Independent Evaluation of National Oceanic and Atmospheric Administration's National Weather Service Tornado Forecasting and Warning Performance

Between fiscal years (FY) 2008 and 2022, the NWS reported approximately 1,400 tornadoes on average each year. The majority of tornadoes in each year were rated EF0 or EF1 (1,170 tornadoes on average per year) and caused light to moderate damage. Severe to devastating tornadoes are rare events—on average, the NWS reported 44 EF3+ tornadoes per year during the same period.

Section 103 of the Weather Research and Forecasting Innovation Act of 2017 supported performance improvements related to the National Oceanic and Atmospheric Administration’s (NOAA) weather forecasting and prediction of high-impact weather events, and mandated the creation of a Tornado Warning Improvement and Extension Program (TWIEP). The TWIEP’s goal is to “to reduce the loss of life and economic losses from tornadoes through the development and extension of accurate, effective, and timely tornado forecasts, predictions, and warnings, including the prediction of tornadoes beyond one hour in advance.” In 2019, NOAA’s Office of Oceanic and Atmospheric Research (OAR) and National Weather Service (NWS) submitted a TWIEP Plan to Congress which identified six key short-term goals and four milestones to complete by 2023, and four long term goals to complete by 2029, in pursuit of the TWIEP’s main objective.

The Department of Commerce’s (DOC) Office of Inspector General (OIG) has oversight responsibility for NOAA’s NWS. In August 2023, the DOC OIG contracted with the Institute for Defense Analyses (IDA) to assess NWS tornado forecasting and warning performance since Congress passed the Weather Act and identify potential opportunities for enhanced effectiveness. This presentation will present the findings and recommendations found as a result of this independent evaluation.