Quincy

Enhanced Risk issued for a small area in and around Oklahoma City. The more impactful storms (in terms of population impacted) may be - cluster of evening/overnight storms with large hail and damaging winds.

Models have also been trending toward less moisture return. HRRR had lower 60s dews reaching to I-40, while now it has CDS struggling to hold around 60F through CI time. Cloud-cover is finally moving out of the eastern panhandle/western Oklahoma region, at least. It looks like there might just be enough moisture in place by peak heating. Wind profiles stronger favor supercells, so as long as a robust updraft can form, it should go spinning into the night... or aleast for a few hours near/along the Red River.

It’s 1977 all over again

Was it really the cap, or more of a function of less boundary layer heating and poor low-level lapse rates? I know a cap is influenced by boundary layer heating, but the models were way off. 1-2C difference in lapse rates is huge. It’s not like they progged 13C at 800mb and it was 17C. When I think of too much cap, I think of orphan anvils and failed CI. We had plenty of CI today, but I’m guessing bad lapse rates and meager low-level cape led to less intense parcel acceleration. Updrafts weren’t necessarily as intense as many expected. Ever since that busted tornado outbreak “swarm” in Oklahoma, I’ve started taking LLLRs a lot more seriously. There is a strong correlation between higher end tornado episodes and LLLRs. Likewise, a lot of busts have junky low-level thermodynamics.

Storms in NE Oklahoma look weak so far. Lapse rates are still pretty awful.

I haven’t been too impressed by the HRRRv4 this season. Mixed results, but also some bad stuff, like today: It shows substantial 0-3km CAPE where mesoanalysis shows little to none.

Pretty ugly and satellite shows thick cloud deck, particularly across the Missouri side of the 10% hatched.

Just ran back three runs to 15z and HRRR was progging 6.5-7 C/km LLLRs where the 18z run at hour 1 has 5.5 C/km... Definitely trending down, but there still is some time.

As of 18z low-level lapse rates were anemic from far northeastern OK into southwestern MO. There still is some time to heat, so we’ll see...

This. Watch temperature trends closely. HRRR is not far off as of 15z, just 1-2F too cool in parts of central OK. However, it may only take an extra degree or two of heating to break the cap. That’s what we saw happen on 4/28.

Morning storms exiting NE Oklahoma are near an effective warm front. Elevated instability exists to the NE, while most surface-based instability is SW. Note that the 700mb thermal ridge is over western OK at the moment. As it shifts east, storms lift into/through Missouri and capping takes over. Morning storms have little to no impact on mid/late afternoon activity. Unless there’s some outflow boundary... Let’s say that scenario doesn’t reduce the severe threat.

Ran into some large hail producing elevated storms in north-central Kansas this morning.

I don’t really have too much to add. Looks like a one-two punch. Morning/early afternoon hailers from northeastern KS into MO, then watch the front/trough unzip by 21-23z from SW MO into OK. HRRR showed some steep low-level lapse rates, but 0-3km CAPEs may be limited with southwest extent. Biggest question in my mind is storm mode in Oklahoma. CAPE/shear will be there. Deep shear vectors probably favor mixed modes and a few supercells, but how long can storms stay discrete? We’ll see.

A quick and dirty comparison shows some similarities to 4/28 and almost in the same area. There might be slightly longer residence time for discrete storms this go around. Could have another SE to S moving tail end Charlie in the central Oklahoma vicinity. There’s also a signal for morning convective activity, a storm cluster or even an MCS dropping from northern Kansas toward the Ozarks. Wonder if that may shunt the front farther south and/or reintensify across Missouri. Currently wrapping up a chase in Nebraska. I’ll take a closer look in a couple of hours.

After tomorrow, the following seven days look very quiet and generally unfavorable for severe weather across the central states. NW flow can’t get it done this early in the season, as moisture return is usually anemic north of I-40. With that said, it is common for a lull in activity that in early May. We just had the most active April since 2011, so it was bound to quiet down eventually. It’s rare to have an extended period of consistently active severe weather during the first half of spring. Interestingly enough, 2011 has followed a similar tornado curve to this year. Recall that in 2011, after late April, the pattern basically shut down for two weeks. It wasn’t until mid to late May (roughly four relatively quiet weeks) that the pattern became active again.

So much for farther south getting any intense storms... That didn’t happen until after sunset. The triple point and warm front did not disappoint from what I saw. I was able to catch this storm in far eastern Texas before calling it a night:

Mesoanalysis shows some residual capping. Kinda wish FWD had launched a special sounding, but it might have been west of the dryline anyway. It’s going to be a close call down here.

Looks like they’re a little slow to get going, but the environment is becoming increasingly favorable. Low-level winds are backed to southeasterly downstream, although dews are still only in the upper 50s/lower 60s.

Also: the low-level jet looks stronger in NE Texas as well. Confidence increasing that this will be the area to watch.

Based on latest trends from obs and high-res guidance, it looks like moisture return north of the Red River will be marginal at best. Forcing near the triple point should still result in vigorous convection, but I have some doubts about the tornado threat there. I agree that East Texas (especially north) looks better with respect to moisture and instability. I’m in Paris, TX and about to head south. Just came from Hugo, OK and it was overcast and gloomy there. I’m not a fan of the terrain southeast of I-30, so hopefully storms can initiate near or north of there.

Noting some weak convection near the Red River already. Likely elevated. Wonder if that ends up re-enforcing a moisture gradient down there. Could be just enough to stunt moisture return into SE OK a bit, but not totally sure.

Agreed with moisture concerns. Looks like mainly a severe hail threat initially. As the low-level jet strengthens and moisture return increases a bit closer to 00z, still think there is a bonafide tornado threat. Especially if the storm(s) near the triple point ride a pseudo warm front and don’t congeal into a messy blob.

Some shades of two days ago, obviously a bit different synoptically, but there will be a surface low moving east across Oklahoma with CI ahead of a dryline/cold front. Roughly 100 miles farther east. This time, CI seems more probable with southward extent, with more of a linear mode evolving north of the surface low into NE Oklahoma. The thing that jumps out to me the most are lapse rates. They look quite steep from SE Oklahoma into NE Texas. Storms may be more prolific hail producers than Wednesday was. The tornado threat is most apparent near and south of the surface low.

A bit late to the game, but chased the Springer, OK tornado from start to finish today. It lasted close to 10 minutes. It was near a wooded area and I think that’s why we didn’t see a lot of streams or close footage. I had to drive a few miles east before I found an acceptable clearing. There were zero roads going north... Quick note about streaming and bandwidth. I’ve had really bad issues with cell service lately, probably and combination of throttling and heavy usage due to the virus. Anyway, I had a “strong” signal, but had major issues with internet with this storm. Maybe it was all of the chasers around, but it was really frustrating and worse than usual during my chases in Oklahoma.

They outflow boundary from Duncan to Pauls Valley, OK continues to drop south. Temps are averaging near 63F on the immediate cool side. Looks like the focus area is getting more narrowed down to the Red River.