The latest seasonal forecast was released by the ANSO-MISSPAD project in Aug 2020, which combined the predictions of FGOALS-f2, CMME and TMDCFS. It predicts more convective precipitation near the Maritime Continent (the islands of Indonesia, the Philippines and southern parts of Southeast Asia) this autumn in the developing phase of a weak La Ni？a event and a negative phase of Indian Ocean Dipole. The precipitation will increase over the northern Thailand and decrease over the southern Thailand which could lead to a drought autumn. The temperature in most Southeast Asia in September-November 2020 will be higher than average, in Indo-China Peninsula, the temperature anomaly is more than 0.5-1℃ higher, possibly leading to more frequent and stronger hot events. While Indonesia will suffer from unusually heavy precipitation, probably following a flooding disaster in some areas.
More rainfall is predicted near the Maritime Continent, increasing the risk of floods and relevant geological disasters.
According to the recent predictions, released by the IAP FGOALS-f2_v1.3 of IAP/CAS and the China Multi-Model Ensemble (CMME) of the China Meteorological Administration in August 2020, there is more rainfall in the Maritime Continent in Southeast Asia, with the anomaly center around Indonesia, especially in the adjacent ocean regions where the precipitation anomalies can exceed 100%. The precipitation changes in the Indo-China Peninsula are small, and the possibility of persistent heavy rainfall is low. The positive precipitation anomaly mainly locates over the Northeast part of Thailand. Meanwhile, the precipitation may decrease over south Thailand and leads to a drought Autumn that influences the local development of agriculture.
Figure 1. Precipitation anomaly percentage (%) predicted by ANSO MISSPAD for the boreal Autumn (September-October-November) of 2020: （a）FGOALS-f2, (b)CMME, (c) TMDCFS.
A warmer autumn is predicted over all the Southeast Asian land regions.
According to the latest predictions, the surface air temperature anomaly is about 0.5 ℃ higher than usual in most Southeast Asia. The average temperature on the west coast of Indonesia, South China Sea, and the western Philippines is predicted to be 1.0 ℃ higher than usual. In September, the higher temperature zone will be mainly in southeastern Myanmar, southern Thailand, and the south coast of Laos, and Vietnam. While in October and November, the higher temperature zone will be mainly in northern Myanmar.
Figure 2. The temperature anomaly (℃) predicted by the FGOALS-f2 Subseasonal-to-Seasonal Prediction System of ANSO MISSPAD for the Autumn(September, October and November) of 2020.
The FGOALS-f2 weather-climate dynamic ensemble forecast display platform
Bian He and Jinxiao Li, Institute of Atmospheric Physics, Chinese Academy of Sciences
Jun Jian, Dalian Maritime University