At 2100z on 10 November 2021, there were three surface low pressure centers along the Southern Plans and Texas with a cold front pushing cool dry air eastward from the desert and mountainous terrain of the western US. The warm side of the cold front has southeasterly winds from the Gulf of Mexico moving onto land from the warm side. Figure 1 shows a cold front extending through central Kansas, Oklahoma and western Texas. Due to differences in the moisture between the airmasses on either side of the front a dryline feature can be seen extending from the Texas-Oklahoma boarder south to Mexico.
Figure 1. shows a surface analysis of the contiguous US at 2100 UTC 10 November 2021. It shows a cold front extending vertically across the US and a dryline feature ahead of the cold front in central Texas. Source: NOAA WPC Surface Analysis Page
As this cold front progresses eastward, it acts as a lifting mechanism, forcing warm moist air upward into higher altitudes. If there are sufficiently large lapse rates along the warm side of the cold front, an environment favorable for the formation of large Convective Available Potential Energy (CAPE) is likely to develop. Figure 2 shows significant lapse rate values over the Texas-Oklahoma boarder, extending southward into central Texas and northward throughout Oklahoma. Regions of large CAPE values and large lapse are great environments for thunderstorms and hail to develop as the forcing of a warm moist air parcel is cooled at a rate quick enough to condense and freeze water vapor before it falls back to the surface.
Figure 2. is a map showing mid-level lapse rates at 2100 UTC 10 November 2021. Values are shown along contours. Higher values are shown with warmer colors. Source: SPC Mesoanalysis Archive
Large CAPE regions are seen vertically throughout central Texas, through Oklahoma, and northward onto Kansas and Missouri. These high CAPE values above 1000 J/kg are seen throughout the entire southern part of the warm side of the cold front as it passes through the Southern Planes region and continues eastward. The significant lapse rates, CAPE values and presence of moist air over Oklahoma were significant to produce hail and significant winds as reported on the SPC Storm Reports page for 10 November 2021.
Figure 3. is a 100 mb map showing mixed layer CAPE values. Shaded fill regions indicate CIN values and red contours are CAPE. Wind barbs are bulk shear in knots. Source: SPC Mesoanalysis Archive