High-res short term models put GIANT KABASH on severe weather

Well, I'm not afraid to admit when I'm wrong. And hey, it looks as though the pros were mighty wrong right along with me. It no longer looks likely that storms will be severe today.

Why? Well, both the NAM and the GFS have lost their collective cookies when it comes to what kind of instability we'll be seeing when compared with calculations based on surface observations, as well as the most accurate short term model - the high-resolution "Rapid Refresh" model. The big reason why is because neither model is accurately portraying the effect that early day convection will have on the surrounding air.

I mentioned in a post the other day that I was sitting on the fence about the whole situation as early day convection tends to stabilize the mixed layer and I wasn't sure if moisture would be able to "recover". I was on the fence until yesterday, when the usually VERY accurate NAM4KM came in with a picture of incredible instability in our state for this time of year, and thunderstorm development as well. This now looks to be on of those rare situations where the model gets it really, really wrong. As compared with surface observations, it really dropped the ball with the soundings it forecast for this point in the day. That means that the rest of its forecast is highly unreliable. On top of that, the HRRR predicts less than half of the instability the NAM forecast to be present - roughly 500-1000j/kg over SE Michigan this evening. This could still drive one or two severe thunderstorms, but the large hail I was predicting yesterday is kaput, and truly I don't know how damaging winds could get going with wind fields as weak as they are.

Just one of those situations where the forecast defies convention once again. Sometimes Mother Nature just doesn't want us to know what she's going to do. After all, it is Michigan!