2014-04-01 FCST: TX/OK

[James Gustina]

The wild inconsistencies continue on the GFS further out, but a pretty deep, high-amplitude trough is progged to move out of the Four Corners and onto the Southern Plains on the 1st. A 90kt jet streak should eject through the northern Panhandle around 21Z with attendant diffluence region above it. A pretty sharp dryline has been shown to set up in the eastern panhandle and inch east during the day with one hell of a kinematic environment ahead of it. Deep-layer shear values have been looking to be around 45-50 knots with a solid 90 degree turn in the lowest levels of the atmosphere. A relatively broad sfc cyclone looks like it'll set up along the Oklahoma Panhandle/Kansas line and deepen throughout the day, with backed sfc winds wrapping towards the dryline. Really strong, southerly 850s across the warm sector throughout the day have been showing up pretty consistently which should help with the moisture issues to start.

Unfortunately, moisture still looks to be the biggest pitfall of this setup. "Just in time" moisture looks like a very good possibility, with 60F dews not reaching SW OK/SE TX PH until about 18Z which may in turn limit the thermodynamic environment if it's socked in with cloud cover. BUFKIT analysis has been showing a decent enlarging of the hodographs going between 18-21Z as the LLJ kicks up again towards the early evening with deep-layer shear ticking up as a result.

A lot of factors are still in free-fall such as the location of the instability axis and the overall quality of boundary layer moisture (mixing out is something to seriously worry about considering where it is).

 

[Marcus Diaz]

I've seen so many setups like this before. Most of the time they fail with the problems mixing out. The instability axis looks very narrow. And the trends of the models keep the moisture too far south and east of the jet streak. The GFS even hinted at a little warm front action, but this 12Z run eliminated that and even has me thinking I'll stay at home Tuesday. The only hope is if the NAM paints a better picture and closer to home. There's just not enough time for cyclogenesis to occur and pull up quality moisture. The odds of everything falling into place are becoming slimmer with each run it seems. The Tuesday model runs really had me breathing heavy. Now I'm just about to scoff this setup off and call NEXT. But I do want to see what the NAM does with it.

 

[James Gustina]

I'm really hoping it looks better when short-range models get it. The NAM has been extraordinarily optimistic about moisture return on a number of days recently and always fails to account for the pinched turd lows that are too weak to pull substantial moisture which will certainly be something I take into account. I'm also a smidge concerned about the sharpness of the dryline, the last time the GFS showed this we ended up with a diffuse, mixed out "dryline" with no discernible features until storms formed along it.

At this point, I'd be willing to go if it stays within the relatively easy driving range of Childress or Shamrock but I'm not holding my breath if moisture issues keep showing up.

 

[Skip Talbot]

I think the GFS is teasing us a bit still. The shear profiles looked amazing on last night's run, but of course there were the above mentioned moisture and instability questions. If the GFS is too fast at all, those issues are only going to worsen, as our steeper lapse rates hang out further west, and the moisture is further delayed.

The 12z run was a big slap in the face to this setup, deamplifying the trough into broad SW flow and pushing the triple point SE away from this flow.

 

[James Gustina]

GFS is gradually shifting it east with time, looks like SW Oklahoma has the best deep-layer shear/moisture/instability combo. Forecast soundings down that way show pretty big, enlarging hodographs going between 20-00Z. I'm not sure if moisture issues will be resolved like the GFS/Euro are thinking, but I am more than happy to take the optimism. Looks like two solid chase days might be setting up across the southern Plains.

 

[Jeff Duda]

This is why I don't bother getting excited about an event until it's 2-3 days out. The GFS has been progressively pushing this event back. On today's 12Z run there's almost no overlap between the unstable air and the sufficient dynamics for a severe weather event. If you want more than 500 J/kg SBCAPE, you're gonna have to settle with 40 kt WSWly h5 winds at best on top of 20-30 kt S/SWly h85 winds. Not horrible, but not great either. The GFS also depicts a slight warm layer above the PBL which keeps things from ever going fully uncapped. Plus the forcing mechanism (the dryline) remains well to the west of the instability axis, so I'd have to even question initiation based on these progs. Finally, the GFS shows the surface low filling in slightly during the day Tuesday, so the dynamics may suffer even more.

When I checked the 18Z GFS yesterday I was surprised to see that it made Wednesday seem like a better day than Tuesday. Now today's 12Z has the system delayed even more so that Thursday is almost looking better than Wednesday. If these trends continue, Thursday will end up being the day. The GFS is quite notorious for slowing systems down after all.

 

[Marcus Diaz]

Yes, Tuesday has been progressively falling off the past few runs. Wednesday looks more like a classic Spring setup with Thursday having insane shear but you'll be in the jungles. The Euro has been consistent with Wednesday being big and hanging that SFC lowin the OK panhandle vicinity. Now its like the GFS came into full agreement with the Euro. The NAM has been bumping the moisture levels over 5 degrees more than the GFS the past couple days. So now its a wait-and-see game with the NAM to see if there's any hope for Tuesday.

 

[Brett Roberts]

12z ECMWF is much slower than yesterday morning's run, continuing the trend seen on all guidance the past 24 hours. With that, I think the potential for Tuesday can probably be relegated to the marginal category. Strong pressure falls and associated return flow/shear ramp-up will not commence in earnest until relatively late, and upper-level forcing will likely struggle to arrive in time for Tuesday afternoon/evening. As such, I can see a marginal and conditional setup over parts of C and N TX, but not much more unless this slowing trend reverses (which is rare). It's really a shame, as Tuesday looked much nicer from a chasing standpoint yesterday than Wednesday does even with the newer, slower solutions.

 

[James Gustina]

Just realized I mislabeled the chart up there^. Tuesday looks like it took a shotgun blast from the 12Z. The cyclogenesis/moisture return issues look to have come true. The bulk of upper-level dynamics won't be in place in time per the Euro, with the jet streak not rounding the base of the trough until what looks to be late Wednesday. It's still not within WRF/SREF guidance but I doubt this recovers looking at the way it's going.

 

[James Gustina]

This setup refuses to go away. Capping looks like the biggest issue, but with surface temps looking to hit 80 per the NAM and SREF, I would be surprised if at least an isolated storm doesn't go up. The other issue is that any surface-based convection will likely start dying off towards sunset due to the stabilizing of the boundary layer.

That said, shear still looks pretty impressive for an isolated supercell or two down by Wichita Falls, with 0-6 km shear between 40-50 knots and pretty sizable instability on the order of 2500 j/kg of MLCAPE. Moisture is already moving into place the day before removing any concerns about rapid moisture return the day of and mixing out shouldn't completely wipe boundary layer moisture. Low-level mesocyclone maintenance and tornado chances look like they'll have a pretty narrow one hour window before 00Z, but a nicely structured supercell all by itself seems to be a more distinct possibility along the dryline.

 

[Brian McKibben]

Just pulled a very intriguing sounding from the 3/31 18z Nam for a sounding basically over Norman-ish area. The low level shear has some great turning along the warm front. Plus the cap looks pretty weak. If an isolated cell can fire, it could be quite a show.

 

[James Gustina]

Tomorrow is looking very dependent on that warm front hauling it north to at least Lawton if there is gonna be anything worth chasing. I'm encouraged by a smaller sfc cyclone forming just west of SPS on the dryline but capping and mixing out still concern me. The tornado threat is looking like almost zero but a pretty looking elevated LP down by the Red River going into the evening would not surprise me with the instability and overall shear environment that looks to set up.