Much like Sunday, supercells are expected to develop over West Texas and further north into the Texas Panhandle during the late afternoon and evening hours. On Sunday, thunderstorms developed just east of the Texas/New Mexico border around 6:30 PM. Initially, there were only two storms west of Lubbock, both of which became prolific hail producers. After sunset, a number of storms developed further north as the low level jet helped increase warm air advection and the associated lift. The reason I mention this in detail is because those storms left boundaries all over the place. Later today those boundaries are going to act as focal points for new thunderstorms to develop.
Before I get even more nerdy, let me go ahead and outline today’s risk zones so folks who don’t care about weather too much can get on with their day. Above are several graphics showing the overall severe weather risk zones for today.
Brown Shaded Zones – 5% chance of severe weather within 25 miles of any given point (like your house/business). – Low Risk
Orange Shaded Zones – 15% chance of severe weather within 25 miles of any given point (like your house/business). – Standard Risk
Red Shaded Zones – 30% chance of severe weather within 25 miles of any given point (like your house/business). – Elevated Risk
The main severe weather threat at first will be very large, damaging hail. Across the elevated risk zones (red shading), there will also be a tornado threat and straight-line wind threat.
This graphic comes from the high resolution North American Model and shows projected instability values at 6 PM this afternoon. You can see the location of the dryline on this graphic, running along and east of Odessa to Lubbock and Amarillo line. You can see that the dryline bulges out between Amarillo and Lubbock. This feature is often helps increase forcing locally and develop thunderstorms to the east of that bulge. As a whole, instability values over 3,000 joules per kilgoram (J/Kg) support an organized severe weather threat, assuming that wind shear is in place.
This graphic comes from the same model for 6 PM Monday and shows Storm Relative Helicity. This algorithm helps meterologists determine the overall amount of spin available for storms. It looks like this one model has a warm front running along a Canyon, Childress, to Wichita Falls line. To the north of this warm front, wind shear values are over 300 m2/s2. Anything over 200 m2/s2 is favorable for organized thunderstorms, including supercells. To the south of this boundary, shear values are lower but still sufficant for slow moving supercell thunderstorms capable of producing big hail. The threat for tornadoes will be highest along any outflow boundaries left over from yesterday’s convection along with the warm front where shear increases. Additionally, some models are suggesting that a strong complex of storms may track along this warm front overnight. If that does materialize, not only will the threat of large hail continue but a considerable straight-line wind threat could also develop.
I would expect storms to begin developing by 5 PM in the Texas Panhandle and West Texas along the dryline with the possibility of quickly becoming severe. Remember that not everyone will see severe storms today, but refer to the outlook graphics above for the specific chances.
I’ll be chasing in Northwest Texas today and will have the live video feed running for what will end up being the last time on this specific website as our new site will be up sometime later this week.