Has bad air helped drought?

The temperature inversion seemed a nasty visitor to northern Utah.

Throughout January and for most of the first half of this month, its cold temperatures locked in air pollution. Brown-gray valley air triggered health warnings against outdoor exercise. Fireplaces went unused through "no-burn" days. Smog made eyes sting and reduced visibility as drivers negotiated the icy roads.

But, surprise! The inversion actually was a friend — in one crucial respect.

"Things have been cooler than normal, and that's good, that's what we like," said Brian McInerney, hydrologist for the National Weather Service in Salt Lake City. He spoke Monday at NWS offices on North Temple during a meeting of the Utah Water Users Association.

The inversion's frigid temperatures have kept snow on the ground in many low-lying areas. While residents are annoyed with the big dirty berms towering beside driveways, making backing more difficult than usual, hydrologists are pleased the frozen precipitation is hanging around.

"Our low-elevation snowpack is as high as we've had it in years," McInerney said.

Also, deep snow accumulations on mountaintops are geographically limited, but the thin snowpack at lower elevations covers a much larger area. So its contributions could be important should they reach reservoirs.

Deseret Morning News graphicSnowpack possibilitiesRequires Adobe Acrobat.

"We've got a lot of snow down here in lower elevations," Randy Julander, snow survey supervisor for the U.S. Natural Resources Conservation Service in Salt Lake City, agreed after the meeting.

When January weather is relatively warmer, as it often is at lower levels, some of the snow melts, some evaporates and much of the rest soaks into the dry ground. It doesn't add to the flow of water going to reservoirs.

"If it holds for the next month or so, it could contribute in a fairly significant way to runoff this spring," Julander added. If it melts in March and flows into streams and rivers, it could head straight into reservoir storage. "That could help out a great deal," he said.

With Utah battling a years-long drought, any snow available for the runoff will be welcome.

The state's snowpack is above average. But it may not stay that way. Julander showed conferencegoers three scenarios for the spring runoff.