Ation and Marine sections,
In Orange County, Northeast wind gusts between 25-45 mph are being observed from the Santa Ana Mountain foothills down to the coast locally. Gusts of 55-65 mph are seen in the southwest facing canyons, locally up to 76 mph in Fremont Canyon. Areas south of the Cajon Pass continue to see gusts between 40-55 mph with areas gusting as high as 88 mph along elevated terrain at the exit of the pass. These are expected to be the strongest gusts across the region for what is expected to be a prolonged weak Santa Ana Wind event through at least Monday. The 700-500 mb northwesterly winds will move eastward tonight along with the jet stream, making the surface pressure gradient the sole driver of the offshsore flow and bringing us down to weak but elevated Santa Ana Wind levels. The CW3E West WRF keeps us above 60% chances for weak Santa Ana Winds Saturday through at least next Wednesday. During this period, expect periods of elevated north/northeast winds sustained at 15-25 mph in the wind prone lowland areas with gusts 25-40 mph. For the coastal foothills and mountains, expect periods of winds sustained at 25-40 mph with gusts 50-65 mph. Winds and gusts may tick down a few mph mid-week as the surface gradient between the Great Basin and Southern California weakens a bit but remain offshore indefinently until a greater pattern change occurs.
As long as the offshore flow presists, relative humidity will remain low. Daytime RH drops into the 10-20% range this afternoon and Saturday afternoon and continue to drop into the 20-30% range into next week, with overnight recoveries capped at only 35-40% in the mountains. Fire danger will be elevated as a result although limited as the fuel moisture levels are high from recent rains.
Temperatures today are slightly below average, in the low to mid 60s in the lowlands. Temperatures climb 2-5 degrees F each day from today through Wednesday as a very longwave ridge slowly develops across the Western US and Northeast Pacific. WPC model clusters show the ridge likely centering off the Pacific Northwest though upper heights will increase as a result well into northern Mexico. With daytime heating, temperatures are likely (80% chance) to reach above 80 degrees in the valleys next Wednesday and Thursday. Next Friday and beyond, there is moderate to high confidence that the ridge remains strong off of British Columbia, although there are model solutions suggesting the possibility for an upper low to form near or retrograte into the southwest US, which could at the miinimum cool our temperatures back closer to average.
Moderate to locally strong Santa Ana winds will continue along the coastal mountain slopes, foothills, and into the valleys through Sunday. Periods of weaker Santa Ana winds will continue beyond that. Patchy frost is expected this morning in wind sheltered valley locations. A warming trend develops this weekend, with temperatures peaking around the middle of next week.
For extreme southwestern California including Orange, San Diego, western Riverside and southwestern San Bernardino counties,
, Updated Aviation and Marine sections,
In Orange County, Northeast wind gusts between 25-45 mph are being observed from the Santa Ana Mountain foothills down to the coast locally. Gusts of 55-65 mph are seen in the southwest facing canyons, locally up to 76 mph in Fremont Canyon. Areas south of the Cajon Pass continue to see gusts between 40-55 mph with areas gusting as high as 88 mph along elevated terrain at the exit of the pass. These are expected to be the strongest gusts across the region for what is expected to be a prolonged weak Santa Ana Wind event through at least Monday. The 700-500 mb northwesterly winds will move eastward tonight along with the jet stream, making the surface pressure gradient the sole driver of the offshsore flow and bringing us down to weak but elevated Santa Ana Wind levels. The CW3E West WRF keeps us above 60% chances for weak Santa Ana Winds Saturday through at least next Wednesday. During this period, expect periods of elevated north/northeast winds sustained at 15-25 mph in the wind prone lowland areas with gusts 25-40 mph. For the coastal foothills and mountains, expect periods of winds sustained at 25-40 mph with gusts 50-65 mph. Winds and gusts may tick down a few mph mid-week as the surface gradient between the Great Basin and Southern California weakens a bit but remain offshore indefinently until a greater pattern change occurs.
As long as the offshore flow presists, relative humidity will remain low. Daytime RH drops into the 10-20% range this afternoon and Saturday afternoon and continue to drop into the 20-30% range into next week, with overnight recoveries capped at only 35-40% in the mountains. Fire danger will be elevated as a result although limited as the fuel moisture levels are high from recent rains.
Temperatures today are slightly below average, in the low to mid 60s in the lowlands. Temperatures climb 2-5 degrees F each day from today through Wednesday as a very longwave ridge slowly develops across the Western US and Northeast Pacific. Wpc model clusters show the ridge likely centering off the Pacific Northwest though upper heights will increase as a result well into northern Mexico. With daytime heating, temperatures are likely (80% chance) to reach above 80 degrees in the valleys next Wednesday and Thursday. Next Friday and beyond, there is moderate to high confidence that the ridge remains strong off of British Columbia, although there are model solutions suggesting the possibility for an upper low to form near or retrograte into the southwest US, which could at the miinimum cool our temperatures back closer to average.
092130z, Coast/Valleys/Mountains, Mostly clear skies prevailing. Northeast and east winds gusting 35-50 kts along coastal slopes mostly north of San Diego County. Gusts 25-35 kts through the Inland Empire and into inland Orange County. including VCTY KONT/KSNA. expanding in coverage in more of San Diego County and more of the inland valleys after 03Z Sat. Periods of LLWS with MOD UDDFS downwind of coastal slopes (i.e. KONT, KSNA, KSBD). Wind pattern continues through much of Saturday.
Deserts, VFR conditions through the period. Strong northeast wind gusts staying mostly confined to mountain slopes, with winds generally below 20 kts.
Northeast to east winds will occasionally gust to 20 to 25 knots through this weekend. Otherwise, no hazardous marine conditions expected through Tuesday night.
Ca, Wind Advisory until 1 PM PST Sunday for Orange County Inland Areas-Riverside County Mountains-San Bernardino and Riverside County Valleys-The Inland Empire-San Diego County Mountains-San Diego County Valleys-San Gorgonio Pass near Banning-Santa Ana Mountains and Foothills.
High Wind Warning until 1 PM PST Sunday for San Bernardino County Mountains.
PZ, None.
