Western Disturbances and Their Impact on India
Western Disturbances (WDs) are an important group of weather systems that cause a considerable effect on the climate of India, more so in winter. Although the western disturbances are largely focused upon northern India, indirect effects can be found as far south as Kerala also. In order to understand their role in forming the weather all over the country, let’s look upon what these western disturbances are, how they function, and what impacts are seen upon different regions of India.
What Are Western Disturbances?
The Western disturbances are a low-pressure system that originates in the Mediterranean region. with the help of the subtropical westerly jet stream. It travels to the east. This can be seen as a fast-moving stream of air in the upper atmosphere. These systems commonly carry moisture from the Mediterranean, Caspian, and Black Seas and affect weather conditions over Iran, Afghanistan, Pakistan, and northern India.
They are important during winter, that is, December, January, and February, but can be felt at other times during the year.How Do Western Disturbances Work?As the western disturbances move over the Indian subcontinent, they pass over the Himalayan Mountain range. The Himalayas act as a natural boundary; they make the air rise, cool, and condense, giving rise to clouds and hence precipitation. The precipitation may be in the form of rain, snow, or even hail depending upon the temperature and the altitude.
These disturbances show specific features as follows
Vertical Form: WDs are steeply tilted with height, and hence, their upper and lower atmospheric levels are displaced.
Moisture Content: They carry moisture from far-off seas, making it capable of delivering heavy rainfall.
Speed and Intensity: Their effect depends on the position and strength of the jet stream, which differs year-wise.Impact on Northern IndiaNorthern India, which includes the states of Punjab, Haryana, Rajasthan, and Uttar Pradesh, is the main recipient of western disturbances in the country. The systems provide much-needed winter rain and snowfall to the region. The precipitation is critical for agriculture, particularly rabi crops such as wheat and mustard, which depend on it.
Other than these advantages, western disturbances also bring extreme weather events such as:
Heavy Rainfall: At times leading to flash floods.
Hailstorms: Damage to crops and structures.
Cold Waves: Delaying End Winters.All these effects explain the two extremes of western disturbances, both as boon and sometimes bane.
Influence on Kerala
Though Kerala lies away from the main zone of western disturbances, these systems can indirectly influence its weather. Western disturbances affect the larger atmospheric conditions over the Indian subcontinent, which further affects the state’s weather.
Disruption of the Monsoon Winds: Seldom, WDs cause disruptions in the normalcy of winds during the north-east monsoon season (Oct-Dec), causing irregular Kerala rainfalls.
Dry Spells: Occasional dominance of the western disturbances in northern regions reduces moisture availability in the south and leads to dryness.
Unseasonal Rainfall: Sometimes, the leftovers of the weak western disturbances combine with other local weather systems and create unseasonal rainfall in Kerala. Climate Change and Western Disturbances Generally, climate change is showing changes in the weather patterns throughout the world. Western disturbances are one of them.
Studies in this regard indicate that extreme western disturbances are on the rise, which cause intense showers or snowfall.The subtropical westerly jet stream could potentially influence the timing and trajectory of WDs. According to studies, the future global warming will decrease snowfall and increase rainfall corresponding to WDs.
Such changes may have significant implications in agriculture, water resources, and disaster management across the nation. Prediction and Prior PreparationsWeather forecasting for western disturbances involves monitoring through advanced tracking algorithms and satellite data.
Prediction of their track and intensity can be made to provide warnings and prepare the people in advance for potential effects. For example:In northern India, irrigation schedules may be planned, or crops may be protected from hailstorms. Kerala may manage indirect effects more effectively and anticipate unseasonal rainfall to manage water resources.
Conclusion The western disturbances are an integral part of the weather system in India. Although their direct effects are seen in northern states, they can influence the southern region also, like Kerala, under certain conditions. Therefore, knowing these phenomena and their impacts at a larger level can help India better prepare for their benefits as well as challenges.
The changing weather patterns due to climate change will only make studying and predicting western disturbances more important. This knowledge is an important tool for the safekeeping of agriculture, sound management of water resources, and mitigation of extreme weather across the country.
