SWIRLS (Short-range Warning of Intense Rainstorms in Localized Systems)

SWIRLS is the operational rainstorm nowcasting system of Hong Kong Observatory (HKO). State-of-the-art techniques are implemented in SWIRLS for analysis and prediction of precipitation and convective weather phenomena in the next few hours. SWIRLS has been in operation in HKO since 1999. SWIRLS was also implemented in various meteorological services or participated in international forecasting projects to support the research and development of rainstorm nowcasting techniques.
SWIRLS Integrated Panel


Year   Title   Author(s)
2017   Development of Satellite Reflectivity Retrieval Technique for Tropical Cyclone Rainfall Nowcasting   Wang-chun WOO, Yin-ying IP*, Wai-kin WONG, Ngo-hin CHAN
2017   Operational Application of Optical Flow Techniques to Radar-Based Rainfall Nowcasting   W.C. Woo, W.K. Wong
2016   自動以日常用語表達降雨、雷暴及大風實況和降雨預測的系統 (in Chinese only)   胡宏俊, 楊海霖, 梁明德
2015   Blending of Extrapolated Radar Reflectivity with Simulated Reflectivity from NWP for a Seamless Significant Convection Forecast up to 6 Hours   P. Cheung, P.W. Li & W.K. Wong
2015   Convolutional LSTM Network: A Machine Learning Approach for Precipitation Nowcasting   Xingjian SHI, Zhourong CHEN, Hao WANG, Dit-Yan YEUNG, Wai-kin WONG, Wang-chun WOO
2015   Experimental Location Specific Probabilistic Rainfall Nowcast   W.C. Woo, K.M. Lok
2014   Use of NWP for Nowcasting Convective Precipitation: Recent Progress and Challenges   Juanzhen Sun, Ming Xue, James W. Wilson, Isztar Zawadzki, Sue P. Ballard, Jeanette Onvlee-Hooimeyer, Paul Joe, Dale M. Barker, P.W. Li, Brian Golding, Mei Xu & James Pinto
2014   An Overview of Nowcasting Development, Applications, and Services in the Hong Kong Observatory   P.W. Li, W.K. Wong, P. Cheung & H.Y. Yeung
2014   Establishing Integrated Weather, Climate, Water, And Related Environmental Services For Megacities And Large Urban Complexes - Initial Guidance   S. GRIMMOND, G. BEIG, B. BROWN, G. CARMICHAEL, CHEN B., FANG Z., G. FLEMING, A. GARCIA, L. JALKANEN, H. KOOTVAL, LI H., K. LONGO, MU H., PENG L., SHI J., TAN J., TANG X., D. TERBLANCHE, WOO W. & ZHANG J.
2014   Challenges and Advances related to TC Rainfall Forecast   W.C. Woo, Wallace HOGSETT, M. MOHAPATRA, Kazuhiko NAGATA, Peter OTTO, QI Liangbo, VO Van Hoa, XU Yinglong
2014   An Algorithm to Enhance Nowcast of Rainfall Brought by Tropical Cyclones Through Separation of Motions   W.C. Woo, K.K. Li, Michael Bala
2014   應對大雨的特別天氣提示自動編制系統 (in Chinese only)   胡宏俊, 楊海霖, 鄭子路
2014   透過校準數值預報模式提升短期定量降雨預報的表現 (in Chinese only)   李健綱, 陳家樂, 胡宏俊, 鄭子路
2013   Development of a guideline for thunderstorm reporting based on radar and lightning location data   P.W. Li, P.W. Chan
2013   Development of Radar-Satellite Blended QPE Technique and Application to Rainfall Nowcasting   C.W. Ng, H.Y. Yeung
2013   對應熱帶氣旋降雨的臨近預報方法 (in Chinese only)   胡宏俊, 鄭子路, 李健綱
2012   Application of optical-flow technique to significant nowcast for terminal areas in Hong Kong   P. Cheung, H.Y. Yeung
2012   Recent developments and applications of the SWIRLS nowcasting system in Hong Kong   H.Y. Yeung
2011   《小渦旋》臨近預報系統在2010上海世博會的應用 (in Chinese only)   鄭子路, 戴建華, 楊漢賢
2011   Application of Radar-Raingauge Co-Kriging to Improve QPE and Quality Control of Real-time Rainfall Data   H.Y. Yeung, C. Man, S.T. Chan, A. Seed
2010   Development of an Advanced Aviation Nowcasting System by Including Rapidly Updated NWP Model in Support of Air Traffic Management   P.W. Li, W.K. Wong
