What is an Atmospheric River

Understanding the natural phenomena around us in the world can help us better predict and prepare for various weather conditions. One such phenomenon, which plays a significant part in our global climate and weather patterns, is the Atmospheric River. In this article, we will delve into this fascinating topic, breaking down its complexities for you. What is an Atmospheric River?

Atmospheric Rivers are relatively long, narrow regions in the atmosphere like “rivers in the sky” that transport H2O vapor outside of the tropics & can vary in size and strength, with the average carrying an amount of H2O vapor equivalent to the average flow of H2O to 15x’s of the Mississippi River.

Atmospheric Rivers can contain the largest amounts of water vapor and can create extreme rainfall and floods, often by stalling over watersheds vulnerable to flooding. These events can disrupt travel, induce mudslides, and cause catastrophic damage that lie in their path. A well-known example is the “Pineapple Express,” a strong atmospheric river that is capable of bringing moisture from the tropics near Hawaii over to the U.S. West Coast.



What is an Atmospheric River


An Atmospheric River is a plume of moisture that helps carry saturated air from the tropics to higher latitudes. Essentially, they are long regions in the atmosphere that transport water over significant distances, similar to how a river on Earth transports water. An Atmospheric River can be hundreds to thousands of kilometers long and can bring a substantial amount of atmospheric water from the tropics to drier regions, especially in the eastern part of the US.

Atmospheric River over Los Angeles.
Atmospheric river over Los Angeles.

They normally carry precipitation events from the tropics to other parts of the world. These Atmospheric Rivers can carry as much as 15 times the amount of water in the Mississippi River. Most Atmospheric Rivers can bring enough precipitation to areas that welcome it but others can lead to billions of dollars of damage. As the earth warms, Atmospheric Rivers have the potential to hold more water that could cause flooding, especially in places like California which could cause larger swings between drought and flood. 

The concept of an atmospheric river can be quite fascinating. Imagine, a river flowing above our heads in the earth’s atmosphere, carrying enormous amounts of moisture. This atmospheric river is very crucial as it contributes significantly to the distribution of water on Earth. In fact, these atmospheric rivers have a pivotal role in the earth’s water cycle and are responsible for about 90% of the north-south transport of water in the atmosphere.

However, just like a typical river, an atmospheric river also has its challenges. While they are essential for supplying fresh water, an atmospheric river can also cause floods when it delivers excessive amounts of precipitation to coastal regions. Despite these potential adverse effects, it’s amazing to think about these invisible rivers flowing in our earth’s atmosphere.

Studying atmospheric rivers is an important aspect of meteorology as they impact weather patterns and climate. Moreover, understanding these atmospheric rivers can potentially enhance our ability to forecast heavy rainfall events and develop better flood prevention strategies. To wrap up, an atmospheric river is a significant component of our earth’s system, impacting both atmospheric and weather phenomena on Earth.


Understanding the Phenomenon of Atmospheric Rivers


Atmospheric Rivers are a fascinating weather phenomenon that has garnered significant attention from the Global Atmospheric Administration due to their potentially devastating impacts. To understand these high-intensity atmospheric events, we must first look at what they are and how they form.

Essentially, Atmospheric Rivers are long, narrow regions in the atmosphere akin to “rivers in the sky” that transport water vapor from the tropics toward the poles. The presence of atmospheric rivers is a key factor in the distribution of precipitation rain and snow to many regions worldwide.

Atmospheric rivers can range in size, but typically extend thousands of kilometers in length and can be hundreds of kilometers wide. They play a crucial role in the global water cycle and are critical to our understanding of precipitation patterns and events.

Despite their name, it’s important to note that rivers atmospheric in nature don’t hold water in the same way rivers on Earth do. Instead, they carry water vapor, which can turn to rainfall when it encounters the right conditions over land.

The intensity of atmospheric rivers is also significant. It’s not uncommon for one atmospheric river event to carry twice the volume of the Amazon River in water vapor. But, as we’ve seen from atmospheric river-driven weather events, they also carry with them the potential for extreme weather. In fact, the NOAA’s atmospheric administration attributes about 30-50% of the annual precipitation on the West Coast to atmospheric rivers. So, while they can be beneficial, bringing much-needed rainfall to certain areas, they can also cause severe flooding and other weather-related disasters.

The impacts of atmospheric rivers on our weather patterns can’t be understated. If we are to successfully predict and prepare for the extreme weather events they can cause, we must continue to study and understand these complex atmospheric river systems.  NOAA is dedicated to providing up-to-date information on these and other vital environmental topics. Especially into the world of atmospheric rivers and the pivotal role they play in our global climate.


