The 2009 Wethersfield tornado and 2006 Greenwich tornado were both rated F1/EF1 in Connecticut but had dramatically different looks on radar.
The 2009 Wethersfield tornado was, by far, a more impressive storm as a whole. Here is a cross section when the main portion of the storm was lashing West Hartford and Newington (with golf ball size hail and 55 knot wind gusts).
Whoa! Now is that a classic looking storm or what!? The overshooting top reached 50,000 ft AGL with an impressive and tilted updraft. The 70 dbz level tickles 30,000 ft. Hail, hail, hail!! I did jump in the car to punch the core of this bad boy… best storm I’ve ever seen!
While there was a strong mesocyclone in the mid levels of this supercell (there’s gotta be something to produce that strong of an updraft/hail core) there was little rotation evident near the ground.
Blah. Sort of lame looking, right? While the storm had impressive mid level rotation there was not much here (OKX 0.5º SRV) around 4,700 feet AGL. That said, the radar is sampling the storm nearly a mile above the ground. We don’t really know what’s happening around 1,000 or 2,000 ft AGL.
On the base reflectivity 0.5º OKX image the supercell is clearly dropping big hail over Newington and West Hartford (along with strong winds) and you can see the beginning of a hook echo trying to form over Newington? This may be a sign of the rear flank downdraft organizing which probably helped along tornadogenesis in Wethersfield. Not surprisingly, given the unimpressive low level radar look, the tornado was short lived.
3 years prior the Greenwich supercell that dropped a tornado in Westchester County first was nearly opposite the Wethersfield case. The Greenwich storm showed decent low level rotation on radar but unimpressive mid level rotation. It was an ugly looking storm.
Pretty hideous, right? Just looking at this 0.5º base reflectivity slice (and let me tell you that other slices are just as ugly) you wouldn’t expect a tornado, right? An F2? No way. But…. wait for it….
Don’t you love Doppler Radar? Classic tornado vortex signature with a tornado ripping across the Tappan Zee stengthening to F2 in Westchester.
The moral of the story here is that most of our tornadoes don’t look as classic as last year’s Hampden County storm. Many tornadoes originate just north of the apex of bow echoes (see last year’s Woodbury tornado), some are weak spinups near the RFD of a powerful supercell (Wethersfield), while others are like the Westchester/Greenwich storm form in relatively unimpressive storms with sizable low level rotation.
Doppler radar makes warning some storms easy – like the Greenwich and Westchester tornado. The Woodbury tornado was a bit tougher to find while the Wethersfield case shows that sometimes doppler radar can miss (especially when our radars are located in Massachusetts and New York!).