Forecast For River Flows Is Reduced ; Drop-Off By El Nio May Mean Dry Spring

By JOHN FLECK Journal Staff Writer

Federal forecasters Thursday slashed their estimate of this year’s flow in the Rio Grande.

“Winter ended early and abruptly,” said National Weather Service hydrologist Ed Polasko.

The Pacific El Nio has “pretty much fallen off the table,” diminishing the odds of wet weather with little snowpack season left, Polasko said.

The key issue now, he said, is how much snow falls during the next month versus how warm and windy it is. On the plus side, big storms could make up a shortfall in a hurry.

On the minus side, warm, dry winds can “sublimate” the snow, evaporating it before it has a chance to melt and make it into rivers.

Weather forecasts in that regard do not look promising.

“The likelihood is we’ll continue in this warm and westerly pattern for the foreseeable future, and that’s not a good thing,” Polasko said.

The runoff forecast, issued Thursday by the Weather Service and the Natural Resources Conservation Service, reflects deteriorating conditions over the past month after a wet early winter.

It is based on snow measurements taken in Colorado and New Mexico, where mountain snow that piles up over the winter melts into spring and summer water supplies.

There are bright spots, including the Pecos River, which flows from the Sangre de Cristos through Roswell and Carlsbad into Texas, providing water for farmers on its way south. Flow on the Pecos is forecast to be near normal this year.

Communities that get their water from the streams flowing off the flanks of the Sangre de Cristos should also do well, according to Polasko.

But the state’s largest river, the Rio Grande, is expected to deliver only 440,000 acre-feet of water into Elephant Butte Reservoir, the state’s largest water storage reservoir. That is just 77 percent of normal, according to the forecast.

At the beginning of March, levels in Elephant Butte were far below normal, at 598,000 acre-feet of water. The normal March 1 level is 1.3 million acre-feet.

An acre-foot is 325,851 gallons, about enough to supply 2{ Albuquerque households for a year.

Elephant Butte has been left with low levels by below-average snowpack runoff in six of the past seven years.

El Nio, the warm Pacific Ocean pattern linked to higherthan- normal precipitation in the Southwest, was not much of a player this year. El Nios normally do their wettest work in New Mexico in the springtime, but this year’s was gone by February.

Forecasters at the federal government’s Climate Prediction Center now say there is a good chance that a La Nia — El Nio’s drought- bringing opposite — could descend on us by May or June.

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