Latest news with #ElNiñoSouthernOscillation
The Hindu
19 hours ago
- Science
- The Hindu
Why is the El Niño so hard to predict?
A: The El Niño Southern Oscillation (ENSO) is a climate phenomenon with three phases: warm, cool, and neutral. Depending on the phase in a year, ENSO affects the climate in the world's tropical and subtropical regions, including the monsoons, so scientists track it closely. But climate models have historically struggled to model the ENSO, leading to uncertainties in weather prediction worldwide. Some reasons include the following. The conditions required for a clear ENSO signal only emerge in early summer, so forecasts before then quickly lose value. Short-lived westerly wind bursts can 'kick' the ENSO towards warm or cool phases and inject chaos into weather systems. Warm-water or wind anomalies in the Indian Ocean and other basins can reinforce or dampen ENSO. Scientists also disagree on which basin matters most when representing these links in models. Recently, scientists with the CLIVAR Pacific Region Panel Working Group reported a potential advance. They reported a model called a recharge oscillator (RO) that treats ENSO as a contest between just two variables: sea-surface temperature in the central-eastern Pacific and the amount of warm water stored below the surface further west. They reported in Reviews of Geophysics that RO was able to reproduce all of ENSO's features, including its cycles, habit of peaking in December, and the difference in the sizes of its phases.
Yahoo
11-06-2025
- Climate
- Yahoo
Colorado State University updates its 2025 hurricane season forecast
A balm of stifling Saharan dust and tepid water temperatures in the deep Atlantic have subdued early tropical development this hurricane season, but that's no reason to relax. Colorado State University's forecast for above average activity this season remains unchanged in its regular June update. The report, issued June 11, maintains the university's prediction first made in April for 17 named storms and nine hurricanes. Of the nine hurricanes, four are forecast to become major hurricanes of category 3 or higher. An average season has 14 named storms, seven hurricanes, including three major hurricanes. While it's not unusual for June to remain quiet — the average first named storm doesn't appear until June 20 — some tropical meteorologists have described the early days of the 2025 Atlantic hurricane season that began June 1 as 'sluggish' and 'docile.' Just one area has so far been highlighted by the National Hurricane Center for potential development on June 2 and it never got above a 10% chance before fizzling two days later. Phil Klotzbach, a hurricane researcher with CSU and the lead author of the forecast, said early season activity, or lack thereof, doesn't foreshadow what will happen later in the season. 'Compared to the last few years maybe it's sluggish because the odds of having a Category 5 in the Caribbean are pretty low,' Klotzbach said. More: 2025 hurricane season could see degraded forecasts because of weather service cuts Last year, Beryl formed on June 30. It quickly strengthened to a Category 5 hurricane on July 2 in the southeastern Caribbean, making it the earliest Cat 5 on record in the Atlantic basin. CSU's prediction is partly based on the unlikelihood that a storm-thwarting El Niño will form, and above average sea surface temperatures in the Caribbean Sea and the subtropical eastern Atlantic Ocean. Unlike previous years, the water temperatures in portions of the main development region between Africa and the Caribbean are mostly normal or even slightly cooler than normal. Temperatures in the Gulf of Mexico, renamed by the U.S. government as Gulf of America, continue to be near record warm. Warm water provides fuel for tropical cyclones to form and intensify. Klotzbach called the signals used to make this year's seasonal forecast in some areas of the tropics 'murky' and said there's likely to be a clearer picture of what's in store in CSU's update next month, which is scheduled for release July 9. 'There's still a lot of time for the tropics to lock in on what they are going to be,' Klotzbach said. 'It's kind of a mixed bag. Not every season is busy or quiet, some are dead on average.' Mother Nature is not making this season easy to predict, with the atmosphere expected to be in a neutral phase of the El Niño Southern Oscillation, or ENSO. An El Niño pattern typically points to a less active season. A La Niña pattern can mean a more active season. Neutral can lean either way, but averages two to three more named storms than a normal season. More: Hurricane hunters save lives, but NOAA plane breakdowns, staffing shortages put them at risk AccuWeather also left its seasonal forecast unchanged in a recent update, although lead hurricane forecaster Alex DaSilva said he believes a named storm in June is possible in the northwest Caribbean or Bay of Campeche. AccuWeather forecast between 13 and 18 named storms, seven to ten hurricanes, and three to five major hurricanes. DaSilva said cooler water temperatures in the main runway between Africa and the Caribbean could mean fewer of the ferocious Cabo Verde hurricanes that form close to Africa and stalk across Atlantic. The National Hurricane Center forecasts for the myriad tropical waves in that area because they can be the seedlings of tropical cyclones, but of the estimated 60 waves that tumble off the coast each hurricane season only a fraction become hurricanes. DaSilva is more fearful of storms rapidly intensifying, especially near a coastline where people may not have as much time to get out of harm's way. 