A team of experts from NOAA’s National Weather Service (NWS) released a service assessment today on the performance of its forecast operations during the severe weather outbreak that struck portions of 19 states in May 2003, resulting in 39 deaths and nearly 400 tornadoes during a six-day period.

The report found the teamwork between the local weather forecast offices and the National Centers for Environmental Prediction’s (NCEP) Storm Prediction Center (SPC) enabled the meteorologists to anticipate the tornado events, adjust staffing appropriately to handle the events, and inform the public, emergency managers and media of the potential for severe weather and the likely impacts. As a result, hazardous weather outlooks, issued as early as six days in advance, warned of the potential for severe weather.

“Tornado Warning and Watch lead times are key performance measures that demonstrate the National Weather Service’s ability to get reliable and accurate information in the hands of the public, so that we can meet a core NOAA mission to help save lives” said retired Navy Vice Adm. Conrad C. Lautenbacher, Ph.D., undersecretary of commerce for oceans and atmosphere and NOAA administrator. “Several people interviewed for the assessment indicated there were no surprises in the outlooks, statements, watches and warnings issued before and during the event. This is critical to protecting lives and property.”

The average lead time for all tornado warnings was 19 minutes. Tornado watches, issued by SPC, had average lead times of two hours and three minutes. All of these values are better than national averages.

“Customers and partners said they were extremely satisfied with the services they received before and during this record-setting outbreak, and often expressed their gratitude for the high level of performance provided,” said Jim Purpura, service assessment team leader and meteorologist in charge of the National Weather Service (NWS) Forecast Office in San Diego, Calif.

The survey was conducted by a team of NOAA personnel, assembled from duty stations around the United States, who created a detailed time line of the weather events through discussions with forecasters and a review of data. The team then interviewed emergency managers, city officials, media, residents and other constituents who were affected by the weather events to determine the timeliness and effectiveness of the warnings that were issued by the NWS forecast offices.

Severe weather assessments are a routine internal review that looks at the quality of services provided to NWS customers during major weather events. The assessment, which covers data compiled by the assessment team as of July 20, 2003, verified there were 393 tornadoes during the unprecedented series of tornado outbreaks. Previously, the most active week of tornadoes on record was May 12-18, 1995, when 171 tornadoes were reported.

Outbreaks produced violent (F4 on the Fujita scale of intensity from 1 to 5) tornadoes on May 4 in the county warning areas served by the weather forecast offices in Kansas City and Springfield, Mo., as well as Memphis, Tenn., and on May 6 in the Paducah, Ky., area. The report reviewed two tornadoes that struck the Oklahoma City area on May 8 (F4) and May 9 (F3) where no one was killed, even though the back-to-back days of tornadoes moved through densely populated areas.

“We also reviewed the performance of NOAA’s SPC in Norman, Okla., which is responsible for issuing severe weather outlooks and watches. Due to the sheer intensity and number of tornadoes during that time, the assessment team chose to limit the scope of our findings in the report to May 4, 6, 8 and 9, at SPC and the five forecast offices,” Purpura said.

As a result of the severe weather assessments, best practices are identified for use throughout the NWS. Service lapses, if any, are noted and recommendations for corrective actions were made. The report identifies nine recommendations for improvements within the NWS severe weather warning process. The service assessment report includes key findings and recommendations, ranging from improvements to future weather operations and warnings, to strengthening cooperation with other agencies on damage surveys.

NOAA’s National Weather Service (NWS) is the primary source of weather data, forecasts and warnings for the United States and its territories. NOAA’s NWS operates the most advanced weather and flood warning and forecast system in the world, helping to protect lives and property and enhance the national economy.

The Commerce Department's National Oceanic and Atmospheric Administration (NOAA) is dedicated to enhancing economic security and national safety through the prediction and research of weather and climate-related events and providing environmental stewardship of our nation’s coastal and marine resources.

On the Web:

NOAA: http://www.noaa.gov

NOAA National Weather Service: http://www.nws.noaa.gov

Service Assessment Reports: http://www.nws.noaa.gov/om/assessments/index.shtml