January 13, 2021 – Occasional light precipitation continues north of I-80 today. Otherwise, dry weather into next week with areas of late night and morning valley fog. Well above average temperatures into next week.
Discussion
After a relative break in precipitation across the north overnight, radar shows the next batch of light warm-advection precipitation spreading into western Shasta County early this morning. Elsewhere, skies remain partly to mostly cloudy as the region remains on the southern edge of the strong AR aimed at the PacNW. Cloud cover remains sufficient to limit much valley fog development. Temperatures are very mild, still in the mid 40s to mid 50s across the Central Valley, around 5-10 degrees milder than 24 hours ago.
Light precipitation may spread as far south as Donner Pass over the northern Sierra this morning, but is only expected across the northern half of the Sacramento Valley at the lower elevations. Precipitation will quickly taper off later this morning and during the afternoon as high pressure begins to build.
Strong ridging returns for the remainder of the week. Late night and morning valley fog is expected to be more extensive late tonight with areas of dense fog possible south of Marysville by around sunrise on Thursday.
High temperatures will be 10-15 degrees above average late this week with record high possible at several locales.
Extended discussion (Sunday through Wednesday)
EPAC upper ridge remains the dominant synoptic feature through the extended forecast period. Short wave trough moves through PacNW into the Great Basin Sunday, but associated precip remains outside of the CWA.
Dry weather expected Sunday through Wednesday with high temperatures 10 to 15 degrees above normal.