San Diegans are in for a notable uptick in temperatures this week, according to the National Weather Service (NWS) San Diego. For Saturday, weather reports indicated a warming trend across the region, with temperatures expected to rise around 5-10 degrees higher than Friday's figures, and by Wednesday, highs are forecasted to climb 10-15 degrees above normal. In particular, Coachella Valley is facing a scorching week ahead, with a 10% chance of the mercury hitting 100 degrees or more on Wednesday and rising to a 40-60% chance by Thursday.
Breezy conditions have also been forecasted for today, with "weak northerly to northeasterly winds through this afternoon," as per NWS San Diego, though these gusts, potentially reaching 25 to 35 mph, especially in the mountains and parts of the Inland Empire and Coachella Valley, should ease by the late afternoon. But as the upper-level ridge from the west moves in by Sunday, and temperatures inland will continue an upward march well above normal highs, the coastal areas will feel a bit spared, with only slightly higher-than-usual temperatures. Meanwhile, offshore gradients are set to strengthen through the morning as surface high pressure settles over the Great Basin, aided by northerly 850 mb winds of 15-20 kt.
Tuesday brings subtle height rises under mostly zonal flow, which is expected to bring minor inland warming. In contrast, ensembles show "excellent agreement" regarding the upper ridge amplifying across the Southwest US Wednesday and Thursday, according to the detailed Area Forecast Discussion by the National Weather Service San Diego. Inland Empire residents, in particular, might face extreme heat, with a 50-80% chance of high temperatures of 90 degrees or more.
Looking forward, the forecast becomes less clear later in the week with diverging ensemble forecasts concerning an upper trough off the West Coast, with possibilities ranging from a rapid cooling scenario to an extended hot period; "these differences continue into Saturday," reports NWS San Diego. In aviation, less than a 10% chance of adverse conditions due to low marine clouds is forecasted for today and tomorrow morning, being mainly near the coastal areas of southern San Diego County, though gusty north to northeast winds are expected to impact mountains and deserts through early Saturday evening.
Marine conditions are expected to be smooth sailing, and no hazardous conditions are anticipated through Thursday. Skywarn activation is not currently needed.
