Southwest Heat Wave Threatens Records, Raises Wildfire and Water Risks

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A strengthening heat dome is driving temperatures well above seasonal averages across the southwestern United States, with potential implications extending beyond immediate discomfort. From record-challenging highs in Los Angeles and Phoenix to the accelerating melt of Sierra Nevada snowpack and the potential for a rapid decline in water levels, the early-season heat is raising concerns about wildfire risk and long-term water security.

Why it matters

The unusual warmth poses a direct threat to the spectacular superbloom currently unfolding in Death Valley National Park and the temporary Lake Manly that has formed there. The rapid snowmelt could also lead to earlier peak flows and potentially lower water levels later in the spring and summer, particularly in the Colorado Basin where mountain snowpack has been below average in recent years. The combination of surging heat and dry conditions is increasing the risk of wildfire ignition across the region.

The details

Triple-digit temperatures are forecast for Death Valley next week, potentially causing flowers to wilt and accelerating the evaporation of the temporary Lake Manly. Los Angeles experienced a record high near 90 degrees Fahrenheit on Friday, but temperatures are expected to climb even higher this week, potentially approaching record highs dating back to 1914. Las Vegas is also bracing for unusually warm conditions, with temperatures nearing 100 degrees – a first for May. Phoenix could see multiple days above 100 degrees, rivaling records set in 1988. Across the Sierra Nevada and the Rockies, temperatures may reach 70 degrees at elevations around 7,000 feet, accelerating snowmelt.

• On Friday, Los Angeles experienced a record high near 90 degrees Fahrenheit.
• Next week, triple-digit temperatures are forecast for Death Valley.