The modified NUCAPS sounding over Brewster Co TX was more representative of the actual conditions at 20Z versus the regular NUCAPS. A dryline was positioned very near the point of interest and convective initiation eventually occurred  near the boundary in ~1000 ML CAPE air around 22Z.

Modified NUCAPS sounding w/ surface Td near 47F. MLCAPE ~ 1000 J/kg.

Regular NUCAPS sounding w/ surface Td near 54F. ML CAPE ~2000 J/kg.

RTMA Td analysis. Point H is where the NUCAPS sounding was taken from.

GOES-16 RGB at 2150Z showing CI occurring near the dryline.