Why Delhi is dry despite heavy rain in Uttar Pradesh, nearby areas

The primary reason why Delhi is dry lies in the middle tropospheric dry air advection from the northwest, which has been preventing the formation of rain-bearing clouds over the city. Advection refers to the horizontal transfer of air.

In Short

• Delhi dry due to middle tropospheric dry air advection
• Dry air prevents rain-bearing cloud formation
• Low-level moisture insufficient for precipitation

While many parts of India are receiving ample rainfall, Delhi has been conspicuously dry. The primary reason lies in the middle tropospheric dry air advection from the northwest, which has been preventing the formation of rain-bearing clouds over the city.

Advection refers to the horizontal transfer of air, and in this case, dry air from the northwest is being pushed into Delhi’s middle troposphere. This dry air essentially acts like a barrier, hindering the vertical development of clouds which are necessary for precipitation.

Adding to this is the presence of anticyclonic middle-level vorticity over the region. Vorticity refers to the rotation of air in the atmosphere. An anticyclonic vorticity signifies a clockwise rotation which is often associated with descending air. When air descends, it tends to warm up and dry out, further contributing to the suppression of cloud formation and rainfall.

The available low-level moisture in Delhi is therefore not enough to overcome these unfavourable conditions. Low-level moisture alone can lead to cloud formation, but without the requisite uplift which is being stifled by the aforementioned factors, these clouds cannot mature into rain-bearing cumulonimbus clouds.

As a result, despite the low-level moisture, the combined effects of middle tropospheric dry air advection and anticyclonic vorticity ensure a rain shadow over Delhi. The situation is complex and highlights the nuanced interplay of various meteorological factors that determine weather patterns.

Hence, the overall scenario can be summed up. While the low-level moisture might create hopeful conditions for rain, the overarching presence of dry air and anticyclonic vorticity in the middle troposphere forms an effective blockade, ensuring that Delhi remains dry. These factors underline the intricate dynamics of atmospheric science and the challenges in weather prediction.

3 systems bring rain in Central, North India. Know how they work

Three distinct meteorological systems are currently influencing the weather dynamics in North and Central India, each contributing to varying patterns of rainfall and temperature across the region. These systems include a Mid-Tropospheric Cyclone (MTC) in interior Maharashtra, a Low-Pressure System (LPS) in Uttar Pradesh, and a Western Disturbance in the Himalayan region of the Northwest.

The Mid-Tropospheric Cyclone (MTC) has recently moved further into interior Maharashtra. As a result, the previously heightened rainfall in Gujarat and Maharashtra is expected to decrease. Conversely, regions like Madhya Pradesh (MP) will witness an uptick in precipitation due to the MTC's current trajectory.

Simultaneously, the Low-Pressure System (LPS) has progressed towards central Uttar Pradesh. This movement is likely to escalate rainfall in areas such as Nepal, the northeastern parts of Uttar Pradesh, and North Bihar. The LPS plays a critical role in directing moisture-laden winds toward these regions, contributing to more concentrated and widespread rainfall.

Adding another layer of complexity to the weather patterns is a Western Disturbance in the Himalayan region, particularly affecting the Northwest. Western Disturbances are crucial in bringing winter rain and snow to the Himalayan states. This disturbance is expected to trigger precipitation across the mountainous terrain, potentially resulting in significant snowfall in higher altitudes and rain in the lower elevations of the northern Indian subcontinent.

The confluence of these three meteorological phenomena underscores the intricate and interlinked nature of weather systems. Each contributes uniquely to the overall climate scenario, impacting agriculture, water reservoirs, and general livelihoods