Outbreak of tornadoes across North Dakota
1-minute GOES-19 “Red” Visible (0.64 µm, left) and “Clean” Infrared Window (10.3 µm, right) images with time-matched (+/- 3 minutes) SPC Storm Reports plotted in red/blue, from 1730 UTC on 14 September to 0022 UTC on 15 September [click to play animated GIF | MP4]
1-minute Mesoscale Domain Sector GOES-19 (GOES-East) Visible and Infrared images (above) included time-matched (+/- 3 minutes) plots of SPC Storm Reports — which showed supercell thunderstorms that produced a south-to-north oriented swath of at least 12 tornadoes across central North Dakota on 14 September 2025. With this outbreak, a new record was set for the number of tornadoes in North Dakota during a calendar year.
A plot of rawinsonde data from Bismarck, North Dakota at 1800 UTC on 14 September (below) indicated that the Most Unstable (MU) air parcel’s Equilibrium Level (EL) was at an altitude near 12 km, where the air temperature was around -55C (which closely corresponded to the coldest cloud-top infrared brightness temperatures seen in GOES-19 Infrared imagery).
Plot of rawinsonde data from Bismarck, North Dakota at 1800 UTC on 14 September [click to enlarge]
GOES-19 Visible and Infrared images at 2231 UTC (below) included plots of three SPC tornado reports (T) that were received very near that time — plotted at both their observed surface locations, and at their “parallax-corrected” location (assuming a mean cloud-top height of 12 km). It can be seen that that the parallax-corrected locations were moved NW, closer to the parent supercell thunderstorms.
GOES-19 Visible (left) and Infrared (right) images at 2231 UTC on 14 September, with SPC Storm Reports of three tornadoes plotted at their surface locations as well as at their “parallax-corrected” cloud-top locations [click to enlarge]
Another important ingredient helping to produce this tornado outbreak was the presence of climatologically high values of Precipitable Water (below) — the value of 1.39 inch derived from 1800 UTC Bismarck rawinsonde data was above the 90th percentile for 14 September, and not far below the daily maximum value of 1.68 inch.
Plot of annual Precipitable Water climatology for all Bismarck soundings — with the values for 14 September highlighted [click to enlarge]
Hourly SPC Mesoscale Analyses of Precipitable Water (below) depicted the broad corridor of high moisture that was being transported northward across the Dakotas on 14 September.
Hourly SPC Mesoscale Analysis of Precipitable Water across the north-central US, from 1500 UTC on 14 September to 0000 UTC on 15 September [click to play MP4 animation]