New Delhi, Jan. 7 -- Delhi is likely to be in the grip of severe chill over the next few days, with the India Meteorological Department issuing a yellow alert until Thursday, predicting dense to very dense fog and chances of "cold day" conditions. A combination of upper-level fog and icy-cold northwesterly winds left the city shivering on Tuesday. According to the IMD, "cold day" conditions were recorded in isolated pockets, with fog restricting visibility to 250 metres. Persistent shallow fog and haze meant many parts did not see sunshine. The IMD classifies a "cold day" when the minimum temperature is below 10degC and the maximum is 4.5degC or more below normal; it is a "severe cold day" when the departure is 6.5degC or more. On Tuesday, ...