Hot conditions with record breaking temperatures this week. Weak offshore flow is expected today, with east to northeast wind gusts 25 to 45 mph along and below the coastal slopes of the mountains. Some cooling is expected through the weekend into early next week. Even with the cooling high temperatures will remain above average. Marine layer low clouds and fog will be largely absent from the coast this week, potentially returning by late this weekend.
For extreme southwestern California including Orange, San Diego, western Riverside and southwestern San Bernardino counties,
Weak offshore flow is being observed across the area as of 11 AM. The strongest northeast to east winds are being observed on the coastal mountain slopes and below passes with peak gusts 30 to 45 mph. These offshore winds combined with building high pressure aloft will make for a toasty day, especially for the coast and western valleys. Temperatures in both coastal and inland Orange County are running 15 to 25 degrees warmer than this time yesterday. Further south in San Diego County, temperatures are running 7 to 15 degrees warmer than yesterday. A few daily high and low temperature records were broken yesterday with more expected to be broken today. Widespread moderate to locally major HeatRisk is expected each day this week. Reduce outdoor activities if possible between 10 AM and 5 PM, seek shade, and stay hydrated.
Places along the immediate coast will see some relief from the heat Wednesday onward, as weak onshore flow returns. That won't be the case for inland locations, with an addition 3 to 5 degrees of warming on Wednesday and even further warming for Thursday and Friday. The high pressure aloft will peak in strength on Thursday or Friday with high temperatures 20 to 30 degrees above average for this time of year. Daily and monthly temperature records are expected to be broken or tied for locations like Ramona, Big Bear Lake, Idyllwild, Palm Springs, and Borrego Springs. More information on monthly temperature records can be found in the climate section below. Overnight lows will also be elevated, which will limit overnight relief from the heat for most locations.
Weakening high pressure aloft and strengthening onshore flow will bring 5 to 7 degrees of cooling to place west of the mountains Saturday, with cooling spreading to the mountains and deserts Sunday and Monday. Weak ridging aloft will maintain highs 10 to 20 degrees above average across the area through at least next Tuesday. Much of this week will see an absence of marine layer low clouds and fog, with the potential for clouds and fog to return to coastal areas late in the weekend or early next week.
171800z, VFR conditions expected through the TAF period. Gusty winds around 25-30 kts out of the northeast are beginning to decrease and will continue to do so through 21Z. Isolated low clouds along the coast beginning near KSAN after 05Z and stretching north near KCRQ after 06Z. Not expecting any impacts to cigs or vis at coastal airports.
No hazardous marine conditions are expected throughSaturday.
A long period (17-19 second) south-southwesterly swell (190-200 degrees) to 3-5 feet will continue today, bringing occasional surf sets up to 6 feet on south-facing beaches, before decreasing Wednesday evening. Locally hazardous swimming conditions are expected. A Beach Hazards Statement contains more details.
Ca, Beach Hazards Statement through Wednesday evening for Orange County Coastal Areas-San Diego County Coastal Areas.
Heat Advisory until 8 PM PDT Friday for Orange County Coastal Areas-Orange County Inland Areas-San Bernardino and Riverside County Valleys-The Inland Empire-San Diego County Coastal Areas-San Diego County Valleys-Santa Ana Mountains and Foothills.
Heat Advisory from 10 AM Wednesday to 8 PM PDT Friday for Riverside County Mountains-San Bernardino County Mountains- San Diego County Mountains.
Extreme Heat Warning from 10 AM Wednesday to 8 PM PDT Saturday for Coachella Valley-San Diego County Deserts-San Gorgonio Pass near Banning.
PZ, None.
