On April 25, 1989, a 1000 mbar (hPa; 29.53 inHg) area of low pressure propagated over Bihar and West Bengal, India, with a trough extending east across Bangladesh and into Manipur, India. The system remained largely stationary throughout the day into April 26. On that day, another low approached from Madhya Pradesh, and in conjunction with a ridge over China, the pressure gradient became tighter across Bangladesh. Warm, moist air flowed northeast from the Bay of Bengal while cool, dry air flowed south from the Himalayas. In the upper-levels of the atmosphere above the low, strong westerly winds from the jet stream created ample wind shear, a key factor in the development of supercell thunderstorms of producing tornadoes. The jet stream became particularly intense on April 26, with a sounding from Dhaka observing winds at a height of . An established dry line over western Bangladesh served as a focal point for thunderstorm development. By 12:00 UTC, all the aforementioned factors served to produce severe thunderstorms across the country.