296
FXUS63 KBIS 211131
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
631 AM CDT Tue Jul 21 2026

.KEY MESSAGES...

- Cooler today with a few showers in the southwest.

- Warming temperatures and mainly dry conditions expected
  through Thursday.

- Very hot conditions expected to return Friday through the
  weekend, with high temperatures and heat index values
  potentially above 100 degrees.

&&

.UPDATE...
Issued at 630 AM CDT Tue Jul 21 2026

Limited updates needed this morning. Some northern sites are
reporting reduced visibility in haze and mist. This could be
patchy fog trying to form, with high clouds limiting it, some
patchy smoke moving in, or a combination of both. Have kept
patchy fog through the mid morning to account for the patchy fog
potential. Otherwise the forecast overall remains on track.

&&

.DISCUSSION...
Issued at 335 AM CDT Tue Jul 21 2026

Light winds and high RH values could bring some patchy fog this
morning, although mid to high level clouds look to limit this
threat. Some lower clouds may also be found in the southeast
this morning. Stalled surface front with northwest flow aloft
will bring a brief cool down today. High temperatures will
generally be in the mid 70s to lower 80s, which will be slightly
below normal for most locations. Wind will be less windy today
with a surface high to our north. The stalled front could bring
a few high based showers to the southwest today, with a low
threat for thunderstorms. Some haze or patchy wildfire smoke is
also possible today given the northwest flow aloft. Surface
high moves across the region tonight bringing mainly clear skies
and cooler lows in the 50s. Light winds combined with clear
skies and cooler temperatures could bring some patchy fog,
although confidence was not high enough to include at this time.
Wednesday through Thursday, surface high moves eastward while an
upper level ridge begins to build back into the area. Southerly
flow at the surface will begin to warm temperatures back to
normal to perhaps slightly above normal readings. Dewpoints
should remain low, limiting the heat risk. Depending on
placement of the upper level ridge, northwest flow aloft could
bring some weak waves in the flow and perhaps some low
precipitation chances. Instability looks limited on Wednesday,
although becomes slightly more increased on Thursday, with
perhaps and isolated thunderstorm possible. Right now the NBM
has a mainly dry forecast, with better chances for
precipitation in South Dakota.

Friday through the weekend, large upper level ridge looks to
shift just enough to the east to return very hot temperatures
and perhaps some dangerous heat risk. Forecast highs in the 90s
to low 100s, and low temperatures in the 60s remain in the
forecast. There could still remain some heating bias from the
last warming trend in the NBM, although the NBM spreads at least
indicate another strong warming trend coming this weekend. Much
lower dewpoints will be found for this upcoming weekend`s heat.
Even so Heat Risk and Wet Bulb Global Temperature values are
showing high to extreme heat risk. Heat Index Values may also be
near to above 100 degrees especially on Saturday. Will continue
to monitor for potential heat products. Depending how strong
the ridge builds there could be near daily chances for showers
and thunderstorms Friday through the weekend with any ridge
rider type waves. These same disturbances could bring some
increased winds at times this weekend. This combined with low
afternoon humidity values in the teens and 20s may also bring an
increased fire weather threat this weekend. Overall those with
outdoor plans will want to start planning for a hot weekend with
some slight shower and thunderstorm chances.

&&

.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 630 AM CDT Tue Jul 21 2026

Some low clouds and patchy fog could bring MVFR to brief IFR
conditions this morning, mainly in the west and north.
Confidence was only high enough to include a TEMPO group for
MVFR ceilings at KDIK this morning. Confidence was too low to
include fog mention at this time. Look for VFR conditions for
the remainder of today through tonight. Northerly winds will
linger for today becoming east northeast this evening, then
light and variable for most sites. A few light rain showers are
possible in the southwest today. Some wildfire smoke may also
return to the region today, although confidence in any
visibility or ceiling impacts is low.

&&

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

&&

$$

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