Interesting forecasting process here: the SPC (Storm Prediction Center) issued a Severe Thunderstorm Watch (#301) this afternoon for parts of Illinois and Indiana (no news there, it’s June in the Midwest, afterall). But then, 4 hours later, with a nice bow echo (that radar image will ony be available for 5 or 6 days, sorry) approaching the edge of that watch area, it become a matter of some discussion whether to issue a new watch to the east of the current one (BTW, one reason I find this whole thing interesting is because my county is JUST to the east of Watch 301 as defined at 2pm EDT by the SPC, and this was making me sad since I like severe weather and being inside severe watches). Point in favor of a new watch included, well, the GIANT BOW ECHO of severe thunderstorms, but points against it included, well, a fairly stable atmosphere (e.g. not friendly to the creation or continuation of severe weather) over Ohio.
The solution to the problem of Giant Bow Echo Of Severe Thunderstorms Leaving Watch Area But Will Lose It’s Severe Status About An Hour Later? Extend the current watch slightly to the east. This avoids the issue of issuing a new watch that only includes a few counties and only runs a few hours, but it also makes sure to get the word out to the people of the 7 counties added to the watch area that a GIANT SEVERE (and tornadic, judging by the warnings) BOW ECHO is coming.
Nice. Well played SPC, well played.
/geeking