July 18, 2017 – Warm and dry through the week. Breezy winds possible the next several days.
Red Flag Warning until 8 PM this evening for Burney Basin and Northeast Plateau in Shasta County Including Northwest Lassen NF north of Lassen NP-Northern Sierra Foothills from 1000 to 3000 Ft. Includes portions of Shasta-Trinity and Butte Units- Northern Sierra Including Lassen NP and Plumas and Lassen NF/S West of the Sierra Crest (West of Evans Peak-Grizzly Peak- Beckworth Peak).
Clear skies across interior NorCal early this morning with stratus now showing up along the coast. Some elevated smoke from the Detwiller Fire is working its way northward through the Motherlode. A combination of slight synoptic cooling along with a return of onshore flow is resulting in cooler temperatures across the region early this morning. Most sites are running around 3-8 degrees cooler compared to 24 hours ago.
While not as hot as the past several days, warm and dry conditions will continue across the region through mid-week. Another short- wave will clip the northern part of the state today and will lead to another afternoon of breezy southwest winds across the higher terrain. Red flag warnings remain in effect into this evening.
Less breezy conditions are expected Wednesday and Thursday. Another warm-up is expected to begin Friday as high pressure once again strengthens across NorCal.
Extended discussion (Saturday through Tuesday)
A weak ridge will be building in for the weekend. That is going to bring dry weather along with warmer temperatures. The good news is highs don’t look as warm as what we saw this last weekend but they will still be running 5-10 degrees above average. Highs will be near 100 in the south Valley on Saturday with 100-105 in the north Valley. Sunday highs will be just a few degrees higher and will be the warmest day of the extended period.
An upper level low over British Columbia with set up a trough along the west coast late Sunday into Monday. This will bring cooling temperatures into next week and we should see them return to average by Tuesday. Despite the trough pattern, things are looking to stay dry. Models are indicating the return of some monsoon moisture after Tuesday but it is still pretty far out at this point and confidence in low.