Summer 2024

Table of Contents: TCC News No. 77
Launch of TCC’s Three-month Guidance Tool................................................................................................................................... 1
Contribution of an Unprecedented Marine Heatwave to Extremely Hot Summer Conditions over Northern Japan in 2023 ............. 3
TCC Expert visit to Bhutan ............................................................................................................................................................... 5
Introduction of WMO RA II Information Sharing for Climate Services on the TCC Website ............................................................... 6

Launch of TCC’s Three-month Guidance Tool
The interactive TCC’s Three-month Guidance Tool has been released as an extension of its one-month version(TCC’s one-month Guidance Tool; TCC News No. 56), simplifying calculation of statistical guidance for any given
station point and supporting operational seasonal forecasts. This handy resource can be accessed at- https://ds.data.jma.go.jp/tcc/tcc/products/model/index.html (lower part; three-month prediction section)- https://extreme.kishou.go.jp/cgi-bin/simple_guidance/index_3mon.cgi (see below for password info)
Users are simply required to input their own past observation data for station points where temperature or
precipitation guidance is to be calculated, in the same format as for TCC’s One-month Guidance Tool. Real-time
forecast and re-forecast gridded data from the TCC operational seasonal ensemble prediction system (CPS) arestored on the app side. After the setting of interactive parameters (initial day, forecast periods and predictor
elements (Figure 1-1)), the following figures and results for the selected forecast period are displayed (Figure 1-2):- Tercile probability map- Tercile probability (colored bars) at stations- Inter-annual time-series representation of tercile probability- Reliability/forecast frequency
For more information, see
https://extreme.kishou.go.jp/tool/simple_guidance/help/
Forecast datasets are updated on the 3rd and middle of every month, and every Monday.
The tool is provided exclusively to support seasonal forecasts by National Meteorological and Hydrological
Services (NMHSs). IDs and passwords are as per the TCC’s One-month Guidance Tool. To request an ID/PW, refer tothe instructions via the above link. The tool is currently operated on an experimental basis, and may be suspended
without notice in the event of malfunction or other issues.
The tool is intended for consideration of seasonal forecasts. All NMHS feedback is welcomed toward future
improvement.
(YAMADA Ken, Tokyo Climate Center)

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Figure 1-1 Parameter settings

Figure 1-2 Guidance-tool output<<Table of contents <Top of this article

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Contribution of an Unprecedented Marine Heatwave to Extremely Hot Summer Conditions
over Northern Japan in 2023
TCC issued a press release regarding contribution of an unprecedented marine heatwave (MHW; unusually highocean temperature) to extremely hot summer conditions over northern Japan in 2023. A summary and a link to thefull article are provided below.
Northern Japan experienced the hottest summer in 2023 (Figure 2-1a). The Japan Meteorological Agency (JMA)
Advisory Panel on Extreme Climatic Events (comprised of prominent climate science academics and researchers)
identified MHWs around northern Japan (Figure 2-1b) in association with prominent poleward meandering of theKuroshio Extension as a potential contributor to northern Japan’s unprecedentedly hot summer in 2023 (TokyoClimate Center, 2023; Takemura et al. 2024).

Figure 2-1 Summer-mean surface air temperature anomalies over Japan in 2023. (b) As in (a), butfor sea surface temperature anomalies. From Sato et al. (2024 Scientific Reports).

Further analysis by a joint research team (comprising TCC/JMA and advisory panel members Prof. Hisashi
Nakamura from the Research Center for Advanced Science and Technology (RCAST) at the University of Tokyo, Prof.
Youichi Tanimoto from Hokkaido University and Dr. Masami Nonaka from the Japan Agency for Marine-Earth
Science and Technology (JAMSTEC)) indicated that the marine conditions contributed to reduced amounts of
low-level cloud and increased insolation, atmospheric heating due to the warm ocean, and anomalous evaporationand an enhanced greenhouse effect (Figure 2-2).
The results of this survey were published online in Scientific Reports on 19 July 2024.
Paper:Authors: Hirotaka Sato, Kazuto Takemura, Akira Ito, Takafumi Umeda, Shuhei Maeda, Youichi Tanimoto, Masami
Nonaka & Hisashi Nakamura
Title：Impact of an unprecedented marine heatwave on extremely hot summer over northern Japan in 2023
Journal：Scientific Reports
DOI：10.1038/s41598-024-65291-y
Press Release by TCC/JMA: https://ds.data.jma.go.jp/tcc/data/news/press_20240815.pdf
Related article by RCAST at The University of Tokyo:
https://www.rcast.u-tokyo.ac.jp/en/news/report/page_00338.html

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Figure 2-2 (a) Schematic of processes involved in the impact of an unprecedented marine heatwave (MHW) on
record-breaking hot summer in 2023 over northern Japan. (b) As in (a), but for atmospheric and oceanic processes
that characterize climatological summertime situation around northern Japan. Based on Sato et al. (2024 ScientificReports).

