LV left high, dry by missing monsoon

Monday, Aug. 26, 2002 | 11:04 a.m.

Longtime Las Vegas residents expect a hot, dry, smoggy summer like this one once in a while. No rain. No summer thunderstorms.

Some scientists, however, think that summers such as 2002 are going to be the norm as Earth's climate warms up.

Nine of the planet's 10 warmest years since record keeping began in the 1880s have occurred since 1990.

National Weather Service meteorologists say 2002 is about to become the nation's second-warmest year and may even be the warmest, hotter than 1998.

Las Vegas is on track to have one of the warmest summers ever, National Weather Service meteorologist Brian Fuis said.

The dry, hot conditions of July carried over into August, and no relief is in sight.

"Warm and dry," Fuis said Sunday of the week's forecast. "It would be a lot cooler if there were clouds and occasional showers."

The high temperature Sunday was 104 degrees, with that mark expected again today, and about 102 degrees on Tuesday.

The threat of late-afternoon thunderstorms for Southern Nevada, the hallmark of what meteorologists refer to as the desert monsoon season, isn't gone until mid-September, Fuis said. But the seasonal air flows that bring moisture from Mexico so far have not reached the Las Vegas Valley -- and they may not come at all.

"Sure there's a monsoon, but this is a desert after all," Fuis said. The weather action is in the Pacific Northwest this summer, and that is keeping Southern Nevada hot and dry.

The storms streaking across the northern tier of states draw the winds from the Southwest, leaving little weather momentum to bring the monsoon's moisture from Mexico, he said.

One result of three years of dry weather is a record low flow along the Colorado River, according to the Bureau of Reclamation.

Long-term relief may be in sight, however. Weather forecasters expect a return of El Nino, the system sparked when the Pacific Ocean warms up and brings moisture to the West from off the coast of Peru.

The first sign of the coming weather system is when fishermen in Peru notice that their catches drop as the warmer Pacific waters appeared, usually around Christmas time. That is why the phenomenon of ocean warming is called El Nino, after the Christ child.

"The El Nino, now looking moderate-ish, fortunately does favor above-normal winter precipitation in your area," drought specialist Rich Tinker said. He is based in the Climate Prediction Center in Camp Springs, Md.

"It's not a sure thing," Tinker said. "But at least it looks promising in bringing drought relief to the Southwest, and we haven't been able to say that for a while."

However, even winter rain won't break the drought's effects in Southern Nevada and the rest of the Southwest.

Months of such moderate rainfall would be needed to relieve the drought, Tinker said.

As for a warming trend, the average surface temperature rose 1 degree in the last century, but most of the warming has occurred since 1970. Another rise between 2.5 degrees to 10.4 degrees is expected by 2100.