textproduct: San Diego

SYNOPSIS

Santa Ana winds expected through Saturday, with the strongest and most widespread winds today. Additionally, moderate to major HeatRisk is expected for coastal areas. Cooler conditions will spread inland Sunday, with greater cooling, increase in westerly winds, and chance of showers for the middle of next week.

DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE

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

Gusty winds are being observed across Southern California, with the strongest winds being observed on mountain foothills and below passes and canyons. Top 3 wind gusts over the past 48 hours were Buckman Springs with a gust of 82 mph, a 80 mph gust in Hellhole Canyon, and a 78 mph gust in Sill Hill. Over the past 12 hours the top 3 wind gusts are Hellhole Canyon, Sill Hill, and Banning with a gust of 73 mph. A more comprehensive peak wind gust report is headlined on our weather.gov/sandiego homepage. Winds have peaked across the area and are expected to begin to weaken through this evening into Saturday. That being said, winds will remain elevated into Saturday especially for places prone to east winds. Peak wind gusts for Saturday will be 35 to 55 mph, with gusts to 60 mph confined to wind prone locations.

Elevated to near-critical fire weather conditions will continue through Saturday, though relative humidity values will increase on Saturday. Some influx of moisture from the south will keep relative humidity values above 15% through the remainder of the event. In fact, there is a slight chance of light showers for southern San Diego County Saturday morning, though there is an even lower chance (5-10%) for any wetting rainfall.

High temperatures will peak today, gradually decreasing through the weekend into early next week. By Tuesday, most locations are expected to be running a few degrees below average near the coast to up to 10 degrees below average for inland locations. With those cooling conditions we're monitoring for the potential for elevated westerly winds and precipitation. The most likely time for precipitation looks to be Wednesday and Thursday, but some locations further north have the potential to see precipitation as early as Tuesday afternoon or evening. Precipitation will likely remain light to moderate due to lack of any notable moisture source, though model guidance has trended wetter since yesterday. There is still some disagreement on precipitation amounts. We'll have more details in the coming days.

AVIATION

161800Z...Northeast to east winds strongest through and below foothills gusting 30-50 kts, locally 60 kts. This will cause MOD-STG downdrafts in lee (south and west) of mountains, along with areas of LLWS. Winds will gradually weaken after 00Z, but continue with a slightly more easterly direction. More weakening expected Saturday after 11Z.

Otherwise...SCT high clouds and VFR conditions expected through this evening, with increasing clouds above 10 kft especially near Mexico.

MARINE

Isolated northeast gusts could exceed 20 knots today into early Saturday. Otherwise, no hazardous marine conditions are expected through Tuesday.

BEACHES

A south swell increasing Sunday and Monday will bring elevated surf of 3 to 5 feet with sets to 7 feet for Monday and Tuesday. While surf and rip currents will be elevated, high tides will not be particularly high, and the threat of coastal flooding is minimal.

SKYWARN

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

SGX WATCHES/WARNINGS/ADVISORIES

CA...Heat Advisory until 8 PM PDT Saturday for Orange County Coastal Areas-Orange County Inland Areas-San Diego County Coastal Areas.

High Wind Warning until 8 PM PDT Saturday for San Bernardino and Riverside County Valleys-The Inland Empire-San Diego County Valleys.

High Wind Warning until 8 PM PDT this evening for San Bernardino County Mountains.

High Wind Warning until midnight PDT Saturday night for Riverside County Mountains-San Diego County Mountains-San Gorgonio Pass near Banning.

High Wind Warning until noon PDT Saturday for Santa Ana Mountains and Foothills.

Wind Advisory until noon PDT Saturday for Orange County Inland Areas.

PZ...None.