textproduct: San Diego

SYNOPSIS

High temperatures peak on Saturday, before a slight cooling for early next week. Locally gusty offshore winds will continue through Saturday for mountains and foothills. Warmer conditions return for the middle to end of next week, with additional periods of Santa Ana winds.

DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE

SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES...

Visible satellite was showing extremely clear skies across the area as of 11 AM. Gusty north to northeast winds were occurring across the mountain foothills locally into the valleys. Wind gusts this morning peaked at 35 to 45 mph, with a few localized gusts in the 50 to 55 mph range. A similar uptick in winds are expected tonight into Saturday morning, with strongest winds most likely in foothills and canyons prone to easterly winds. Winds will slowly diminish into Saturday afternoon, with a brief return to onshore flow expected for Sunday and Monday.

Highs temperatures will peak on Saturday and are expected to be a few degrees warmer than today. Highs today and tomorrow are forecast to be 15 to 20 degrees above average for inland valleys and about 10 degrees above average for the coast, deserts, and mountains. Cooler conditions are expected on Sunday for the coast and valleys, with cooler conditions reaching further inland on Monday. Even with the cooling, highs Sunday and Monday will remain above average for this time of year. We may also see a return in low clouds and fog along the coast early next week with the break in prevailing offshore flow.

By Tuesday, all global ensemble guidance indicates a ridge of high pressure will rebuild over the US West Coast. The upper level ridge is expected to remain in place, and potentially strengthen, through the end of next week. This will bring another period of warm and dry weather to Southern California. NBM chances for highs exceeding 85 degrees are currently highest on Wednesday at 60 to 80 percent for the valleys and inland Orange County. Chances go down slightly Thursday but remain 50 to 60 percent. Chances of exceeding 80 degrees is near 100 percent on Wednesday for the valleys and inland Orange County and 70 to 80 percent for Thursday. The absence of marine layer influence for the middle to end of the week will allow coastal high temperatures to rise as well. A surface high is expected to form over the Great Basin for the middle to end of the week, bringing another period of offshore winds. Most of the latest ensemble guidance is indicating the offshore winds will be similar in strength to today and Saturday's. There does still remains some spread between ensembles in the strength of the winds, with 10 percent of the guidance showing the potential for a moderate to locally strong Santa Ana wind event.

AVIATION

301830Z...Mostly clear and VFR conditions today and tonight. Areas of northeast wind gusts 25-35 kts will continue in foothills and below mountain passes into adjacent valleys. Localized low level wind shear is possible today downwind of mountain passes when winds aren't reaching down to the surface.

MARINE

No hazardous marine conditions are expected through Wednesday.

SKYWARN

Skywarn activation is not requested. However weather spotters are encouraged to report significant weather conditions.

SGX WATCHES/WARNINGS/ADVISORIES

CA...None. PZ...None.