501
FXUS63 KBIS 060412
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
1112 PM CDT Tue Aug 5 2025

.KEY MESSAGES...

- Isolated to scattered severe thunderstorms are possible
  through this evening.

- Severe weather is possible again on Thursday, possibly
  lingering into eastern portions of the area into Friday.

- Quieter and seasonably cool weather expected for the upcoming
  weekend.

&&

.UPDATE...
Issued at 1112 PM CDT Tue Aug 5 2025

A few storms continue to be found close to an upper level low in
the northwest and north central. There is some modest
instability in this area, although shear is lacking. Have
adjusted PoPs to account for this activity over the next few
hours. Low clouds have formed as clouds are clearing. There
could be some patchy fog tonight given lingering high humidity
and light winds. Added patchy fog mention in the forecast for
central and eastern portions.

UPDATE
Issued at 858 PM CDT Tue Aug 5 2025

Severe weather threat has moved out of the CWA, thus have
cancelled the remaining Tornado Watch. A few lingering showers
and thunderstorms may be found through the evening in the east
and the northwest. Of concern are high rainfall amounts in
southeastern portions of the state. Here 2 to 6 inches of rain
have fallen this afternoon and evening, with isolated reports of
7 inches. Have extended the Flash Flood Warning to cover the
areas with higher rainfall totals from this evening. Have also
issued a Flood Advisory for other areas with high rainfall
amounts and some reports of minor flooding so far. This Flood
Advisory will go through the night.

UPDATE
Issued at 805 PM CDT Tue Aug 5 2025

Upper level wave and associated low level jet has shifted
eastward. Thus will cancel a bulk of the Tornado Watch, although
areas with current thunderstorm activity will still remain in
the watch. Heavy rainfall may still bring a flooding threat
through the evening.

UPDATE
Issued at 710 PM CDT Tue Aug 5 2025

Tornado Watch Continues until 10 PM CDT / 9 PM MDT in much of
south central North Dakota. High CAPE and high shear will
continue through the evening, with much of the shear coming in
the lower levels due to a low level jet. With high dewpoints and
low LCLs, a tornado is possible possible with supercells or
rotation in QLCS lines of storms. Area with the highest tornado
threat generally remains in the James River Valley through the
evening. With high shear and CAPE hail up to two inches in
diameter will be possible. Wind gusts could be up to 70 mph with
high 0 to 3 km shear, although DCAPE is somewhat lacking. All
thunderstorms could produce heavy rainfall as Pwats are over 1.5
inches in most areas, and storm motion is somewhat slow. Anyone
within the Tornado Watch should stay weather aware this
evening.

&&

.DISCUSSION...
Issued at 221 PM CDT Tue Aug 5 2025

Showers continue over parts of northwestern and north central North
Dakota, while scattered sub-severe (though strong at times)
thunderstorms continue to develop in south central ND. The big
question remains as to what exactly will happen this afternoon.
The RAP suggests plenty of instability at around 2000 to 3000
J/kg of MUCAPE near the ND/SD border with little CIN by mid-
afternoon. However, with convection that passed through this
morning, and continues at this time, stratus still covers much
of the forecast area. So there definitely remains some question
as to how much the environment can recover this afternoon, and
just how widespread the severe weather threat will be.

Based on current satellite imagery and forecast models, there
seem to be two areas most likely to see more organized
thunderstorm development today. The first is in northwestern
ND, where skies have mostly cleared and isolated strong to
severe thunderstorms are possible. The second, and probably the
most favorable area for severe weather, is the south central,
especially along and south of I94. The south central is where
both skies have begun to clear and elevated mixed layer
dewpoints at around 65 degrees are present. That said,
definitely can`t rule out development in the southwest either,
or a few storms north of I94 becoming severe.

Should additional organized thunderstorms develop this
afternoon in the south central, adequate shear is progged with
around 30 to 40 kts of 0 to 6 km bulk shear. Overall storm mode
is favored to be more clustered, though a few discrete cells
may develop during the afternoon. Combined with more than
adequate shear and the potential for a few discrete cells, along
with aforementioned 2000 to 3000 J/kg of MUCAPE, golf ball size
hail, winds up to 70 mph, and a tornado or two remain the
biggest threats.

Once any thunderstorms clear out late this afternoon or evening,
expect mostly dry conditions for the remainder of the night
through Wednesday. There are low chances for shower and
thunderstorm development in southwestern ND Wednesday evening,
but severe weather seems unlikely at this time. Beyond
Wednesday, severe thunderstorm potential returns both Thursday
and Friday. On Thursday, elevated instability and increasing
shear are progged in some model output. This could result in
scattered severe thunderstorm development anywhere in the CWA.
Models then agree that upper low pressure moves from west to
east across south central Canada to end the week. A stronger
trough off this low could produce additional severe weather on
Friday, especially in southeastern parts of the forecast area.

A gradual warming trend is expected through Thursday with highs
forecast to reach the low 80s to low 90s. A cooldown is then
favored to finish out the week with highs in the 70s possibly
returning for much of the state. Lows will also return to the
50s for much of the area.

&&

.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 710 PM CDT Tue Aug 5 2025

Showers and thunderstorms will be possible through this evening
across eastern TAF sites, with some isolated coverage elsewhere.
MVFR to perhaps brief IFR conditions are possible with any
thunderstorms. Strong winds and hail are also possible with
strong to severe thunderstorms. Showers and thunderstorms then
diminish late this evening into the early overnight hours. Some
MVFR cloud cover could linger across central and eastern sites
tonight, with VFR cloud cover moving from west to east later
tonight through Wednesday morning. The remainder of Wednesday
looks to see VFR conditions with some westerly winds, perhaps
breezy at times.

&&

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

&&

$$

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