April 30, 2020 – Warm weather will continue this week, though high temperatures will gradually trend cooler through the weekend, reaching near normal levels. There is a slight chance of showers north of I-80 late Saturday through Sunday.
Upper level shortwave trough will pass to the north today. Any precipitation will north of the area, though there will be some morning clouds over the northern mountains and northern Sacramento Valley. A cooler airmass is expected, but more heating from the sun should bring slightly warmer for areas affected by the Delta Breeze. Areas to the north and in the mountains should be a little cooler than yesterday.
Friday is expected to see Valley highs in the low 80s as a deeper trough from the Gulf of Alaska approaches. This trough will continue to influence our weather through the weekend. The potential for light rain showers will move into western Shasta County Saturday afternoon, spreading across the county overnight and into western Tehama County. Valley highs will reach the upper 70s to around 80.
Sunday trends a couple degrees cooler, with Valley highs in the mid to upper 70s, near normal levels. There is the possibility for some rain showers north of I-80 through Sunday evening. Some models are hinting at enough instability for potential afternoon convection, but is too uncertain to add to the forecast for the time being.
Extended Discussion (Monday through Thursday)
High pressure begins to build back over Northern California Monday continuing through mid-week. Dry weather, mostly clear skies, and increasing temperatures are expected. High temperatures will be roughly 5 to 15 degrees above average across the area.