San Diegans looking to escape the summer heat might find surprise relief this week, according to the National Weather Service San Diego. Coastal areas can expect highs between 69 and 75 degrees today, followed by "a few degrees warmer" temperatures on Wednesday, which will remain "slightly below average," as per a recent publication from the NWS San Diego website.
In a more detailed outlook, the Area Forecast Discussion states that the marine layer, currently "around 3500 feet deep," is responsible for "below average high temperatures," which will continue through Saturday. This anomalistic weather pattern results in temperatures 10 to 15 degrees below the norm for many inland valleys and higher mountain elevations. Spreading into portions of the valleys late each night, night and morning coastal low clouds are expected.
For those living inland, there's good news: high temperatures ranging from around 70 near the coast to the 80s for the Inland Empire are forecasted for today. The marine layer's depth will lessen to "around 2000 to 2500 feet by Thursday," per the NWS, leading to less extensive coverage by coastal low clouds. An associated moderate warming for the coast and valleys of around 5 degrees is anticipated for Wednesday and Thursday.
Looking ahead, "a weak low pressure system" will introduce another twist, cooling high temperatures by around 5 degrees for coastal and valley areas from Friday into Saturday, according to the area forecast discussion. But as high pressure strengthens to the east, the coming Sunday through the middle of next week will bring a gradual warming trend. The NWS anticipates high temperatures for Wednesday of next week, which will be "around average for the coast and valleys and around 5 degrees above average for the deserts."
Aviation forecasts indicate that low clouds may affect visibility in some inland valleys and foothills this morning, with potential for "patchy -DZ" and minor reductions in visibility. However, conditions are expected to clear by late morning, providing VFR conditions across all terminals by the afternoon. Mariners should also note that northwest winds could reach 20 kts near San Clemente Island from Wednesday to Friday.
