Severe Storms Back in the Central U.S. This Weekend

Drought has been the primary weather story across the Midwest since late-summer as a persistently dry pattern has allowed severe drought to develop from across much of the Ohio Valley into the Lower and Middle Mississippi River Valleys. Check out the latest Drought Monitor.

I joked on a social media that "flow season" was returning, but there's a twinge of seriousness to it, even more so now a few days later.

I woke up this morning to the Storm Prediction Center having highlighted a region of severe thunderstorm potential on day 6 (Saturday, Oct 18) in their Days 4-8 outlook. Their discussion mentions the possibility of organized severe storms, including the potential for all severe hazards - damaging wind gusts, large hail, and perhaps tornadoes.

As we move out of local, tough-to-forecast-in-advance, mesoscale-driven severe weather season and into "flow season", what I affectionately refer to as that lovely period from late fall into the spring when we see the jet stream come back to life in the mid-latitudes, bringing storm systems back into the Central U.S. and potential severe weather events that are forecastable at a longer range. During the summer season we're often trying to pick out the location of subtle boundaries from convective events over the previous 12-24 hours as focal points for renewed storm potential. When the jet stream comes back to life, we start to work with bigger storm systems that appear on global models at a longer range, though their inner-workings and the ingredients for organized severe storms still take some time to lock in.

So, just because this Oct 18-19 jet stream wave has been apparent on global models for several days now doesn't mean we've got anything locked in place. What seems reasonable right now is the idea that a big storm could or should exist in the Central U.S. next weekend, but what isn't clear yet is where exactly this area of low pressure will be on Saturday afternoon, and how much moisture it has tugged northward from the Gulf, how much instability will be available, and how shear profiles will stack up across the warm sector.

So for now, let's keep an eye on it! It's been a quiet, dry late-summer and fall and rain is desperately needed in a lot of areas. This storm could deliver a nice dose of moisture, perhaps along with a little bite.