks over the Kuskokwim Delta and western portions
of the Kuskokwim Valley at times today.
All attention then turns to the next system that is expected to
move into Southwest Alaska later this evening/tonight. A North
Pacific low now south of the Eastern Aleutians will spread a front
over the Alaska Peninsula later this evening with increasing rain
chances. Initially easterly winds along the front will transition
to southeasterly behind the front, with gusty southerly gap winds
to develop across the Alaska Peninsula behind the front. Models
have come into better agreement with the placement timing of the
North Pacific system. Greater confidence exists with the center of
the low lifting northeastward across the Aleutians near Unimak
Pass and west of Cold Bay roughly around 4AM Wednesday morning. As
the low continues into the Kuskokwim Bay on Wednesday another
round of widespread rainfall is anticipated across Southwest
Alaska. This next round of precipitation will be lighter and
shorter in duration, with the bulk of rainfall only clipping the
Bristol Bay area and instead moving across the Kuskokwim Delta
through Wednesday morning and afternoon.
Beyond Wednesday the next low pressure system, yet another North
Pacific low, will be approaching the Western Aleutians. Forecast
models take this low into the southern Bering by Friday with its
front sliding across the entire Aleutian Chain during the same
time period. Thus, an active pattern looks to continue for the
Bering and Southwest. Precipitation chances will again arrive to
Southwest Alaska on Friday and continue into the weekend.
-BL
&&
.LONG TERM FORECAST (Days 4 through 7 - Friday through Monday)...
True to early September, the weather will remain active for much
of Southwest and Southcentral Alaska through the weekend into
early next week. For the period beginning on Thursday night, the
pattern will be characterized by a ridge across the eastern Bering
Sea into the North Pacific and western Gulf of Alaska, with a
strong low across the Aleutians, likely centered somewhere near
the Rat Islands, and moving northeastward in the direction of the
Pribilof Islands. Meanwhile, Southcentral Alaska will be under the
influence of a departing trough. Rain will likely be diminishing
across Southcentral AK Thursday night into early Friday, with the
greatest uncertainty in how quickly it clears up depending on the
low timing.
Attention turns towards the gale-force low in the Bering Sea
Friday and Saturday as it treks northeast towards the Pribilofs
and then Southwest Alaska. The Aleutian Chain gets the worst of
the weather from this system as the attendant fronts draw
northward an atmospheric river from the North Pacific which will
bring heavy rain and strong gale-force winds to the chain as it
sweeps across.
Model agreement is surprisingly good with this system, suggesting
a `landfall` of the low near Nunivak Island Saturday evening,
weakening to somewhere in the vicinity of 995mb as it does so.
There`s also decent agreement that, while the first half of the
weekend might be dry for Anchorage and the rest of Southcentral,
precipitation then overspreads SC AK late Saturday and Sunday as
moisture is drawn northward from the North Pacific. At this time,
this looks like a widespread wetting rainfall, but the good news
is that the numbers/probabilities aren`t quite lighting up as an
anomalously heavy rain as we experienced at the end of last week.
What reasonable model agreement we had before is lost by the
start of next week. There are some signals of another strong low
marching across the Bering, while some models signal at a lower-
amplitude wavetrain. Either way, it`s September in Alaska- be
prepared for rains to glisten the yellowing foliage.
-Brown
&&
.AVIATION...
PANC...Off and on showers will persist this morning, along with
MVFR ceilings at times. Ceilings will rise and become
predominantly VFR by late morning. However, 5,000 foot ceilings
could linger with light southerly flow in the lower levels and
continued moist southwesterly flow in the middle to upper levels.
Southeasterly Turnagain Arm winds will also shut off early this
afternoon with winds becoming light and variable. A front lifts
northward across the western Gulf for Wednesday morning bringing
the chance for another round of showers across the terminal.
Ceilings look to remain VFR Wednesday morning, but around 5,000
feet with a lower deck developing at times. Flow should be
predominantly down-inlet Wednesday morning with light north winds
across the terminal and winds in Turnagain Arm bending down-inlet
as well.
&&
$$
428
FXAK69 PAFG 021326
AFDAFG
Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
526 AM AKDT Tue Sep 2 2025
SYNOPSIS...
Wet weather will continue for much of Northern Alaska as fast
moving systems will bring round after round of rain. Increasing
rain chances today in the Eastern Interior, as a cold front moves
over the area. The Western Interior will see a quick reprieve this
evening as dry air is following behind a cold front, however this
will not last as another round of rain is expected Wednesday
evening. The North Slope will see scattered rain chances through
the week.
KEY WEATHER MESSAGES...
Central and Eastern Interior...
- Light showers are continuing across the Central and Eastern
Interior this morning. These will scatter out by Noon today.
- More rain showers spread over the area Wednesday PM with
increasing chances by Thursday afternoon with a soaking rain
possible in the Eastern Interior Thursday night into Friday.
- Temps stay in the low to mid 60s for most, with low to mid 70s
in the Upper Tanana Valley.
West Coast and Western Interior...
- Rain is continuing in the Western Interior with showers along
the coast through this afternoon.
- 0.05 to 0.15 inches additional rain in the Interior Valleys.
