Monthly Summary Data November 2023

In November 2023, high-pressure-area from China mainly extended its ridge to cover upper northern, upper northeastern and the South China Sea in the first half of the month resulting in an overall mild winter in Thailand with cool weather in some areas of the northern and northeastern parts. In the second half of the month, high-pressure area periodically extended to cover upper Thailand. As a result, the temperature obviously decreased nationwide with generally cool weather in the northern and northeastern parts, with cold weather in some areas in the upper portion and cool weather was found in the central and eastern parts as well. However, the average monthly temperature of this month was anomalous warmth in all parts in particular across the northern and northeastern part where experienced 1.1-1.4^oC above normal. For rainfall, due to the prevailing of the easterly wind over Thailand, the Gulf of Thailand and the Andaman Sea coupled with the easterly wave moving through lower central, eastern part, The Gulf of Thailand and the southern parts in the beginning of the period causing unusual rainfall in upper Thailand during that time. The southern part was further influenced by the northeast monsoon that prevailed over the Gulf of Thailand and the southern part in the second half of the month, the active low-pressure cell moving to cover the lower southern part during the November 25-27 and a low-pressure cell covering the east side of Peninsula Malaysia on November 29-30. These brought plentiful rainfall in southern part almost month especially along the east coast that experienced heavy to very heavy rainfall in many areas in the middle and the end of the month with flooding in some places. Monthly rainfall was above normal in central 18.6 mm (59%), eastern 6.7 mm (14%), southern part (east coast) 108.5 mm (32%) and southern part (west coast) 10.9 mm (6%). %) whereas that of below normal in northern part 16.2 mm (60%) and northeastern part 3.3 mm (18%). The average total rainfall over Thailand in November was 17% above normal. Overall, the average temperature in Thailand was 0.9°C higher than normal. More details were as follow.