andyhb

Supercell near Marble Rock IA looks prime for a sig tor.

SHIPS Prob RI for 20kt/ 12hr RI threshold= 61% is 12.4 times climatological mean ( 4.9%) SHIPS Prob RI for 25kt/ 24hr RI threshold= 82% is 7.5 times climatological mean (10.9%) SHIPS Prob RI for 30kt/ 24hr RI threshold= 76% is 11.1 times climatological mean ( 6.8%) SHIPS Prob RI for 35kt/ 24hr RI threshold= 70% is 17.9 times climatological mean ( 3.9%) SHIPS Prob RI for 40kt/ 24hr RI threshold= 53% is 22.2 times climatological mean ( 2.4%) SHIPS Prob RI for 45kt/ 36hr RI threshold= 73% is 15.8 times climatological mean ( 4.6%) SHIPS Prob RI for 55kt/ 48hr RI threshold= 47% is 10.0 times climatological mean ( 4.7%) SHIPS Prob RI for 65kt/ 72hr RI threshold= 31% is 5.9 times climatological mean ( 5.3%) SHIPS RI probs are going berserk now, as expected.

Note the center's westward jog as it crosses Cuba.

987 mb on the new advisory.

Detailed surge risk map of New Orleans.

Looks like it will take a track along the length of the loop current rather that perpendicular to it.

Betsy is close to the worst case track, which would be coming from the SE/SSE putting the NW and eastern eyewall over the metro/lake. In such a case, water would be funneled from the Gulf into the lake and then piled into the levees by northerly flow on the lake. The Mississippi would also see a surge.

Here's a link to the folder for the SHIPS text files for those interested. https://ftp.nhc.noaa.gov/atcf/stext/ The ones you'll want to use for this storm are entitled/formatted: "YYMMDDHHAL9921_ships.txt", where YY is year, MM is month, DD is day, and HH is hour of issuance. Probs for 65 kt/72 hr RI for TD9 are already fairly high and I'd imagine they will rise.

Potential Julian sounds like Carla Cradle music to me.

...which is usually pretty good with intensity forecasts...

SHIPS RI probs starting to take off with Grace especially beyond 24 hours. SHIPS Prob RI for 20kt/ 12hr RI threshold= 10% is 2.1 times climatological mean ( 4.9%) SHIPS Prob RI for 25kt/ 24hr RI threshold= 33% is 3.0 times climatological mean (10.9%) SHIPS Prob RI for 30kt/ 24hr RI threshold= 22% is 3.2 times climatological mean ( 6.8%) SHIPS Prob RI for 35kt/ 24hr RI threshold= 11% is 2.9 times climatological mean ( 3.9%) SHIPS Prob RI for 40kt/ 24hr RI threshold= 8% is 3.3 times climatological mean ( 2.4%) SHIPS Prob RI for 45kt/ 36hr RI threshold= 21% is 4.5 times climatological mean ( 4.6%) SHIPS Prob RI for 55kt/ 48hr RI threshold= 27% is 5.8 times climatological mean ( 4.7%) SHIPS Prob RI for 65kt/ 72hr RI threshold= 33% is 6.2 times climatological mean ( 5.3%)

Overmixing.

I'mma guess that's a big time tor.

Wedge tornado reported on the Sycamore cell, heading for Lily Lake.

I mean 81/73 at ORD would suggest they have some time.

Big tor near Sycamore.

Big tornadoes incoming on the Sycamore and Elgin cells most likely. Bad, bad, bad.

Going to have a real problem for Chicagoland over the next few hours. All of these storms have been efficient in producing tornadoes.

Scott Peake is on it.

Given the timing of these things, it looks like they'll approach the metro right at rush hour. Not ideal... There's also one or more boundaries draped across the general area where they'll track.

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.