Ation DISCUSSION BELOW,
.PREVIOUS DISCUSSION, Issued 200 AM PDT Sun Jun 21 2026, This morning, The marine layer remains about 3,000 ft deep with low-zonal flow over SoCal and weak troughing just to our north. Low clouds are increasing in coverage over the coastal areas and valleys of San Diego County. The cloud coverage seems to be expanding in a similar pattern to yesterday (Friday) morning. The saturated layer is relatively thin and the inversion weak so clearing will likely be as early this morning as yesterday morning.
A warming trend will continue into Thursday as high pressure builds over the western states. Wed and Thu will likely be the warmest days with the center of the upper high over northern Mexico. Daytime high temperatures on those days will likely be 5 to 10 degrees above average for inland locations with localized areas of moderate HeatRisk away from the coast, and areas of major HeatRisk in the low desert. Most model solutions continue to show an influx of mid-level moisture from the south around the middle of the week. If this brings significant cloud cover, it could suppress temperatures during the daytime and inhibit radiation cooling at night - at least on Wed and Thu. The possibility of showers and/or tstms can't be ruled out for Wed afternoon but at this time, the probability is 15 percent or less. The marine layer will be shallower and overnight low clouds may be patchy and disrupted by the moisture aloft.
Beyond the middle of the week, Model solutions are coming into better agreement with respect to a low pressure system moving inland to our north, with a closed upper low over WA state by next Saturday morning. A majority of ensemble members now show the ridge of high pressure beginning to weaken and shift east by Thursday as a low pressure trough approaches the west coast. This will result in a cooling trend beginning on Friday with next Sunday being the coolest day overall. High temperatures will be within a degree or 2 of normal in the coastal areas and low deserts while in the valleys, mtns and high desert daytime high temps will be anywhere from 3 to 11 degrees below normal. The marine layer will again deepen with low clouds spreading inland to the coastal mtn slopes during the nights and mornings.
Below average temperatures with marine layer low clouds and fog reaching into portions of the valleys this weekend. For the first half of the week, 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. The marine layer will become shallower next week, staying confined to coastal locations. Gradual cooling expected for the second half of the week.
For extreme southwestern California including Orange, San Diego, western Riverside and southwestern San Bernardino counties,
, UPDATED AVIATION DISCUSSION BELOW,
.PREVIOUS DISCUSSION, Issued 200 AM PDT Sun Jun 21 2026, This morning, The marine layer remains about 3,000 ft deep with low-zonal flow over SoCal and weak troughing just to our north. Low clouds are increasing in coverage over the coastal areas and valleys of San Diego County. The cloud coverage seems to be expanding in a similar pattern to yesterday (Friday) morning. The saturated layer is relatively thin and the inversion weak so clearing will likely be as early this morning as yesterday morning.
A warming trend will continue into Thursday as high pressure builds over the western states. Wed and Thu will likely be the warmest days with the center of the upper high over northern Mexico. Daytime high temperatures on those days will likely be 5 to 10 degrees above average for inland locations with localized areas of moderate HeatRisk away from the coast, and areas of major HeatRisk in the low desert. Most model solutions continue to show an influx of mid-level moisture from the south around the middle of the week. If this brings significant cloud cover, it could suppress temperatures during the daytime and inhibit radiation cooling at night - at least on Wed and Thu. The possibility of showers and/or tstms can't be ruled out for Wed afternoon but at this time, the probability is 15 percent or less. The marine layer will be shallower and overnight low clouds may be patchy and disrupted by the moisture aloft.
Beyond the middle of the week, Model solutions are coming into better agreement with respect to a low pressure system moving inland to our north, with a closed upper low over WA state by next Saturday morning. A majority of ensemble members now show the ridge of high pressure beginning to weaken and shift east by Thursday as a low pressure trough approaches the west coast. This will result in a cooling trend beginning on Friday with next Sunday being the coolest day overall. High temperatures will be within a degree or 2 of normal in the coastal areas and low deserts while in the valleys, mtns and high desert daytime high temps will be anywhere from 3 to 11 degrees below normal. The marine layer will again deepen with low clouds spreading inland to the coastal mtn slopes during the nights and mornings.
211800z, Coast/Valleys, Lingering low level clouds along the coast will clear offshore by 19Z. Low clouds reform and move into SD coastal regions after 03Z at 1700-2200 ft MSL, then into inland SD/Orange County after 06Z. There is a 30-40% chance for clouds to reach into the southern and northwest portions of the Inland Empire, including vcnty KONT, 11-16Z Monday. Cigs likely to lower slightly overnight to 1500-2000 ft MSL, then scatter out 16-18Z Mon.
Mountains/Deserts, VFR conditions with periods of upper level clouds AOA 20k ft expected through the TAF period. Westerly wind gusts of 25-40 kts along desert slopes and locally into deserts expected through about 06Z this evening. Local VIS reductions 4-6 SM in BLDU during periods of strong gusts and moderate up/downdrafts in lee of mtns.
No hazardous marine conditions are expected through Thursday.
Elevated surf and strong rip currents are set to continue through this weekend with a persistent long period southwesterly swell. Surf of 3-5 feet with local sets to 6 feet are expected at southwest- facing beaches. Expect locally hazardous swimming conditions with high rip current and longshore current risk. See the Beach Hazards Statement for more details.
Ca, Beach Hazards Statement through this evening for Orange County Coastal Areas-San Diego County Coastal Areas.
PZ, None.