'The Gulf is on fire, and that's a concern,' DaSilva said. 'You might see a tropical storm near the islands and all of a sudden it's a major hurricane on someone's doorstep.' Kimberly Miller is a journalist for The Palm Beach Post, part of the USA Today Network of Florida. She covers real estate, weather, and the environment. Subscribe to The Dirt for a weekly real estate roundup. If you have news tips, please send them to kmiller@ Help support our local journalism, subscribe today. This article originally appeared on Palm Beach Post: Hurricane season 2025 updated forecast released by Colorado State
Indian Express
01-06-2025
- Climate
- Indian Express
Mumbai city wettest district this season so far, logs 3,025% of actual avg rainfall
With record-shattering downpour sweeping the region in May, Mumbai city district has logged excess rainfall of over 3025 per cent of its actual average rainfall for the season, making it Maharashtra's wettest district until May. Meanwhile, the Santacruz station has recorded an excess rainfall by 1945 per cent. Overall, Maharashtra recorded 'large excess' rainfall by 560 per cent until May. In what made for an unusual summer, heatwaves and above normal temperatures eluded the city in May as it started receiving unseasonal showers, followed by pre-monsoon rain, as early as May 6. After intermittent spells of moderate showers, Mumbai experienced its earliest onset of southwest monsoon in the past 75 years as torrential rainfall battered the city on May 26. Spurred by unseasonal showers and early onset of monsoon, records from the India Meteorological Department (IMD) show that Mumbai city district has recorded 'large excess' in showers by 3,025 percent while the suburban district has recorded above normal rainfall by over 1,945 percent. According to the data, the IMD's Colaba station in island city received 503.2 mm rainfall in May, as against its average of 16.1 mm rain from March to May. Meanwhile, the Santacruz observatory in Mumbai suburbs received 378.4 mm rainfall, marking a significant departure from its actual average of 18.5 mm rain for the period. For the record, this has been the wettest May month ever recorded in Colaba since 1918 while also being Santacruz' rainiest May in the past 25 years. Not just Mumbai, but the entire Maharashtra has recorded an excess of 560 per cent from its actual long-period average (LPA) until May 31. While the state typically receives an average of 26 mm rain during the months of March to May, it has recorded an average of 170.3 mm rainfall until May 31. Besides Konkan region, district-wise rain data from the IMD show that Madhya Maharashtra region has recorded an excess in showers by 457 per cent so far, while Vidarbha belt has registered excess downpour of over 481 per cent. Meanwhile, the region of Marathwada has recorded an excess of 394 per cent so far. Meteorologists have attributed the heavy showers to a combination of favourable factors ranging from an upper-level trough that ushered in heavy rain early in May to a low pressure area which developed into a well-marked LPA in the Arabian Sea after May 20. Furthermore, senior IMD scientists have also pointed to active Madden-Julian Oscillation (MJO) as well as the neutral El Niño Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD) conditions as factors contributing to an early onset. After rainy May, the IMD has said that the city, as well as other parts of the country, will continue to receive 'above normal' rainfall in June. The above normal rain will also usher in a dip in temperatures which are likely to remain in the normal to below normal range across the region. Typically, Mumbai receives an average of 537 millimetres of rainfall in June, during which it experiences monsoon onset. On Sunday, the city and its neighbouring districts woke up to brief spells of moderate showers amid a nowcast warning sounded by the IMD at 10 am, followed by another warning at 1 pm. According to the IMD, the city will continue to experience light to moderate rainfall in the coming days with the showers slated to intensify and be accompanied by thunderstorms, from June 5. While no alerts have been issued for Mumbai, a fresh yellow alert stating the likelihood of 'thunderstorms with moderate rain and gusty winds' has been sounded in Thane for June 5.
