This certainly won’t be the first Memorial Day Weekend with some less than ideal outdoor weather (it seems to happen every year), but even with that low bar, it’s likely to be one of the least “Unofficial Start of the Summer-ish” types of forecasts that we’ve had for a few years.
Cool and showers weather will continue through the Weekend, with a chance of showers and/or thunderstorms right on through. Temperatures will begin to drop on Saturday into the upper 60s and then down to the 50s on Sunday. Precipitation-wise, snow levels will remain above the major passes until late Saturday night, after which they will drop below 7,000’. Total accumulations will likely be light, probably not more than a few inches in the passes above Lake Tahoe, with perhaps twice that down toward Mammoth, but it could be enough to cause some travel issues for those unprepared.
Temperatures slowly rebound on Memorial Day Monday (mid-60s) and should make the 70s through the rest of the week, with only a slight chance of mainly afternoon showers.