October 30, 2020 – Light winds, above average temperatures, and very dry conditions are expected through early next week.
Discussion
Upper high centered over the eastern Pacific is providing warm and dry weather over NorCal. Trough passing over the upper high from the Pacific Northwest will drop southeast over the northern Rockies and Great Basin late this afternoon and tonight.
This will cause a a brief period of increased north and east wind (10 to 15 mph) over the western Sacramento valley and northern Sierra foothills Saturday morning. These winds will diminish during the afternoon.
Upper high will shift east over California and transition into more of ridge early next week, this will keep the warm and dry pattern in place with high temperatures running about 10 degrees above normal with Valley highs from the upper 70’s to low 80’s. Overnight low temperatures will cool to near normal readings in the mid and upper 40’s each night.
Extended discussion (Tuesday through Friday)
Upper ridge will flatten into mid-week, as a low pressure system from the Pacific Northwest tracks across the northern Rockies. Warm and dry conditions will continue over NorCal with precip remaining well north of the area over Oregon. Above normal temps will continue through much of next week in this pattern.
A change in the pattern may begin late Thursday into Friday, as models are in agreement with a low pressure system moving south towards the region. Euro is showing a much deeper solution versus the GFS. Confidence in the details remain low, as there are likely to be numerous run to run model changes over the next week, given this is the first fall storm system of the season. However, a cool down seems quite likely for the end of next week.