What is an Atmospheric River? Definition, Causes, and How to Track Them

What is an Atmospheric River?

An atmospheric river is a long, narrow band of condensed water vapor that can end up producing heavy rain and snow.

When an atmospheric river moves inland and hits mountains, the water vapor rises and cools, producing heavy precipitation. Meteorologists look at two key factors when an atmospheric river is coming together: where the storm is going to stall once it hits land and a meteorological term known as orographic lifting. Orographic lifting refers to air being forced upward on windward side of mountains which can lead to intense atmospheric river events that result in extensive river flooding.

 

 

What are the Causes of Atmospheric Rivers?

1. Warm Tropical Air Masses

Warm tropical air masses cause atmospheric rivers by creating divergent surface air flow, which results in increased water vapor transport. Atmospheric rivers consist of narrow bands of enhanced water vapor transport, typically along the boundaries between large areas of diverging surface air flow. These bands are caused by the difference in temperature and humidity between tropical regions and more temperate regions. The warm moisture from the tropics is transported towards cooler areas where it condenses into clouds or precipitation, resulting in heavy rainfall or snowfall.

2. Cold Air Masses

Cold air masses cause atmospheric rivers by creating a high concentration of moisture in the air. Prevailing winds blow these ARs across land, where they cool and condense, leading to heavy snow or downpours depending on the elevation.

3. Orographic Conditions

Atmospheric rivers are long, narrow bands of condensed water vapor that can end up producing heavy rain and snow. When an atmospheric river moves inland and hits mountains, the water vapor rises and cools, producing heavy precipitation.

Orographic conditions contribute to the formation of atmospheric rivers because they enhance rainfall as the rain heads towards the mountains. The mountains squeeze out quite a bit more rainfall on one side while reducing it on the other side. This phenomenon can cause damaging floods or quench dangerous wildfires depending on whether it is dry or wet conditions.

4. Precipitation Amounts

Atmospheric rivers are long, narrow corridors of concentrated moisture that travel from the tropics to the western coast of North America. They are associated with heavy rainfall and snowfall, especially along the West Coast. Forecasters predict that the Bay Area will see 1 to 6 inches of additional rainfall from Thursday to Saturday, with the highest numbers along the coast and over mountains. For the West Coast, just a few atmospheric river storms can deliver roughly 30 to 50% of the region’s annual precipitation according to NOAA.

5. Intensity of Atmospheric Rivers

Atmospheric rivers are categorized by a unit of measurement called Integrated Water Vapor Transport (IVT). This takes into account both the amount of water vapor in the system and the wind that moves it around, making it flow like a giant river in the atmosphere. For a storm to be classified as an AR, it must reach an IVT threshold of 250 units. An atmospheric river with IVT of 1,000 or more is considered “extreme”. ARs fall into five categories from weak to exceptional depending on their IVT level. The intensity of atmospheric rivers varies geographically depending on factors such as land use changes and population density which can affect how much moisture is available for storms to absorb.

 

How are Atmospheric Rivers Tracked?

1. Forecasters can use satellite imagery and ground observations to plot atmospheric rivers by measuring the amount of water vapor entrenched in the storm.

2. Atmospheric rivers can be tracked using NOAA’s GOES West weather satellite, which captures images and information about the amount and location of moisture in the atmosphere on the West Coast as often as every 5 minutes.

3. This information is used by weather forecasters to make accurate forecasts of heavy rain and flash flooding, helping people prepare for these events safely.

Consider purchasing the following items to keep you, your family, and your property safe from flooding:

 

What are the Effects of Atmospheric Rivers?

1. They cause high levels of precipitation and flooding.

Atmospheric rivers are storms that occur when warm, moist air from the Pacific Ocean travels across the North American continent and converges with cold air to form long, narrow corridors of concentrated moisture. These corridors can extend for thousands of miles and can carry up to 20 times as much water vapor as normal.

When this moisture-rich air hits land, it causes heavy precipitation which can lead to floods and landslides. Atmospheric rivers have been associated with some of the most destructive floods in recent history, including those caused by Hurricane Harvey in 2017 and Cyclone Gita in 2018.

2. They can cause extreme weather conditions such as tornadoes and hurricanes.

Atmospheric rivers are powerful storm systems that can cause extreme weather conditions such as tornadoes and hurricanes. This is due to their large size and high levels of moisture, which allows them to dump massive amounts of rain over a short period of time.

The impact of atmospheric rivers can be devastating, leading to flooding, mudslides, loss of life and property damage. They have been linked to some of the most costly natural disasters in recent history including Hurricane Harvey in 2017 which caused an estimated $125 billion in damages.

3. They can cause droughts and fires.

The mechanism through which atmospheric rivers can cause droughts and fires is through their impacts on the climate. Greenhouse gases trap heat in the atmosphere, warming the planet and causing more water to evaporate from oceans and lakes. This increased moisture in the air creates stronger storm systems that are longer, wider and wetter.

This increase in intensity can lead to significant economic impacts such as damages from floods or wildfires caused by these storms.

4. They can cause a large amount of snowfall in the Sierra Nevada.

Atmospheric rivers are long, narrow channels of clouds and moisture that stretch across the Pacific Ocean. They can cause a large amount of snowfall in the Sierra Nevada because they bring lots of moisture with them.

This heavy precipitation can park over a region for several days, leading to flooding, mudslides and other disasters. The Bay Area is expected to see up to 6 more inches of rain from Thursday to Saturday with highest numbers along the coast and over mountains.

5. They can affect agriculture and water resources.

Global warming is projected to increase the intensity and duration of atmospheric rivers, leading to increased damages caused by these storm systems.

This could lead to an increase in flooding, erosion and other agricultural damage that may affect water resources. Additionally, changes in the location of atmospheric rivers could impact regions that rely on them for their water supply.

6. They can cause sea-level rise due to melting snow.

The melting of snow due to the increase in atmospheric moisture caused by atmospheric rivers can lead to sea-level rise.

When snow melts, it becomes water and adds to the total volume of water in the ocean. This increases the global sea level and can cause flooding along coastlines. Additionally, as more water is trapped as ice in glacial regions with increasing temperatures, this can lead to an increase in glacial meltwater which also contributes to sea-level rise.

7. They can cause flooding in coastal areas.

Atmospheric rivers are storms that form when warm air travels from the tropics towards the poles, picking up moisture along the way. These storms can be thousands of miles long and can carry more than 100 times as much water as traditional hurricanes.

When atmospheric rivers make landfall, they can cause flooding in coastal areas due to their high precipitation rates and powerful winds that drive storm surges. The force of these storms can also knock down trees and power lines, causing blackouts that leave residents without electricity for days or weeks at a time. Additionally, large amounts of rainwater can seep into ground soil quickly causing landslides in mountainous regions.

 

 

How to Prepare for and Cope with the Effects of Atmospheric Rivers

Step 1: Understand what an atmospheric river is.

An atmospheric river is a long, narrow band of condensed water vapor that can produce heavy rain and snow when it moves inland and hits mountains. Meteorologists look at two key factors when an atmospheric river is coming together: where the storm is going to stall once it hits land, and a meteorological term known as orographic lifting. Orographic lifting refers to the effect mountains have on air currents – when an atmospheric river moves towards mountains, those mountains squeeze out more rainfall than areas on the other side of them.

The effects of an atmospheric river can be devastating for people living in its path. It can lead to flooding due to heavy rainfall that may last for several days or weeks in a row; this can cause damage to homes and property as well as disrupt transportation systems such as roads, airports or railway lines. Additionally, prolonged exposure to high levels of moisture in the air from these storms can increase health risks such as respiratory problems or skin irritation for those who are outdoors frequently during wet weather periods .

Step 2: Make sure you have the tools you need to weather the storm.

To weather the effects of atmospheric rivers, it is important to have the right tools and supplies in your trunk. These include:

• Flashlights with batteries and extra bulbs

• Fire extinguisher and first aid kit

• Shovels, snow blowers and snow tires/chains for your vehicle(s)

• Ice melt or rock salt to keep sidewalks and driveways safe from ice buildup

• Emergency food supplies such as MREs (meals ready to eat) or non-perishable items that do not require cooking or refrigeration.

Step 3: Get out in front of your storm early.

Getting out in front of your storm can help you prepare for and cope with the effects of atmospheric rivers. By understanding the intensity, duration and landfall locations of these storms, you can better prepare yourself for potential impacts such as flooding or power outages. Additionally, by discouraging new construction in high-risk areas and helping people move to safer locations after major disasters, you can reduce the economic damage associated with these storms.

Furthermore, knowing where an atmospheric river may land can help inform decisions about where to build or rebuild infrastructure such as roads or bridges that may be affected by flooding or strong winds associated with these storms. Additionally it is important to keep an eye on changing weather patterns so that you know when it is safe to travel during inclement weather conditions.

Step 4: Prepare for flooding.

1. Monitor atmospheric rivers to plan for potential emergencies and water supply issues.

2. Be aware of the amount and location of moisture in the atmosphere on the West Coast, as it can help forecasters accurately predict heavy rain and flash flooding events.

3. Prepare for these events by making sure you have an emergency kit ready with food, water, first aid supplies and any other necessities you may need in case of an emergency evacuation order or prolonged power outage due to flooding damage.

4. Stay up-to-date with local weather forecasts so that you know when it is safe to venture outside your home or shelter during severe weather conditions like flooding caused by atmospheric rivers storms .

For example: NOAA’s GOES West weather satellite captures images and information about atmospheric rivers as often as every 5 minutes which helps forecasters make accurate predictions about heavy rain and flash flooding events that could lead to loss of life or property damage if not prepared properly beforehand..

Step 5: Know where to go for help.

1. Contact the National Weather Service or local emergency management agency, such as the county fire department or police department. They can provide you with up-to-date information on any potential hazards in your area and guidance on how to prepare for them.

2. Monitor local news outlets for updates on the atmospheric river’s progress and potential impacts it may have on your area.

3. Stock up on supplies such as food, water, batteries, flashlights and blankets in case of an extended power outage caused by flooding or downed trees from high winds associated with the atmospheric river event

You should seek help from local authorities if you are experiencing effects from an atmospheric river event near you – they will be able to provide detailed information about what areas are affected by flooding or other hazards caused by this type of weather phenomenon

Step 6: Take action on climate change.

Action on climate change can help prepare for and cope with the effects of atmospheric rivers. By reducing global greenhouse gas emissions, we can minimize the intensity, duration and landfall locations of these storms. It is also important to discourage new construction in high-risk areas and help people move to safer locations after major disasters. Furthermore, action on climate change can help us better understand atmospheric rivers so that we can better prepare for them in the future.

Step 7: Be prepared for emergencies.

One of the best ways to prepare for and cope with the effects of atmospheric rivers is to be prepared for emergencies. This means having a plan in place in case you need to evacuate your home or business, and being aware of the potential dangers posed by flooding and other weather-related hazards. It also means having a stock of supplies on hand in case you lose power or water, and knowing how to stay safe in the event of severe weather. By being prepared for emergencies, you can help minimize the impact of atmospheric rivers on your life and property.

Step 8: Keep your loved ones informed.

1. Educate yourself on atmospheric rivers and their effects. Learn about the causes, types, and consequences of atmospheric rivers.

2. Share what you have learned with your loved ones in a clear and concise manner so they understand the importance of this phenomenon and its potential impact on their lives.

3. Provide resources for further research if needed or encourage them to take action if they are concerned about the effects of atmospheric rivers in their area or globally.

 

What is the Pineapple Express?

The Pineapple Express is a large band of moisture that extends from Hawaii to the western coast of North America. This atmospheric river often brings heavy rains and strong winds to California, which can lead to flooding and mudslides. The Pineapple Express gets its name from the fact that it often brings warm, moist air to the region from Hawaii, which is sometimes referred to as the “Pineapple State.”

Atmospheric rivers are large bands of moisture that extend over long distances. These rivers can be several thousand kilometers long and a few hundred kilometers wide. They are responsible for most of the moisture that falls along the west coast of North America.

Atmospheric rivers are typically associated with strong winds and heavy rains. They can also bring warm air to a region, which can lead to flooding and mudslides. The Pineapple Express is one example of an atmospheric river that gets its name from the fact that it often brings warm, moist air to the region from Hawaii.