When clouds are brighter and whiter in picture, they are thicker and colder at the tops. The chart runs through 24-hour period. When sun goes down, air pressure decreases. Downslope winds that flow outward from a region of dynamically-induced surface high pressure located over a region of elevated topography. During warmer season the pressure is lower in the interior and higher along the coast.
Radar shows rain.
Yellow and orange color indicates heavy rain. Looking at the map, wave cyclone drifted form Arizona into Texas. DHT has a lot of rain but not continuously. Jet stream can be thought out as storm track. The word Trop is Greek for heat.