Under the influence of cyclonic circulation, low pressure area formed over Bay of Bengal (BoB). It has intensified to a well marked low pressure area over northwest and adjoining north BoB. Cyclonic circulation is extending up to high tropospheric levels in the atmosphere, tilting southwest with height. The system may strengthen further, a notch higher to become depression for short duration.
The well marked low pressure is centered around 19°N and 90°E, almost east abeam Puri by over 400km. It is likely to become a weak depression over next 12hr and also move northwest, little closer to the coast. Most of the weather activity today will remain confined to the sea and Bangladesh. In the next 24hr, the system will move inland and widespread heavy rain and thundershowers are likely over West Bengal, North Odisha, Jharkhand, Bihar and adjoining parts. Intense weather activity is expected for nearly 48hours over the region.
The low pressure is unlikely to move deep and will stay put over the eastern parts, gradually shifting closer to the foothills of Bihar and East Uttar Pradesh. After 3rdAugust, the weather system will weaken as a cyclonic circulation and have tendency to merge with the monsoon trough. The entire stretch of monsoon trough will shift close to the foothills on 4thAugust and remain north of its normal position for the subsequent one week or may be longer.
Active to vigorous monsoon conditions are likely over West Bengal, North Odisha, Bihar, Jharkhand, East Uttar Pradesh, North Chhattisgarh and adjoining East Madhya Pradesh between 01st and 05th August, albeit in a staggered manner. While, the rainfall will increase all along the Indo Gangetic plains from Punjab Haryana, Delhi, Uttar Pradesh, Bihar and Sub Himalayan West Bengal, most of the western, central and southern parts will experience mild monsoon activity. Such conditions will prevail till a fresh monsoon system emerges in the Bay Of Bengal, to pull the monsoon trough back to normal position. However, there is no likelihood of any fresh monsoon low forming during 1st half of August. Overall, monsoon may enter in to a week phase reducing the rainfall activity, largely over western, central and southern parts of the country.
