SLO County getting a break from the rain as El Niño conditions shift. Here’s the forecast

The jet stream or storm track — which has come out of the southwest for much of this winter, guiding storms with above-average rainfall, high snow levels and mild temperatures to the Central Coast in a characteristic El Niño pattern — appears to have shifted to a west-northwesterly trajectory more akin to a neutral phase of the El Niño-Southern Oscillation (ENSO).

This transition is neither La Niña nor El Niño, colloquially known as La Nada or El Nothing, and has been evident since late February, coinciding with the onset of storms originating from the Gulf of Alaska. These storms have brought colder temperatures and consequently lower snow levels.

Remarkably, the Sierra Nevada snowpack, which stood at only 24 percent of average in January, surged to 104 percent by March 4, thanks to the lower snow levels facilitating blizzard conditions. Looking ahead, precipitation is expected to decrease significantly over the next two weeks, accompanied by mild daytime temperatures and cooler nights.

Sunday will start primarily clear with the Santa Lucia (northeasterly) winds, but will become partly to mostly cloudy as a weak cold front dissipates over the Central Coast Sunday night into Monday morning with a few scattered rain showers. Rain will remain below 0.10 of an inch.

In the wake of this cold front, strong to gale-force (25 to 38 mph) northwesterly winds and partly cloudy skies will develop on Monday afternoon.

Another weak cold front from the Gulf of Alaska will create gentle to moderate (8 to 18 mph) variable winds, partly cloudy skies, and a slight chance of a few rain showers on Tuesday.

A high-pressure ridge will build over California, producing a pattern of moderate to fresh (13 to 24 mph) Santa Lucia (northeasterly) winds during the morning. These winds will shift out of the northwest and increase to fresh to strong (19 to 31 mph) levels during the afternoon and evening on Wednesday through next Sunday.

This pattern will produce primarily clear mornings; however, pockets of dense ground fog will develop in the inland and coastal valleys.

Along the coastline, areas of marine low clouds are expected during the afternoon and evening. High temperatures are expected to reach the mid-70s throughout the region by Thursday, with overnight lows dropping to the low 40s in the inland valleys (Paso Robles) and high 40s in the coastal valleys (San Luis Obispo) and along the coastline.

The long-range models indicate dry conditions continuing through the first half of next week.

Surf report

A 6- to 8-foot northwesterly (290-degree deep-water) swell (with an 8- to 18-second period) is forecast on Sunday, becoming a 9- to 11-feet northwesterly (300-degree deep-water) sea and swell (with a 5- to 15-second period) on Monday.

A 6- to 8-foot northwesterly (295-degree deep-water) swell (with an 8- to 14-second period) will develop on Tuesday, decreasing to 5 to 7 feet by Wednesday morning.

Strong to gale-force northwesterly winds off the California coastline will generate a 5- to 7-foot northwesterly (305-degree deep-water) sea and swell (with a 5- to 15-second period) on Wednesday afternoon through Friday.

Seawater temperatures will range between 55 and 5 degrees through Wednesday, decreasing to 54 to 56 degrees on Thursday into 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.