Newswise — A recent study has revealed that by employing weather forecasting methods currently utilized in India, Sri Lanka could enhance its ability to predict floods and landslides. This research holds promise in aiding communities to effectively brace themselves for instances of intense rainfall on the South Asian island. Sri Lanka remains highly susceptible to devastating floods and landslides due to the impact of heavy rainfall. In a tragic event in May 2017, over 150 lives were lost as the country endured severe flooding triggered by monsoon rains.
In a recent publication on Thursday, 27 July, in Geophysical Research Letters, Dr. Akshay Deoras led a study that signifies a significant expansion of countries benefiting from the University of Reading's research support. The study underscores the critical importance of investigating extreme weather occurrences in Sri Lanka.
Dr. Deoras emphasized that Sri Lanka has not received sufficient attention from researchers, despite its high vulnerability to catastrophic floods and extreme weather events, which are expected to exacerbate in the future due to climate change. This groundbreaking study demonstrates that the weather forecasting techniques already employed in India can also be successfully utilized in Sri Lanka.
Meteorologists, responsible for weather forecasting, diligently observe significant wind patterns that play a pivotal role in predicting future weather conditions. Through our research, we have pinpointed particular wind patterns that primarily contribute to the occurrence of intense rainfall in Sri Lanka. This crucial understanding of the connection between weather patterns and extreme rainfall holds immense importance in assisting Sri Lankan communities to effectively prepare and respond to life-threatening natural disasters, potentially leading to life-saving outcomes.
Prediciting extreme rainfall
A monsoon climate is distinguished by a striking seasonal shift in the prevailing winds' direction across a specific region. The research unveiled that Sri Lanka witnesses the highest frequency of extreme rainfall during the northeast monsoon (December-February) and second intermonsoon seasons (October-November). Conversely, weather patterns associated with the southwest monsoon (May-September) and first intermonsoon (March-April) seasons experience significantly lower amounts of rainfall.
By analyzing various datasets, the research team delved into the association between extreme rainfall in Sri Lanka, weather patterns, and the Madden-Julian Oscillation (MJO). The MJO, an eastward moving system of clouds and rainfall over the equatorial Indian Ocean and western Pacific Ocean, exerts influence on tropical weather. The researchers discovered that the positioning of the MJO plays a crucial role in determining whether a weather pattern will trigger intense rainfall in Sri Lanka.
Notably, the likelihood of extreme rainfall in certain weather patterns significantly increased when the MJO was situated over the Indian Ocean, while it decreased by over 90% for the same weather patterns when the MJO was positioned over the western Pacific Ocean.
Given that leading weather prediction models can accurately forecast the location of the MJO approximately a week in advance, the study's findings hold promise in augmenting the predictability of extreme rainfall in Sri Lanka, owing to its connection with the MJO. This improved understanding can prove invaluable in better preparing for and responding to extreme weather events in the region.
RSS