- 0.10 to 0.25 inches additional along the Coast.
- Up to 0.40 inch in the higher terrain of the Interior.
- Another round of rain moves into Southern Interior Wednesday
morning, to the northern Interior by Wednesday evening.
- Additional 0.50 to 1.00" possible.
North Slope and Brooks Range...
- Periods of rain continue in the Brooks Range through Thursday.
- 1 to 2 inches of rain through Thursday.
- Chukchi Sea Coast gets scattered to numerous showers through
tomorrow with isolated showers possible elsewhere this week.
- 0.15 to 0.50 inches of rain from Utqiagvik to Point Hope
through Thursday.
- A trace to 0.10 inches elsewhere along the Slope and Coast.
- Atigun Pass will see up to 0.75 inches of rain through Friday
with the heaviest rain on Thursday. Overnight Tuesday and
Wednesday could see snow mix in with the rain creating a
rain/snow mix. Snow totals would be around an inch through
Wednesday.
FORECAST ANALYSIS AND DISCUSSION...
An occluded low is rapidly weakening and quickly moving Northeast
from the Y-K Delta to Canada. This low will bring a sweeping cold
front across the Interior today. An 850 mb jet of 30 to 40 mph
will accompany this front. In the higher terrain there will be
some gusty southwest winds, while the valleys could have an
occasional gust of 20 mph. The winds will quickly calm down once
the cold front moves past, as there is not really any surface
pressure gradient to accompany this system.
Looking towards Wednesday with our next system. By the time it
passes the Aleutian Islands early Wednesday morning, cold and dry
air is wrapping into the low level circulation. This will inhibit
the growth of the system through the whole column. With the
moisture cutoff from the main moisture feed in the North Pacific,
rainfall is looking to be less than the past few storms. The south
facing slopes of higher terrain will still see higher rain
amounts, due to upsloping. The Western Interior Valleys will see
more showery precipitation due to the weak frontal strength. This
system will move across the Interior Thursday. An arctic airmass
will reinforce this sytem as it is over the Eastern Interior.
Bringing cooler temperatures, and increasing rain chances.
Fire Weather...
Most of the concern remains in the Upper Tanana Valley.
Temperatures have been above normal for some time now in the Upper
Tanana Valley, and will continue until Friday when an arctic
airmass will come through the area. Cloud cover will help to keep
minimum RH values above 40 percent across the Eastern Interior.
Ridgetop winds will be gusty today as a weak cold front moves
through the Eastern Interior. There could be some gusts up to 25
mph on the ridgetops.
HYDROLOGY...
A variety of flood products remain across the Interior and Brooks
Range. Additional rainfall is likely through today with up to
0.75 inches possible in the Brooks Range, and generally 0.1 to
0.25 inches across Western Alaska. There will be very slow
improvement to the current river statuses this week and we expect
them to remain high. Additional waves of rain look likely during
the middle and end of the week as there is no end in site. For the
most updated forecasts and warnings, visit:
weather.gov/afg and weather.gov/aprfc
EXTENDED FORECAST DAYS 4-7...
Another low pressure system will move into the Bering Sea by
Friday morning. This low will be accompanied with moisture from
the Central Pacific. As we move into Friday evening another round
of rain will move through the Western Interior. By Sunday night
this rain will make it`s way into the Eastern Interior. This rain
could be heavy at times, but will be showery in nature. The warm
front looks to be fairly weak, but the Eastern Interior could see
a brief warm up Sunday before the rain arrives.
Coastal Hazard Potential Days 3 and 4...None
&&
.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Flood Watch for AKZ813-814-819-828-831.
PK...Small Craft Advisory for PKZ801-802-853-859.
Small Craft Advisory for PKZ803-852.
Small Craft Advisory for PKZ804-861.
Small Craft Advisory for PKZ805.
Small Craft Advisory for PKZ810-811-856.
Small Craft Advisory for PKZ812.
Small Craft Advisory for PKZ813-814.
Small Craft Advisory for PKZ850.
Small Craft Advisory for PKZ860.
&&
$$
Dennis
463
FXAK67 PAJK 021733
AFDAJK
Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
933 AM AKDT Tue Sep 2 2025
.UPDATE...18Z Aviation Discussion and Mid-Morning Update...
No major changes to the forecast this morning. The main headline
continues to be the unseasonably warm and dry conditions across
the Panhandle. The marine layer will continue to impact the
northern gulf and areas into Cross Sound and Icy Strait through
the day. This marine layer will weaken any sea breeze development
along those areas, and will keep temperatures slightly cooler
with increased cloud cover.
&&
.SHORT TERM.../through Tuesday night/...
Similar to yesterday, the above normal temps and clear skies
continue for SE AK.
Key Messages:
- Clear skies with near 0% chance for precip.
- Above normal afternoon highs in the 70s to around 80 likely for
most of the area.
- With the exception of sea breezes, wind speeds will remain
light.
- Some concern for spotty areas of marine layer development.
Details: High pressure continues over the gulf and it is the main
character in our weather story. This high pressure is keeping the
rain at bay and keeping the dry/sunny weather in place.