Impact of Atmospheric Rivers


Atmospheric Rivers, particularly strong atmospheric ones, have a significant impact on the weather patterns we experience. These rivers can bring about severe weather conditions; from an ordinary storm that causes light rain to heavy thunderstorms that could potentially result in flooding. For example, on many occasions, California has witnessed the power of atmospheric rivers firsthand because of the dramatic shifts between draught and flooding that Atmospheric Rivers create.



These rivers can carry an immense amount of water comparable in scale to massive terrestrial rivers. Imagine the profound influence such an entity could have on weather patterns! As they flow through the atmosphere, they distribute moisture once hitting landfall and, more importantly, have a significant hand in producing large amounts of rain. But, not just any rain we’re talking about substantial, heavy rainfall that can drastically change the weather over a region in a short amount of time.

In fact, atmospheric rivers are often linked to violent weather events worldwide. From the stormy coasts of California to other continents, they bring about heavy rain that’s often associated with rapid weather changes. When these atmospheric rivers are particularly strong, they may result in a storm that precipitates not just rain but heavy rain, making the situation potentially dangerous.

With these atmospheric rivers, an ordinary day could swiftly turn into a day of incessant rain, courtesy of the weather whims of these rivers.  Even in sunny California, the weather can shift dramatically when such a river decides to unload its content. Here, it’s not unusual for a storm to turn into a sequence of storms, all thanks to the atmospheric rivers.

The impact of atmospheric rivers on the weather is clear. Whether it’s causing a storm, creating heavy rainfall, or even spawning a series of storms, their influence is undeniable. However, this does not always have to spell disaster. If predicted and prepared for, the resultant rain, even if heavy at times, can be beneficial, especially for regions like California that are no strangers to droughts.

Atmospheric River Research: Contributions and Advances


Renowned organizations like NOAA (National Oceanic and Atmospheric Administration), through persistent dedication to science and research, have been able to shed more light on atmospheric rivers. Future studies are anticipated to provide even more insight, allowing us to better predict and manage these events. The wealth of data obtained is crucial in expanding our understanding of these occurrences. With better understanding, we can better anticipate, prepare for, and mitigate the risks associated with these events, especially during winter when snow is prevalent.

Recent events, as reported in the news in January, centered around atmospheric rivers have significantly contributed to the growing accumulation of information regarding this atmospheric phenomenon. With easy access to the internet and readily available images, more people are becoming informed about atmospheric rivers. Having an NOAA account can ease the process of accessing ad-free information straight from the government (gov) website.

When you log onto the gov site, a treasure trove of data becomes available for you to peruse at your convenience. The West, especially areas like San Francisco, commonly experiences the impact of Atmospheric Rivers. By staying up to date with the data provided by organizations such as NOAA, communities in their path can better understand atmospheric events and how these events may impact your home, your community, and the world at large.

Evolving science can give better predictions and is the cornerstone of improving societal resilience against the potentially harmful effects of Atmospheric Rivers. As the world continues to grapple with climate change, continuous research and understanding of atmospheric rivers may provide a ray of hope and a path forward in our collective journey toward a more sustainable future.




Atmospheric Rivers are relatively long, narrow regions in the atmosphere like “rivers in the sky” that transport H2O vapor outside of the tropics & can vary in size and strength, with the average carrying an amount of H2O vapor equivalent to the average flow of H2O to 15x’s of the Mississippi River and as little as a much-needed shower in dry areas of the Country.

Atmospheric rivers play a crucial role in Earth’s water cycle, contributing to both floods and drought alleviation. Helping to understand these phenomena better MyWaterEarth&Sky; has continuously provided accurate and significant information.

Enhancing our knowledge will allow us to predict and mitigate potential natural disasters and utilize the opportunities these atmospheric rivers present. Despite their intimidating name, atmospheric rivers are an essential part of our natural world. By continuing our research and expanding our understanding, we can benefit from their existence and lessen their potential threats.


JimGalloway Author/Editor



NOAA- What are atmospheric rivers?

Live Science-What is an Atmospheric River



Q: What is an Atmospheric River?
A: An atmospheric river is a long region in the atmosphere that transports water over significant distances, similar to how a river on Earth transports water. It can carry saturated air from the tropics to higher latitudes and be hundreds to thousands of kilometers long.
Q: What role does an Atmospheric River play in our climate and weather patterns?
A: Atmospheric Rivers significantly contribute to our global climate and weather patterns. They play a pivotal role in the earth’s water cycle and are responsible for about 90% of the north-south transport of water in the atmosphere. Furthermore, they can drastically influence local weather patterns by causing substantial rainfall, sometimes leading to floods.
Q: What are the challenges associated with Atmospheric Rivers?
A: While atmospheric rivers are essential for supplying freshwater, they can cause floods when they deliver excessive amounts of precipitation to coastal regions. This can lead to potential adverse effects, particularly when these rivers are particularly strong.


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