Monsoonal moisture will maintain a slight chance of afternoon showers and thunderstorms for the mountains and deserts through Tuesday. A warming trend will continue through Thursday with widespread major to extreme HeatRisk for the lower deserts, valleys, and inland Orange County. Widespread moderate or greater HeatRisk except for mountain elevations above 7000 feet is expected to continue through next Saturday.
For extreme southwestern California including Orange, San Diego, western Riverside and southwestern San Bernardino counties,
, UPDATED AVIATION DISCUSSION,
(today through Wednesday), There will be a warming trend through Thursday with high temperatures for today around 5 degrees above average for the mountains and deserts and 5 to 10 degrees above average for the coast and valleys. High temperatures for today will range from around 80 near the coast to the upper 90s to 106 for the Inland Empire with the lower deserts around 110.
Precipitable water values will peak today and Tuesday, then decrease through next weekend. There is a slight chance of showers and thunderstorms for this afternoon and Tuesday afternoon for the mountains and deserts.
(Thursday through Sunday), The warming trend will continue through Thursday with high temperatures on Thursday around 10 degrees above average for the mountains and deserts to 10 to 15 degrees above average for the coast and valleys. High temperatures on Thursday will range from the 80s near the coast to 105 to 110 for the Inland Empire with 112 to 116 for the lower deserts. Low temperatures on Thursday will be as much as 10 to 15 degrees above average for the mountains and inland valleys. Low temperatures for the coast and valleys will be mostly in the 70s. There could be a large number of records for warmest low temperatures tied or broken on Thursday and Friday.
Temperatures will gradually cool for Friday through Sunday with high temperatures for Sunday around 5 degrees above average. High temperatures on Sunday will range from around 80 near the coast to the mid 90s to 103 for the Inland Empire with 108 to 112 for the lower deserts.
The HeatRisk is expected to peak on Thursday with major to extreme HeatRisk for the lower deserts, valleys, inland Orange County, and the Santa Ana Mountains with moderate to major HeatRisk elsewhere expected for the mountains above 7000 feet.
241130z, Coast, Patchy low clouds based around 300-800 feet MSL with vis reduced 0-5SM will continue temporarily through 16Z. Even fewer and patchier low clouds expected overnight into Tuesday.
Mountains/Deserts, Building cumulus based around 9000 feet MSL leading to CB clouds with tops to 45000 feet and SCT TSRA over mountains and locally into adjacent deserts 19-02Z. Any TS could produce gusty, erratic winds.
Otherwise, SCT to locally BKN clouds AOA 20000 feet MSL becoming mostly clear after 03Z.
No hazardous marine conditions are expected through Friday.
A 4-5 foot southerly swell (from 170 degrees) at 13-15 seconds will move into the area Wednesday and Thursday, leading to elevated surf for the south facing beaches of northern San Diego County and Orange County. Breaking waves of 4 to 6 feet expected, sets up to 8 feet possible at beaches that face due south. Surf gradually subsides on Friday.
Ca, Heat Advisory from 10 AM Tuesday to 8 PM PDT Friday for Orange County Coastal Areas-San Diego County Coastal Areas.
Heat Advisory until 10 AM PDT Tuesday for Orange County Inland Areas-San Bernardino and Riverside County Valleys-The Inland Empire-San Diego County Mountains-San Diego County Valleys-Santa Ana Mountains and Foothills.
Extreme Heat Warning from 10 AM Tuesday to 8 PM PDT Friday for Apple and Lucerne Valleys-Orange County Inland Areas-San Bernardino and Riverside County Valleys-The Inland Empire- San Diego County Mountains-San Diego County Valleys-Santa Ana Mountains and Foothills.
Heat Advisory until 8 PM PDT Friday for Riverside County Mountains-San Bernardino County Mountains.
Extreme Heat Warning until 8 PM PDT Friday for Coachella Valley- San Diego County Deserts-San Gorgonio Pass near Banning.
PZ, None.
