Quincy

Today has two areas of interest, in my opinion. Iowa/northern Illinois: Assuming the early day MCS does not overly disrupt the environment, you should see modest to moderate instability develop by mid-afternoon. Wind profiles look very favorable for supercells. Any storms that can interact favorably with the warm front/convectively reinforced boundary, will have the highest (relatively) tornado potential. West Texas toward the caprock/southeastern Texas panhandle: Wind profiles are not great right now, but there's a weak boundary in place along a SW-NE axis between Amarillo and Lubbock. This should be the focus for storm initiation later today. Although the orientation is roughly parallel to the deep shear vectors, most guidance increases the low-level jet this evening, supporting fairly rapid enlargement of hodographs right around or shortly after 00z. It might be too little too late as storm modes could be messy by then, but I'd suspect there will be at least a couple of tornadoes in this area. In between these two areas, storms are probable over a wide swath from Kansas/Oklahoma to Missouri. The main threat will probably be flash flooding in this region.

It may be a bit elevated, but still that's pretty impressive that it's been more or less maintaining intensity for so long.

I haven't looked super closely at later today, but just glancing at data in more depth now - there will probably be several more tornadoes and a swath of heavy rain across KS/OK again. Thankfully it's a bit farther west than the areas hit hardest on Wednesday/Wednesday night, but still... Wind profiles are impressive for so far south this late in the season, but SW/SSW upper level flow suggests there may be some veer-back signatures aloft. Convective mode should be mixed and most guidance initiates convection relatively early, later this morning. As convective advects north and east, you'll probably see renewed development by early to mid-afternoon across the panhandles and western Oklahoma.

I eluded to this yesterday about the 5/9/03 analog, which was a pretty close match. It's a fine line and if mid-level temperatures were just a touch warmer today, but might not see anything on radar at all south of I-40. Obviously, that's not the case.

The 20z OUN sounding, when compared to other area soundings/observations, suggests the cap has mostly eroded across the OKC metro area. Low-level wind shear is not overly favorable in the area yet, but it should gradually improve with time.

The low-level shear is not very favorable in the SW portion of the watch. Seems odd, but maybe it was a CYA decision for that cell going up. Regardless, the environment becomes increasingly favorable for significant severe with northeastward extent, especially from OKC metro and points northeast.

A bit surprised with "several strong tornadoes likely," but there are some key ingredients that are in better alignment than Monday. The best convergence/forcing appears to be north of OKC along the moisture gradient and that's where models just about unanimously agree on convective development later. I'm not quite sure why this watch is displaced to the south, but maybe they are considering a different watch for up north.

With that said, convective initiation is underway just northwest of Wichita Falls, of all places. Mesoanalysis shows an area of locally steeper low-level lapse rates there. We'll have to see the convection evolves and if it can sustain itself.

Such a delicate setup. The 18z OUN surprised me a bit with so much warming at 700mb. An increase from 5.2C at 12z to 9.0C at 18z. Notice warm layers between 800-650mb. The model solutions with widespread/robust convection near and south of OKC metro seem overdone. This combined with the latest HRRR run implies any storm coverage will be very isolated, particularly near and southeast of a Oklahoma City to Joplin line, or roughly I-44. Any storm that does fire will likely become severe, rapidly, with a high probability of producing very large hail and tornadoes.

I'm not sure exactly how long a launch takes, but I'm willing to bet it's probably an hour or shorter. If you assume the mean wind field is 50 knots, which is roughly what today's is between 850-300mb over central Oklahoma, then you would expect the balloon to travel no more than about 50 miles. Sure, that can change if there are stronger wind fields, but I doubt there are many times in which the mean wind field sfc-100mb wind field is >100 knots. I don't have science to back it up, but most data is probably collected within 100 miles of the launch. It's probably much closer than that, in most cases.

More ominous than Monday given such a clear boundary for storm initiation and better low-level thermodynamic profiles. I don't feel good about today, even if it's just flooding, but with the heightened severe risk as well, just, bleh.

WPC just upgraded the NE OK/SE KS/SW MO area to MDT risk for excessive rainfall.

This. Look at 700mb temperature trends via HRRR/RAP. Rising temperatures south of roughly I-40 and fairly steady near I-44, although there's an area of subtly falling 700mb temps northwest of Tulsa, lining up closely to the ENH risk area. Convective evolution is still a bit unclear. Models, including the HRRR, look a bit blobby, which is better than seeing it show one or two monster cells. With that said, given rising heights and mid-level temperatures that may be fairly steady too, part of me wonders if convection may be somewhat more sparse than modeled, especially near and just southeast of I-44. I hope not, but if it were, that would even more strongly favor intense supercell development with any convection that does initiate. I don't think deep convection is all that likely once you get to areas south of OKC, given warming temperatures aloft.

I really don't feel good about today for a variety of reasons. Ongoing flooding. More heavy rain in flooded areas, with storms likely training over an area near or just north of I-44 in northeastern Oklahoma. Potentially discrete/semi-discrete storms in a highly sheared/strongly unstable environment. With many roads closed, that creates many complicating issues for evacuating, emergency responders and, of course, anyone storm chasing. Since it's in Oklahoma, you know there will be droves out. I just hope people stays safe.

Broyles (and Wendt) jumped from MRGL to ENH with a 10% sig tor delineation from northeastern Oklahoma into southeastern Kansas for the new Day 1. I can't say I disagree all that much. The Day 2 also has 10% hatched tor probs, but for areas a bit farther west.

