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Days 1–5. Compared with the National Weather Service forecast from the same hour. No one pays for a rank.

Hurricane tracks

Post-Tropical Cyclone Milton Model Accuracy: GFS vs GEFS mean vs Canadian GEM

Final advisory

NHC issued its final advisory at 2:00 PM ET Thu, Oct 10; Milton is now a post-tropical cyclone.

Post-Tropical Cyclone Milton has 33 positions on the best track, which is where the storm actually went, from the operational NHC file. 4 official forecast tracks are drawn. At 48 hours, the average track miss is 142 miles across 18 forecasts. At 48 hours, the official wind forecast averaged 107 mph and where the storm actually went averaged 119 mph. Stored model tracks on these forecast tracks: GFS, GEFS mean, Canadian GEM, UKMET, HAFS-A, HAFS-B, HWRF, HMON, NAVGEM.

AL142024 · 2024 · Oct 4-11, 2024. Score table. Damage reports.

How to read this. The solid line is where the storm went. A dashed line is where the official forecast said it would go. A smaller path miss is closer. Distances are statute miles. Wind speeds are miles per hour.

The technical details

Path miss on this page is the great-circle distance in statute miles, the same miles as the home card and the score table. The Earth radius is 3,958.7613 miles. The file also keeps that distance in nautical miles. One nautical mile is 1,852 meters, about 1.15 statute miles. A case counts when that forecast and the best track (BEST, lead 0) share the same valid time. Positions are not interpolated. A model track counts even when that cycle has no official forecast yet. Skill against the official forecast (OFCL) still requires the official forecast from the same issue time and lead.

Shown leads are 12, 24, 36, 48, 60, 72, 96, and 120 hours, once a paired fix exists. Sample size is the number of paired cases at that lead. Overall rank still uses 24, 48, 72, and 120 hours. The 96-hour lead is drawn when the deck has a paired fix, and it is not in that rank.

Wind on this page is miles per hour. The file stores maximum wind in knots. One knot is about 1.15 miles per hour. An advisory wind is rounded to the nearest 5 mph. A mean on this page is rounded to the nearest mile per hour. Wind miss is the absolute difference on the paired cases. There is no confidence interval on this map. The daily board’s interval is a 95% percentile bootstrap.

Overall rank is the average of the path rank and the wind rank on this storm. Each rank uses the graded leads at 24, 48, 72, and 120 hours, and each of those leads counts once, however many forecasts it holds. A lower miss is the better rank. A tie shares the average of the places those forecasts occupy. A source is ranked only with at least 3 graded forecasts for path and 3 for wind. Fewer than that says Not enough forecasts yet. A source with no graded path, or no graded wind, is left out of both ranks, and overall shows —.

The best track is the operational NHC b-deck. It is preliminary and revised after the season. HURDAT2 is not loaded. Model lines come from the public a-deck for the same forecast tracks, and only when that file stores them. Google DeepMind is the Weather Lab operational ensemble mean. WeatherNext 3 is that model’s ensemble mean from the same download. ECMWF AIFS, ECMWF HRES, and the ECMWF ENS mean are tropical-cyclone tracks from ECMWF open data. The ECMWF ENS mean is the average of the member centers in the IFS ensemble track file. AI GFS is NOAA’s AIGFS tracker when that file is still posted. The methodology page names the aids that are scored.

The methodology page is the full reference. How we grade says the same rules in plain English.

The best track is the operational NHC b-deck. It is preliminary and is revised after the season. The post-season HURDAT2 track is not loaded.

This score uses the archived NHC b-deck and a-deck for this storm. The post-season HURDAT2 file is not loaded.

Google DeepMind, WeatherNext 3, ECMWF AIFS, ECMWF HRES, ECMWF ENS mean, AI GFS: No graded forecasts yet.

Overall rank

Overall averages each forecast's rank on path and on wind strength. See the separate scores below.

Place on this list. 1 was closest to the weather that happened. A tie shares this number, and the next place skips ahead. Early read until the longer day count, then proven. The forecast source this row scores. Path and wind ranksOverall averages each forecast's rank on path and on wind strength. See the separate scores below. Track rankPlace on path miss. 1 was closest. On one storm this is that place. Across storms it is the average of those places. Each graded lead counts once. A tie shares the average place. Intensity rankPlace on wind miss. 1 was closest. On one storm this is that place. Across storms it is the average of those places. Each graded lead counts once. A tie shares the average place.
1 HAFS-A 2 1 3
1 HAFS-B 2 3 1
3 NHC official 3 2 4
4 HMON 4 6 2
5 GFS 5.5 5 6
6 HWRF 6.5 8 5
7 NAVGEM 7 7 7
7 UKMET 7 4 10
9 GEFS mean 8.5 9 8
10 Canadian GEM 9.5 10 9

How we grade

Track and intensity by model

Each row is one source at one lead that has already verified, including 12, 24, 36, and 48 hours. The count is how many forecasts shared a time with where the storm went. Path miss is statute miles. Wind miss is miles per hour. The rank number is that source's place in the table above, and it still uses 24, 48, 72, and 120 hours.

