textproduct: San Diego

SYNOPSIS

Warming trend for the first half of the week brings widespread moderate to areas of major HeatRisk possible for the deserts and widespread minor to locally moderate HeatRisk for inland Orange County, valleys, and mountains for Wednesday. The marine layer will become shallower through midweek, staying confined to coastal locations. A few stray showers/storms are possible over the mountains on Wednesday. Gradual cooling expected for the second half of the week with the marine layer becoming deeper.

..Updated Aviation, Marine, and Beach Discussion Below

Current satellite and 500mb analysis reveals largely zonal flow aloft and a weak upper ridge across northern Mexico, with marine layer clouds clearing out to the coasts for the day. Temperatures early this afternoon are running near to slightly warmer than yesterday, but is still coming in 5-10 degrees below normal for most across the region. However, today looks to be the coolest day of the next several as model guidance remains consistent in the upper level ridge strengthening and sliding northward over the next few days, becoming centered near El Paso by Tuesday afternoon. The placement of this ridge also establishes southeasterly flow aloft, allowing for an influx of mid level moisture into the area. The ridge and the moisture will likely serve to limit the vertical depth and inland extent of the marine layer through midweek. The main consequence will be the notable warming trend, that takes afternoon temperatures 5-10 degrees above normal by Wednesday. More importantly, the moisture will inhibit overnight cooling, leading to mild nights, with low temperatures running 5-10 degrees above normal as well and limiting overnight relief from he warm daytime temperatures. This brings areas of moderate HeatRisk into the inland valleys on Wednesday, with locally major HeatRisk for the deserts. Additionally, the increased mid level moisture could support the development of a few showers/storms over the mountains Tuesday or moreso Wednesday afternoon. A weak shortwave rounding the western periphery of the ridge Tuesday into Wednesday may provide enough synoptic support for updrafts to overcome inhibiting cloud cover and dry air above the moist layer, but these are 2 main factors that will likely keep any impacts from these precipitation chances little to none.

Ensembles continue to push a longwave trough into the Pacific Northwest for Thursday into Friday, which should help weaken the ridge and nudge it south/east as well as kick out the mid level moisture. This results in a cooling trend into the weekend with the marine layer deepening again. Temperatures return to near average for Thurs/Fri with the potential for afternoon highs 10 degrees or more below normal for the weekend.

AVIATION

220530Z...Coast/Valleys...Low clouds have formed along the San Diego coast with bases 1400-2000ft MSL. These clouds will continue to increase in coverage and push inland over the next few hours. Low clouds will spread north into Orange County after 08-09Z. The Inland Empire may see some low clouds overnight but would be patchy in nature. Low clouds will begin their retreat after 15Z, clearing the coast by 17-18Z. Cigs return 01-03Z Tuesday with slightly lower bases expected.

Mountains/Deserts...VFR conditions expected through the TAF period. Westerly wind gusts of 25-40 kts along desert slopes and locally into deserts expected through 09Z. Local VIS reductions 4-6 SM in BLDU during periods of strong gusts and moderate up/downdrafts in lee of mtns.

MARINE

No hazardous marine conditions are expected through Friday.

BEACHES

Surf heights have lowered slightly, but may become elevated again by Wednesday as fresh long-period southerly swell moves in. Strong rip currents will remain possible through the upcoming week.

SKYWARN

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

SGX WATCHES/WARNINGS/ADVISORIES

CA...Beach Hazards Statement until 11 PM PDT this evening for Orange County Coastal Areas-San Diego County Coastal Areas.

PZ...None.