Those across the eastern half of Texas are waking up to low-level overcast and some mist. That’s a sign that moisture levels are starting to increase as our arctic airmass has finally eroded. Temperatures this afternoon will be quite pleasant and spring-like, a big change from earlier this week. Tomorrow will be similar, although we may have a cool front nose its way south into portions of the eastern Texas Panhandle, Northwest Texas, and Texoma. If that happens we’ll see the 50s and 60s for those folks versus the 70s and 80s expected elsewhere. We’ll let those automated weather apps have fun keeping you updated with the temperature forecast. We’ll be focusing on the potential for strong thunderstorms Saturday morning and a more widespread soaker expected next Tuesday.
Friday Night and Saturday
Taking a look at water vapor imagery this morning we can easily make out our next weather marker. It is located several hundred miles west of the California coast this morning. It is expected to begin moving onshore this evening and fully make it on-shore by tomorrow morning. This is important since we want to get weather balloon data ingested from the system. That weather balloon data (upper-air network) will tell us specifics about the strength of the upper-level shortwave. Until then, weather models are doing more ‘guesstimating. The more data we can ingest into weather models the more accurate their outputs. At least that’s the theory! It isn’t always a proven fact.
Severe weather outlook
A level one risk of severe weather is in place Friday night into the pre-dawn hours on Saturday across the Red River Valley, Texoma, northward into the eastern two-thirds of Oklahoma. It appears a cluster or several thunderstorms will erupt late Friday night and move northeast. Some of those storms may be strong with the potential of producing hail. Scattered showers and a few storms are possible across Northwest Texas, the Big Country, North Texas, and Northeast Texas Friday night. Some storms may produce small hail as they move northeast.
A level one risk of severe weather, a marginal risk, is in place Saturday morning and early Saturday afternoon for North Texas, the Brazos Valley, and Southeast Texas. A level two risk of severe weather, a ‘slight risk’ (a stupid name, but alas it’s what it is called) is in place for Northeast Texas and portions of East Texas.
The level one risk runs east of a Muenster to Weatherford to Waco to Bryan to Houston line. The level two risk runs along and east of a line from Honey Grove to Cumby to Mineola to Tyler to Mount Enterprise to Center – and points east into Lousiana and Arkansas. In fact, the level two risk runs all the way to Alabama!
Those in the level one risk have a 5% chance of experiencing severe weather within 25 miles of a given point (like your house). That chance increases to 15% if you’re in the level two risk. I don’t want folks getting tied down on the exact placement of the colorful lines. Storms don’t care where we draw lines and we’re still three days away. The outlooks and their pretty lines are going to change some as we get honed in on a particular solution.
Hail seems to be the most common severe weather hazard on Saturday. Strong (but sub-severe storms) may produce dime to nickel size hail. Those that achieve severe limits may produce hail in the quarter to half-dollar range. The potential for localized damaging wind gusts of 55 to 65 MPH and an isolated tornado will be in the level 2 risk zone.
We do note that the threat of tornadoes does increase across portions of Louisiana, Arkansas, Mississippi, western Tenessee, and into Alabama on Saturday. Like the last two severe weather events, we seem to be on the starting line. Storms really get cranking once they’re east of Texas.
Scattered showers and thunderstorms may be underway by Friday night into the pre-dawn hours Saturday across the Concho Valley, Big Country, Northwest Texas, Texoma, North Texas, and Northeast Texas. Most of this activity may be your typical ‘warm air advection’ convection that happens when we get those strong southerly winds at the surface and aloft. Some of the storms may produce small hail and frequent cloud to ground lightning.
As the bulk of the thunderstorm activity moves east of Interstate 35 by mid-morning we anticipate an uptick in strong to severe weather potential in Northeast Texas and East Texas. In those regions, we’ll see instability values increasing as the upper-level storm system arrives with increased lift. Wind shear values will support organized thunderstorms. Large hail certainly could become more an issue along with the possibility of localized damaging winds.
If storms maintain a linear mode (squall line) the threat of tornadoes would be low, but not zero. I certainly can’t rule out a brief tornado or two if the squall line starts to develop ‘kinks’ or enhanced areas of damaging wind. Any discrete storms that were able to tap into that more unstable airmass at the surface would need to be watched for signs of low-level rotation. I’m not sure that process will be able to occur before storms exit Texas to the east/northeast by the early afternoon. That possibility is one we’ll get a better handle on as we get closer to Saturday (hopefully by tonight or Friday morning).
As we move into the mid-afternoon hours we may have scattered thunderstorms occurring along a frontal boundary (essentially a nearly stationary dryline) across the piney woods of East Texas west/southwest toward the Brazos Valley and Southeast Texas. These regions will be removed from the more favorable upper-level lift and low-level wind profiles will be less favorable for organized severe weather. Some of the storms certainly could produce marginally severe hail and localized wind gusts of 45 to 55 MPH, but the ‘cap’ will also try to squash the storms. Thunderstorm activity is expected to decrease by the evening hours as the upper-level storm system completely departs the region.
Potential alternatives for Saturday
If this whole event speeds up we may have to push the starting time ahead by a few hours, with the potential for some stronger storms in Northeast Texas before sunrise on Saturday. This would also tend to push the higher severe weather threat east of Texas (compared to the ‘borderline’ threat we have now). A slower solution would likely result in the threat zones shifting a bit farther west. This does not look like a ‘big’ severe weather threat in Texas at this time, but we’re still 3 days out.
It is often the ‘little things’ we can’t see too far in advance that can enhance or reduce the threat of severe weather. If we end up having ‘discrete’ storms in Northeast Texas or East Texas late Saturday morning that become surface-based we would have to watch for the threat of a few tornadoes. If we end up having widespread rain/clouds that threat would be lower, but some hail and gusty winds would certainly remain possible. Let’s get the upper-level storm system on-shore tonight and we should be able to more confidently provide a forecast tomorrow.
Monday Night into Tuesday
A more widespread thunderstorm event is possible Monday night and on Tuesday across Texas. Let’s get past the Saturday system before we focus too much on next week. However, the potential for severe thunderstorms and heavy rainfall potential are evident. This event also looks like it would be much more of a statewide event versus Saturday. In fact, I’d say this one could be our first big spring rain maker for the state as a whole. We’ll deal with it as we get closer, but it is a good reminder that we are now in our spring severe weather season.