796
FXAK68 PAFC 010037
AFDAFC
Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
437 PM AKDT Thu Jul 31 2025
.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3: This
afternoon through Sunday afternoon)...
The overall forecast remains largely on track, with some minor
fine-tuning of details. The biggest change since the overnight
forecast package has been to hone in on areas of potential
thunderstorms. With the more stable marine air in place along Cook
Inlet and weak flow aloft, have gone with a forecast that keeps
isolated thunderstorms limited primarily to the higher elevations
today. A storm or two could still drift over populated areas later
this evening as northeasterly flow aloft strengthens, but it`s
unlikely that the major Southcentral population centers will see
any lightning. Thunderstorm potential continues into tomorrow
afternoon and evening, but will mostly be limited to the higher
elevations along the Mat-Su Valleys. Otherwise, the Southcentral
Mainland as a whole will lean a little wetter as upper level
shortwave troughs rotate around a low in the far southern Gulf, bringing
bands of steady light rain to Southcentral. Most areas will see
some rain between this afternoon and Saturday afternoon, after
which rain will taper off and lead to drier conditions for Sunday.
-KC
&&
.SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS (Days
1 through 3/Tonight through Saturday night)...
An omega block pattern has set up across the Bering Sea and
Southwest Alaska as the high amplitude ridge centered over the
eastern Bering and western Alaska is flanked by a vertically
stacked low in the Gulf and a deepening low in the North Pacific.
Areas of fog continue to persist across the region under the
ridge, though it will become less widespread in the coming days.
Mostly clear skies and warming temperatures are expected through
Saturday for Southwest Alaska, with a slight chance of afternoon
and evening thunderstorms along the western slopes of the Alaska
Range.
The main weather driver and focus over the next few days will be
the aforementioned North Pacific low as it continues to track
northwards across the western and central Aleutians tonight. This
system will send a series of fronts across the Aleutian Chain and
Bering Sea as it occludes and stalls in the central Bering Sea
throughout the weekend. The system is expected to peak in
intensity tonight, bringing a swath of gale-force winds across the
central Aleutians this evening into early Friday morning.
Widespread rainfall along the Aleutian Chain will decrease
tomorrow afternoon as precipitation begins to become more focused
along the frontal boundary as it progresses east across the
Alaska Peninsula and stalls near the Southwest Alaska coast by
Sunday morning. Moderate to heavy rain is likely at times for the
eastern Aleutians and southern AKPen as the system taps into a
robust supply of Pacific moisture, with many areas along the
southern AKPen receiving up to 1-2 inches of rain. Weather across
the Bering Sea and Aleutian Chain will remain generally unsettled
through the end of the weekend as the low continues to remain
nearly stationary into early next week.
&&
.LONG TERM FORECAST (Days 4 through 7 Monday through Thursday)...
The general synoptic pattern shows a low near the southeastern
Panhandle and a broad low over the Bering Sea transiting
southeastward across the Aleutians and Alaska Peninsula. Situated
between the lows and across much of the mainland is high pressure.
The front from the Bering Sea low will bring ample moisture
across the Alaska Peninsula starting this weekend. There are some
indications that multiple waves could keep precipitation across
the Alaska Peninsula into early next week. While there is moderate
to somewhat high confidence in the synoptic setup for the long
term, confidence in the precipitation details remains moderate to
low with the duration and amount of precipitation for next week.
Especially for the Alaska Peninsula, southwestern Alaska coast,
and Kodiak Island. Model consensus breaks down further into
midweek. Some models hint at low pressure interactions between a
new North Pacific low and the main Bering low as it transits
across the Alaska Peninsula. This could bring about gale force
winds along the frontal boundary.
Toward Southcentral, the forecast challenge will be with the
ridge across the mainland. The southeastern Panhandle low will
break down, but the potential for showers and thunderstorms
associated with the easterly waves will depend upon the timing of
the breakdown in the synoptic pattern into the Copper River Basin,
across Southcentral, and its extent into the Kuskokwim Valley.
There are also indications of a shortwave trough sinking into
Southcentral late Tuesday and the eastward push of the front from
the west.
Rux
&&
.AVIATION...
PANC...There are a few more tricky aspects to the PANC airport
forecast through tomorrow. We will start off with the light flow
and moist, stable airmass left over after the rain yesterday.
