textproduct: San Diego

SYNOPSIS

Weak onshore flow will bring slight cooling to the coast today and a possible brief return of low clouds and locally dense fog near the coast late tonight into early Thursday. For Thursday and Friday, high pressure aloft and weak offshore flow will bring warming with high temperatures on Friday as much as 25 to 30 degrees above average for portions of the inland valleys and lower coastal slopes of the mountains. For Saturday through Monday, high pressure aloft will weaken and lower-level flow will become onshore and strengthen. This will spreading cooling and higher coastal humidity inland with high temperatures for next Monday around 5 degrees above average.

SHORT TERM (Today through Friday)

Satellite imagery shows some high clouds spreading across southern California early this morning with no coastal low clouds as of 1 AM. Weak onshore will bring slight cooling of high temperatures to coastal areas today and a possible brief return of low clouds and locally dense fog near the coast late tonight into Thursday morning.

For Thursday and Friday, high pressure aloft will strengthen and lower-level flow will go weakly offshore. High temperautres for the coast, valleys, and mountains will warm around 5 degrees on Thursday and around another 5 degrees for most areas on Friday. With the warming, high temperatures on Friday will be as much as 25 to 30 degrees above average for portions of the inland valleys and coastal slopes of the mountains.

High temperatures on Friday will range from the mid to upper 70s near the coast to around 90 for the inland valleys with the mid to upper 90s for the lower deserts. There could be widespread record high temperatures on Friday, except possibly at the coast. NBM probabilities of exceeding the existing high temperature records on Friday exceed 90 percent for Chino, Ontario, Riverside, and Ramona.

LONG TERM (Saturday through Tuesday)

High pressure aloft will weaken and onshore flow will return and strengthen across southern California for the weekend into early next week as a low pressure system over the eastern Pacific weakens as it moves toward the West Coast and inland into California. NBM daily chances for measurable precipitation are highest for next Monday and Tuesday, but remain below 10 percent.

AVIATION

251030Z...VFR conditions today and tonight for most of the region with decreasing high clouds. Except: isolated fog vcnty KSAN through 15Z, not likely to impact the airport. Better chance (20-30%) of low clouds and fog to impact coastal airports with bases 300-500 feet MSL and vis 1-5SM after 02Z into Thursday.

MARINE

No hazardous marine conditions expected through Sunday.

SKYWARN

Skywarn activation is not requested. However weather spotters are encouraged to report significant weather conditions.

SGX WATCHES/WARNINGS/ADVISORIES

CA...None. PZ...None.