Weakening Santa Ana winds will continue into this morning with the stronger gusts mostly 35 mph or less. Inland areas will remain warm and very dry today while high temperatures for coastal areas cool around 5 degrees. For Friday through Sunday, onshore flow will spread cooling inland. Monday and Tuesday will be drier inland with north flow aloft. For the middle part of next week, another low pressure system from the north may move southward along the West Coast with a chance for precipitation around Wednesday and Thursday.
For extreme southwestern California including Orange, San Diego, western Riverside and southwestern San Bernardino counties,
.Morning Update,
High clouds will continue to move into the region from the south today. Santa Ana winds are gusting near 25-35 MPH this morning. These winds will begin to weaken this afternoon, becoming more localized to area mountain passes. The light offshore flow pattern will contribute to another warmer day out there with some valley locations west of the mountains surpassing 80 degrees once again, with pleasant and cooler weather up in the mountains with highs in the upper 50s and 60s. We hope you have a wonderful Thanksgiving!
.Previous Discussion (437 AM Thursday),
(today through Saturday), The latest NKX sounding shows a very dry atmosphere below 500 mb with a moist layer between 400 and 250 mb. High clouds from a weak low pressure system well off the Baja coast will move across the area today with the clouds decreasing tonight.
Weak offshore flow continues early this morning with the stronger northeast to east winds along and below the coastal slopes of the mountains mostly gusting to 35 mph or less. The atmosphere just above the surface is quite warm. Where mixing from the offshore winds is occurring, temperatures are still in the lower to mid 70s as of 4:30 AM with relative humidity around 10 to 25 percent.
High temperatures for today for the coast into the western valleys will cool around 5 degrees. High temperatures for the inland valleys will be around 8 to 12 degrees above average with high temperatures in the lower 80s and locally into the mid 80s. High temperatures for the coast and valleys will cool another 5 degrees on Friday with cooling spreading into the mountains and deserts on Saturday. High temperatures on Saturday will still be around 5 degrees above average for inland areas with high temperatures ranging from the mid 60s near the coast to the upper 60s to mid 70s for the valleys with the mid to upper 70s for the lower deserts.
Patchy low clouds and locally dense fog may return along the coast for Friday night into Saturday morning.
(Sunday through Wednesday), A low pressure system from the north moving through the Pacific Northwest on Saturday and into the Great Basin on Sunday will remain on a track that is inland enough to limit entrainment of Pacific moisture and resulting chances for precipitation for southwestern California. Chances for measurable precipitation will remain below 10 percent through Tuesday.
The cooling trend will continue through Sunday with drier north flow on Monday bringing slight warming. For the middle of next week, another low pressure system moving southward along the West Coast may bring a chance of precipitation for southern California for Wednesday and Thursday. There are both model timing and track differences with this system.
271630z. Coasts/Valleys, VFR prevailing with SCT-BKN high clouds AOA 20,000ft MSL. Patchy low clouds develop offshore tonight, with a low to moderate chance (25-45%) of brief impacts at KSAN with bases around 500-800ft MSL and a low chance at KSNA or KCRQ (25-30%). Highest chances for impacts will be between 13-17z Fri. Localized VIS reductions down to 3-5SM possible during this time as well, with possibly lower for coastal terrain. Any clouds that made it ashore will filter back to the coast by 18-19z.
.Mountains/Deserts, VFR conditions expected through the TAF period. Gusty winds out of the E to NE at 25-35 kt in mountain passes through 20Z today. Areas of LLWS/low-level turbulence along foothills/coastal mountain slopes are expected through late this morning. High clouds SCT-BKN AOA 20,000ft MSL prevailing through today.
No hazardous marine conditions are expected through Tuesday.
Ca, None. PZ, None.
