Statistical Validation of the Predicted Amount and Start Time of Heavy Rainfall in 2015 Based on the VIL Nowcast Method
Koyuru Iwanami, Kohin Hirano, and Shingo Shimizu
National Research Institute for Earth Science and Disaster Resilience (NIED)
3-1 Tennodai, Tsukuba, Ibaraki 305-0006, Japan
We statistically evaluated the rainfall amount predicted by VIL Nowcast, which is designed using vertically integrated liquid water content (VIL) through experimental data obtained over five months from June to October of 2015. The accuracy of predictions for the start time of heavy rain, which are vital for issuing warnings concerning localized heavy rain, was also reviewed. We revealed that VIL Nowcast could predict the rainfall amount more accurately than conventional methods up to the first 20 min of the evaluation period (30 min in total) with superior accuracy for the start time of severe rain from isolated convective cells in the first 10 min.
-  A. Kato and M. Maki, “Localized heavy rainfall near Zoshigaya, Tokyo, Japan on 5 August 2008 observed by X-band polarimetric radar –preliminary analysis–,” SOLA, Vol.5, pp. 89-92, DOI: 10.2151/sola.2009-023, 2009.
-  D.-S. Kim, M. Maki, S. Shimizu, and D.-I. Lee, “X-Band dual- polarization radar observations of precipitation core development and structure in a multi-cellular storm over Zoshigaya, Japan, on August 5, 2008,” J. Meteor. Soc. Japan, Vol.90, No.5, pp. 701-719, DOI: 10.2151/jmsj.2012-509, 2012.
-  K. Hirano and M. Maki, “Method of VIL calculation for X-band polarimetric radar and potential of VIL for nowcasting of localized severe rainfall -Case study of the Zoshigaya downpour, 5 August 2008-,” SOLA, Vol.6, pp. 89-92, DOI: 10.2151/sola.2010-023, 2010.
-  M. Ishihara, “Radar echo population of air-mass thunderstorms and nowcasting of thunderstorm-induced local heavy rainfalls Part 1: Statistical characteristics,” J. Disaster Res., Vol.8, No.1, pp. 57-68, DOI: 10.20965/jdr.2013.p0057, 2013.
-  M. Ishihara, “Radar echo population of air-mass thunderstorms and nowcasting of thunderstorm-induced local heavy rainfalls Part II: A feasibility study on nowcasting,” J. Disaster Res., Vol.8, No.1, pp. 69-80, DOI: 10.20965/jdr.2013.p0069, 2013.
-  M. Maki, K. Iwanami, R. Misumi, S.-G. Park, H. Moriwaki, K. Maruyama, I. Watabe, D.-I. Lee, M. Jang, H.-K. Kim, V. N. Bringi, and H. Uyeda, “Semi-operational rainfall observations with X-band multi-parameter radar,” Atmosph. Sci. Lett., Vol.6, pp. 12-18, DOI: 10.1002/asl.84, 2005.
-  T. Maesaka, M. Maki, K. Iwanami, S. Tsuchiya, K. Kieda, and A. Hoshi, “Operational rainfall estimation by X-band MP radar network in MLIT, Japan,” Proc. of the 35th Conf. on Radar Meteorology, P11.142, https://ams.confex.com/ams/35Radar/webprogram/Paper191685.html, 2011.
-  A. Masuda and E. Nakakita, “Development of a technique to identify the stage of storm life cycle using X-band polarimetric radar,” J. of Japan Society of Civil Engineers, Ser.B1 (Hydraulic Engineering), Vol.70, No.4, pp. I_ 493-I_498, DOI: 10.2208/jscejhe.70.I_493, 2014 (in Japanese).
-  K. Shimose, S. Shimizu, T. Maesaka, R. Kato, K. Kieda, and K. Iwanami, “Impact of observation operators on low-level wind speed retrieved by variational multiple-Doppler analysis,” SOLA, Vol.12, pp. 215-219, DOI: 10.2151/sola.2016-043, 2016.
-  T. Ushio, T. Wu, and S. Yoshida, “Review of recent progress in lightning and thunderstorm detection techniques in Asia,” Atmos. Res., Vol. 154, pp. 89-102, DOI: 10.1016/j.atmosres.2014.10.001, 2015.
-  T. Adachi, K. Kusunoki, S. Yoshida, K. Arai, and T. Ushio, “High-speed volumetric observation of a wet microburst using X-hand phased array weather radar in Japan,” Mon. Wea. Rev., Vol.38, No.144, pp. 3749-3765, DOI: 10.1175/MWR-D-16-0125.1, 2016.
-  T. Adachi, K. Kusunoki, S. Yoshida, H. Inoue, K. Arai, and T. Ushio, “Rapid volumetric growth of misocyclone and vault-like structure in horizontal shear observed by phased array weather radar,” SOLA, Vol.12, pp. 314-319, DOI: 10.2151/sola.2016-061, 2016.
-  F. Isoda, S. Satoh, and T. Ushio, “Temporal and spatial characteristics of localized rainfall on 26 July 2012 observed by phased array weather radar,” SOLA, Vol.14, pp. 64-68, DOI: 10.2151/sola.2018-011, 2018.
-  M. Dixon and G. Wiener, “TITAN: Thunderstorm identification, tracking, analysis, and nowcasting – A radar-based methodology,” J. Atmos. Oceanic Technol., Vol.10, No.6, pp. 785-797, DOI: 10.1175/1520-0426(1993)010< 0785:TTITAA> 2.0.CO;2, 1993.
