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Published August 04, 2013, 09:13 AM

Drought still lingers in much of western US

DALLAS — With a lot of recent rain, lush lawns and green pastures manage to mask the Texas drought. Still, it retains its grip on the state and most of the western U.S., with nothing to indicate it will ease anytime soon.

By: Michael E. Young,The Dallas Morning News (MCT), Associated Press

DALLAS — With a lot of recent rain, lush lawns and green pastures manage to mask the Texas drought. Still, it retains its grip on the state and most of the western U.S., with nothing to indicate it will ease anytime soon.

“The thing about this rainfall is just the character of it,” said Dr. Robert Mace, who heads water science and conservation at the Texas Water Development Board. “We aren’t getting the big rainfalls with lots of runoff. We get a little bit of rain and then it’s sunny, dry and windy.”

The latest outlook, which runs through Oct. 31, says drought will persist or intensify across most of Texas, the Plains and Rocky Mountain states, all the way to California. More than 92 percent of Texas is in moderate drought or worse, with 67 percent in severe, extreme or exceptional drought.

The reservoirs tell the story, Mace said.

Statewide, reservoirs are at 63.9 percent of capacity, the lowest level for late July since 1990. That is 10 percent lower than a year ago and 20 percent below normal levels.

In parts of West Texas and the Panhandle, reservoirs measure in the single digits. Lake Abilene is about 9 percent full. E.V. Spence, in Coke County, is less than 6 percent of capacity. Electra City Lake, west of Wichita Falls, is empty, according to the water development board.

Several began their slow decline at the end of the last century, Mace said.

The situation is better around Dallas, where reservoirs average 79.5 percent full. Still, water levels are up to 40 percent lower than a year ago.

Texas has been in drought since 2011, the driest year on record, said John Nielsen-Gammon, the state climatologist and a professor at Texas A&M University.

“As far as persistent statewide droughts go, there have been maybe three periods that lasted this long — 1909 to 1912, 1962 to ’66, and the drought of record in the 1950s,” Nielsen-Gammon said. “So far we’ve been drier than any of those long-haul droughts other than the ’50s.

The last year with above-average rainfall at Dallas/Fort Worth International Airport was 2009. From 2010 through 2012, total rainfall was almost 20 inches below normal levels. This year has been no better, with rainfall about 4.5 inches below normal.

“And there hasn’t been anything promising in either the Atlantic or Pacific” to indicate a change in the weather patterns, Nielsen-Gammon said.

In the world of long-range climatology, warm and cool shifts in certain areas of the oceans have emerged recently as major factors in rainfall and temperature thousands of miles away.

Persistent drought in the western U.S. has been linked to warmer than normal water temperatures in the northern Atlantic, and average or cooler temperatures in the eastern and northern Pacific.

El Nino and La Nina are part of the language of weather in the U.S. Now climatologists talk about the Atlantic Multidecadal Oscillation and the Pacific Decadal Oscillation as well, both recent discoveries.

“I hadn’t really heard much about the PDO or the AMO until 2011,” Mace said.

Looking back, though, he can see how this cool phase of the PDO began affecting West Texas reservoirs 15 years ago.

“The key word in Pacific Decadal Oscillation is ‘decadal,’ because it seems to last about 30 years, and we’re 15 years into it,” Mace said. “John Nielsen-Gammon has said this means we have a greater propensity for drought for the next 10 or 15 years.”

Likewise, the AMO has been in a warm phase since the 1990s, a pattern linked to hot, dry weather in the southwestern U.S. And the eastern-central Pacific, home of El Nino and La Nina, was cooler than normal from mid-2010 through early 2012 and neutral since then, another factor in drought.

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