Yahoo
29-05-2025
- Climate
- Yahoo
2025 Atlantic hurricane season is expected to be busy: How that could impact Tennessee
NASHVILLE, Tenn. (WKRN) — The National Oceanic and Atmospheric Administration (NOAA) is predicting an active Atlantic hurricane season in 2025, and like in 2024, we could see impacts here in Tennessee. The Atlantic hurricane season goes from June 1st to November 30th. During the typical season, there are 14 named storms, with seven of those strengthening to a hurricane, and three of them becoming major hurricanes. Want the forecast delivered directly to your inbox? Sign up for the News 2 Forecast Newsletter The forecast from NOAA is for 13-19 named storms, 6-10 of those hurricanes, and 3-5 major hurricanes. Remember, a storm gets named when it reaches a minimum tropical storm strength. That means it has sustained winds of 39 to 73 mph. Hurricanes have winds over 74 mph, and major hurricanes have winds over 111 mph. Hurricanes are rated on the Saffir-Simpson scale. This means the wind speed of the storm determines the category. The scale goes from category 1 to 5. NOAA says there are a couple of factors that caused them to forecast an active season. They said the neutral El Niño Southern Oscillation (ENSO) can lead to an increase in storms in the Atlantic. ENSO is the ocean current in the southern Pacific Ocean, and it can impact the Atlantic Hurricane season as well as our weather during the winter. RADAR | Track weather across TN live The other reason they are forecasting an active hurricane season is that the sea surface temperatures in the Gulf and the Atlantic are warmer than normal. Warm sea surface temperatures are what help fuel hurricanes. Above normal activity has been common over the last several years. Eight out of the last 10 years have seen 15 or more named storms, and in 2020, we saw the most active Atlantic hurricane season on record, with 30 storms! In the 2024 Atlantic hurricane season, there were 18 named storms, 11 of which were hurricanes, and 5 strengthened to major hurricanes. Last hurricane season, we saw impacts from 3 hurricanes here in Tennessee. The biggest impacts came from Hurricane Helene, with the historic/devastating flooding in East Tennessee. Hurricane Francine brought heavy rain and a low tornado threat to middle Tennessee. Hurricane Beryl caused tornadoes in Arkansas and heavy rain in West Tennessee. It's rare to see impacts from three hurricanes in Tennessee, but with the active forecast, we could see tropical impacts this year. ⏩ The main threats from hurricanes here in Tennessee are flooding and tornadoes. By the time hurricanes reach the Volunteer State, they are typically weakened to just tropical depression strength. This means damaging winds aren't a threat like they are when they first make landfall. During the months of August, September, and October, tornadoes are extremely rare in Tennessee, but if we see the remnants of a hurricane, we can get tornadoes. They are typically weak, short-lived tornadoes of EF-0 or EF-1 strength. Here is a list of the names for the 2025 Atlantic hurricane season. Don't forget to take the power and reliability of the WKRN Weather Authority with you at all times by downloading the News 2 Storm Tracker app. Copyright 2025 Nexstar Media, Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.
