Reset Application (All timestamps are displayed in UTC)
Hail Size:
LSR Buffer: km
Warning Buffer: degrees
Warning Type: TornadoSvr T'stormMarineFlash Flood (2008+)
LSR Type: TornadoWind DamageHailWind GustMarineFlash Flood (2008+)
When possible, verify SVR warnings against issuance WIND...HAIL tag
When possible, limit considered warnings to your hail/wind threshold

IEM Cow (NWS Storm Based Warning Verification)

Data presented here is unofficial and should be used for educational purposes only. This application allows you to view warnings and storm reports issued by a Weather Forecast Office (WFO) for a period of time of your choice. The application attempts to automatically provide verification numbers for the warnings issued.

This application works for dates after 8 June 2005.

Storm Based Warnings

On the first of October 2007, the National Weather Service began issuing warnings for tornados, severe weather, floods, and marine hazards on a storm by storm basis. Previously, the warnings were issued for an entire county. This application attempts to provide verification statistics for these storm based warnings.

The images shown are taken from the NWS Storm Based Warnings website.

Related links:

Verification Methodology

The map on the left illustrates some of the spatial statistics the Cow produces. The following is a brief description of these values.