The Storm Prediction Center has had an area outlooked for a few days now across a broad portion of Oklahoma and Texas. With ample moisture and a strong jet stream overhead, it does appear that any storms that can form will be severe — but at this time the main threats do look to be more of the hail/damaging wind variety.
The surface pattern shows a sagging front and a sharpened dryline just at sunset on Thursday. Some backing winds near the dryline/front intersection are visible in SW Oklahoma/Western North Texas.
A pulled box sounding from the intersection fo the cold front and dryline reveals a pretty poor wind profile overall with some areas of negative SRH in the lowest 3km.
The 850mb winds are displaced east of the dryline on Thursday. This will limit initial storm organization as well as the low-level shear.
The first, and most obvious problem I think, is that models are consistently showing the low-level jet displaced well east of the dryline during the afternoon and evening. This is creating an environment characterized by very elongated hodographs, but very little low-level shear. This can favor supercells — but more often it is a signal of messy storm modes with giant hail being possible.
- The surface pattern shows a southeast sagging cold front across Oklahoma and a diffuse dryline extending south from there across North/Central Texas.
- Models have wanted to speed the cold front passage up on recent runs, which is always something you want to watch for this time of year.
- The front/shear orienation all but guarantees linear storm modes along it.
- Weak to moderate instability will be present by peak heating across the region.
SREF shows a broad area of severe weather risk on Thursday near sunset. Nothing exceptional but it does point to the likelihood of some severe weather.
I think it is pretty obvious this isn’t going to be a robust tornado setup with the data we have in right now. It’s not a situation where you can rule out a tornado or two as-is — but I’d classify it as a very low risk right now.
- This is a case where any tornado risk that does exist will probably be closer to sunset as storms move far enough east that they enter into the stronger wind shear.
- The problem will be, of course, that most storms will be more multicelular or linear given the exceptionally poor wind profiles earlier in the day.
- Another thing that emerged on the GFS this morning that I’m watching is a casual slowing of the system. It is just enough that forcing would stay west of the warm sector until after sunset. I don’t know if I buy that, but I am watching it.
- The thing to watch will be if models suddenly show a stronger surface cyclone that can back up the low level jet and strengthen surface wind speeds. Right now that doesn’t seem like it will happen with broad model conssensus saying no, but it’s worth keeping an eye on for the next couple of days just in case.