Wildfires have burned about 1.5 million acres in Texas since January, egged on by a drought that federal forecasters say is the worst to hit the state in 45 years. Officials with the National Oceanic and Atmospheric Administration say their weather models predict the severe drought that has parched the southern United States will continue to midsummer -- and beyond.

"Predictions over weeks to one to three months suggest the drought will continue, and even intensify, in some areas as we struggle to get any rainfall," said David Brown, director of climate services for NOAA's Southern Region.

"This really is a historical climate event affecting our region," he said, calling conditions "extreme and exceptional."

Drought has hit a wide swath of the southern United States, stretching from Arizona to Florida, with central states like Texas the hardest hit.

The map of current conditions maintained by the U.S. Drought Monitor shows more than half of the state colored red -- indicating an "extreme" drought, expected to recur every 20 to 50 years -- or maroon -- indicating an "exceptional" drought seen every 50 to 100 years.

The so-called "extreme" drought also stretches west, into southern New Mexico and Arizona, and east, into southern Oklahoma, the Oklahoma Panhandle, western Louisiana and southern Arkansas.

Higher temperatures and lower rainfall

Scattered rains have brought short-term relief to some scattered pockets of the region in the past several days, including Texas' Big Bend region, the Red River along the Texas-Oklahoma border, eastern Oklahoma and parts of Arkansas.

But overall, the size, shape and intensity of the drought have changed little over the past week, and the latest weather forecasts aren't promising.

Victor Murphy, who manages the National Weather Service's Southern Region Climate Services Program, said Arkansas could get 2 or more inches of rain over the next five days, leading to significant drought relief there -- and even a short-term risk of flooding.

Northern Louisiana, eastern Oklahoma and northeastern Texas could see 1 to 1.5 inches of rain during the same period, he said. But in south and west Texas, and all of New Mexico, there's no rain in sight.

"The rainfall that fell this weekend should be the extent of significant rainfall we're looking at for the next two weeks," Murphy said. "Looking out over the next month, there are increased chances of above normal temperatures and an increased chance of below normal precipitation over most of the area for the month of May."

That's an especially bad sign, he said, because May is normally the wettest month of the year in Texas and Oklahoma, and in the top three wettest months for Arkansas and Louisiana.

A La Niña-driven 'surprise'
The bone-dry conditions have been driven by a strong La Niña weather pattern that emerged last summer. La Niña -- the counterpart to El Niño -- creates colder than normal conditions in the equatorial eastern central Pacific Ocean. Its effects are wide-ranging, and often include dry winter conditions in the southeastern United States.

Still, Brown said the ferocity of the current La Niña-driven drought was surprising.

"This drought really has been a long time coming. We saw the first instances of it emerging as far back as the early fall season of 2010," he said. "But we could not anticipate how extreme drought would be in some parts of the region."

Last month marked the driest March recorded in Texas since record-keeping began 117 years ago, according to NOAA. It was the third-driest March on record in New Mexico, and the 10th-driest seen in Oklahoma.

The wildfires now scorching Texas may be the most visible side-effect of the drought. As of yesterday, the state's Forest Service was struggling to contain four major fires that covered more than half a million acres.

But Murphy said stream flow, soil moisture and groundwater supplies are also below normal in several Southern states, including Texas, despite a generally wet summer in 2010.

Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC. www.eenews.net, 202-628-6500