Weather Watch

SLO County weather forecast for the week of June 30

Here is this week’s weather forecast by PG&E meteorologist John Lindsey.

This morning’s marine low clouds and fog are expected to be slow to clear from the beaches. Consequently, maximum temperatures along the coastline will range from the low to high 60s. Farther inland, a high-pressure ridge will peak in strength and produce triple-digit temperatures in many North County locations and the low 80s in the coastal valleys. 

However, the warm-up will be short-lived as a 1,006-millibar surface low pressure system moves over the Central Coast with North County and coastal valley temperatures decrease by 5 degrees Tuesday. This low-pressure system will also produce a persistent marine layer along the coastline with some of the beaches remaining mostly overcast throughout the day. The cooling trend will continue into Wednesday.

The area of low pressure responsible for persistent marine layer will move toward Nevada later Wednesday. This condition will produce increasing northwesterly winds and a greater amount of clearing along the coastline Thursday into Saturday.  

The marine low clouds are expected to roll in after Fourth of July fireworks shows. However, if they redevelop earlier than anticipated, the cloud ceiling should remain above 500 feet of altitude, which will allow for good viewing of the displays. 

It appears that temperatures across the North County will warm to above normal temperatures early next week. When temperatures are unusually high, avoid strenuous activities in hot, 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 5- to 7-foot northwesterly (305-degree, deep-water) swell (with an 8- to 12-second period) will decrease to 4 to 6 feet with the same period Tuesday. This swell will further lower to 3 to 5 feet (with an 8- to 11-second period) by Wednesday morning. 

Fresh to strong (19- to 31-mph) afternoon northwesterly winds will generate a 4- to 6-foot northwesterly (320-degree, deep-water) sea and swell (with a 4- to 8-second period) Wednesday afternoon and will remain at this height and period through Saturday. 

Arriving from the Southern Hemisphere: A 1- to 2-foot Southern Hemisphere (185-degree, deep-water) swell (with an 18- to 20-second period) will arrive Thursday, peaking at 1 to 3 feet (with a 15- to 17-second period) Friday. 

Seawater temperatures

Seawater temperatures will range from 52 to 54 degrees through Saturday.