Weather Watch

SLO County weather forecast for the week of July 14

High pressure over Nevada produced hot North County temperatures Sunday, with Paso Robles reaching 105 degrees. Hot indeed! This Nevada high-pressure system should rotate subtropical moisture and clouds from Baja California over the Central Coast today. These mid- to high-level clouds should be thick enough to partially block the sun and cool temperatures a few degrees from their potential maximums. If these clouds don’t move up from the south as expected, maximum temperatures in the North County could reach near-record levels. 

In addition to the clouds, the subtropical moisture is expected to result in warmer overnight minimums, muggy conditions, and a chance for sprinkles and light showers. The monsoon clouds will move northward Tuesday.  Thunderstorms are expected across the Sierra each afternoon this week, with a chance for storms in the coastal mountains, as well. 

The high-pressure ridge is expected to break down later Tuesday, and temperatures will decrease as the marine influence grows.

Maximum temperatures for the opening days of the California Mid-State Fair in Paso Robles are expected to range from the high 80s to low 90s. 

Typical summer weather will continue through this weekend, with night and morning marine low clouds clearing back to the coast during the day.  The high-pressure ridge is then forecast to rebuild next week for triple-digit temperatures at the Mid-State Fair.

When temperatures are hot, avoid strenuous activities in direct sunlight and drink plenty of water. Pay attention to your body. Muscle cramps, dizziness and nausea may be signs of a heat-related illness.    

Today’s surf report

Today’s 4- to 6-foot northwesterly (325-degree, deep-water) sea and swell (with a 5- to

9-second period) will become a 3- to 5-foot northwesterly (300-degree, deep-water) swell (with an 8- to 17-second period)  Tuesday. This swell will remain at this level through Wednesday, decreasing to 2 to 4 feet (with an 8- to 15-second period) Thursday morning. 

Fresh to strong (19- to 31-mph) northwesterly winds will generate a 3- to 5-foot northwesterly (320-degree, deep-water) sea and swell (with a 4- to 13-second period) Thursday afternoon and night.

A 2- to 4-foot northwesterly (310-degree, deep-water) swell (with a 7- to 11-second period) is forecast to develop along the San Luis Obispo County coastline Friday and remain at this height and period through next Monday.

Arriving from the Southern Hemisphere: A 1- to 2-foot Southern Hemisphere (210-degree, deep-water) swell (with a 16- to 18-second period) will arrive at the Central Coast on Thursday and is expected to remain at this height, but with the gradually shorter period, through Friday.

Seawater temperatures

Gale-force northwesterly winds over the weekend produced a great amount of upwelling, which cooled seawater temperatures.

Seawater temperatures are forecast to range from 54 to 56 degrees through today, increasing to 57 and 59 degrees Tuesday, and remaining at this level through Friday.

Seawater will further warm over the weekend.