Recent meteorological diagrams reveal the alarming rise of heat domes over the continental United States, raising concerns as climate patterns shift. According to NOAA, these heat domes form when high pressure in the mid-atmosphere acts like a cap, trapping heat at the Earth’s surface.
The longevity of these heat domes is closely tied to the behavior of the jet stream, a fast-moving band of winds located about 30,000 feet above sea level. The jet stream typically flows from west to east, influenced by temperature differences between warm tropical air and cold polar air. However, its meandering path can significantly affect weather patterns.
Jet Stream’s Impact on Weather
As the jet stream meanders, it creates areas of high (H) and low (L) pressure, influencing weather across the U.S. Ridges in the jet stream lead to high-pressure systems that can cause heat to build up, while troughs can introduce cooler, stormier conditions. Typically, these waves pass through the continental U.S. every three to five days, but when they stagnate, they can result in prolonged periods of extreme heat.
Climate Change’s Role
Climate change is exacerbating these patterns. The Arctic region is warming at a rate three times faster than the global average, a phenomenon known as Arctic amplification. This reduction in temperature differences between the equator and poles is slowing the jet stream, causing it to meander more significantly. As a result, larger high-pressure systems can become entrenched, leading to dangerous heat accumulation across North America, Europe, and Asia.
In July 2023, a stagnant polar jet stream trapped heat over parts of North America, creating hazardous temperature conditions. This year, multiple regions are experiencing simultaneous heat waves, highlighting the global implications of these atmospheric shifts.
The unpredictable behavior of the jet stream also contributes to extreme winter weather, including the southward intrusion of frigid polar air. These changes, driven by human-caused climate change, pose significant risks to public health, property, and ecosystems worldwide.
As we face an increasingly unpredictable climate, understanding the dynamics of heat domes and the jet stream is crucial for preparing for and mitigating the impacts of extreme weather events.