今年10月，我国已经进入拉尼娜状态

Group 1: La Niña Phenomenon - The La Niña phenomenon refers to the significant and sustained cooling of sea surface temperatures in the eastern and central equatorial Pacific Ocean, with China entering a La Niña state in October this year [1] - La Niña state does not equate to a La Niña event; a La Niña event is defined by the NINO 3.4 index remaining below -0.5 degrees Celsius for five consecutive months [2] - The probability of a double La Niña event occurring this winter is low, despite the ongoing La Niña state having some impact on China's climate [2] Group 2: Impact on Weather Patterns - La Niña directly influences weather by generating a cyclonic circulation anomaly over the Northwest Pacific and South China Sea, leading to prevailing northeast winds that suppress moisture transport to eastern and southern China, potentially causing drought conditions [4] - The expected winter conditions in regions like East and South China may lead to prolonged dry spells, particularly in the winter-spring period [4] Group 3: Freezing Rain and Its Effects - Freezing rain is a hazardous winter weather phenomenon where liquid rain freezes upon contact with surfaces below 0 degrees Celsius, posing risks to transportation, power supply, and daily life [5] - The formation of freezing rain requires two key conditions: sufficiently low temperatures (between -8 to 0 degrees Celsius near the ground) and the presence of precipitation [7] - Freezing rain can lead to the formation of ice layers on power lines and trees, increasing the risk of power outages and damage to vegetation [10] Group 4: Regional Analysis of Freezing Rain - Guizhou province experiences the highest frequency of freezing rain in China, with the winter months from December to February being the peak period for such weather [13] - This winter, the probability of widespread freezing rain in Guizhou is expected to be lower than usual, with average temperatures projected at 7.1 degrees Celsius [15] - The distribution of freezing rain in Guizhou shows a pattern where western regions experience more occurrences due to higher altitudes and stable weather systems [16][18]