What is a Heat Dome? The science behind dangerous, long-lasting heat waves

Heat Dome Explained: It’s Like a lid on a bubbling pot

The basic phenomenon that creates the prolonged and intense heat waves often called “heat domes” is this: large amounts of air are heated high in the atmosphere over an area of the earth and this air mass get trapped or parked there, not able to move to cooler regions for days or weeks.

It is very warm to scorching on the ground below it because the system is basically parked on top and doesn’t let any heat dissipate in the higher atmosphere above us — it keeps it there. “A heat dome is when a region of the United States is locked in a system of the highest pressure you could imagine for about a week, essentially trapping heat and moisture within,” meteorologist Mike Smith explained in 2021 while explaining a heat dome that the West experienced.

For some scientific terminology: The American Meteorological Society define a “heat dome” in its “AMS glossary” as: “A regional phenomenon when an exceptional heat episode that affects over half a state, which occurs during June-August, can cause heat impacts across 25% of the U.S. Population in summer.

This refers to an air mass trapped underneath high-pressure system; the circulation of air brings about stagnant conditions in which the atmosphere is heated from below. The sinking air caused by the ridge, due to high atmospheric pressure aloft, compress and heat up, with solar radiation exacerbating this heating process on the ground, trapping the hot air under an insulating ridge that acts like a dome.” The 2021 weather system that we talked about that parked itself over Pacific Northwest was particularly egregious and had a scientific impact not quite previously observed with similar patterns of this nature.

What causes a heat dome?

What happens when a heat dome causes molecules to mosh pit on the surface of Earth like an awful, stifling concert…

A heat dome forms over an area when a high pressure area-essentially a ridge of high pressure-builds and stalls in place over a certain region for days or weeks. The pattern causes air in the atmosphere to descend, compresses that air and as air descends, those tiny air molecules bump against one another and become warmer — like what occurs at a mosh pit — thus intensifying the heat. High pressure also keeps cloud cover away, allowing for maximum exposure to sunlight.

The intensity of solar radiation beating down on the Earth’s surface will only contribute to heat that rises back into the air again where the same cycle of warming occurs.

The drying effects the heat will have on the land also means any available moisture will either evaporate at an extremely rapid rate, or plants and soil will have nowhere to get rid of the heat, as they can only become warmer as a result, contributing to the risks of drought and wildfire risk that are associated with extreme and protracted heat. The pattern of jet stream wind flow over Earth plays a very crucial role in steering these high pressure patterns.

When these high altitude winds stagnate, break, or take a weaker and more meandering path across the globe, the jet stream will be unable to ‘push’ away from an area the hot air associated with the heat dome and will instead allow it to become stalled or lodged over the same location for an extended period of time.

What is the difference between heat dome and heat wave?

Although the term “heat wave” is now colloquially the product of the phenomenon known as a “heat dome,” technically the term means simply that a temperature is several degrees higher than normally for a period of about three consecutive days or more.

Henceforth, we use the standard scientific use of the term to refer to a heat wave. A heat wave, on the other hand, will be the consequence of the underlying mechanism we call a “heat dome”. That will always result in a record high heat dome; thus, we don’t say a ‘heat dome event that causes a record heat wave’ or any similar thing.

How deadly are they? The effects and health impact of heat domes

High atmospheric pressure may contain some of the hottest weather phenomena known to man on our globe; we will call it what’s commonly done to heat waves that occur via extreme pressures as a ‘heat dome’ but here’s the bottom line: This trapped heat and humidity can be overwhelming and even deadly.

“When that heat and humidity can no longer escape the surface layer, it can also result in warm overnight temperatures that don’t offer respite,” explained climate science writer Jason Neff, “This will cause people to exert themselves, straining their cardiovascular and renal systems in addition to exhausting their energy. This will affect particularly children and the elderly, whose bodies are less able to respond.”

It can lead to record-setting temperatures on day and night, as the trapped air just continues to become warmer, the body’s ability to sweat will be severely limited, making it difficult for people to cool themselves, the combination of rising temperatures will cause widespread dehydration and increase risk of all sorts of chronic health problems as well as severe cases like heat exhaustion or heatstroke.

The August heatwave that plagued the USA: New Orleans at 102 degreesF set a record dating back to 1980, the heat wave the last time that it happened in June was recorded back to 1855.

While the Summer 2021 “heat dome” was believed by the U.S. Government to have contributed to the premature deaths of several hundred people in the Pacific Northwest region of the United States, including the state of Washington, where 371 deaths have been recorded. These deaths attributed to the “heat dome” all took place between July 3 and 7. Another death attributed to the heat dome took place in June from a heat wave caused by an extreme heat dome.

Are Heat domes related to Climate Change?

“Scientists are increasingly confident that the human-caused increase in the Earth’s average temperature, driven by global warming, is intensifying these heat domes and extending them even longer,” warned climate change specialist David L. Williams and climate reporter Maria E. Johnson, who explained that “Climate change is increasing global average air temperatures.

And this means that when high-pressure systems come into play that create heat domes, those domes will likely be higher, and they can sustain higher temperatures longer,” said climate scientist, David W.

Keith, of Columbia University. They also state: “heat waves themselves are more common than they once were. In the U.S., the average frequency of a heat wave, defined as a heat wave lasting three or more consecutive days of temperatures at or above the historical normal maximum, rose from just over one event per year in the 1960s to more than six a year in the 2010s.” Studies of past weather extremes can also help scientists to estimate the contribution of climate change.

According to a study on the 2021 Pacific Northwest heatwave of, in a 2021 study co-authored by climate scientists at Stony Brook University and Princeton University, it was found that due to anthropogenic global warming, a heat dome over Pacific Northwest would have been “at least 150 times more probable compared to preindustrial times.”

However, even with increased atmospheric temperatures as a result of rising human contributions to air pollution “the impact on our jet streams may make it so that we continue to see such events even with lower atmospheric temperatures as a factor in heat domes; for instance higher western Pacific ocean temperatures may well influence the path of your local jet stream such that hot air more often stagnates over the land than move east, helping to bring about more frequent heat domes,” as was described in a New York Times article.

Safety Tips During Heat Dome event

Stay Cool

stay indoors and in air conditioned locations, as well as, on occasion visiting official cooled shelters which you may wish to be accompanied with to a cooling center where public officials may bring you, or get you water, or both!

Be hydrated

It may seem simple to want you’re body to cool down. That is an impossible if you dehydrate yourself!

Don’t abandon young or elderly ones, (Or those of health conditions)

It may be the greatest service that anyone could do for you to provide to you the information on how to get them there from here!

Never EVER abandon young people and those with health conditions…

Take note as to the above list for advice as the United States National Ocean and Atmospheric Administration as stated that “heat stress to a person is caused by the sun and increased ambient temperature, which affects every element of a person’s physiology.

There are two forms of heat illness, which can be severe or fatal. They include heat exhaustion which comes before a heat stroke”.

When the heat index can reach over 90 degrees F, a heat dome has to be considered as possible if there’s an oppressive and extensive pattern of very hot weather.

People should not leave any living things – be it children, adults or pets – unattended while inside vehicles due to the high temperatures that can cook living beings in a matter of minutes.