A fleet of VORTEX2 vehicles tracked a supercell thunderstorm near Dumas, Texas on May 18, 2010.
The storm hunters were able to study more than 20 tornadoes and gather more information on these storms than ever before, said team member Joshua Wurman of the Center for Severe Weather Research in Boulder, Colo.
The blue-green color in the cloud is associated with large hail.
The National Severe Storms Laboratory's field command unit is used to organize and communicate storm activities in real-time. Weather observations from other mobile instruments, mobile radar data, and location information are broadcast over a mobile digital radio network to the field coordinator, who analyzes the information and directs team members to ideal field positions.
A short-lived tornado developed northwest of Amarillo, Texas, on May 18, 2010.
The average tornado warning is sounded 13 minutes before touchdown. Because the warnings don't provide much time, residents in the path of a tornado are advised against evacuating and urged to seek low-lying ground. If warning times could be improved to 40 minutes, Wurman said, residents could make better choices about the risk.
Six vehicles had 45 seconds to drive into the storm, drop data-gathering "tornado pods" and get out of the tornado's path. The timing was critical, and panic was the enemy. Drop the pods too soon and the storm might die out before reaching the instruments. Drop them too late and face 100 mph (160 kph) winds and softball-size hail that can smash windshields.
Tornado PODS are a 3.3-foot- (1-meter-) tall tower of instruments with a flat base to measure wind velocity and direction at ground level, ideally in the core flow of the tornado.
The X-Pol Mobile radar uses a 1.2 inch (3 cm) wavelength to detect small particles including cloud droplets. This radar can distinguish tornado debris clouds from precipitation.
Softball sized hail smashed a van's windshield during a storm chase.
A so-called wet hook storm, over Stinnett, Texas.
Supercell storms, the severe and long-lived thunderstorms that give birth to the most destructive and deadly tornadoes, can spawn tornadoes within minutes. But this happens in only a small fraction of supercell storms, and standard observing networks and radars often fail to capture the atmospheric conditions that lead to a tornado.
The findings from VORTEX2 are leading to a greater understanding of tornadoes, and scientists expect they will ultimately improve tornado warnings and short-term severe weather forecasts.