Here is this week’s weather forecast by PG&E meteorologist John Lindsey.
Yesterday’s highs reached the low 90s in the North County and coastal valleys. Many of the beaches hit the 80s. Due to the low relative humidity levels and clear skies that the Santa Lucia (offshore) winds brought, Windrose Farm near Creston hit a low of 36 degrees Sunday morning then quickly warmed to 91 degrees by Sunday afternoon.
The area of high pressure responsible for the weekend’s warm temperatures will move toward the east, while a weak upper-level trough will approach from the Pacific. This condition will cause the predominant wind flow to turn onshore today and will allow the marine layer to redevelop along the coastline tonight, producing night and morning low clouds, fog and cooler temperatures through Tuesday. Today’s maximum temperatures along the beaches will reach the 60s, while the coastal valleys will hit the mid-70s. The North County will reach the mid-80s.
A 1,009-millibar low-pressure system will move southward into the Central Coast on Wednesday before cutting off from the jet stream over Southern California on Thursday. This low-pressure system will produce gentle to moderate (8- to 18-mph) southerly winds, rain showers and cooler temperatures Wednesday throughout San Luis Obispo County. Snow levels will lower to around 5,500 and 6,000 feet. Rain fall amounts will only average a few hundreds of an inch in most San Luis Obispo County locations, with a few tenths of an inch of rain in our mountains. Overall, not a lot of rain, but at this point, any precipitation is longed for.
Dry weather will return Thursday. Temperatures on Thursday should warm up a few degrees, but should still remain lower than normal for early/mid-October. Fair and slightly warmer weather is expected Friday as a weak area of high pressure builds across the region. Longer-range models are indicating that cooler weather should return over the following week.
Today’s 3- to 5-foot northwesterly (310-degree deep-water) sea and swell (with a 5- to 14-second period) will become a 5- to 7-foot northwesterly (300-degree deep-water) swell (with an 8- to 12-second period Tuesday morning, increasing to 7 to 9 feet by Tuesday night.
This northwesterly (300-degree deep-water) swell will peak Wednesday at 8 to 10 feet (with an 8- to 11-second period), decreasing to 5 to 7 feet (with a 9- to 11-second period) Thursday. A 3- to 5-foot northwesterly (310-degree deep-water) sea and swell (with a 5- to 10-second period) is forecast along the coastline Friday through Sunday.
Seawater temperatures will range between 55 and 58 degrees through Tuesday, increasing to 56 and 59 degrees Wednesday and will remain at that level through Thursday. Seawater temperatures will start to decrease Friday and will continue to cool through the weekend.
John Lindsey’s Weekly Forecast is special to The Tribune. His Weather Watch column appears in the Local section on Sundays.