Tuesday, February 01, 2005
Copyright © Las Vegas Review-Journal

Wet January further alleviates drought

Las Vegas gets 2 inches of rain in year's first month, fourth-highest total on record

North Las Vegas Department of Public Works employees work on the Las Vegas Wash's Three Bridges Project on the south side of Cheyenne Avenue. The project is funded by the Clark County Regional Flood Control District. Photo by John Gurzinski. Click image for enlargement. Graphic by Mike Johnson.

If easing the drought was her New Year's resolution, Mother Nature is off to a good start.

Last month ranked as the fourth-wettest January on record, capping a five-month span that saw more rain fall on the Las Vegas Valley than in any September through January in 70 years.

"This is the kind of winter we've needed. This is the kind of winter we've been waiting for for the last five years," said Kenneth Clark, expert senior meteorologist for Accuweather, a private weather service.

Though Southern Nevada has only seen "about a half a dozen major rain events" over the past five months, Clark said the storms have been substantial enough to wash away both roads and records. "They've been deep, very slow-moving storms that gather a lot of moisture," he said.

Take December. For all but two days that month, the official National Weather Service gauge at McCarran International Airport registered no measurable rainfall. But on Dec. 28 and 29, 2.1 inches of rain fell at the airport, enough to make last month the wettest December on record.

That came on the heels of the valley's fourth-wettest November since record keeping began in 1935.

January's 2-inch rain total was spread more evenly than December's two-day downpour, but 2005 has already seen two record days of its own. McCarran received four-fifths of an inch of rain on Jan. 3 and one-quarter of an inch on Jan. 28, the most ever recorded on those dates.

From Dec. 28 to Jan. 5, Las Vegas got twice as much rain as the valley usually receives in four months. A deadly avalanche on Mount Charleston and floods in northern Clark County soon followed.

At Lake Mead National Recreation Area, wet weather is the suspected cause of a rock slide that buried part of the Pearce Ferry Road on the Arizona side of the park. Park personnel discovered the damage Monday morning. Special equipment will be needed to clear a large boulder that slid onto the road.

Also, a number of backcountry roads remain washed out, including the unpaved route from State Route 169 to the St. Thomas town site.

But the benefits of rain are just as easy to see at the lake, said Lake Mead spokeswoman Roxanne Dey.

Already, wild flowers are popping up along the road to Willow Beach, downstream from Hoover Dam. Lake officials are predicting an enormous bloom this year, Dey said.

The colorful foliage should peak late this month or early next month. Dey said the best places to take in the colors will be along the Lakeshore, Northshore and Temple Bar roads, as well as the Railroad Tunnel Trail.

Rain has not had a measurable effect on the amount of water in Lake Mead, but it probably has resulted in some reduction in water demand. Exactly how much is difficult to quantify, said J.C. Davis, spokesman for the Las Vegas Valley Water District.

Final use figures for January are still being compiled, but water demand in Las Vegas dropped 4 percent during the last four months of 2004.

The reason wet weather does not have a more obvious impact on local water use, especially during the winter when demand is at its lowest, is because the few storms we do see rarely linger, Davis said. If it only rains once or twice in a month, residents often don't have the time or the inclination to adjust the clocks on their sprinkler systems.

Also unclear, is the impact of recent rain on air quality in the valley.

Wet weather, especially in February and March, can trigger elevated levels of pollen and mold spores, said Monte Symmonds, senior monitoring technician for the Department of Air Quality Management. But, he added, the rain can also help clean the air of dust and other particles.

The wettest January on record was in 1995, when 3 inches fell in Las Vegas. The valley received 2.41 inches in January 1949 and 2.18 inches in January 1979.

The average annual rainfall in Las Vegas is slightly less than 4 1/2 inches. In 2004, the valley got 7 3/4 inches, it's fourth-highest yearly total on record.

Clark, the Accuweather meteorologist, said the forecast for the next 10 days looks pretty dry, but he expects the recent trend of above-average precipitation to continue for the next few months because of the weak-to-moderate El Niño weather pattern that began to develop last summer.

El Niño years, when the Pacific Ocean warms off the coast of Central and South America, are usually wet years for the American Southwest.