Warm and dry conditions with periods of Santa Ana winds expected this week. The peak of the heat is expected to be mid-week. Patchy low clouds could develop overnight into Monday morning near the coast.
For extreme southwestern California including Orange, San Diego, western Riverside and southwestern San Bernardino counties,
.Evening Update,
A few areas of low clouds and fog continue to drift over parts of the coastal waters this evening. Very isolated spots of fog may occur near the coast through the early morning, but most areas are expected to stay clear overnight.
Though the weekend has ended, the warm weather has not! The forecast remains on track to see high temperatures 10 to 20 degrees above normal for the upcoming week. Tuesday will be the warmest day for valleys west of the mountains with chances near 20% to 60% to see highs at or above 85 degrees. The ridge has a good chance to break down some by next weekend, leading to a slow cooling trend.
.Previous Discussion (141 PM Sunday),
For tonight into Monday morning there is a 10 to 20 percent chance of patchy low clouds and dense fog developing along the coast, with slightly higher chances of dense fog developing over the coastal waters. Mostly clear skies will prevail from Monday afternoon through the middle of the week due to periods of weak to moderate Santa Ana winds.
A persistent surface high pressure over the Great Basin will remain in place through Saturday. This will bring weak to locally moderate Santa Ana winds to the area. With no upper level support, the strongest winds will remain confined to coastal mountain slopes, foothills, and below passes. The strongest winds are expected on Tuesday with gusts 25 to 45 mph. A secondary peak in winds is expected on Friday. The airmass getting pushed into Southern California from the Great Basin will be on the drier side, with minimum afternoon relative humidity for inland areas falling to 10 to 20% each afternoon through Friday, bringing periods of elevated fire weather conditions.
An upper level ridge over the East Pacific will strengthen over the US West Coast through Tuesday, bringing an uptick in high temperatures. High temperatures on Tuesday will be 15 to 20 degrees above average. Widespread highs in the low to mid 80s are forecast across the inland coastal areas into the valleys as well as the low deserts. Weaker Santa Ana winds and a weakening in the upper level ridge will allow for minor cooling on Wednesday and Thursday mainly for coastal areas. The secondary uptick in Santa Ana winds on Friday is expected to bring additional warming to areas west of the mountains with high temperatures expected to run up to 20 degrees above average for inland areas. Nights and mornings will remain cool, especially in the wind-sheltered areas, minimizing any heat impacts. A few degrees of cooling is expected into next weekend as weak onshore flow returns, but temperatures will continue to run above average.
072100z, Clear skies and VFR prevail region-wide through Monday. 10-20% chance for very patchy fog/vis reductions developing within 5 miles of the coast overnight. Offshore E/NE winds gusting 25-35 kts to pick up through mountain passes and Santa Ana mountain coastal slopes after 13z Mon, clearing out any leftover fog near the coast.
Patchy dense fog this evening will continue to be isolated through early Monday morning. Visibility in fog 1 nautical mile or less.
Ca, None. PZ, None.
