Latest news with #MJO
Indian Express
2 days ago
- 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
4 days ago
- 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.
Indian Express
7 days ago
- Climate
- Indian Express
IMD Mumbai Director interview: ‘Timeline of the monsoon doesn't matter. We can expect many days of heavy to very heavy rain'
From no heat wave day to heavy pre-monsoon showers that shattered records, this May has been one for the history books for Mumbai. After experiencing light to moderate showers from the second week of the month, monsoon arrived in Mumbai with a bang on May 26, making it the earliest recorded onset in the past 75 years. With the city experiencing an early arrival of monsoon, Shubhangi Bhute, Director, IMD (Mumbai) and head of Regional Meteorological Centre for Western India, spoke to The Indian Express about the factors influencing the early arrival and what Mumbai can expect going forward. Here are the edited excerpts: Q: This year, May has been unique for the city. Why did we see such heavy pre-monsoon showers, and what led to the earliest onset of the monsoon in the past 75 years at least? Shubhangi Bhute: In May, we did not see any rise in temperatures, with temperatures remaining normal and sometimes, because of rainfall activity, we have also seen that the temperatures have dropped to 32 degree Celsius as well. This month, monsoon also set into Mumbai well in advance, making it the earliest onset in the last 75 years. Earlier, there have been only five occasions (years) when the monsoon set in May, on May 31 and May 29. As well predicted, conditions were very favourable for the early onset. This year, monsoon had set into Andaman well in advance by May 13, then it set over Kerala by May 24, and then reached Maharashtra by May 25. The monsoon onset is declared when all the criteria for the declaration are met, and these include many factors about rainfall requirements, wind field, Outgoing Longwave Radiation (OLR), among others. Besides that, Madden-Julian Oscillation (MJO) is also one of the key contributors. Earlier, MJO was in the eighth phase, and now, it is in the second phase, which is favourable for good monsoons in the Indian region. Furthermore, the neutral phase of El Niño-Southern Oscillation (ENSO), and neutral El Niño are also present. And altogether, these factors have led to the early onset of monsoon in the Indian region. Q. This time, we saw that the monsoon arrived in Mumbai very quickly, merely two days after it entered Kerala. This is in stark contrast to the normal timeline of at least 10 days. Bhute: We saw that the monsoon advanced very fast. After reaching Andaman on May 13, it entered Karwar almost a week in advance. It reached Karwar and Belgaum by May 24, and then within two days, it reached Mumbai by 26th May. Besides meeting the basic conditions for the declaration of monsoon in Kerala, the monsoon advancement also depends on two branches — the Arabian Sea and the Bay of Bengal branches. If the Arabian Sea branch on the western coast is very active, with active systems like low-pressure areas, then the southwest monsoon starts setting in from the Arabian Sea side. However, currently, the Bay of Bengal side is very lull. This means that there is no system in the Bay of Bengal to pull the moisture, therefore, monsoon advancement has been delayed on the eastern side. Once a low-pressure area forms in the eastern branch of the Bay of Bengal, the winds will be pulled, and the monsoon will also be covered on the other coast. Presently, while the Bay of Bengal branch was lull, the Arabian Sea was very active with a low-pressure area, which contributed to the pulling in of moisture from the ocean to land. This further contributed to the early advancement of monsoon. Q: Several reports and weather observers have suggested that after the early advancement, there will be a lull in showers. What does this mean? Will the rains discontinue now? Bhute: The timeline of the monsoon doesn't matter. Even if the monsoon were to arrive in June, ahead of schedule or even if it had been delayed, it is not necessary that the city would receive heavy rains every single day. Rains during monsoon are not continuous, simple or steady, as they always depend on the systems. There will always be a variation in the quantum of rain, and there may even be days when no rainfall is registered. In Mumbai, generally August is seen as the