Southwest Heat Dome Also Triggers Flash Flood Risk Across Rockies and Plains

A heat dome bringing 110–115°F highs to 45 million people across the southwestern US through late August 2026 is also driving monsoonal moisture into the southern Rockies and Plains, the NWS forecasts. The result is a compound hazard: Extreme HeatRisk alongside severe thunderstorms and isolated flash flooding. A heat dome traps hot air under high pressure; its periphery feeds convective instability.