peaked Southwest U.S. heatwave into August, with elevated humidity persisting in SoCal due to very warm ocean

Key Points:

• The Pacific Ocean along the Southern California coast is experiencing record-warm near-shore sea surface temperatures driven by a strong El Niño event, leading to consistently above-average coastal temperatures and unusually high humidity levels that amplify heat stress on residents.
• A double-peaked extreme heatwave is forecast for late July into August across the Southwest US, featuring record-breaking atmospheric ridge heights and potentially record-setting surface temperatures, especially in the Great Basin, Central Rockies, and interior Southern California.
• Hurricane Genevieve, despite weakening, is expected to enhance the Southwest ridge and heatwave through latent heat release, contributing to record-high atmospheric heights and intensifying the heat event and coastal surf impacts.
• The prolonged warm and humid conditions, combined with accelerated vegetation drying, are increasing wildfire risks across California and the Pacific Northwest, with potential for plume-driven fires in Southern California and sustained fire activity fueled by dry winds in the Northern Rockies and Cascades.
• Weather West plans to reduce reliance on advertising by expanding direct support options, maintaining free access to all content, and introducing biannual "Ask Me Anything" livestreams as a supporter perk; a YouTube livestream discussing the heatwave, Hurricane Genevieve, and fire weather is scheduled for July 29.