The National Weather Service in San Diego has issued a forecast update signaling a decrease in monsoonal moisture today, reducing the likelihood of thunderstorms across the region, especially in the afternoon along Riverside and San Diego County desert slopes, according to the latest synopsis. Meanwhile, remnants of Tropical Storm Juliette are expected to bring scattered showers and potential thunderstorms to parts of southwestern California starting late tonight through Thursday evening, with Riverside County mountains and the San Bernardino Mountains most susceptible to heavier rainfall and even isolated flash flooding.
While thunderstorms today will be less frequent, there is still a slight chance of afternoon showers, particularly in the desert regions as the monsoonal pattern begins to wane; we should see an increase in moisture from Tropical Storm Juliette's aftermath entering the scene, which will elevate the chance of scattered showers and some thunderstorm activity, the National Weather Service San Diego indicates. Thursday is predicted to be cooler, with temperatures across the lower deserts and adjacent mountains dropping significantly, up to 10 to 15 degrees below average, making for a noticeable cool down from recent warmer conditions.
The bulletin further details that conditions will be warm and dry as of Friday, with temperatures expected to climb a few degrees higher than Thursday, marking a gradual return to the region's typical warmth. The Inland Empire and the lower deserts of San Diego and Riverside Counties are forecast to rise in temperatures, with coastal areas remaining comparatively cool. A slight chance of thunderstorms lingers for Friday afternoon, primarily confined to the mountainous regions.
Looking ahead into the weekend, the drying trend should persist, inviting warmer temperatures throughout. The reprieve from monsoonal moistures is short-lived as we see the possibility of its return, early next week could bring about an incremental uptick in thunderstorms mostly for the mountainous regions and deserts, there seems to be a cooldown anticipated with the advent of this increased moisture, the weather service's long-term forecast indicates. For the immediate present, aviation and marine operations might face interruptions; patchy low clouds could affect early flights, and while no significant maritime hazards are projected until Sunday, Thursday could see thunderstorms that may introduce erratic winds and lightning over open waters.
