Latest news with #LaNiña
Newsweek
2 days ago
- Science
- Newsweek
Map Reveals 'Accelerating' Water Loss Affecting 40 Million Americans
Based on facts, either observed and verified firsthand by the reporter, or reported and verified from knowledgeable sources. Newsweek AI is in beta. Translations may contain inaccuracies—please refer to the original content. The Colorado River Basin has seen an extensive loss of groundwater loss over two decades, with more than half of the loss being in Arizona, according to a new map drawn from NASA satellite data. Analysis by Arizona State University (ASU) researchers has revealed "rapid and accelerating" groundwater loss in the basin's underground aquifers between 2002 and 2024. Some 40 million Americans rely on water from these aquifers, including in parts of Arizona, California, Colorado, Nevada, New Mexico, Utah and Wyoming. The team has warned that "climate change is causing more frequent and intense droughts around the world, including in the Colorado River Basin—which supplies water to seven U.S. states and Mexico—and is facing severe water shortages." The basin lost 27.8 million acre-feet of groundwater over the past two decades, which is roughly equal to the storage capacity of Lake Mead, according to paper author and ASU geoscientist Karem Abdelmohsen. Around 68 percent of the losses occurred in the lower part of the basin, which lies mostly in Arizona. Drag slider compare photos "Lots of attention has gone to low water levels in reservoirs over the years, but the depletion of groundwater far outpaces the surface water losses. This is a big warning flag," said Abdelmohsen in a statement. During the first decade of the study period between 2002 and 2014, parts of the basin in western Arizona (in the La Paz and Mohave counties) and in the southeast of the state (Cochise County) lost groundwater at a rate of around 0.2 inches per year. However, this rate more than doubled, to 0.5 inches per year, in the following decade. Scientists say the acceleration of the groundwater loss is likely down to two factors, including the arrival of a "triple-dip" La Niña between 2020 and 2023. (La Niña is an oceanic phenomenon that sees cooler than normal sea-surface temperatures in the central and eastern tropical Pacific Ocean. La Niña typically leads to reduced rainfall over the Southwest and slows the replenishment of aquifers, NASA explained. A "triple dip" is when we get three consecutive years of La Niña conditions.) A second factor at play may be an increase in the amount of groundwater used for agriculture. Arizona saw a rise in agricultural activity in 2014, when large alfalfa farms arrived in La Paz and other southern parts of the state. Dairies and orchards as well as other popular "thirsty" crops grown in the state, such as cotton, corn, and pecans, likely impacted groundwater supplies, Famiglietti said. According to data from the Arizona Department of Water Resources, 72 percent of the state's available water supply is used for irrigated agriculture. Many farms use "vast" amounts of groundwater, Famiglietti said, partly because they use flood irrigation, where water is released into trenches that run through crop fields. The long-standing practice, commonly used for alfalfa and cotton, tends to be the cheapest option but can lead to more water loss and evaporation than other irrigation techniques, such as overhead sprinklers or dripping water from plastic tubing. The latest study also found evidence that managing groundwater can help keep Arizona aquifers healthier. For example, the active management areas and irrigation non-expansion areas formed as part of the Arizona Groundwater Management Act of 1980 cut down water losses in some areas. The designation of a new active management area in the Willcox Groundwater Basin is also likely to further slow groundwater losses. "Still, the bottom line is that the losses to groundwater were huge," Abdelmohsen said. Do you have a tip on a science story that Newsweek should be covering? Do you have a question about water shortages? Let us know via science@ Reference Abdelmohsen, K., Famiglietti, J.S., Ao, Y. Z., Mohajer, B., Chandanpurkar, H.A., (2025). Declining Freshwater Availability in the Colorado River Basin Threatens Sustainability of Its Critical Groundwater Supplies. Geophysical Research Letters.
