Here is this week’s weather forecast by PG&E meteorologist John Lindsey.
The high-pressure ridge that brought 100-plus-degree temperatures to the North County this past week will weaken. Cooler conditions are expected through the workweek as a series of weather systems brush Northern California resulting in a deeper and more extensive marine layer and increasing northwesterly (onshore) winds.
This morning’s marine low clouds and fog will burn off from the coastal valleys later in the morning and from the beaches by this afternoon. Today’s high temperatures will hit the high 90s in the North County and high 70s in the coastal valleys. The beaches will be in the 60s, except the southwesterly facing beaches of Cayucos, Avila Beach and Shell Beach, which will reach the 70s.
By Tuesday, southwesterly flow at the mid and upper levels of the atmosphere will draw in some subtropical moisture across San Luis Obispo County, with a slight chance for afternoon thunderstorms across higher elevations of the southern Sierra.
The remnants of Hurricane Odile will give plenty of mid to high-level clouds and will produce a chance of sprinkles/light rain showers across San Luis Obispo County late in the week. This subtropical moisture will also produce mild overnight temperatures and muggy conditions during the day. A few long-range models are advertising a week cold front approaching the Central Coast later Friday into Saturday, which could enhance the amount of possible precipitation. At this time, details are unclear.
Arriving from the Northwest: Increasing northwesterly winds will generate 3- to 5-footnorthwesterly (320-degree, deep-water) seas (with a 4- to 6-second period) through Tuesday. A 4- to 6-foot northwesterly (305-degree, deep-water) sea and swell (with a 5- to
15-second period) will arrive Wednesday and will continue at this height but with a gradually shorter period through Friday.
Arriving from the South: A 1- to 2-foot Southern Hemisphere (210-degree, deep-water) swell (with a 22- to 24-second period) will arrive along the coast today, building to 2 to 3 feet (with an 18- to 20-second period) Tuesday and Wednesday. These long-period waves can produce rip currents, which are the leading surf hazard for beachgoers. Don’t fight the current. Swim out of the current in a direction following the shoreline. When out of the current, swim toward shore.
Seawater temperatures: Seawater temperatures are forecast to range from 57 and 60 degrees through Friday.