May 10, 2018 – Warm and dry weather continues. Slight cooling returns early next week along with a chance of showers and thunderstorms over the mountains.
Some high clouds overhead associated with weak short-waves moving through the broad trough over NorCal. Current temperatures are a bit cooler compared to 24 hours ago and range from the mid 30s in the mountain valleys to the lower 60s across milder portions of the Central Valley.
Onshore gradients have slackened considerably since Wednesday, so not expecting any stratus to make it inland into the Sacramento region this morning. Temperatures will be up slightly for most areas today with little or no synoptic warming.
Stronger wave moves down from the PacNW on Friday eventually forming a closed low over the Great Basin by late in the day. A few showers will be possible Friday afternoon in the Sierra south of Lake Tahoe ahead of the strong short-wave.
However, the bigger impact will be gusty northerly winds that develop Friday as a strong barrier jet sets up along the west side of the Sacramento Valley and continues Friday night. MFR-SAC gradient forecast to peak around 11 mbs with gusts around 40 mph possible during the day in the valley and continuing Friday night over the western foothills.
The closed low is forecast to remain centered near where the Utah/Nevada/Idaho borders meet through the weekend. Temperatures will remain a little above average with a chance of late day showers and thunderstorms over the Sierra Nevada.
Extended discussion (Monday through Thursday)
Next week a blocking pattern is expected across the region, with an upper low centered over the Great Basin and an upper level over the Pacific Northwest. This setup will bring cooler, near normal temperatures along with mountain showers and afternoon/evening thunderstorms. A Pacific upper low approaches mid week, keeping this general pattern going through the rest of the week, and bringing below normal temperatures. The core of the low moving is currently expected to move inland late Thursday into Friday, though there are hints of lingering mountain showers potentially into the weekend.