Weather patterns across India are undergoing notable shifts as multiple atmospheric developments unfold simultaneously across the subcontinent. While northern plains covering Delhi-NCR, Haryana, Punjab, and western Uttar Pradesh have experienced a slight softening of daytime temperatures, oceanic disturbances are gaining substantial momentum. The country faces two major meteorological concerns: the overarching threat posed by an intensifying El Nino pattern in the Pacific Ocean, and the imminent impact of an intensifying low pressure area over the Bay of Bengal. Should this developing system intensify further from a deep depression into a full-fledged tropical cyclone, it could bring coastal regions under the grip of a storm named Arnab, a nomenclature suggested by Bangladesh. While meteorological experts maintain that confirming cyclone formation at this stage is premature, the India Meteorological Department has issued strong alerts predicting wind speeds reaching up to 75 kmph and torrential rainfall across multiple eastern and central states.
Trajectory and Timeline of the Bay of Bengal Weather System
According to official meteorological observations, an upper-air cyclonic circulation persisted over the north Andaman Sea and its adjoining territory at middle tropospheric levels at 0830 hours IST on September 19. Under its direct influence, a well-defined low pressure area formed by 1730 hours IST on the same evening. By 0830 hours IST on September 20, this weather system was centered over the east-central Bay of Bengal and the contiguous north Andaman Sea. Forecast models indicate that the system is tracking west-northwestwards while undergoing progressive strengthening.
Meteorologists expect the system to intensify into a depression by September 21, subsequently consolidating into a deep depression over west-central Bay of Bengal by September 22. Continuing along its west-northwest trajectory, the center of the weather system is expected to arrive near the coasts of north Andhra Pradesh and south Odisha, positioning itself over west-central and adjoining northwest Bay of Bengal by the morning of September 23. This dynamic sequence is projected to sustain widespread rainfall activity across central and southern parts of the country for five to six consecutive days.
Heavy Rainfall and Gale-Force Winds for Coastal Odisha and Andhra Pradesh
Coastal belts along eastern India are slated to experience the brunt of this incoming system. The meteorological department has highlighted south Odisha and north coastal Andhra Pradesh as zones requiring heightened vigilance, predicting isolated extremely heavy downpours alongside widespread heavy to very heavy rainfall on September 23 and 24. North coastal Andhra Pradesh will witness elevated precipitation from September 22 through September 24, while south Odisha faces persistent heavy rain spells between September 22 and September 25.
Maritime and coastal safety remain paramount as gusty conditions escalate. Coastal tracts of Odisha are anticipated to encounter wind speeds ranging between 50 and 60 kmph, accompanied by gusts touching 70 kmph on September 23 and 24. Similarly, nearshore waters and coastal districts of south Odisha and north Andhra Pradesh may witness sustained wind speeds of 55 to 65 kmph on September 23. Gale-force winds are also forecast to sweep across coastal stretches of south Andhra Pradesh and West Bengal throughout September 23 and 24, prompting safety warnings for coastal communities and fishermen.
Severe Downpours Forecast for Chhattisgarh, Telangana, and Central Belts
The impact of this weather system will extend deeply into the hinterlands of central India. In Chhattisgarh, widespread rain and thunderstorm activity are anticipated to linger until September 26. Very heavy downpours are forecast across the state between September 23 and September 25, with south Chhattisgarh likely receiving isolated extremely heavy rainfall on September 24. Telangana is similarly primed for extensive rainfall coverage from September 21 to September 26, culminating in severe rain spells from September 23 to September 25 accompanied by squally winds of 50 to 60 kmph and gust peaks reaching 70 kmph.
Neighbouring Vidarbha is slated to receive widespread rain between September 21 and September 26, with intense precipitation concentrated on September 24 and September 25. Eastern districts of Madhya Pradesh are forecast to see broad weather activity between September 23 and September 26, including very heavy showers in isolated spots on September 25 and 26. These developments follow active rain spells observed in the 24 hours leading up to 0830 hours IST on September 20 across parts of Telangana, Rayalaseema, and Tamil Nadu.
Pacific El Nino Threat and Broader Climate Implications
Looming behind this immediate cyclonic disturbance is the broader, macro-climatic disruption generated by the Pacific Ocean. Scientists have previously issued warnings regarding historically strong El Nino conditions across the equatorial Pacific. This abnormal warming of sea surface temperatures has historically disrupted Indian monsoon currents, sharply raising the probability of prolonged dry spells, agricultural distress, and drought-like conditions across vulnerable agrarian belts. India thus confronts a dual climate dilemma: the acute, short-term threat of intense flooding downpours and 75 kmph winds triggered by the Bay of Bengal low pressure system, juxtaposed against the strategic, systemic moisture deficit heralded by El Nino.
