Updated

Updated · Yahoo! Voices · Aug 2

Western Heat Dome Puts 45 Million Under Alerts as Phoenix and Las Vegas Near 114F

Updated

Updated · Yahoo! Voices · Aug 2

Western Heat Dome Puts 45 Million Under Alerts as Phoenix and Las Vegas Near 114F

Q: How is a distant tropical storm secretly fueling both extreme inland wildfire risks and dangerous coastal erosion across Southern California?

A distant Tropical Storm Genevieve is affecting Southern California indirectly, by pumping moisture and ocean energy into an already dangerous heat pattern even though the storm itself is staying far offshore. Inland, forecasters say Genevieve’s lingering tropical humidity is mixing with unusually warm Pacific waters and a strong high-pressure ridge over the Southwest. That combination makes the air feel hotter, slows overnight cooling, and dries vegetation more efficiently over time because the prolonged heat stress keeps fuels at critical levels. Fire officials and meteorologists note that extreme heat, poor nighttime humidity recovery in inland and mountain areas, and very dry brush sharply raise the risk that any spark could spread fast into a large wildfire. Along the coast, the same storm is sending a long-period south swell toward Southern California. Even without landfall, powerful tropical cyclones can radiate wave energy hundreds of miles away. That swell is producing 4- to 8-foot surf, dangerous rip currents, and in some spots coastal flooding and beach erosion. Repeated wave தாக்க against beaches and bluffs strips sand away and can undercut vulnerable shoreline areas. So Genevieve is working through two separate pathways at once: through the atmosphere, by helping sustain hotter and more humid conditions that worsen inland fire danger, and through the ocean, by sending swell that increases surf hazards and erosion along the coast.

3 articles · Updated · Yahoo! Voices · Aug 2

About 45 million people across the West were under heat alerts Sunday as an unusually intense heat dome pushed dangerous temperatures from California and Arizona to the Canadian border.
Forecast highs were set to reach 114F in Phoenix and Las Vegas, with dozens of records at risk from California to Montana and triple-digit heat spreading into the Plains and northern Rockies.
The National Weather Service warned of major to extreme heat risk across much of the region, with Los Angeles, Phoenix and Las Vegas opening cooling centers as hot nights in the upper 80s and low 90s raise illness risk.
Critical fire weather covered much of Montana and parts of Idaho and Wyoming, while eastern Washington and Oregon faced elevated danger, smoke alerts and Spokane County evacuations tied to the Old Trails Fire.
Extreme heat is the deadliest US weather hazard, and forecasters say repeated heat domes this summer fit a broader pattern of more intense, longer-lasting heat linked to climate change.