Warm 4th of July weekend

July 1, 2017 – Warm and mostly dry for the next week. Isolated thunderstorms possible today across Lassen Park.

Discussion

Trough of low pressure is currently along the west coast and will move through the interior during the day and into this evening. The marine layer is currently around 2200 feet deep with decent flow through the Delta that is expected to continue throughout the day. Not a lot of change in temperatures is expected from Friday’s highs and today’s high temperatures. Have left in the slight chance of an isolated thunderstorm over Lassen Park in the afternoon for now but have low confidence in that occurring.

Previous Discussion

A weak shortwave trough is currently moving through northern California. Weather across the region remains dry, but onshore flow through the Carquinez Strait continues to roar as of this writing, and the marine layer at Fort Ord has deepened to 2000 ft. As such, areas near the Delta have cooled off nicely this morning, though the same cant be said for more distant locations like the northern Sacramento Valley, which remains in the upper 70s as of this writing.

Mostly dry weather is expected to continue today across the region as the aforementioned trough passes through. The one exception might be Lassen Park, where just enough forcing may bring a few thunderstorms this afternoon and early evening. High temperatures today are projected to be within a couple of degrees of yesterday, reaching the 90s to lower 100s across the Valley, and 70s to 90s over the mountains.

Temperatures on Sunday will likely be a couple of degrees warmer than today, then some minor cooling is expected on Monday into Independence Day. Onshore flow will likely continue through the Delta into the middle of next week, albeit not as strong as what we’re seeing this morning.

Extended discussion (Wednesday through Saturday)

Dry and warmer weather expected for the latter half of next week as strong high pressure centered over the Southwest extends westward resulting in some synoptic warming across the region along with weakening onshore flow. Warmest readings in the Central Valley will likely once again exceed the century mark in some spots.