As the mercury soars across the San Diego region, the National Weather Service (NWS) has declared an Excessive Heat Warning that will persist through Thursday, urging residents to brace for sustained high temperatures. Following a couple of degrees of reprieve, the hot spell is expected to grip various parts of the county, from the lower deserts baking in temperatures between 107 to 113 degrees, to more temperate mid 70s along the coastal areas.
The cooling trend is likely most appreciated near the coolness of the coast and valleys, where temperatures are slated to drop to more typical readings. Meanwhile, the Inland Empire and the Apple and Lucerne Valleys are forecasted to simmer in the 90s to 104 degrees, per the latest NWS advisory. "Slightly cooler than Tuesday for the coast into the valleys with not much change for the mountains and deserts," noted NWS, clearly signaling that any cooling is primarily confined to coastal and valley regions.
Adding a layer of complexity to the heatscape, there's a chance of showers and thunderstorms, particularly this afternoon, with the San Bernardino Mountains and adjoining desert regions on watch. The presence of moisture may also bring about a resumption of the coastal low clouds over the nights this week, a small yet tangible sign of the lingering humidity as the overall atmosphere begins a gradual dry-out process.
According to an Area Forecast Discussion released by NWS, the dry conditions could push dewpoints down as we push toward the weekend. For desert dwellers, the nighttime will offer scant relief from the unabating heat. However, lowering night temperatures might "slowly reduce the daily Heat Risk," as the Excessive Heat Warnings are expected to conclude post-Thursday. However, the promise of any significant respite from the inferno for desert communities remains on the distant horizon.
The conditions seem more benevolent for those taking to the skies or the seas. The NWS assures that no hazardous marine conditions are in sight through Saturday, and flight visibility remains mostly unrestricted, bar the slight possibility of thunderstorms this afternoon, which could prompt skyward navigators to exercise caution due to potential gusty winds and visibility reductions.