2010   多尺度光流變法在臨近預報的應用和表現 (in Chinese only)   楊漢賢, 黃偉健, 鄭子路
2009   Development of a Thunderstorm Nowcasting System in Support of Air Traffic Management   P.W. Li
2008   Development of a Lightning Nowcasting System for Hong Kong International Airport   P.W. Li, D.S. Lau
2008   A High-resolution Rapidly-updated Meteorological Data Analysis System for Aviation Applications   C.S. Lau, J.T.K. Wan, M.C.Chu & P.W. Li
2008   Thunderstorm Downburst and Radar-based Nowcasting of Squalls   H.Y. Yeung, S.T. Lai, K.Y. Chan
2007   Lightning Initiation and Intensity Nowcasting Based on Isothermal Radar Reflectivity - A Conceptual Model   Linus H.Y. Yeung, Edwin S.T. Lai, Samson K.S. Chiu
2006   Applications of Nowcasting Products to Real-time Warning of Hazardous Weather in Hong Kong   M.C. Wong, S.T. Lai, P.W. Li
2006   Quantitative Precipitation Nowcast of Tropical Cyclone Rainbands - Case Evaluation in 2006   S.T. Lai, W.K. Wong
2006   From SWIRLS to RAPIDS : Nowcast Applications Development in Hong Kong   M.C. Wong, W.K. Wong, S.T. Lai
2006   Application of Rainstorm Nowcast to Real-time Warning of Landslide Hazards in Hong Kong   Sammy P.Y. Cheung, M.C. Wong, Linus H.Y. Yeung
2006   Nowcasting - the Means for Meeting the Server Weather Challenge   Linus H.Y. Yeung
2005   Use of GPS Signal Delay for Real-time Atmospheric Water Vapour Estimation and Rainfall Nowcast in Hong Kong   P.W. Li, X.Y. Wang, Y.Q. Chen, Edwin S.T. Lai
2005   RAPIDS - A New Rainstorm Nowcasting System in Hong Kong   P.W. Li, W.K. Wong, Edwin S.T. Lai
2004   Applications of Radar-based Nowcasting Techniques for Mesoscale Weather Forecasting in Hong Kong   P.W. Li, Edwin S.T. Lai
2004   Short-range Quantitative Precipitation Forecasting in Hong Kong   P.W. Li, Edwin S.T. Lai
2004   利用廣東省自動氣象站網絡實時資料增強香港暴雨臨近預報的能力 (in Chinese only)   李炳華, 周志堅, 楊漢賢
2003   Merging Nowcasting and NWP in Weather Warning Operations, with Special Reference to Landslides   C.C. Lam
2003   臨近預報在城市地質災害中的應用 (in Chinese only)   李炳華, 林超英
2003   Case Study on the Impact of Radar-derived TREC Winds on Model Forecast of Heavy Rain Associated with Landfalling Tropical Cyclone   C.C. Lam
2003   From Radar Echoes to Landslip Warnings   C.Y. Lam, C.C. Lam
2003   臨近預報在香港『山泥傾瀉警告』中的應用 (in Chinese only)   陳建宇, 李炳華
2002   Strategies of Nowcasting and Forecasting Rainstorms in Hong Kong   Edwin S.T. Lai
2001   Short-range rainfall forecast in Hong Kong   Edwin S.T. Lai, P. Cheung
2001   Radar-based Analyses on the Hailstorm of 9 April 2001   Edwin S.T. Lai, P.W. Li
2001   「小渦旋」- 1999及2000年暴雨驗證及最新發展策略 (in Chinese only)   黎守德, 李炳華
2000   SWIRLS - An Evolving Nowcasting System   P.W. Li, W.K. Wong, K.Y. Chan, Edwin S.T. Lai
2000   Pattern Recognition of Radar Echoes for Short-range Rainfall Forecast   Edwin S.T. Lai, P.W. Li, C.M. Chan, M.C. Chu, W.H. Wong
1999   Preliminary Performance Evaluation of A Rainstorm Nowcasting System   Edwin S.T. Lai, P.W. Li
1999   Short-range Forecast of Heavy Rain based on Radar Echo Analysis   P.W. Li, W.K. Wong, Edwin S.T. Lai
1998   暴雨預報中的溫熵圖及大氣穩定情況分析 (in Chinese only)   陳建宇, 黎守德, 李炳華
1998   從雷達回波的移動趨預報短期的降雨情況 (in Chinese only)   黃偉健, 黎守德, 李炳華
1998   TREC Application in Tropical Cyclone Observation   Edwin S.T. Lai


Year   Event
2018   HKO launched for trial operation the regional satellite-based significant convection, super-cool liquid water and ice crystal icing nowcast for aviation applications.
