At least four derechos have taken place so far in 2020, an unusually high number for a relatively rare severe weather event.

Derechos are long lines of powerful, wind damage-producing thunderstorms that cover plenty of ground. According to the Storm Prediction Center, a derecho has to travel at least 250 miles, regularly producing winds in excess of 58 mph, with occasional gusts topping 75 mph.

It all started in late April, when an overnight derecho moved south from Missouri to the Gulf Coast, traveling more than 500 miles as it rocked the South with strong winds, large hail and even an EF-2 tornado in Oklahoma.

A deadly derecho moved through the South on May 3rd, killing an off-duty firefighter in Spring Hill, Tennessee. It traveled more than 750 miles and lasted nearly 13 hours, first starting in Kansas before finally petering out in eastern Tennessee.

On June 3rd, a huge line of wind producing storms marched through Pennsylvania and New Jersey, knocking out power to more than a quarter million and leading to winds as high as 93 mph in coastal New Jersey. Philadelphia gusted to 67 mph during this damaging derecho.

And in the first weekend of June, a powerful derecho took place in a part of the country that rarely sees them: the west. Starting in southern Utah and blasting through Colorado, Nebraska, Wyoming, Nebraska and the Dakotas with winds in excess of 100 mph at times, this violent line led to hundreds of thousands of power outages in those six states.