-  J. T. Johnson, P. L. MacKeen, A. Witt, E. De W. Mitchell, G. J. Stumpf, M. D. Eilts, and K. W. Thomas, “The storm cell identification and tracking algorithm: An enhanced WSR-88D algorithm,” Wea. Forecasting, Vol.13, No.2, pp. 263-276, DOI: 10.1175/1520-0434(1998)013< 0263:TSCIAT> 2.0.CO;2, 1998.
-  J. Handwerker, “Cell tracking with TRACE3D – A new algorithm,” Atmos. Res., Vol.61, Issue 1, pp. 15-34, DOI: 10.1016/S0169-8095(01)00100-4, 2002.
-  E. Ruzanski, V. Chandrasekar, and Y. Wang, “The CASA nowcasting system,” J. Atmos. Oceanic Technol., Vol.28, No.5, pp. 640-655, DOI: 10.1175/2011JTECHA1496.1, 2011.
-  S. Yoshida, R. Misumi, S. Shimizu, T. Maesaka, K. Iwanami, and M. Maki, “Validation of short-term forecasting of meso-γ-scale convective systems based on a cell-tracking system,” SOLA, Vol.8, pp. 141-144, DOI: 10.2151/sola.2012-035, 2012.
-  S. Kigawa, “High resolution precipitation nowcast in Japan Meteorological Agency,” Kenkyu-Jihou, Vol.81, pp. 55-76, 2014 (in Japanese).
-  J. Sun and N. A. Crook, “Dynamical and microphysical retrieval from Doppler radar observations using a cloud model and its adjoint. Part I: Model development and simulated data experiments,” J. Atmos. Sci., Vol.54, No.12, pp. 1642-1661, DOI: 10.1175/1520-0469(1997)054< 1642:DAMRFD> 2.0.CO;2, 1997.
-  M. Hu, M. Xue, J. Gao, and K. Brewster, “3DVAR and cloud analysis with WSR-88D level-II data for the prediction of the Fort Worth, Texas, tornadic thunderstorms Part II: Impact of radial velocity analysis via 3DVAR,” Mon. Weather Rev., Vol.134, No.2, pp. 699-721, DOI: 10.1175/MWR3093.1, 2006.
-  J. Gao and D. J. Stensrud, “Assimilation of reflectivity data in a convective-scale, cycled 3DVAR framework with hydrometeor classification,” J. Atmos. Sci., Vol.69, No.3, pp. 1054-1065, DOI: 10.1175/JAS-D-11-0162.1, 2012.
-  O. Caumont, V. Ducrocq, E. Wattrelot, G. Jaubert, and S. Pradier-Vabre, “1D+3Dvar assimilation of radar reflectivity data: a proof of concept,” Tellus, Vol.62A, Issue 2, pp. 173-187, DOI: 10.1111/j.1600-0870.2009.00430.x, 2010.
-  H. Wang, J. Sun, S. Fan, and X.-Y. Huang, “Indirect assimilation of radar reflectivity with WRF 3D-Var and its impact on prediction of four summertime convective events,” J. Appl. Meteorol. Climatol., Vol.52, No.4, pp. 889-902, DOI: 10.1175/JAMC-D-12-0120.1, 2013.
-  K. Hirano and M. Maki, “Imminent nowcasting for severe rainfall using vertically integrated liquid water content derived from X-band polarimetric radar,” J. of the Meteorological Society of Japan. Vol.96A, pp. 201-220, DOI: 10.2151/jmsj.2018- 028, 2018.
-  S. Otsuka, G. Tuerhong, R. Kikuchi, Y. Kitano, Y. Taniguchi, J. J. Ruiz, S. Satoh, T. Ushio, and T. Miyoshi, “Precipitation nowcasting with three-dimensional space–time extrapolation of dense and frequent phased-array weather radar observations,” Wea. Forecasting, Vol.31, No.1, pp. 329-340, DOI: 10.1175/WAF-D-15-0063.1, 2016.
-  R. Kato, S. Shimizu, K. Shimose, T. Maesaka, K. Iwanami, and H. Nakagaki, “Predictability of meso-γ-scale, localized, extreme heavy rainfall during the warm season in Japan using high- resolution precipitation nowcasts,” Quart. J. Roy. Meteor. Soc., Vol.143, pp. 1406-1420, DOI: 10.1002/qj.3013, 2017.
-  U. Germann and I. Zawadzki, “Scale-dependence of the predictability of precipitation from continental radar images. Part I: Description of the methodology,” Mon. Wea. Rev., Vol.130, No.12, pp. 2859-2873, DOI: 10.1175/1520- 0493(2002)130< 2859:SDOTPO> 2.0.CO;2, 2002.
-  B. Boudevillain, H. Andrieu, and N. Chaumerliac, “Evaluation of RadVil, a radar-based very short-term rainfall forecasting model,” J. of Hydrometeorology, Vol.7, No.1, pp. 178-189, DOI: 10.1175/JHM481.1, 2006.
-  A. Kato, M. Maki, K. Iwanami, R. Misumi, and T. Maesaka, “Nowcasting of Precipitation Based on Complementary Application of X-band Polarimetric Radar and C-band Conventional Radar,” J. Japan Soc. Hydrol. and Water Resour., Vol.22, pp. 372-385, DOI: 10.3178/jjshwr.22.372, 2009 (in Japanese).
-  J. T. Schaefer, “The critical success index as an indicator of warning skill,” Wea. Forecasting, Vol.5, No.4, pp. 570-575, DOI: 10.1175/1520-0434(1990)005< 0570:TCSIAA> 2.0.CO;2 , 1990.