Dry spell and windy weather ahead this week across SLO County; no rain expected

Late fall and winter dry spells are not uncommon, and we’re heading into one. The question is, will it persist? La Niña tends to prolong them as the Ridiculously Resilient Ridge (RRR) can remain stubbornly anchored along the West Coast.

High pressure over the western United States will continue to produce gentle to moderate (8 to 18 mph) Santa Lucia (northeasterly) winds on Sunday morning.

This offshore flow will keep the marine layer out to sea. The winds will shift out of the northwest on Sunday afternoon into Tuesday. This onshore flow will allow the marine layer with pockets of fog and mist to develop in the coastal regions overnight.

Along the marine layer, variable amounts of high-level clouds will continue to stream over the Central Coast.

Overnight lows will drop to the low-30s in the inland valleys (Paso Robles) and high-30s in the coastal valleys (San Luis Obispo), and the low 40s along the beaches. High temperatures will range between the high-50s away from the ocean and the low-60s in the coastal regions.

Fresh to strong (19 to 31 mph) north to northeasterly winds are forecast on Tuesday night through Thursday, keeping the marine layer out to sea. However, a weak cold front is expected to wash out over the Central Coast on Wednesday night into Thursday morning with increasing high-level clouds.

The long-range models indicate warmer weather developing on Christmas Eve through Christmas Day, with the inland and coastal valleys and the beaches reaching into the low-70s. There is no indication of any rain through the first week of January.

Surf report

A 2- to 4-foot west-northwesterly (285-degree, deep-water) swell (with an 8- to 14-second period) is expected along our coastline on Sunday through Tuesday.

A 3- to 5-foot northwesterly (310-degree, deep-water) sea and swell (with a 4- to 11-second period) will develop along our coastline on Wednesday through Friday.

An intense mid-latitude cyclone will generate a 12- to 14-foot west-northwesterly (285-degree, deep-water) swell (with a 17- to 19-second period) along our coastline on Dec. 30 and Dec. 31.

Seawater temperatures will range between 56 and 58 degrees through Friday.

This week’s temperatures

LOWS AND HIGHS, PASO ROBLES

LOWS AND HIGHS, SAN LUIS OBISPO AND COASTAL VALLEYS

John Lindsey is a retired PG&E marine meteorologist. Email him at JohnLindseyLosOsos@gmail.com or follow him on Twitter @PGE_John.