The news on Monday, May 20, 2013 was dominated by pictures and videos of the massive EF-5 tornado that demolished a large part of the community of Moore, Oklahoma, causing several tragic deaths and extensive damage. This storm resulted from a relatively common springtime weather pattern, where hot air meets humid air and creates a perfect environment for the growth of supercell thunderstorms and tornadoes over the Great Plains states.
In fact, a low pressure system over Dakotas was the cause of the circulation pattern that created the conditions for the Oklahoma thunderstorms (Figure 1). The far southern zone of the cyclonic circulation around the low pressure area extended south from Colorado and Kansas, pushing and converging extremely warm air at the surface over Texas. Infrared brightness temperatures (Tb) measured by the Atmospheric Infrared Sounder (AIRS) in that region were in excess of 320 K (red). Warm, humid air flowing from the Gulf of Mexico provided the moisture source for the storms as these two air masses converged.
Over the tops of the clouds in the tornadic storm, AIRS shows Tb cooler than 210 K (violet), which is indicative of extremely strong convection overshooting the tropopause altitude of 15 km.
The evolution of the entire event can be seen in fine spatio-temporal detail in Figure 2.
Figure 1. AIRS brightness temperature (Tb) calculated from calibrated infrared radiances (11 um channel) data show the weather dynamics that created the massive and deadly Moore, Oklahoma tornado on May 20, 2013. Explosive storms resulted when low pressure circulation over the Dakotas converged hot (red) air from Texas, humid air from the Gulf of Mexico, and colder air from the north. Cloud top temperatures (violet) indicate extremely strong convection, reaching above 15 km, in the storm itself. AIRS collected these data at 2:40 pm local time. Full-size PNG version. KMZ version (GoogleEarth).
Figure 2. Frame from animation of Global-merged Full Resolution IR Brightness Temperature Data from geostationary satellites GOES-8/10, METEOSAT-7/5 and GMS, for May 19-20, 2013. The time shown is 15:00 (3:00 PM CDT) local time for Oklahoma. The small black '+' symbol shows the location of Moore, Oklahoma. (GOES: Geostationary Operational Environmental Satellite. GMS: Geostationary Meteorological Satellite (Japan). METEOSATs are geostationary meteorological satellites operated by the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT). )
Click on the image to view the animation.
Although these data can be acquired via different routes, the best way is to use the Mirador search engine:
+ Acquire AIRS calibrated radiances
+ Acquire Merged IR
Merged IR data is produced by The Climate Prediction Center/National Center for Environmental Prediction (NCEP)/National Weather Service (NWS).
AIRS is managed by NASA's Jet Propulsion Laboratory (JPL), Pasadena, California, under contract to NASA. JPL is a division of the California Institute of Technology in Pasadena.
Articles about AIRS Version 6 data at the NASA GES DISC: