Mesoscale Discussion 1236
NWS Storm Prediction Center Norman OK
0716 AM CDT Wed Jun 12 2024
Areas affected...northeast Nebraska...eastern South
Dakota...southwest Minnesota...and northwest Iowa
Concerning...Severe potential...Watch unlikely
Valid 121216Z - 121345Z
Probability of Watch Issuance...20 percent
SUMMARY...An isolated large hail threat is expected to continue this
morning.
DISCUSSION...Ongoing elevated thunderstorm activity across eastern
South Dakota, western Minnesota, and northern Nebraska has been
somewhat more robust than anticipated, particularly amid relatively
weak instability (500 to 1000 J/kg MUCAPE). This is likely aided by
the 40 to 45 knot low-level jet which continues to intensify based
on the OAX, LNX, and FSD VWP. In addition, strong deep layer shear
(50+ knots) supports supercells and a threat for large hail with the
more robust/longer-lived updrafts. Storms are forming on the eastern
edge of the instability plume and moderately strong storm speeds are
leading to them moving east of this better instability. However,
some thunderstorms may continue to develop on the western periphery
of this ongoing activity where greater instability is present. If
storms had a longer residence time before exiting the greater
buoyancy, a severe thunderstorm watch may be necessary. However, the
threat is expected to remain somewhat isolated and only for a few
more hours. Therefore, a watch is not anticipated.
..Bentley/Hart.. 06/12/2024
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...MPX...DMX...FSD...OAX...ABR...LBF...UNR...
LAT...LON 45239879 45569648 45359496 44379466 42469539 42149693
42199877 42449920 43149980 43660016 44739973 45239879