Marine Weather and Tide Forecast for San Clemente, CA

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

Update: The ECMWF still has temperatures being the warmest for tomorrow, and a consensus of the high res models (HRRR) has locations within the Coachella Valley at possibly reaching 115F degrees for the max temp. There could also be some locations within the Imperial Valley maxing out at 100+. Low clouds will begin to fill back in and surge inland throughout the evening, with low enough bases that there will likely be some restrictions to visibilities due to mist, as well as areas of patchy fog, especially for some of the inland valleys in the more wind-sheltered areas. The marine layer will be quite thin compared to recent days and will likely clear out for most locations by 10 AM tomorrow morning. It will remain on the thinner side over the next couple of days.

Ensembles have begin to differ more in recent model runs with respect to max temperatures over the course of the next week, with the GFES showing temperatures remaining on the warmer side, and the ECS revealing that there will be a gradual cooldown. This will depend on the subtropical ridge to the south and where it establishes itself over the course of the next few days. Otherwise, there has been move agreement with ensembles for the following weekend, showing that there will be a longwave trough transitioning over the region, which will allow for temperatures to begin to cool back off again.

(Previous discussion submitted at 133 PM):

Visible satellite at 1 PM was showing patchy low clouds lingering along the coast. Low clouds and fog will move back inland this evening, but are not expected to make it past the western valleys tonight. Low clouds are expected to remain persistent each night and morning for the coast into early next week, with high resolution model guidance indicating better chances of widespread clearing in the afternoons (yes, even for the beaches) tomorrow and Monday. The marine layer is expected to deepen for the middle to end of next week as a more amplified trough of low pressure approaches the West Coast.

Building high pressure from the south will bring an increase in high temperatures, which will peak on Sunday. On Sunday, high temperatures will be around 5 degrees above average near the coast and 10 degrees above average for inland locations. The High Desert is likely (80-100% chance) to see high temperatures of 100 degrees or more by Sunday, while the lower deserts have similar chances of 110 degrees or more. HeatRisk in the inland valleys, mountain foothills, and deserts will be moderate, with locally high HeatRisk in the low deserts on Sunday. NBM chance for the low desert to exceed 115 degrees on Sunday is 15 percent or less. West of the mountains, there is a 50 to 80 percent chance parts of the Inland Empire will exceed 100 degrees and up to a 20 percent chance parts of eastern San Diego County valleys will exceed 100 degrees Sunday.
Portions of inland Orange County (east of Interstate 5) have a 30 to 50 percent chance of temperatures exceeding 90 degrees.

A low pressure system moving inland through California early in the week will strengthen onshore flow for Monday and Tuesday. This will result in a slight increase in westerly winds over the mountains and into the deserts. The weak low will also have minor impacts on lowering high temperatures. Temperatures Monday are expected to be a degree or two cooler than Sunday. Further cooling is expected into Tuesday, with high temperatures around 5 degrees above average.
Wednesday may see a few degrees of warming away from the coast as the ridge rebounds in the wake of the passing trough. Any increase in temperatures will be short lived as another upper level trough begins to deepen and move west across the Pacific Northwest for the end of the week. While there are some differences in the timing of the progression of this trough, the general consensus is for cooling the remainder of the week, with these differences determining just how much cooling will occur.

AVIATION
150330Z
Coast/Valleys
Low clouds have already developed along the San Diego coast, with bases 800-1200ft MSL. Inland spread up to 15 miles is expected through 14z, with bases varying between 600- 1100ft MSL. VIS may fall to 1/2-3SM for coastal terrain and inland valleys, especially around 10-14z. Otherwise, VIS generally above 5SM. Low clouds retreat towards the coast around 14-16z, with full clearing expected by 17-18z. High clouds generally above 25000ft will prevail through the afternoon. Low clouds develop again Sunday night generally after 06z, with slightly lower bases than tonight.

Mountains/Deserts
SCT-BKN high clouds and mostly unrestricted VIS prevails through Sunday.

MARINE
No hazardous marine conditions are expected through Thursday.

BEACHES
A 3 foot southerly (190 degrees) swell at 19 seconds has lead to elevated surf of 3 to 6 feet, primarily for Orange County and northern San Diego County beaches. A Beach Hazard Statement is in effect through late Sunday evening. The period gradually shortens to 17 seconds by Sunday, and the overall swell and surf heights will wane late Sunday into Monday.

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

SGX WATCHES/WARNINGS/ADVISORIES
CA...Beach Hazards Statement through Sunday evening for Orange County Coastal Areas.

PZ...None.