RENO --  A new mountaintop radar system being installed north of Reno is going to make it easier for forecasters at the National Weather Service to determine if a big rain or snowstorm is on the way.

Meteorologist Dawn Fishler said the new technology at the service's facility on the 8,000-foot Virginia Peak just south of Pyramid Lake will give them a much better eye on the sky as weather fronts make their way across or along the Sierra Nevada.

"It's the biggest upgrade that we've had in probably 20 years," Fishler said.

The new dual polarization radar, or "dual-pol," is better than the Doppler radar that debuted in the early 1990s because it sends radar pulses on both horizontal and vertical planes instead of just horizontal, she said.

Among other things, it will allow forecasters to more accurately determine whether precipitation is falling in the form of rain or snow at various altitudes. The old radar could see precipitation but couldn't differentiate between its types.

The Reno area averages about 2 feet of snow a year and only 7.5 inches of precipitation but within a half hour's drive away at Lake Tahoe, winter storms can drop several feet of snow in the mountains in a single night.

"It allows us to learn more about the shape and distribution of rain, hail, snow," said Dave Myrick, science and operations officer for the Reno weather service office. "It will allow us to see different features of storms."

The new radar also will allow meteorologists to better differentiate weather from non-weather-related echoes that can confuse radar images, including flocks of birds, insects and smoke, Fishler said.

Better information will help the forecasters issue warnings when weather brings trouble to the Reno area, including during severe thunderstorms and flash floods.

The Reno upgrade is part of a $50 million project to upgrade Doppler radars at 160 weather service stations around the country.