textproduct: San Diego

SYNOPSIS

Warm and dry conditions with periods of Santa Ana winds expected this week. The peak of the heat is expected to be mid-week. Patchy low clouds could develop overnight into Monday morning near the coast.

DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE

SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES...

Clear skies are prevailing across the area this afternoon. For tonight into Monday morning there is a 10 to 20 percent chance of patchy low clouds and dense fog developing along the coast, with slightly higher chances of dense fog developing over the coastal waters. Mostly clear skies will prevail from Monday afternoon through the middle of the week due to periods of weak to moderate Santa Ana winds.

A persistent surface high pressure over the Great Basin will remain in place through Saturday. This will bring weak to locally moderate Santa Ana winds to the area. With no upper level support, the strongest winds will remain confined to coastal mountain slopes, foothills, and below passes. The strongest winds are expected on Tuesday with gusts 25 to 45 mph. A secondary peak in winds is expected on Friday. The airmass getting pushed into Southern California from the Great Basin will be on the drier side, with minimum afternoon relative humidity for inland areas falling to 10 to 20% each afternoon through Friday, bringing periods of elevated fire weather conditions.

An upper level ridge over the East Pacific will strengthen over the US West Coast through Tuesday, bringing an uptick in high temperatures. High temperatures on Tuesday will be 15 to 20 degrees above average. Widespread highs in the low to mid 80s are forecast across the inland coastal areas into the valleys as well as the low deserts. Weaker Santa Ana winds and a weakening in the upper level ridge will allow for minor cooling on Wednesday and Thursday mainly for coastal areas. The secondary uptick in Santa Ana winds on Friday is expected to bring additional warming to areas west of the mountains with high temperatures expected to run up to 20 degrees above average for inland areas. Nights and mornings will remain cool, especially in the wind-sheltered areas, minimizing any heat impacts. A few degrees of cooling is expected into next weekend as weak onshore flow returns, but temperatures will continue to run above average.

AVIATION

072100Z...Clear skies and VFR prevail region-wide. After 01z this evening, 10-20% chance for very patchy fog developing within 5 miles of the coast with very patchy VIS reductions. Offshore E/NE winds gusting 25-35 kts to pick up through mountain passes and Santa Ana mountain coastal slopes after 13z Mon, clearing out any leftover fog. VFR once again Monday afternoon.

MARINE

Tonight, 20-30% chance of patchy dense fog with visibility 1 nautical mile or less through early Monday before sunrise.

SKYWARN

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

SGX WATCHES/WARNINGS/ADVISORIES

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