This airmass will keep the threat of low stratus re-developmentr
around through Friday noon, though more fog development is
unlikely. There is also a slight chance for a thunderstorm to
develop over the Chugach Mountains late this afternoon into the
evening hours and drift into the vicinity of the airport.
Steering flow is weak and the stable marine airmass at low levels
will probably keep storms from reaching the airport, but they
could wander off the Chugach to the east of the airport. Winds are
generally expected to be on the light side overall, though they
are likely to turn southerly around 10 kt for the evening hours
this evening.
&&
$$
897
FXAK69 PAFG 312037
AFDAFG
Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
1237 PM AKDT Thu Jul 31 2025
.SYNOPSIS...
Warmer and drier weather is inbound as a high develops over
Northern Alaska. Summer-like temperatures will be around through
the weekend with chances for showers and storms, mostly in the SE
Interior and Alaska Range, though a sporadic shower is possible
in the White Mountains and higher terrain of the Interior. North
Slope will be warming up and gradually losing the fog/stratus as
offshore flow dominates.
&&
.KEY WEATHER MESSAGES...
Central and Eastern Interior...
- Dry and warm weather with plenty of sunshine through this
weekend.
- A few showers remain in the Eastern Interior today with some
embedded thunderstorms likely, especially in the SE Interior.
- Similar story tomorrow, but storm chance extends to AK Range.
- Scattered to numerous showers on Saturday in the Eastern
Interior and Eastern AK Range. 0.25 - 0.50" of rain possible
(Fairbanks stays mostly dry).
West Coast and Western Interior...
- Dense morning coastal and valley fog to 1/4 mile at times Friday
morning.
- Dry and warmer weather through the weekend with highs 5 to 10
degrees above normal.
- Isolated thunderstorm chances in the Western AK Range and near
McGrath tomorrow afternoon, Lower Yukon/Kusko Valley on
Saturday, Middle Yukon Valley on Sunday.
- Increasing southeast winds with peak gusts to 35 mph and
isolated showers in the YK Delta Friday into Saturday
North Slope and Brooks Range..
- Clearing skies along the coast as offshore flow dominates. There
may be some stratus or fog returning each night, but the
afternoons should be nicer and warmer overall.
- Isolated showers in the Brooks Range, but overall it will be a
warmer and drier weekend.
&&
.FORECAST ANALYSIS AND DISCUSSION...
High pressure moving in. There will be continued chances for rain,
especially in the SE Interior and Alaska Range each day. Though
the most widespread rain looks to be on Saturday as a front from
the low in the Gulf moves north. This front likely stalls in over
the Fortymile and Eastern AK Range on Saturday, so rain is not
expected in Fairbanks. Otherwise, typical summertime showers are
expected over the higher terrain of the Interior through this
weekend so while it won`t be completely dry, it`ll be drier than
it has been. A low in the Bering will bring gusty southeast winds
and showers to the YK Delta tomorrow through Saturday, but that`s
as impactful as it gets for that area. The North Slope will be
warmer and drier as well, getting away from the stratus and fog
for a little bit.
&&
.FIRE WEATHER...
Warmer and drier weather with much of Northern Alaska reaching
the 70s by Saturday. Min RHs will get as low as 30 to 35% in
Interior valleys this weekend. Showers and storms aren`t ruled out
either. Most of the rain will be in the SE Interior and Alaska
Range, especially tomorrow and Saturday. A front on Saturday will
stall over the Fortymile and Eastern Alaska range with the
potential for upwards of 0.50" in the terrain, and 0.10 to 0.25"
in the upper Tanana Valley. Expect typical summertime showers for
the rest of the terrain of Interior Alaska, but thunderstorm
activity will be limited to the SE Interior and Alaska Range today
and tomorrow. Then in the Middle/Lower Yukon Valley this weekend.
Winds will be largely light, but from the Northeast through
Saturday as well.
&&
.HYDROLOGY...
No concerns as rivers are cresting today then gradually falling
through the weekend.
&&
.EXTENDED FORECAST DAYS 4-7...
Looking towards next week the models are in agreement with the
main features that will move through the area. However, the
biggest uncertainty will be what the arctic trough does as it
moves across the North Slope Monday through Thursday. We could
potentially see multiple fronts associated with this trough as it
moves across the North Slope bringing temperatures below normal as
well as chances for showers. In the Interior a shortwave feature
over Southcentral Alaska will create a triple point low with the
main low pressure in the Bering Sea. This will keep advecting
moisture into the Interior, allowing for a continued showery
pattern into the middle of next week. This would also cool the
Interior down to near normal temperatures by Tuesday.
