CheeselandSkies

Found the PDS on the NAM despite that hellacious inversion.

NAM cool bias at play again? Just a real headscratcher how we have some models with hot temps/mixing issues and some with capping issues due to cool temps. It is quite dry at 700mb, though. Although I remember people saying dryness at 700mb was gonna be a problem on the Gilmore City day last April.

I wonder if the HRRR is still having those overmixing issues @andyhb mentioned and if so, at what point it will catch on.

Interesting the HRRR still blows up that monster simulated supercell in IL tomorrow but the environment ahead of it is not really impressive...super mixed and with ho-hum low-level shear. I can't get a good sounding in proximity to it that both has impressive parameters and isn't contaminated. Also interesting that the globals (namely EURO) are more bullish on convection than the CAMs.

@andyhb What do you make of some of these RAP soundings? Parameters are absolutely off the chains but there's that pesky low-level inversion. Just the other day we were talking about temps in the 80s and mixing issues, but a lot of these seem too cool (uppers 60s/low 70s) almost like we're more used to seeing from the NAM?

Yeah, I agree on that.

That was initial thinking but now looking like the trough is ejecting more slowly.

With the Day 3 update I'm wondering now if Tuesday's initiation (if any) will be too far west for me to chase, even though it should be quite a bit later than last Friday's. Not really keen on a west of I-35 target after working 3AM-noon. Was one of the things that made Friday a no-brainer go for me.

I think the main things that's' not always conveyed is that oftentimes the sparser the storm coverage, the more dangerous the hazards can be from any one storm. Meteorologists & chasers know it, but EMs and the general public usually do not.

Yeah, I only found out about that when I was looking through the Wikipedia tornado list last night (still waiting on DVN to officially confirm the handoff near Keota instead of having one EF4 path all the way from Wapello County up to Johnson County, been spamming them on Facebook with me and @hlcater's video). Sounds horrible, but they actually got lucky it wasn't a stronger tornado.

Out now...very interesting and rather ominous wording for both ends of the setup (southern one also upgraded to tornado-driven MDT).

The max I do see is 20...right on the Mississippi near Le Claire, IA.

Holy hell. Nearly 5,000 j/kg of SBCAPE in early April...and nearly 300 j/kg 3CAPE. This is just east of Iowa City. Continues to look highly likely I'll be retracing my steps from Friday.

Good luck & stay safe!

Thing was, this supercell/tornado seemingly did everything within the span of about five minutes. Cycle/twins. Cone. Drillbit. Multiple vortices. Helical vortex. "Ghost train" inflow jet. Massive debris cloud. Wedge. Too fast for me to take it all in, especially what with it being my first real significant tornado intercept.

Thanks, @hlcater. I didn't mean to steal your thunder (pun maybe-intended, lol) by linking your video earlier, but I wasn't sure if you were still an active poster on here. Full version of my video is now up, btw.

Looks fine to me. Any April I'm not in the second-tier or deeper blue is a good one.

The 18Z NAM EHI map almost looks like I imagine it would have for Palm Sunday 1965...large values extending from eastern Iowa across northern Illinois/far southern Wisconsin to northern IN and southwestern Lower MI. They don't extend quite as far east as the major activity did that day, but the overall pattern seems quite similar.

NAM sounding for near Cedar Rapids, still pops a PDS TOR despite being valid for 03Z and with the NAM's (a little more plausible in this case) cooler temperatures. Large 3CAPE again, like yesterday. My one caveat about yesterday was that the forecast hodographs in Iowa seemed to have a lot smaller curvature than I would have liked to see. Glad I didn't let that dissuade me from chasing! That is NOT an issue Tuesday!

Northern Arkansas. Holy hell.

GFS sounding from the IL side of the QCA. After considering retargeting to there yesterday (good thing I didn't), I may end up there on Tuesday.

If this is the current EURO run that Trey posted (and I don't see why it wouldn't be, he seems to be trustworthy in that department), still looks like all systems go for Tuesday. As @andyhb and @largetornado noted above, a carbon copy of yesterday could be the FLOOR with this one. https://twitter.com/ConvChronicles/status/1642202540732305412 As an aside it's annoying that Twitter is still so heavily used among the met community, I've never liked the platform (had an account, deleted it when they eliminated the feature that I found most useful), times 1,000 now that it's Elon Musk's plaything.

@hlcater got it, too. Appears he was a little further south initially so you can see the meso handoff and "twins" better. In real time I'd thought the whirl of debris that abruptly appeared behind the tree line was just the original tornado getting closer and emerging from the rain; not that that murky mass in the background was still the original tornado. There's a reason I don't intend to get super close, lol.

Already took next Wednesday off to keep open the possibility of chasing Tuesday afternoon...even before what I saw yesterday.

Uploaded an unlisted quick cut to my YouTube channel. Now off to bed.