Weather Watch

SLO County weather forecast for the week of Feb. 18

Here is this week’s weather forecast by PG&E meteorologist John Lindsey, who is based in San Luis Obispo:

Marine low clouds and fog will clear later this morning. However, a shift to unsettled weather begins today with increasing high-level clouds and gentle southerly winds this afternoon as a cold Gulf of Alaska upper-level low-pressure system moves toward the Central Coast. Today’s maximum temperatures will reach only the high 50s to low 60s.

A significant change in the weather is in store Tuesday as this upper-level low-pressure system moves through San Luis Obispo County with widespread rain showers, a chance of thunderstorms with hail, gusty northwesterly winds and much cooler temperatures.

Snow levels associated with the system are expected to drop to 2,000 feet with some low snow accumulation possible across the higher elevations of the Santa Lucia mountains. Rainfall totals should remain below a quarter of an inch. Nearly a foot of new snow is possible along the higher elevations of the Sierra.

Cool temperatures, partly cloudy skies and moderate gale to fresh gale force (32- to 46-mph) northwesterly winds along the coast are expected Wednesday. The cool and windy weather pattern continues Thursday through Saturday as a series of low-pressure systems moves through Northern California. Except for a few possible showers Thursday, it appears that our part of the state will remain dry for an extended period.

Surf report

An intense 968-millibar storm developed near the Aleutian Islands a few days ago. A 6- to 8-foot northwesterly (295-degree deep-water) swell (with a 20- to 22-second period) from this storm will arrive along our coast today.

Moderate gale- to fresh gale-force (32- to 46-mph) northwesterly winds will develop along the coast Tuesday. These winds, combined with the Aleutian Islands swell, will produce an 8- to 10-foot (310-degree deep-water) sea and swell (with a 7- to 18-second period) later Tuesday.

This northwesterly (310-degree deep-water) sea and swell will further increase to 10 to 12 feet (with a 7- to 16-second period Wednesday, decreasing to 8 to 10 feet (with a 7- to 13-second period) Thursday.

An 8- to 10-foot northwesterly (295-degree deep-water) sea and swell (with a 7- to 15- second period) is expected along our coast Friday through Sunday.

Seawater temperatures

Seawater temperatures will range between 50 and 52 degrees through Sunday.