SPC MD 1214

MD 1214 CONCERNING TORNADO AND SEVERE THUNDERSTORM WATCHES 357...358... FOR PORTIONS OF FAR EASTERN COLORADO...EXTREME SOUTHWESTERN NEBRASKA...AND WESTERN KANSAS Mesoscale Discussion 1214 NWS Storm Prediction Center Norman OK 0542 PM CDT Sat Jun 20 2026 Areas affected...portions of far eastern Colorado...extreme southwestern Nebraska...and western Kansas Concerning...Tornado and Severe Thunderstorm Watches 357...358... Valid 202242Z - 210045Z The severe weather threat for Tornado and Severe Thunderstorm Watches 357, 358 continues. SUMMARY...All severe hazards are possible over the next couple of hours. However, ongoing storms should merge into an MCS and support a potential severe wind swath between 00-04Z. A few gusts may reach 85-100 mph. DISCUSSION...Multiple HP supercells, with a history of hail 1-3 inches in diameter, and measured gusts up to 90 mph (89 mph measured by NSSL mobile unit), are in the process of gradually merging along the KS/NE border, with a convective outflow boundary noted across Cheyenne into Rawlins Counties. Over the next couple of hours, the more intense and discrete updrafts will persist with a severe hail threat, with a few stones exceeding 2 inches in diameter. While storms may become outflow dominant, an additional tornado or two may still occur given the amount of low-level shear concentrated along the warm front. Over the next few hours, the supercells are expected to merge into a cold-pool-driven MCS, which will surge southward this evening. Given preceding 8-8.5 C/km mid-level lapse rates, and a corridor of 50-60 kt bulk shear vectors oriented roughly normal to the expected MCS leading-line orientation, the MCS could become highly organized and produce a severe wind swath. This swath will most likely occur somewhere in the 00-04Z period, containing abundant gusts in the 60-70 mph range, with the strongest gusts possibly reaching 85-100 mph, as suggested by some of the latest HRRR and WoFS runs. ..Squitieri.. 06/20/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...ICT...GID...DDC...GLD...PUB...BOU... LAT...LON 37100100 37220202 37360271 37460296 37660304 38750300 39130299 39800287 40200216 40310147 40280061 40059973 39779902 39229880 38349877 37749879 37329960 37150024 37100100 MOST PROBABLE PEAK TORNADO INTENSITY...100-125 MPH MOST PROBABLE PEAK WIND GUST...85-100 MPH MOST PROBABLE PEAK HAIL SIZE...2.00-3.50 IN Read more