SLO County weather forecast for the week of Sept. 19

Here is this week’s weather forecast by PG&E meteorologist John Lindsey.

A change in the weather pattern from Sunday’s hot and dry conditions will occur Monday into Tuesday as a weak, upper-level low pressure system moves through California. Although moisture is limited with this system, thunderstorms may develop during the afternoon hours into Wednesday in the Sierra Nevada and Tehachapi Mountains as moisture is drawn northward.

Otherwise, that condition will allow the marine layer to redevelop and deepen along the coastline and surge inland with night and morning low clouds and fog. It could also bring pockets of mist and drizzle, along with gentle to moderate southwesterly winds along the shoreline and lower temperatures.

Many of the beaches may remain overcast throughout the day into Wednesday. Monday’s high temperatures will range from high 90s in the North County to the low 80s in the coastal valleys. The beaches will range between the low to mid-60s.

High pressure will redevelop Wednesday into Saturday for gale-force northwesterly winds along the coastline. These winds will mix out the marine layer, leaving behind clear skies and a moderate warming trend away from the shoreline. At this time, there is still no rain in sight for the Central Coast.

Surf report

Monday’s 4- to 6-foot northwesterly (300-degree, deep-water) swell (with an 8- to 14-second period) will remain at that height and period into Tuesday.

Gale-force northwesterly winds along the California coastline will generate a 5- to 7-foot northwesterly (310-degree, deep-water) sea and swell (with a 5- to 11-second period) Wednesday, increasing to 6 to 8 feet (with a 5- to 8-second period) Thursday. This northwesterly sea and swell will decrease to 4 to 6 feet (with a 5- to 9-second period) Friday and will remain at that height and period through next Monday.

A 1- to 3-foot Southern Hemisphere (195-degree, deep-water) swell (with an 18- to 20-second period) will arrive along our coastline Thursday into Friday.

Seawater temperatures

Seawater temperatures will range between 56 and 61 degrees through Tuesday. Seawater temperatures will decrease Wednesday into Friday.

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This week’s PG&E safety tip: PG&E can help you prune your trees near power lines safely. We can create a safe distance between your trees and power lines. You can then hire a contractor for any additional work.

Call 800-743-5000 to request this “make safe” service or a temporary service shut-off so you can prune near your service drop safely.

This story was originally published September 18, 2016 at 6:35 PM with the headline "SLO County weather forecast for the week of Sept. 19."