2014-04-13 FCST: KS/OK/TX

[Brett Roberts]

I've been leery of Sunday since this wave first came into view, given the likelihood of cold high pressure building down the Plains right on its heels. I would much prefer for Saturday (4/12) to be a chase day, as the cold air will still be out of the picture. Unfortunately, the latest data has continued with a slowing trend that doesn't bode well for that.

So, we might as well take a look at what we've got on our plates for Sunday, far as it may be from ideal. Today's 12z ECMWF and CMC both lag the upper energy enough that the surface low remains somewhere around DDC-WWR by late Sunday afternoon, with a dryline extending southward along the OK/TX border into NW TX. The ECMWF forecasts low-mid 60s dew points across the warm sector, with convection breaking out down the dryline by 21z. Taking the ECMWF literally in all facets would suggest a pretty good chase day by early April standards. The 12z GFS stands in stark contrast, with a cold front crashing through most of OK and N TX earlier in the day.

Given trends and recent model performance, I'm inclined to side more with the ECMWF/CMC. Even with a slower solution, however, I definitely fear the shallow cold airmass lurking across the central Plains by Sunday afternoon will try to crash the party. We saw a great example of this happening last year on April 17, when the frontal zone set up as much as 200 mi. S of where global models like the ECMWF indicated even 24 h beforehand. The pressure gradient immediately N of the surface low on all the models right now is pretty scary. So, my best guess right now would place the triple point somewhere closer to SW OK or even the Red River, with the cold front adjusted SE accordingly. The movement of the cold front during the afternoon and evening, as well as the degree of low-level backing in the warm sector, would determine whether a decent chase day could still be salvaged. But we've got many model runs to go...

 

[James Gustina]

Not liking where the 12Z GFS is putting that cold front, it's looking like a watered down April 17th along the Red River and into the Metroplex. Just taking a look at the 850s, the winds/gradient looks scary in advance of that front. The thermodynamic environment looks decent down along the Red River and it doesn't appear capping will be an issue, it's just a question of whether or not the dryline can advance far enough east and shoot off some semi-discrete storms before the cold front comes and obliterates the environment.

 

[Zack Hargrove]

I have a bad feeling you will have to be in TX to get a decent setup Sunday based on the GFS. But northwest to central TX could have some real potential.

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[Brett Roberts]

The foreign models have really accelerated the cold front as compared with yesterday's runs, so any hope of a chase in high-quality terrain is all but gone. The current consensus has the front surging to a position somewhere 50 mi. either side of I-44 by 00z Mon. With the warm sector squeezed so far to the S, I fear capping may still be an issue even Sunday, away from the undercutting front. If storms can develop along the dryline or over the open warm sector, the environment looks impressive in some aspects, but winds around 850 mb are more veered than I'd like to see.

As others have mentioned, the most likely target area for now is N TX, perhaps centered on the DFW Metroplex. The potential exists for a significant severe weather day in that area, but capping and directional shear are possible limiting factors. Even if the full potential is realized from a meteorological standpoint, terrain and population density are likely to make this a hairy chase day. The season being what it is so far, though, I'm sure I'm not the only one (in reasonably close proximity) who'd give it serious consideration.

 

[James Gustina]

I've been debating this one with a friend. This has uncanny similarities to a certain April day last year that I still wish would jump off a cliff with concrete shoes on. The dryline looks like it maintains it's identity at least until 00Z and moisture shouldn't be an issue, but the dreaded back-veer-back profile looks like it might make it's first appearance of the season in Texas. Add in that it looks like chasing into the Metroplex, which is a very scary proposal, and I'm not quite sure if I want to touch this one.

 

[Tim Supinie]

As others have mentioned, I'd plan to be as far south of the cold front as you dare to give it a good ways to blast ahead of guidance. The 12/12Z NAM forecast soundings for 21Z on the 13th between Cleburne, TX and Ardmore, OK just west of I-35 are probably about the best you could expect tomorrow. The temperature profiles are passable, but the shear is a little weird around 700 mb, which could impede storm organization, should something develop. If I were chasing tomorrow (which I won't be; prior commitments again), I'd set up in either Marietta, OK or Gainesville, TX and see what happens. The presence of the Red River is the only factor keeping me from suggesting Gainesville unequivocally.

From where I sit, if there's nothing to see between Ft. Worth, TX and Pauls Valley, OK tomorrow, there's nothing to see, period.

 

[adlyons]

Waiting on 00z data right now but my tentative target is Gainesville TX. Area looks to be far enough south from the cold front, and has plenty of options on the chance that storms go up further north, South or where ever. The red river has a few crossings in Gainesville, and Whitesboro which is just a short hop east down US 82. Latest hi res guidance as of 23z shows the dryline a little more diffuse and further east. Given the pretty strong moisture advection tonight, im willing to be the RAP is a little off with moisture. Im not sure if we will have mid 60's tomorrow, but moisture should not be an issue as the rap is painting. Shear looks to be alright. Back veer back is in play, which could cause some issues, but hodos look a little better than they did in previous runs. In terms of thermo environment, things look good. Plenty of instability with minimal capping now. Overnight elevated convection should help to weaken the cap enough to where the dryline and whats left of the lifting from the trough should be able to get it done. Waiting on convective models to see what the general storm organization looks like. 4km nam did break discreet storms on the river near 21 22z sunday. If this pans out it looks like a decent chase day. Now to wait for the 00z suite and morning of obs.

 

[James Langford]

Becoming concerned about the fairly heavy elevated convection showing up on most of the models for the morning hours for the southern target. It does seem to clear out by about 1 pm or so, but will we have enough heating to overcome the cap? We are probably going to target along the dry line, likely somewhere along 287 between Decatur and Wichita Falls and watch for the best cu.

 

[dixiealleyspotter]

Near Abilene, heading to target area north of Dallas.... been without internet for a while..... sure is looking like forcing already has passed. Think it's a total bust?

 

[Tim Supinie]

I'd hesitate to call most anything a total bust at noon. Looks like there's some slightly deeper cumulus southwest of Wichita Falls and northwest of Abilene on the 1630 UTC satellite image. Some shallow cumulus in Oklahoma; nothing of note yet there.

 

[dixiealleyspotter]

Stopped for Nowcasting in Weatherford, TX.... Loving the visible satellite. Adjusting target area to Wichita Falls..... would you agree storm motion w-e @ approx. 35mph? I would love to still be north of Dallas this evening if storm mode hasn't gone MLCS. At 35mph I think I can manage.

 

[Mark Meyers]

Looks like SPC will issue a tornado watch in the next few hours with initiation for surface based storms by 20Z. Central, Eastern Oklahoma and a part of Northwestern Texas will be under the gun. NWS FWD simulated reflectivity shows storms developing near Palo Pinto County by 2pm and moving east towards the metroplex by 4pm. More storms may develop along the dryline from near the I35 corridor in Southern Oklahoma down through Gainesville and near or west of Denton by 4pm ...all per NWS FWD simulated reflectivity. HRR also shows convection developing near or east of Wichita Falls by 20z with more development further south towards I20. Storm motions appear to be east or slightly east northeast today.