2020-04-07 EVENT: IA/WI/IL/IN/MI

[Nick Dewhirst]

The 18z HRRR is essentially the same as this morning. And there is a bit of support from the NWS. Detroit believes the warm front will win out, bringing temps well into the 60s, nearing 70 generally south of I-96 and west of I-275.

Dews still seem too high, but instability should be sufficient anyways. Definitely a big hail/wind risk with any storm that pops up with an isolated tornado threat near the front.

 

[Bob Hartig]

I'm much more interested than at first, and I agree with you on that assessment. The latest NAM weakens CIN considerably, and other ingredients seem to be in place. Now I'm thinking, What's not to like, and maybe even be concerned about since HRRR wants to bring it right over my area. Maybe I'm guilty of a slight regional bias. (Particularly since my car is out of commission till I get it into the shop Wednesday.) At this point, I'll be watching to see how things shape up throughout the day and, from maybe 21Z on, depending, wishing my car wasn't out of whack.

 

[Nick Dewhirst]

I’m in the exact same boat. I’m considering a chase should a threat evolve locally. I’m just NW of Detroit so it might be dark when storms roll in for me, but something around dusk would be really nice. Reed Timmer has been focusing attention on southern MI all day. The marginal risk really seems too low. At least a slight risk seems warranted.

 

[Nick Dewhirst]

The NAM/HRRR are actually in great agreement now. Both have nearly the exact same parameters in place. Based on where I live, I’m liking this

 

[Jamie G Cox]

I can understand the SPC not wanting to oversell back to back reports in the same region. But they have upgraded to putting me almost right in the middle of the little 5% tornado bubble. Unfortunately it will probably be nighttime, like every other big day is around here lol. I'll definitely stay up for it and keep a close eye on it throughout the day.

Here, about 25 miles northeast of the Michigan/Indiana/Ohio border, it is currently still below 50, rain has mostly passed, still pretty gray but the sun just started trying to come through and the cloud cover isn't as thick.

 

[rdale]

I'm feeling far more optimistic for today than I expected to a few days ago! With all convective models touching something up, and the HRRR still being the HRRR, there isn't much reason to doubt the threat of tornadoes this evening in the southern half of Michigan.

Nearly impossible chasing with storm motion (unless one starts in Grand Rapids and goes down I-96 ) but a worthy event still likely.

 

[Nick Dewhirst]

Per the GOES-16 satellite, clearing is already underway across northern IL/far southern WI/NW Indiana. Albeit there are still some higher level clouds that will move east out of Wisconsin into Lower Michigan, I’d expect most areas along/south of I-96 to have a good period of destabilization today. This will also aid in northward progression of the warm front, which is currently draped NW to SE across northeast IN and central OH.

MLCAPE values of 2000 J/kg should be realized across the slight risk alongside bulk shear of 50-60 kts. That’s a very favorable combo (I don‘t know where to find BRNs forecasted, but they’re probably in the 20s, which is very nice). Very steep mid-level lapse rates of up to -8.5 C/km will produce some very large hailstones, and 0-1 km SRH locally exceeds 200 m2/s2 in some locales in the 5% tornado probs.

Overall I think this threat has substantially increased in the last 18 hours or so, and the SPC is still talking about an upgrade to enhanced (seems likely).

 

[Jamie G Cox]

Right on cue with the SPC, for mostly hail and wind apparently @Nick Dewhirst. Don't get large hail too often around my neck of the woods. Really wish the timing of the event was earlier. It feels like every single high/moderate/enhanced risk in
south central Michigan over the last decade, arrives after dark and fizzles out or becomes a mess by the time it arrives.

 

[Nick Dewhirst]

I think the main thing helping this event is that storms will likely be firing NW of Grand Rapids and getting their strength together as they track southeast. I bet storms will be at peak intensity across far southern Lower Michigan. It‘ll probably transition to mainly wind in Ohio, but the fact that lapse rates are so steep in that EML plume will really aid the hail here. It’s not too often we get an EML this nice in Michigan *with* thunderstorm initiation.

I wouldn’t be surprised to hear of some 3” hailstones in localized spots this evening, along with the straight-line winds and isolated tornadoes.

 

[Jamie G Cox]

Things really cleared up and warmed up fast in Hillsdale County, Michigan. Beautifully sunny and already 66. Looks like the temps are going to be a little higher than forecasted today.

 

[Nick Dewhirst]

I’m up in southern Oakland county. Still mainly cloudy but looks like the sun is knocking on our doorstep. Mid 50s here but mid to upper 60s and a couple 70 degree readings west of me. Looking good tonight.

 

[rdale]

HRRR (and other models - but that was first ) really overdid moisture. Still getting nice cells, but tornado threat really limited as a result.

 

[Nick Dewhirst]

Hail will likely be paramount for this event.

 

[Bobby Little]

pea size hail came down good 1/2 hr at my place..eagle mich. had to move the truck in the barn

 

[Todd Lemery]

Well...Another one bites the dust