Derecho is related to a squall line the way a hurricane is related to a tornado. A Derecho is considerably larger, several orders of magnitude more energy. A derecho can be an arc several hundreds of miles across with winds of hurricane force. The winds that flattened the tulip poplar in the above post were in excess of 90 miles an hour. There was a derecho spring 2020 that the arc extended from just north of Saint Louis Missouri north into central Minnesota. The portion moving across Iowa had straight line winds over 110 miles per hour and did many millions of dollars worth of damage to buildings and flattened crops, even orchards were flattened. The same derecho came through Joliet, Chicago and Milwaukee later that day, but had already expended much of its energy, we only had 60 mile per hour winds at the Waukegan airport which is my closest weather station. A derecho can be a fierce storm. Thankfully, they are generally short lived. The worst will pass in less than an hour.
A squall line will have 40 mile per hour winds, and might be 50 miles in length. A derecho is just a whole separate creature, orders of magnitude more destructive.
Its a weather word, like "polar vortex", that has been around for a long time, but recently has come into "common use".
