Initially moderate upper-level wind shear inhibited organization, while strong diffluence aloft aided in developing convection.

[8] Vertical shear decreased greatly as the circulation became better defined, and a Tropical Cyclone Formation Alert was issued on November 11 while located a short distance south of the Andaman Islands.

[20] As it intensified to a Category 4-equivalent cyclone on November 15,[2] thousands of emergency officials were put on standby in eastern India and Bangladesh in advance of the storm's arrival.

Forecast heights of the storm surge predicted by a numerical model developed by Dr. Hassan Mashriqui (Louisiana State University) was communicated to the emergency response authorities in Bangladesh,[21] prompting a massive evacuation of low-lying coastal areas.

[26] Storm surges reaching up to a height of 3 metres (9.8 ft) were reported in the coastal areas of north Chennai in southern state of Tamil Nadu in India, triggering panic among the fishing community.

[31] Much of the capital city of Dhaka was also severely affected, as electricity and water service were cut and significant damage was reported there due to winds and flooding.

[5] Cyclone Sidr slammed the highly vulnerable low lying densely populated coastal areas of Bangladesh with heavy rain, winds of up to 190 km/h (120 mph), and a storm surge.

Effective early warning, cyclone shelters and disaster relief measure implementations helped reduce the death toll.

Since 1991, the donor community, including the US and EC, has supported disaster-preparedness to mitigate the impact of tropical storms and improve post-disaster relief and reconstruction.

Disaster shelters on stilts housing refugees plus early warning systems and timely evacuations appear to have greatly reduced the fatalities from Sidr.

[43] The Ministry of Food and Disaster Management allocated 4,000 metric tonnes of rice, 7,500 tents, 18,000 blankets, and 30 million Taka (US$435,569) in relief grants.

People of the cyclone affected area experienced severe health problems such as diseases like diarrhea, which spread due to shortage of drinking water.

[46] By January 15, 2008, the World Health Organization (WHO) reported that 44 people had Jaundice, 3,572 had Diarrhoea, 3,210 had Pneumonia, 7,538 were suffering from a skin disease, 2,309 had eye infections, and 10,349 had Typhoid Fever.

To help reduce further spreading of the diseases, the Government of Norway provided the WHO with four water treatment plants to be used in areas affected by Sidr.