Showers will end early this morning. This will be followed by dry and warmer weather into the weekend with strengthening Santa Ana winds for Thursday and Friday. Cooling will begin to spread into the coast and valleys during the weekend while the mountains and deserts slowly warm.
For extreme southwestern California including Orange, San Diego, western Riverside and southwestern San Bernardino counties,
, UPDATED AVIATION DISCUSSION,
(today through Thursday), The center of a closed low pressure system will move southward into southern Nevada today, then move to the east and near the four corners on Wednesday. A cutoff low pressure system forming on Thursday will be centered over southern California into northern Baja.
Through sunrise this morning, the flow aloft will turn from westerly to northwesterly to northerly. Light showers over the coastal waters moving inland into San Diego County will transition to moving not as far inland and mostly into southern sections of the county, clearing from southwestern San Diego County around sunrise.
Dry weather with warming will then follow through Thursday. High temperatures for today will warm 5 to 10 degrees for the mountains and Inland Empire and locally 15 degrees for some mountain locations. That warming will continue on Wednesday with high temperatures another 5 to 10 degrees warmer. On Thursday, high temperatures will warm a few to around 5 degrees for the deserts into the mountains and as much as 5 to 10 degrees for the coast into the western valleys.
High temperatures on Thursday will be around 5 degrees below average for the deserts into the mountains with coastal areas 8 to 12 degrees above average. High temperatures on Thursday will be mostly in the 80s for the beaches. Elsewhere for the coast and valleys, high temperatures will range from around 80 for the far inland valleys to the mid 80s to lower 90s for inland coastal areas into the far western valleys. There will be areas of Moderate HeatRisk for coastal areas on Thursday.
The lower level flow will turn to north to northeast on Wednesday and northeast to east on Thursday with coverage and strength of the winds increasing on Thursday. Santa Ana winds will gust to 20 to 30 mph for the mountains on Wednesday with winds along and below the coastal slopes of the mountains gusting to 35 to 45 mph on Thursday.
(Friday through Monday), The stronger offshore flow will continue into Friday with ECMWF ensemble output still showing the strongest offshore winds at Campo on Friday, then not as strong on Saturday. Winds on Friday could gusts to 45 to 55 mph with easterly Santa Ana winds extending to near the coast in San Diego County.
High temperatures will continue to warm on Friday, then cool a few to around 5 degrees on Saturday. High temperatures on Friday for the beaches will be in the mid 80s to lower 90s. Elsewhere for the coast and valleys, high temperatures will range from the upper 70s to mid 80s for the far inland valleys to the upper 80s to mid 90s for inland coastal areas into the far western valleys. Moderate to locally Major HeatRisk is expected for coastal areas into the western valleys for Friday, then mostly Moderate HeatRisk just for coastal areas on Saturday.
For Sunday and Monday, cooling will spread inland into the coast and valleys while the mountains and deserts warm. High temperatures for next Monday will be mostly a few to around 5 degrees above average to 5 to 10 degrees above average for San Diego County coastal areas. On Monday, high temperatures will range from the mid 70s to lower 80s near the coast to the 80s for the Inland Empire with the lower deserts in the lower 90s.
That cutoff low pressure system could transport some tropical northward into the area by the weekend into early next week. While precipitation chances will remain low and be mainly for the lower deserts eastward into Arizona, it should put a floor on any decrease in humidity with the offshore flow with lowest humidity for inland coastal areas into the valleys of 20 to 30 percent on Thursday and Friday and 25 to 35 percent on Saturday.
131130z, BKN clouds based 3500-6000 feet MSL through 17Z in western San Diego County, with local terrain obscuration in foothills. SCT clouds north and clearing from north to south through 17Z. Mostly clear thereafter, except for SCT-BKN cumulus based at 8-10 kft over all mountains 18-00Z. North winds gusting 25-30 kts after 20Z in San Bernardino Mountain foothills and locally into northeast Inland Empire through 03Z.
No hazardous marine conditions are expected through Saturday, except isolated northeast wind gusts could briefly exceed 20 kts Thursday afternoon through Friday morning.
A prevailing southerly swell will continue today, generating surf 3- 5 feet with local sets to 7 feet, along with strong rip currents. Late morning high tides near 7 feet will continue, producing minor coastal flooding. Check the Coastal Flood Advisory for details.
Ca, Coastal Flood Advisory until 2 PM PDT this afternoon for Orange County Coastal Areas-San Diego County Coastal Areas.
PZ, None.
