Four tornadoes struck Minnesota on Sunday, July 28th, producing damage in McLeod, Washington, and Chisago Counties.
The tornadoes formed in a somewhat unusual environment, within a mass of steady precipitation and clouds that had been leftover from morning showers and thunderstorms. The air was very humid, and as it warmed gradually during the early afternoon, some of the showers intensified enough to acquire low-level rotation and produce tornadoes. The parent cells responsible for the tornadoes produced little or no lightning, no hail, no downburst wind damage, and only moderately-heavy rainfall; unlike more classical "supercell" thunderstorm situations, the tornadoes were the only hazard. This situation shared some similarities with the tornadoes of August 19, 2009.
Despite the unconventional meteorological set-up, and unlike those from August of 2009, these tornadoes appeared large and quite menacing. As pointed out by the Twin Cities National Weather Service office, however, the tornadoes may have grown wide because of the the abundance of moisture available. Fortunately, their size did not translate to massive amounts of damage. Two of the tornadoes were rated EF-1, and two were rated EF-0. One additional EF-1 and one EF-0 tornado struck Wisconsin as well.
For descriptions, radar animations, and photos of the tornadoes, please see the summary produced by the National Weather Service forecast office in Chanhassen.
Last modified August 5, 2019