EMC multi-model ensemble TC track forecast Jiayi Peng*, Yuejian Zhu and Richard Wobus* *IMSG at Environmental Modeling Center Environmental Modeling Center /NCEP/NOAA, Camp Springs, MD 2746 Acknowledgements: EMC Ensemble Team Hurricane Forecast Improvement Project 5 th NCEP Ensemble User Workshop, 1-12 May 211, Laurel, MD
Track forecast error for 29 season (AL+EP+WP) GEFS GEFSbc GFS NAEFS 4 35 3 25 2 15 1 5 12 24 36 48 72 96 12 Cases 24 221 192 164 135 87 56 37 NAEFS is combined from GEFSbc and CMCbc, GEFS-T126L28, GFS-T382L64 2
Models and Data Resolution Members Daily Frequency Forecast Length NCEP ensemble GFS T19L28-7km 2+1, 6, 12, 18 UTC 16 days (384hrs) CMC ensemble ECMWF ensemble GEM(.9)L58-1km IFS T639/319L62-3/6km 2+1, 12 UTC 16 days (384hrs) 5+1, 12 UTC 15 days (36hrs) NCEP deterministic GFS T574L64-27km 1, 16, 12, 18 UTC 192 /384hrs CMC deterministic ECMWF deterministic GEM(.45x.3) L58-33km IFS T1279L91-16km 1, 12 UTC 18/24 hrs (12/z) 1, 12 UTC 24 hrs Data: 1/1~12/31/21 NCEP, CMC and ECMWF TC tracks Our goal: Improve tropical-cyclone track prediction by using NCEP, CMC and ECMWF global ensemble forecast products!
21 multi-model ensemble product (3EMN). 21 hurricanes in Atlantic 1Nautical Mile=1.852km Verification: 3EMN and 6EMX are much better than OFCL. GEMN 3EMN AVNO 6EMX OFCL NCEP (GEFS) 2-member mean NCEP+CMC+ECMWF 9-member mean NCEP (GFS) deterministic run (T574L64) three ensemble+ three deterministic runs weighted-mean OFCL official forecast
21 multi-model ensemble product (3EMN). 12 hurricanes in East Pacific GEMN 3EMN AVNO 6EMX OFCL NCEP (GEFS) 2-member mean NCEP+CMC+ECMWF 9-member mean NCEP (GFS) deterministic run (T574L64) three ensemble+ three deterministic runs weighted-mean OFCL official forecast
21 multi-model ensemble product (3EMN). 19 Typhoons in West Pacific Verification: 3EMN and 6EMX are much better than JTWC. GEMN 3EMN AVNO 6EMX JTWC NCEP (GEFS) 2-member mean NCEP+CMC+ECMWF 9-member mean NCEP (GFS) deterministic run (T574L64) three ensemble+ three deterministic runs weighted-mean JTWC official forecast
2 21 Atlantic: 3EMN/6EMN (3EMN/6EMN -hour delay) 18 16 14 12 1 8 6 3EMN 6EMN OFCL 4 2 12 24 36 48 72 96 12 #CASES 195 174 154 136 118 85 69 55 3EMN---NCEP,CMC, ECMWF 9-member mean 6EMN---three ensemble means+three deterministic runs, 6-member mean
21 Atlantic: 3EMI/6EMI (6-hour TC track interpolation, 3EMN/6EMN 6-hour delay) 25 2 15 1 3EMI 6EMI OFCL 5 12 24 36 48 72 96 12 #CASES 179 165 145 13 115 84 67 51 3EMN---NCEP,CMC, ECMWF 9-member mean 6EMN---three ensemble means+three deterministic runs, 6-member mean
25 21 Atlantic: 3EM2/6EM2 (12-hour TC track interpolation, 3EMN/6EMN 12-hour delay) 2 15 1 3EM2 6EM2 OFCL 5 12 24 36 48 72 96 12 #CASES 173 155 137 122 14 79 62 48 3EMN---NCEP,CMC, ECMWF 9-member mean 6EMN---three ensemble means+three deterministic runs, 6-member mean
