Cold Pool Amalgamation Sets Stage for High Plains Wind Clusters — SevereWX

Thunderstorms firing off the high terrain of southeastern Wyoming and central Colorado are shifting east into the central High Plains this afternoon and evening. SPC's Mesoscale Discussion 1558 highlights how steep low-level lapse rates and a dry, well-mixed boundary layer will drive efficient evaporative cooling, leading to merging cold pools. This setup favors upscale growth into linear clusters or segments, ramping up the threat for damaging wind gusts to 65-80 mph and hail of 1-1.75 inches.

A subtle mid-level perturbation and southeasterly upslope flow are boosting storm coverage, with westerly flow aloft pushing convection eastward. While effective shear is modest at 25-30 knots, a surface moisture gradient—dewpoints rising from the 40s F near the Foothills to the low-to-mid 60s F in western Kansas and Nebraska—could aid slow storm organization and intensification.

Severe thunderstorm watch issuance is likely within the next couple hours (80% probability), covering parts of Nebraska, Kansas, Colorado, and Wyoming. The most probable peak threats point to those strong winds and golf ball-sized hail as storms progress into the evening.

Areas at risk span from the Nebraska Panhandle through northwest Kansas, northeast Colorado, and southeast Wyoming. Timing hinges on storm clustering, but the severe potential looks solid.

Stay prepared: Monitor radar updates, have a severe weather plan, secure outdoor items, and seek shelter if storms approach. Check local NWS offices (LBF, DDC, GLD, PUB, BOU, CYS) for the latest.