textproduct: San Diego

SYNOPSIS

Cooling will spread inland as we approach the weekend, with high temperatures on Sunday around 10 to 15 degrees below average for inland areas. Chances for showers will begin increasing on Friday and be highest late Saturday into early Sunday. Chances for rainfall will be around 45 to 55 percent for 0.50 inch or more from the coast to the mountains, with a 35 to 40 percent chance for 1 inches or more. Tides will remain elevated through much of this week with near record water levels resulting in coastal flooding.

DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE

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

Sunny this afternoon, with temperatures near or a little lower than at this time yesterday except in the mountains where temperatures are generally a few degrees higher.

A gradual cooling trend will continue through Thursday under zonal flow aloft ahead of low pressure systems approaching from the west and northwest. Daytime high temperatures will be mostly 5 to 10 degrees below normal. High temperatures on Thursday for the coast and valleys will be mostly in the low to mid 70s, for the mountains in the mid 40s to mid 60s, and for the lower deserts in the low to mid 80s.

Clouds will begin increasing from the west tonight becoming widespread by mid-morning on Wednesday as a closed upper low to our west becomes an open wave as it gets absorbed into the flow on the south side of a stronger low near the coast of Washington state.

The cooling trend will continue into the weekend as extensive troughing develops off the coast south of the parent low near the WA coast. Saturday and Sunday will likely be the coolest days, with high temperatures 10 to 15 degrees below average for inland areas and 15 to 20 degrees below average for the mountains above 6000 feet. High temperatures on Sunday for the coast and valleys will be mostly in the 60s, for the mountains in the mid 30s to mid 50s, and for the lower deserts in the lower to mid 70s.

The low pressure systems will also bring chances for precipitation, starting as early as Friday evening. Rainfall chances will be greatest for Saturday night into Sunday morning. There remains a wide range in rainfall estimates. For the 24 hour period ending Sunday afternoon, chances for rainfall will be around 45 to 55 percent for 0.50 inch or more from the coast to the mountains, with a 35 to 40 percent chance for 1 inches or more. Snow levels will remain high enough so that any accumulations will only occur on at the highest elevations.

Precip will taper off early next Monday and temperatures will begin to rise as the low pressure moves east. High temperatures on Monday and Tuesday will still be a few degrees below normal for inland areas under a ridge of high pressure.

AVIATION

271800Z...VFR conditions prevail into this evening, with increasing high clouds above 10 kft expected tonight. Very patchy and intermittent coastal low clouds based around 1500-1800 ft MSL expected Sunday morning between 09-14z.

MARINE

No hazardous marine conditions are expected through Saturday.

BEACHES

High tides during the late mornings will generate significant coastal flooding this week. Tides will be anywhere from 1.4 to 1.6 feet above astronomical predictions, bringing high tides to 7.7-7.9 feet through Thursday. A Coastal Flood Warning remains in effect through Thursday afternoon and contains more details.

SKYWARN

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

SGX WATCHES/WARNINGS/ADVISORIES

CA...Coastal Flood Warning until 1 PM PDT Thursday for Orange County Coastal Areas-San Diego County Coastal Areas.

PZ...None.