Moderate to locally strong Santa Ana winds will continue along the coastal mountain slopes, foothills, and into the valleys through Monday. Periods of weaker Santa Ana winds will continue through the remainder of next week. A warming trend develops this weekend, with temperatures peaking around the middle of next week. Wednesday and Thursday will likely be the warmest days.
For extreme southwestern California including Orange, San Diego, western Riverside and southwestern San Bernardino counties,
Clear skies region-wide this morning as moderate easterly Santa Ana winds continue to funnel through west facing slopes and passes. The strongest upper level northerly winds have moved eastward and the gusts have reduced considerably in the past 24 hours over the Santa Ana and San Bernardino County foothills. Gusts are now 40-55 mph around the Cajon Pass and mostly below 40 mph though the Inland Empire and Orange County inland areas.
The surface pressure gradient between Southern California and areas a few hundred miles east and northeast of us remains strong, allowing for elevated winds to continue for the areas mentioned above as well as strong East winds over the San Diego County mountains. Gusts 50-65 mph and locally higher are expected for the San Diego County mountain western slopes near peaks and passes through early Monday. Winds reduce slightly thereafter but remain strong with periods of gusts to 50 mph remain possible through at least Wednesday, as easterly 700 mb winds remain robust. There is some uncertainty regarding the Santa Ana winds after Wednesday, although most model guidance suggests a continuation of the offshore flow. The CW3E WRF maintains weak to moderate northeast and east pressure gradients between SoCal and the interior through next Friday. Medium range models continue to highlight modest mid-level easterly flow over our region until at least next weekend.
Due to the abundance of dry air at the surface, nighttime temperatures will drop into the 30s in wind-sheltered valleys tonight and potentially Sunday night. At the same time, high temperatures will be increasing a few degrees each day through Wednesday. Lowland temperatures top out around 70 degrees today and are eventually forecast to top out around 80 degrees Wednesday afternoon.
WPC 500mb height clusters are in good agreement that the strong upper longwave ridge over the Pacific Northwest will continue to amplify northward. While the ridge axis will continue to be lined up along the west coast, SoCal may be far enough south enough to see heights come down slightly with an outside chance for an upper cutoff low to develop over northwest Mexico and bring down temperatures near average and enhance cloud cover. Nevertheless, there is moderate confidence for peak temperatures next week to occur Wednesday and Thursday, then cool off slightly into the weekend.
As long as the offshore flow persists, relative humidity will remain low. Daytime RH drops into the 10-20% range through at least Tuesday , with overnight recoveries capped at only 35-40% for most of the region. Fire danger will be elevated as a result although limited as the fuel moisture levels are high from recent rains.
101650z, Coast/Valleys/Mountains, Mostly clear skies prevailing. Northeast and east winds gusting generally 35-50 kts along coastal slopes. Gusts locally reaching 60 kts or higher along coastal slopes in San Diego County until 02Z Sat. Gusts 25-40 kts downwind of the Cajon/Banning passes in the Inland Empire and into parts of Inland Orange County and the San Diego Valleys. Winds picking back up and becoming more widespread after 16Z Sun to around that of this morning. Periods of LLWS and moderate up and downdrafts downwind of coastal slopes (i.e. KONT, KSNA, KSBD). Offshore wind pattern continues through the remainder of the weekend.
Deserts, VFR conditions through the period. Elevated northeast winds staying mostly confined to mountain slopes with gusts 20-30 kts.
Northeast to east winds will sporadically gust to 20 to 25 knots through this weekend. Otherwise, no hazardous marine conditions expected through Wednesday.
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 Valleys-Santa Ana Mountains and Foothills.
High Wind Warning until 1 PM PST Sunday for San Bernardino County Mountains-San Diego County Mountains-San Gorgonio Pass near Banning.
PZ, None.
