LOS ANNGELES (CNS) - A cooling trend will get underway in the Southland today, sending temperatures between 5 and 10 degrees below normal, National Weather Service forecasters said.  

The cooling results from a deep marine layer and a trough over the region keeping cool air to the east and west, said National Weather Service meteorologist Dave Bruno.

The weather will feel “almost fall-like -- nice if you don't like the heat,'' he said, noting that valley temperatures will begin dipping to the 70s today. Autumn begins on Sept. 22.

The NWS forecast partly cloudy skies in L.A. County today and highs of 74 at LAX, in Avalon and on Mount Wilson; 78 in Long Beach; 79 in downtown L.A. and Burbank; 81 in Pasadena, San Gabriel and Saugus; 85 in Lancaster; and 86 in Palmdale and Woodland Hills. In contrast, a high of 84 was forecast in Downtown Tuesday and 94 in Woodland Hills. Temperatures will begin inching their way back up on Saturday.

Sunny skies were forecast in Orange County today, along with highs of 69 in Laguna Beach; 70 in San Clemente; 74 in Newport Beach; 77 in Mission Viejo; 80 in Irvine; 81 in Anaheim; and 82 inn Fullerton and Yorba Linda. Irange County temperatures will remain about the same through at least Tuesday, according to an NWS forecast.