Warming conditions expected this week. Hottest conditions are expected Thursday through Saturday for most locations, potentially into Sunday for the deserts. Moderate HeatRisk is expected across inland areas. The marine layer is expected to get shallower, staying confined to coastal areas through much of this week.
For extreme southwestern California including Orange, San Diego, western Riverside and southwestern San Bernardino counties,
High temperatures today are expected to be a few degrees warmer than yesterday for most locations. An additional 3 to 5 degrees of warming is expected on Tuesday, which will bring conditions to a few degrees above average for inland areas and up to 8 degrees above average for the coast.
High pressure aloft will build over the Pacific for the middle to end of the week. Through the forecast period the ridge axis is expected to stay to our west, but with California in it's periphery highs will increase. Warmest conditions will likely be Thursday through Saturday, with highs 6 to 12 degrees above average. Areas of moderate HeatRisk are expected for the Inland Empire and the deserts, with more localized areas of moderate HeatRisk in the far eastern San Diego county valleys. Widespread moderate with areas of localized major HeatRisk expected in the low deserts on Saturday. Based on current forecast, high temperatures do not look record breaking but some low temperature records will be in jeopardy.
The position of the ridge could allow for some subtropical moisture to sneak into the southwestern United States by the end of the week. Ensemble members of both the GEFS and ECMWF show a notable increase in precipitable water into the low deserts Friday, with less but still elevated precipitable water Saturday and Sunday. The forecast looks to remain dry at this time so it looks like the main impact from this moisture surge would be tempering the highs across the deserts and an increase in high clouds. Current forecast for the low deserts is 108-112 degrees Friday and Saturday, but if the moisture surge materializes high temperatures would likely be lower than that.
There is some uncertainty with highs Sunday, especially for the desert areas. Highs in the desert have the potential to be hotter on Sunday compared to Friday/Saturday if the moisture surge is significantly weaker. There is higher confidence that areas west of the mountains will cool a degree or two by Sunday.
For much of this week the marine layer is expected to be on the shallower side, staying confined to coastal areas.
081800z, Coast/Valleys, Low marine layer clouds have cleared out quickly this morning, with only FEW clouds lingering along the coastal areas into the afternoon. Low clouds to redevelop and push back ashore after 00z Tuesday, initially across San Diego County, eventually spreading northward into Orange County and into portions of the western/southern Inland Empire by 12z (only a 10-20% chance of CIGs reaching KONT between 12-16z). Cloud bases will likely be lower than this morning (1400-1800ft MSL) but could be a bit patchy at times. Similar scattering out time as this morning, around 16-17z Tuesday.
Mountains/Deserts, VFR with SKC. Westerly winds return starting 21z Mon with gusts 20-35 kts along desert slopes and locally into deserts. Gusts exceeding 40 kts through the Banning Pass. Pockets of MOD up/downdrafts and LLWS in lee of mtns.
No hazardous marine conditions are expected through Thursday afternoon.
Surf and rip current activity to remain elevated (3-6 feet) through this evening. Surf increases Monday night into Tuesday morning as a fresh 3-4 foot swell at 18-19 seconds moves into the region. Surf peaks Tues-Wed with sets to 5-8 feet likely at south-facing beaches, then gradually diminishes late this week. See the Beach Hazards Statement for more details.
Ca, Beach Hazards Statement from late tonight through Thursday afternoon for Orange County Coastal Areas-San Diego County Coastal Areas.
PZ, None.
