Ation and Marine Sections,
An elongated ridge of high pressure is draped over the West Coast as high clouds begin to thin over Southern California. Offshore flow persists with winds along the coastal slopes and valleys mainly near 20-30 MPH, locally higher in passes near 40 MPH. The pressure gradient will begin to ease later today through Sunday, where Santa Ana winds will become minimal and confined to mainly foothills/passes. Temperatures will remain well above average this weekend with highs reaching into the 80s for valleys west of the mountains into the lower deserts, while 50s/60s remain over the higher elevations.
As pressure heights fall by Sunday into Monday, subtle cooling will occur for areas near the coast with highs around 5 degrees cooler, while still remaining warm inland. As high pressure overhead weakens, the marine layer will begin to build in deeper. This will lead to a better chance of fog near the coast by Monday morning, some of which could be dense for the morning commute. A weak impulse of offshore winds may occur on Tuesday, with more elevated wind gusts near 30 MPH at times in the passes. Confidence is low if this will keep the completely offshore, so confidence remains low on any development at the coast.
High pressure will remain over the region through the middle of next week, though weaker. An area of low pressure will move closer to the region by this time, aiding in greater onshore flow and a slow cooling trend. This will bring a few degrees of cooling each day into Friday, where highs will mainly be in the 60s or lower 70s for all lower elevations. Models continue to struggle on exactly where this area of low pressure will go, though a general trend toward a more zonal pattern is indicated. Ensemble members do show greater chances for wet weather sometime by next Friday or next weekend. Rain chances for now remain near or below 20 percent with low confidence on when or if we see any rainfall from this weather system.
Santa Ana winds will continue to decrease over the weekend with warm weather continuing. High temperatures as much as 10 to 15 degrees above average for the valleys will continue through Sunday followed be a gradual cooling trend through the end of next week. The marine layer will begin to rebuild by the first half of next week, leading to better chances for clouds and fog near the coast. An area of low pressure will move closer to our region, bringing low chances for precipitation by late next week.
For extreme southwestern California including Orange, San Diego, western Riverside and southwestern San Bernardino counties,
, Updated Aviation and Marine Sections,
An elongated ridge of high pressure is draped over the West Coast as high clouds begin to thin over Southern California. Offshore flow persists with winds along the coastal slopes and valleys mainly near 20-30 MPH, locally higher in passes near 40 MPH. The pressure gradient will begin to ease later today through Sunday, where Santa Ana winds will become minimal and confined to mainly foothills/passes. Temperatures will remain well above average this weekend with highs reaching into the 80s for valleys west of the mountains into the lower deserts, while 50s/60s remain over the higher elevations.
As pressure heights fall by Sunday into Monday, subtle cooling will occur for areas near the coast with highs around 5 degrees cooler, while still remaining warm inland. As high pressure overhead weakens, the marine layer will begin to build in deeper. This will lead to a better chance of fog near the coast by Monday morning, some of which could be dense for the morning commute. A weak impulse of offshore winds may occur on Tuesday, with more elevated wind gusts near 30 MPH at times in the passes. Confidence is low if this will keep the completely offshore, so confidence remains low on any development at the coast.
High pressure will remain over the region through the middle of next week, though weaker. An area of low pressure will move closer to the region by this time, aiding in greater onshore flow and a slow cooling trend. This will bring a few degrees of cooling each day into Friday, where highs will mainly be in the 60s or lower 70s for all lower elevations. Models continue to struggle on exactly where this area of low pressure will go, though a general trend toward a more zonal pattern is indicated. Ensemble members do show greater chances for wet weather sometime by next Friday or next weekend. Rain chances for now remain near or below 20 percent with low confidence on when or if we see any rainfall from this weather system.
172130z, SCT high clouds and VFR conditions prevail through the majority of the region through Sunday afternoon. Offshore winds will be elevated along coastal slopes and into adjacent foothills/parts of the Inland Empire through 06Z Sun with intermittent gusts 20-35 kts. Gusts locally to 40 kts through and just below wind prone passes, including the Cajon Pass. Winds decrease late tonight. Isolated patches of dense fog are possible along the immediate coast 06-10Z Sun, but are unlikely (10% chance or less) to impact any TAF sites.
Localized areas of fog in the coastal waters reducing visibility to 1 SM or less are possible tonight through early Sunday morning. Otherwise, no hazardous marine conditions are expected through Wednesday.
Ca, None. PZ, None.
