DISCUSSION
FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES...

Almost cloud free along beaches with small patches left and also clear inland with the air mass drying from north to south with precipitable water values decreasing further. There was an outflow that moved into the Coachella Valley early this morning and raised dewpoints but convection is not expected today though cumulus will form especially San Diego mountain desert slopes closer to the remaining monsoon moisture of 1.4 inch values.
Notably stronger drier of under 1 inch precipitable water air mass now over San Gabriel and San Bernardino mountains per Storm Prediction analysis. Today is nearly as hot as yesterday for inland areas with air mass of 25-26C on the coast but up to 31 to 32C for inland deserts, so we still have moderate heatrisk in the Inland Empire and areas of major in the lower deserts. 109F at Palm Springs as of noon and same as yesterday.

We finally have cooling of air mass for Saturday (22-28C at 850 mb level), in the wake of the disturbance that tracks across northern California. There is also a better push of more organized low clouds and marine air into the valleys. Fire weather conditions deteriorate because of drier air and increasing onshore flow for all deserts and the mountains with the peak of the westerly winds on Saturday. The coolest day for most areas will be Sunday.

Weather pattern warms next week but still considerable uncertainty as potential upper level wave arrives during midweek from Mexico on the backside of the heat dome rebuilding over the Great Basin and 4-corners region. This could bring back monsoon moisture as well for late week.

AVIATION
261930
Coast
Low clouds with more uniform coverage will move ashore around 04-05Z and eventually cover coastal areas and western valleys overnight. Bases will be around 800-1200 feet MSL and local vis reduced 1-5SM on higher coastal terrain and western valleys.
Scatter out Saturday by 15-18Z.

Mountains/Deserts...Westerly winds gusting 25-35 kt gradually tapering off overnight through mountain passes into adjacent deserts. MOD up/downdrafts in lee of mountains.

MARINE
No hazardous marine conditions are expected through Wednesday.

FIRE WEATHER
Elevated fire weather conditions Friday and Saturday afternoons due to the drier air, lower humidity, and increase afternoon and evening onshore west winds for the mountains and all deserts, especially the High Desert.

CLIMATE
4th time this year Palm Springs has hit 120F. The record is 5 set in 2020 and 2021.

SGX WATCHES/WARNINGS/ADVISORIES
CA...Excessive Heat Warning until 8 PM PDT this evening for Coachella Valley-San Diego County Deserts-San Gorgonio Pass Near Banning.

PZ...None.