The “YukioroSignal” system, which provides snow load alerts, was developed to inform decision-making regarding snow removal from house roofs. It was launched in Niigata Prefecture in 2018 and expanded to cover all special heavy snowfall areas in Japan, including the Hokkaido, Tohoku, and Hokuriku regions in 2024. The system uses the SNOWPACK model to estimate high-accuracy snow weight from real-time snow depth data published online at observation points. At locations where snow depth gauges are not installed, such as in mountainous areas, snow weight is estimated using inverse distance-weighted interpolation, but accuracy is reduced. To overcome this problem, this study attempted to integrate this information with the snow water equivalent distribution calculated using the simple-layer snow distribution model. To validate this improvement, manual observations of snow weight were performed at 98 sites and compared with simulation results. The accuracy of snow weight estimation at distances far away from snow depth stations was improved. The six-year operation of YukioroSignal showed the additional required information that is vulnerable to damage even with less snowfall, such as vacant houses, and caution of changes in hazard levels by an increase in snowburst in a short period.

1. [1] T. Takahashi, D. Kounsana, W. Yamaguchi, and T. Motoyoshi, “Risk assessment on snow removal based on Heisei 18th snow disaster,” J. of Snow Engineering, Vol.26, No.4, pp. 205-210, 2010 (in Japanese).
2. [2] S. Yamaguchi, S. Nakai, K. Iwamoto, and A. Sato, “Influence of anomalous warmer winter on statistics of measured winter precipitation data,” J. Appl. Meteor. Climatol., Vol.48, No.11, pp. 2403-2409, 2009. https://doi.org/10.1175/2009JAMC2008.1
3. [3] M. Ishizaka, H. Motoyoshi, S. Yamaguchi, S. Nakai, T. Shiina, and K. Muramoto, “Relationships between snowfall density and solid hydrometeors, based on measured size and fall speed, for snowpack modeling applications,” The Cryosphere, Vol.10, Issue 6, pp. 2831-2845, 2016. https://doi.org/10.5194/tc-10-2831-2016
4. [4] M. Ishizaka, “Relations among maximum snow depth, mean air temperature, and precipitation determined from their monthly values in snowy areas of Japan,” J. of the Japanese Society of Snow and Ice, Vol.69, No.5, pp. 591-599, 2007 (in Japanese). https://doi.org/10.5331/seppyo.69.591
5. [5] T. Kimura, “Observation of water equivalent of snow cover by metalwafer,” Report of the National Research Center for Disaster Prevention, No.31, pp. 203-217, 1983 (in Japanese).
6. [6] Y. Tominaga, K. Igarashi, M. Wakui, H. Motoyoshi, and S. Takada, “Development of a semi-fullscale building model to obtain validation data for evaluation model of roof snow load,” AIJ J. of Technology and Design, Vol.27, No.65, pp. 114-118, 2021 (in Japanese). https://doi.org/10.3130/aijt.27.114
7. [7] T. Iyobe and K. Kawashima, “Development of quasi-real-time monitoring system for regional snow cover by utilizing multiple snow data,” J. of Snow Engineering of Japan, Vol.36, No.1, pp. 1-13, 2020 (in Japanese). https://doi.org/10.32120/jsej.36.1_1
8. [8] H. Hirashima, T. Iyobe, K. Kawashima, and H. Sano, “Development of a snow load alert system, ‘YukioroSignal’ for aiding roof snow removal decisions in snowy areas in Japan,” J. Disaster Res., Vol.15. No.6, pp. 688-697, 2020. https://doi.org/10.20965/jdr.2020.p0688
9. [9] H. Lievens, I. Brangers, H. P. Marshall, T. Jonas, M. Olefs, and G. De Lanno, “Sentinel-1 snow depth retrieval at sub-kilometer resolution over the European Alps,” The Cryosphere, Vol.16, No.1, pp. 159-177, 2022. https://doi.org/10.5194/tc-16-159-2022
10. [10] M. Niwano, M. Suya, K. Nagaya, S. Yamaguchi, S. Matoba, I. Harada, and N. Ohkawara, “Estimation of seasonal snow mass balance all over Japan using a high-resolution atmosphere-snow model chain,” SOLA, Vol.18, pp. 193-198, 2022. https://doi.org/10.2151/sola.2022-031
11. [11] K. Motoya, “Total snow water distributions in Tohoku region, Japan, averaged for twenty-seven years: Their application to heavy and light snowfall winters,” Seppyo, Vol.70, No.6, pp. 561-570, 2008 (in Japanese). https://doi.org/10.5331/seppyo.70.6_561
12. [12] K. Motoya, T. Yamazaki, and N. Yasuda, “Evaluating the spatial and temporal distribution of snow accumulation, snowmelts and discharge in a multi basin scale: An application to the Tohoku Region, Japan,” Hydrological Processes, Vol.15, Issue 11, pp. 2101-2129, 2001. https://doi.org/10.1002/hyp.279
13. [13] J. Kondo, T. Nakamura, and T. Yamazaki, “Estimation of the solar and downward atmospheric radiation,” Tenki, Vol.38, pp. 41-48, 1991 (in Japanese)
14. [14] H. Hirashima, K. Nishimura, S. Yamaguchi, A. Sato, and M. Lehning, “Avalanche forecasting in a heavy snowfall area using the snowpack model,” Cold Regions Science and Technology, Vol.51, No.2-3, pp. 191-203, 2008. https://doi.org/10.1016/j.coldregions.2007.05.013
15. [15] H. Hirashima, S. Yamaguchi, K. Kosugi, M. Nemoto, T. Aoki, and S. Matoba, “Validation of the SNOWPACK model using snow pit observation data,” J. of the Japanese Society of Snow and Ice, Vol.77, No.1, pp. 5-16, 2015 (in Japanese). https://doi.org/10.5331/seppyo.77.1_5
16. [16] https://xview.bosai.go.jp/products/snow-weight/ [Accessed April 8, 2024]
17. [17] https://seppyo.bosai.go.jp/snow-weight-japan/ [Accessed April 8, 2024].
18. [18] https://seppyo.bosai.go.jp/snow-weight-hokkaido/ [Accessed April 8, 2024]
19. [19] S. Nakai, T. Sato, A. Sato, H. Hirashima, M. Nemoto, H. Motoyoshi, K. Iwamoto, R. Misumi, I. Kamiishi, T. Kobayashi, K. Kosugi, S. Yamaguchi, O. Abe, and M. Ishizaka, “A Snow Disaster Forecasting System (SDFS) constructed from field observations and laboratory experiments,” Cold Regions Science and Technology, Vol.70, pp. 53-61, 2012. https://doi.org/10.1016/j.coldregions.2011.09.002
20. [20] M. Gallet, A. Atto, F. Karbou, and E. Trouvé, “Wet snow detection from satellite SAR images by machine learning with physical snowpack model labeling,” IEEE J. of Selected Topics in Applied Earth Observations and Remote Sensing, Vol.17, pp. 2901-2912, 2024. https://doi.org/10.1109/JSTARS.2023.3342990
21. [21] M. Hendrick, F. Techel, M. Volpi, T. Olevski, C. Pérez-Guillén, A. van Herwijnen, and J. Schweizer, “Automated prediction of wet-snow avalanche activity in the Swiss Alps,” J. of Glaciology, Vol.69, No.277, pp. 1365-1378, 2023. https://doi.org/10.1017/jog.2023.24
22. [22] https://www.jma.go.jp/jma/kishou/know/kurashi/snow.html [Accessed April 8, 2024]