Winter Who? - It feels more a muggy spring day across North Texas this late morning. We are in mild conditions this morning with temperatures in the 70s at 10:08 with no sun at all.
Actually, now that you think about it, no sun is actually a good thing in these scenarios, because it is dry now, but strong to severe storms will be possible this evening and overnight, where the Storm Prediction Center has introduce a "marginal" risk for severe storms for much of West Texas and some parts of the North Texas coverage area, including some parts of the DFW metro.
Strong to possibly severe storms will be more likely in the areas shaded in the darker green. Though it will not be a widespread event, some of the strongest storms could produce large hail at times, and maybe some gusty winds. A brief spinup cannot be ruled out.
Sounding Analysis - This is analyzed from a weather balloon that is launched multiple times each day. Pay attention to the upper left part of the sounding, most notably the red and dotted brown lines. The solid red line represents the temperature and the dotted brown line represents the air parcels, AKA, instability. The red line intersects the dotted one at 850, which means that there is currently a cap in place. A cap serves as a layer of warm air that suppresses the development of severe thunderstorms. If we can get the capping inversion to erode this late afternoon, a few supercells will be possible within the marginal risk area.
IF the cap can erode this evening, there will be sufficient buoyancy and vertical shear (shown in the sound) for storms to produce some large hail, a few bowing segments, and one or two tornadoes. As details become more clear, an upgrade may be warranted in later outlooks, so stay tuned.
Timing - Keep in mind that this will mostly be an overnight event, be aware as this may make for a wet commute during the pre-dawn hours on Tuesday. We will continue to see rain at times for the rest of the day today, but not all day. There will be a small window this evening where any isolated thunderstorm that develops has the potential to turn marginally severe with large hail and damaging winds. Then, overnight, a complex of showers and thunderstorms overspreads north Texas overnight, but some embedded supercells will be possible within the complex. Those storms will have more of a damaging wind and hail threat. Anything leftover during the pre-dawn hours will likely be just rain and some thunder, so pack an umbrella and be prepared to drive slowly tomorrow morning.
We will provide updates throughout the day, so be sure to check back frequently.