Boston Globe
15-07-2025
- Climate
- Boston Globe
Tropical disturbance near Florida to dump extreme flooding rain along Gulf coast
What comes next remains to be seen, as the core of the storm will glide along the shallow waters of the Gulf, likely paralleling the coastline. There is a 40 percent chance that the storm will form a tropical depression and a lesser chance for winds to strengthen to what would be Tropical Storm Dexter. Essentially, a weak pocket of high pressure over the interior southeast may not be strong enough to direct the storm out to the Gulf, which is a good sign in terms of winds. Regardless, sea surface temperatures in the northern Gulf are running in the upper 80s, with the atmosphere already full of moisture. Heavy rain is a lock across the Gulf coast, bringing flooding chances along the Florida panhandle to Louisiana by later in the work week. Advertisement A 40 percent chance for a tropical system to develop exists, mainly over the Gulf. Model tracks show the storm paralleling the Gulf Coast. Boston Globe The highest risk for extensive flooding exists in portions of Louisiana on Thursday and Friday, where the low-lying plain will be doused with 6 to 12 inches of rain in a hurry. This may lead to numerous flooding events, with flooding emergencies possible across New Orleans and Baton Rouge. As of now, it appears this system will stall out over Louisiana and Mississippi, which can create a very dangerous scenario heading into the weekend. Advertisement There is a chance for parts of the Gulf, especially Louisiana, to see double-digit rainfall totals as the tropical system dumps extreme rainfall. Boston Globe Will New England see remnant impacts? In a way, yes. Most of the moisture will push north along the Mississippi River heading into the weekend and will begin to wring out as the western edge of that pocket of high pressure over the Southeast pulls some of the moisture toward the Northeast. The remnant moisture will marginally support a separate system that will lurk near New England this weekend, but it will be minimal and held mostly to the south of our region. How is Atlantic hurricane season shaping up The current season is pacing ahead of schedule. We've had three named storms already, and the third storm is typically named by an average date of Aug. 3. The first named hurricane typically forms by Aug. 11. So we're essentially about three weeks ahead of a typical year, which usually produces 14 named storms, seven hurricanes, of which three usually evolve into a major, Category 3 or higher, hurricane. The National Hurricane Center predicts an above-average season with 13 to 19 named storms, 6 to 10 hurricanes, and between 3 and 5 major hurricanes. Above-average sea surface temperatures, along with the absence of a formidable El Niño or La Niña, are behind the slight increase in forecast tropical activity this season. NOAA predicts an above-average hurricane season for the Atlantic basin. Boston Globe Ken Mahan can be reached at
Yahoo
11-07-2025
- Climate
- Yahoo
Global climate pattern shows signs of shifting. What will happen in the US?
Early signs of a possible La Niña fall and winter are emerging in some climate models, federal forecasters announced July 10. La Niña is a part of a natural climate cycle officially known as El Niño – Southern Oscillation, called ENSO by scientists. The cycle swings between warmer and cooler seawater in a region along the equator in the tropical Pacific. La Niña is marked by cooler-than-average ocean water in the region. It is one of the main drivers of weather in the United States, especially during the late fall, winter and early spring. It's the opposite of the more well-known El Niño, which occurs when Pacific Ocean water is at least 0.9 degree warmer than average for three months. La Niña and El Niño typically have minimal impact on summer weather in the United States, other than some effects on hurricanes. Winter is the one season when they have the most impact. A typical La Niña winter in the United States brings cold and snow to the Northwest and unusually dry conditions to most of the Southern states, according to the Climate Prediction Center. The Southeast and mid-Atlantic also tend to see higher-than-average temperatures during a La Niña winter. Meanwhile, New England and the Upper Midwest, including New York, tend to see lower-than-average temperatures, the Weather Channel said. More: Will a hurricane impact your state in 2025? Odds get an update. The typical impacts of a La Niña winter in North America include a wetter, colder winter in parts of the northern United States and a drier, warmer winter in parts of the southern United States. La Niña is a natural climate pattern marked by cooler-than-average seawater in the central and eastern Pacific Ocean. When