Today was likely the hottest day through the middle of next week. There will be a gradual cooling through the weekend into the middle of next week. Areas of dense fog are expected tonight into Friday morning on the coastal mesas. The marine layer is expected to deepen over the weekend, decreasing the likelihood of dense fog near the coast.
For extreme southwestern California including Orange, San Diego, western Riverside and southwestern San Bernardino counties,
Several maximum temperature records were tied or broken today at inland locations. A few locations in the lower deserts reached 120 degrees. This evening, some mid and high clouds have moved in from the south and could minor impacts on overnight temperatures and the formation of the marine layer low clouds and fog. However, it's still likely that some low clouds will develop along with locally dense fog on elevated coastal terrain.
From previous discussion, Highs on Friday are expected to be 3 to 5 degrees cooler than today for most locations, with continued cooling into next week as the dominant high pressure ridge centered over NM weakens slightly and becomes reoriented as it shifts to the southwest. The upper high becomes centered over SoCal by next Tuesday. By Saturday, highs will be near to slightly below normal for the coast and 3 to 6 degrees above normal for the eastern valleys and deserts. The slow cooling trend will continue for the next week with high temperatures falling 5 to 10 degrees through Thursday of next week with high temperatures for next Thursday a few to around 5 degrees below average for the coast and valleys with the deserts a few degrees above average.
The marine layer will deepen late in the weekend into next week with night and morning coastal low clouds and fog extending into portions of the western valleys. There could be some increase in monsoonal moisture during the middle of next week. Nbm chances for thunder for the mountains and deserts Wednesday and Thursday have decreased to around 5 percent, down from 10 percent yesterday.
080315z. Coast, Areas of low clouds will gradually develop and increase after 09Z, with best chances of cigs 10-15Z, but will likely not achieve uniform coverage with highest confidence in cigs forming over SD County sites. Bases will be 300-600 feet MSL with vis reduced 3-5SM at sea level and 0-2SM on mesas and higher coastal terrain. Scatter out Friday 15-16Z with high clouds AOA 15K ft MSL through the afternoon.
.Valleys/Mountains/Deserts, Hazy but VFR conditions prevail through Friday.
Smoke from area fires, mostly the Gifford Fire in Santa Barbara County, will continue to be present at or above 10,000 feet MSL. Surface conditions hazy but still VFR.
No hazardous marine conditions are expected through Tuesday.
Ca, Heat Advisory until 8 PM PDT Friday 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-Santa Ana Mountains and Foothills.
Extreme Heat Warning until 8 PM PDT Friday for Coachella Valley- San Diego County Deserts-San Gorgonio Pass near Banning.
PZ, None.
