If there ever was a time for “that escalated quickly” in gif form, this day would probably be it. The Storm Prediction Center has outlined an enhanced area for severe storm activity today across Northern and Central Texas. Let’s take a look.

Today’s SPC Outlook. The enhanced area includes the entire DFW metroplex.

The Setup

A small, compact shortwave trough embedded in a broader area of SW flow aloft will overspread the dryline this afternoon, which is 100% going to cause numerous storms in North Texas and Southern Oklahoma.

  • The 850mb winds are reasonably strong but they are more out of the southwest, which is less common with tornadoes on the Southern Plains but more common with giant hail events.
  • 500mb winds are creating vey elongated hodographs, coming in at 60kts or more.
  • Dewpoints are very rich for this time of year, in the mid and even upper 60s.
850mb winds at 5 p.m. shows a SW component to them.
You can see the stronger batch of winds over Texas associated with the compact shortwave at 500mb.

Timing/Evolution

With a powerful but compact shortwave arriving, the conditions in the atmosphere will rapidly improve throughout the day. As storms initially form in the early-mid afternoon, the environment will not be very supportive of supercells, but will rapidly evolve into an atmosphere that will support very powerful supercells by sunset.

Initial storms should start forming 1-3 p.m. across North and Central Texas.
The initial environment is characterized by strong 0-6km bulk shear but very, very poor storm-relative helicity. This environment would result in storms taking awhile to organize without rapid evolution.
By 5 p.m. though, a few supercells should have evolved over North Texas. These should one a giant hail risk along with a low risk of tornadoes.
The environment still won’t fully support strong tornadoes by 5 p.m. — at least presumably. However, tornado warnings on a supercell or two will likely begin happening in the early evening with the biggest risk being hail of baseball to softball size.
The balance today, and what to look for, is how storms evolve from about 4-7 p.m. In most CAMs, storms become very crowded very fast. The HRRR represents a ‘most favorable scenario’ in maintaining dominant supercell mode amidst a lot of multicell clusters.
Any mature, dominant supercells would pose a tornado risk in the 5-8 p.m. hours. This risk is entirely dependent on storm mode/evolution — but a supercell with clean inflow would be capable of a tornado or three this evening.

Overall Thoughts

Today is a day that SCREAMS giant hail. North and Central Texas is a hotbed for giant hail in early April it seems. I’ve intercepted numerous supercells flinging baseballs or larger this time of year in this part of the country.

The tornado risk is something else entirely. The SPC has an enhanced area of tornado risk outlined in North/Central Texas, but I don’t think that risk materializes until 5-8 p.m. or so — but only if storm mode is cooperative.

  • Storms will form 1-3 p.m. with an initial big hail risk.
  • A few supercells will likely evolve in a quickly upscale growing cluster in a rapidly improving environment in the first couple of hours after storm initiation. Expect giant hail in the afternoon/early evening.
  • If you can keep a dominant supercell mode with clean inflow, a tornado risk is going to materialize in the evening with just enough you could convince me a strong tornado or two (EF2+) are very possible.
  • The likely convective evolution will be all roads lead to messy along and north of the DFW metroplex with time.
  • The most likely area for any tornado threat will likely be on the south end of the convective mess, probably along and south of the DFW metroplex.