We are also seeing some very warm air aloft, upwards of 10+
degrees C above normal for this time of year at the 850mb level.
So, once that warm air is able to mix down to the surface, highs
in the 70s to around 80 are likely around the panhandle. That
being said, for those along the coast, slightly cooler temps in
the 60s to around 70 are most likely.
A couple variables that can break this temperature forecast are
sea breezes and marine layers.
For those near the water, if a sea breeze is able to develop,
that will keep temps much lower than the forecasted 70s. So the
farther away from the water you are, the more likely of seeing 70s
Tuesday afternoon.
The marine layer, while a lower chance of happening, would keep
temps cooler. For now, mainly looking at Yakutat for any marine
layer impacts, that would include fog, but if the extra moisture
is able to slide east into Icy Strait, it would keep afternoon
temps cooler for those in the northern panhandle. Otherwise,
anticipate the marine layer to redevelop and impact the outer
coastal waters, southern panhandle, and Icy Strait Corridor
Tuesday night in to Wednesday morning.
.LONG TERM...Continuing to see the high pressure linger over
the Gulf, allowing for warmer weather and preventing precipitation
and cloud cover from reaching the panhandle. This will keep the
clear skies and warmer than average temperatures across the
panhandle through Thursday, with the warmest temperatures in the mid
to high 70s up to around 80 degrees extending into Wednesday now.
NBM guidance for the southern panhandle and parts of Juneau and
Haines show probabilities of around a 40-60% chance of exceeding 80
degrees on Wednesday afternoon. This is alongside 850 mb
temperatures still remaining 13-15 degrees C over the northern
panhandle and 17-19 degrees C over the southern panhandle into 00Z
Thursday. Inland areas will be the warmest across these areas
Wednesday, before generally beginning to decrease into the end of
the week. Thursday looks to still be rather warm, still having some
13-15 degree C temperatures at 850 mb and clearer skies in the
northern panhandle that morning and afternoon, but not expected to
be as warm as Wednesday.
Precipitation will begin to slowly push into the northeast Gulf
coast around Yakutat Thursday night into Friday, bringing some light
rain chances across parts of the panhandle throughout the day
Friday. These chances remain low still with between 15 and 30% PoPs
Friday into the weekend, as there is potential for the surface high
to still linger and prevent as much moisture actually pushing into
the panhandle. The largest barrier to precipitation moving in will
remain dependent on when the surface high pressure actually
breaks down and begins to allow for systems to move in from the
west.
&&
.AVIATION...Mainly VFR conditions prevail across the panhandle with
the exception of Yakutat where a marine layer has developed and
will continue to bring ceilings below 2000 ft through the day.
This marine layer is starting to develop across Cross Sound and
Icy Strait. Across other areas of the panhandle, mostly clear
skies will continue throughout the day. Winds will once again
increase during the late morning to afternoon hours as sea breezes
develop. Areas near Ketchikan are already seeing increased winds
up to 10 kts. Similar to previous days, these winds will continue
to increase with the highest winds around 15 kts.
For tonight into tomorrow morning, the marine layer will persist.
The marine layer is expected to move slightly southward and start to
impact and lower the ceilings along the coast off of Sitka, Prince
of Wales Island, and into the southern panhandle. With the marine
layer, visibilities and ceiling will lower to MVFR with times of
IFR. This will impact daily warming and sea breezes along areas
that have a marine layer develop.
&&
.MARINE...
Outside: Little change from yesterday. High pressure continues to
control our skies here in SE AK. Swell remains out of the south
at 2ft 14-18 seconds, with wind waves of 6 to 10 ft less than 10
seconds along the Prince of Wales (PoW) Coast and Dixon Entrance.
These wind waves are being driven by fresh to strong breezes (17
to 27 knots) out of the NW, highest winds off the coast of PoW and
Cape Fairweather. Wind speeds look to decrease for the second
half of the week as the high pressure weakens.
Inside: Sea breezes continue to be the primary concern for the
inner channels over the next 48 hours. Reported winds speeds have
been getting up to around 10 to 20 kts in the usual trouble
spots, Near Point Couverden, the tighter spots in Stephen`s
Passage, and in Southern Chatham Strait. Winds should calm down
during the overnight and stay lighter into Tuesday morning before
picking back up again for Tuesday afternoon. Wind speeds look to
decrease for the second half of the week as the high pressure
weakens.
&&
.FIRE WEATHER...Hot and dry conditions continue with poor RH
recovery, relative to rainforest standards, for areas above the
marine influence (above 1500ft). FFMC continues to drive the fire
danger indices, residing in the upper 80s to low 90s in select
areas of Prince of Wales, Ketchikan, and Skagway. The message
remains consistent, we do not expect large 10+ acre fire growth in
old growth timber; however, fire danger for fine flashy fuels
continues to persist.
&&
.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Heat Advisory until 7 PM AKDT Wednesday for AKZ319-325-328-330-
332.
MARINE...Small Craft Advisory for PKZ641>644-661>664.
&&
$$
SHORT TERM...GFS/GJS
LONG TERM...Contino
AVIATION...EAB
MARINE...GFS/AP
Fire...GFS/AP
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