‘August rainfall could be below normal’
6 min read 03 Aug 2023, 10:45 PM ISTSkymet managing director Jatin Singh in an interview said August rainfall could be below normal at around 90% LPA, thus, causing dry weather.
PremiumNew Delhi: After 28% plus excess rainfall last month, August is expected to be dry, as precipitation will likely be below normal at around 90% of the long period average (LPA), said Jatin Singh, managing director of private weather forecaster Skymet in an interview.
The government’s India Meteorological Department has already predicted August rainfall to be below normal and at a 94% LPA. Skymet has retained its monsoon forecast at 94% LPA with an error margin of 5% for the entire four-month season. Extreme weather patterns have resulted in surplus rain in the northern region and deficiency in eastern India that generally receives the highest average precipitation in the country. Eastern and northeastern India that have received 23% less rainfall than normal, are likely to get to monsoon showers in the first week of August, and rainfall could be normal to above normal, Singh said. El Nino, which is still in an evolving phase, is expected to gain strength throughout the monsoon season, pushing sea surface temperatures (SST) to 2-degree celcius and disrupt rainfall in August and September, he added.
Singh said ocean temperatures are rising rapidly due to climate change resulting in even Delhi being affected by a cyclone formed in the Arabian Sea, causing a flood-like situation. Ocean observations need to be improved for better weather forecasting beyond 7-10 days, as relying on satellite images is not enough, he aded. Edited excerpts:
How do you see the monsoon behaving in August?
There is a level of uncertainty in prediction and distribution has got distorted. For example, North India is still excess of 26%, more than South and Central, though it should be the other way round. Average precipitation in North India is relatively lower, whereas East India gets the highest average rainfall as compared to the other regions. East India is the poorest right now in terms of precipitation.
Rainfall patterns are very random. Many people argue this is due to climate change and it is difficult to establish. One thing is clear: in the context of climate change, we are witnessing a tremendous amount of extremity in terms of sway. Both central and southern India were in deficit and now Mumbai has got 97% of the season’s average rainfall already. Predictions in August might not be very good. August is one of the core monsoon months and the total quantum of rainfall in August is equal to July. August rainfall could be below normal at around 90% LPA, thus causing dry weather.
Climate Forecast System this year consistently has been showing a below-normal rainfall sign, but July rainfall is +28%. There is a tremendous volume of water. And August is expected to see significantly dry weather. A similar situation happened in 2009 when it stopped raining in August. So far, we retain our monsoon forecast at 94% with an error margin of +/-5%.
What are the latest developments with El Nino?
Despite the sea surface temperature being above normal at the moment in the ocean, one region is not in sync with Southern Oscillation and El Nino conditions just commenced. El Nino is building up and the alert is there now, meaning in the coming days, El Nino event will reflect. It will develop and it will be fully blown, and the impact will be felt this year. It will cause more harm to the rainfall in the second half of the monsoon.
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El Nino is evolving and will become more and more severe as we go through the season. Therefore, we said in our forecast that the second half is to be watched carefully as it may cause more damage in the second half. El Nino disrupts rainfall distribution.
Sometimes it brings excess precipitation as well, but the area is very small. Large pockets get scanty rain. El Nino reduces the quantitive rainfall, and the quality also gets impacted. It is a monsoon disruptive phenomenon, which invariably brings drought to Indian sub-continent, but every time drought-like situation may not emerge. Invariably, it leads to a below-normal monsoon or 80% of the time, it led to a below-normal monsoon; of which 60% have seen droughts. We will possibly see its impact in August and September when rainfall is expected to be less.
As far as Indian Occean Dipole (IOD) is concerned, it was negative till the second last week. Last week it became neutral for the first time. El Nino has a threshold value of +/- 0.5 degree. Like El Nino, IOD also has a threshold value of +/- 0.4 degree. If it is between +/-0.4, we call it neutral. It went up to even –0.35 degrees. It means it is a fluctuating index as of now. There is no certainty that IOD will become positive. It may or may not. In any case, IOD linkage with the southwest monsoon is very poor unlike El Nino, which has a strong connection and proven record impacting Indian monsoon adversely.
Australian Meteorology Department predicted SST across the equatorial Pacific Ocean may warm by 3.2 degrees Celsius by November. What is your view in Indian context?
Australia is in the southern Emisphere, and we are at the north Emisphere. Unlike India, Australia does not get impacted during June-September because of seasonal difference. They will get impacted in monsoon when India will be entering into winter months. El Nino impact in India is more significant now because the temperature now is 1.1 degree above the average and may rise to 2 degrees Celsius during the monsoon season itself.
Why are cyclones frequent in Arabian Sea these days?
Water has become warm, especially in Arabian Sea. The last cyclone near Mumbai was 1951 and now the cyclone patterns in Arabian Sea have changed. Earlier, cyclones in Arabian Sea before monsoon would go towards West Asia. This time cyclone came all the way to Delhi. So, warmer oceans have changed cyclone patterns.
People think that they know what climate change is, but we don’t know. Some people say that heat will cause dryness but according to earth science, heat could lead to evaporation and consequently thunderstorms. The conclusion you can draw is extreme weather. Till mid-June, precipitation in the country was not there and suddenly in two weeks it made up 90% of June and in July it went up about 30%. I fear in August it might significantly come down. The problem has become the uneven distribution of rainfall.
We often see monthly and seasonal predictions going wrong? How can forecasts be improved?
This is an institutional set-up, which is followed by the entire world. We don’t have enough observations of the ocean and we don’t understand land ocean interaction from the season’s perspective as much as we should. I think the problem is people tend to work depending on satellites that have an issue in terms of resolution observation. The world needs to invest in a technology that can cover sky and down till the bottom of Oceans. Even the ocean has multiple layers. We need to observe how water is going up and down and currents in the ocean are moving and the world needs to correlate it together.
We have recently introduced Skymet AI (artificial intelligence), which we believe could be a groundbreaking advancement in weather intelligence technology. With this technology, we will be able to provide real-time weather insights and forecasts, tailored to the specific needs of users. Whether you are a farmer seeking agricultural guidance, a daily commuter planning your route, a traveller preparing for a journey, or an outdoor enthusiast exploring the elements
