Dry and warm weather continues into Tuesday with increased Santa Ana winds across the mountains and western valleys. Cloudier skies will enter the region by Tuesday as low pressure systems across the Pacific move over our area this week. This will bring chances for periods of rain showers by New Year's Eve into this weekend.
For extreme southwestern California including Orange, San Diego, western Riverside and southwestern San Bernardino counties,
, New Aviation Discussion Below,
North and east winds continue to be gusty overnight with winds mainly 35-50 MPH across the coastal slopes and 25-35 MPH across the Inland Empire and foothills of Orange and San Diego counties. These Santa Ana winds are associated with a surface area of high pressure situated over the Great Basin of western Utah. The pressure gradient between this and our area will continue to strengthen into the morning and afternoon hours, where winds will become most widespread. By the afternoon, chances for wind gusts near 20 MPH increase for areas closer to the coast. Winds will become more localized Monday night with a slight resurgence on Tuesday morning for the mountains and western valleys with gusts 25-45+ MPH. This wind pattern will allow temperatures to also rise across the region today and Tuesday. The best chance to see highs over 75 degrees will be areas of East County in San Diego on Tuesday with around a 50-60% chance of occurrence.
Take in those clear blue skies today because you may not be seeing them much this week, ! An area of low pressure approximately 1,000 miles southwest of San Diego will begin to move northward Monday evening into Tuesday. Subtropical moisture associated with this system in the form of mid/high-level clouds will begin to overspread the area during this time. The temperature forecast will be a bit trickier with this as extensive cloud cover may limit peak daytime heating on Tuesday, though still fairly confident in seeing highs in the 70s west of the mountains and in the lower deserts late Tuesday morning/afternoon with the day being mainly dry.
As the system moves further north on Wednesday, chances for mainly light showers will increase throughout the day. Around New Year's Eve, chances for measurable rainfall increase near 60-80% along and west of the mountains to near 40-60% across the desert regions. There continues to be low confidence on exact rain amounts but there is increasing confidence the heaviest rain will fall sometime late Wednesday night into Thursday morning. Global models are beginning to agree on shower chances lowering by late Thursday into Friday as the system passes to the east and another low pressure system delays off the coast. Nbm chances for precip are near 50% at this time but would not be surprised if these lower some in the coming days' forecast as some areas may see very little to no rain during this time. The details about the low pressure system off the coast by late week still remain uncertain. Models show a fairly northerly track with this feature, so chances for the heaviest rainfall will be closer to the LA Basin by late Friday or Saturday.
For both of these events this week, subtropical moisture from the south and southwest will keep snow levels over 8,000 where most of our friends across the mountains will see only rain. Cooler air with a semi-active weather pattern remaining in place, may bring lower snow levels and continued chances for wet weather across SoCal by next weekend.
291030z, VFR conditions continue through the TAF period with FEW- SCT high clouds AOA 25,000ft. Gusty winds out of the north to northeast will continue to gradually strengthen this morning into the afternoon with wind gusts of 35-45kts for the coastal mountain slopes and mountain passes with 20-30kt gusts stretching below mountain passes into inland valleys. Localized areas of reduced VIS due to BLDU possible, especially near the mountains. Gusty northerly winds below Cajon pass could produce crosswinds on approach/takeoff within the Inland Empire along with 25-35 kts of low level wind shear. Widespread mod up/downdrafts expected, especially near mountains and mountain passes. Strong offshore winds prevail into through Tuesday morning.
No hazardous marine weather conditions expected through Saturday.
Ca, Wind Advisory until 1 PM PST Tuesday for San Bernardino 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.
PZ, None.
