For dog owners, one of the absolute best feelings is walking in the door after a long day and seeing your pup waiting for you, tail wagging full speed and ready to give you all their love. The message in this case is obvious: “I’m so happy you’re here!!!” 

However, a wagging tail can have a few different meanings, including “I’m not so sure about you yet…” Dogs don’t have the vocabulary to tell us how they feel, so they’ve developed other ways to get the point across, and their tail is one of the most expressive tools they’ve got.

Because a wagging tail can express a variety of different emotions and messages, reading it correctly means paying attention to more than just the motion.

Wagging 101

A wag is built from a few different variables, and each one carries information. The two most important things to look for are position and speed. A tail held at a loose, neutral height — roughly level with the body — paired with a wide, sweeping motion is the classic happy-to-see-you wag. 

The faster the wag, the more excited the pup. Think about when a dog does the “helicopter wag,” where the tail is basically doing a full circle — that’s a very, very happy pooch.

A tail tucked low or between the legs signals fear or submission, especially if paired with a slow wag. A tail that’s held high and stiff, often arched over the animal’s back, can signal aggression or wariness. An alert (more stiff than relaxed) tail wagging at about body-height often indicates curiosity and uneasiness. 

Another way to look at it is that tail position indicates mood, while wagging speed indicates intensity. The faster a wag, the more intense the emotion, be it happiness, fear, or aggression.

Left or Right?

There’s one more detail to pay attention to: direction. In a 2007 study published in Current Biology, researchers found that dogs tend to wag more to their right when they feel something positive, such as seeing their owner, and more to the left when they feel negative or uncertain. 

Not only that, but other dogs can pick up on these feelings, growing more anxious when they see a fellow pooch wagging to the left — even if they’re just seeing a video of another dog. In another study, some dogs would even approach the screen when dogs in a video wagged to the right, suggesting a friendly nature. 

However, the researchers noted that this left/right communication may simply be a result of different emotions activating different hemispheres of the brain. It’s not as if dogs got together one night to play poker and decide what “left” would signal and what “right” would, like some secret code.

But because a wag can mean so many things, it’s a mistake to treat one as a guaranteed invitation. As experts note, the tail should be read alongside the rest of the body — the ears, the posture, whether the dog is loose or tense. A wag tells you only that a dog is feeling something, and often that something is joy. But not always.

So, if a dog is baring its teeth and snarling at you with pure rage in its eyes, the only tail you should be worrying about is hightailing it out of there.

If you’ve been paying attention to weather forecasts lately, you may have heard that not only are we experiencing El Nino this year, but that it’s also one of the strongest on record. Because the climate pattern develops every few years, you’ve likely heard the name before and know it has something to do with the weather.

But what exactly is El Nino, and why should we take a “super El Nino” so seriously? 

Depending on where you live, the latter question may be especially important, because El Nino can create very dangerous conditions across much of the globe, including flooding and drought.

Not only that, but the weather event can last for several months, if not longer. That makes this a good time to understand how El Nino forms and why it reshapes weather around the world.

El Nino Gives Warm Weather a Push

El Nino is the warm phase of a natural climate cycle called the El Nino-Southern Oscillation, or ENSO. The cycle has three phases: El Nino, La Nina, and a neutral period in between. Together, they reflect an ongoing conversation between the central/eastern tropical Pacific Ocean and the atmosphere above it.

To understand El Nino, it helps to start with what happens during a typical year. Strong trade winds blow steadily from east to west across the equatorial Pacific, pushing warm surface water toward Asia and Australia. 

As that warm water piles up in the western Pacific, cold, nutrient-rich water rises to the surface off the coast of South America in a process called upwelling. This cold water supports some of the world’s richest fisheries, and it’s a good thing for the whole marine food web.

During an El Nino, however, those trade winds weaken — sometimes they even reverse. Without the winds pushing it, warm surface water begins to spread back eastward across the Pacific toward the Americas. The usual upwelling of cold water is suppressed, allowing sea surface temperatures in the central and eastern Pacific to climb well above average.

It’s Everyone’s Problem

That shift may seem local, but it changes where heat and moisture are released into the atmosphere. Because warm ocean water heats the air above it, the main zone of rising air and thunderstorms moves as well. One of the biggest consequences is a shift in the jet stream, the fast-moving river of air high in the sky that helps steer storms across North America. 

During many El Nino winters, the Pacific jet stream strengthens and shifts farther south. This often brings wetter-than-average conditions to the southern United States, including California and the Gulf Coast, while parts of the northern U.S. and Canada tend to experience milder and drier winters. 

The powerful 1997-98 El Nino, for example, helped create what some journalists called “the year without a winter.” The shift can also fuel more thunderstorms and lightning in parts of North America, and some studies have found that El Nino years are associated with increased tornado activity as well.

But El Nino’s influence extends far beyond North America. Peru and parts of South America often experience heavy rains and flooding. Eastern Africa may become wetter than normal. Meanwhile, Australia, Indonesia, and parts of Southeast Asia are more likely to face drought, increasing the risk of wildfires and crop failures.

