Marine Weather and Tide Forecast for National City, CA

DISCUSSION
FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES...


UPDATED AVIATION DISCUSSION

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
272330Z...VFR conditions prevail through this evening, with increasing high clouds above 10 kft expected tonight. Intermittent areas of low clouds based around 1500-2000 ft MSL expected Sunday morning from 08-15z, mainly for coastal areas. Very patchy coverage of low clouds for inland valleys. Clouds scatter out by 15-16z with VFR conditions expected through Wednesday afternoon.

MARINE
No hazardous marine conditions are expected through Sunday.

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. Otherwise, surf will become elevated (potential for high surf) on Sunday with the passage of a storm system. More details in the coming days.

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.