November 4, 2021 – Another weather system will bring light to moderate amounts of precipitation today. More rain is expected for parts of the region on Saturday and then again for the first part of next week.
A weak system is moving through the region with low impacts. Snow levels will be high and generally above pass levels. Gusty winds in the mid 30s mph range over the central and north end of the valley this morning will peak before sunrise and then decrease. Precipitation amounts will range in the valley from a third of an inch near Redding with amounts dropping off in the valley to a tenth of an inch or less as you near Sacramento and to the south.
Foothills and mountains will generally range between a quarter of an inch to three quarters with local higher amounts over Western Shasta county. Amounts will rapidly drop off south of US-50. Dry zonal flow will set up tonight and Friday. Clearing skies and light winds may allow for some patchy fog to develop from around Marysville south Friday morning.
A broad trough will develop over the region Friday and persist through the weekend. Another very weak system will pass through the region Friday night through Saturday night bringing only light amounts of precipitation to parts of the region. Snow levels will continue to be high but may lower to around pass levels along I-80 to bring minimal amounts of snowfall. This system will be weaker than the previous two and any valley precipitation looks to remain north of the Sacramento region but may bring some mountain showers much further south to Tuolumne county Saturday night.
Zonal flow over the Pacific may bring some showers to the northern areas late Sunday with most of the region remaining dry during the day. Continued chance for some overrunning of precipitation will continue Sunday night but models continue to trend drier during this time period.
Extended Discussion (Monday through Thursday)
Models continue to weaken the system next week with the jet bringing the bulk of the precipitation into the Pacific Northwest and much lighter amounts over interior Northern California. WPC and NBM guidance seem to be on the high end of the forecast considering the latest model runs. I have toned down the amounts of precipitation over the area during the Monday through Wednesday time period which has also resulted in a lot less snow for the mountains. The best chance for precipitation looks to be Tuesday night and Wednesday.