Above average high and low temperatures from coast to the deserts through Thursday. Showers and thunderstorms possible this afternoon over the mountains and locally into the High Desert. Very limited thunderstorm chances for Wednesday. High temperatures will cool to within a few degrees of average, with lows expected to remain a few degrees above average through the weekend. Monsoonal moisture will increase for Thursday through the weekend with chances of afternoon showers and thunderstorms mainly over the mountains and deserts.
For extreme southwestern California including Orange, San Diego, western Riverside and southwestern San Bernardino counties,
, UPDATED AVIATION DISCUSSION,
High pressure aloft will keep both high and low temperatures above average through Thursday. Today will see additional chances of showers and thunderstorms mainly confined to the mountains with the potential for showers/thunderstorms to drift into the High Desert. Overall rainfall rates will be less than 0.50", with only a 10 percent chance of rainfall rates exceeding 0.50". Thunderstorm chances decrease into Wednesday as the heat peaks.
High temperatures on Wednesday will be mostly 5 to 10 degrees above average. Low temperatures on Wednesday will be around 5 to 8 degrees above average, up to 10 to 15 degrees above average on mountain foothills and slopes. The warm nights will contribute more to the higher HeatRisk for the next few days. The daytime heat will be mostly not record setting. However, there could be a few records tied or broken in the mountains for record warm low temperatures. After a decrease in mid-level moisture Wednesday, precipitable water values will begin increasing again on Thursday with the higher values for Friday through next weekend.
For early next week, the upper level ridge of high pressure will start to drift south and west more over the Four Corners region. This will leave the door for monsoonal moisture open, keeping daily chances for afternoon showers and thunderstorms over the mountains, locally into the deserts. High temperatures will remain near normal, with low temperatures expected to remain above average.
150500z. Coast/Valleys, SKC and VFR conditions expected through early Wednesday morning. Areas of low clouds based 600-1000 ft MSL are expected to develop over coastal San Diego County 10-12z Wed. Patchy clouds may briefly develop over coastal Orange County after 12z. Minor vis reductions (1-5SM) expected for elevated coastal terrain and western valleys (I-15 corridor). Low clouds scatter back to the coast by 15-16z. Otherwise, VFR conditions prevail with FEW high clouds above 10 kft Wednesday afternoon.
Mountains/Deserts, SCT Cu based around 10,000 ft along with ISOLD SHRA over mountain ridges Wednesday afternoon. Otherwise, FEW-SCT high clouds AOA 15,000 ft.
No hazardous marine conditions are expected through Saturday.
Astronomical high tides peaking 7.0-7.5 ft currently will peak again around 6.5-7.0 feet Wednesday evening. High tides combine with a modest south swell (2 ft swell at 13-15 seconds from 190 degrees) to generate surf of 3-5 ft for south-facing beaches and 2-4 ft elsewhere. This will produce areas of coastal flooding in low lying areas, boardwalks, beach parking lots, and beach adjacent streets during evening high tides. A Beach Hazards Statement remains in effect through Wednesday evening and contains further details. There will be an increased risk of rip currents through Wednesday.
Ca, Beach Hazards Statement through Wednesday evening for Orange County Coastal Areas-San Diego County Coastal Areas.
Heat Advisory from 10 AM Wednesday to 8 PM PDT Thursday for Orange County Coastal Areas-San Diego County Coastal Areas.
Extreme Heat Warning from 10 AM Wednesday to 8 PM PDT Thursday for Orange County Inland Areas-Riverside County Mountains- San Bernardino County Mountains-San Bernardino and Riverside County Valleys-The Inland Empire-San Diego County Mountains-San Diego County Valleys-San Gorgonio Pass near Banning-Santa Ana Mountains and Foothills.
Extreme Heat Warning until 8 PM PDT Thursday for Coachella Valley-San Diego County Deserts.
PZ, None.
