Williston, North Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

345
FXUS63 KBIS 221752
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
1252 PM CDT Sun Jun 22 2025

.KEY MESSAGES...

- Scattered to numerous showers and thunderstorms are expected
  today. A few storms may become severe this afternoon with
  golf ball size hail and 70 mph winds being the primary
  threats.

- A cooler weather pattern will be found to start this week,
  followed by a very gradual warmup, with near daily chances for
  showers and thunderstorms.

&&

.UPDATE...
Issued at 1252 PM CDT Sun Jun 22 2025

Severe Thunderstorm Watch in the northeast from this morning has
been expired as storms have moved out of the area. SPC has
shifted the risk of severe weather to the eastern third of the
state, although there could be at least an isolated risk through
this afternoon from about Highway 83 and eastward as a cold
front moves through. Abundant cloud cover may cap the high shear
and cape in this area. However if the cap can be broken, then
thunderstorms with large hail and damaging winds will be the
main threat. An isolated tornado would also be possible given
the high amounts of shear. Will continue to monitor and update
for any sever potential. Otherwise look for a breezy and cooler
day as the cold front moves through. Some areas of smoke may
also be found from wildfire smoke being pulled in behind the
front.

UPDATE
Issued at 954 AM CDT Sun Jun 22 2025

SPC has added Foster county into a Severe Thunderstorm Watch
until 2 PM CDT today. Thunderstorms are starting to develop
across central and eastern portions as a cold front makes its
way across North Dakota today. SPC has expanded the Slight Risk
for severe weather to include most of central and eastern North
Dakota. Surface and mix layers still appear to be capped,
although there is 1000 to 2000 J/KG MUCAPE the storms are
currently developing in. All areas have abundant shear, with
effective bulk shear over 50 knots in most areas. Thus a few
strong to severe storms are possible this morning, with hail up
to golf balls in any storms that has rotation, and winds up to
70 mph as 0 to 3 km shear and DCAPE values are increasing. As
the cap erodes and more surface based storms can develop this
afternoon, large hail and damaging winds will still be the main
threat. Any surface based storms could also bring an isolated
tornado threat given the high amounts of shear. The bigger
concern for this will be in eastern North Dakota. Lastly, pwat
values of over 1.5 inches today combined with abundant
thunderstorm activity could bring some localized flash flooding
potential, mainly in central and eastern portions.

Non-thunderstorm wise, some smoke has filtered in behind the
cold front this morning. Added mention of this in the forecast
as well for this update.

UPDATE
Issued at 638 AM CDT Sun Jun 22 2025

Showers and thunderstorms have developed across parts of western
through central ND, including the James River Valley. While
there has been lightning observed in most every cluster of
returns at some point, the most active one is the cluster
currently in central North Dakota and heading north. With the
more active thunderstorms, small hail and frequent lightning
will be possible at times. There remains a low severe threat
across the area this morning and afternoon, although CAMs are
leaning more towards a solution that is mainly showers along
with a few generic thunderstorms. The last NAMNest is by far the
most active of the CAMs, but based on storm initiation, seems
unlikely to come to fruition. All in all, the forecast remains
on track.

&&

.DISCUSSION...
Issued at 353 AM CDT Sun Jun 22 2025

Two surface low center circulations are present. One over
southern Saskatchewan and one over western Nebraska. Through the
morning hours and into the early afternoon, the northwesterly
low will merge with the one initially over western Nebraska
that will be simultaneously propagating to the northeast
through eastern South Dakota. These circulations will bring
scattered to numerous showers and thunderstorms and much cooler
temperatures to northern and western ND. Southeastern ND will
remain hot and muggy today.

At this time, showers and thunderstorms are beginning to
develop and expand into western and south central ND. A small
cluster that has recently entered from South Dakota near the
Missouri River produced a severe thunderstorm earlier on the
South Dakota side that has since weakened. 0 to 6 km bulk shear
is around 40 kts in that area with elevated instability in
excess of 2000 J/kg. These high instabilities should be
contracting from north to south through the morning hours,
though remain elevated in central ND near the ND/SD border and
the James River Valley. Bottom line is that the cluster is
gradually moving into a bit less favorable environment, but
still remains favorable enough to potentially produce a few
strong to severe storms this morning. Further west near the
ND/MT border, there is limited instability available, though
plenty of shear. This too could result in a few strong to severe
thunderstorms in the far southwest this morning. In either case,
the primary threats at this time are quarter size hail and 60
mph winds.

These showers and thunderstorms should continue expanding in
coverage this morning before ending from south to north in the
afternoon and evening. A few isolated showers could wrap into
the south central this evening and tonight, however. For
Monday, mostly dry conditions are expected, though a few
additional wrap-around showers are possible. Beyond that,
periodic shower and thunderstorm chances are expected through
the remainder of the week. CSU machine learning hints at a few
low end severe weather chances towards the end of the week. Will
monitor over the next few days to see if those chances increase
or decrease.

Overall temperatures for this week are expected to be much
cooler. Highs today will range from the 60s north and west to
the low 90s far southeast. Highs Monday should then range from
the low 60s to low 70s before temperatures return to the 70s
across the state on Tuesday. NBM highs are progged to return to
the 80s across most of the forecast area by the end of the week.
However, these are closer to the 25th percentile. As a result,
it`s very possible a day or two towards the end of the week will
see a return into the 90s for at least some of the area. Cooler
overnight temperatures are also expected with lows in the 40s
and 50s for the first half of the week, and the 50s and 60s to
end the week.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1252 PM CDT Sun Jun 22 2025

Cold front passage will bring areas of low VFR to MFR today,
with some brief IFR conditions. Abundant cloud cover will bring
low VFR to MFR ceilings to many sites today. Showers and
thunderstorms associated with the passing front could bring some
brief IFR ceilings as well today. Winds will become breezy and
westerly. Shower and thunderstorm activity diminishes through
tonight, although MVFR to perhaps IFR ceilings may linger to
most sites. Ceilings then look to improve to MVFR to VFR Monday
morning. Breezy westerly winds may also be found tonight into
Monday. Some smoke may also be found at times through the
forecast period, with limited visibility reductions expected.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

UPDATE...Anglin
DISCUSSION...Telken
AVIATION...Anglin