A potent shortwave trough is dropping into the backside of the primary upper level trough this evening. Its bringing with it some very cold air (temps projected to drop to -12C at 700 hPa later tonight) and some good dynamics for upward motion. Combined we should see a burst of heavy snow for the Tahoe region, especially since the -12C regime is a good one for snow growth!
But not all the action is happening up in the mountains, as the cold core of the first half of the trough moved across the bay area this evening we found ourselves the convective sweet spot:
Not a huge amount of CAPE, but very easy to trigger! This amounted to a series of heavy downpours across the region:
