Severe weather fact sheet         

Logan County No. 1 in Illinois tornadoes

[March 09, 2007]  Facts from the National Weather Service, Lincoln:

The National Weather Service mission

The National Weather Service provides weather, hydrologic, and climate forecasts and warnings for the United States, its territories, adjacent waters and ocean areas, for the protection of life and property and the enhancement of the national economy. The NWS is the sole United States official voice for issuing warnings during life-threatening weather situations.

Hazardous weather impacts

• U.S. fatalities due to tornadoes have decreased from more than 110 per year in the 1950s through the 1970s to 57 per year since the implementation of Doppler radar in 1995 at more than 120 National Weather Service offices across the country.

• On average, the most weather-related fatalities over the past 30 years have been attributed to floods, with an average of 107; followed by lightning, 66; and tornadoes, 65.

Central and southeast Illinois severe weather statistics

• In 2006, nearly 83 percent of all severe weather events -- damaging winds, tornadoes and large hail -- in central Illinois had advance warning by the National Weather Service in Lincoln, with an average lead time of 18 minutes.

• Since Doppler radar has been installed at the National Weather Service office in Lincoln, nearly 83 percent of all severe weather events have had advance warning, with an average lead time of 17 minutes for the period from January 1996 through December 2006.

• This is a 30 percent improvement in accuracy and a five-minute increase in average lead time over the previous 10-year period, January 1986-December 1995.

• Of the 15 counties in Illinois with the most tornadoes, 11 are in central or eastern Illinois. These are Logan, No. 1; Macon, No. 2; McLean, No. 3; Sangamon, No. 4; Woodford, No. 6; Tazewell, No. 7; Champaign, No. 10; Piatt, No. 12; Douglas, No. 13; Coles, No. 14; and Mason, No. 15. (Data based on tornadoes from 1950 to 2006, normalized to 1,000 square miles)

• More than 2,300 volunteer weather spotters were trained in 26 central and eastern Illinois counties last year. About 700 were new trainees.

Economic impacts of weather forecasts and warnings

• National Weather Service implementation of storm-based warnings for smaller areas and portions of counties will result in a 70 percent reduction in false alarms. It is projected that this improvement will save businesses and the public in the United States nearly $100 million in sheltering costs each year (e.g., lost business, lost productivity).

• 33 percent of the United States gross domestic product, or nearly $3 trillion, is affected by weather and NOAA's National Weather Service forecasts.

• The average U.S. household pays only about $1.08 per month for NOAA's weather services.

• Average annual damage from tornadoes, hurricanes and floods in the U.S. is $11.4 billion.

• Economists have estimated that improved El Nino forecasts have resulted in annual savings of nearly $300 million for U.S. agriculture by altering planting decisions.

Visit www.weather.gov/lincoln for the latest weather and river forecasts, warnings, current conditions, radar and satellite imagery, and climate information.

[Text from file received from the National Weather Service, Lincoln office]

(Original PDF file) [To download Adobe Acrobat Reader for the PDF file, click here.]