The National Weather Service in Grand Forks has, through Friday, Sept. 4, issued 303 severe thunderstorm warnings and 42 tornado warnings for a total of 345 combined severe weather warnings this summer. This is the highest number of combined warnings since 2005, when there were 355 warnings issued. The highest number of combined severe thunderstorm and tornado warnings since the beginning of polygon-shaped storm warnings (rather than county-based) was 452 in 2001.
The high number of storms this summer is due to the persistent positioning of the jet stream over our region allowing for frequent warm and humid air intrusions underneath fast-moving waves of air aloft, creating both the dynamic and thermodynamic energy necessary for thunderstorm development. From the first week of June through the first week of September, not a single week passed without at least one or two days of severe weather.