They noted very strong outbound velocities right next to very strong inbound velocities in the radar data. In 1973 NOAA meteorologists Rodger Brown, Les Lemon and Don Burgess discovered this information’s predictive power as they analyzed data from a tornado that struck Union City, Okla. This key information allows forecasters to see rotation occurring inside thunderstorms before tornadoes form. The Doppler radar currently used by the National Weather Service also measures the frequency change in returning waves, which provides the direction and speed at which the precipitation is moving. By measuring the strength of the waves that return to the radar and how long the round-trip takes, forecasters can see the location and intensity of precipitation. Radar works by sending out radio waves that reflect off particles in the atmosphere, such as raindrops or ice or even insects and dust. Forsyth, who is chief of the Radar Research and Development division at NOAA’s National Severe Storms Laboratory in Norman, Okla., is most concerned about improving warning times for tornadoes because deadly twisters form quickly and radar is the forecaster’s primary tool for sensing a nascent tornado. Meteorologist doug forsyth is heading up efforts to improve radar, which plays a role in forecasting most weather. If the efforts succeed, a decade from now residents will get an hour’s warning about a severe tornado, for example, giving them plenty of time to absorb the news, gather family and take shelter. Tools for forecasting extreme weather have advanced in recent decades, but researchers and engineers at the National Oceanic and Atmospheric Administration are working to enhance radars, satellites and supercomputers to further lengthen warning times for tornadoes and thunderstorms and to better determine hurricane intensity and forecast floods. The intensity continued early in 2012 on March 2, twisters killed more than 40 people across 11 Midwestern and Southern states. Fourteen extreme weather and climate events in 2011-from the Joplin tornado to hurricane flooding and blizzards-each caused more than $1 billion in damages. April was the busiest month ever recorded, with about 750 tornadoes.Īt 550 fatalities, 2011 was the fourth-deadliest tornado year in U.S. A month earlier a record-breaking swarm of tornadoes devastated parts of the South, killing more than 300 people.
The Joplin tornado was only one of many twister tragedies in the spring of 2011. Although emergency officials were on high alert, many local residents were not. The warnings had come sooner than they typically do, but apparently not soon enough. A tornado watch had been in effect for hours and a severe weather outlook for days.
Nearly 20 minutes before the twister struck on the Sunday evening of May 22, 2011, government forecasters had issued a warning. Winds exceeding 200 miles per hour tear a devastating path three quarters of a mile wide for six miles through the town, destroying schools, a hospital, businesses and homes and claiming roughly 160 lives. Then the blackened sky over Joplin, Mo., releases the tentacles of an enormous, screaming multiple-vortex tornado.
After the deafening roar of a thunderstorm, an eerie silence descends.