Latest news with #MJO
Boston Globe
4 days ago
- Climate
- Boston Globe
How are the early weeks of hurricane season shaping up?
There's a fast ramp up in late summer and a fast cool down in early fall. Notice in the chart below how quickly the prevalence of hurricane and tropical storms becomes by mid-August but how fast it falls off later in September. The average Atlantic hurricane season in terms of storms per date. NOAA Advertisement Specifically, they show the number of hurricanes (yellow area) and combined named storms and hurricanes (red area) that occur on each calendar day over 100 years. The data has been smoothed using a 5-day running average centered on each calendar day. For the Atlantic basin, the chart is based on data from the 77 years from 1944 to 2020 (starting at the beginning of the aircraft reconnaissance era) but normalized to 100 years. The peak of the Atlantic hurricane season is Sept. 10, with most activity occurring between mid-August and mid-October. Related : Advertisement There's already been some activity in the Pacific, which again is typical. Pacific hurricane season begins May 15, a full two weeks earlier than the Atlantic because water temperatures are more conducive earlier in the Eastern Pacific. The Pacific season is also more drawn out, with tropical activity remaining high from July through much of September. A similar chart to what I showed you for the Atlantic has a much more plateaued look in the Pacific. Typical Eastern Pacific tropical storm and hurricane activity for an average tropical season. NOAA Back in the Atlantic, various influences will ignite more activity or suppress it. If the trade winds are weak, there's not a lot of dry air, and water temperatures are above average, tropical storm formation can accelerate. If we have cooler-than-average temperatures off of Africa — think of it like a cousin to La Niña and call it the Atlantic La Niña — then that cooler-than-average water will limit tropical activity. Likewise, dry Sahara dust coming off the African continent will suppress thunderstorm development over the ocean, which you need to get tropical storms and hurricanes. A blob of cooler-than-average water off the coast of Africa this June is likely contributing to suppressed tropical activity. NOAA Other influences on hurricane season include the Maiden-Julian Oscillation. This is a band of rotating tropical activity that occurs in the tropical Pacific Ocean. Depending on what part of its cycle the conveyor belt of thunderstorms associated with the MJO is located, it will enhance or suppress tropical energy. If an area of rising air forms over the Atlantic, then more thunderstorms will occur, perhaps leading to an organized tropical system. Last year the first named storm, Alberto, brought heavy rain and flooding to Mexico and parts of Texas. The storm was named on June 17, well within the average. Advertisement Early season storms tend to form in the Western Caribbean, the Gulf of Mexico, or off the US southeast coast. The water is this region warms up faster than in the open Atlantic, where development is typically later in the summer and fall. Typically during June, tropical storms and hurricanes emerge close to the mainland United States. Boston Globe This year, the National Weather Service has predicted there's a 90 percent chance of a near- or above-normal hurricane season. There's only a 10 percent chance that we will see fewer tropical systems than usual. Once we do have a named storm, it will be called Andrea followed by Barry and Chantel. If some of these names seem familiar, it's because they are rotated on a five-year basis. Unless a storm causes significant death and destruction, the name will be reused —otherwise it can be retired. In 2024, the World Meteorological Organization retired Beryl, Helene, and Milton from the Atlantic basin list and retired John from the Eastern Pacific list due to their destructive impacts. Lastly, remember that we have not seen a hurricane reach New England shores since Bob in 1991, and we are statistically way overdue. It's not a bad idea to at least think about what you would do if a hurricane were to strike and make some preparations just in case.
News18
12-06-2025
- Climate
- News18
Monsoon Arrived 8 Days Early In Kerala, Why Has It Progressed So Slow Since Then?