(SATO Hirotaka, Tokyo Climate Center)
References
Sato, H., K. Takemura, A. Ito, T. Umeda, S. Maeda, Y. Tanimoto, M. Nonaka and H. Nakamura, 2024: Impact of an
unprecedented marine heatwave on extremely hot summer over Northern Japan in 2023. Sci. Rep., 14, 16100.
https://doi.org/10.1038/s41598-024-65291-y
Takemura, K, H. Sato, A. Ito, T. Umeda, S. Maeda, M. Hirai, Y. Tamaki, H. Murai, H. Nakamigawa, Y. N. Takayabu, H. Ueda, R.
Kawamura, Y. Tanimoto, H. Naoe, M. Nonaka, T. Hirooka, H. Mukougawa, M. Watanabe and H. Nakamura, 2024:Preliminary Diagnosis of Primary Factors for an Unprecedented Heatwave over Japan in 2023 Summer. SOLA, 20,69-78. https://doi.org/10.2151/sola.2024-010
Tokyo Climate Center, 2023: Climate characteristics and factors behind heavy rainfall during the Baiu season in 2023 andextremely high temperatures from mid-July onward (press release)https://ds.data.jma.go.jp/tcc/data/news/press_20230928.pdf<<Table of contents <Top of this article

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TCC Expert visit to Bhutan
As part of the Project for Capacity Enhancement of Meteorological Observation, Forecasting and Flood Warning
for Disaster Preparedness and Response in Thimphu and Paro River Basins in Bhutan by the Japan International
Cooperation Agency (JICA) and related capacity development by TCC in its WMO Regional Climate Center function,
TCC experts visited the National Center for Hydrology and Meteorology (NCHM) of Bhutan from 6 to 8 August 2024.
Content encompassed training on medium-to-long range forecasts and the effective use of TCC resources, including
the online Interactive Tool for Analysis of the Climate System (iTacs) and TCC’s Three-month Guidance Toollaunched in July 2024.
With the attendance of seven staff from the NCHM Weather Service Division, the course began with apresentation on inter-annual and intra-seasonal climate system variability relating to seasonal forecasts in Bhutan.
Attendees learned about iTacs usage and climate system analysis associated with observation data in Bhutan, andalso assimilated the expertise and techniques necessary to create long-range forecasts using TCC products (e.g.,
TCC’s Three-month Guidance Tool), and produced forecasts for their own regions for the August – October 2024
period. At the end of the seminar, attendees were divided into two groups for presentations on:- large-scale atmospheric and oceanic variability relevant to Bhutan’s climate- seasonal forecasting for Aug.-Oct. 2024 in Bhutan.
The training was considered a success, with Bhutan attendees clearly learning via excellent presentations toinspire further improvement in medium-to-long range forecasting.
TCC seminars characteristically involve such exercises and presentations to promote understanding ofclimatological dynamics, seasonal forecasting and usage of TCC tools. TCC remains dedicated to its program ofexpert visits to NMHSs in Southeast Asia and elsewhere as necessary to assist with operational climate services.
Thanks are due to the relevant NCHM staff for their kind hospitality and to JICA for providing this outstanding
opportunity.
(YAMADA Ken, MAEDA Shuhei, Tokyo Climate Center)

Practical exercises

Group Photo<<Table of contents <Top of this article

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Introduction of WMO RA II Information Sharing for Climate Services on the TCC Website
Climate services today play increasingly important roles in helping various socio-economic sectors to reduce
related negative impacts and adapt to climate change and global warming. Against such a background, National
Meteorological and Hydrological Services (NMHSs) need to provide high-quality, high-precision climate informationin consideration of accessibility and user needs, and engage in various activities related to the Global Frameworks
for Climate Services (GFCS) WMO initiative to promote utilization of climate information in user sectors.
Enhanced climate services and GFCS implementation require sharing of information on such services, goodpractices and lessons learned in climate-related activities, especially among NMHSs in climatologically similarregions.
To address these issues in WMO Regional Association II (RA II), TCC operates
https://ds.data.jma.go.jp/tcc/RaiiInfoshare/ (TCC News Nos. 36, 50, 67) in response to related decisions taken at the15th and 16th RA II sessions based on questionnaire feedback. TCC remains committed to supporting theimprovement of RA II climate services via its online content.
(TAKAHASHI Kiyotoshi, Tokyo Climate Center)<<Table of contents <Top of this article

JICA Magazine
developing countries
Tokyo Climate Center, Japan Meteorological Agency
3-6-9 Toranomon, Minato City, Tokyo 105-8431, Japan

and/or the TCC website would be muchappreciated.
Please e-mail to tcc@met.kishou.go.jp.
(Editors: HARADA Masashi, TAKAHASHI Kiyotoshi)

TCC Website:<<Table of contents

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