Rainy Spell For Northeast India, Heavy Rains At Some Places

Northeast India has remained well short of winter rainfall, this season. The worst was the month of January, like other parts of the country, with minimal rains. Conditions are only marginally better now. Shortfall still persists in the range of 50-70%, for the season. The worst hits were Meghalaya, Assam, Mizoram, Manipur and Tripura. Arunachal and Nagaland, a shade better. Rains are likely to lash the region shortly, albeit for 2-3 days only.

The western disturbances by itself, does not effectively reach northeast India. From the Western Himalayas to the Northeast Frontier region, the weather systems get distorted and deformed due to terrain. Limited rains are received over the valley and the mountains, as well. These weak weather systems need to be reinforced with moisture from the Bay of Bengal, for any decent activity.

Occasionally, the seasonal anticyclone over the central parts and the eastern coastline gets displaced over the northwest Bay of Bengal. This becomes ideal for pumping moisture over the northeastern parts.  Such a situation, coupled with the remnant of western disturbance, if any, over Assam and Arunachal, can lead to winter rains with a decent spread across all parts. Even, Bangladesh also receive a fair amount of winter weather under such conditions.

An active western disturbance has lashed northern mountains with heavy snowfall over the last 2 days. The weather system, a weakened one now, is vacating and moving eastward. Give a lag of about 48 hours and with other conditions favourable, northeast India will come in for a wet spell. Anticyclone over the northwest Bay of Bengal is placed ideally to fuel moisture-laden southwesterly winds over the region. Under the combined influence of the western disturbance and anticyclone, fairly widespread rain and thundershowers are likely over most states.

The weather activity will commence from 21^st Feb and last for 3 days, till 23^rd Feb. The remnant effect will be seen on 24^th Feb as well. Peak intensity and spread are anticipated on 22^nd Feb. A Few places over Assam & Meghalaya and Arunachal Pradesh will receive moderate to heavy showers. Most of the weather activity will happen in the night and early morning hours. Broad clearance can be expected from 25^th Feb onward.