The primary forecast concerns over the next few days will be severe weather potential today and more so on Monday. We’re starting off this morning with cloudy skies across the eastern half of Texas as moisture streams northward from the GoM. Marginal low-level moisture and a stronger cap should keep the highest severe weather potential in Oklahoma and Kansas today. I still anticipate high-based thunderstorm development will occur just east of the dryline this afternoon across West-Central Texas into the Concho Valley and eastern Permian Basin. The strongest of these storms could be high-based supercells with a threat of large hail up to the size of golfballs and localized damaging wind gusts. Cloud bases are expected to be very high due to the meager moisture so I really doubt we have tornado issues today in Texas. Any storms that do develop this afternoon will slowly progress to the east and weaken a few hours after sunset.
Later tonight I anticipate elevated thunderstorms will develop, above the cap, in the Big Country into western North Texas. These storms will occur as warm air advection continues to bring rich moisture inland from the Gulf of Mexico. These storms will be rooted above the cap and will not pose a tornado or damaging wind threat. The strongest storms may produce hail up to the size of quarters but most storms will be sub-severe. Development may occur between 11 PM and 3 AM. Storms may try to form into a small cluster as they progress into western North Texas overnight. If storms are able to make it to Interstate 35 in North/Central Texas they would arrive in a weakening state around sunrise Monday.
Once we’re through with today and tonight’s activity all focus shifts to Monday’s severe weather threat. The Storm Prediction Center has placed eastern North Texas and Northeast Texas in a category 3 risk of severe weather – an enhanced risk. The standard category 2 risk runs east of a Gainesville-Dallas-Mexia-Lufkin line. A category 1 marginal severe weather risk includes much of North Texas, Central Texas, Brazos Valley, South-Central Texas, and Southeast Texas. I will say now the best chance for severe storms does look to be in Northeast Texas and points north/east where wind shear levels will be highest in combination with an unstable airmass. By the mid-afternoon hours Monday a surface dryline is expected to be somewhere near I-35 in North Texas. The exact location where that dryline setup will determine who is at risk of severe storms tomorrow afternoon. As usual the dryline is projected to be somewhere near the D/FW metroplex. Some models have the dryline near a McKinney-Dallas line while other models have the dryline out towards Denton to Fort Worth. Locations east of the dryline are at risk of thunderstorms tomorrow afternoon. This wouldn’t be the first time the dryline has ended up further west than expected – so I’m not ready to rule severe weather out in D/FW yet.
This is one of those situations where we won’t know where the dryline will set up until a few hours in advance. Be sure to check back for the latest forecast on Monday morning. All modes of severe weather will be possible Monday afternoon and evening in the enhanced risk zone. Very large hail up to the size of tennis-balls, damaging wind gusts over 70 MPH, and a couple tornadoes are all possible. Low-level wind shear values will be much more supportive of low-level rotation tomorrow than what we will see today. The severe weather threat diminishes with southward extent as a stronger cap is expected to limit or prevent thunderstorm development. Again that’s one of those things we’ll have to continue refining as we get into Monday. Storm development would be possible after 3 PM tomorrow afternoon just east of the dryline in North Texas. Those initial storms would likely develop quickly into supercells. As the storms move east they would be capable of producing very large hail and damaging wind gusts. The most intense supercells could become tornadic. Any outflow boundaries in place tomorrow afternoon from storms tonight could locally enhance tornado risk. Tomorrow is a day we’ll be keeping a close eye on for eastern North Texas and Northeast Texas.