RCNYILWX

I was the NWSChat/Slack person for the event, responsible for all of our main room chats and also a room we set up for city of Chicago support. Easily the most chat posts I've made in an event, just a total barrage at the height of the it. One of our radar operators recommended to post ~10 confirmed tornadoes' on there because that was about right. Almost every circulation had an at least brief TDS. Just hard to describe how crazy it was during that time, including briefly sheltering when we saw power flashes outside our window. Anyone on here who has pertinent damage information and photos for our survey teams tomorrow, please email [email protected]. Also you can let me know in a PM if you're trying to send information to one of our neighboring offices affected tonight. Sent from my SM-G998U using Tapatalk

That was mostly or entirely us because we were only in shelter for a few minutes. Had no choice but to go the carpet bomb route. When the entire line is spinning, go big lol. Sent from my SM-G998U using Tapatalk

NW Indiana would like to have a word with you lol Sent from my SM-G998U using Tapatalk

Nevermind discrete lol, it didn't have to be. Night of the QLCS twisters once the LLJ ramped up and low level shear increased markedly. One of the craziest nights in my now almost 14 years here. Sent from my SM-G998U using Tapatalk

Wonder if there's a play for semi discrete mode for longer this evening. Not like it's unheard of in these setups. And if that were to happen, the forecast soundings are favorable for strong tornadoes. Sent from my SM-G998U using Tapatalk

00z HRRR supports the strong wording in the day 2 update this afternoon.

We (at LOT) strongly suspect the spin-ups to your south and southeast were gustnadoes on the outflow. A suspicious area of the outflow passed right through Hooppole where one of the supposed tornadoes was reported from. Since it's dried out lately, it's likely that the gustnadoes were kicking up a bunch of dust.

I think tomorrow looks like a typical slight risk, unless the MCV is stronger and boosts otherwise middling deep layer shear. That definitely can't be ruled out, and interested to see the 00z guidance trends. I suspect the 18z NAMs slowed too much. Sunday has a pretty high ceiling, including within the LOT CWA. Both NAM runs today were scary bad, but outer ranges of the NAM caveats apply. Even on the Euro solution, the morning convection does limit destabilization and probably the magnitude of the threat farther north, likely not enough to preclude brief tornadoes near the sfc low and warm front, though. Farther south, forecast soundings and hodograph shape support an all hazards threat, including potentially strong tornadoes. Given the dynamics at play and time of year, better air mass recovery farther north and a higher end threat are firmly within the realm of plausibility, considering the northward trend of the surface low track.

Rolling Fork was right there too. Probably even closer than most realize to getting EF-5 ultimately. Sent from my SM-G998U using Tapatalk

The pseudo dryline greatly narrowed the risk zone on this side of the lake. Plus the core of 500 mb cold pool lagged enough to limit lapse rates and destabilization east of the dryline. Only had low-mid 60s temps with near/around 50 Td over northeast IL and far NW IN, which yielded 200-300 j/kg MLCAPE. Needed the 500 mb cold pool to lag less and/or temps around 70 to boost MLCAPE and get it done, as the instability we had wasn't enough to balance out the 40-45 kts of effective bulk shear.

Synoptically it's definitely a good setup. I noticed the more meridional flow pattern aloft resulting in the backing you noted. That looks most problematic over Iowa due to the closed off mid-upper low. There will likely be very good sfc-700 mb veering, which may be enough to get it done despite the backing aloft unless/until things get too messy. Wind profiles are better with south and eastward extent but then the lapse rates are forecast to be pretty weak during the day on Tuesday. Certainly possible the GFS is overdone with elevated convection near and north of the front, but it does make sense conceptually to have some. I think it's pretty likely the warm front will get hung up a bit farther south in the LOT CWA until the late afternoon and evening. Haven't looked at latest guidance today because I'm on midnight shifts. Last night I was most concerned locally about Tuesday night when the lapse rates improve and strong forcing arrives while the stout southerly low level flow does work in offsetting nocturnal stabilization.

When April 2019 started off better, felt optimistic, and then had incessant precip the 2nd half plus of that month including the two big snow events. The genuinely nice Aprils are rare around here, but the truly awful ones like 2014 and 2018 definitely stand out. Sent from my SM-G998U using Tapatalk

Today locally is what every day was like in April 2018. Glad we don't have a cold pattern locking in.

Re. the SPC outlooks yesterday, took a hindsight look at yesterday's 12z HREF plus the Nadocast Twitter feed. A good case can be made that SPC should have issued a 10% hatched tor in the general vicinity of the area affected by strong tornadoes, by the 1630z or 20z update. Plenty of boxes were checked environment wise in the HREF mean fields, plus some of the neighborhood and paintball UH probs. The 24-hour STP based calibrated tornado probs had a spot of 10% right near one of the strong tornado tracks. Since they had a slight with 5% tornado probs, it wasn't an egregiously underdone forecast. 8/24/16 is a much better example of that when doing hindsight assessment of the day's SPC mesoanalysis fields. Sent from my SM-G998U using Tapatalk

NAM'med, as they say. If I had the power to get two changes in NCEP modeling done tomorrow, I'd discontinue the NAM and only have 24 hours of publicly available CAM data (and RAP data).