Early fall rainfall in NorCal; typically warm, dry, and occasionally windy weather persists in SoCal
A seasonably weak cold front is currently dragging itself over far NorCal this afternoon, bringing with it gusty winds, cooler air aloft, and some light rainfall. Ths cold front will hold together just long enough to bring some light/very light precipitation to parts of the Bay Area and Sacramento Valley overnight and into the early morning hours. There is not enough instability present behind the cold front to initiate any significant convective activity, so only fair-weather cumulus development is expected behind the front on Monday afternoon. Some subtropical moisture may get pulled into SoCal from a decaying tropical storm in the Eastern Pacific, but at this point no rainfall is expected to occur. A slightly deeper and colder system, though containing decidedly less moisture than the current one, will renew shower chances over NorCal later this week, and this time there may be enough cold air aloft to initiate a few isolated thunderstorms as 850 mb temps drop into the 0 to 3 C degree range and surface temps stay up near 70F. No large storms are on the horizon, and although SoCal may experience some cooler weather and locally strong offshore winds as a result of these fall-like systems passing by to the north, measurable rainfall is very unlikely over the next 2 weeks south of the Bay Area.