Posted May 28, 2007, 12:49 PM.

Although the impact is felt more at the coast, where entire days can be completely socked in (something that happens only once in a while inland), the relentless onshore flow helps keep our spring temperatures down, especially in places like Fallbrook, Temecula, Murrieta, Menifee and Riverside. Less so in Hemet, San Jacinto, Sun City and Lake Elsinore, which are along the Elsinore convergence zone.

At least inland we have sunshine in the late morning and afternoon during most of this period.

Coastal eddies typically generate the marine layer and onshore flow flings it inland. Sometimes marine layer is the product of low pressure systems. The depth of the marine layer is dependent on where the inversion layer is (warmer air is above the inversion layer, cooler below).

For example, this week, morning low clouds are predicted every day in Fallbrook, Temecula, Murrieta, and Riverside, most days in Lake Elsinore, Sun City and Menifee, and some days in Hemet.

Sometimes June Gloom will last into July in inland areas of Southern California, but typically heat and high pressure catches up, and when they do, the marine layer will mostly exit for the season.