textproduct: San Diego

SYNOPSIS

Onshore flow will begin to strengthen today with high temperatures for the coast and valleys cooling a few degrees. A low pressure system moving inland through California will bring more cooling for Tuesday and Wednesday with southwest to west winds for the mountains and deserts strongest for Tuesday afternoon and night with gusts to 40 to 50 mph and isolated gusts to 65 mph. There is also a slight chance for light showers for late Tuesday afternoon through Tuesday night. Thursday will be warmer followed by a cooling trend through next weekend.

SHORT TERM (Today through Wednesday)

A closed low pressure system off the West Coast will move into and through California on Tuesday and Wednesday. Onshore flow will begin to strengthen today with southwest to west winds for the mountains and deserts gusting to 30 to 40 mph for this afternoon and evening. Coastal low clouds will extend into portions of the inland valleys this morning and high temperatures for the coast and valleys will be a few degrees cooler than Sunday, but still a few degrees above average. High temperatures for today will range from the upper 60s near the coast to the mid 70s to lower 80s for the Inland Empire with the lower 90s for the lower deserts.

There will be additional strengthening of the onshore flow on Tuesday with more widespread and stronger southwest to west winds for the mountains and deserts for Tuesday afternoon and night with gusts to 40 to 50 mph and isolated gusts to around 65 mph. The winds will subside some on Wednesday with gusts to 35 to 45 mph and with isolated gusts to 55 mph.

For Tuesday and again on Wednesday, there will be slight cooling of high temperatures near the coast to 4 to 8 degrees of cooling for the mountains and deserts. High temperatures on Wednesday will be around 5 degrees below average for inland areas with high temperatures on Wednesday mostly in the mid 60s to lower 70s for the coast and valleys and in the lower to mid 80s for the lower deserts.

There is a slight chance for light showers for late Tuesday afternoon through Tuesday night as a weakening cold front moves across southwestern California. Models are now keeping the 500 mb 564 DM height just north of the area as the low pressure system moves inland which would usually mean little or no measurable precipitation. The most likely location to receive measurable precipitation in southwestern California would be the San Bernardino County mountains.

LONG TERM (THursday through Sunday)

Thursday will be dry with high temperatures slightly warmer than Wednesday near the coast to around 5 degrees warmer inland with high temperatures mostly within a few degrees of average. High temperatures on Thursday will range from the upper 60s near the coast to the mid to upper 70s for the Inland Empire with the lower deserts in the upper 80s to around 90.

For Friday and Saturday, a low pressure system off the California coast will bring slight cooling of high temperatures on Friday with additional slight cooling on Saturday near the coast to around 5 degrees of cooling for inland areas.

A weak low pressure system could move into southern California some time around next weekend bringing a slight chance of mostly light precipitation.

AVIATION

200930Z...Coast/Valleys...Low clouds based around 1500 feet MSL and tops to 2500 feet will continue to expand in coverage through 15Z, with higher coastal terrain locally obscured in clouds/fog. Scatter out expected by 17Z. Patchy low clouds will gradually develop and expand after 05Z tonight into Tuesday, with similar areal and non- uniform coverage.

Mountains/Deserts...Winds will increase after 22Z today and continue tonight into early Tuesday. Strongest winds will gust 25-35 knots through mountain gaps, desert slopes and locally into deserts, and could produce moderate up/downdrafts in lee of mountains.

Otherwise, mostly clear and VFR conditions are expected today and tonight.

MARINE

Westerly winds will increase Wednesday, generating conditions that could be hazardous for small craft Wednesday into Thursday. Otherwise, no hazardous marine conditions are expected through Friday.

SKYWARN

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

SGX WATCHES/WARNINGS/ADVISORIES

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