Monitoring of concurrent, co-located tornado and flash flood (TORFF) warnings

Below is the most recent image showing overlapping tornado and flash flood warning polygons thus far in 2026. Warnings are shown if they overlap in space and are valid within 30 minutes of one another, calculated as described in Nielsen et al. (2015, Weather and Forecasting). The images are updated once per day at approximately 1200 UTC. The images are zoomed in on the region where overlapping TORFF warnings are most frequently observed.

Images last updated 0931 UTC Wednesday May 13 2026. (click image to embiggen)

The ten most recent TORFF overlapping warnings in 2026 are:

MEG issued TOR warning at: 202604290051 and FF warning at: 202604290115
LZK issued TOR warning at: 202604290048 and FF warning at: 202604290115
IND issued TOR warning at: 202604280252 and FF warning at: 202604280310
LSX issued TOR warning at: 202604280115 and FF warning at: 202604280059
LSX issued TOR warning at: 202604280022 and FF warning at: 202604280016
LSX issued TOR warning at: 202604272341 and FF warning at: 202604272347
LSX issued TOR warning at: 202604272301 and FF warning at: 202604272232
ILX issued TOR warning at: 202604272242 and FF warning at: 202604272250
ILX issued TOR warning at: 202604272240 and FF warning at: 202604272250
ILX issued TOR warning at: 202604272218 and FF warning at: 202604272220

Download the text file with the details of this year's overlapping warnings.

Time series of overlapping warning counts:

All TORFF Warning Intersections (n=4173) from 2008-2019:

Map of "Verified" TORFF Events from 2003-2018:

"Verified" TORFF events are identified by finding intersections between flash flood local storm reports (LSRs) and official tornado paths that were reported within three hours of one another, allowing for up to a 50 km spacing between the two. Five different spacing thresholds are tested from 10 km to 50 km, where the 10 km (50 km) spacing creates the most (least) conservative event totals. Between 25 and 75 "verified" TORFF events occur on average per year, depending on spatial threshold chosen. Discussion of the specific methods can be found in Nielsen (2019) and Henderson et al. (2020, Weather and Forecasting).

Select a Spatial Buffer:

TORFF Warning Intersections for Select U.S. Tropical Cyclones:

Select a Storm:

This research is sponsored by NOAA grant NA15OAR4590233, in support of the 2016 VORTEX-SE field campaign.

DISCLAIMER: The images and data on this site are intended for meteorological education and research purposes and, although they should generally be up to date, are not monitored at all times. Do not use for making decisions where money or lives are at stake. For official forecasts and warnings, visit the National Weather Service.