2023 storms scored: Don, Franklin, Idalia, Lee, Margot, Nigel, Tammy (96 forecasts, issued 00Z)

2023 -- strong El Nino, never seen by any part of the model (full model from raw ERA5):
 lead    n  NatureV1  steering  straight  stay-put  wind err  persist
   6h   96      38km      47km      53km     125km     6.5kt    2.9kt
  12h   95      74km      99km     128km     248km     7.5kt    5.8kt
  18h   94     118km     160km     219km     376km     8.7kt    8.4kt
  24h   89     167km     231km     309km     476km    10.7kt   11.9kt
  36h   88     318km     438km     523km     681km    12.7kt   15.5kt
  48h   82     503km     689km     719km     866km    14.7kt   18.7kt
  72h   75     810km    1146km    1132km    1211km    15.8kt   21.5kt
  96h   68    1175km    1605km    1501km    1516km    17.0kt   24.8kt
 120h   61    1487km    2028km    1868km    1807km    16.1kt   28.0kt

2017 / 2019 / 2021 -- La Nina / neutral held-out seasons, same metrics, same shipped weights:
 lead    n  NatureV1  steering  straight  stay-put  wind err  persist
   6h 1589      39km      54km      53km     140km     6.2kt    3.4kt
  12h 1530      75km     107km     121km     275km     7.8kt    6.6kt
  18h 1471     115km     166km     199km     404km     9.8kt    9.3kt
  24h 1412     163km     233km     283km     527km    11.0kt   11.8kt
  36h 1295     281km     390km     456km     760km    13.8kt   15.7kt
  48h 1187     418km     572km     628km     977km    16.1kt   18.8kt
  72h  997     735km     978km    1002km    1369km    19.5kt   24.2kt
  96h  826    1051km    1377km    1418km    1737km    21.9kt   27.9kt
 120h  677    1374km    1779km    1828km    2081km    22.8kt   31.6kt

per storm, NatureV1 consensus track error (km) at 1 / 2 / 3 days, against physics steering:
  Don       n=14     169 ( 222)     439 ( 577)     858 (1031)
  Franklin  n=21     211 ( 262)     680 ( 944)     827 (1263)
  Idalia    n=13     165 ( 245)     534 ( 718)    1049 (1373)
  Lee       n=13     100 ( 120)     240 ( 378)     325 ( 635)
  Margot    n=11      84 ( 167)     350 ( 522)     678 ( 926)
  Nigel     n=11     292 ( 369)     727 ( 924)    1111 (1429)
  Tammy     n=13     125 ( 223)     441 ( 601)     838 (1295)

landfall probability (2023): Brier vs base rate, and AUC
     6h n  96  landfalls   2  skill vs base rate -8%  AUC 0.81
    12h n  95  landfalls   4  skill vs base rate +6%  AUC 0.86
    18h n  94  landfalls   4  skill vs base rate -0%  AUC 0.86
    24h n  89  landfalls   5  skill vs base rate +3%  AUC 0.84
    36h n  88  landfalls   8  skill vs base rate +10%  AUC 0.89
    48h n  82  landfalls   9  skill vs base rate +10%  AUC 0.87
    72h n  75  landfalls  12  skill vs base rate +30%  AUC 0.92
    96h n  68  landfalls  14  skill vs base rate +40%  AUC 0.95
   120h n  61  landfalls  14  skill vs base rate +42%  AUC 0.94
