What is El Niño and how does it affect the US?
El Niño is one of the phases of the El Niño-Southern Oscillation (ENSO), a natural cycle of variability in the ocean and atmosphere that affects the tropics and beyond. The opposite phase of El Niño is La Niña, when the sea surface temperatures in the same region are cooler than average. El Niño and La Niña typically last for several months to a year or more, and have a range of impacts on temperature, precipitation, and storm activity in different regions of the world.
According to the National Oceanic and Atmospheric Administration (NOAA), there is a greater than 55 percent chance of at least a strong El Niño from January through March 2024, and a 35 percent chance that this event will be historically strong for the November to January season. This means that the sea surface temperatures in the key monitoring region, known as the Niño-3.4 region, are expected to be 1.5 degrees Celsius or warmer than the long-term average, and possibly reach or exceed 2 degrees Celsius.
El Niño tends to bring warmer and drier conditions to the northern tier of the US, especially the Pacific Northwest and the northern Rockies, while the southern tier of the US, especially the Southwest and the Southeast, tends to experience cooler and wetter conditions. El Niño also alters the jet stream, the fast-moving river of air that steers storms across the continent. A stronger El Niño usually means a stronger and more active southern jet stream, which can bring more storms and precipitation to the southern states, and sometimes along the East Coast.
What are the impacts of El Niño on winter weather?
The impacts of El Niño on winter weather vary depending on the location, the strength of the event, and other factors, such as climate change and natural variability. However, some general trends can be observed based on past El Niño events and the current outlooks from NOAA and other sources.
- Snow and ice: El Niño tends to reduce the chances of snow and ice in the northern states, where the temperatures are likely to be above average and the storms are less frequent. However, El Niño can also increase the chances of snow and ice in the southern states, where the temperatures are likely to be below average and the storms are more frequent. Some parts of Southwest and Southside Virginia may get whitened and/or glazed on Saturday as wet weather pattern continues. El Niño can also enhance the chances of major snowstorms along the East Coast, especially in the Mid-Atlantic region, where the cold air from the north can interact with the moist air from the south.
- Flooding and landslides: El Niño tends to increase the risk of flooding and landslides in the southern states, where the precipitation is likely to be above average and the storms are more intense. This is especially true for California, where El Niño can bring heavy rain and mountain snow, causing flash floods, mudslides, and debris flows. El Niño can also trigger atmospheric rivers, narrow bands of moisture that transport large amounts of water vapor from the tropics to the West Coast, resulting in extreme rainfall and snowfall events.
- Drought relief and fire danger: El Niño tends to bring some relief to the drought-stricken areas of the Southwest and the Southeast, where the precipitation is likely to be above average and the soil moisture is likely to improve. However, El Niño may not be enough to end the long-term drought that has been affecting parts of the West and the South for years, as the accumulated deficits are too large to be erased by one season of wet weather. El Niño can also reduce the fire danger in the southern states, where the moisture is likely to increase and the vegetation is likely to green up. However, El Niño can also increase the fire danger in the northern states, where the dryness is likely to persist and the vegetation is likely to dry out.
How to prepare for El Niño winter weather?
El Niño winter weather can pose various challenges and hazards for people living in different parts of the US, depending on the local conditions and impacts. Therefore, it is important to stay informed and prepared for the potential weather events that may affect your area. Here are some tips to help you get ready for El Niño winter weather:
- Check the forecast: Monitor the weather forecasts from reliable sources, such as NOAA, the National Weather Service, and your local media, and pay attention to any watches, warnings, or advisories that may be issued for your area. You can also sign up for emergency alerts from your local authorities or use mobile apps that can notify you of severe weather events.
- Prepare your home: Make sure your home is well-insulated and weatherproofed, and that your heating system is working properly. Clean your gutters and drains, and repair any leaks or cracks that may cause water damage. Trim any trees or branches that may fall on your roof or power lines. Have a backup generator or alternative heating source in case of power outages. Stock up on food, water, medicine, and other essentials that can last for at least three days.
- Prepare your car: Make sure your car is well-maintained and equipped with winter tires, chains, antifreeze, windshield wiper fluid, and a full tank of gas. Have a winter emergency kit in your car, including blankets, flashlights, batteries, jumper cables, flares, first aid kit, and snacks. Avoid driving in hazardous conditions, such as snow, ice, rain, or fog, and follow the road signs and directions from the authorities. If you get stuck or stranded, stay in your car and call for help.
- Prepare yourself: Dress appropriately for the weather, wearing layers of warm and waterproof clothing, gloves, hats, scarves, and boots. Avoid exposure to extreme cold or heat, and watch out for signs of hypothermia or heat exhaustion. Stay hydrated and eat well-balanced meals. Avoid unnecessary travel or outdoor activities, and stay indoors as much as possible. Check on your family, friends, neighbors, and pets, and help those who may need assistance.
