Newsletter Issue 59 (September 2025)

HKMetSoc Talk Series 2025 – Why Carbon Neutrality Matters? How?

Date/Time: 25 October 2025, 14:30 – 16:30
Venue: Social Sciences Chamber, 11/F, The Jockey Club Tower, HKU
Application via https://forms.gle/5jMTopsKKFPdVpFJ8
The event will begin with a 1-hour lecture ‘Why Carbon Neutrality Matters? How?’, followed by a workshop ‘DIY microclimate instrument for geography fieldwork’.

The Weather of August 2025 – An August with outbreaks of heavy rain

Mainly attributing to the heavy rain associated with an active southwest monsoon and upper-air disturbances in early August, and a number of tropical cyclones in mid-August, the month was much wetter than usual. The monthly rainfall recorded at the Hong Kong Observatory was 939.2 millimetres, more than double the August normal of 453.2 millimetres, and the third highest on record for August.

Global Seasonal Climate Update for Oct-Nov-Dec 2025

For Oct–Nov-Dec 2025, SST anomalies in the Niño 3.4 and Niño 3 regions are forecast to decline, with the potential emergence of a weak La Niña. Continued above-average SSTs in the western Pacific are expected to sustain a strong east–west SST gradient, reinforcing La Niña-like conditions across the equatorial Pacific. The IOD index is projected to shift into a negative phase. In the equatorial Atlantic, SSTs in the northern tropical region are forecast to remain slightly above average, while the southern tropical Atlantic is expected to stay near average.

WMO Ozone and UV Bulletin No. 3 released

– Ozone layer remains on track to recovery in coming decades
– WMO Ozone Bulletin says ozone hole in 2024 smaller than previous years
– Vienna Convention and Montreal Protocol show benefits of science for global action
– Stratospheric ozone protects people’s and planetary health
– Continued atmospheric monitoring is vital (Full report)

NOAA and partners deploy mini ocean robots to collect hurricane data

NOAA, in partnership with The University of Southern Mississippi and with the robotics company Oshen, launched five small uncrewed surface vehicles called C-Stars in the waters off the U.S. Virgin Islands on August 31 to collect critical data to better understand hurricane development and activity. The deployment is the latest effort by NOAA to advance data collection to improve hurricane research and forecasting.

Machine Learning model demonstrates promising seasonal forecasting capability

The peer-reviewed research assesses the viability of applying a machine learning weather model to global seasonal forecasts, which are vital for understanding global weather patterns. Seasonal forecasts, which look at the likely conditions for the next three months, can provide valuable insights for long-term planning and decision making, including for agriculture, water resources and even public health.

我國首次向全球共用氣候資料產品

《中國氣象局全球氣候資料集》在第4屆中國—東盟氣象合作論壇發佈。《資料集》包括全球地面資料集、全球高空資料集、全球格點重建資料集、中國氣象局全球大氣再分析產品1.5版、風雲氣象衛星多星融合陸面與長波輻射資料集和海洋資料集等6類資料，與國際同類產品品質相當，且支援國際交換，能夠支撐氣象早期預警、防災減災全球治理等應用服務，並支援全球人工智慧技術研發應用和氣候變化研究。

Membership renewal is now more convenient

Payment through Faster Payment System (FPS) is now available (Our FPS ID: 166920512). Support your society, don’t forget to renew your membership!