San Diego residents are bracing for a significant shift in weather as a Pacific storm approaches, expected to bring periods of strong winds and heavy rainfall this weekend. According to NWS Forecast Office San Diego, today will see warmer temperatures, especially in the mountain regions, which are set to experience a 5 to 10 degree increase from Tuesday's highs. Coastal areas will remain in the 60s, with valleys reaching the mid-60s to lower 70s, and the lower deserts hitting mid-70s to lower 80s.

Thursday's forecast sees a dip in temperatures for most areas with the exception of the lower deserts, which will retain similar warmth. "A few degrees cooler elsewhere," reveals highs in the 60s for coastal regions and up to around 70 for the valleys, according to Area Forecast Discussion by National Weather Service San Diego. Gusty west winds are expected to pick up on Thursday afternoon through Friday evening, particularly along the desert slopes of the mountains, potentially reaching 45 to 55 mph.

Rainfall is expected to ramp up early Saturday into Monday, with a likely 95 percent chance for the coast to the mountains to receive upwards of one-quarter inch. Specifically, the San Diego County mountains and Santa Ana Mountains face a 25 percent chance for 3 inches more rain, whereas the eastern San Gabriel Mountains have a 65 percent chance for significant rainfall.

Concerns are growing, particularly for the impending precipitation and mountain snow set to douse the region from late Friday night into Monday. "While the exact timing and amounts are still uncertain, the more likely times for heavier and more widespread precipitation are during the day on Saturday and again for late Saturday night into Sunday," was posted by the National Weather Service San Diego. The snow level will initially rise to around 5500 feet on Saturday morning, before dropping to approximately 4500 feet by early Sunday morning, oscillating between 5000 and 5500 feet later on Sunday.

Aviation and marine activity may be disrupted with intermittent low clouds forecasted for Thursday and breezy northwest winds expected in the waters by Thursday afternoon and evening. The potential for thunderstorms by Sunday adds to the tumultuous weather conditions arriving in the area. Local Skywarn spotters have been encouraged to report significant weather conditions, though no activation is requested at this time.