Warn-on-Forecast

Thumb — The Warn-on-Forecast run at 17z on May 21, 2024, showing a high probability of low-level updraft helicity near Adair County three hours before the Greenfield tornado formed

The research project was started in 2016 in the National Weather Center in Norman, Oklahoma.^[5]

On May 16, 2017, a deadly EF2 tornado struck Elk City, Oklahoma. Before the tornado formed, meteorologists at the National Weather Service Norman, Oklahoma (NWS Norman) office saw storms form in Texas. NSSL, who works in the same building as NWS Norman, had a meteorologist embedded with the NWS Norman meteorologists. The Warn-on-Forecast system, which was being monitored by the NSSL meteorologist, noted a high chance of a tornado occurring in the Elk City area well before the tornado occurred. As a result, the National Weather Service issued a Significant Weather Advisory which stated, “Severe weather is likely with these storms as they move into Oklahoma and there is a high probability that tornado warnings will be issued.” Following the advisory being issued, the Elk City Emergency Manager, Lonnie Risenhoover, activated the tornado sirens to warn residents of Elk City nearly 30 minutes before the tornado struck. NWS Norman subsequently issued a tornado warning for Elk City, which was in place 28 minutes before the tornado struck. This was the first time WoFS influenced real time tornado warnings from the National Weather Service.^[6]

In May 2018, tests were conducted alongside meteorologists at the NWS Norman office.^[5]

On May 21, 2024, a violent EF4 tornado struck the city of Greenfield, Iowa. A few weeks after the tornado, the National Oceanic and Atmospheric Administration released details about an experimental warning system which was tested before and during the tornado. This new warning system, named Warn-on-Forecast System (WoFS), was created by the Hazardous Weather Testbed housed in the National Weather Center in Norman, Oklahoma. During the experiment and test, the WoFS gave a high indication of “near-ground rotation” in and around the area of Greenfield, Iowa between 2-4 p.m. According to the press release, 75-minutes later, the violent EF4 tornado touched down. Scientists with the National Severe Storms Laboratory were able to give local National Weather Service forecasters a 75-minute lead time for the tornado.^[7]^[8]

The reintroduction of the TORNADO act into the 119th United States Congress includes the implementation of the Warn-on-Forecast system into normal forecasting operations, as prior to this it has only been used during large-scale severe weather events.^[9]

On April 4, 2025, Bloomberg and Axios reported that the website of the National Severe Storms Laboratory, which runs forecast models and hosts the Warn-on-Forecast cloud viewer, was set to be shut down at midnight on April 5 as a result of contract terminations at NOAA and a directive to NOAA to cut all IT-related spending by 50%. This was later pushed back to July 31, following a renewal of a contract with Amazon Web Services.^[10]

Timeline

External links

References

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