the water cools at least 0.9 degree Fahrenheit below average for three straight months, a La Niña is declared. "While this may sound like a small change in temperature, it can cause significant changes in the weather patterns around the globe," AccuWeather meteorologist Brian Lada said. In general, La Niña conditions favor hurricane development in the Atlantic basin, which includes the Caribbean Sea and the Gulf of America, formerly known as the Gulf of Mexico. This is because during La Niña, the strong storm-killing winds known as wind shear relax across the Atlantic basin, allowing hurricanes to more easily develop. Hurricane researcher Phil Klotzbach of Colorado State University, in a July 10 email to USA TODAY, explained that "while Caribbean shear has been quite strong in June and is likely to remain strong throughout most of July, the potential trend more towards cool neutral (or even weak La Niña) later in the season may result in lower shear in the Caribbean later in the season." The lower the wind shear, the greater the chance for hurricane development in the Atlantic basin. But the status of ENSO is only part of the hurricane puzzle: Twenty years ago, in 2005, for instance, ENSO-neutral conditions also occurred in the Pacific ‒ and that year spawned the infamously destructive hurricanes Katrina and Rita, the National Weather Service said in an online report. Right now, it appears to be a toss-up. While so-called "ENSO-neutral" conditions are most likely through the late summer, thereafter, chances of La Niña conditions increase into the fall and winter 2025-26, forecasters from the Climate Prediction Center (CPC) said July 10. In fact, one climate model used by the CPC – the North American Multi-Model Ensemble – "favors the onset of La Niña conditions during the Northern Hemisphere fall," the CPC said in its monthly update. Japan's weather bureau also announced July 10 that there is a 40% chance of La Niña emerging in the fall. Overall, the CPC said the chances for La Niña remain comparable to the likelihood of ENSO-neutral continuing. ENSO-neutral means neither El Niño (warmer waters) nor La Niña (cooler waters) conditions are dominant in the Pacific. While El Niño and La Niña have expected impacts on global seasonal weather and climate, what about neutral? "ENSO-neutral doesn't mean we expect upcoming seasonal rain, snow, and temperature to be close to average," writes Emily Becker in the CPC's ENSO blog. "Rather, during neutral, we don't have the same predictive information that El Niño and La Niña's atmospheric changes provide, making upcoming patterns harder to predict very far in advance." Contributing: Reuters This article originally appeared on USA TODAY: 2025 La Niña forecast says major shift may be brewing
Indian Express
11-07-2025
- Climate
- Indian Express
Temperatures along equatorial Pacific Ocean to remain neutral till October: NOAA
The US agency National Oceanic and Atmospheric Administration (NOAA) said Thursday El Niño-Southern Oscillation (ENSO) neutral conditions would prevail along the equatorial Pacific Ocean until October this year, meaning the Indian summer monsoon would not be under the threat of either El Niño or La Niña till the end of this season. Part of the ENSO climatic cycle, El Nino is known to negatively interfere with the monsoon and in the past, subdued rainfall was linked to the conditions. 'ENSO neutral conditions are likely over the Northern hemisphere during August-October. Later, La Niña conditions increase during the winter of 2025-2026,' NOAA said in its latest monthly ENSO bulletin. The sea surface temperatures recorded along the equatorial Pacific Ocean in June ranged between 0 and 0.4 degree Celsius. The coupled ocean-atmospheric system in the tropical Pacific Ocean reflected ENSO neutral conditions. Earlier this month, the India Meteorological Department (IMD) had also said that the latest Monsoon Mission Climate Forecast System (MMCFS) and other climate models suggest that these neutral conditions will likely persist till the end of the monsoon season. On the ENSO component close to home, known as the Indian Ocean Dipole, the Met department had said, 'Currently, neutral Indian Ocean Dipole (IOD) conditions are being observed over the Indian Ocean. The model forecast indicates a possible transition to negative IOD conditions during the coming months'. ENSO, an ocean-atmospheric phenomenon considered as one of the most important recurring natural events capable of altering the global atmospheric circulation, has three phases: warm (El Nino), neutral, and cool (La Nina). La Niña is known to positively influence the southwest monsoon and bring normal or above-seasonal rainfall, and El Niño has been linked with below-average seasonal rainfall and even droughts in some years.
