Temperatures will slowly warm under mostly sunny skies through the end of the work week, and light winds will allow some moderate temperature inversions to build into the valleys. High temperatures will climb into the upper 40s Wednesday (about the same highs as we expect up at Lake Tahoe), and could hit 50 by Friday. As we head into Friday, there will be two weather systems competing for our attention, a weak and warm low coming up from the south which will meet a weak cold front coming down from the north. At this time it looks like we will be caught in the middle and won’t get anything from either. Over the weekend a pattern known as an Omega Block sets up in the eastern Pacific, creating a very complicated pattern that could result in a few showers here in western Nevada, but a lot of uncertainty remains with this type of pattern.
We’ve been talking about Lake Effect…it’s a valuable process to understand. It is when a lake of sufficient size (certainly the Great Lakes qualify, but so does Lake Tahoe) affects local snowfall amounts. It does this mainly by providing a point heat source, which in an unstable airmass can generate lift and snowfall in much greater amounts (up to 20 times as much or more in certain instances) than if it wasn’t there. These lakes can also add a little moisture to the local airmass, although that is not as significant contribution as the heat source. It’s a smaller scale (called mesoscale) effect than what the ocean contributes (called synoptic scale).