SALT LAKE CITY (AP) -- Heavy fog conditions in northern Utah could lift as early as Wednesday.
The cloudlike mass of fog that descended over parts of Salt Lake, Davis and Cache counties last week is the result of high pressure and stagnant air in the lower layers of the atmosphere. A weak trough coming in Tuesday morning might bring some relief, forecaster Eugene Van Cor of the National Weather Service said Monday.
"There's just enough of a wiggle in the air to help clear things up early Wednesday," Van Cor said.
The Utah Division of Air Quality has issued a "yellow" alert for Salt Lake and Davis counties, meaning the use of coal and wood-burning stoves is optional. Residents also are advised to drive less by combining trips or using mass transit.
State officials said people with respiratory or heart disease, the elderly and children should avoid spending much time outdoors until the air clears.
Meanwhile, Cache County residents already have received some respite from the thick shroud of fog, which prompted the Bear River Health Department last week to issue a "red" alert to residents.
Utah, Weber and Cache counties were having a "green" day Monday, which means they have healthy air conditions.
The conditions in northern Utah aren't unusual, according to Van Cor, who recalled similar conditions a year ago.
"It's the jetstreams north and south of us around this time of year that lock us in," he added.
(Copyright 2005 by The Associated Press. All Rights Reserved.)