China has issued a heavy snow warning in Shanghai and surrounding regions for Thursday and Friday, advising against unnecessary outdoor activity, Bloomberg reported. The National Meteorological Center of China said Shanghai may get heavy snow – defined as snowfall of 5-9 millimeters in a 24-hour period – starting 8 a.m. on Thursday. Ice and snow removal operations delayed nearly 100 international and domestic flights at Shanghai’s Pudong and Hongqiao airports. Hangzhou in neighboring Zhejiang province canceled all departing flights from 1-7 p.m. Meanwhile, blizzard warnings were issued in Jiangxi, Anhui and Zhejiang provinces. The advisories are given if snowfall exceeds 10 millimeters in a 24-hour period. Officials have said rain, snow and ice could upset travel plans for millions who need to commute during the Lunar New Year holiday early next month.