"A lot of that area has only received one-tenth of the precipitation it should have received in the past few months," he adds. "Grasses and crops are already showing signs of water stress. It's dry enough to be a worrisome situation.
"There are no big problems yet, but May is usually one of the wettest months of the year, so if these areas don't get some rain, it could cause a lot of problems down the line. It means we could be in for another hard summer as far as rainfall goes."
That's a polar opposite from the situation in the Amarillo-Lubbock and Midland areas, where some parts of that region have received two to three times the normal amount of rainfall for this time of year, he confirms.
The latest Texas drought officially ended in February and was one of the worst the state has ever experienced. It began in fall 2007 as an unusually wet year for Texas suddenly turned dry. The drought was one of the worst ever, rivaling those experienced by the state in the early 1920s and through much of the 1950s.
Last summer, about 23 percent of Texas was classified as being under "exceptional" or "extreme" drought conditions that occur only once about every 20 or 50 years, Nielsen-Gammon says.
"The lack of rainfall led to the first drought impacts in late fall and winter of 2007-2008. In the summer of 2008 much of the state experienced drought relief with two tropical cyclones, Dolly and Ike, but core areas of the drought in south-central and southern Texas missed out on much of the tropical rainfall. A second straight dry winter followed, and while spring rains shrunk the area of drought in Texas considerably, core areas of the drought continued to degrade," Nielsen-Gammon notes.
"One of the factors contributing to the Texas drought was the El Niño cycle. In an El Niño, with warm east Pacific sea surface temperatures, winters tend to be wet, while the opposite happens during a La Niña. Two consecutive La Niña winters helped to make last year's drought particularly severe."
Since the current El Niño in the Pacific appears to be abating, it could mean warmer and drier weather for much of Texas and the Southwest next winter, he adds.