Aviation AND MARINE DISCUSSIONS BELOW,
At noon, visible satellite was showing widespread high cloud coverage from the coast to the deserts, with areas of low clouds under the high clouds west of the mountains. Temperatures at noon were running 4 to 10 degrees cooler than they were at noon yesterday. Westerly winds are expected over the mountains and into the deserts through this evening with peak gusts 45 to 55 mph. Winds will weaken tonight and turn offshore by Friday morning.
As the upper level low that is bringing our cool, cloudy, and windy weather quickly moves east into the Intermountain West Friday, surface pressure gradients will rapidly turn offshore. This will result in an uptick of north to northeasterly winds Friday morning. Strongest winds will be on the coastal foothills of the San Bernardino and Santa Ana mountains, through the Cajon Pass, through the San Gorgonio Pass, and into portions of the Inland Empire and Orange County east of Interstate 5. Peak gusts of 35 to 55 mph are expected. In addition to increased winds west of the mountains, conditions will warm with highs Friday for the coast and valleys forecast to be 10 to 15 degrees warmer than today.
The aforementioned low will be very quick moving, which will result in rapidly weakening surface pressure gradients for Saturday and Sunday. While the gradient will remain offshore, winds are expected to become weaker and more localized. Weak ridging aloft is expected to build over California over the weekend, continuing a period of above average temperatures.
For next week, the pattern becomes fairly dynamic. A shortwave trough will move through Southern California Monday which will bring a few degrees of cooling. By Tuesday, weak ridging will be over the area which will boost temperatures a few degrees. By Wednesday and next Thursday a larger area of low pressure aloft will slowly make it's way towards the US West Coast. There remains some uncertainty in the ensemble guidance in regards to the timing of the low and how far south it will dig. We will likely see cooler, cloudier, and windier conditions again. There are some ensemble members on the GEFS and ECMWF that indicate chances of precipitation. There remains uncertainty in how the upper level pattern will shape up which will impact the temperature, wind, and precipitation forecast.
Gusty west winds will continue over the mountains and into the deserts through this evening. Winds will quickly turn offshore Friday morning, with gusty Santa Ana winds expected through Friday evening. Weaker northeast winds with dry and warm conditions expected for the weekend. Temperatures will fluctuate a few degrees each day next week, but mostly stay above average for this time of year. Periods of night and morning low clouds next week.
For extreme southwestern California including Orange, San Diego, western Riverside and southwestern San Bernardino counties,
, UPDATED 00Z AVIATION AND MARINE DISCUSSIONS BELOW,
At noon, visible satellite was showing widespread high cloud coverage from the coast to the deserts, with areas of low clouds under the high clouds west of the mountains. Temperatures at noon were running 4 to 10 degrees cooler than they were at noon yesterday. Westerly winds are expected over the mountains and into the deserts through this evening with peak gusts 45 to 55 mph. Winds will weaken tonight and turn offshore by Friday morning.
As the upper level low that is bringing our cool, cloudy, and windy weather quickly moves east into the Intermountain West Friday, surface pressure gradients will rapidly turn offshore. This will result in an uptick of north to northeasterly winds Friday morning. Strongest winds will be on the coastal foothills of the San Bernardino and Santa Ana mountains, through the Cajon Pass, through the San Gorgonio Pass, and into portions of the Inland Empire and Orange County east of Interstate 5. Peak gusts of 35 to 55 mph are expected. In addition to increased winds west of the mountains, conditions will warm with highs Friday for the coast and valleys forecast to be 10 to 15 degrees warmer than today.
The aforementioned low will be very quick moving, which will result in rapidly weakening surface pressure gradients for Saturday and Sunday. While the gradient will remain offshore, winds are expected to become weaker and more localized. Weak ridging aloft is expected to build over California over the weekend, continuing a period of above average temperatures.
For next week, the pattern becomes fairly dynamic. A shortwave trough will move through Southern California Monday which will bring a few degrees of cooling. By Tuesday, weak ridging will be over the area which will boost temperatures a few degrees. By Wednesday and next Thursday a larger area of low pressure aloft will slowly make it's way towards the US West Coast. There remains some uncertainty in the ensemble guidance in regards to the timing of the low and how far south it will dig. We will likely see cooler, cloudier, and windier conditions again. There are some ensemble members on the GEFS and ECMWF that indicate chances of precipitation. There remains uncertainty in how the upper level pattern will shape up which will impact the temperature, wind, and precipitation forecast.
030000z, Coast/Valleys/Foothills, SCT-BKN low clouds based 2500- 4500 ft MSL through the coastal basin currently. Clouds will lower some and increase in coverage through this evening for San Diego County and the southern Inland Empire. Elsewhere clouds will slowly clear out through tonight as winds turn offshore. Low clouds eventually clear out of all areas around 09-12Z Fri. Simultaneously, north to northeast winds pick up along coastal slopes, foothills, and downwind of the Cajon/Banning Passes into the Inland Empire. Gusts 35-50 kts expected for coastal slopes of the San Bernardino/Santa Ana mtns and just below the Cajon Pass. Gusts 25-35 kts elsewhere.
Mountain ridges/deserts, VFR conditions expected through Friday evening. Strong westerly winds with gusts 30-45 kts through passes, on desert slopes and locally into the High Desert through 06Z Friday. Gusts reaching 25-35 kts along the floor of the lower desert. Areas of BLDU expected with vis 3-5SM. Winds turn northeast early Friday morning and weaken for most areas. The exception will be the Coachella Valley with gusts 25-35 kts at KPSP and KTRM through early Friday afternoon.
Northwest wind gusts will occasionally exceed 20 knots near San Clemente Island this afternoon and evening. Otherwise, no hazardous marine conditions expected through Tuesday.
Ca, Wind Advisory from 5 AM to 8 PM PDT Friday for Orange County Inland Areas-San Bernardino County Mountains-San Bernardino and Riverside County Valleys-The Inland Empire-San Gorgonio Pass near Banning-Santa Ana Mountains and Foothills.
Wind Advisory until 11 PM PDT this evening for Apple and Lucerne Valleys-Coachella Valley-Riverside County Mountains-San Bernardino County Mountains-San Diego County Deserts-San Diego County Mountains-San Gorgonio Pass near Banning.
PZ, None.
