March 3, 2021 – Dry and mild weather through Friday. Rain and mountain snow chances return over the weekend and early next week.
GEFS show upper low swinging through SoCal today. The system will remain too far south to provide any noticeable change in the weather over NorCal. The only exception will be some increased cloud cover for areas south of interstate 80 and maybe a high mountain isolated shower over Tuolumne county. Upper low will move east over the southern Rockies Thursday with ridge building briefly over northern California.
GEFS then show upper level trough approaching the West Coast Friday with some light showers possibly reaching the Coast Range and Shasta by late afternoon and evening.
High temperatures will generally be 65 to 70 degrees at Valley locations today through Friday.
Trough will move through NorCal Saturday, although ensembles and clusters favor weakening of system as it moves through. At this time system looks to on the lower impact side with 3 to 6 inches of snow at pass level and Valley rainfall amounts ranging from 0.10 to 0.50 inches.
Clusters also are showing trend towards lower QPF amounts. High temperatures will cool into the low 60’s at Valley locations.
Extended discussion (Sunday through Wednesday)
Pacific frontal system approaches the CWA Sunday and weakens as it moves inland Sunday night.
Models indicate some light associated precipitation possible mainly over northern portions of the forecast area.
Series of short waves progged to move through over the first half of next week.
This will result in periods of unsettled weather with below normal temperatures, gusty wind, lower elevation rain, and mountain snow.