Yellow area: Slight risk of severe thunderstorms. Green area: Non-severe thunderstorms.

There is a slight risk of severe thunderstorms again today in most of Indiana and pretty much all of Ohio, according to the Day 1 Convective Outlook that the National Weather Service Storm Prediction Center issue at 8:52 a.m. EDT. The slight risk area includes All of Allen County and most of its surrounding counties. It includes all of the Indiana and Ohio counties in IMO SKYWARN quadrant two.

Within the slight risk area, in Adams, Wells, Blackford, Jay, Van Wert, Putnam and Allen (Ohio) Counties, there is a 30 percent probability of damaging thunderstorm winds or wind gusts of 50 knots (58 mph) or higher within 25 miles of a point. Elsewhere in the slight risk area, that probability is 15 percent.

Throughout the slight risk area, there is a 15 percent probability of one inch diameter hail or larger and a two percent probability of a tornado within 25 miles of a point.

Now, a bit of meteorology. Here’s why the SPC thinks severe weather is possible: A surface cold front, stretching from northern Missouri to Northwestern lower Michigan as of 8 a.m. EDT, will progress southeastward across Missouri, Illinois, Indiana and lower Michigan today. A moist air mass is in place in advance of the cold front. The rich moisture will combine with daytime heating to rather quickly make thunderstorm development possible today ahead of the cold front. Ongoing thunderstorms across western and northern Illinois will likely expand eastward in coverage and intensify by midday and/or early afternoon along and immediately ahead of the front. Atmospheric conditions — especially high instability (mixed layer convective available potential energy of 3,000 joules per kilogram) and strong changes in wind speed and direction with altitude will support organized multi-cell clusters and/or line segments, and potentially some supercell structures. Damaging winds and some large hail will be the primary severe storm risks during the afternoon.

Stay alert today for possible severe thunderstorm watches and warnings in the slight risk area.