What will weather be like for Thanksgiving? See SLO County forecast

Last week brought much-needed rain, but this week will turn dry, with crisp, autumn nights and mornings followed by mild afternoons through Thanksgiving Day.

This November has been remarkable for the number of upper-level low-pressure systems affecting the region, including one cut-off low that was separated from the storm track that produced copious amounts of rainfall in Southern California as it lingered over that region.

In fact, this month saw the greatest number of upper lows that created rain I’ve even seen during my 34 years of forecasting along the Central Coast.

Because these systems lacked the typical gale-force southerly winds and well-defined cold fronts associated with surface lows, rainfall totals ended up higher than usual in the eastern and southern portions of the region, which typically receive less precipitation.

So far this month, the Santa Barbara Municipal Airport has recorded 8.9 inches of rain, shattering the previous November record of 6.9 inches set in 1965. Santa Maria Airport has measured 4.2 inches — just shy of its November record of 4.7 inches from 1965.

Farther north, San Luis Obispo County Regional Airport has received 3.7 inches, well below the 7.8-inch record from 1965, while Paso Robles stands at 3 inches, approaching its 1965 benchmark of 5.2 inches.

Interestingly, despite the strong start to the 1965 rainy season, which set the milestone for a wet November, it ultimately ended below average; Cal Poly recorded just 15.2 inches for the year.

Jan Null, a well-known meteorologist with Golden Gate Weather, has explored the correlation between July to November rainfall and full-season July to June totals.

He observed notable differences: Northern California exhibited a moderate to strong correlation, whereas the Central Coast displayed only a weak relationship.

During La Niña years — which we are currently experiencing — the correlation is even weaker.

High pressure over California will produce a pattern of fresh to strong (19 to 31 mph) and at times gusty Santa Lucia (northeasterly) winds during the night and morning, decreasing and shifting out of the northwest during the afternoon will continue through Thanksgiving Day.

This condition will produce mostly clear skies and dry conditions, aside from pockets of overnight and morning dense fog and stratus clouds on the ridgelines of the Santa Lucia and coastal mountains.

Low temperatures will range from the high 30s in the inland valleys (Paso Robles) to the low 40 in the coastal valleys (San Luis Obispo) and along the beaches, with highs reaching into the high 60s to low 70s throughout the region.

A dry cold front will produce strong to gale-force (25 to 38 mph) northwesterly winds on Friday into next Saturday, producing cooler daytime highs and areas of low marine clouds in the coastal regions.

Beyond that, a chance of unsettled weather is anticipated during the first week of December.

Surf report

A 6- to 8-foot northwesterly (300-degree, deep water) sea and swell (with a 5- to 15-second period) is forecast along our coastline through Tuesday, decreasing to 3 to 5 feet (with a 7- to 18-second period on Wednesday into Thursday.

Gale-force northwesterly winds along the California coastline will generate a 9- to 11-foot northwesterly (310-degree, deep water) sea and swell (with a 5- to 15-second period) on Friday into next Saturday.

Seawater temperatures will range between 59 and 62 degrees through Thursday, decreasing on Friday through next Saturday as Increasing amounts of upwelling develops.

On this date in weather history (Nov. 23)

1943: Northern New Hampshire was in the grips of a record snowstorm, which left a total of 55 inches at Berlin, and 56 inches at Randolph. The 56-inch total at Randolph established a 24-hour snowfall record for the state. In Maine, Middle Dam received a record 35 inches of snow in 24 hours. (David Ludlum)

1988: Low pressure crossing the Great Basin brought wintry weather to parts of the western United States. Up to 1 foot of snow blanketed Yellowstone Park and winds gusted to 70 mph at Casper, Wyoming, and reached 95 mph near Reno, Nevada. Up to 7 inches of rain was reported in the Grass Valley and Nevada City area of California. Paradise, California, was soaked with 5.37 inches of rain in 24 hours. (The National Weather Summary) (Storm Data)

2015: Santa Lucia winds helped to create near record-breaking high temperatures throughout the coastal regions of San Luis Obispo County and northern Santa Barbara County with plenty of mid- to high-80s temperature readings.

2017: For the second day in a row, Paso Robles and San Luis Obispo broke heat records, and Santa Maria tied a record. San Luis Obispo hit 91 degrees Wednesday, surpassing the old record of 87 degrees in 2002. The high in Paso Robles was 88 degrees, smashing the old record by nine degrees of 79 set in 2015. Santa Maria tied its 1933 record of 89 degrees.

This week’s temperatures

LOWS AND HIGHS, PASO ROBLES

SUNDAY: 40, 66

MONDAY: 39, 67

TUESDAY: 40, 65

WEDNESDAY: 38, 68

THURSDAY: 41, 71

FRIDAY: 40, 67

SATURDAY: 42, 68

SUNDAY: 42, 72

LOWS AND HIGHS, SAN LUIS OBISPO AND COASTAL VALLEYS

SUNDAY: 44, 65

MONDAY: 45, 65

TUESDAY: 46, 65

WEDNESDAY: 46, 68

THURSDAY: 47, 72

FRIDAY: 48, 68

SATURDAY: 48, 67

SUNDAY: 50, 73

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