296
FXUS63 KBIS 111440
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
940 AM CDT Tue Aug 11 2026

.KEY MESSAGES...

- Low to medium chances (20 to 50 percent) for thunderstorms
  late this afternoon through tonight. Isolated to scattered
  severe storms are possible, mainly in the south.

- Showers and thunderstorms could return again Wednesday.
  Isolated severe storms are possible in the south.

- Near average temperatures today, with a cooling trend then
  expected through Friday, followed by a warming trend through
  the weekend and into early next week.

&&

.UPDATE...
Issued at 940 AM CDT Tue Aug 11 2026

Isolated to scattered thunderstorms have formed between Highway
83 and Jamestown. The current Severe Thunderstorm warning will
be allowed to expire at 945 since the storm is no longer
intense. We are still in a level 2 risk today. If you believe
the CAMs no storms will happen before sunset, although the
current storms are on none of the CAMs so we will continue to
monitor that.

UPDATE
Issued at 612 AM CDT Tue Aug 11 2026

Isolated showers may skirt the far southwest early this morning.
Also an isolated shower recently developed over central Kidder
county. Adjusted pops to account for these areas. Also adjusted
sky cover with quite a bit of low VFR and pockets of MVFR
ceilings developing over the southern half of the state. Updated
text products will be transmitted shortly.

&&

.DISCUSSION...
Issued at 410 AM CDT Tue Aug 11 2026

A near zonal to slightly northwest upper level flow remains over
the area today and Wednesday, followed by a transition to a
broad southwest upper level flow through the end of the work
week.

Currently, late evening into early overnight convection has
ended over the area. A few showers were noted over southeast
Montana, otherwise skies were clear to partly cloudy. Low VFR to
MVFR ceilings have been developing over the past couple of hours
across central and into northeast ND. RAP forecast 925-850mb RH
indicates higher RH remaining along and south of the I-94
corridor through the morning and possibly into early afternoon.
As of yet there is little indication of any fog, but the
potential will remain through mid-morning.

This afternoon will bring another chance of thunderstorms to
western and central ND. In general, most guidance develops
convection in the late afternoon (after 21 UTC) over southwest
ND and tracks it southeast through the evening. There are some
CAMS that extend convection farther north into northwest and
north central ND, and others indicate late afternoon into
evening convection, followed by another round of overnight
convection, possibly lingering into Wednesday morning.

Strong (40-60kts) bulk shear will be over the forecast area
through the period. The greatest instability will be in the
southwest this afternoon into early this evening. The RAP does
indicate some elevated instability remaining over western ND
late tonight with a weak inverted trough near the Montana
border. Thus the probability of a couple rounds of convection
can not be ruled out. However, there isn`t much of a llj
overnight tonight which would help to maintain any late night
convection. The higher probability for strong to severe storms
looks to be late afternoon into this evening in the southwest
and south central. With the strong shear and supercell wind
profiles, we will keep the previous hazards of golf ball sized
hail and 70 mph winds. As there was earlier this evening, there
will be the potential for splitting cells again today.

A similar setup on Wednesday will take place with the greatest
instability by afternoon in southwest/south central portion of
the state. Strong shear remains over the area so any storms that
would be able to develop sustain themselves, would have the
potential to become severe. SPC currently has a marginal risk
for severe storms along and south of the I-94 corridor.
Currently, the instability does not look to be as strong
Wednesday so for the time being, will keep main hazards of
quarter size hail and 60 mph winds.

Later in the workweek, we transition to more of a broad
southwest upper flow with a series of waves moving through the
mean flow. With cooler temperatures in store Thursday and
Friday, instability will remain low, thus we expect more
showers and isolated thunderstorms with a low threat for severe
storms.

After Friday we begin a slow warm-up back to near normal
temperatures through the weekend and into early next week.
Westerlies remain over the area so we would expect a
continuation of the near daily chances for thunderstorms, rather
than a big warmup with dry conditions.

&&

.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 612 AM CDT Tue Aug 11 2026

Low VFR to MVFR ceilings continue to develop over the southern
half of the state. Most ceilings were VFR but MVFR ceilings at
KBIS to begin the 12Z TAF period. Potential for MVFR ceilings at
the southern TAF sites through this morning, but attim, only
mention of MVFR ceilings was at KBIS. Variable but mainly
easterly winds through the TAF period. Thunderstorms are
possible late this afternoon and tonight at all TAF sites with
gusty and erratic winds and MVFR ceilings/vsbys possible with
any thunderstorms that do develop.

&&

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

&&

$$

UPDATE...Smith
DISCUSSION...TWH
AVIATION...TWH