The NOAA reports that the temperatures wasn’t just record-breaking in March, but beat the prior record by a stunning 8.6°F above the average for the 20th century. In the history of U.S. weather record keeping, only one month has ever seen a larger departure from the historical average: January 2006.
Tornadogenesis—the formation of tornadoes—remains a topic of active research as there is relatively little direct experimental data, owing to the difficulty of prediction as well as measurement. Initially, a variation of wind speed at different altitudes in the atmosphere causes shearing, which can lead to the formation of a horizontal column of rotating air—a vortex line similar to a roll cloud. Beneath a developing storm, the updraft of warm local air can pull this vortex line upwards, creating vertical rotation in the cloud, thereby birthing a supercell. Supercells do not always spawn tornadoes, and the exact causes that result in tornadic or nontornadic supercells are not fully understood. However, the formation of tornadoes within the supercell seems dependent on the downdraft of cool air within the storm as well as stretching of the vortex line, which increases its rate of rotation. For more information, check out this explanatory video and some of the talks by Paul Markowski. (Thanks to mindscrib, aggieastronaut and others for their submissions related to this topic! Photo credits: P. Markowski and D. Zaras)
My dashboard has a whole new flavor now that I got my astrophysicist friend to join Tumblr.