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1974: Now vs. Then:

Even in today’s record books, the resultant toll of over 110 fatalities from the Super Tornado Outbreak in the Tennessee valley region remains one of the largest number of casualties from such a weather related disaster. When searching for an explanation as to why, the answer is clear. From technology to communications and the science of meteorology itself, many things have continuously changed since April 3, 1974. Back then, radar and satellite imagery was not nearly as effective as it is today in a modernized National Weather Service. New satellite, Doppler radar and other severe weather forecasting techniques have greatly improved the warning lead times for tornadoes to greater than 12 minutes compared to barely a minute lead time in the mid 1970s.

Communication has also greatly improved since April 3, 1974. NOAA Weather Radio has greatly expanded across the area as a result of the tornado outbreak. Media, including radio, television and newspaper have all greatly increased awareness to severe weather and we now have many more ways to receive warnings than we did in 1974.

Today, NOAA’s National Weather Service (NWS) is a leader in the most effective and sophisticated weather warning system in the world. Thanks to years of research and modern technology, forecasters at NOAA’s Storm Prediction Center (SPC) issue forecasts outlining the most likely locations for the development of tornadoes and other severe weather 48 hours in advance, then fine-tune the forecast as the potential for inclement weather draws near. Using GOES satellite imagery, current surface observations, upper-air data, and computer forecast models, the meteorologists at SPC issue Severe Thunderstorm and Tornado Watches when severe weather is expected a few hours out.

From there, the local NWS Weather Forecast Offices (WFO’s), such as offices in Huntsville, Birmingham and Mobile, continuously monitor WSR-88D Doppler Radar time-lapse imagery on sophisticated AWIPS Workstations to determine a storm’s severe potential. An invaluable resource to the radar operator’s final warning decision is the steady stream of reports from a network of trained and dedicated SKYWARN spotters, emergency managers, local law enforcement, and amateur radio "ham" operators.

When severe weather is either spotted or indicated on radar, the WFO radar operator issues a Severe Thunderstorm or Tornado Warning via WarnGen to alert the public to the imminent or existing threat of severe weather. As soon as the warning is disseminated, special tones are broadcast on NOAA Weather Radio in conjunction with the warning message—alerting the public to the impending threat to life and property. Meanwhile, various television and radio stations occasionally interrupt regular programming in order to communicate the NWS warning information to a large segment of the country’s population. During the entire process, it takes a tremendous amount of coordination between government and private entities to ensure the best possible warning coverage.

After a severe weather episode, the NWS takes an active role in surveying locales most devastated and compiling information on the storms for research and climatological purposes. Newspapers and broadcasts from radio and television keep local residents updated on storm damage and clean-up efforts. The driving force behind the disaster relief process includes such organizations as the Federal Emergency Management Agency (FEMA) and the American Red Cross. Together, these two agencies bring necessary relief supplies to storm victims, assist in clean-up efforts, and are often instrumental in obtaining state and federal funds to accelerate the clean-up efforts.

Thus, through technological advancements, improved communications, and dedicated scientific research, a large death toll of over 100 people like the 1974 tornado outbreak in the Tennessee valley from such a disaster is highly improbable today—but it is not impossible, especially if the tornado were to strike a highly populated area. Of course, the present warning system is not perfect, as evidenced by sometimes late or missed watches and warnings. However, we have obviously come a long way in the past 30 years! Through a continued cooperation between the NWS, FEMA, the American Red Cross, researchers, emergency managers, spotters, the media, and all concerned entities, the current warning system will undoubtedly experience significant improvements over the next 75 years and beyond.

Following is a description of each facet of the modernized National Weather Service operations and technology mentioned in the preceding text.

AWIPS – Advanced Weather Interactive Processing System. State-of-the-art NWS computer system integrating automated weather observations, satellite imagery, radar data, and numerical model forecasts into forecaster workstations. There are currently 134 AWIPS Workstations located at numerous Weather Forecast Offices and 13 River Forecast Centers across the United States.

Computer forecast model – A numerical projection of future weather conditions derived by using current weather data in hundreds of mathematical computations. The computations are performed on supercomputers at NOAA’s National Centers for Environmental Prediction (NCEP) in Silver Spring, Maryland. Currently, there are several forecast models in existence, including the NGM, ETA, AVN, MRF, and RUC.

GOES – Geostationary Operational Environmental Satellite. A geostationary satellite rotates at the same rate as the earth, remaining over the same spot above the equator. At any given time, there are two GOES satellites in orbit over the Atlantic and Pacific Oceans. These satellites monitor the earth’s atmosphere over the entire United States in addition to adjacent land and water masses.

