Thunderstorms Straight Out of Summer

The current SPC Lifted Indices or LI's are at -9 right now across parts of western and central Kentucky with a couple of -10's showing up in far western KY. That, my friends, is some seriously unstable air.

Often in the summer, the air mass may be extremely juiced up, rich with a lot of moisture up above and at the surface. However, the dreaded capping inversion normally does not allow for storm development. But, according to how I'm reading the charts, the cap in not in place.

And it feels like summer out there. Mid 60's dewpoints are making matters uncomfortable at least for me. PWATS, or precipitable water, a measure of how much moisture is in the troposphere, can be labeled efficient rain producers when pwats are above 1.5.

Also, high CAPE values and high PWATS generally are a good sign of intense lightning producing storms.

Therefore, with grounds not able to absorb any more water, expect flash flooding to occur with only 1" amounts with the heavier storms. Also, expect more issues with cloud-to-ground lightning strikes that may affect homes and businesses and the threat of fires.

Finally, if the air column to the troposphere from the surface is saturated, wind gusts would not be an issue. But, mid-level lapse rates look rather impressive which tells me that some dry air may be just the impetus for some isolated strong winds to mix down to the surface with the heavier rains, generally 30-50 mph. But some winds may take on the microburst feature which can spread winds out and gust over 50 mph in some instances.

MS