Natural gas generation never drops below ~40% period in this state, the novelty here is its losses from heat were covered to the tune of 35% of the mix last Tuesday.
PV generation maxes out at ~12GW, the bulk of our renewable energy comes from wind but it isn’t blowing this week ergo outsized natgas generation before the sun is up.
Vegetation doesn’t do anything for humidity, see: Southeast Asia, Subsaharan Africa.
Texas has zero alfalfa production, you’re imagining the desert southwest 1000+ miles away from Houston in an entirely different climate.