The National Weather Service (NWS) San Diego predicts a cooling trend for the city heading into the weekend. Temperatures will drop 10-20 degrees below normal by Friday while the marine layer deepens, bringing the possibility of drizzle in coastal and inland areas early in the week, according to an NWS San Diego forecast
Monday's highs are expected to remain steady with coastal areas seeing temperatures between 63 to 68 degrees, although the inland valleys will experience a slight dip to 68 to 78 degrees, this subtle shift precedes a more pronounced cooling period as we stride into the latter half of the week. A marine layer, which has already begun to blanket the coastal basin, is set to thicken and could lead to patchy morning drizzle from Tuesday through Thursday, especially to the west of the mountains, according to the National Weather Service.
As the week progresses, a closed low is expected to develop off the Californian coast, moving inland by Thursday and phasing with another trough from the Pacific Northwest to sustain cooler temperatures and generate stronger winds. Through this period, the marine layer is anticipated to peak at around 5000 ft, potentially causing morning drizzle to evolve into more substantial showers come Thursday.
Differing models suggest varying outcomes for the region late in the week, with "about 40% of the ensemble members maintain a large low progressing south into CA/NV". In contrast, others predict a drier trajectory, reports the NWS San Diego. San Diegans should prepare for a higher chance of precipitation Thursday night through early Saturday, as the chance of showers increases to 15-40% for all areas except the lower deserts. Meanwhile, aviation interests might note that coastal and valley fog, with bases around 1000-1500 feet MSL, will likely persist through the week and could impact visibility on the approach to the terrain.
The immediate forecast for San Diego today calls for cloudy skies with a high near 66 degrees and light winds transitioning southwest, as per the detailed outlook on the NWS's website. The patchy drizzle is likely after 11 pm, with the week progressing under the aegis of mostly cloudy skies and occasional sunny breaks anticipated by the weekend.