month of dry spell when there is the least rain, and July is the wettest monsoon period, while June is the month of onset. Now that the monsoons have arrived early in May, we will observe the rain patterns this month. Q: This year, IMD has forecast above normal rains all over the country. What does this mean for Mumbai? Bhute: In the Long Range Period forecast, IMD's chart has indicated that above-normal rainfall is very likely along the west coast, particularly around the Maharashtra region. This suggests that the percentage of possibility of excess rainfall is more even in Mumbai. Q: Does this mean Mumbai can see more flash floods, as we observed on May 26 with the arrival of monsoon? Bhute: The patterns of monsoon have now changed as we receive heavy rains within a short period. While we cannot say right now whether the frequency of flash floods will be higher, we can definitely expect many days where we will receive 'heavy to very heavy rain'. As per the IMD's forecast for this season, a higher frequency of rainy days is very likely, as we can expect more 'heavy to very heavy rainfall' type of days in Mumbai. Q: IMD often draws flak for failing to issue timely forecast warnings and alerts. What makes forecasting a challenging task in a city like Mumbai? Bhute: First of all, we are in a tropical region where the frequency of weather changes is very fast. Now, in the monsoons, we expect rains from the southwesterly winds, and that has to be supported by upper air winds. While generally we get rains because of southwesterly winds, which bring moisture, and we get the convection of the rains, the changes in wind patterns and other systems happen at the micro level. Mumbai is only a 40 to 60 km patch, which is in the Arabian Sea. Compared to the larger state of Maharashtra, it is a very small stretch. It is very difficult to forecast for such a small stretch, as sub-kilometre mesoscale models are unavailable. Besides being in the tropical zone, Mumbai's proximity to the sea also means that the weather changes very rapidly. On land, we observe fixed patterns where systems generally move in a very particular manner. But in Mumbai, we will see that some parts receive rain while the other parts may remain dry and even sunny. Furthermore, while we predict and issue forecast warnings on the basis of synoptic conditions one day in advance, changes happen very fast within half an hour or in hours. Even if we look at May 26, extremely heavy rainfall occurred only in South Mumbai, while the rest of the suburbs experienced much less rain during the daytime. Within two days, the Colaba station received more than 250 mm of rainfall while the Santacruz station recorded heavy showers on the second day. Whenever we issue orange or red alerts, we mention the likelihood of rain in isolated pockets, as it is very unlikely that the entire city would receive heavy rain. Q: What is the system of issuing red alerts? Sometimes, red alerts are issued when the intensity of rain relaxes or the showers discontinue after a red warning is sounded. Bhute: For red warnings, we generally follow the orange alert. While we forecast heavy rainfall for an orange alert, the city may likely experience extremely heavy rainfall for only two hours, after which it may dry up. On May 26, too, we had issued forecasts with orange and then, red alerts, indicating that the city would receive heavy rain during the first half, following which the intensity would reduce. However, we issue our forecast warnings for a period of 24 hours, as immediately removing the red alert is not ideal. Even if the system relaxes and rains have reduced, we keep our warnings for a 24-hour period, as the systems can always intensify and bring heavy rain again. Often, it also happens that we issue our red alerts 24 hours or 48 hours in advance, but sometimes the systems can change very fast. Furthermore, it is not easy to withdraw a red alert immediately after it is issued. Our objective is that the administration and the public should not be in trouble or underprepared. If there is a possibility of rain, we can always overwarn rather than underwarn, as there should not arise a situation where our underwarning leads to a lack of adequate preparation or there is an adverse situation or mishap. Sometimes, even if we are expecting heavy rain, which can be categorised as orange, we do not remove our red alert, as extra precaution is always better.
