Following a damp start to our Monday, quieter weather has settled into the Ohio Valley, but so too has the high humidity. Thankfully, temperatures didn't climb much higher than the mid 80s for many of us as it was a rain-cooled afternoon across the Tri-State - even then, heat indices soared into the low to mid 90s at times earlier today. It looks as though the remainder of the evening will be mild, muggy and ultimately, quiet. Expect temperatures to dip into the upper 70s by 10PM before only falling as low as 75° by dawn Tuesday. Despite the drier weather during that later half of our Monday, you may want to grab an umbrella on your way out the door, isolated showers may roll back in over some spots tomorrow morning.
Scattered rainfall will linger for some of us though 9AM or 10AM before dissipating and giving way to a drier, yet humid afternoon. Current projections indicate that temperatures will push toward the mid 90s for much of the region tomorrow afternoon; we look like we may hit 93° in Evansville. Worse yet, our saturated atmosphere will make our high in the mid to low 90s feel more like 105° to 108° at times tomorrow afternoon! As a result, the National Weather Service has placed nearly the entire Tri-State under a Heat Advisory from 10AM through 8PM Tuesday. Please do your best to reduce time outdoors tomorrow, especially during those peak heat hours. In fact, the same can be said for Wednesday, Thursday and Friday as heat indices north of 100° are expected for each of those afternoons.
The combination of high heat and oppressive humidity on Tuesday won't only make for a dangerously hot afternoon up and down the Ohio Valley, but it will help produce our next round of potentially Severe storms as well. The latest model data suggests that clusters of shower and thunderstorm activity will begin to form between 2PM and 3PM tomorrow. The clusters, fueled by the excess of heat and humidity at the surface, will gel and intensify though the late afternoon and early evening. It looks as though the last of these storms will exit south of the Tri-State by 10PM. While many of the storms will generate torrential rains and small hail, the greatest threat from Tuesday's storms will be damaging straight-line winds in excess of 60 mph.