Western Disturbances and Their Impact on Weather

Recent weather patterns in India have been influenced by an incoming western disturbance. This disturbance has developed into a cyclonic circulation over northern Pakistan, affecting atmospheric dynamics across the region. The India Meteorological Department (IMD) has forecasted a series of violent weather events across East India, East-Central India, and South Peninsula due to this phenomenon.

About Western Disturbances

Western disturbances are weather systems that originate in the Mediterranean region. They travel eastward and bring moisture to the Indian subcontinent. These disturbances are crucial for winter rainfall in North India. Their impact is most pronounced during the winter months but can also influence weather patterns in other seasons.

Current Weather Forecast

The IMD has predicted widespread moderate rainfall, thunderstorms, and gusty winds across various regions. North-East India is expected to experience heavy rainfall, particularly in Assam and Meghalaya, for several days. The norwester season, locally known as Kal Baisakhi, is expected to gain momentum due to the influence of the western disturbance.

Regional Impacts

The cyclonic circulation has led to the formation of multiple weather troughs. A trough of lower atmospheric pressure extends from north-west Rajasthan to east Bangladesh. Another trough runs diagonally from north Chhattisgarh to the Gulf of Mannar. These troughs will result in scattered to moderate rainfall across southern states like Karnataka, Andhra Pradesh, Kerala, and Tamil Nadu.

Weather Dynamics

The dynamics of the atmosphere are altered by these disturbances. The IMD noted that isolated thunderstorms and gusty winds are likely in various parts of North-West India. Early indications suggest that a high-pressure area may form towards the end of the month, which could inhibit the movement of western disturbances.

Future Weather Patterns

As the month progresses, the potential for severe weather remains high. The IMD has warned of possible thunderstorms and high winds extending from the eastern seaboard to the southern regions. This could lead to hazardous conditions across multiple states, necessitating preparedness measures.

Significance of Monitoring

Monitoring western disturbances is vital for disaster management and agricultural planning. Accurate forecasts help mitigate the adverse effects of severe weather, ensuring timely response and preparedness. About the patterns of these disturbances can aid in predicting their impacts on monsoon and seasonal weather.

Questions for UPSC:

1. Critically analyse the role of western disturbances in the Indian monsoon system.
2. What are the implications of climate change on the frequency and intensity of western disturbances?
3. Point out the effects of cyclonic circulations on regional weather patterns in India.
4. Estimate the impact of extreme weather events on agricultural productivity in India.

Answer Hints:

1. Critically analyse the role of western disturbances in the Indian monsoon system.

1. Western disturbances originate from the Mediterranean and bring moisture to the Indian subcontinent.
2. They are crucial for winter rainfall, especially in North India, influencing the overall monsoon pattern.
3. They contribute to the formation of rain-bearing clouds, enhancing precipitation during the monsoon season.
4. Western disturbances can also lead to sudden weather changes, affecting agricultural practices.
5. The interaction with local weather systems can intensify rainfall, impacting flood dynamics and water resources.

2. What are the implications of climate change on the frequency and intensity of western disturbances?

1. Climate change may alter atmospheric temperatures and humidity, impacting the formation and movement of western disturbances.
2. Increased global temperatures can lead to more intense and frequent disturbances, affecting weather patterns.
3. Changes in ocean temperatures can influence the moisture carried by these disturbances, potentially increasing rainfall intensity.
4. Altered weather patterns may lead to increased unpredictability in monsoon onset and duration.
5. Regional climate variability could exacerbate droughts or floods, impacting agricultural and water resource management.

3. Point out the effects of cyclonic circulations on regional weather patterns in India.

1. Cyclonic circulations can lead to changes in local atmospheric pressure, causing varied weather conditions.
2. They are associated with heavy rainfall, thunderstorms, and gusty winds in affected regions.
3. These circulations can disrupt normal weather patterns, leading to extreme weather events.
4. The interaction with other weather systems can create complex weather dynamics, affecting multiple states simultaneously.
5. Monitoring these circulations is essential for timely weather warnings and disaster preparedness.

4. Estimate the impact of extreme weather events on agricultural productivity in India.

1. Extreme weather events, such as heavy rainfall and thunderstorms, can lead to crop damage and soil erosion.
2. Flooding can inundate fields, delaying sowing and harvesting, impacting food supply chains.
3. Prolonged droughts or irregular rainfall patterns can lead to water scarcity, affecting irrigation and crop yields.
4. Farmers may face increased financial risks and losses due to unpredictable weather, affecting livelihoods.
5. Adapting agricultural practices and improving resilience is essential for mitigating these impacts on productivity.