Last month was the hottest May ever recorded in the Austin area. If that has you worried about what's in store, you have good reason to be: A vicious circle of self-perpetuating heat descends on Texas in the summer.
“Going into May, especially after that near-normal April, things were looking pretty good,” says Victor Murphy, a meteorologist with the National Weather Service. Austin was "nice and wet, not too hot still, and then all of the sudden, you know, who knew?”
Then came week after week of high temperatures with very little rain.
“If you’re concerned about excessive heat or having a hot summer, it's not a good place to be," Murphy says.
Hot temps and long dry spells in May are a predictor of a hot summer in Austin. There's a feedback loop – hot dry weather causes more hot dry weather.
Murphy says it starts with soil moisture.
“Your soil moisture dries out or disappears, which cuts back on evaporation, which cuts back on available moisture” he says. “Which in turn cuts back on cloudiness, which in turn cuts back on rainfall.”
That starts the cycle of heat all over again.
“Drought begets heat, heat begets drought,” Murphy says. “It’s hard to get out of that.”
Murphy says this type of self-perpetuating weather system can lead to something called “the death ridge” when it parks itself over the southern plains, sometimes for months.
What does it mean for Austin?
“We are very certain to have an unusually warm summer, maybe one of our hottest,” says Burton Fitzsimmons, chief meteorologist for Spectrum News in Austin and San Antonio. “I wouldn’t be surprised if we had more than 40, 45 triple-digit days when all is said and done.”
More bad news? This type of heat is becoming more frequent, thanks to climate change and the urban heat island effect, which is caused by metal, asphalt and concrete absorbing more heat than the surrounding land.
“In just the last 10-year period, the average of triple-digit days is now up to 38 per year" in Austin, Fitzsimmons says. "It was 13 per year if you look at the entire 20th century average.”
If you’re looking for any hope you can cast your gaze to a slim chance for rain this Sunday. Tropical systems can also sometimes blow in from the Gulf in the summer, cooling things off.
But, really, when you’re waiting for a tropical storm to save you, that’s just not a good place to be.