Sea surface temperatures

Meteorologists have been talking for weeks about a snowy season ahead in the southern Rockies and the Sierra Nevada. They anticipate more storms in the U.S. South and Northeast, and warmer, drier conditions across the already dry Pacific Northwest and the upper Midwest. One phrase comes up repeatedly with these projections: a strong El Niño is coming. It sounds ominous. But what does that actually mean? We asked Aaron Levine, an atmospheric scientist at the University of Washington whose research focuses on El Niño. NOAA explains in animations how El Niño forms. What is a strong El Niño? During a normal year, the warmest sea surface temperatures are in the western Pacific and the Indian Ocean, in what’s known as the Indo-Western Pacific warm pool. But every few years, the trade winds that blow from east to west weaken, allowing that warm water to slosh eastward and pile up along the equator. The warm water causes...

The water off South Florida is over 90 degrees Fahrenheit (32 Celsius) in mid-July, and scientists are already seeing signs of coral bleaching off Central and South America. Particularly concerning is how early in the summer we are seeing these high ocean temperatures. If the extreme heat persists, it could have dire consequences for coral reefs. Just like humans, corals can handle some degree of stress, but the longer it lasts, the more harm it can do. Corals can’t move to cooler areas when water temperatures rise to dangerous levels. They are stuck in it. For those that are particularly sensitive to temperature stress, that can be devastating. A transplanted coral in the Port of Miami that was healthy in early 2023 had bleached in the warm water by July 11, 2023. NOAA/University of Miami I lead the Coral Program at the National Oceanic and Atmospheric Administration’s Atlantic Oceanogra...

The Atlantic hurricane season starts on June 1, and forecasters are keeping a close eye on rising ocean temperatures, and not just in the Atlantic. Globally, warm sea surface temperatures that can fuel hurricanes have been off the charts in the spring of 2023, but what really matters for Atlantic hurricanes are the ocean temperatures in two locations: the North Atlantic basin, where hurricanes are born and intensify, and the eastern-central tropical Pacific Ocean, where El Niño forms. This year, the two are in conflict – and likely to exert counteracting influences on the crucial conditions that can make or break an Atlantic hurricane season. The result could be good news for the Caribbean and Atlantic coasts: a near-average hurricane season. But forecasters are warning that that hurricane forecast hinges on El Niño panning out. Ingredients of a hurricane In general, hurricanes are more likely to form and intensify when a tropical low-pressure system encounter...

Hurricane Ian strengthened into a major hurricane on Tuesday as it headed for Florida and was on track to bring dangerous storm surge to the coast and flooding rainfall to large parts of the state. Several areas were under evacuation orders. After a slow start to the 2022 Atlantic hurricane season, Ian formed in ideal conditions, with minimal vertical wind shear, which can tear apart a storm, and warm ocean surface waters providing fuel. Forecasters expect Ian to remain a major hurricane – meaning Category 3 or higher on the Saffir-Simpson Hurricane Wind Scale, with winds over 110 mph – as it heads for landfall in Florida, expected Wednesday. But the scale doesn’t take water risk into account, and flooding and storm surge are both major risks from Ian. Large parts of the state could see 15 inches or more of rain from Hurricane Ian. National Hurricane Center As a meteorologist livin...

There’s an old joke about the fellow who has his left foot in a bucket of ice water and the right in a bucket of hot water, so that his overall temperature is average. That seemed to apply to the climate during 2022’s northern summer of extremes. Global warming is undoubtedly a factor, but just how the increasing extremes – heat waves, droughts and floods, sometimes one on top of the other – are related can be bewildering to the public and policymakers. As a climate scientist, I’ve been working on these issues for more than four decades, and my new book, “The changing flow of energy through the climate system,” details the causes, feedbacks and impacts. Let’s take a closer look at how climate change and natural weather patterns like La Niña influence what we’re seeing around the world today. The June-August 2022 global land and ocean surface temperature was 1.6 degrees Fahrenheit...