High temperatures into early next week will generally range from a few degrees above average near the coast to 5 to 10 degrees above average for the mountains and deserts with some minor day-to-day differences. Minor to moderate HeatRisk, heat-related impacts affecting those sensitive to heat, will continue for the inland valleys and deserts through next Wednesday. Marine layer low clouds will spread into portions of the western valleys during the nights and early mornings, with day-to-day variations. A cooling trend with a deepening marine layer will follow mid to late next week.
For extreme southwestern California including Orange, San Diego, western Riverside and southwestern San Bernardino counties,
This afternoon, The marine layer remains about 1500 ft deep with a relatively strong inversion. Low clouds persist at the immediate coast this afternoon and will likely begin to spread inland in the late afternoon, extending up to 10 miles inland by sunrise on Sunday. The marine layer may be shallower Sunday morning than it was this morning as high-resolution models show minor height rises aloft and no indications of a coastal eddy. Temperatures are currently a few degrees lower than at this time yesterday except in the IE where it's a few degrees higher. The mid-level moisture from yesterday is mostly gone as the flow aloft has become more south westerly than southerly but enough remains for a few mid-level clouds and some cumulus over the mtns this afternoon.
SoCal will remain sandwiched between a high over the eastern North Pacific and one over TX/Mexico. This pattern will likely evolve into a Rex Block by Tue as a closed upper low moves into position south of the high off the NorCal coast. This will bring us mostly typical June weather through next Wed except for daytime temperatures which will be mostly a few to about 5 degrees above average for coastal regions and 5 to 10 degrees above average for far inland areas, including the mountains and deserts. Low temperatures will similarly be 5 to 10 degrees above average most place, with parts of the mountains and deserts seeing lows up to about 15 degrees above average. The marine layer will see minor day-to-day variations in depth, and the low clouds will return to the coastal areas and western portions of the inland valleys each night and morning.
For the latter half of next week, the east PAC high is weakened and displaced as a low pressure system moves into the Pacific Northwest. There is still significant uncertainty in the details but we will likely see a trend toward cooler conditions with a deepening marine layer allowing low clouds to spread farther inland during the nights and mornings. Current model solutions indicate that temperatures next Sat will be near or up to 11 degrees below normal.
140000z, Coast/Western Valleys, Low clouds are very patchy off the coast this afternoon. Confidence on exact timing coastal cloud development is low - patchy clouds possible for coastal areas 01- 05z, expanding inland up to 10-20 miles through 10z, still remaining patchy. Bases 800-1200 ft MSL, settling mostly below 1000 ft MSL early Sunday. VIS 0-5SM in valleys east of I-15 in SD County and elevated coastal terrain. Scatter to beaches 15-17z Sun, then VFR conditions prevail through Sunday afternoon.
Mountains/Deserts, VFR conditions are expected through Sunday afternoon with high clouds AOA 10 kft MSL. Gusty onshore winds through desert slopes and San Gorgonio Pass into the Coachella Valley bringing gusts 20-30 kts this afternoon/evening.
No hazardous marine conditions are expected through Wednesday.
Ca, Beach Hazards Statement through Monday evening for Orange County Coastal Areas-San Diego County Coastal Areas.
PZ, Beach Hazards Statement through Monday evening for Coastal Waters from San Mateo Point to the Mexican Border and out to 10 nm.