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Business Standard
27-05-2025
- Business
- Business Standard
IMD raises monsoon rain outlook to 106% of the long-period average
The India Meteorological Department (IMD) on Tuesday raised its monsoon forecast for 2025, projecting rainfall at 106 per cent of the long-period average (LPA), up from 105 per cent predicted in April. It also expects June rainfall to be 'above normal', at over 108 per cent of the LPA. Cumulative monsoon rainfall between 105 per cent and 110 per cent of the LPA during the June-September period is considered 'above normal'. The seasonal LPA for the country, calculated over the period from 1971 to 2020, stands at 87 centimetres. The forecast for seasonal June-September rainfall carries a margin of error of +/- 4 per cent. The agency said rainfall across nearly all of India's homogenous regions — except the Northeast and parts of Bihar — was likely to be normal to above normal this year. Arunachal Pradesh, Assam and Meghalaya could see below-normal rains, according to IMD's regional outlook. 'Above-normal' June rainfall is expected to keep maximum temperatures across most of India at or below seasonal averages, with no heat waves anticipated. The month typically receives 165.4 millimetres of rainfall. Monsoon rainfall in the 'core zone' — which comprises key rain-fed agricultural regions — is also forecast to be above normal, with a 56 per cent probability of strong precipitation. Good monsoon rain across key rainfed regions in central and western India could significantly boost pulses and oilseed output, potentially reducing the country's dependence on high-cost imports. Overall, a strong and well-distributed southwest monsoon is expected to bolster kharif crop production and leave behind significant residual soil moisture for a healthy rabi harvest. Agriculture was projected to account for about 16.35 per cent of India's gross domestic product (GDP) in FY25, according to the government's second advance estimate. A robust harvest could help the government curb food inflation and provide more room for the Reserve Bank of India to cut benchmark interest rates in FY26. It may also encourage the government to be more liberal on farm exports. The central bank has forecast 6.5 per cent GDP growth and 4 per cent retail inflation for FY26. Food inflation, as measured by the consumer price index, dropped to 1.78 per cent in April, from 2.69 per cent in March. Oils & fats and fruit were the only categories with double-digit inflation in April. 'Currently, neutral El Niño Southern Oscillation (ENSO) conditions are prevailing over the equatorial Pacific regions, while the latest Monsoon Mission Climate Forecast System, as well as other model forecasts, indicates that the neutral ENSO conditions are likely to continue during the monsoon season. The Indian Ocean Dipole (IOD), which is another factor that could influence Indian monsoon, is also expected to be weakly negative,' said IMD Director General Mrutyunjay Mohapatra. He expressed confidence in the agency's 'above normal' forecast, citing improved accuracy in recent years. He said that between 2021 and 2024, IMD's average absolute error of the operational forecast was 2.28 per cent of the LPA for the second-stage forecast, and 3.15 per cent of the LPA for the first-stage forecast. 'This was well within the error range of +/- 4 per cent,' Mohapatra said. While the average absolute error of the forecast for the previous four years (2017 to 2020) of both first and second-stage forecasts was 7.5 per cent of the LPA. The southwest monsoon reached Kerala on May 24 this year, marking its earliest arrival over the Indian mainland since 2009, when it reached the southern state on May 23. The primary rain-bearing system set in over Mumbai 16 days before the usual date, making it the earliest since 1950. The southwest monsoon usually makes its onset over Kerala by June 1, reaches Mumbai by June 11, and covers the entire country by July 8. It starts retreating from northwest India around September 17 and withdraws completely by October 15. Meteorologists caution that the date of monsoon onset has no direct correlation with overall seasonal rainfall. Early or late arrival in Kerala or Mumbai doesn't necessarily determine the rain's progress or distribution elsewhere in the country, which is determined by large-scale variabilities and global, regional and local features. India saw 934.8 millimetres of rainfall in 2024 — 108 per cent of the average. In 2023, it had recorded 820 millimetres, 94.4 per cent of the average. It had seen 925 millimetres of rainfall in 2022; 870 millimetres in 2021; and 958 millimetres in 2020, according to the IMD data. (With agency inputs)
