November has mostly been calm in the weather department across Texas (minus the winter storm in the Panhandle early). However, we will end November with a bang. This continues to be a complicated forecast due to how quickly upper-level lift increases this afternoon and evening, along with uncertainties on exactly how the day will transpire. Frankly, it’s a big pain in the behind, but alas that’s what happens when you get a very powerful upper-level storm system that kicks in your front door. That’s my way of saying there could be a few surprises and I recommend you check back on forecast updates throughout the day. Good sources include your local National Weather Service office (they’re on social media and have a website) along with your local television meteorologists.
Latest Severe Weather Outlook
The early morning update from the Storm Prediction Center did bring some changes to the outlook for this evening. We continue with a level 3 risk across Northeast Texas, and now have more of East Texas included too. The western delineation was pulled back east by about 25 miles, but I really don’t want folks to pay too much attention to the exact line placements. Mother nature doesn’t read maps and neither do thunderstorms. We have the standard level 2 risk east of a line from St Jo to Mineral Wells, and north from Hillsboro to Lufkin to Jasper. A level 1 risk runs west and south of the higher risks. The exact line placements will change in future outlook updates today as confidence in one particular forecast solution increase. Again, don’t pay too much attention on exact line placements. If you’re in any of the risk zones, keep an eye out.
Two rounds of severe weather… the first beginning 3-4 PM in Northeast/East Texas
It now appears probable that we will have at least two rounds of thunderstorm activity today and tonight. The first round will be more isolated to scattered across Northeast Texas and East Texas. These storms will fire up a couple hundred miles east of the dryline in the open warm sector. This development will occur due to rapidly increasing lift from the arriving upper-level storm system.
Because development will be random and not focused to a specific boundary or front, I can’t provide a detailed timeline for specific locations. Just understand that isolated/scattered severe storms may be developing by 3-4PM. Those storms will move east/northeast and could be severe with large hail, localized damaging wind gusts, and the possibility of tornadoes.
Since storms will be discrete versus in a line – and in an environment with strong low-level wind shear, a tornado threat will exist. Thunderstorm chances will increase further by 5 PM and continue through about 7-8 PM. That’s when most of the storms from the first round should be moving into Arkansas and northern Louisiana.
The second round of severe storms fires after sunset near or just west of I-35W/I-35 – impacting all of Northeast/East Texas Tonight
That takes us to round two and back west into North Texas where a dryline will be pushing east. Current indications are that thunderstorm development may not occur along the dryline until after 5-6 PM. This is one of those instances where I once again remind you that the initiation time is not locked in stone. It could happen earlier, or it may happen closer to 7-8PM. The earlier it happens, the farther west the storm risk extends.Assuming storms begin firing at 6-8PM they should do so from Montague county south through Parker down toward Coryell county. In terms of Interstate 35/35W that would be about 25-50 miles west. It may take a bit for storms to actually intensify, but we expect some storms will be severe as they march east across the Interstate 35 corridor – including the D/FW Metroplex, this evening.
Straight-line winds up to 70 MPH and large hail are expected with those strongest storms. I cannot rule out a couple tornadoes with this second round, especially if there are breaks in the squall line or embedded supercelluar storm modes. If we end up with storms firing up right into a squall line the threat of tornadoes will be low – and mostly brief spin-ups. If storms are more semi-discrete then we would likely be dealing with a comparatively higher tornado threat across the eastern half of North Texas from 7 PM to 10 PM. Night-time tornadoes are not fun to chase nor are they fun to deal with in any other occupation. Be mindful of this threat.
The same applies as the storms move east across Northeast Texas and East Texas. A squall line will likely impact all of Northeast Texas and East Texas tonight – weakening with southward extent. Damaging straight-line winds and brief tornadoes will remain possible into the late evening before storms either exit the state to the east or we start losing some of our dynamic forcing after 1 AM Saturday.