Although it is only October, a heavy snowfall that is rare in the same period is about to begin.
To talk about this snow, we have to start with the super strong storm thousands of miles away. The extremely strong cyclonic storm "Arnab" in the Bay of Bengal made landfall on the coast of India on the morning of the 28th. At present, "Arnab" has weakened from a strong cyclonic storm to a cyclonic storm (equivalent to my country's tropical storm level) and continues to move northward, gradually approaching the Himalayas.
Affected by the residual vortex circulation and high-altitude trough after the weakened cyclone storm, coupled with the topographic uplift of the Himalayas, there will be an obvious rain and snow weather process in the Tibetan Plateau of my country.
Specifically, from the night of the 29th to the 31st, there were heavy to heavy rains in the lowlands of the valleys near the Himalayas in southern Tibet, blizzards to heavy blizzards in high-altitude areas, and extremely heavy snowstorms in local areas (accumulated snowfall can reach 30 to 60 mm). The local precipitation in southern Tibet is quite extreme, and we need to be alert to the risk of disaster caused by heavy snowfalls.
The cumulative precipitation in most of the above-mentioned areas is 2 to 8 millimeters, 20 to 40 millimeters in the area along the Himalayas, and 50 to 110 millimeters in local areas; the maximum cumulative snowfall can reach 30 to 60 millimeters. The precipitation phase at the southern edge of the plateau is relatively complex. There will be 10 to 30 centimeters of additional snow in southern Tibet, which may reach more than 40 centimeters locally.
Among them, the southern edge of Tibet was mainly affected from the 29th to the 30th, and extended to the central plateau from the 30th to the 31st. The 30th was the period with the strongest rain and snow. There were heavy snowstorms or sleet in parts of northern, southwestern and southern Tibet. There were local heavy snowstorms or extremely heavy snowstorms (30~50 mm) in the south. The southern part of Shigatse was the core area of heavy snowfall, and the intensity of snowfall was rare during the same period.
The snowfall weakened significantly on the 31st, with light to moderate snow or sleet in central and southern Tibet.
Li Ning, a meteorological analyst at China Weather Network, said that from a year-round perspective, May-June and October-December are the active periods for cyclonic storms in the Bay of Bengal. If you encounter a cyclonic storm that moves north after landing, there may be heavy rainfall in the piedmont areas of the Himalayas. Under the combined influence of high-altitude troughs, it may also cause strong rain and snow weather on the Qinghai-Tibet Plateau in my country.
In May 2020, affected by the snowfall brought by the extremely strong cyclone storm "Amphan" in the Bay of Bengal, my country's Mount Everest elevation measurement mountaineering team was once unable to continue climbing and could only retreat to 6,500 meters.
Therefore, it is not unusual for snowfall to occur in Tibet in October, but this time the water vapor conditions were very good, and the intensity of the snowfall was rare for the same period. Today, the Ministry of Agriculture and Rural Affairs and the China Meteorological Administration have jointly issued a snow disaster risk warning for the agriculture and animal husbandry industry, reminding that the risk of snow disasters for agriculture and animal husbandry in Yadong County, Nyalam County, Gyirong County, Shigatse City, and western Zada County, Ngari Prefecture is high and requires vigilance.
In addition to heavy snowfall in Tibet, due to the influence of cold air from the east, there will also be widespread rainfall from the eastern part of Northwest China, the eastern part of Southwest China to southern North China, Huanghuai, Jianghuai and other places from October 31st to November 1st.
Among them, the line from southern Shanxi and northern Chongqing to Huanghuai is the area where heavy rainfall is concentrated. On the 31st, there will be moderate to heavy rains in the above-mentioned areas, local heavy rains, and the rainfall intensity is also rare in the same period; starting from November 1st, cold air will push the rain belt to weaken the southward pressure.
Looking forward to the later period, in early November, there will be continuous rainy weather from the eastern part of Southwest China to Jiangnan, and the precipitation will be higher than the same period in normal years, so we need to pay attention.
