Gusty Santa Ana winds will continue through the weekend across the mountains into the western valleys as an area of low pressure nears the region. This will also bring warmer weather with minimal cloud cover. The system will move southward into Mexico, where there is a small chance for light rain over San Diego County by late Sunday into Monday. High pressure will move over the region for much of next week, bringing warm and dry weather.
For extreme southwestern California including Orange, San Diego, western Riverside and southwestern San Bernardino counties,
GOES imagery shows shows an apparent trough of low pressure over Colorado and Utah today. Behind the trough, northerly flow aloft is bringing in high clouds over the region, which will continue into the early evening. Winds out of the north and northeast this morning have been gusting near 25-45 MPH across the valleys with winds locally over 50 MPH along the coastal slopes. These winds will become weaker and less widespread later this afternoon and overnight. The low over eastern Great Basin today will become cut off by Saturday and move closer to our region. This will allow the pressure gradient to become stronger once again, leading to increased winds across the coastal slopes and areas west of the mountains. Model guidance shows around a 50-70% chance of wind speeds over 40 MPH by Saturday morning across western portions of the Inland Empire down into Orange County, along with SD County coastal slopes. Winds will be higher along the coastal slopes of SBD/OC counties with moderate to high chances for winds over 55 MPH.
The area of low pressure will move further south on Saturday into Sunday, which will favor a more easterly wind component around the northern side of the system. These easterly winds will begin to lead to stronger winds across San Diego County during this time period. Highest winds will occur during the morning and afternoon hours each day. Moderate to high chances exist for foothill regions to reach 40 MPH, while valleys see these chances closer to 25-30 MPH. Offshore flow will also bring the greatest warming by Sunday. Western valleys will see moderate to high chances (50-80%) in seeing highs reach 85 degrees. There is about a 50-60% chance to reach 90 degrees across inland Orange County. These high temperatures would be 15-20 degrees above normal for early March. The low will wrap around minimal amounts of moisture with a slight increase in precipitable water values, which may be able to provide light rain showers from the deserts to the western valley regions in San Diego County by Sunday night into Monday. Chances remain low near 15-25 percent with high confidence in light amounts possible.
Ensemble models show good agreement on the movement of this system, pushing it out of the area by Tuesday. High pressure off the coast will move into the area for much of next week. Cooler weather returns on Monday as offshore winds weaken, but a warming trend continues through the week as high pressure off the Pacific strengthens over our region.
061800z. Coast/Valleys, VFR with FEW-SCT high clouds AOA 20,000ft MSL this afternoon and evening. N/NE gusts to 30-40 kts in the Inland Empire below mountain passes and 25-35 kts for inland Orange County periodically through Saturday evening. Weaker offshore winds (10-20kts) reaching the coasts this morning becomes onshore this afternoon before offshore resumes by 12z Saturday. Localized areas of LLWS and mod up/down drafts expected, especially in the lee of mountains.
Mountains/Deserts, VFR with FEW-SCT high clouds AOA 20,000ft MSL this afternoon and evening. Gusty N/NE winds expected into Saturday: 25-40 kts with isolated gusts to 55 kts through mountain passes and on coastal facing foothills. Areas of LLWS and mod up/down drafts in lee (south of) mountains mainly in SBD County. Low confidence on KPSP gusting to 35 kts today. BLDU may briefly lower VIS in the deserts, especially this afternoon. Brief lull in strong gusts expected from 02-10z Saturday, but gusts 30-40 kts expected in the mountains/passes during this period.
Intermittent gusts near 20 knots possible in the outer coastal waters near San Clemente Island early Saturday morning and again Sunday evening. Otherwise, no additional hazardous marine conditions are expected through Tuesday.
Ca, Wind Advisory until 5 PM PST Sunday for Orange County Inland Areas-San Bernardino County Mountains-San Bernardino and Riverside County Valleys-The Inland Empire-Santa Ana Mountains and Foothills.
Wind Advisory from midnight tonight to 5 PM PST Sunday for Riverside County Mountains-San Diego County Mountains-San Diego County Valleys-San Gorgonio Pass near Banning.
PZ, None.