Last Updated: By early June, the monsoon's pace slackened. Rainfall eased in most southern and northeastern parts of the country. Even flood-affected areas in the Northeast began to dry up. The southwest monsoon, a lifeline for agriculture and water needs, arrived with a bang but has since entered a puzzling pause. When it reached Kerala on May 24, eight days ahead of schedule, it sparked widespread celebration across the country. The India Meteorological Department (IMD) called it the earliest onset since 2009. Hopes soared as rain lashed southern parts of the country. But now, deep into the second week of June, the monsoon's momentum has mysteriously stalled, leaving much of the country grappling with heat and uncertainty. The monsoon's early entry wasn't just confined to Kerala. It simultaneously swept into Lakshadweep, Mahe, southern Karnataka, parts of Tamil Nadu, and Mizoram, an unusually widespread onset that delighted meteorologists and farmers alike. The last week of May saw intense rainfall in Kerala, with red alerts issued in multiple districts due to flooding and landslides. But by early June, the monsoon's pace slackened. Rainfall eased in most southern and northeastern parts of the country. Even flood-affected areas in the Northeast began to dry up. According to private forecaster Skymet, the monsoon's advancement has hit a temporary wall, particularly in northeastern states. Meteorologists attribute the sluggish progress to a mix of global atmospheric and oceanic shifts. The early burst was helped by favourable conditions like the active phase of the Madden-Julian Oscillation (MJO), a moving pulse of cloud and rainfall over the tropics, and a neutral Indian Ocean Dipole (IOD). The absence of El Nino, a phenomenon that typically suppresses monsoon rains, also worked in the country's favour. But June brought a shift. The MJO lost steam, weakening the systems that propel the monsoon northward. In addition, the seasonal low-pressure area that usually drives the monsoon's inland advance remains south of its expected position, restricting rain to southern coastal regions. Despite the slowdown, the IMD has issued a new round of forecasts that may bring hope. Between June 11 and 17, heavy to very heavy rainfall is expected to return to Kerala and Lakshadweep. Wind speeds may reach 60 km/h, and isolated areas could see extreme rain from June 14 to 17. However, the monsoon remains sluggish over Maharashtra, Goa, and much of the Northeast. The early-season flooding in Kerala is giving way to heat and humidity, a pattern mirrored in several parts of the country. Will Monsoon Regain Momentum? The IMD remains optimistic about the broader monsoon season. It has projected overall rainfall at 105% of the long-period average, an encouraging sign for agriculture and the economy. Yet, weather experts caution that early onset does not guarantee a successful or well-distributed monsoon. In 2009, the monsoon had also arrived early, on May 23, but June that year saw a severe 48% rainfall deficit, and August followed with a 27% shortfall. The memory of that anomaly is prompting meteorologists to urge caution amid early excitement. First Published: June 12, 2025, 14:25 IST
Washington Post
11-06-2025
- Climate
- Washington Post
Hurricane season is off to a fast start — at least in the Pacific Ocean
A flurry of tropical cyclone activity over the past two weeks in the eastern Pacific Ocean just off the west coast of Mexico has produced three named storms so far — with more storms expected. Early Wednesday, a system named Cosme was a weak tropical storm about 500 miles from the southern tip of the Baja California peninsula. Earlier in the workweek, Barbara became the first hurricane of the season in the northern hemisphere when it maxed out at a 75 mph Category 1. The storms follow Alvin, which formed in late May. All have been swirling out at sea, none threatening land thus far. This spurt of activity shows no signs of ending for now. Additional disturbances are already on the map, and the same general pattern is expected to persist through the month. It's a whole other story in the Atlantic Ocean, where it has been calm and no storms have yet developed. The National Hurricane Center is monitoring two additional areas in the eastern Pacific Ocean. The first, currently south of the Gulf of Tehuantepec, has a 90 percent chance of storms in the next week. It is slated to take a similar path to recent systems, tracing the coast of Mexico several hundred miles offshore. Weather model forecasts suggest a coherent low pressure system will slowly develop and could become a named system in a region similar to the earlier three. On its heels, there are signs that yet another disturbance will form near the coast of Central America late weekend or into early next week. It is also expected to end up in an environment favorable for a tropical cyclone, but since it's more distant, the forecast is less certain. Any concerns of storms hitting landfall are minimal for now. Instead, the storms are expected to bring moisture to Mexico and the southern U.S. Storms in the Pacific have mostly formed where expected this time of year; they have just been more frequent than typical. The three named storms