Northeast India comprises of three sub-divisions: a) Arunachal Pradesh, b) Assam and Meghalaya and c) Nagaland, Manipur, Mizoram and Tripura (NMMT).
During the post Southwest Monsoon season i.e. during the months of October, November and December large variability in terms of rainfall activity is observed over these northeastern states. Sharp decline in rains is witnessed over all the sub-divisions starting from October to December.
The main reason for the decline of rains is because the Southwest Monsoon season continue to prevail over Northeast India at least till mid-October and frequently even extending up to October 20. However, due to the same reason rains in October are very high over the region.
Further during the months of November and December, all the northeastern states experience mild winters. The weather systems are not very active during this time; thus, rains are less, and mild winters are observed.
Moreover, we see a contrast during the month of October and November. Both months are compensatory to each other in terms of rainfall activity. Lets us have a look at the rains observed during the months of October and November in 2016 and 2017:
However, this time this prediction has not been proved right as rains have been highly deficient over all the regions of Northeast India during both the months. Have a look at the rainfall activity over all the northeastern states in October and November:
Now further also in December, the average rains are already less and along with that rains tend of decline even more. Thus, as a result the rain deficiency increases more and no improvement in rain deficiency is expected.
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