In the last 24 hours, from 8.30 am on Tuesday to 8.30 am on Wednesday, Baghmara and Sohra (Cherrapunji) in Meghalaya received extremely heavy rain measuring 28 cm and 23 cm respectively. Mawsynram in Meghalaya, too, experienced incessant rainfall measuring 23 cm during the period. In Assam, Beki-Mathanguri station received extremely heavy rain measuring 23 cm.
All three met-subdivisions in the northeast are facing deficit rainfall this monsoon, which set in on June 1. Met officials said more rainfall is crucial to bring down the deficit. While the shortfall in Arunachal Pradesh, as of Wednesday, has been 23%, the Assam-Meghalaya subdivision is facing a deficit rainfall of 8%, though in normal range. The subdivision which encompasses Nagaland, Manipur, Mizoram and Tripura is facing the highest rainfall deficit at 39%.
“A trough at mean sea level runs from northeast Uttar Pradesh to northeast Assam across Bihar and the sub-Himalayan West Bengal. Moisture incursion from the Bay of Bengal to the northeast is also taking place in the last couple of days due to strong southwesterly winds in the lower levels of the atmosphere, “said Sunit Das, a senior scientist at the Regional Meteorological Centre, IMD. Under these weather conditions, he said, light to moderate rain in many to most palaces in the northeast is very likely in the next four to five days.
The IMD has issued a ‘red alert’, predicting extremely heavy rainfall at isolated places in South West Khasi Hills district of Meghalaya on Thursday. Red alert is a warning for the disaster management agencies to take action to meet any possible eventuality due to rains. Heavy to very heavy rainfall is also very likely over the Chirang district of Assam and the West Garo Hills in Meghalaya on Thursday.
An ‘orange warning’, asking the administration to be prepared, has been issued for the East Khasi Hills district of Meghalaya. Here extremely heavy rainfall is likely at isolated places on Thursday.
West Assam may experience heavy to very heavy rainfall over South Salmara, Kokrajhar, Baksa, Barpeta and Dhemaji districts of upper Assam on Thursday. East, South and South West Garo Hills, East Jaintia Hills, East Khasi Hills districts of Meghalaya, along with Upper, East and Lower Siang, Lower Dibang Valley, Dibang Valley and Lohit districts of Arunachal Pradesh have also been warned over heavy to very heavy rain. Lawngtlai district of Mizoram, Gomati, Sipahijala, South Tripura and West Tripura districts have also been put under ‘orange warning’ for the next 24 hours. The intensity of rain may reduce slowly from Friday, though heavy rain may continue to lash parts of Assam and Meghalaya till July 4, IMD said.
As per the long-range forecast by IMD, seasonal rainfall in the northeast is most likely to be below normal this monsoon (between June and September) with less than 95% of the long period average (LPA). In its long range forecast for the southwest monsoon, the Met office, however, predicted that rainfall over the country as a whole is most likely to be normal, ranging from 96% to 104% of LPA.