to date are more common at the end of June or early July. Similarly, the first hurricane in the Pacific doesn't typically arrive until the last week of June. A somewhat favorable phase of the tropical Madden Julian Oscillation may have helped recent storms along. The MJO is characterized by eastward propagating weather patterns that either promote rising air and storminess or sinking air and stability. This pass of the MJO was expected to trickle into portions of the Atlantic ahead but may stall out before getting much past the Central American continent. While the burst of storms has been notable, it's far from unheard of. As recently as 2021, there were three named storms by June and six by the end of the month. Closing in on two weeks into the Atlantic hurricane season that began June 1, there has yet to be anything serious brewing in the basin. That may continue for a while as there are minimal signs of development in the near future. While it's not unusual for the Pacific Ocean to kick off first — its season begins May 15 — many recent years have featured early named storms in the Atlantic Ocean. This year is unusual. Over the past decade all seasons but one had a named storm in the Atlantic by this date. The exception was 2024, when the first named storm in what would become a very active and destructive season waited until June 19 to capture a name. Water temperatures remain warmer than average in most of the Atlantic despite comparative cooling versus this time last year. Frequent episodes of dust associated with the Saharan Air Layer and unfavorably strong winds across development regions may be helping stifle activity, although most storms this early in the season form closer to home in the Gulf of Mexico or near the Southeast coast. The fact that cold fronts have tended to get hung up over the Southern U.S. rather than further offshore may play a role as those zones tend to offer development in May and June. The global hotspot for tropical development is expected to remain in the eastern Pacific through the rest of June, according to the Climate Prediction Center. Released Tuesday, their outlooks for the weeks of June 18 to June 24 and June 25 to July 1 indicate a high likelihood of additional tropical development in the region. As far as the Atlantic goes, the center also includes the Bay of Campeche in the potential development region mid-month but tends to favor quieter conditions. Even so, disturbed areas of weather can become tropical cyclones on short notice — and it's important to remain vigilant as the summer progresses.
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.
Indian Express
30-05-2025
- Science
- Indian Express
Daily subject-wise quiz : Environment and Geography MCQs on Perito Moreno glacier, Madden-Julian Oscillation and more (Week 112)
UPSC Essentials brings to you its initiative of subject-wise quizzes. These quizzes are designed to help you revise some of the most important topics from the static part of the syllabus. Attempt today's subject quiz on Environment and Geography to check your progress. 🚨 Click Here to read the UPSC Essentials magazine for May 2025. Share your views and suggestions in the comment box or at With reference to the Madden-Julian Oscillation (MJO), consider the following statements: 1. It is a moving system of winds, clouds, and pressure that brings rain as it circles around the equator. 2. This system typically travels westward at a speed of 4-8 metres per second. 3. When MJO is in the active phase, it results in drought. How many of the statements given above are correct? (a) Only one (b) Only two (c) All three (d) None Explanation — The southwest monsoon arrived in Kerala on May 24, eight days earlier than usual, although it reached Mumbai two weeks earlier on May 26. This was also the earliest monsoon to arrive in Mumbai on record. — Several large-scale atmospheric-oceanic and local causes contributed to the early monsoon onset, but the Madden-Julian Oscillation (MJO) was a crucial driver, according to the India Meteorological Department (IMD). — The MJO is a moving system of winds, clouds, and pressure that produces rain as it circles the equator. The phenomena is named after Roland Madden and Paul Julian, two scientists who discovered it in 1971 while working at the National Centre for Atmospheric Research in Boulder, Colorado. Hence, statement 1 is correct. — The system normally moves eastward at a speed of 4-8 metres per second. It travels across the world in 30-60 days on average, but can sometimes take 90 days. Hence, statement 2 is not correct. — As it moves, intense MJO activity frequently divides the world into two parts: one in which the MJO is active and produces rainfall, and another in which it suppresses rainfall. MJO causes higher-than-normal rainfall during the active phase, whereas in the suppressed phase, the area receives less than average rainfall. Hence, statement 3 is not correct. Therefore, option (a) is the correct answer. The Perito Moreno glacier was in the news. It is part of: (a) Alps Mountains (b) Himalayas Mountains (c) Andes Mountains (d) Atlas Mountains Explanation — Argentina's most famous glacier, the Perito Moreno glacier, which has a surface area of 250 sq km (lies