Coastal Hazard Potential Days 3 and 4...None
&&
.AFG WATCHES/WARNINGS/ADVISORIES...
AK...None.
PK...Small Craft Advisory for PKZ811-857.
Small Craft Advisory for PKZ816.
Small Craft Advisory for PKZ851.
Small Craft Advisory for PKZ858.
Small Craft Advisory for PKZ859.
&&
$$
Bianco
Dennis - Extended
707
FXAK67 PAJK 010544
AFDAJK
Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
944 PM AKDT Thu Jul 31 2025
.UPDATE...Aviation section updated for 6z tafs.
&&
SHORT TERM.../Through Friday Night/...Overall, Southeast Alaska
will continue to experience fairly benign weather through the
period. A weak low will continue to meander over the Gulf with
weak atmospheric disturbances rotating around it, moving northward
toward the Panhandle. These will bring with them increased
cloudiness & only light rain showers. We are currently wrapping up
our time period of lull between disturbances until later this
afternoon / evening when another disturbance begins to move
through the region. As far as winds are concerned, they should
remain on the lighter side through the period with some areas
possibly getting some enhanced sea breeze winds this afternoon
that received enough sunshine/breaks in the clouds & warmed-up
enough. Normal to above normal temperatures will remain in store
for the region through the period.
LONG TERM...
Key messages:
- A vertically stacked low remains over the gulf continuing to bring
light precipitation to the panhandle.
- The potential for moderate to heavy rain continues for Sunday into
Monday.
Details: The vertically stacked low, that is currently over the Gulf
of Alaska, will remain in the gulf through the weekend. This low
will continue to send waves of light precipitation toward SE AK.
Specifically, a band of precipitation will move across the panhandle
Friday into Saturday. This precipitation will mainly be focused on
the northern panhandle. Even with more rain expected, 24 hour rain
totals remain below half an inch. In the area from Icy Strait to
Yakutat, there is around a 60% to 80% chance of seeing greater than
0.5 inches in 24 hours. The low in the gulf will begin to weaken on
Saturday allowing for breaks between the rain.
As the low in the NE gulf begins to dissipate, a low begins to move
across the gulf. This low develops in the western gulf and will then
make its way toward the southern panhandle Sunday into Monday.
Confidence has increased that this low will bring moderate to heavy
rain toward the southern panhandle. Currently, rain totals remain
between 0.75 and 0.25 inches in 24 hours for the southern panhandle.
With around or below 0.5 inches for the central and northern areas.
During these systems, winds remain fairly light with land winds
around 5 to 10 mph. Wind along marine waters will see times of
increased winds as the associated waves, from the low, move over the
area. The strongest expected winds are near 20 to 25 kts, so no
large impacts are expected at this time. Between systems, winds will
remain between 5 to 15 kts.
AVIATION...The next band of precipitation is starting to move into
the panhandle over Prince of Wales and Baranof Islands, though no
sites have reported rain as of yet and conditions are still VFR at
the moment. This band will push north over the panhandle
overnight, bringing light rain and MVFR to IFR ceilings starting
in the south after midnight and making it to northern airports by
early Friday morning. Early Friday morning, some inner coastal
areas and Yakutat may see a low cloud layer impacting
visibilities, similar to yesterday. This should rise through the
morning, though with the band of precipitation moving out of the
area that morning the cloud layer may not get low enough to impact
VIS. Wind speeds will increase slightly as the band passes over,
though most surface areas will remain 10 kts or less.
MARINE...Inside Waters: A relatively relaxed pressure gradient
over the Inner Channels will mainly keep winds at around 10 kt or
less over the next few days. The exception will be through this
afternoon & evening hours for northern Lynn Canal and Clarence
Strait as the gradient tightens up at little bit as the next
atmospheric disturbance pushes through. The same thing happens
again for Friday afternoon & Friday night after which winds will
drop back down to 10 kt or less, once again. Seas will remain
around 3 ft or less through the period.
Outside Waters: The relatively tighter SFC pressure gradient
around the weak meandering low in the Gulf will cause
southeasterly winds between around 10 & 20 kt into the weekend.
Peak seas of up to around 6 ft are expected with a south to
southeasterly swell through the period.
&&
.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...None.
&&
$$
SHORT TERM...JLC
LONG TERM....EAB
AVIATION...ZTK/EAL
MARINE...JLC
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