I haven't looked too closely at tomorrow yet, in terms of forcing or other negatievs, but despite rising heights (which did happen on 5/25/16, for the record), virtually all models show convection by early to mid afternoon. This includes global models, CAMs and HREF suite. Given the background environment, you'd probably expect at least an upgrade to SLGT with the upcoming Day 1 outlook.

Agree with the prospects for a squall line with embedded tornadoes tomorrow. There could be a few left-moving, transient supercells in the Kansas vicinity around the upper level low, but it doesn't look like either area is worth a drive for chasing prospects. It looks like any more substantial Plains severe threats this week may not be until Thursday, although it is possible that a few widely isolated storms might initiate on Wednesday.

Mesoanalysis shows S/SSE flow at 700mb in the area, but it veers to SW just to the west.

It looks like the HRRR may have overcompensated a bit with trending north with the warm front. If one adjusts a bit south based on trends/radar imagery, it would bring the warm front to roughly or perhaps just north of I-40. It does depend on how far south early day convection extends, meaning if any surging outflow shunts northward lift of the front. With that said, with such an anomalously strong daytime low-level jet, one has to wonder of the warm front would not keep lifting north for a bit. I do think that the HRRR might be a bit overdone with discrete convection north of I-40 from the eastern Texas panhandle into western Oklahoma, as a result, but we'll see. Anyway, the 12z MAF/Midland, TX sounding is very telling. The fact that we have a volatile, high-end severe environment already in place at 7 in the morning and this far west, should be alarming. The environment near MAF will advect northeast through the day with the greatest parameter space likely from the Caprock region and Northwest Texas into southwestern Oklahoma.

It's also the max of where the parameters overlap (larger 0-1km SRH north/larger buoyancy south). That's why SPC SREF tornado ingredients/probability has been 75-90% in that same part of southwestern Oklahoma. The bullseye isn't always where the most storms verify.

Well, I'm not able to pull sounding data from the HRRR right now (server issue I think), but by 18hr with the 01z run, which lines up with the longer 00z run, there's upwards of 5000 J/kg SBCAPE with negligible convective inhibition in the DFW area. While forcing is weak/nebulous, anything that can initiate in North Texas given the thermodynamic/kinematic fields, would, at least conditionally, have the potential to become supercellular with a tornado threat.

That 12z MAF sounding is going to be a sharp indicator of how quickly things could start firing in the morning, assuming it does sample on the east side of the dryline. Data suggests there may not be much convective inhibition remaining with strong instability already in place, which is pretty unusual for a 12z sounding that far west. Downstream sounding from DRT shows a 69F dew-point as of 00z. While that's not extreme high-end given SPC sounding climo, the 80F dew-point at CRP is close to a record. In fact, it's pretty rare in any month of the year for an 80F dew-point there, as sounding climo records show the all-time record of 83F. That was in September, either associated with a tropical system or return flow off of the Gulf, which reaches peak temperature around that time. Here is a surface map I put together, highlighting potential tornado threat areas, based on the 00z HRRR. The 00z 3km NAM is not far off and it shows hints of at least semi-discrete convection near/south of I-40 in Oklahoma during the afternoon/early evening. Local climatology suggests backing of low-level flow in central/northern Arkansas given the warm frontal placement tomorrow would support an "enhanced" tornado threat there as well.

Ah, yes. Flooding is another major and perhaps more widespread concern with this system, especially from central/northern Oklahoma into parts of Kansas. Not only is Southern California getting an unusual amount of rain this year, but it’s been very wet in the Plains too. (The whole country for that matter as drought areas have been dwindling)

The HRRR, in general, is good with convective evolution and is more conservative with moisture return than the 3km NAM. That’s why I’d take the dew-point progs seriously. They’re fairly close to what the NAM shows. However, this is a complex, multi-round setup. If morning convection evolves differently than progged, that would change how the rest of the day transpires, especially across the northern part of the risk area. If the HRRR remains consistent and shows a similar evolution with 00z and subsequent model runs, then confidence will be very high. If the model waffles back and forth, that will speak to the complexity even more. As with any convection allowing model, obs and trends will be of the utmost importance. Even if you dial back the HRRR some, it still looks like a tornado outbreak with multiple significant tornadoes is just about unavoidable at this point. There still is a scenario where convective evolution stays messy near/north of I-40, but that’s the best case at this point and probably wouldn’t spare West/Northwest Texas to southwestern Oklahoma.

Based on the HRRR: It starts with West Texas already seeing 3000-4000+ J/kg SBCAPE with minimal CINH by 14z. The low-level jet remains stout, averaging 30-50 knots at 850mb throughout the entire day across the moderate risk area and most of the state of Oklahoma. The shear across Oklahoma would support intense to violent tornadoes, IF storm modes are at least semi-discrete. We’re talking about upwards of 50 knots of 0-1km shear by early afternoon. The parameter space moves into a nearly unprecedented categories over west/northwest Texas in the afternoon with 4000-5000+ CAPEs with increasingly intense wind profiles. Dew-points of 70 degrees up to I-40, even in the eastern Texas panhandle? The HRRR is ominous looking and even if there is some convective contamination, you won’t need much recovery/instability to see numerous intense supercells. The instability advertised on the High Plains given the expected wind profiles is extreme and could very well lead to 4”+ hail reports.