Wet weather to continue, says Texas’ new rain gauge

Published 8:00 pm Thursday, May 21, 2015

AUSTIN – Predicting the weather is never a sure thing, but a new forecasting method is telling scientists that the wet spring in much of the state will segue into a rainier than normal June and July.

“Previously predicting summer rainfall was a coin flip. We didn’t have any tools,” said Robert Mace, deputy executive administrator at the Texas Water Development Board. “Now we have a 70 percent chance of predicting summer precipitation.”

Nobody is saying that the drought that began in 2011 is over. But the forecast, which comes from the water board and University of Texas at Austin, uses more than 20 years of data on the relationship between spring and summer weather to predict what’s ahead.

The new method is a big improvement over the 50 percent accuracy of larger-scale climate models. It draws upon records of atmospheric pressure in the spring, surface conditions on land, and other factors including soil moisture data collected by a recently launched NASA satellite. 

Mace said the forecast fills a mid-range information gap between daily predictions and big-picture models by the National Oceanic and Atmospheric Administration that consider factors such as El Nino and La Nina.

Rong Fu, a professor in UT’s geological sciences department who is principal investigator for the team that developed the method, said its improved accuracy is possible because the model focuses on local, smaller scale processes that determine summer rainfall.

Mace said scientists can begin working on summer predictions as early as January. Releasing those summer forecasts early will enable people to make more informed choices about whether to release water from reservoirs, or when to plant a particular crop, he said.

Pam Prather, owner of Johnson County Feeder Supply in Cleburne, said the information can help farmers decide when to cut hay. It’ll also help her decide what and how much inventory to stock, and when.

Mace said experts began looking for ways to quantify the relationship between spring and summer precipitation back in 2011, when drought was withering crops and wicking up cattle tanks across Texas.

“Much of west, central, and south Texas has not seen improvement,” he said.

“In those areas, reservoirs have either flat-lined or continued to decline.

“I tell people, don’t judge the drought by the color of your lawns. Judge it by how empty your reservoirs are.”

But in Johnson County, south of Fort Worth, Lake Pat Cleburne is 100 percent full.

That’s up from 77 percent one month ago.

After three weeks of rain, the National Guard is wading in with heavy duty tactical vehicles to help with flooding rescues.

“I’m tired of it,” said Prather after learning that the new, mid-range forecast calls for even more rain this summer. “I can’t swim.” 

John Austin covers the Texas Statehouse for CNHI. Contact him at jaustin@cnhi.com