Good morning all,
We have a complicated situation unfolding over the next 36 hours. The timing and potential severity of thunderstorms is difficult to get a handle on this morning, but I will try my best to at least set the table for you.
We still have a pretty dry air mass overhead, but moisture is building off to our west. Here’s a look at this morning’s weather map with the dewpoint temperatures: Along the northern fringes of that juicy air mass across the Midwest, thunderstorms will likely get going late today and early tonight.
As the warmer and more humid air pushes east, the air mass across the region will become much more unstable. CAPE (Convective Available Potential Energy), a measure of instability, will get quite high tonight. These values may be overdone, but even if you reduce them by 1/2, they are still quite high. This animation covers 8pm this evening through 8am Wednesday:
With the ingredients for big thunderstorms there, the Storm Prediction Center has placed parts of the region (but NOT the Mahoning Valley) under an enhanced risk (yellow) of severe weather through tonight: Here are the SPC odds of a tornado within 25 miles of any location: Large hail odds: Damaging wind odds:
So, the threat appears to be south and west of Youngstown tonight, right?? PROBABLY, but all of this is subject to change. This is the type of setup that is notorious for producing surprises.
My gut feeling is that we will have TWO windows for heavy storms that could produce severe weather. 1) Very late tonight and early Wednesday. 2) Wednesday late afternoon/early evening. The main threat will be damaging winds. Large hail will be a secondary threat. The tornado threat should be very low.
Check out this animation of the simulated radar product off of the latest hi-res NAM model (covering midnight Wednesday to 8pm Wednesday): This model may have a pretty good idea, or it may be full of it! We should know much more this afternoon and evening. Check out “Weather For Weather Geeks” this afternoon for a full update.