August 23, 2018 – Cooler and dry weather expected through the week. Areas of smoke and haze will continue, especially near wildfires.
Discussion
A weak shortwave ridge is currently traversing across Northern California, and is sandwiched between upper troughs over the northern Rockies and the NE Pacific Ocean. An extensive area of marine stratus is persisting along the coast with the marine layer running around 3000 ft deep at Fort Ord.
A healthy onshore flow continues through the Delta, and it wouldn’t be surprising for a bit of mist and stratus to reach the interior near Sacramento by sunrise. The aforentioned NE Pacific trough will move through the Pacific Northwest today into Friday, bringing renewed cooling across the region. Valley high temperatures will likely be in the 80s to around 90 degrees today and Friday, roughly 5 to 10 degrees cooler than normal. Highs over the mountains will be in the 60s to 80s.
A reinforcing shortwave trough dropping into the region on Sunday could bring even cooler temperatures. Areas of smoke of haze will continue, especially near wildfires.
Extended Discussion (Monday through Thursday)
Model differences continue to exist in extended forecast period with depth and timing of short waves troughs. Main theme is for continued dry weather with below normal temperatures and periods of increased onshore flow.