Weather Update: Thunderous Winds and Western Disturbance Trigger Rain and Cold Wave in Delhi-NCR, AQI Likely to Improve

As January draws to a close and February approaches, Delhi-NCR witnessed a sharp change in weather on Friday, with heavy rain accompanied by strong, chilly winds. The Indian Meteorological Department’s (IMD) forecast has proved accurate, bringing much-needed relief from severe air pollution while also intensifying the winter chill across the region.

Early Friday morning, several parts of Delhi and the National Capital Region experienced rainfall along with gusty winds, signalling a fresh dip in temperatures. After an unusually warm spell earlier in the week, the mercury is expected to fall again, making the cold more pronounced in North India.

Western Disturbance Behind the Weather Shift

According to the IMD, the sudden change in weather is due to an active Western Disturbance affecting North India. Since the early hours of Friday, dense cloud cover and widespread rainfall have been observed, with meteorologists warning that more rain is likely later in the day.

The IMD has issued alerts for heavy rain, thunderstorms, lightning, hailstorms, and strong winds in parts of nine states. Wind speeds of up to 65 kmph have been reported. The department has also warned of heavy snowfall in the Western Himalayan region and cold wave conditions in 17 districts across North India on January 22 and 23.

What Is a Western Disturbance?

A Western Disturbance is a weather system that originates over the Mediterranean region and travels eastward, bringing moisture from the Mediterranean, Atlantic, and sometimes the Caspian Sea. During winter, it causes sudden rainfall and snowfall over North India, Pakistan, and Nepal, leading to snowfall in the Himalayan regions. These systems are crucial for rabi crops such as wheat, as they provide essential winter rainfall.

Snowfall Ends Dry Spell in the Hills

Meanwhile, Shimla received its first snowfall of the season on Friday, ending a dry spell that had lasted nearly three months. Snowfall has also been reported from other hilly areas of Himachal Pradesh, including Manali. Several parts of Jammu witnessed rainfall, with cold conditions continuing to grip the region.

Rain and Winds to Improve Air Quality

Delhi’s air quality had already shown marginal improvement on Thursday, with the average Air Quality Index (AQI) recorded at 313 (very poor) at 8 am, compared to 330 on Wednesday evening. With increasing wind speeds and ongoing rainfall, pollutants are expected to settle, leading to further improvement in air quality across the capital.

What Is ‘Roaring Forties’ (Garajta Chaleesa)?

The term “Roaring Forties” refers to the powerful westerly winds that blow between 40° and 50° south latitudes in the Southern Hemisphere. Coined by sailors, these winds move from west to east and are driven by atmospheric circulation and the Earth’s rotation. Due to the absence of large landmasses in this belt, the winds remain largely unobstructed, making them exceptionally strong.

Historically, sailors travelling from Europe to Australia used these winds to speed up their eastward voyages, despite the rough sea conditions they often created.

No Direct Link Between Roaring Forties and Western Disturbance

Weather experts clarify that there is no direct connection between Western Disturbances and the Roaring Forties. While Western Disturbances originate in the Northern Hemisphere and bring winter rain to the Indian subcontinent, the Roaring Forties are a Southern Hemisphere phenomenon confined to oceanic regions.

For now, the rain and cold winds have brought both relief from pollution and a renewed chill to Delhi-NCR, with residents advised to stay prepared for colder days ahead.