textproduct: San Diego

SYNOPSIS

Near seasonal temperatures through the first half of the week followed by minor warming Wednesday through Sunday. Chances for afternoon showers remain confined to the higher mountain peaks through Wednesday, with the potential for more widespread shower and thunderstorm activity for the latter half of next week. The marine layer will remain mostly confined to the coast, reaching into portions of the valleys at times.

..UPDATED AVIATION DISCUSSION

Marine layer low clouds continue to fill in along the coast and up to 10 miles inland this morning, otherwise just a few mid level clouds are moving west from earlier convection over AZ. Low clouds will clear by late morning. The 00Z KNKX sounding shows Precipitable Water had decreased to around 1.5" with stable conditions. Ensembles show little change in moisture and instability today and Monday, with any showers limited to the higher peaks of the San Bernardino Mountains (15% chance) and thunderstorm chances are less than 10%. Moisture decreases slightly on Tuesday for even lower chances of showers and thunderstorms (10% or less).

An upper level high remains over the Central Rockies into Tuesday with little day to day changes in the weather over So Cal. High temperatures will be near seasonal averages - general mid to upper 70s at the beaches to mid 80s to mid 90s in the valleys, upper 70s to mid 80s in the mountains, mid 90s to around 100 in the high desert, and 100-110 in the low desert. Areas of night and morning low clouds will continue along the coast and into the far western valleys.

For the latter half of the week, the upper level high shifts south towards OK/TX Wed-Thu and then slowly shifts westward into next weekend. Ensembles continue to show an increase in PW during this period, as well as increasing MUCAPE over the mountains. However, ensembles are also showing the east-west ridge axis directly overhead, which would help suppress convection during the afternoons. NBM PoPs have trended downwards for Thursday (15-30% chance over the mountains) but remain higher for Friday (25-40% chance). Warming is more certain, especially west of the mountains, for the latter half of the week with high temperatures increasing to around 5 degrees above normal. Less certainty in the low deserts as any low-level moisture surges will keep daytime temperatures lower - not that it will feel any better with an increase in humidity. Otherwise a shallower marine layer with the potential for patchier cloud cover during the nights and mornings.

Mountains/Deserts

VFR conditions expected through the period with FEW-SCT mid-level clouds generally AOA 15,000ft MSL. FEW-SCT Cu based 10-12 kft MSL may develop over the mountain ridgetops Sunday afternoon, with a small (10%) chance for ISO SHRA/TSRA, most likely after 21z through 01z Mon.

Otherwise, west winds gusting 20-35 kts along desert slopes 02-09z Mon (up to 45 kts through the Banning Pass).

MARINE

Wednesday afternoon, there is around a 50% chance for northwesterly wind gusts to exceed 20 kts in the outer waters near San Clemente Island. Otherwise, no hazardous marine conditions are expected through Thursday morning.

BEACHES

High amplitude southerly swell (4-5 ft with a period of 11-13 seconds) will build today, bringing elevated to high surf and strong rip and longshore currents through at least Tuesday. Highest surf, up to 7-8 ft, will be along south and southwest-facing beaches. Further details can be found in the High Surf Advisory. Surf falls a bit Tuesday and into Wednesday before another southerly swell (4-5 ft with a period of ~15 seconds) brings another round of elevated to high surf for the end of the week and into the early weekend. The high risk for strong rip currents will remain through the end of the week.

SKYWARN

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

SGX WATCHES/WARNINGS/ADVISORIES

CA...High Surf Advisory from 5 PM this afternoon to 11 PM PDT Tuesday for Orange County Coastal Areas-San Diego County Coastal Areas.

PZ...None.