We have peaked in terms of temperatures, and as we head into the weekend we will go from record highs to well below average. A back door low pressure center is very slowly dropping down out of central Canada, and will brush by the northeastern corner of Nevada late Saturday. High temperatures will drop to the mid-60s on Friday (with mostly sunny skies) to the mid-50s on Saturday (with partly cloudy skies) before falling to the mid-40s with a slight chance of a snow shower on Sunday. Unfortunately, the storm system doesn’t have much moisture, and that pathway is rarely known for producing much if any mountain snow.

Courtesy: Eastern Illinois University

Courtesy: Eastern Illinois University

Here’s how landmasses can affect jet streams. Land receives and releases heat from the sun more rapidly than the oceans do, and therefore the vertical convective air currents (called Hadley, Ferrel and Polar Cells) which on a large scale help form somewhat stable weather patterns will have differing strengths over the oceans versus over continents. If your eyes are beginning to glaze over by all of this, suffice it to say that the continents can have an effect on the positioning of large scale persistent weather patterns, which also help determine the strength and position of the jet streams. But in terms of direct interaction between land and jet streams, there’s very little. Since the jet stream is usually found above 25,000’ of elevation, you’d have to get to the Himalayas before the land has any real touch on the jet.

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