Two years ago today, one of the most infamous supercells in recent memory formed in one of the most incredible environments in recent memory. The Pilger, Nebraska supercell is one of the most productive and powerful supercells I’ve ever seen, as the storm produced four EF-4 tornadoes. FOUR. That is absolutely insane.
The set up for this was really favorable, too. A long wave trough at the 500 mb level was centered across the northwestern coast of the US, with west-southwesterly flow across eastern Nebraska. Below that, the region was seeing southwesterly to southerly flow, advecting very warm and moist air into the region.
Surprisingly enough, atmospheric flow was actually fairly impressive, with relatively strong flow at all levels of the atmosphere from the surface and on up. Additionally, shortwaves were rotating through the eastern side of the longwave trough, moving northeastward.
By the afternoon, the surface, and the rest of the boundary layer, was incredibly moist and unstable. Dewpoints were in the low to mid 70s across the region, with temperatures in the upper 80s. This yielded one of the most impressive atmospheric soundings I have ever seen.
A sounding just basically just a vertical look at temperature, wind and moisture in the atmosphere. It is collected by a balloon released twice daily, and at special times for big events. I have never seen a sounding with so much instability and wind shear all in one. It is wild, and was primed for a crazy supercell. All of this, in conjunction with shortwaves rotating through the region, sparked off a supercell that produced one of the most impressive families of tornadoes in recent memory.
The Storm Prediction Center had an excellent forecast for the day, and predicted the region of the tornadoes with excellent accuracy. Check out some of the wild videos of the Pilger tornado.
This supercell was truly a marvel of the atmosphere, and is just fascinating. The set up, and eventual development of the Pilger tornado, is one of my favorite events to read about and learn about. This day was likely somber for the people who lost home and property, so keep them in your thoughts and prayers as they likely struggle with the memories of that day.