Lake Effect

Hi there,

I've been wondering about the effect the lower level of the Utah lakes during the drought, particularly the Great Salt Lake, has had on the precipitation levels throughout the winters?

I know that I hear often how you talk about how significant the lake effect is when it comes to snow totals, so I guess I'm just wondering if having lower lake levels has perpetuated the drought? And conversely, would higher than normal lake levels increase water in the mountains East of any lake, thus adding to increased potential for flooding?

Thanks for your time!

Andrew H.

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Lake effect snow is one of the unique features to our weather here in SLC. Like the lake effect of the Great Lakes in the east, ours works the same way. Lake levels fluctuate as moisture from surrounding land and mountains drain into the Great Salt Lake.

Here's the thing, there's a few answers to this and hopefully we can make it not so confusing. Not all snow storms are lake effect storms and not all storms that pass through will produce lake effect snow so it's tough to say how much of an impact the lake makes on snow totals in SLC. To study this, you'd have to analyze lake levels along with particular lake effect snow (LES) events.

The areal coverage is important in producing the lake effect snow. If levels of the GSL drop as they would in a drought year and the areal coverage became less, this could in theory reduce the amount of LES. But again, not all of our snow storms are from the lake, but it could reduce the snow totals in those storms that do contain LES.

Have lower levels in GSL perpetuated the drought? Well since not all our snow and rain comes from the GSL probably not. Could it lower snow totals in SLC? Only if we're measuring snow totals that are lake driven.

Would higher lake levels lead to more snow? In theory, perhaps. If the lake was bigger (like the Great Lakes) you would have higher snow totals in those storms that produce LES. Not all storms produce LES. Would it increase the potential for flooding? Maybe. You'd have to have huge amounts of snow totals and then that melting of the snow at a quick rate to increase the flood threat.

The key to this is the areal coverage of the lake and remembering that not all storms have lake effect snow. We need the correct wind direction and temperature difference from the lake to the air.

Also, if the lake was dropping all the time and becoming shallower, you'd also run into warmer temperatures of the lake! Just like if you had a tiny puddle and put a ton of sunshine into it, it would heat up quickly. Already, our lake is very warm because it is very shallow. If you made it even less deep, it would be even warmer! This would have some type of effect on the snow as well. So drops in lake level and changes in temperature would both effect snow that is lake driven.

Answered by KSL Meteorologist Dina Freedman.