High pressure will keep the weather warm over San Diego County this weekend as the smoke layer caused by the Valley Fire slowly thins, the National Weather Service said Saturday.
Marine clouds and fog should remain patchy and confined to coastal areas, forecasters said. Cooler weather is expected for later next week as a low-pressure trough arrives over the West Coast.
While radar does show some lessening of the smoky sky caused by last week's Valley Fire, satellite imagery showed the smoke continuing in place Saturday morning, the NWS said.
"Satellite imagery does show less smoke over the southern half of San Diego County, but there is more dense smoke aloft moving in from the north, so really everywhere today looks to continue with hazy sunshine due to the smoke aloft and this will continue through at least Sunday," forecasters said.
Saturday's air quality was determined to be unhealthy for sensitive groups, according to a radar by Purple Air. The region's air is expected to impact sensitive groups through at least Wednesday.
The county recommends impacted communities, such as the elderly, children and individuals with a compromised respiratory system, stay indoors as much as possible, limit outdoor exercise, close all windows and to run an air purifier.
High temperatures along the coast Saturday will be 76 to 81 degrees with overnight lows of 57 to 64, the NWS said. Inland highs will be 84 to 89 with overnight lows of 54 to 60.
Western valley highs will be 87 to 92, with 92 to 97 in the foothills. Mountain highs will be 87-94 with overnight lows of 53 to 62. Desert highs will be 103 to 108 with overnight lows of 69 to 76.
"No big weather changes are on tap for Southern California over the next few days,'' forecasters said. "A shallow marine layer may produce some patchy night and morning clouds and fog along the coast, but daytime temperatures will remain elevated. The longer nights, dry air, and light wind will create a bigger spread in overnight lows through Monday."
For next week, a ridge will strengthen for even warmer weather through midweek, the weather service said. No strong winds were forecast.
"Bigger changes are in the works for later next week as the ridge, which has been with us much of this month, is replaced by a longwave trough along the West Coast," forecasters said. "A gradual cooling trend will set in by next Thursday as onshore flow strengthens and the marine layer deepens. Look for the cooler weather to stick with us at least into the following week."