Southern Californians enjoyed clear skies and cool mornings, so the National Weather Service in San Diego forecasted a subtle temperature dance for the coming week. Today, the NWS reported high temperatures were slightly below the norm for the lower deserts but hovered around the usual ranges elsewhere. Come Monday, temperatures are expected to tick a few degrees upward, reaching near to marginally above average levels.
Notably, according to the NWS, a dry and warmer trend is on the horizon, particularly over inland areas. Despite this warming trend, low clouds and fog in the marine layer are anticipated to creep back into coastal zones by midweek, although likely in a patchy distribution. The forecast discussion released by the NWS further detailed that "winter in the morning will be followed by spring this afternoon," with coastal highs in the 70s and inland valleys and deserts experiencing low to mid 80s. The high deserts and mountains can expect upper 70s and low 60s to low 70s, respectively.
This temperate episode is courtesy of a stubborn upper low over Arizona and an upper-level ridge slowly making an entrance from the southeast. The NWS anticipates gradual warming through Wednesday, boosting temperatures by 5 to 10 degrees above normal away from the coast, but with the caveat of very weak offshore flow that may keep marine layer low clouds at bay. Should these clouds slip under the building ridge, the region may find itself shrouded in dense fog, though the timing of such remains uncertain.
As the week progresses, a potential trough could flatten the resilient ridge and introduce a shift toward cooler conditions. However, this forecast is far from set in stone; only about 30 percent of ensemble models align with this cooler outcome. "The only given right now is the return of persistent onshore flow, at least for Thursday and Friday, which is when the marine layer is most likely to return," the NWS stated.
For aviators and mariners, the forecast is clear: mostly clear, VFR conditions for flights through Monday morning and no hazardous marine conditions expected through Thursday.
