So. Nevada expected to be hotter, drier

Thursday, Jan. 6, 2000 | 11:22 a.m.

Weather landmarks

The top major weather events of the century affecting Southern Nevada, according to the National Weather Service:

Snowstorms and floods topped Southern Nevada's weather disasters for the past century, but the next century could be dominated by heat and dry weather, experts say.

Weather scientists are peering into the future, piecing together seasonal patterns and evidence of major long-term climate changes from the rings of ancient trees and the sediments in western lakes and rivers.

The West is already experiencing a dry and warmer than usual winter, said Kelly Redmond, chief of the Desert Research Institute's Regional Climate Center in Reno. The Desert Research Institute is the research arm of the University of Nevada System.

From Wyoming to Southern California, water experts have watched the sky for signs of rain or snow, but moisture in the air is well below normal. Las Vegas has had only traces of rain since Oct. 6.

"All around the West it's been warmer than usual," Redmond said. "We don't know why."

Las Vegas has run five degrees above normal this winter, Redmond said. It's been an average four degrees above normal in Tonopah, Reno, Ely and Phoenix since Oct. 1.

Experts say maybe global warming is to blame, or maybe it's the weather pattern known as La Nina. During La Nina, the opposite of El Nino, the Pacific Ocean grows colder than normal and rain that usually falls in California and the Southwest drenches the Pacific Northwest instead.

While no expert will point to any one change in the weather pattern, "a lot are hemming and hawing" about a possible warming trend in the 21st century, Redmond said. Experts are seeing indications that things could get warmer, but without any proof, they're waiting to see, he said.

Urban growth will contribute to that warming if it develops as experts think it might in Southern Nevada.

More pavement and people actually boost local temperatures as the sun is absorbed by more concrete and blacktop. The urban warming trend, which has increased Atlanta's highs by about 3 degrees, is now being seen in Las Vegas, the National Weather Service says.

Although Southern Nevada experienced blistering summer heat in the 1990s, most people escaped in the air-conditioned comfort of their cars or homes, said Ron McQueen, the National Weather Service's local warning coordinator.

Newcomers may not realize because of that modern convenience the potential danger of heat and dry weather in the desert.

But as the valley has grown in the 1990s, at least five people have died of dehydration from the heat.

"Maybe people expect the desert to be hot," McQueen said.

However, a malfunctioning air conditioner in a small apartment or car can create a deadly condition for babies or seniors, who are most vulnerable.

Despite the dangers of heat and its ever-presence in the desert, no heat events made the National Weather Service's list of top weather of the 20th century.

Unofficially, Las Vegas hit a high of 118 degrees and Reno 106 degrees during July 1931, but it didn't make the top weather events, according to the state climatologist's office.

The more recent June 1994 scorcher in Laughlin also failed to make the list.

Laughlin set a state record of 125 degrees on June 29, 1994. From June 24 to July 2 the same year, afternoon temperatures in the Colorado riverside town topped 120 degrees every day.

While the summer's July floods are the most recent event that made the list, if weather experts' hunches are right about coming heat and dry spells, Las Vegas could set a record in the new century for its longest period without rainfall.

The old record is 150 days without any measurable rain from Feb. 22 through July 21, 1959.

In 1944 and 1995 Southern Nevada didn't receive more than a trace of rain for 101 days.

From April 8 through June 28, 1984, Las Vegas went without a measurable drop for 83 days, but it will take some time to top that this year, Chief National Weather Service meteorologist Larry Jensen said. The valley had a trace of rain on Sunday and again on Dec. 21, Jensen said. There was another trace of rain on Oct. 6.

The last major drought that affected Southern Nevada and Southern California began in the mid-1970s and lasted for seven years.