ACUS11 KWNS 090418
SWOMCD
SPC MCD 090418
MOZ000-IAZ000-KSZ000-NEZ000-090615-

Mesoscale Discussion 1874
NWS Storm Prediction Center Norman OK
1118 PM CDT Sat Aug 08 2026

Areas affected...Eastern Nebraska into southwest Iowa and northern
Missouri

Concerning...Severe potential...Watch unlikely

Valid 090418Z - 090615Z

Probability of Watch Issuance...20 percent

SUMMARY...Elevated thunderstorms may pose a risk of isolated large
hail and severe gusts through the overnight hours for parts of far
eastern Nebraska into southwest Iowa and northern/northwest
Missouri. The severe risk is expected to generally remain
sufficiently isolated to preclude the need for a watch.

DISCUSSION...Convection has been percolating across southwest IA
over the past hour, and is largely being driven by modest isentropic
ascent between 925-850 mb on the eastern fringe of a low-level
thermal ridge where capping is weaker. Although this activity is
displaced to the east of greater instability over NE/KS, latest
mesoanalysis estimates and the 00 UTC OAX RAOB show MUCAPE values of
2000-3000 J/kg from eastern NE into northern MO. Additionally,
mid-level winds on the order of 50 knots are supporting effective
bulk shear values of similar magnitude oriented along the buoyancy
gradient. This thermodynamic and kinematic environment is conducive
for organized severe convection, and recent radar trends appear to
reflect this - a few deeper cores within the cluster have exhibited
vertical ice signatures consistent with severe hail.

The expectation over the next several hours is for additional
thunderstorm development across southwest IA into adjacent portions
of north/northwest MO with additional re-development probable across
far eastern NE based on latest GOES IR trends. Storm motions along
the zone of initiation will promote destructive storm interactions
that will likely limit the overall propensity for long-lived/intense convection. However, given the ambient environment a few
strong/severe thunderstorms appear likely through the early morning
hours - mainly posing a threat for large hail and perhaps severe
gusts. Recent RRFS solutions appear to be capturing this overall
signal well (even if a little delayed) and suggest the overall
severe threat should be isolated in nature, but could persist to
around 12 UTC.

..Moore/Mosier.. 08/09/2026

...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fjg!9FyHJGXt2nTzmB9LzNkPp0ShQQAjvyLl7PWJqvJ7yvd0Nm-KtmEW1Rifix3tfQSY5zo6uL6jfYUZxSBdaDESvyu0RKo$ for graphic product...

ATTN...WFO...DMX...EAX...OAX...TOP...

LAT...LON 42189656 42199618 40989335 40589324 40039336 39689376
39509414 39529457 39939530 40989676 41309706 41579717
41929710 42189656

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


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--- scorpsmtpd
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