MD 1229 CONCERNING SEVERE POTENTIAL...WATCH LIKELY FOR WESTERN NEBRASKA...NORTHEAST COLORADO...AND NORTHWEST KANSAS
Mesoscale Discussion 1229
NWS Storm Prediction Center Norman OK
1251 PM CDT Sun Jun 21 2026
Areas affected...Western Nebraska...northeast Colorado...and
northwest Kansas
Concerning...Severe potential...Watch likely
Valid 211751Z - 211945Z
Probability of Watch Issuance...80 percent
SUMMARY...Conditions are being monitored for thunderstorm initiation
across the NE/CO/KS tri-state region, which may be within the next
1-2 hours. Watch issuance is likely at some point this afternoon.
DISCUSSION...Latest GOES imagery and surface observations show the
early stages of deepening cumulus in proximity to a diffuse surface
low and along low-level trough axes/confluence zones. This comes as
upper-level ascent associated with an upstream wave over WY
continues to migrate southeast and as temperatures begin to warm
into the upper 70s and low 80s. Recent RAP mesoanalyses continue to
show some lingering inhibition across the effective warm sector
(where dewpoints remain the 50s to low 60s), but forecast guidance
suggests that this inhibition will be largely removed as
temperatures continue to warm into the low to mid 80s.
These solutions also depict initiation of deep convection by around
20 UTC; however, based on the latest GOES trends and current
temperatures, initiation may occur slightly earlier across western
NE and along the NE/CO border. Once initiation does occur,
convection will mature within an environment favorable for splitting
supercells capable of very large hail given mostly straight,
elongated hodographs across the region and sufficient mixed-layer
buoyancy (MLCAPE of around 1500-2000 J/kg). Consequently, watch
issuance is expected in the coming hours as initiation becomes more
probable.
..Moore/Hart.. 06/21/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...LBF...GLD...BOU...CYS...
LAT...LON 42060288 42400254 42560212 42510158 42230122 41870097
41010074 40310062 39760062 39320073 39120096 38900134
38930181 39090223 39430251 39780266 40440285 41010291
41700300 42060288
MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN
Read more