Will SLO County get more rain? Here’s what’s next in the weather forecast

A series of storms that swept across the Central Coast last week brought gusty winds and much-needed rainfall.

From Monday through Thursday, these storms delivered 4.24 inches of rain at the San Luis Obispo County Regional Airport, 3.76 inches at the Paso Robles Municipal Airport and 3.66 inches at the Santa Maria Public Airport.

For comparison, average February rainfall is 4.86 inches in San Luis Obispo, 2.54 inches in Paso Robles and 2.8 inches in Santa Maria.

Los Osos, which is typically one of the drier coastal locations, saw an impressive burst of rain when a low-pressure system moved through on February 10 and 11.

My Baywood Park tipping bucket rain gauge recorded 1.07 inches during that event, while many other areas picked up only trace amounts. Altogether, my Davis Vantage Pro 2 weather station and standard rain gauge have measured 5.7 inches of rain so far this month.

These totals are certainly welcome, especially as forecasts point toward another extended dry stretch, with little or no rain expected through the first week of March.

March, however, is often one of the stormiest months along the corridor between San Luis Obispo and Santa Barbara counties. As winter transitions to spring, the Pacific jet stream typically remains strong enough to steer energetic systems into the Central Coast. Its shifting position can intensify winds and frontal boundaries.

At the same time, colder air aloft combined with increasing spring sunshine enhances atmospheric instability, leading to heavier showers, thunderstorms and gusty winds. Local terrain, including the Santa Lucia and Santa Ynez Mountains, can further amplify rainfall and wind, making March systems especially dynamic.

A striking example occurred in March 1995, when an atmospheric river stalled over the region and produced extraordinary rainfall.

The rain gauge at the Diablo Canyon nuclear power plant measured 8.5 inches during just 24 hours, and some locations in the Santa Lucia Mountains reportedly received more than 20 inches of rain. Flooding affected many communities, with Cambria among the hardest hit as Santa Rosa Creek overflowed its banks.

Looking ahead, a 1,027-millibar high-pressure system will build northward and position itself offshore, diverting the main storm track into Northern California, Oregon and Washington. As a result, our area is expected to remain mostly dry into early March, aside from a slight chance of light rain from Tuesday evening into Wednesday morning.

Persistent northwesterly winds from Tuesday through Thursday will allow the marine layer to redevelop along the coastline, bringing areas of low clouds, patches of fog and mist during the overnight and morning, and dense ground fog in the inland valleys.

High temperatures will range from the low 60s at the beaches to the low 70s in coastal valleys such as San Luis Obispo, and the upper 60s in inland valleys including Paso Robles through Thursday.

By Friday into the weekend, moderate to fresh (13 to 24 mph) Santa Lucia (northeasterly/offshore) winds will promote mostly clear skies and a warming trend, with many Central Coast communities reaching the mid-70s.

Overall, predominantly dry conditions are expected to continue through the second week of March.

Surf report

A 3- to 5-foot westerly (270-degree, deep water) swell (with an 8- to 14-second period) will develop on Sunday, increasing to 4- to 6-feet with the same period on Monday through Wednesday morning.

A 4- to 6-foot northwesterly (285-degree, deep water) sea and swell (with a 5- to 15-second period) will develop on Wednesday afternoon through Thursday, decreasing to 3- to 5-feet on Friday into the weekend.

Seawater temperatures will range between 58 and 60 degrees through Friday.

On this date in weather history (Feb. 22)

1990: A winter storm produced heavy snow and high winds across the southwestern United States. Snowfall totals ranged up to 18 inches at Lake Arrowhead, California, and Ashford, Arizona. High winds in New Mexico gusted to 100 mph east of Albuquerque. (David Ludlum)

2006: A morning cold front produced 0.09 inches of rain at the Diablo Canyon Ocean Lab. An upper-level trough that crossed California produced isolated rain showers with numerous rainbows throughout our area and thunderstorms over the central valley with frequent lightning strikes.

2008: The relaxation of the northeasterly (offshore) winds and clear skies produced cold temperatures in the morning with many of our areas reaching below the freezing point.

2010: A very strong and fast-moving, low-pressure center (972 millibars) developed about 400 miles to the west of Northern California. The associated cold front intensified as it moved toward the Central California coastline. Southeasterly winds at the Diablo Canyon nuclear power plant sustained at 40 mph with gusts up to 50 mph, and surface pressure quickly dropped to 999 millibars at 10 a.m.

2019: The westerly swell at the Diablo Canyon waverider buoy peaked at 17.2 feet with an 18-second period at 3 p.m. The Santa Lucia Escarpment waverider buoy about 45 miles to the southwest of Diablo Canyon reached 25 feet with an 18-second period at 4 p.m., while the Cape San Martin NOAA buoy peaked at 24 feet.

This week’s temperatures

LOWS AND HIGHS, PASO ROBLES

SUNDAY: 36, 65

MONDAY: 39, 68

TUESDAY: 48, 67

WEDNESDAY: 50, 70

THURSDAY: 48, 71

FRIDAY: 47, 74

SATURDAY: 47, 75

SUNDAY: 49, 74

LOWS AND HIGHS, SAN LUIS OBISPO AND COASTAL VALLEYS

SUNDAY: 45, 66

MONDAY: 49, 70

TUESDAY: 55, 68

WEDNESDAY: 56, 71

THURSDAY: 57, 72

FRIDAY: 55, 76

SATURDAY: 56, 77

SUNDAY: 57, 75

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