Weekend thunderstorm risk returns to San Diego region as monsoon moisture flows in
The San Diego area is entering a pattern that could bring thunderstorms this weekend, with monsoonal moisture returning to the region. Forecasters say thunderstorm development is favored for the mountains and deserts on Friday and Saturday afternoons, while beaches and valleys have at least a slight chance, especially Saturday morning between 5 a.m. and 10 a.m.
What’s driving it
A heat dome centered over the Four Corners region is driving hot, humid air into the Southwest. The clockwise flow around this high-pressure area is dipping south into Baja California and delivering subtropical moisture to Southern California and the desert Southwest. That setup can fuel scattered storms as the atmosphere destabilizes, particularly in the mountain and desert corridors.
Humidity and how it feels
Dew point readings, a key measure of atmospheric moisture, were in the low to mid-60s along the coast by 5 p.m. Friday. In the mountains and deserts, dew points were in the mid to upper 50s. For most people, dew points in the 60s feel muggy, with humidity easing a bit once they fall into the 50s. The coast will likely feel stickier into the evening, while overnight humidity should ease a bit in the higher terrain.
Forecast highs and heat risk
Saturday’s temperatures look notably hotter in the valleys and deserts: coastal areas in the upper 70s to low 80s, valleys and mountains in the low to mid-90s, and desert heat around 110 degrees. The heat remains a concern, with a Heat Advisory in effect for the valleys through Saturday evening and an Extreme Heat Warning for the desert regions. Plan accordingly and stay hydrated, especially during peak heat hours.
Longer-range outlook
After a cooler, drier trend Monday, forecasters say there could be another round of thunderstorms and heat toward the end of August into the Labor Day weekend. If you’re planning outdoor activities, keep an eye on the forecast for sudden storm chances and possible heat spikes.
What this means for you
– Thunderstorms can bring brief heavy rain, gusty winds, and localized clouds. If you’re in the mountains or deserts, monitor weather updates and be prepared for quickly changing conditions.
– Humidity will feel higher near the coast and in coastal valleys; people sensitive to heat should take precautions and limit strenuous activity during peak heat.
– Always heed any watch or warning issued by local weather offices and follow guidance from authorities on heat safety, flash flooding risks, and road conditions.
Summary
A return of monsoonal moisture could spark weekend thunderstorms across Southern California, with the highest chances in the mountains and deserts and a seaside/valley chance on Saturday morning. Expect hot conditions in the deserts, with heat advisories in effect, and keep an eye on the forecast for potential changes through Labor Day weekend. If you’re headed outdoors, plan for early morning activities and stay hydrated.