2018   HKO launched a two-hour rainfall and one-hour lightning location-specific nowcasting service on Windows 10 platform. Read More
2018   Lightning nowcast for Ngong Ping 360 began operation.
2017   HKO developed lightning nowcast for Ngong Ping 360 for trial use.
2017   Mr Cheng Tsz-lo, one of the developers of SWIRLS, received the Secretary for the Civil Service's Commendation. Read More
2017   HKO collaborated with Drainage Services Department (DSD), Hong Kong and developed an Early Rainstorm Alarm System for the Kai Tak River Works, winning the "The Association of Consulting Engineers of Hong Kong (ACEHK) Annual Award 2017". Read More or Watch (Chinese only)
2017   The "Big Data Analysis and Decision Support" team, of which STIR being one of the components, won the "Team Award (Internal Service)" under the Civil Service Outstanding Service Award Scheme 2017. Read More
2017   The Hong Kong University of Science and Technology (HKUST) and HKO developed two enhanced deep-learning algorithms on rainfall nowcast, based on Convolutional Gated Recurrent Units (ConvGRU) and Trajectory Gated Recurrent Units (TrajGRU). Read More
2017   HKO launched an one-hour lightning location-specific nowcasting service on HKO's Internet website for the public. Read More or Watch (Chinese only)
2016   The Significant Convection Monitoring and Foreacsting Webpage was put in real-time operation.
2016   An algorithm to simulate radar reflectivity based on Himawari-8 satellite data was developed. Read More
2016   HKO and DSD jointly develop a system, based on SWIRLS, to control the penstock operation in Shuen Wan, Hong Kong, contributing to the improvement of the ecology of the wetland.
2016   HKO hosted the World Meteorological Organization (WMO) WWRP 4th International Symposium on Nowcasting and Very-short-range Forecast 2016 (WSN16) and the WMO WWRP & CAeM Aviation Research Demonstration Project (AvRDP) Training Workshop. Read More
2015   HKO developed blended Radar Reflectivity with Simulated Reflectivity from NWP for Seamless Significant Convection Forecast.
2015   HKO launched the community version of the SWIRLS nowcasting system (Com-SWIRLS). Read More
2015   HKO organised the international workshop on "Rainfall Nowcasting" under the Voluntary Cooperation Programme (VCP) of WMO
2015   HKO and HKUST developed the first deep-learning algorithm on rainfall nowcast. Read More
2014   SIP (SWIRLS Integrated Panel) and ARROW (Automatic Rainstorm Related Objective Warnings) to support rainstorm warning operation in Hong Kong was developed.
2014   The forecast range of SWIRLS was extended from 6 hours to 9 hours based on multi-sensor observations.
2013   The SWIRLS Tropical Cyclone (TC) module was developed. Read More
2013   The application "STIR (Special Tips on Intense Rainfall)" was developed.
2012   HKO launched the Significant Convection Monitoring and Foreacsting Webpage for trial operation on the Aviation Meteorological Information Dissemination System (AMIDS) website.
2012   Location-based rain forecast on MyObservatory launched on a trial basis. Read More
2012   SERN was developed and started trial operation.
2011   HKO started providing lightning nowcast to China Light & Power Hong Kong Limited (CLP). Read More
2011   SWIRLS supported the 2011 Summer Universiade held in Shenzhen, China. Read More
2010   Rainfall nowcast for the Pearl River Delta Region with user-selectable geographical information content launched. Read More
2010   SWIRLS supported the XIX Commonwealth Games in New Delhi, India. Read More
2010   SWIRLS participated in WENS in support of the Shanghai World EXPO. Read More
2010   ATNS went into operational use to provide short-term thunderstorm forecast for the next hour to support Air Traffic Management.
2009   ATLAS won the First Runner-up under the category "Specialised Service" of the 2009 Civil Service Outstanding Service Award. Read More
2009   ATLAS won the Silver Award in the "Best Public Service Application (Small Scale Project) Award" at the Hong Kong Information and Communication Technology (ICT) Awards 2008. Read More
2008   SWIRLS participated in B08FDP in support of the Beijing Olympics Games (B08) Watch (Chinese only)
2007   ATLAS began operation to support lightning warning at the Hong Kong International Airport
2005   RAPIDS began trial run.
2003   "Rainstorm Viewer", a SWIRLS nowcasting tool developed to support the operation of rainstorm warning in Hong Kong
2000   HKO Technical Note No. 100 "SWIRLS - An Evolving Nowcasting System" was published. Read More
1999   SWIRLS became operational in HKO in 1999.
1998   A SWIRLS prototype was put on operational trial.
1997   HKO started the development of the SWIRLS rainstorm nowcasting system.