The Central Coast experienced the arrival of offshore winds early Friday, which are expected to persist through Saturday. These winds, originating from the northeast, will bring warmer temperatures and lower humidity levels to San Luis Obispo and Santa Barbara Counties on Saturday. While the warm weather might be welcomed by some, the combination of strong winds, dry conditions, and warm temperatures increases the risk of wildfires.
Friday's highs were in the 70s despite the offshore flow because the air left behind by the exiting trough was cool. That airmass will warm on Saturday for the reasons above.
The wind speed will weaken somewhat on Saturday, but they will still be locally gusty,
Technical Details
The offshore winds are driven by a combination of high pressure over the Great Basin and an upper-level low-pressure system moving through Arizona. This creates a strong pressure gradient, forcing air to flow from the northeast towards the coast. As the air descends from the mountains, it compresses and warms, leading to unseasonably warm temperatures.
The ridge flattens Monday as a trough approaches the PacNW. This will weaken high pressure and some marine layer rebound is possible Monday or Tuesday, but not very thick.
A ridge is expected to return to the region from the east midweek to boost high pressure and temperatures, especially in the valleys, where the upper 80s are in my forecast. Some coastal valleys will also return to the 80s. Both are a little above average for this time of year.
Late next week another broad trough looks to push temps down a few degrees next Thursday and Friday.
