ACUS11 KWNS 201911

SWOMCD

SPC MCD 201911 

NEZ000-KSZ000-COZ000-202115-



Mesoscale Discussion 1212

NWS Storm Prediction Center Norman OK

0211 PM CDT Sat Jun 20 2026



Areas affected...parts of eastern Colorado...southwestern

Nebraska...western Kansas



Concerning...Severe potential...Watch likely 



Valid 201911Z - 202115Z



Probability of Watch Issuance...80 percent



SUMMARY...Intensifying scattered thunderstorm development

increasingly probable by 2-4 PM MDT, with a few supercells evolving

thereafter.   This may be accompanied by increasing potential for a

couple of strong tornadoes, mainly in a corridor west through south

of the Imperial, NE vicinity toward early evening.



DISCUSSION...Beneath a plume of very warm (including 14-16 C+

temperatures around 700 mb) elevated mixed-layer advecting east of

the southern Rockies, a surface low is beginning to develop within

rapidly deepening surface troughing across eastern Colorado.  This

is coinciding with strong boundary heating and deep mixing, to the

south of a zone of strengthening differential surface heating

evolving to the north of the developing low, across parts of

northwestern Kansas into the southern slopes of the Cheyenne Ridge. 



Along and to the cooler side of this boundary, higher boundary-layer

moisture content and potential instability (including CAPE exceeding

2000 J/kg) are forecast to be maintained through the afternoon. 

Even to the south of this boundary, the more deeply mixed

boundary-layer is forecast to become characterized by modest (but

increasing across the plains toward the Kansas state border) CAPE,

as convective temperatures are approached later this afternoon.



Inhibition may remain strong along the zone of differential heating,

but forcing for ascent associated with focused low-level convergence

and warm advection may eventually contribute to isolated supercell

development.  In the presence of strengthening deep-layer and

low-level shear, this may be accompanied by increasing potential for

a strong tornado or two, in addition to large hail, by early

evening, if not earlier.



Otherwise, high-based convective development now underway across and

to the east of the higher terrain is expected to continue to spread

eastward across the plains and intensify, with scattered

thunderstorms increasingly probable by 20-22Z.  This will be

accompanied by increasing potential for large hail, locally damaging

wind gusts, and perhaps at least some risk for a couple of tornadoes

as well.



..Kerr/Hart.. 06/20/2026



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



ATTN...WFO...LBF...DDC...GLD...PUB...BOU...CYS...



LAT...LON   41060388 41090243 40420074 39400063 38270150 37160181

            37170326 37510356 38450320 39330408 40290403 41060388