Very high rainfall was recorded over northwest India and parts of central and peninsular India in the first five days of 2020 — unusual for this time of the year, according to the weather department.
Overall, India recorded 274% excess rain till January 6 with 17 states recording “large excess”, or 60% above normal rain. There was no rain in 14 states during the week.
India Meteorological Department (IMD) scientists said such widespread and heavy rains in January was being recorded for the first time in several decades.
Usually, India sees an average rainfall of 2.4 mm from January 1-6. This time, it was 9 mm.
“Last year, we saw 27.4 mm rain in the entire country in January, while the normal is 16.1 mm. This year, we have already realised 9 mm. This spell was unique because it may be one of the longest wet spells recorded in January,” said RK Jenamani, senior scientist, national weather forecasting centre.
While winter rain occurs over northwest India during January-February due to western disturbances (WDs), the intensity of the one that triggered rainfall in northwest India in the first week of 2020 was very high.
In peninsular India, the northeast monsoon hasn’t withdrawn completely and intense easterly waves are bringing widespread and heavy rains.
“The intensity, distribution and lingering rains for a number of days was striking this time. There is always winter rain; we expect six western disturbances on average in January and February, but they are not usually as intense as this one. The WD moved very slowly, bringing rain and snow continuously from January 3,” said Kuldeep Shrivastava, head, regional weather forecasting centre.
The western disturbance has moved away and the moisture feed from Arabian Sea has significantly reduced, according to IMD’s Wednesday bulletin.
A feeble western disturbance, however, is likely to impact only the Western Himalayan region on Thursday and Friday, bringing light rain and snow in the hills.
Minimum temperatures are likely to fall again by 4-6 degrees Celsius over plains of northwest India during the next 4-5 days.
Cold wave conditions are likely over plains from January 11 to 13.
Due to abundant moisture and other favourable meteorological features, dense to very dense fog is likely in many pockets over northwest India between January 7 and 10.