During the week, all the Sub-Divisions of India received largely deficient / no rainfall except for the Andaman & Nicobar Islands, which received excess rainfall. Scattered rainfall with isolated heavy rainfall occurred only on 10th January. Scattered rainfall occurred over Andaman & Nicobar Islands on some days and over Lakshadweep on one / two days of the week; isolated light rainfall occurred over Arunachal Pradesh, Assam & Meghalaya and Kerala on one / two days of the week. Under the influence of trough of low at mean sea level from Equatorial Indian Ocean to Comorin area rainfall occurred at a few places with heavy rainfall at isolated places over Tamil Nadu & Puducherry and between 0830 hours IST of 10th January and 0830 hours IST of 11th January 2018. Northeast monsoon rainfall has ceased over Tamil Nadu & Puducherry, Kerala and adjoining parts of Andhra Pradesh and Karnataka on 15th January 2018. Fog and Cold Wave FOG During the week, Very dense to dense fog was observed at many places over Uttar Pradesh; Assam & Meghalaya, Tripura, Bihar, at isolated places over Sub-Himalayan West Bengal, and Punjab on many days of the week. Dense fog was observed at isolated places over Uttrarakhand, Odisha, Haryana on a few days and over Coastal Andhra Pradesh, Gangetic West Bengal and Rajasthan on one / two days of the week. Cold wave / Severe cold wave conditions prevailed at a few places over Interior Odisha, Haryana, Punjab, Uttar Pradesh and Bihar on a few days of the week; at isolated places over North Rajasthan, Himachal Pradesh, Jammu & Kashmir, west Bengal and Jharkhand on one / two days of the week.. The lowest minimum temperature 0.0°C was recorded at SIKAR (East Rajasthan) in the plains of the country on 16th January. Cold day / Severe cold day conditions prevailed at many places over East Uttar Pradesh, Bihar; at a few places in West Bengal on most days of the week and at isolated places over Haryana, Punjab, north Madhya Pradesh, Uttarakhand, West Uttar Pradesh, on one / two days of the week. The lowest maximum temperature of 10.2°C was recorded at Najibabad & Bahraich on 11th and over Shahjahanpur (Uttar Pradesh) on 12th. A fresh Western Disturbance as a cyclonic circulation was located over East Afghanistan & adjoining Pakistan. It will move northeastwards due to this system and temperature will fall by 2-3oC after 2-3 days and fog and Cold wave conditions may occur during the subsequent two days thereafter. An induced cyclonic circulation was located over Punjab and neighbouring areas. Fig: The cyclonic circulation was located over the Malay Peninsula & adjoining south Andaman Sea.
The cumulative rainfall Sub-Division wise for the week (11-17 January 2018) predicted by IMD GFS model shows that Andaman & Nicobar Islands, Konkan & Goa, Tamil Nadu & Puducherry, Kerala and Lakshadweep would receive excess rainfall, whereas only Andaman & Nicobar Islands received excess rainfall. Other Sub-Divisions received Deficient / Largely Deficient or no rainfall, Saurashtra & Kutch, Konkan & Goa, North Interior Karnataka would receive normal rainfall, South Interior Karnataka would receive Deficient rainfall and Rayalaseema would receive largely deficient rainfall but in fact they have not received any rainfall. The predictions which were right for the Sub-divisions other than Andaman & Nicobar Islands are Arunachal Pradesh, Assam & Meghalaya, which received rainfall as predicted. Overall Model has predicted well for 28 out of 36 Sub-Divisions of the country.
During the week, rainfall over the country as a whole was 96 per cent below the long period average (LPA). Only Andaman & Nicobar Islands received excess rainfall, Tamil Nadu & Puducherry received Deficient Rainfall and other four Sub-Divisions which received Largely Deficient rainfall are Arunachal Pradesh, Assam & Meghalaya, Kerala & Lakshadweep. Central India & Northwest India have not received any rainfall. Details of the rainfall distribution over the four broad homogeneous regions of India are given below:
For the country as a whole, cumulative rainfall was (-88 per cent) of LPA as on 17th January 2018.Cumulative rainfall was deficient over the Southern Peninsula and Northeast India. Rainfall was excess over Andaman & Nicobar Islands; normal over Nagaland, Manipur, Mizoram & Tripura; deficient over Assam & Meghalaya & Tamil Nadu & Puducherry. The other Sub-divisions received largely deficient / no rainfall over the rest of the Sub-divisions of the country. Details of the rainfall distribution over the four broad homogeneous regions of India are given below:
Rainfall activity will be normal over Andaman & Nicobar Islands and below normal over Western Himalayan Region and near normal over plains of Northwest India. Overall activity over the country will be below normal.
Below normal rainfall activity is likely over Western Himalayan region and above normal rainfall activity over extreme south Peninsula and near normal over Andaman & Nicobar Islands. Overall activity over the country will be below normal.