A cold shot of air will move through the Great Basin over the first half of the Labor Day weekend. Saturday will still be a bit breezy (although not as bad as Friday), and high temperatures will drop to the upper 60s to near 70 degrees. Skies should clear off, setting us up for the first frost of the season Sunday morning. Look for Sunday lows in the valleys to drop into the 30s in most areas outside of the urban areas, and with clear skies ground (and tomato) temperatures will almost surely fall below the freezing mark.

As the weekend progresses, temperatures will rebound under sunny skies. Sunday’s high will rise to the upper 70s, will reach the mid-80s on Labor Day Monday, and will climb into the low 90s by the end of the work week.

Speaking of winds, Lee Barker asks: “We have been wondering why the wind we experience during the day drops off to almost dead calm after 8:00 in the evening when we are all hoping for a nice cooling evening breeze when we go to sleep. Can you enlighten us? I live in Carson City by the way in case that is relevant.”

Come get your enlightenment. Typically at night the wind will die down, and that happens for a couple of reasons. The first is you start to lose the forces that create the afternoon wind to begin with. Typically our afternoon Washoe Zephyr wind is caused by the afternoon sun heating up the eastern hills in creating thermal lift which draws in a westerly breeze. Once the sun goes down you start to lose that driving mechanism. You will also start to pool in some cooler air into the valleys which creates a slight temperature inversion and calm winds underneath the cap. This will occur at different times depending on your exact location in the valley. It sounds like Lee lives in an area where that gets set up pretty quickly.