On October 18th, 2018, a strong derecho moved along the East Coast. But the unusual thing was that the cloud tops associated with the derecho didn't exceed 25,000 feet. The derecho caused 3 deaths, 193 injures, $1,358 million dollars in damage, and winds sometimes in excess of 85 mph.
How It Formed Edit
It was reported that how the derecho formed was there were very strong jet stream winds of 85 mph at the first 10,000 feet above ground, combined with moisture from the Gulf of Mexico, and a very strong cold front. But it was also known that the CAPE values were very low, even for ordinary thunderstorms. CAPE values didn't reach much above 250. This was the reasons that the cloud tops were low, and also, the reason why there was barely any thunder or lightning reported.