云南滇东及滇东北地区是云南省的重冰区。本文利用电网传感器和人工观测覆冰资料、欧洲中心再分析资料（ERA5）等，针对 2023年 12月云南昭通地区持续一周的覆冰天气进行了诊断分析。结果表明：该过程覆冰区主要位于高原北部迎风坡处，观测覆冰厚度高值点对应地形高度1500~2000 m。过程覆冰类型复杂多样，不同类型与冷空气影响时段相对应。其中，高温高湿型（GG 型，气温>0 ℃，湿度≥75%）出现在冷空气影响的初始阶段；当冷暖空气对峙，静止锋维持时，低温高湿型（DG 型，气温≤0 ℃，湿度≥75%）覆冰大范围发生，该类型出现频次最多；冷空气影响趋于结束时，覆冰类型以低温低湿型（DD型，气温≤0 ℃，湿度<75%）为主；高温低湿型（GD型，气温>0 ℃，湿度<75%）出现频次最少。覆冰形成期，区域上空500 hPa为西风气流或有短波槽影响，700 hPa为西南风或西南急流，为降水提供了充沛的水汽。700 hPa 有时形成切变线，配合地面静止锋，为覆冰降水提供了良好的动力抬升条件。GG型和DG型覆冰发生时，水汽条件充沛，上升运动强，覆冰是与冻雨（毛毛雨）、雨夹雪或小雪及雾相关的混合结冰。DD型和GD型发生在冷空气影响的末期，湿度和动力条件均较差。DD型覆冰可能与夜间辐射降温作用下形成的冻雾及雾中毛毛雨有关，而GD型覆冰的形成可能更多的是与局地下垫面热力或微地形抬升引起的雾或弱降水有关。

The eastern and northeastern regions of Yunnan province are severe ice-coating areas. This study con‐ ducts a diagnostic analysis of a one-week ice-coating event in Zhaotong of Yunnan province during December 2023，utilizing manual observations，power grid sensor data，and ERA5 reanalysis data. The results indicate that the ice-coating area is predominantly located on the northern windward slope of the plateau，with the maximum ice thickness observed at elevations between 1500 and 2000 meters. The types of ice-coating are complex and var‐ ied，closely related to the timing of cold air influence. Specifically，the high-temperature and high-humidity type （GG type，t>0 ℃，RH≥75%）occurs during the initial stage of cold air influence. When the cold and warm air masses confront each other and a stationary front is maintained，the low-temperature and high-humidity type （DG type，t≤0 ℃，RH≥75%）occurs most frequently. As the cold air influence near its end，the low-temperature and low-humidity type（DD type，t≤0 ℃，RH<75%）becomes dominated. The high-temperature and low-humid‐ ity type（GD type，t>0 ℃，RH<75%）is the least frequent. During the ice formation period，the 500 hPa level is characterized by westerly airflow or short-wave troughs. At the 700 hPa level，southwesterly winds are ob‐ served，occasionally reaching the intensity of southwesterly jets，which transport abundant moisture. At 700 hPa，a wind shear line sometimes forms，coinciding with the surface stationary front，providing favorable dy‐ namic uplift conditions for precipitation during icing events. The GG and DG types of icing occur under condi‐ tions of abundant moisture and strong uplift. Both of them are mixed icing associated with freezing rain（driz‐ zle），sleet，snow or fog. In contrast，the DD and GD types occur during the late stage of cold air retreat，charac‐ terized by weaker humidity and dynamic conditions. The DD type may be associated with freezing fog and driz‐ zle under the influence of surface radiative cooling at night. In contrast，the formation of GD type is more likely related to fog or weak precipitation induced by local surface thermal or micro-terrain uplift.