A Comparison between Hurricane WRF and TWRF in Typhoon Track and Rainfall Forecast over the western North Pacific Chin-Cheng TSAI 1, Ling-Feng HSIAO 1, Der Song CHEN 2, Jian-Wen BAO 3 1 Taiwan Typhoon and Flood Research Institute, Taiwan, 2 Central Weather Bureau, Taiwan, 3 NOAA Earth System Research Laboratory, United States 216/4
Hurricane WRF in Taiwan TTFRI and CWB collaborated with ESRL/NOAA and had successfully implemented the Hurricane WRF(HWRF) model in Taiwan since 212. In Apr. 213, TTFRI and CWB had the operational version of HWRF from EMC. TTFRI had added 2 HWRF members into Taiwan Cooperative Precipitation Ensemble Forecast Experiment (TAPEX) from 212 to 213. HWRF 215 operational version updated in Oct. 215.
Configuration of HWRF Experiment cold/warm analysis bogus Cu. M.P. PBL Note HWRF (M22) cold start NODA HWRF bogus SAS Ferrier NCEP GFS 43levels; P_top 5hPa; 2 way; 27/9/3km; moving; no ocean couple & no GSI; IC&BC from NCEP T574 atmospheric spectral data and include NCEP.5deg data. HWRF_T (M21) cold start NODA no bogus SAS Ferrier NCEP GFS 43levels; P_top 5hPa; 1 way; 45/15/5km; static; no ocean couple & no GSI; IC&BC from NCEP.5deg data. Moving domain Static domain 3
Track error(km) 213-214 TTFRI HWRF vs. EMC HWRF 2 15 213-14EMC_HWRF 213-14TTFRI_HWRF 128 125 156 155 188 188 1 11 94 5 53 28 51 26 75 72 (74) 12(65) 24(593) 36(532) 48(475) 6(417) 72(362) Forecast hour(# of cases)
Configuration of HWRF Experiment cold/warm analysis bogus Cu. M.P. PBL Note HWRF (M22) cold start NODA HWRF bogus SAS Ferrier NCEP GFS 43levels; P_top 5hPa; 2 way; 27/9/3km; moving; no ocean couple & no GSI; IC&BC from NCEP T574 atmospheric spectral data and include NCEP.5deg data. HWRF_T (M21) cold start NODA no bogus SAS Ferrier NCEP GFS 43levels; P_top 5hPa; 1 way; 45/15/5km; static; no ocean couple & no GSI; IC&BC from NCEP.5deg data. Moving domain Static domain 5
The Comparison of HWRF and TWRF in 213 Track Error 25 TS score.45 2 15 1 5 TWRF HWRF_static.4.35.3.25.2.15.1.5.4.38.21.18.33.17.17.9. 5mm 13mm 2mm 35mm 24H-accumulated 6
MSLP of HWRF_T(45/15/5km) has Bull s eye Reduce terrain resolution >> adjust ptsgm level from 2hPa to 42hPa(HWRF) 6/2 18Z +18fhr 7/11 Z +42fhr 6/24 Z +12fhr 7/12 Z +24fhr
Bull s eye of MSLP had significantly reduced when increasing the resolution(27/9/3km) 6/2 18Z +18fhr 6/24 Z +12fhr 7/11 Z +42fhr 7/12 Z +24fhr
Configuration of HWRF Experiment cold/warm analysis bogus Cu. M.P. PBL Note HWRF (M22) cold start NODA HWRF bogus SAS Ferrier NCEP GFS 43levels; P_top 5hPa; 2 way; 27/9/3km; moving; no ocean couple & no GSI; IC&BC from NCEP T574 atmospheric spectral data and include NCEP.5deg data. HWRF_T (M21) cold start NODA no bogus SAS Ferrier NCEP GFS 43levels; P_top 5hPa; 1 way; 45/15/5km 27/9/3km; static; no ocean couple & no GSI; IC&BC from NCEP.5deg data. Moving domain Static domain 9
Cases study for HWRF_T(27/9/3km) Experiments M21:45/15/5 km,e_vert=43 CTL21: 27/9/3 km, e_vert=43 Cases with warning issued by CWB,213 Soulik 7W:TRK:78-1318Z,RAN:12-1212Z Cimaron 8W:TRK:717-1812Z,RAN:18-1812Z Trami 12W:TRK:818-226Z,RAN:21-2112Z Kong-rey 14W:TRK:8266-312Z,RAN:286-2818Z Usagi 17W:TRK:91618-23Z,RAN:218Z-216Z Fitow 22W:TRK:9312-7Z,RAN:56-518Z
Track error(km) Track error of 6 warning TCs 12 cases had been finished 18 16 14 12 1 8 6 4 2 M21 CTL21 113 131 13 93 18 9 53 51 3 168 167 145 147 (12) 12(18) 24(96) 36(84) 48(73) 6(63) 72(53) Forecast hour(# of cases)
