A warming trend is expected on Thursday into the weekend as high pressure strengthens over the area. This will lead to increased heat risk across the region, with warmer overnight temperatures. The hottest weather will occur on Saturday, with slight cooling into next week. The marine layer will maintain a shallower depth, bringing night and morning clouds near the coastal regions each day.
For extreme southwestern California including Orange, San Diego, western Riverside and southwestern San Bernardino counties,
Satellite shows low clouds melting away from SoCal offshore at this hour. Mostly clear conditions will continue through the afternoon, before low clouds move back inland this evening. High pressure anchored over New Mexico will strengthen and expand into the weekend. This will keep the marine layer thinner, confining low clouds within 10 miles from the coast each night and morning for much of the upcoming week.
The high's growth and transition westward will also bring a warmer weather to the area through the weekend. The warming trend begins on Thursday with temperatures rising another 1-3 degrees across the area. By Friday, the high strengthens right around 600 dm, indicating a greater increase in temperatures (this time, another 3-5 degrees warmer). The weather system peaks in intensity on Saturday with high temperatures around 5 to 10 degrees above normal. Widespread highs of 100 to locally near 110 can be expected across the Inland Empire and High Desert, potentially nearing 120 in the lower deserts. Widespread 80s and 90s will be felt across the mountains, western valleys and beaches. Overnight low temperatures will also be warm as more humid conditions remain. Please practice good heat safety by limiting outdoor recreation (mountains included!), taking water breaks, and seeking shade when you are able to do so.
The high's strength begins to weaken slightly by Sunday into early next week. Sunday's temperatures will be similar to Saturday across mountains and deserts, cooling slightly for areas west of the mountains as an increased sea breeze tries to cool things off a bit. High pressure remains over the desert southwest, albeit weaker, for the first half of next week. This will cool coastal areas and western valleys off closer to normal. Inland temperatures across mountains and deserts will remain elevated nearing ten degrees above normal; chances remain high for temperatures to stay above 110 degrees across the lower deserts at this time. Increases in low level moisture is also seen for inland regions by the middle of next week, so chances for rain and storms remain small, but increase slightly.
291730z. Coast/Valleys, Low clouds will redevelop along coast around 01-04Z, and move gradually inland into parts of the inland valleys overnight 06-13Z. Bases 1000-1500 feet MSL with tops around 1800 feet. Areas of vis inland reduced 0-5SM. Scatter out Thursday 15-17Z.
Mountains/Deserts, Mostly SKC with unrestricted VIS through early Thursday.
No hazardous marine weather is expected through Sunday.
Ca, Beach Hazards Statement until 5 PM PDT this afternoon for Orange County Coastal Areas-San Diego County Coastal Areas.
Coastal Flood Advisory from 5 PM this afternoon to 3 AM PDT Saturday for Orange County Coastal Areas-San Diego County Coastal Areas.
High Surf Advisory from 5 PM this afternoon to 5 PM PDT Saturday for Orange County Coastal Areas-San Diego County Coastal Areas.
Heat Advisory from 10 AM Friday to 8 PM PDT Sunday for Orange County Coastal Areas-San Diego County Coastal Areas.
Extreme Heat Warning from 10 AM Thursday to 8 PM PDT Sunday for Apple and Lucerne Valleys-Coachella Valley-Riverside County Mountains-San Bernardino and Riverside County Valleys-The Inland Empire-San Diego County Deserts-San Diego County Mountains-San Gorgonio Pass near Banning.
Extreme Heat Warning from 10 AM Friday to 8 PM PDT Sunday for Orange County Inland Areas-San Diego County Valleys-Santa Ana Mountains and Foothills.
Heat Advisory from 10 AM Thursday to 8 PM PDT Sunday for San Bernardino County Mountains.
PZ, None.
