Dry and warmer weather through the weekend as gusty Santa Ana winds continue across the mountains into the inland valleys as an area of low pressure nears the region. This low pressure system will move southward into northern Mexico and will bring a small chance for light rain over San Diego County by late Sunday into Monday. Temperatures drop a little for Monday and Tuesday then high pressure will move over the region for much of next week, bringing dry and warmer weather.
For extreme southwestern California including Orange, San Diego, western Riverside and southwestern San Bernardino counties,
, New Aviation and Marine Discussion for the 18z TAF package,
This morning, a few mid and high clouds are moving from northeast to southwest across Socal in the northeast flow aloft around a closed upper low over the Lower Colorado River Valley. Surface pressure gradients are offshore and trending stronger. The combination of offshore pressure gradients and northeast flow aloft is enough to produce northeast winds gusting as high as 53 mph in the windiest locations this past hour.
The closed upper low will continue to migrate to the southwest, reaching a position off the central coast of Baja on Sunday. The Santa Ana winds will likely peak later today, producing strong northeast to east winds gusting mostly 40 to 50 mph with isolated gusts to 65 mph in the favored locations before gradually weakening through Monday. Socal can expect dry and warmer weather today and Sunday. Sunday will likely be the warmer day with daytime high temperatures reaching the mid 80s in the valleys and coastal areas, and the upper 80s in the low deserts.
The upper low will remain to our south through Monday and could bring some moisture from the sub-tropics into SoCal with the return flow on the north side of the low. This will bring a slight chance for light showers from late Sunday night through Monday, mostly to the mountains of San Diego County but light showers could also develop over the low deserts, inland valleys and southern portions of the Riverside County mountains. Rainfall totals are unlikely to exceed 0.10 inch
The closed upper low will begin to move northeast late Monday, reaching the New Mexico as an open wave by late Tuesday. The return of onshore flow and the marine layer will bring lower temperatures for Tuesday, especially west of the mtns, along with areas of coastal low clouds and fog during the nights and mornings.
For Wednesday through the end of the week, a ridge of high pressure building over the west coast will bring a return of unseasonably warm weather. Thursday and Friday will likely be the warmest days with temperatures reaching the low 90s in the inland valleys, the upper 70s to mid 80 in the coastal areas, the 70s in the mtns, the low 80s in the high deserts and the upper 90s in the low deserts.
071845z. Coast/Valleys/Coastal Slopes, VFR conditions expected through the TAF period. Strong NE winds currently gusting 25-40 kts through foothills and valleys with gusts up to 50 kts along coastal slopes and through passes. Winds will taper some this afternoon, but remain elevated through much of the coastal basin. Winds restrengthen along the coastal slopes and adjacent foothills 03-06Z Sun with gusts 35-50 kts once again. Strong gusts will become more infrequent overnight in the valleys, but winds will remain strong aloft resulting in areas of LLWS (including KSNA). This excludes areas downwind of Cajon Pass (i.e. KONT) where surface gusts should remain strong through the night.
Current water vapor satellite shows mountain waves present across most of the area. Moderate to strong up/downdrafts can be expected west of the mountains through the TAF period.
Deserts/Desert Slopes, VFR conditions expected through the TAF period. Elevated northeasterly winds this afternoon with gusts 20-30 kts in most areas (KPSP may occasionally gust 30-35kts before 00Z Sun). Moderate to strong up/downdrafts through this evening, especially in the Coachella Valley. Winds slowly diminish Saturday night into Sunday morning. Winds remain northeasterly through Sunday, but gusts should remain below 20 kts for most desert locations after 12Z.
Intermittent gusts near 20 knots possible in the outer coastal waters near San Clemente Island through the early afternoon. Winds turn out of the south Sunday evening with gusts nearing 20 knots again, primarily for the inner coastal waters. Otherwise, no additional hazardous marine conditions are expected through Thursday.
Ca, Wind Advisory until 5 PM PST Sunday for Orange County Inland Areas-Riverside County Mountains-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.