How El Nino Got Its Name

Ocean ecosystems also feel the effects: The 2015–16 El Nino contributed to a global coral bleaching crisis that devastated large sections of Australia’s Great Barrier Reef, for example. And the loss of nutrient-rich cold water off the coast of Peru reduces its fish population, something noticed by fishermen even centuries ago.

In fact, these fishermen along the Pacific coast of Peru noticed that warmer water and the resulting threat to their livelihood seemed to occur every few years, peaking in late December. Because the warming coincided with the celebration of Jesus’ birth, they called the phenomenon El Nino de Navidad, which translates to “the Christmas Child.”

So What Is La Nina?

La Nina (Spanish for “the little girl”), meanwhile, represents the opposite phase of the cycle. In a La Nina year, trade winds become stronger than usual. Cold water thus wells up more vigorously in the eastern Pacific, and many of El Nino’s typical weather patterns are reversed. The Pacific Northwest often becomes cooler and wetter, the southern U.S. tends to be drier, and Atlantic hurricane seasons are generally more active.

Scientists still don’t fully understand what causes the ENSO cycle to flip between its different phases, though it emerges from complex feedback cycles between ocean temperatures, winds, and atmospheric pressure across the tropical Pacific. El Nino events typically develop every two to seven years, usually beginning in spring or early summer, peaking during the winter months, and lasting roughly nine to 18 months.

Although El Nino strongly influences weather, it doesn’t dictate it. Other climate patterns, day-to-day weather variability, and long-term climate change all continue to shape what ultimately happens in any particular place. Meteorologists often say El Nino “tilts the odds” rather than guaranteeing specific outcomes. 

But, with the 2026-27 El Nino coming in hot (literally) as one of the strongest to date, the odds are tilted more than usual.

Each year, tens of thousands of tourists flock to remote parts of the far north for a very specific reason. It’s not to visit Santa’s Workshop — it’s to see the northern lights. 

These colorful bands of undulating light are called auroras and are named after ancient Roman gods: Aurora is the goddess of the dawn. Aurora borealis, the lights seen in the Northern Hemisphere, are named after the god of the northern wind. Aurora australis, aka the southern lights, are named after the god of the southern wind.

The majestic names appropriately describe the cosmic light show, which seems like something out of a fantasy movie. But the northern lights (and the southern lights) are purely natural, bound by the laws of physics. The colorful phenomenon originates on the surface of the sun, nearly a hundred million miles away. 

In space, the sun creates what’s known as solar storms. And the northern lights? You can think of them as a solar storm’s lightning.

The Colors of the (Solar) Wind

The sun is an enormous thermonuclear reactor, ceaselessly emitting radiation in all directions. These particles traveling through space are called solar wind, and are part of the universe’s cosmic weather. If you thought Florida was bad, imagine a solar storm. Solar storms occur when more particles explode from the sun than usual, through solar activity such as flares and coronal mass ejections.

Just as strong wind here on Earth can create thunderstorms, strong solar wind becomes solar storms. The energy produced by solar storms is massive — a nuclear reactor would need to operate continuously for hundreds of thousands of years to approximate the electromagnetic radiation produced by a single solar flare. 

Sometimes, Earth orbits directly into the path of this radiation. This would spell doom for us earthlings, were it not for an invisible force field protecting the planet. That force field is known as the magnetosphere — which has nothing to do with Magneto from X-Men, and everything to do with Earth’s magnetic field. 

When it’s not helping birds migrate, the magnetic field protects our planet by guiding harmful solar radiation around Earth. Like water going around a rock in a stream, solar wind flows around the planet.

But particularly strong “gusts” of solar wind accelerate particles fast enough to penetrate the magnetosphere and enter Earth’s upper atmosphere.  Electrons from the sun collide with oxygen and nitrogen in the air, causing each atom to emit a flash of light. Some atoms become electrically charged, or ionized, in the process as well, which also creates light.

Different gases emit different colors, depending on the altitude. Oxygen interacting with solar wind at an altitude of 120 miles or more produces red, while at lower altitudes it produces green — the most common aurora color. Nitrogen, on the other hand, produces blue and pink. 

Replicate the process billions of times and you’ve got quite the (northern) light show! The colors form tall curtain-like bands because they’re actually shaped by normally-invisible lines in Earth’s magnetic field.

Unfortunately, most of us don’t see auroras in the wild because they tend to only occur in the northernmost and southernmost reaches of the globe. This is because Earth’s magnetic field funnels solar particles to the poles, just as it guides migrating birds north and south. However, when a solar storm is strong enough, the magnetic field is overwhelmed and particles can reach the atmosphere at lower latitudes.

Often, the stronger the storm, the further south the northern lights can appear. They’ll also be more colorful as particles reach lower altitudes than usual. In 2026, the largest solar storm in two decades created aurora that could even be seen over Southern California — at that point, calling them northern lights is borderline confusing!

Solar storms that powerful are rare, though, and auroras are typically confined to the Arctic and Antarctic. If you don’t have plans to spend a night under Arctic skies anytime soon, don’t sweat — er, freeze — it, though. Just head to Vegas, because neon lights are made using the same process that generates the northern lights in our atmosphere. The science is just more… down to earth.