Welcome to the end of the work week! I am happy to share that we’re expecting a decent weekend in the weather department. However, today’s weather isn’t going to be so pleasant. Not everyone will be impacted by storms today, nor will all storms be severe. What will be common with most storms (where they occur) today and tonight is heavy rain and localized flooding. Some storms may be strong to severe with a risk of large hail, localized damaging winds, and isolated tornadoes.
We’ve got the standard level 2 risk of severe weather in place this afternoon across the Edwards Plateau, South Texas, South-Central Texas, and in the Coastal Plains. This includes Eagle Pass, Carrizo Springs, Uvalde, Kerrville, Fredricksburg, Boerne, San Antonio, Pleasanton, New Braunfels, Austin, Gonzales, Cuero, La Grange, Columbus, Cotulla, Laredo, Freer, Alice, Kingsville, Beeville, Victoria, Port Lavaca, Hebbronville, Falfurrias, Zapata, and Rio Grande City. Those in the level 2 risk have a 15% chance of having severe weather occur within 25 miles of their location today.
A level 1 risk of severe weather, a marginal risk, includes a pretty large chunk of Texas. The Permian Basin, West Texas, Northwest Texas, Texoma, Big Country, Concho Valley, North Texas, Central Texas, Brazos Valley, Southeast Texas, the immediate Coastal Bend (Corpus Christi), and the Rio Grande Valley are included. It would probably be easier to describe who wasn’t in this risk zone. Those in the level 1 risk have a 5% chance of having severe weather within 25 miles of their location today. As one might expect, this zone is where we can’t rule out strong to marginally severe storms, but we don’t expect widespread severe storms.
I expect some adjustments to where the risk lines are drawn as we get a better grasp on conditions later this morning and into the afternoon. Don’t’ pay attention to exactly where the lines are drawn. If you’re in or near any risk zone that means you should keep an eye on your preferred radar app today. We’ve got a pretty good radar ourselves in our free mobile app. You can download it by clicking the banner at the top of this page.
All storms are expected to produce heavy rainfall and dangerous cloud to ground lightning. Aubdent moisture in the atmosphere will allow for impressive rain rates. Isolated flash flooding along with the ‘typical’ street flooding is expected for folks who end up under a gully-washer. In the severe weather department, we’re mainly concerned about damaging straight-line winds and large hail with the most intense storms. A few tornadoes are also possible, especially in the level 2 risk.
Severe weather hazards are mostly identical in level 1 and level 2 risks. It’s just more likely we’ll see comparatively more severe storms the higher you go in risk level. Ongoing storms this morning along with all their residual outflow boundaries will help dictate the exact corridors of highest storm potential later today. We’ll likely have some storms already ongoing by late morning as the atmosphere destabilizes. Multiple clusters or areas of thunderstorms are expected to be underway this afternoon from Oklahoma and West Texas south through the southern two-thirds of Texas. It’ll seem a bit like summer where we get all sorts of popup storms during the afternoon.
Not all storms are going to produce hail or damaging winds. Most storms will be dumping rain in buckets and produce obnoxious amounts of cloud to ground lightning. We’ll have to watch for storms that can grow upscale into small line segments or clusters. Those would have a comparatively higher threat of producing higher straight-line winds and hail, in addition to very heavy rainfall.
We’ll also see a few of our well-known discrete supercells this afternoon across the Permian Basin southeast into the Edwards Plateau. Like the last couple of days, those are the storms that could produce the very large hail and perhaps a couple of tornadoes. Today’s tornado risk will be dependent on storms interacting with outflow boundaries left over from earlier storms. I don’t believe we’ll be dealing with a substantial tornado risk, but a few spinups are certainly possible.
I really wouldn’t be too surprised if the heavy rain and localized flooding were the main stories today. Although it only takes one rather grumpy supercell with big hail over a city to make for a bad day. We’re going to have a lot of storms by the afternoon from West Texas and the Permian Basin east through Texoma, North Texas, into South Texas and Southeast Texas. Again, only the most intense storms will be producing severe weather. All storms will produce lightning and heavy rainfall. Most storms should be ‘moving’ so that should limit (not eliminate) concern of widespread flash flooding.
By this evening we could have multiple squall lines or thunderstorms clusters underway. One line will be associated with a cool front moving south from Oklahoma into Texoma and North Texas. A second line may be moving east/southeast across South Texas and the Edwards Plateau. That southern line would be in a more unstable airmass with the higher risk of severe weather (hence the level 2 risk).
Storms farther north would be less likely to be severe but would be capable of causing new flooding given saturated soils. Of course, we’ll just have to wait and see how everything sets up later today. This is a messy convective forecast with several variables (weak capping, several sources of lift, lots of moisture and instability, etc). Wind shear values will be highest across South Texas with weaker winds to the north. I’m trying to say that we could just have storms fire up in several areas of the state this afternoon versus a typical ‘spring’ afternoon where we would be focused on the dryline. Don’t worry though, we’ll be dealing with daily dryline storm chances by next week.
So in summary: There will be several storms across Texas today. Most will be gully-washers with isolated flash flooding. The stronger storms may also produce hail and high winds. A few tornadoes are possible this afternoon. Please see the risk graphics above for the zones of highest threat.
Storms will finally begin pushing to the east/southeast tonight into Saturday morning with that aforementioned frontal boundary from Oklahoma. Most of us will enjoy a break from the storms Saturday afternoon through Sunday. We are going to have to watch for isolated storms on Saturday and Sunday from the Texas Panhandle south through West Texas and Permian Basin. That’s your typical dryline event with only a few storms, but those could be hailers.
Next week is looking busy as another upper-level low sets up shop over the southwestern United States. That low will send ripples of energy aloft over Texas – resulting in multiple days of thunderstorm chances. Given the fact we’re in May, it’s almost a guarantee we’ll be dealing with severe weather chances in Texas at times. We’ll deal with next week’s headache-inducing forecast once we get past today. Your friendly neighborhood storm chasers are gearing up for Tuesday – with extended range weather model guidance hinting at an active pattern continuing through the second and third week of May.