Yahoo
10-07-2025
- Climate
- Yahoo
Global climate troublemaker La Niña may arrive later in 2025
Early signs of a possible La Niña fall and winter are emerging in some climate models, federal forecasters announced July 10. La Niña is a part of a natural climate cycle officially known as El Niño – Southern Oscillation, called ENSO by scientists. The cycle swings between warmer and cooler seawater in a region along the equator in the tropical Pacific. La Niña is marked by cooler-than-average ocean water in the region. It is one of the main drivers of weather in the United States, especially during the late fall, winter and early spring. It's the opposite to the more well-known El Niño, which occurs when Pacific Ocean water is at least 0.9 degree warmer than average for three months. La Niña and El Niño typically have minimal impact on summer weather in the U.S., other than some effects on hurricanes. Winter is the one season when they have the most impact. A typical La Niña winter in the U.S. brings cold and snow to the Northwest and unusually dry conditions to most of the Southern states, according to the Climate Prediction Center. The Southeast and mid-Atlantic also tend to see higher-than-average temperatures during a La Niña winter. Meanwhile, New England and the Upper Midwest into New York tend to see lower-than-average temperatures, the Weather Channel said. More: Will a hurricane impact your state in 2025? Odds get an update. The typical impacts of a La Niña winter in North America include a wetter, colder winter in parts of the northern United States and a drier, warmer winter in parts of the southern United States. La Niña is a natural climate pattern marked by cooler-than-average seawater in the central and eastern Pacific Ocean. When the water cools at least 0.9 degree Fahrenheit below average for three straight months, a La Niña is declared. "While this may sound like a small change in temperature, it can cause significant changes in the weather patterns around the globe," AccuWeather meteorologist Brian Lada said. In general, La Niña conditions favor hurricane development in the Atlantic basin, which includes the Caribbean Sea and the Gulf of America. This is because during La Niña, the strong storm-killing winds known as wind shear relax across the Atlantic basin, allowing hurricanes to more easily develop. Hurricane researcher Phil Klotzbach of Colorado State University, in a July 10 e-mail to USA TODAY, explained that "while Caribbean shear has been quite strong in June and is likely to remain strong throughout most of July, the potential trend more towards cool neutral (or even weak La Niña) later in the season may result in lower shear in the Caribbean later in the season." The lower the wind shear, the greater the chance for hurricane development in the Atlantic basin, as this map shows: But the status of ENSO is only part of the hurricane puzzle: Twenty years ago, in 2005, for instance, ENSO-neutral conditions also occurred in the Pacific ‒ and that year spawned the infamously destructive hurricanes Katrina and Rita, the National Weather Service said in an online report. Right now, it appears to be a toss-up. While so-called "ENSO-neutral" conditions are most likely through the late summer 2025, thereafter, chances of La Niña conditions increase into the fall and winter 2025-26, forecasters from the Climate Prediction Center (CPC) said July 10. In fact, one climate model used by the CPC – the North American Multi-Model Ensemble – "favors the onset of La Niña conditions during the Northern Hemisphere fall," the CPC said in its monthly update. Japan's weather bureau also announced July 10 that there is a 40% chance of La Niña emerging in the fall. Overall, the CPC said the chances for La Niña remain comparable to the likelihood of ENSO-neutral continuing. ENSO-neutral means neither El Niño (warmer waters) nor La Niña (cooler waters) conditions are dominant in the Pacific. While El Niño and La Niña have expected impacts on global seasonal weather and climate, what about neutral? "ENSO-neutral doesn't mean we expect upcoming seasonal rain, snow, and temperature to be close to average," writes Emily Becker in the CPCs' ENSO blog. "Rather, during neutral, we don't have the same predictive information that El Niño and La Niña's atmospheric changes provide, making upcoming patterns harder to predict very far in advance." Contributing: Reuters This article originally appeared on USA TODAY: Global climate troublemaker La Niña may be brewing
