The Hindu Business Line : Westerly trough triggers rains in N-W

The western Himalayan region has been experiencing fairly widespread precipitation over the past three days as the first of a series of weather-creating seasonal western disturbances crossed into the region.

The proceedings will get a further boost when, as has been forecast already, the second and the a deeper disturbance rolls into the region in another two days with a sweep that engulfs the whole of the northwest border, even reaching northern Gujarat.

TO DRIVE UP RAIN

An India Meteorological Department (IMD) update on Monday said this would help drive up the intensity of the precipitation with heavy to very heavy snowfall forecast for Jammu and Kashmir and Himachal Pradesh. Adjoining plains of northwest India are also likely to experience isolated to scattered rain/thundershowers during the period.

In this manner, rain or snow is likely at a few places over Uttarakhand. Rain or thundershowers are also likely at a few places over Punjab, north Haryana and Chandigarh, including Delhi, while being isolated over the rest of the region. Isolated rain/thundershowers are likely over north Rajasthan, Saurashtra and Kutch as well.

FOG LIKELY

Fog conditions are likely to develop over the Indo-Gangetic plains during the next 1-2 days, the IMD forecast said. The cloud cover associated with the western disturbance has already led to a spiking of the minimum temperatures by 2-4 degree Celsius above normal over northwest and central India.

Night temperatures may further rise by 2-3 degree Celsius till Thursday in tandem with the arrival of the bigger western disturbance, but would fall thereafter as the rear of the system, marked by sinking and cold air, lets in the cold northwesterlies.

Westerly systems affecting the remote north or northwest India have been either ‘shallow’ in extent or ‘hollow’ in intent till now, during the season denying moisture influx into the region and the rainfall it triggers. Only those systems endowed with the right ‘sweep’ can undergo intensification over the northwest by pulling in moisture from the Arabian Sea, and in rare cases, even the Bay of Bengal. This intensification throws up an induced ‘low’ in the region, which spearheads the rainfall session.

GODSEND FOR FARMERS

The rains are a godsend for farmers even in the irrigated lands since not only would these help accelerate the growth of the plants but also bring down the cost of irrigation, especially in those areas where groundwater is used for the purpose. North Rajasthan, western Uttar Pradesh and Haryana are examples.

But those in the rain-fed farmlands can only curse their luck this time round since the unprecedented dry winter had severely curtailed Rabi sowing operations in many parts of the northwest and central India.

More Stories on : Climate & Weather | Climate & Weather

Article E-Mail :: Comment :: Syndication :: Printer Friendly Page