The National Weather Service San Diego has issued a Flood Watch for several regions, including the Apple and Lucerne Valleys, Coachella Valley, and the Riverside and San Bernardino County mountains, as the remnants of Tropical Storm Mario bring showers and possibly heavy thunderstorms to the area. The heaviest rain is expected in the mountains and deserts this afternoon and evening, with rainfall potentially reaching two inches per hour in isolated areas. San Diegans should brace for a damp day with high temperatures ranging in the mid-70s to around 80 near the coast, toasting up to the mid-90s for the lower deserts, notably below the seasonal average, especially for the elevated regions of San Bernardino and Riverside Counties, per the NWS San Diego.
Travelers and locals alike are advised to remain vigilant as the weather conditions could swiftly evolve; the mountains and deserts, from 5 AM PDT today until 2 AM PDT Friday, will be the prime zones facing a threat of flooding, which could be catalyzed by bands of thunderstorms tracking persistently over similar terrains, as highlighted by the San Diego Area Forecast Discussion. High temperature forecasts stretch from the 80s for the Inland Empire to the sizzling 90s for the lower desert regions, as much as 10 to 15 degrees chillier than what’s typical for the higher mountains in San Bernardino and Riverside Counties, providing an unexpected respite from the customary scorcher of a September day.
The deluge is anticipated to recede slightly tonight, leading into Friday, with showers and thunderstorms becoming less likely, hugging mainly to the relief of the mountains and deserts by Friday afternoon; the downward trend in precipitation is matched by a gradual upturn in temperature over the weekend. Saturday’s forecasts are showing a mild climate reprieve with coastal highs fluttering in the mid to upper 70s while the valleys and deserts notch a few degrees warmer than Friday’s figures, gently nudging toward the norm for this time of year but still tipping a few degrees shy of average for the loftier mountainous reaches…