T-Storm and Tornado Warnings, But No Lightning

Like I noted yesterday, a lot of Severe Thunderstorm Warnings, and even Tornado Warnings are being issued without lightning. If you look at the map below, all the lightning is back in Central Illinois while the warnings are in eastern Kentucky and Tennessee. UPDATE: I have updated the image below to show a little lightning starting up in east-central TN - the previous image (showing zero lightning in KY/TN) is available here.

The reason for this is that there just isn't enough warm air this time of year to generate clouds with high tops. Without high-topped clouds, you can't get the temperature differential for lightning to form (see my previous Lightning Seminar Notes - search for "Lightning Seminar" at right).