Nov. 17, 2018 – Just about everyone will be happy to hear that rain is finally headed for California – with significant accumulations likely by Thanksgiving, especially in NorCal. The first system or two early this week might end up being “sacrificial” in the sense that they will largely fall apart as they move into the very dry and stable antecedent airmass. But subsequent storms later in the week, especially from Wednesday through Saturday, could bring widespread (and possibly even locally heavy) precipitation to the northern half of the state. Rain will likely also fall in SoCal, though it will probably be lighter in magnitude. By Friday, though, there’s an excellent chance that just about the entire state will have received enough moisture and onshore winds to fully clear the air of smoke, and help to extinguish the remaining flames.
In NorCal, the rains this week should (finally!) be “season-ending” from a wildfire perspective. In the Sierra Nevada, significant snow will fall above pass level–probably giving a boost to early-season snow totals that are currently right around zero. There is some concern that precipitation near the recent burn scars in NorCal (especially the Camp Fire, Carr Fire, and Delta Fire) could be heavy enough to induce debris flows or flooding, especially in areas that have burned very recently in the past two weeks). That will largely depend on how far south a potentially significant atmospheric river event sags next weekend. It’s possible that the heaviest totals will remain up in Oregon or along the far North Coast, but if you do live near or downstream of these fire zones if would be wise to pay attention to the forecasts this week (and, unfortunately, for the winter to come). In SoCal, I don’t think widespread precipitation will be heavy enough to cause major problems in the recent burn scars, but there’s still a slight chance that could change.