Thanks largely to warm, steamy air, there will be an elevated risk for flooding and flash flooding in the Tri-State Thursday and Thursday night.
First, most of the Tri-State is in a Flash Flood Watch from 4am Thursday through 4am Friday for the potential of heavy rain leading to flooding:
How much rain will it take to get a Flash Flood Warning? Here’s 1 hour flash flood guidance:
Here’s 3 hour flash flood guidance:
6, 12, and 24 flash flood guidance is not worth showing. The summary here is that it must rain quickly and heavily to get flash flooding. Thunderstorms will be needed to get flash flooding tomorrow. 1.5″ of rain per hour will likely trigger warnings.
There is also a slight risk for severe storms over most of the Tri-State tomorrow:
As I see it, there is a lot of instability to fuel storms, but other ingredients for severe storms are surprisingly absent. Here are my forecast severe weather impacts for Thursday:
Notice the most likely time for severe storms Thursday centers between 3pm and 8pm.
As of 3pm, it’s warm outside:
It’s also disgustingly humid outside, with dewpoints well into the 70s:
This means heat indices are over 90° for many:
There are showers and storms developing over central Indiana at this time:
Current thinking is as isolated showers and storms will brush into communities northwest of Cincinnati early this evening before the sky becomes mostly clear tonight:
After isolated showers and storms in the morning, showers and storms will develop and increase in coverage Thursday afternoon:
Showers and storms will diminish Thursday evening. They will be isolated overnight Thursday night and scattered Friday. The weekend will be quiet and peaceful but also humid. More heat is coming next week:
Be alert for heavy rain and strong to severe storms Thursday, especially during the afternoon and evening!