24-hour accumulated rainfall for Typhoon FITOW(213) OBS 56Z 512Z 518Z 5km CTL CTL CTL 3km
Precipitation skill score (6 TCs,18cases).6.5.4.3.2.1.52.48 TS.33.24.15.13 5mm 13mm 35mm Threshold M21 CTL21.7.6.5.4.3.2.1.61.54 BS.47.3.26.21 5mm 13mm 35mm Threshold M21 CTL21.4.35.3.25.2.15.1.35.32 ETS.24.18.14 5mm 13mm 35mm Threshold M21 CTL21.12.4.35.3.25.2.15.1.5.9.7 FAR.23.16 5mm 13mm 35mm Threshold.36.36 M21 CTL21
Track Error HWRF with static domain in 214 In typhoon season 214 horizontal resolution :27/9/3 km ; vertical resolution 43 levs But the track performance was poor after 36 forecast hour. 35 3 25 2 typhoon MATMO and FUNG-WONG(214) HWRF_static_28lev_d2 HWRF_static_d2 218 TWRF_d2 192 271 231 335 263 15 1 5 49 45 68 62 64 18 99 74 155 138 98 115 127 15 (36) 12(32) 24(28) 36(24) 48(22) 6(19) 72(12) Forecast hour(# of cases) 14
BIAS BIAS BIAS Threat Score Threat Score Threat Score Rainfall forecast skill score of typhoon FUNG-WONG&MATMO (18 cases).6.5.4.3.2.1 MATMO&FUNG-WONG(214) -24 fhr HWRF_static HWRF_static_28Lev TWRF.6.5.4.3.2.1 5 8 13 2 35 5 Threshold MATMO&FUNG-WONG(214) 24-48 fhr HWRF_static HWRF_static_28Lev TWRF 5 8 13 2 35 5 Threshold.6.5.4.3.2.1 MATMO&FUNG-WONG(214) 48-72 fhr HWRF_static HWRF_static_28Lev TWRF 5 8 13 2 35 5 Threshold 3 2.5 2 1.5 1.5 MATMO&FUNG-WONG(214) -24 fhr HWRF_static HWRF_static_28Lev TWRF 5 8 13 2 35 5 Threshold 3 2.5 2 1.5 1.5 MATMO&FUNG-WONG(214) 24-48 fhr 3 HWRF_static HWRF_static_28Lev TWRF 2.5 2 1.5 1.5 5 8 13 2 35 5 Threshold MATMO&FUNG-WONG(214) 48-72 fhr HWRF_static HWRF_static_28Lev TWRF 5 8 13 2 35 5 Threshold 15
Configuration of HWRF static Experiment cold/warm analysis bogus Cu. M.P. PBL Note HWRF static cold start NODA no bogus SAS Ferrier NCEP GFS 43levels; P_top 5hPa; 1 way; 27/9/3km; static; no ocean couple & no GSI; IC&BC from NCEP.5deg data. HWRF static cold start NODA no bogus BMJ Ferrier NCEP GFS 43levels; P_top 5hPa; 1 way; 27/9/3km; static; no ocean couple & no GSI; IC&BC from NCEP.5deg data. Warning issued by CWB,215 NOUL CHAN-HOM LINFA SOUDELOR GONI DUJUAN Static domain 16
Forecast Track Error of SAS vs BMJ 1 6 2-2 -6-1 HWRF_static_SAS_d2 HWRF_static_BMJ_d2 mean 95%- 95%+ 6 TCs in 215, warning issued by CWB (7) 6(65) 12(6) 18(58) 24(51) 3(44) 36(4) 42(37) 48(32) 54(28) 6(23) 66(19) 72(14) 35 3 25 2 15 1 5 17
95% C.I. Rainfall r.m.s.e. Rainfall forecast ability of SAS and BMJ 6 4 2 766 stations in TAIWAN, 65 initial times 9 8 7 6-2 -4 5 4 3 2 1-6 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 63 65 67 69 71 73 75 77 Forecast Hour SAS_rmse BMJ_rmse mean 95%- 95%+ 18
Summary & future work of Hurricane WRF We successfully implemented HWRF system in Taiwan and evaluated the track and rainfall forecast performance of HWRF over WNP from 213-214. For static domain HWRF configuration with higher vertical(43levs) and horizontal(3 km) resolution can have better capabilities in forecasting typhoon track and rainfall. But it s rainfall forecast ability still poor than TWRF. A sensitivity test of model cumulus scheme had been done to evaluate the track and rainfall forecast ability between SAS and BMJ scheme. 6 TCs cases show that BMJ performs better during 18-24H in track forecast and 25-35H in rainfall forecast. To update the 215 operational HWRF version and continue evaluating the performance over the WNP. 19
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