NOAA – National Oceanic and Atmospheric Administration. A branch of the U.S. Department of Commerce, NOAA is the parent organization of the National Weather Service.

NOAA Weather Radio – Continuous 24-hour-a-day VHF broadcasts of weather observations and forecasts directly from National Weather Service offices. A special tone activates an alarm on certain receivers when watches or warnings are issued. With some radios, this alarm can be tailored to sound for specific warnings affecting counties of your choice. Consult your local electronics retailers for more information.

NWS – National Weather Service. Agency of NOAA responsible for providing weather services to the nation. The mission of the NWS, in part, is "to provide weather and flood warnings, public forecasts and advisories for all the United States, its territories, adjacent waters and ocean areas, primarily for the protection of life and property." This mission is carried out by a network of weather offices located throughout the Unites States and its territories along with a highly trained workforce. Through this network, the NWS provides an invaluable service to government agencies, emergency managers, the media, and the general public 24 hours a day.

Severe Thunderstorm Watch – Issued by the SPC when conditions are favorable for severe thunderstorms in and close to the watch area. A watch is generally outlined by a parallelogram and is usually valid for a period of 4 to 7 hours. A severe thunderstorm is defined by wind gusts of 58 mph (50 knots) or greater, ¾" diameter hail or larger, a tornado, or any combination thereof.

Severe Thunderstorm Warning – Issued by the local NWS office when a severe thunderstorm is indicated by radar or reported by trained observers. A warning may cover a part of a county or several counties and is normally valid for 30 minutes to 1 hour in duration. A severe thunderstorm is defined by wind gusts of 58 mph (50 knots) or greater, ¾" diameter hail or larger, a tornado, or any combination thereof.

SKYWARN – A dedicated team of official NWS-trained storm spotters who devote their time and effort to aiding the NWS mission of savings lives via timely warning services. Essential to the warning process, these observers work in conjunction with local emergency officials to relay timely reports of severe weather and tornadoes to local NWS forecast offices. SKYWARN spotters who are licensed in amateur radio operations ("ham" operators) are especially valuable since they bring an alternative means of rapid communication to the warning process.

SPC – Storm Prediction Center . Situated in Norman, Oklahoma, this office is responsible for monitoring and forecasting severe convective weather, as well as winter weather, in the contiguous United States. This includes the issuance of Tornado and Severe Thunderstorm Watches and various outlooks to highlight the degree of severe weather threat.

Surface observations – Information, including such variables as sky condition, present weather, visibility, temperature, humidity, wind, and barometric pressure, analyzed on a map to determine the various weather phenomena occurring at the earth’s surface. An integral part of the NWS surface observing program is ASOS, which stands for the Automated Surface Observing System. There are nearly 1000 ASOS units primarily co-located with airports across the United States.

Tornado Watch – Issued by the SPC when conditions are favorable for tornadoes and severe thunderstorms in and close to the watch area. A watch is generally outlined by a parallelogram and is usually valid for a period of 4 to 7 hours. A tornado is defined as a violently rotating column of air usually extending from the base of a cumulonimbus cloud and in contact with the ground. A condensation funnel cloud need not be present, but flying debris near the ground should mark the tornado’s lower circulation.

Tornado Warning – Issued by the local NWS office when a tornado is indicated by radar or reported by trained observers. A warning may cover a part of a county or several counties and is normally valid for 30 minutes to 1 hour in duration. A tornado is defined as a violently rotating column of air usually extending from the base of a cumulonimbus cloud and in contact with the ground. A condensation funnel cloud need not be present, but flying debris near the ground should mark the tornado’s lower circulation.

Upper-air data – Information, including such variables as temperature, humidity, and wind, analyzed to determine the weather phenomena occurring in that part of the atmosphere above the earth’s surface.

WarnGen – Warning software accompanying AWIPS and used by local NWS offices to issue warnings and statements of inclement weather.

WFO – Weather Forecast Office. Designation of local NWS operational offices, each with its own area of forecast and warning responsibility. For example, WFO Huntsville (the NWS office in Huntsville, Alabama) issues forecasts and warnings for a 14 county area, comprising portions of southern middle Tennessee and north Alabama.

WSR-88D – Weather Surveillance Doppler Radar (1988). Whereas conventional radar only detects areas of precipitation, Doppler radar also determines whether atmospheric motion is toward or away from the radar and is useful in detecting rotation within a thunderstorm. To date, 123 systems have been installed at Weather Forecast Offices with about 40 additional systems at Department of Defense (Air Force) and Department of Transportation (FAA) sites.