25 21 West Pacific: 3EMN/6EMN (3EMN/6EMN -hour delay) 2 15 1 3EMN 6EMN JTWC 5 12 24 36 48 72 96 12 #CASES 154 147 132 112 96 66 41 24 3EMN---NCEP,CMC, ECMWF 9-member mean 6EMN---three ensemble means+three deterministic runs, 6-member mean
21 West Pacific: 3EMI/6EMI (6-hour TC track interpolation, 3EMN/6EMN 6-hour delay) 25 2 15 1 3EMI 6EMI JTWC 5 12 24 36 48 72 96 12 #CASES 138 134 122 15 91 63 38 22 3EMN---NCEP,CMC, ECMWF 9-member mean 6EMN---three ensemble means+three deterministic runs, 6-member mean
21 West Pacific: 3EM2/6EM2 (12-hour TC track interpolation, 3EMN/6EMN 12-hour delay) 3 25 2 15 1 3EM2 6EM2 JTWC 5 12 24 36 48 72 96 12 #CASES 133 126 114 99 84 57 32 21 3EMN---NCEP,CMC, ECMWF 9-member mean 6EMN---three ensemble means+three deterministic runs, 6-member mean
Strike probability AL6: Danielle (21) Ensemble mean track GEMN----NCEP 2-member mean TEMN----CMC 2-member mean UEMN---- ECMWF 5-member mean 3EMN----NCEP+CMC+ECMWF 9-mean
Strike probability WP15: Megi (21) Ensemble mean track GEMN----NCEP 2-member mean TEMN----CMC 2-member mean UEMN---- ECMWF 5-member mean 3EMN----NCEP+CMC+ECMWF 9-mean
Spread/Error (NM) GEFS-T254 next implementation in 211 GFS-T574 T19-Error T19-Spread T254-Error T254-Spread 3 25 2 15 1 5 GFS T574: GFSv9.1, next implementation GEFS T19: GFSv8., current operation GEFS T254: GFSv9.1, next implementation 12 24 36 48 72 96 12 CASES 119 114 1 85 75 56 4 27 Forecast Hours Tropical Storm Tracks (Aug. Sep. 21, for AL, EP and WP)
Conclusions The multi-model ensemble forecast products (NCEP, CMC and ECMWF ensemble forecast) could significantly reduce the 21 TC track forecast error. If the multi-model ensemble forecast products delay 6-hour (12-hour), they are still valuable to the 21 TC track forecast. Please visit http://www.emc.ncep.noaa.gov/gmb/jpeng/tc_ens.html Future plans: Add Navy Ensemble (FNMOC), MetOffice ensemble into this multiple model ensemble forecast system. Add meso-scale models (HWRF, GFDL, SREF, etc.) into this multiple model ensemble forecast system. Develop new consensus /ensemble method. Produce TC intensity multi-model ensemble forecast.
21 Atlantic: Multi-model (6EMX) VS. individual model forecast 3 25 2 15 1 5 GEMN TEMN UEMN AVNO CMH EMH 6EMX 12 24 36 48 72 96 12 #CASES 196 174 154 136 118 85 69 55 GEMN/AVNO----NCEP TEMN/CMH----CMC UEMN/EMH----ECMWF
21 East Pacific: Multi-model (6EMX) VS. individual model forecast 4 35 3 25 2 15 1 GEMN TEMN UEMN AVNO CMH EMH 6EMX 5 12 24 36 48 72 96 12 #CASES 81 66 53 44 36 28 16 9 GEMN/AVNO----NCEP TEMN/CMH----CMC UEMN/EMH----ECMWF
21 West Pacific: Multi-model (6EMX) VS. individual model forecast 3 25 2 15 1 5 GEMN TEMN UEMN AVNO CMH EMH 6EMX 12 24 36 48 72 96 12 #CASES 154 147 132 112 96 66 41 24 GEMN/AVNO----NCEP TEMN/CMH----CMC UEMN/EMH----ECMWF
21 GEFS Bias-correction TCs: AL1-21, EP1-12,WP1-19 25 2 15 1 GEMN BEMN AVNO 5 12 24 36 48 72 96 12 Cases 434 46 357 313 274 21 147 94 GEMN---- NCEP 2-member mean BEMN---- NCEP bias-correction 2-member mean AVNO---- NCEP (GFS) deterministic run (T574L64)