According to an update from NWS San Diego, southern California residents are enjoying one final day of warm and sunny weather before an expected change in conditions arrives. Today's highs are predicted to be in the 70s across the lowlands and deserts, with slightly cooler temperatures in the mid to upper 60s at the coast and 60s in the mountains. However, the forecast suggests a cool down beginning on Saturday, with highs dropping to the mid to upper 60s west of the mountains and in the high desert. In comparison, the lower deserts can anticipate temperatures in the mid to upper 70s and highs in the 50s for mountainous areas.
Some rainfall is expected on Saturday, particularly in the San Bernardino Mountains, where up to one-quarter inch could fall. The lowlands, meanwhile, are forecasted to receive less than one-tenth of an inch. The impending weather conditions can be attributed to an atmospheric river going down from Northern California and into the Southern California region on Saturday. However, it "will weaken considerably," NWS San Diego reports.
While skies were clear this morning, some patches of low clouds and fog were seen along the coast, signaling the start of changes. An onshore flow brings cooler weather and a rebuilding marine layer that will push more low clouds ashore by Saturday morning. The mountains are expected to receive most of the rainfall due to their elevation, although no heavy or prolonged rainfall is foreseen. Additionally, snowfall in the region is not likely an issue for most, as snow levels will remain high, above 9,000 feet on Saturday, and dropping to around 7,000 feet by early Sunday.
Next week, Southern California is in for a "moist pattern with waves of moisture" that will move through the area intermittently. Another moisture surge is forecasted to arrive Monday and could continue through early Wednesday. However, pinpointing precise rainfall amounts and locations for next week's showers presents a challenge. A broad-brush approach indicates the likelihood of "mostly light rainfall Monday into early Wednesday," the National Weather Service discussion notes. By midweek, a transient ridge may bring a return to dry weather, signaling an end to the wetter conditions, though this is subject to change as different model solutions emerge.
For those out on the sea, it's smooth sailing as the Marine forecast indicates no hazardous conditions are expected through Tuesday. For aerial conditions, coastal airports may see impact from low clouds with bases between 700 and 900ft MSL in the early hours. Valley, mountain, and desert regions are expected to maintain clear skies with unrestricted visibility until evening. As always, the community's network of weather spotters is encouraged to report significant weather developments while not requested to activate.