in the Andes Mountains), is crumbling. It lost a colossal block of ice, equivalent to a 20-story building, plunging 70 m into water below. — Argentina's most famous glacier, the Perito Moreno glacier, which has a surface area of 250 sq km (the total area of Patna, Bihar), is crumbling. Just weeks ago, it lost a colossal block of ice, equivalent to a 20-story building, plunging 70 m into water below. Therefore, option (c) is the correct answer. With reference to the bow echo, consider the following statements: 1. It is a line of storms, also called a squall line. 2. It is used to classify Tsunamis. Which of the statements given above is/are correct? (a) 1 only (b) 2 only (c) Both 1 and 2 (d) Neither 1 nor 2 Explanation — The severe storm that pounded Delhi on Sunday had a unique structure, according to weather radar imagery from the India Meteorological Department (IMD). The storm resembled a crescent or an archer's bow. In technical terminology, such storm presentations are referred to as 'bow echoes'. — A bow echo is a line of storms, also known as a squall line, on radar that resembles a bow. This storm line may occasionally be embedded in a bigger squall line. Hence, statement 1 is correct. — A bow echo can range from 20 to 100 kilometres and last three to six hours. — Ted Fujita, a Japanese-American meteorologist who developed the tornadoes classification system, coined the word in the 1970s. Hence, statement 2 is not correct. Therefore, option (a) is the correct answer. Consider the following statements: Statement 1: Western Disturbances also impact the weather outside the winter season. Statement 2: In the last 70 years, Western Disturbances have become more common in May, June, and July, months where they were previously rare. Which one of the following is correct in respect of the above statements? (a) Both Statement 1 and Statement 2 are correct and Statement 2 is the correct explanation for Statement 1. (b) Both Statement 1 and Statement 2 are correct and Statement 2 is not the correct explanation for Statement 1. (c) Statement 1 is correct but Statement 2 is incorrect. (d) Statement 1 is incorrect but Statement 2 is correct. Explanation — Western Disturbances are rain-bearing wind systems that begin east of Afghanistan and Iran and pick up moisture from the Mediterranean, Black, Caspian, and Arabian Seas. — These are examples of extratropical cyclones caused by low-pressure zones created by the interplay of polar and tropical winds. Western Disturbances are embedded in the subtropical westerly jet stream, which is a high-altitude, fast-moving air movement that runs from west to east in the Earth's atmosphere and passes over the Himalayan and Tibetan highlands. — They are most abundant during the boreal winter months (December to March) and have an impact on the weather in India, notably the northwest, Pakistan, Afghanistan, and Tajikistan. — Western Disturbances are also now impacting the weather outside the winter season. In the last 70 years, they have become more common in May, June, and July, months where they were previously rare, according to the 2024 study. One reason for this trend could be the 'delayed northward retreat of the subtropical jet, which historically has occurred before the onset of the summer monsoon.' Hence, statements 1 and 2 are correct. Both Statement 1 and Statement 2 are correct and Statement 2 is the correct explanation for Statement 1. Therefore, option (a) is the correct answer. Karreguttalu Hill (KGH) region — a known stronghold of Naxalite groups was in the news. It is located in: (a) Telangana-Chhattisgarh region (b) Chhattisgarh-Madhya Pradesh region (c) Maharashtra-Karnataka region (d) Karnataka-Telangana region Explanation — The Centre stated that incidences of violence by Left Wing Extremism (LWE) have decreased to 374 in 2024 from its maximum number of 1936 in 2010. — While LWE-related violence has decreased by 81 per cent, 'the total number of deaths, including civilians and security forces, has also reduced by 85 per cent — from 1005 deaths in 2010 to 150 in 2024,' according to a government news statement. — The news release continued: 'Recently, in one of the biggest anti-Naxal operations in the country's history, security forces achieved a major breakthrough in the fight against LWE along the Chhattisgarh-Telangana border.' — It stated that a huge operation was carried out between April 21 and May 11, 2025, in the Karreguttalu Hill (KGH) region, which is a renowned stronghold of Naxalite organisations. Therefore, option (a) is the correct answer. Sorry for the inconvenience caused. All remaining questions and answers are correctly marked. Daily Subject-wise quiz — History, Culture, and Social Issues (Week 112) Daily subject-wise quiz — Polity and Governance (Week 112) Daily subject-wise quiz — Science and Technology (Week 112) Daily subject-wise quiz — Economy (Week 112) Daily subject-wise quiz — Environment and Geography (Week 111) Daily subject-wise quiz – International Relations (Week 111) Subscribe to our UPSC newsletter and stay updated with the news cues from the past week. Stay updated with the latest UPSC articles by joining our Telegram channel – IndianExpress UPSC Hub, and follow us on Instagram and X.
