Northwest and northeastern states have had an unusually wet January, with Manipur receiving 1603% of the normal rainfall for the month, according to the India Meteorological Department (IMD) data. India has so far received 120% of the rainfall usually recorded till the third week of January.
Uttrakhand, Uttar Pradesh and Punjab have received over 300% of the normal precipitation in January. In the northeast, Tripura has received 670% of the normal rainfall and Mizoram 295%.
“So far, the precipitation in many states has been two to three times the normal. Most of the rainfall in the northern and north-western parts of the country this month is under the influence of western disturbances (WD). And, this month there have been a higher than usual number of WDs, with the one that is likely to bring precipitation to the Himalayan region this Tuesday being the fifth one. There are predictions of three more WDs that are likely by the end of this month, taking the total number to eight,” said RK Jenamani, senior scientist, IMD.
A WD is a storm originating in the Mediterranean region that brings winter rains to the north-western parts of the Indian subcontinent. “Usually, we just see about three WDs in January. This year, when we talk about precipitation due to the WD, there have been more snowfall events than rainfall,” said Jenamani.
Between January 1 and January 19, half of all the districts monitored by the IMD have had large precipitation.
The IMD forecast has predicted heavy rain or snowfall over Jammu and Kashmir. This might also bring a cloudy day, some drizzle or very light rain to Delhi late at night, according to the IMD. So far, Delhi has received 17.5 mm of rainfall till January 19, instead of the normal 8.2mm creating a large excess of 114%.
“This is very unusual. This year the intensity and number of the WDs have been exceptionally high. There have been successive WDs without any significant gap; not more than two or three days. Whenever the WDs reach the Himalayas, they create cyclonic circulation over the northern plains that travel west to east bringing winter rain to the entire Indo-Gangetic plains,” Mahesh Palawat, vice president of meteorology and climate change at Skymet Weather.
“The WD forming on January 20 will be the last active WD of the month. After that too, there are predictions of WDs but they are likely to bring precipitation only over the Western Himalayan region and places like Jammu and Kashmir and Ladakh,” he said.
The excess rain received during January will actually be good for the Rabi crops that are grown during winters.
“Usually rain is good for Rabi crops unless it is during the time when the crops are in a nascent stage and can be washed away. The rain was also not torrential that could lead to flooding and destruction of crops. The rain received during January will only increase the soil moisture, except for isolated places where hail must have done some damage,” said Palawat.