An old Salt Lake Valley weather saw says, "If you don't like the weather, wait 10 minutes and it'll change."
But for the impatient, "If you don't like the weather, just cross the street."According to weather experts, few metropolitan communities in the continental United States ever experience the simultaneous, widely varying weather common to the Salt Lake area.
"Absolutely, the weather here varies fantastically from place to place; sometimes from neighborhood to neighborhood," says William J. Alder, meteorologist in charge of the Salt Lake office of the National Weather Service.
He attributes the phenomenon to the surrounding mountains and the Great Salt Lake. Those geographic elements literally play a "pivotal" role on the valley's weather by determining where weather systems go and what they do when they get there.
The elements also explain how 10 people at work on Monday morning could have described 10 different kinds of weekend weather and all been right. Location is everything, local weather experts say.
Weather varies considerably
And the differences from location to location explain how the official weather forecasts and reports can be right - and yet seem so wrong. The weather at the National Weather Service's Salt Lake International Airport station isn't typical of the weather in the rest of the valley.
For example, Alder said Salt Lake City "officially" gets 15.31 inches of precipitation per year, but that figure is based on measurements at the airport station, one of the driest spots in the valley.
Across town, in Olympus Cove, the average rainfall is nearly double that amount, 29.55 inches. Murray sees average annual precipitation of 19.53 inches. In Holladay, it is 22.36 inches.
"Precipitation increases from the northwest to the southeast," Alder said. "It's heaviest along the east bench, but the west bench is also wetter than the valley."
Most winter storms drift across the Great Salt Lake, pivoting anywhere from Davis County to Utah County, and then dump their accumulated moisture while rising over the Wasatch Mountains.
Summer thundershowers, however, tend to roar into town from the southwest, rolling off the Oquirrh Mountains and drenching old Lark, Herriman and Magna while leaving the rest of the valley bathing in sunshine.
Because Big Cottonwood Canyon's twists and turns act as a baffle, it gets less snow than neighboring Little Cottonwood Canyon, which offers storms amuch straighter shot uphill.
Wide range in temperatures
Average temperatures vary as widely as the precipitation, Alder said, noting that one location may be as much as 25 degrees warmer (or colder) than another.
"Within a half-mile radius, you can have a 5-degree temperature difference," he said.
Pumpkins in Riverton, South Jordan and West Jordan are typically nipped by the first fall frost a full two weeks before those anywhere else in the valley; and apricot blossoms in those communities are vulnerable a full two weeks longer in the spring.
Protected by drainage winds, the airport often doesn't register the coldest temperatures in the area. But the airport is usually the first in fog, joined later by communities along the Jordan River.
An occasional exception is Taylorsville, which is just high enough to escape the fog that enshrouds its neighbors.
Bluffdale, South Jordan and other southwest communities are consistently windier than other places. The neighborhoods below the University of Utah are the calmest. A few blocks west, tall buildings funnel and magnify breezes, producing "urban effect" winds in the downtown area.
Downtown buildings and streets also magnify temperatures, making Salt Lake City's business districts one of the hottest spots in the valley. Murray also is subject to the so-called "heat-island effect."
"It's very difficult to make a forecast that applies to everyone," said National Weather Service lead forecaster Ed Carle. "You can have situations where no one is happy with the forecast, even though it's basically accurate."
Carle, too, attributes the unusual weather variations to the mountains and lake.
Because of the terrain, a winter storm from the south may dump on Ogden and Provo and leave the Salt Lake Valley relatively dry.
"Sometimes a weak storm is approaching from the west, and nobody around is getting anything - not Boise or Elko or anyone else," Carle said. "And then we get a big snowstorm out of it."
Many of the basic lessons learned in meteorology classes don't apply, Carle said. "Here, the weather is totally different."