Gusty northerly winds through Friday along south-facing mountain slopes and through the Cajon Pass into the Inland Empire. Offshore winds turn more northeasterly this weekend and expand to include all coastal mountain slopes and valleys as a low pressure system drifts south of the area. This system will bring a slight chance of showers, mostly in San Diego County, on Monday. Warmer through Sunday followed by minor cooling Monday and Tuesday, then much warmer Wednesday through Friday.
For extreme southwestern California including Orange, San Diego, western Riverside and southwestern San Bernardino counties,
Evening Update, Skies are clear this evening under weak offshore flow. Water vapor imagery shows the next short wave trough digging south through interior California. As it moves south tonight, surface pressure gradients will tighten and upper level support will increase, driving a resurgence of north to northeast winds across the San Bernardino Mountains into the Inland Empire and Santa Ana Mountains. Wind gusts in the prone areas will range from around 35-45 mph with isolated gusts to 50 mph. Winds will briefly weaken again Friday afternoon. A Wind Advisory remains in effect for these areas through 4 PM Friday.
Previous discussion, By Friday evening, a robust shortwave trough will begin to drag the longwave trough back to the southwest. Current guidance shows this piece of energy working to strengthen the upper flow as it moves across southern California sometime early Saturday. This in combination with a developing surface high over the intermountain west may cause for quite strong northeasterly winds to surface along coastal slopes and into inland valleys on Saturday. Nbm probability of exceeding 60 mph gusts in areas surrounding the Cajon Pass is 60-90%. Thus, a High Wind Watch has been posted for Saturday along the San Bernardino County coastal slopes and into the northern Inland Empire. In addition, the northeasterly direction should allow gusty winds to expand to include all coastal slopes and inland valleys through the remainder of the weekend.
As the trough axis continues to dive southwest this weekend, it will begin to entrain moisture from the ocean. There is a slight chance for showers, mainly over San Diego County from Sunday night into Monday. However, guidance continues to trend drier as the low pushes further south and east with recent model runs. Regardless, no impacts from precip are expected at this time.
Beyond Monday, there is good agreement that an upper ridge will move in from the west. Warm and sunny conditions should prevail through the middle of next week with no signs yet of unsettled weather, thereafter.
060545z. Coast/Valleys, Mostly clear skies then FEW-SCT high clouds Friday evening. N/NE gusts to 25-35 kts in the Inland Empire below mountain passes and inland Orange County 08z Fri through 02z Sat, remaining elevated thereafter. Moderate confidence on winds reaching 35 kts at KONT and high confidence for 25 kts at KSNA Friday. Areas of LLWS and mod up/down drafts expected.
Mountains/Deserts, Mostly clear and VFR conditions through Friday evening. Gusty N/NE winds expected throughout the period: 25-40 kts with isold 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 Friday.
Strong northwest winds with gusts up to 25 kts are causing choppy and hazardous conditions through this evening. A Small Craft Advisory contains the details. No additional hazardous marine conditions are expected through Monday.
Ca, Wind Advisory until 4 PM PST Friday for Orange County Inland Areas-San Bernardino County Mountains-San Bernardino and Riverside County Valleys-The Inland Empire-Santa Ana Mountains and Foothills.
High Wind Watch from late Friday night through Saturday afternoon for San Bernardino County Mountains-San Bernardino and Riverside County Valleys-The Inland Empire.
PZ, Small Craft Advisory until 10 PM PST this evening for Coastal Waters from San Mateo Point to the Mexican Border and out to 10 nm-Waters from San Mateo Point to the Mexican Border Extending 10 to 60 nm out including San Clemente Island.
