We've had clouds increasing across northern California today and some scattered showers and thunderstorms have been observed this afternoon. Thunderstorms brought heavy rain and hail to northern Tehama County and Shasta County. The Redding Airport recorded almost an inch of rain between 4 to 5pm Monday afternoon. A Flood Advisory was issued for portions of Tehama and Shasta Counties through 7:30pm tonight due to the heavy rainfall. Temperatures have topped out in the mid to high 60's in the valley and in the 50's in the foothills and mountains today. Winds have been gusty and out of the south. Sustained winds have been up to around 28mph in the valley and we've had gusts up to around 40mph this afternoon.
We'll have a chance for more rain and snow showers tonight, but the main event is expected to arrive early Tuesday and last through Wednesday. Snow levels will start out between 4000' to 5000' at the onset of showers but that will dip into the 3000' to 4000' range on Tuesday. The heaviest showers are projected for Tuesday afternoon through early Wednesday. A Winter Weather Advisory will be in effect down to 3000' in Trinity County from 5am through 5pm Tuesday. 2 to 3 inches of snow are expected to fall there during that time. A Winter Weather Advisory will be in effect from 5am Tuesdqay through 11pm Wednesday in areas above 4000 feet in the Shasta County Mountains and the Western Slopes of the Sierra. 6 inches to a foot of snow is projected to fall in those areas during that time, with some localized peaks seeing up to 18 inches of snow possible from this system. Valley areas are projected to see up to around a half an inch of rain possible in the northern zones, with up to around a quarter of an inch of rain looking possible in the mid valley. The threat of thunderstorms is also ahead for Tuesday and Wednesday afternoons and evenings in the valley. The heavier precipitation is expected to become lighter on Wednesday but snow levels could dip down to around 2000'. Temperatures will start out in the low to mid 40's in the valley on Tuesday and will end up in the mid to high 50's for your Tuesday afternoon. We'll have slightly cooler low temperatures for the start of your Wednesday, but high temperatures will be similar to Tuesdays. Mountain areas will start out in the mid to high 20's over the next couple of mornings and will end up in the high 30's to mid 40's in the afternoons.
Slightly warmer temperatures are on the way for your Thursday, but the potential for showers will linger in the Sierra. We'll be dry with mostly clearing skies in the valley on Thursday. Valley areas will climb back into the low to mid 60's on Thursday and Friday, while mountain areas will climb back into the mid to high 40's.
Another wet system is projected to track across the Pacific Northwest this weekend, and the latest projections have that wet system brushing through northern Calfiornia on Saturday. Showers will be possible for your Saturday forecast and there is a slight chance for some showers on Sunday. The biggest impacts are currently expected in the mountains, but valley areas could also be in for some light to moderate showers during that time. Snow levels are projected to dip to around 3500' this weekend. This system is still several days out and we'll get a much better idea of what to expect for your weekend as that system gets closer to the West Coast.