Gradual warming and dry weather through the end of the week with highs increasing to as much as 10 to 20 degrees above normal. High clouds and weak offshore flow expected through Tuesday, then weak onshore flow returns with increasing chances for marine low clouds later in the week.
For extreme southwestern California including Orange, San Diego, western Riverside and southwestern San Bernardino counties,
, New Aviation Discussion for the 12Z TAF Package,
A blocking high pressure ridge will slowly build throughout this upcoming week just west of Baja California, bringing warm and quiet weather to the region. High temperatures today are expected to reach into the mid-70s for inland areas and right around 70F at the coast. Highs will be most noticeably milder in the mountains as temperatures climb from the 40s and lower 50s yesterday to the 50s and lower 60s this afternoon. Highs bump up around 5 degrees region- wide Monday and plateau around the low-70s to low-80s throughout the coastal basin through Wednesday, with about a 50/50 chance for highs above 80F for inland areas each of these days. Meanwhile, high temperatures in the lower deserts continue to surge into mid- week from the upper 70s today to likely (70-90%) reaching 90F and above by Wednesday.
Models continue to converge on the idea of the ridge axis expanding northward lake week, allowing high temperatures to continue to climb, peaking Friday or Saturday, into the mid-70s at the coast, mid-80s inland and mid-90s for the lower deserts - around 10 to 20 degrees F above average. Even mountain areas above 6,000 feet - just having recently received feet of snow - have the potential (30-50%) of reaching above 70 degrees by late week.
Beyond, most WPC model clusters show the ridge weakening or moving eastward allowing for temperatures to cool, although there is uncertainty whether the pattern change will allow for the return of precipitation or just cooler temperatures.
Winds will generally be light and variable throughout next week with some weak offshore flow over the west-facing mountain slopes/passes through Monday evening. As a result, daytime RH values will drop to 10-20% inland through Tuesday until weak onshore flow mid-week brings min-RH's to the 30-40% range for inland areas despite the increasing daytime temperatures.
There is significant uncertainty on the status of the marine layer, with increasing chances for the return of low clouds Wednesday with the return of onshore flow.
221130z, VFR and mostly clear skies expected through the TAF period. FEW-SCT cirrus AOA 25,000ft MSL persisting into Sunday evening.
No marine hazards are expected through Friday.
Ca, None. PZ, None.
