With temperatures slightly cooling from the recent heat, the National Weather Service's (NWS) San Diego office indicates a continuation of the trend, noting that it is slightly cooler than Wednesday for the lower deserts and around 4 to 8 degrees cooler elsewhere for Thursday, and a few degrees cooler than Thursday for coastal areas and around 5 degrees cooler inland for Friday. San Diego County can expect the mid to upper 70s near the coast to the 90s for the inland valleys, while Orange County will stay around 80 near the coast to the lower to mid-90s inland.
Despite this dip, Ramona set a daily record high on August 20th with 102 degrees, surpassing the 1982 record of 100 degrees, sharing this feat in a post from NWS SanDiego. As the marine layer deepens into the week, a "coastal eddy will bring deepening of the marine layer into Friday with coastal low clouds extending into portions of the inland valleys on Friday morning", reports the National Weather Service, with the marine layer increasing in depth from 1200 to 1500 feet to 2000 to 2500 feet by Friday morning.
The cooling shift is attributed to "a developing large low pressure system along the West Coast will bring a cooling trend through Friday and Saturday with Saturday high temperatures as much as 10 to 15 degrees below average for the mountains, inland valleys, and high desert," detailed in the National Weather Service Area Forecast Discussion. Additionally, there is a slight risk of isolated thunderstorms for the southeastern region of San Diego County, with any forecasted thunderstorms not expected to impact TAF sites.
Heading into the weekend, the NWS anticipates that following the cooling into Saturday, a warming trend is expected for Sunday through Tuesday, with high temperatures for the mountains, inland valleys, and high desert going from 10 to 15 degrees below average on Saturday to a few degrees above average on Tuesday. There is also a possibility of monsoonal moisture returning mid-next week. However, chances for measurable rainfall remain slight through the end of next week, yet the probability for afternoon thunder slightly increases to around 10 percent for Tuesday and Wednesday.
Regarding advisories, mariners have a smooth sailing forecast ahead as "No hazardous marine conditions are expected through Friday," according to the National Weather Service. While the community watches the skies, no Skywarn activation requests are made, but weather spotters are encouraged to remain vigilant in reporting significant weather conditions.
