The unsettled weather pattern developing this weekend will bring thunder and even the chance of severe weather to parts of the Tri-State. High temperatures will drop back into the mid 50s on Saturday and sink into the mid 40's on Sunday before we shoot back up into the 60' on Monday. A cold front will become stationary along the Ohio River, and will provide a boundary for the smaller storm systems to follow.
Here is a look at the SPC severe outlook for Friday night through early Saturday morning. Cold air aloft and stronger winds will allow elevated thunderstorms to develop that may drop near-severe (smaller than 1") hail over the northeastern corner of the Tristate in Dubois, Martin and Daviess counties in Indiana. "See Text" means you need to read the text below the image, but I've summarized the important parts for you.
By late Sunday, winds will shift to the south again and provide a punch of moisture and energy that will fuel more scattered thunderstorms. Again, the SPC outlook for Sunday is not indicating severe storms, although a few may produce near-severe hail. Time frame is Sunday late afternoon and evening. The green shaded areas show where thunderstorms will be possible. Although no widespread severe weather is forecast, some storms may briefly produce gusty winds and small hail.
On Monday, the upper level jetstream will nose into western and central Kentucky. Energy rounding the base of the trough (the bottom of the kink in the jetstream) will be sufficient for severe thunderstorms, mainly to the southeast of the Tri-State. We'll have to keep an eye on this, because any change in the jet or the track of the low could send the threat closer to us or push it farther south. The SPC has a Day 4 (D4) outlook for severe weather over the Tennessee Valley all the way up into central Kentucky.
The Friday-to-Friday rainfall forecast is still kicking out a couple of inches of rain, concentrated along the Ohio River valley over the next 7 days.
We're already at a 2-inch rainfall surplus for the year, so if this forecast pans out, we'll continue to replenish rainfall we didn't get during the drought of 2012. I'm not expecting any widespread flooding, but if showers and storms train along the stalled front, we could see some localized heavy rainfall and flooding.