andyhb

Those hodographs blended with stout low level buoyancy are going to be a problem if we get at least transient supercell structures.

Well the 18z HRRR would be a bad scenario for just about all of Chicagoland. Also Boscobel WI tornado from yesterday rated EF3, 150 mph winds.

https://www.facebook.com/1339856211/videos/593029138361331/

Some really rapid motion in this video from Boscobel.

That's a major tornado there east of Boscobel. One of the strongest signatures I've seen this year.

Speaking of La Nina, this is quite the rapid subsurface cooling occurring over the past month or so. Now ahead of last year's pace at this time.

Without further analysis, I'd have to think that the La Nina decaying quite early may have been a factor.

Volvo dealership partly collapsed.

Holy christ.

Supercell coming into the northern Philly burbs as we speak bears close watching given what happened just up the road.

Video of the tornado from Insta. https://www.instagram.com/p/CRXAHXQFPyN/?utm_medium=copy_link

Lol I was about to be like "whaaaaaa". Cedar Rapids might have a problem here shortly with that cell on the southern end.

Big tornado near Stanhope now.

There literally was a spotter confirming it at the time and a TDS showed up the scan after. Now have this.

Pretty sure that's confirmed...

Tornado ongoing west of Lake City, IA, heading towards town.

Tornado watch out for Iowa, 50/20 probs. Edit: 10% tor now in the 20z D1 update.

Differential heating boundary draped north of I-80 in Iowa looks to be the focal point later. Mesoanalysis progs have large 0-3 km CAPE in that zone and there should be a fair amount of near-surface vort with backing surface winds in its vicinity.

Matt Petkovic is a clown, wouldn't trust anything that guy spews.

That is a nasty looking tornado.

Holy smokes. Debris to at least 15k feet.

Friday could have significant potential just looking at the progged wind fields overlapping a wide warm sector (pending Thursday's convection). Pretty classic WNW flow hodographs showing up in forecast soundings. Shortwaves with 70-80 kt 500 mb maxes this time of year don't tend to go quietly.

ND/MT/S SK target looks pretty ripe this afternoon with mid-upper 60s dewpoints near the triple point, an arcing dryline, strong ESE surface flow and SE flow at 850 mb pushing 50 kts. Upscale growth would be the main concern, but I'd imagine there will be at least a couple tornadoes in that area later. Further south, moisture is overperforming the HRRR (no surprise) and there's certainly an opportunity for initiation in WY/NE later as a subtle shortwave ejects from the Rockies, although 700 mb temps are quite warm. Certainly a lower probability threat than further north, but could yield something pretty spectacular if it works out.

Here we go again.