A heat dome, also known as an "omega block" is a weather pattern characterized by an area of high pressure that remains stagnant over a specific region, trapping heat and preventing the formation of clouds. This results in abnormally high temperatures, which can lead to heat waves. Recently, the Pacific Northwest and some parts of Canada have experienced a "historic" heat wave as a result of this phenomenon.

 

The heat dome forms when there is a strong change in ocean temperatures, also known as a gradient. This gradient causes warm air, heated by the ocean surface, to rise and move towards land. The northern shifts of the jet stream, which are relatively narrow bands of strong wind in the upper levels of the atmosphere, trap this hot air and move it towards land, where it sinks and causes heat waves.

 

Heat waves are periods of abnormally high temperatures, lasting for more than two days and typically occur between March and June. They can occur with or without high humidity and have the potential to cover a large area, exposing many people to hazardous heat. The impact on humans is measured by the wet-bulb temperature (WBT), which is a limit that considers heat and humidity beyond which humans cannot tolerate high temperatures. Temperatures beyond WBT can cause heat-related illnesses such as heat stroke, heat exhaustion, sunburn and heat rashes.

 

The effects of heat domes are not limited to human health. They can also lead to damage to crops and vegetation, droughts, and an increase in energy demand, particularly electricity. Additionally, heat domes can act as fuel for wildfires, which can destroy a significant amount of land area in the US every year.

 

Climate change is also a concern when it comes to heat domes. According to a 2017 NOAA survey, average US temperatures have increased since the late 19th century. Weather scientists have also highlighted the effects of climate change on more extreme heat waves. However, linking climate change to any specific event can be difficult due to the possibility of other causes or natural variability.

 

In conclusion, heat domes are a dangerous phenomenon that can have severe impacts on human health and the environment. It's important to be aware of the warning signs of heat waves and to take necessary precautions to stay safe during a heat dome. It is different from heat wave as heat dome is a weather pattern that causes heat wave. It is formed by the strong change in ocean temperatures, which causes the warm air to rise and move towards land, where it is trapped by the jet stream and sinks, resulting in heat waves. Image: USA Today