Mesoscale Discussion 2164
NWS Storm Prediction Center Norman OK
1041 PM CDT Fri Aug 28 2026

Areas affected...Parts of central/eastern SD into far southeast
ND/southwest MN

Concerning...Severe potential...Watch unlikely 

Valid 290341Z - 290615Z

Probability of Watch Issuance...20 percent

SUMMARY...Strong to locally severe storms may develop late tonight.

DISCUSSION...Capping has thus far inhibited robust storm development
across parts of central/eastern SD. However, increasing low-level
flow noted on regional VWPs is indicative of a strengthening
warm-advection regime that will likely lead to an increasing
coverage of elevated storms late tonight. MUCAPE of near/above 2000
J/kg and sufficient effective shear may result in development of an
elevated supercell or two, before at least modest storm clustering
and upscale growth occurs. 

Any initial discrete development or strong embedded cells within
later clustering could pose a threat of isolated large hail.
Increasing low-level stability with time and eastward extent may
hamper severe-wind potential, though some uptick in the wind threat
will be possible if a sufficiently robust cold pool can develop in
association with any nocturnal MCS. 

The need for watch issuance is uncertain due to potentially limited
coverage of the severe threat, but trends will continue to be
monitored for development of multiple elevated supercells and/or a
well-organized MCS later tonight.

..Dean/Guyer.. 08/29/2026

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...MPX...FGF...FSD...ABR...BIS...

LAT...LON   43329945 44109959 45930004 46289779 46009661 45559629
            44879610 44309612 43969617 43579639 42919694 43179895
            43329945 

MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0758 PM CDT Fri Aug 28 2026

Valid 290100Z - 291200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE GREAT
BASIN...TO THE CENTRAL ROCKIES AND NORTHERN PLAINS...

...SUMMARY...
Isolated strong to severe storms are possible across the northern
Plains, and from parts of the Great Basin and Desert Southwest into
the Rockies.

...Great Basin/Rockies...
Evening water vapor imagery showed an expansive area of high
pressure centered over the Four Corners with broad southwesterly
flow aloft ongoing over much of the Great Basin and Rockies. To the
west of the ridge, an upper low and broad trough were moving onshore
across the Pacific Northwest and CA respectively. Ahead of these
features, several weaker perturbations and a plume of mid-level
moisture were contributing to widely scattered thunderstorms over
the Great Basin and central Rockies this evening.

Despite limited buoyancy owing to expansive cloud cover, plentiful
monsoon moisture should continue to support widely scattered
high-based thunderstorms this evening and into the overnight hours.
At least isolated strong to severe gusts are possible owing to dry
low-levels suitable for strong downdrafts with the established
storms/clusters. This appears most likely from far eastern NV,
across northern UT, and into central WY where the air mass remains
the warmest.

...Northern Plains...
The first of the mid-level shortwave troughs embedded within the
broader southwest flow are expected to eject eastward over the
northern Plains tonight. As ascent from the wave overspreads a warm
front, the low-level jet is forecast to strengthen (40-50 kt),
supporting a broad area of low-level warm air advection across the
eastern Dakotas into MN/IA. Elevated storms should develop near the
front with moderate buoyancy and deep-layer shear supportive of
supercells. Some hail risk is possible with these storms overnight.
Given the increasing forcing for ascent, upscale growth into a
cluster or MCS is possible, which could result in a low-probability
risk for damaging gusts over southwest MN and adjacent northwest IA
through 12z Saturday.

...Mid Atlantic to the Southeast...
Several clusters of scattered thunderstorms remain ongoing ahead of
a weak front from VA to the northern Gulf Coast. These storms have
slowly weakened through the evening and should continue to do so
with the loss of diurnal heating. Ahead of the front, high PWAT
content (2-2.5 inches) may still support a sporadic downbursts with
the stronger clusters this evening. However, weak shear and waning
diurnal buoyancy suggest an organized or expansive severe threat is
unlikely.

..Lyons.. 08/29/2026