Radars: One Big Supercell in Plains Last Night

That was one big supercell thunderstorm that tracked through southern South Dakota and northern Nebraska Monday evening... strong enough to have an obvious "hook echo" on AccuWeather.com MapSpace™, which doesn't usually show hook echoes due to averaging of data for safety purposes (we don't want people driving into a hook echo because it looks like a rain-free area):

At one point the single storm was responsible for four, count 'em *4* tornadic signatures showing in the NEXRAD data on AccuWeather.com RadarPlus!

(As Rob Dale pointed out, it's important to note that a TVS doesn't always mean a tornado has been detected, it's just the radar's guess at whether or not the potential for a tornado (i.e. 3-d shear vertically) is present).

And the velocity couplets? Don't get me started! Huge inbound & outbound velocities showing strong rotation. At one point the cell even "wrapped into itself" like the Greensburg Tornado (see "Categories" at right).

You can download* radar movies from RadarPlus here. Needless to say, the storm left a trail of tornado reports - fortunately not through any populated areas.

*As pointed out by my detractors, the "TVS" signatures which guess at tornadIC (not tornadO, Rob) conditions sometimes get confused, but I'd argue in this case it was because the storm was so large and severe that the algorithms were confused.