I think the combination of the lowest temps in last 30 years, with sustained mucher colder temps than average over last 4-5 days with overcast sky (so there is

I think the combination of the lowest temps in last 30 years, with sustained mucher colder temps than average over last 4-5 days with overcast sky (so there is no residual heat from mild Texas winter day), and that 50% of the state's wind turbines were made inoperable by freezing rain a few days ago might make it a once in a century event.