April 27, 2017 – Dry weather through much of next week with breezy north winds Thursday and Friday.
Last remaining batch of showers is slowly shifting east from the northern Sierra along I-80 and will likely be east of the region by sunrise. Satellite imagery shows plenty of mid and high clouds spilling over the eastern Pacific into NorCal, and the IR fog product shows low clouds along the eastern edge of the Central Valley banked up along the foothills and onto the west slopes of the northern Sierra.
Current temperatures are a little cooler across most of the area compared to 24 hours ago and generally range from the mid 30s to mid 40s in the mountains with upper 40s to mid 50s elsewhere.
Weather systems will be deflected well to the north of the region over the next several days as ridging builds along the west coast. The result will be dry and milder weather for interior NorCal along with periods of breezy north winds for the Central Valley, especially Friday. Temperatures are expected to return to around average, or above, by the weekend.
Extended discussion (Monday through Thursday)
First half of next week looks warm and dry under upper level high pressure ridge along the west coast. Daytime highs start out around 10 degrees above normal on Monday then continue to warm to almost 15 degrees above normal by Wednesday. Extended models indicating north breezy winds at times as weak weather systems pass to the north. Surface gradients become fairly tight at times across the north state but northwest flow aloft provides poor upper level support so these winds should not become a major factor except in the role of warming temperatures and drying. Should see lighter winds next Wednesday as upper high pressure ridge centers over the west coast. Upper ridge shifts inland by next Thursday bringing a return to a more onshore flow and slightly cooler temperatures although daytime highs are still expected to remain well above normal. GFS and ECMWF both show a shortwave trough passage through the Pacific Northwest and Norcal late next Thursday and Friday and bring a slight precipitation threat to the north state. Still too early to jump on this yet and would not be surprised to see this feature shift northward in subsequent model runs.