SLO County weather forecast for the week of Sept. 6: Record heat is on the way

Moderate to fresh (13 to 24 mph) Santa Lucia (northeasterly) winds will develop during the morning, shifting out of the northwest and increasing to moderate to fresh (13 to 24 mph) levels in the afternoon and evening. These winds should keep the marine layer to a minimum. However, areas of haze and smoke from wildfires will continue to cover Central Valley and other parts of the state and reduce air quality and visibility.

High pressure is expected to continue strengthening on Sunday into Labor Day, leading to record-breaking temperatures away from the coastline. The Paso Robles Airport is forecast to hit 116 degrees on Sunday and 115 on Monday.



If these daily high temperatures develop, they will be record-breaking. The record highs at the Paso Robles Airport are as follows: Sunday 107 degree set in 2008 and Monday 108 set all the way back in 1957. The record all-time high in Paso Robles is 115 degrees set back on July 20, 1960 and again on September 2, 2017

The high temperatures in many coastal valleys will reach triple-digit level with San Luis Obispo expected to hit 103 degrees on Sunday. The record high in San Luis Obispo on Sunday is 101 degrees set back in 2004.

Along the beaches and a few of the coastal valleys, the warmest part of the day should occur during the late morning due to compressional heating of the Santa Lucia winds, before the northwesterly winds bring cooler air from the Pacific during the afternoon. High temperatures along most of the beaches will range between the high 70s and mid-80s over this period.

A low-pressure system will move southward into the Great Basin on Monday, followed by an area of high pressure that will produce increasing northwesterly winds later Monday into Tuesday. These winds combined with weakening high pressure over the Central Coast will produce cooler temperatures on Tuesday. Decreasing northwesterly winds on Wednesday and Thursday will allow the marine the layer to deepen and move inland for cooler weather in the coastal regions.



Note: North to northeasterly winds are forecast in the Sierra Nevada and northern Sacramento Valley by Tuesday. These winds coupled with the preceding heat event will lead to drier fuel levels, bringing elevated fire potential; conditions will be monitored closely for any changes.

Surf report

Today’s 4- to 6-foot northwesterly (305-degree, deep-water) sea and swell (with a 5- to 12-second period) will remain at this height but (with a 5- to 8-second period) through Wednesday.

Arriving from the Southern Hemisphere: A 1-foot Southern Hemisphere (215-degree, deep-water) swell (with a 20- to 22-second period) is forecast to arrive along our coastline on Sunday, increasing to 1 to 2 feet (with an 18- to 20-second period) by Monday. This Southern Hemisphere swell is expected to peak at 1 to 3 feet (with a 16- to 18- second period) on Tuesday.

This week’s temperatures

LOWS AND HIGHS, PASO ROBLES

LOWS AND HIGHS, SAN LUIS OBISPO AND COASTAL VALLEYS

PG&E safety tip

Are you ready for a heat wave? Please visit www.pge.com for heat related safety tips.

John Lindsey’s is PG&E’s Diablo Canyon marine meteorologist and a media relations representative. Email him at pgeweather@pge.com or follow him on Twitter @PGE_John.