Indian Express
7 days ago
- Climate
- Indian Express
This Word Means: Madden-Julian Oscillation
While the southwest monsoon arrived in Kerala on May 24, eight days earlier than the normal onset date, it reached Mumbai two weeks in advance on May 26. This was also the earliest the monsoon arrived in Mumbai on record. Several large-scale atmospheric-oceanic and local factors developed and favoured the early monsoon onset but one of the key drivers was the Madden-Julian Oscillation (MJO), according to the India Meteorological Department (IMD). What is MJO? The MJO is a moving system of winds, cloud, and pressure that brings rain as it circles around the equator. The phenomenon takes its name from the two scientists who identified it in 1971 — Roland Madden and Paul Julian, who then worked at the National Centre for Atmospheric Research in Boulder, Colorado. The system typically travels eastward at a speed of 4-8 metres per second. It goes around the globe in 30-60 days on average, but can sometimes take 90 days. As it moves, strong MJO activity often splits the planet into two parts — one in which the MJO is in active phase and brings rainfall, and the other in which it suppresses rainfall. In the active phase, MJO results in higher-than-average rainfall for that time of the year, while in the suppressed phase, the area receives less than average rainfall. An active phase is generally followed by a weak or suppressed phase, in which there is little MJO activity. The effect of the MJO is witnessed mainly in the tropical region, in the band between 30 degrees North and 30 degrees South of the equator, even though the mid-latitude regions in both hemispheres also feel its impact. India falls in this band. As the MJO cycle lasts only 30-60 days, there can be multiple MJO events in a season. There is some evidence that the MJO and El Niño — the unusual warming of sea-surface Pacific waters off the South American coast — are correlated. Thus, strong MJO activity, like this year, is witnessed in a year of strong El Niño. However, the correlation is not exclusive: a strong El Niño year — the strength being a measure of the increase of temperature of sea surface water — is generally associated with a bad monsoon. How did the MJO contribute to the early monsoon onset? In the tropics, MJO in its active phase brings frequent cyclonic activity, and can initiate the onset of the monsoon. For instance, in June 2015, the MJO resulted in about 20 days of very good rainfall in most parts of the country. This is what could have happened this year as well. That is because around May 22, the MJO, which had originated in the Indian Ocean, was in Phase 4 with an amplitude greater than 1, which is indicative of strong rainfall and storms, according to IMD's extended range forecast.
Yahoo
28-05-2025
- Climate
- Yahoo
Tropical outlook quiet to start Atlantic hurricane season, but there may be a window for potential
As June ushers in the official start of the Atlantic basin hurricane season, attention is once again turning to the tropics in search of the first signs of development. Similar to patterns observed over the past three years, the season is expected to begin on a quiet note, with no named storms forecast to form in the opening days of the month. However, the big question is whether the rest of June will follow suit. To help answer that question, forecasters often consult a variety of products, including tracking what is known as the Madden-Julian Oscillation, or what is commonly called the MJO. This eastward-moving pulse of enhanced rainfall and lower atmospheric pressure typically circles the globe every 30 to 60 days and can significantly influence tropical weather patterns. The Mjo is divided into eight phases, each affecting different regions of the globe. When the MJO is in phases 8, 1 or 2, it generally leads to enhanced activity over the Atlantic basin and, if other conditions align, can increase the chances of tropical cyclone formation. Pattern Emerges In Tropics For First Time In More Than 20 Years Because of the MJO's current location and timing, forecasters expect only one favorable window for development in the Atlantic basin during June. This period is likely to occur in the second half of the month, and the Caribbean and the Gulf are the most probable areas of interest. This region is climatologically favored for development due to the presence of features that can aid in the formation of tropical cyclones, such as old frontal boundaries or the Central American Gyre, a large area of lower pressure. The latest outlook from NOAA's Climate Prediction Center points to a potentially favorable environment for tropical development during weeks two and three of the month. While the outlook does not guarantee a named storm will form, it will lead to increased tropical moisture over Central America, Mexico, and possibly as far north as the Gulf Coast. By late June and early July, atmospheric conditions may again become less conducive to development as the MJO continues its eastward progression around the globe. 2025 Atlantic Hurricane Season Guide: Here's What To Know About The Tropics This Year The formation date of the season's first named storm can be an important indicator of what's to come. Statistically, when the first named storm forms before June 20, it often signals a more active season ahead. On the other hand, if the season reaches early July without a named storm, it may serve as an indicator of a quieter-than-average year. The last time the first named storm formed on or after June 20 was in 2014, when Arthur developed on July 1. The year ended up being relatively subdued, with only eight named storms, six hurricanes and two major hurricanes - all well below the seasonal averages. Although the Atlantic hurricane season officially runs from June 1 to November 30, losing the entire first month to inactivity effectively removes more than 16% of the season's duration. This lost time cannot be regained later in the year, as water temperatures typically decline and atmospheric stability increases, making storm formation less likely. So, while the start of the 2025 hurricane season appears tranquil, forecasters will be closely monitoring the MJO and other key indicators in the coming weeks for any early hints of article source: Tropical outlook quiet to start Atlantic hurricane season, but there may be a window for potential
