Mesoscale Discussion 1048
NWS Storm Prediction Center Norman OK
0213 PM CDT Tue Jun 09 2026
Areas affected...much of the western Dakotas
Concerning...Severe potential...Watch likely
Valid 091913Z - 092145Z
Probability of Watch Issuance...80 percent
SUMMARY...Intensifying thunderstorm development appears increasingly
probable through 4-6 PM CDT, accompanied by the risk for large hail
and potential for increasingly widespread strong to severe wind
gusts.
DISCUSSION...Beneath a plume of warm and capping elevated
mixed-layer air (including +10-12 C around 700 mb), surface
troughing continues to deepen across much of the western Dakotas,
downstream of larger-scale mid/upper troughing overspreading the
northern Rockies. The boundary-layer is only modestly moist, but
low-level lapse rates are steepening with continuing insolation and
mixing, and it appears that profiles are becoming supportive of CAPE
on the order of 1000-2000 J/kg.
As the leading edge of mid-level cooling begins to suppress the
elevated mixed-layer within the next few hours, the initiation of
thunderstorm development appears probable. As this occurs, the
environment appears conducive to the development of severe hail and
strong downbursts in stronger storms. Thereafter, through 21-23Z,
convection with expanding northeastward/eastward propagating cold
pools likely will continue to grow upscale and organize, gradually
acquiring inflow of increasingly moist and potentially unstable air
advecting northwestward into the Missouri Valley. As this occurs,
strong to severe surface gusts may become more widespread, along
with perhaps at least some increase in potential for tornadoes along
the western flank of a 30+ kt southerly 850 mb jet.
..Kerr/Mosier.. 06/09/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...ABR...BIS...UNR...
LAT...LON 48100245 47860083 47300046 45730067 44870114 44440184
44480272 46490262 48100245
MOST PROBABLE PEAK TORNADO INTENSITY...85-110 MPH
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...2.00-3.50 IN
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