As temperatures dip, the National Weather Service (NWS) issues a reminder for residents, particularly in the eastern Inland Empire and valleys of San Diego County, to remain vigilant against frosty conditions over the next couple of nights. To safeguard plants, pipes, and pets, the NWS advises taking necessary precautions in light of the chilly weather ahead.
The current weather pattern is characterized by an upper low near the Four Corners, set to move east out of the region. Simultaneously, a high-pressure ridge off the West Coast will build into California by Sunday. While weak waves moving through the ridge will moderate temperature increases, the nights are expected to be particularly cold in wind-sheltered valleys, along the coast, and in the lower deserts. Despite high soil moisture levels following recent rains, areas approaching freezing temperatures may experience significant frost.
The NWS’s National Blend of Models (NBM) highlights the greatest probability of temperatures reaching 32 degrees or less into the area from Temecula to Perris, with up to a 65% probability tonight. The Model Output Statistics (MOS), including the ENS/GFS/NAM, consistently show below-freezing temperatures tonight and for the following two nights. Consequently, a frost advisory has been issued for the valleys, which may need to be extended into Sunday night, even with a slight increase in 850 MB temperatures.