Place on this list. 1 was closest to the weather that happened. A tie shares this number, and the next place skips ahead. Early read until the longer day count, then proven. The forecast source this row scores. LeadHow many hours ahead this forecast was made. Scored leads are 24, 48, 72, and 120. The technical name is lead. CasesHow many past forecasts went into this average. A forecast counts only when the best track has a fix at that exact time. The technical name is cases. Track errorAverage how far the predicted storm path was from where it actually went, in miles. Lower is better. The technical name is track error. Track skillHow that path miss compares with the official hurricane forecast. Positive means better than the official forecast. Negative means worse. The technical name is track skill. Intensity errorAverage how far off the predicted wind speed was, in miles per hour. The file stores knots. Lower is better. The technical name is intensity error. Intensity skillHow that wind miss compares with the official hurricane forecast. Positive means better. Negative means worse. The technical name is intensity skill.
1 HAFS-A 12 h 22 24 mi Beats the official forecast by 15% 12 mph Behind the official forecast by 16%
1 HAFS-A 24 h 22 43 mi Beats the official forecast by 26% 18 mph Behind the official forecast by 7%
1 HAFS-A 36 h 21 63 mi Beats the official forecast by 39% 16 mph Beats the official forecast by 16%
1 HAFS-A 48 h 19 90 mi Beats the official forecast by 38% 20 mph Beats the official forecast by 20%
1 HAFS-A 60 h 17 103 mi Beats the official forecast by 37% 17 mph Beats the official forecast by 47%
1 HAFS-A 72 h 15 116 mi Beats the official forecast by 34% 15 mph Beats the official forecast by 29%
1 HAFS-A 96 h 11 164 mi Behind the official forecast by 26% 18 mph Behind the official forecast by 31%
1 HAFS-A 120 h 7 230 mi Behind the official forecast by 65% 11 mph Behind the official forecast by 253%
1 HAFS-B 12 h 22 23 mi Beats the official forecast by 25% 16 mph Behind the official forecast by 41%
1 HAFS-B 24 h 22 40 mi Beats the official forecast by 31% 15 mph Beats the official forecast by 12%
1 HAFS-B 36 h 21 54 mi Beats the official forecast by 49% 14 mph Beats the official forecast by 27%
1 HAFS-B 48 h 19 77 mi Beats the official forecast by 47% 21 mph Beats the official forecast by 19%
1 HAFS-B 60 h 17 107 mi Beats the official forecast by 34% 22 mph Beats the official forecast by 29%
1 HAFS-B 72 h 15 128 mi Beats the official forecast by 26% 15 mph Beats the official forecast by 46%
1 HAFS-B 96 h 11 188 mi Behind the official forecast by 48% 16 mph Beats the official forecast by 21%
1 HAFS-B 120 h 7 267 mi Behind the official forecast by 98% 10 mph Behind the official forecast by 287%
3 NHC official 12 h 22 29 mi — 10 mph —
3 NHC official 24 h 22 60 mi — 16 mph —
3 NHC official 36 h 20 104 mi — 18 mph —
3 NHC official 48 h 18 142 mi — 25 mph —
3 NHC official 60 h 16 156 mi — 24 mph —
3 NHC official 72 h 14 166 mi — 20 mph —
3 NHC official 96 h 10 124 mi — 12 mph —
3 NHC official 120 h 6 143 mi — 3 mph —
4 HMON 12 h 22 21 mi Beats the official forecast by 30% 19 mph Behind the official forecast by 87%
4 HMON 24 h 22 39 mi Beats the official forecast by 33% 18 mph Behind the official forecast by 11%
4 HMON 36 h 21 70 mi Beats the official forecast by 31% 23 mph Behind the official forecast by 30%
4 HMON 48 h 19 108 mi Beats the official forecast by 24% 21 mph Beats the official forecast by 11%
4 HMON 60 h 17 118 mi Beats the official forecast by 25% 22 mph Beats the official forecast by 22%
4 HMON 72 h 15 131 mi Beats the official forecast by 21% 14 mph Beats the official forecast by 28%
4 HMON 96 h 11 194 mi Behind the official forecast by 63% 14 mph Behind the official forecast by 10%
4 HMON 120 h 7 359 mi Behind the official forecast by 182% 11 mph Behind the official forecast by 147%
5 GFS 12 h 23 24 mi Beats the official forecast by 21% 40 mph Behind the official forecast by 302%
5 GFS 24 h 23 39 mi Beats the official forecast by 30% 36 mph Behind the official forecast by 118%
5 GFS 36 h 22 72 mi Beats the official forecast by 24% 40 mph Behind the official forecast by 121%
5 GFS 48 h 20 115 mi Beats the official forecast by 12% 42 mph Behind the official forecast by 63%
5 GFS 60 h 18 155 mi Behind the official forecast by 7% 39 mph Behind the official forecast by 39%
5 GFS 72 h 16 188 mi Behind the official forecast by 20% 35 mph Behind the official forecast by 52%
5 GFS 96 h 12 219 mi Behind the official forecast by 85% 23 mph Behind the official forecast by 48%
5 GFS 120 h 8 210 mi Behind the official forecast by 64% 16 mph Behind the official forecast by 167%
6 HWRF 12 h 22 24 mi Beats the official forecast by 20% 15 mph Behind the official forecast by 43%
6 HWRF 24 h 22 44 mi Beats the official forecast by 22% 14 mph Beats the official forecast by 14%
6 HWRF 36 h 21 75 mi Beats the official forecast by 27% 17 mph Beats the official forecast by 9%
6 HWRF 48 h 19 133 mi Beats the official forecast by 5% 19 mph Beats the official forecast by 23%
6 HWRF 60 h 17 163 mi Behind the official forecast by 7% 24 mph Beats the official forecast by 12%
6 HWRF 72 h 15 195 mi Behind the official forecast by 21% 22 mph Behind the official forecast by 17%
6 HWRF 96 h 11 250 mi Behind the official forecast by 114% 19 mph Behind the official forecast by 68%
6 HWRF 120 h 7 338 mi Behind the official forecast by 164% 25 mph Behind the official forecast by 667%
7 UKMET 12 h 12 31 mi Beats the official forecast by 1% 61 mph Behind the official forecast by 551%
7 UKMET 24 h 12 48 mi Beats the official forecast by 22% 57 mph Behind the official forecast by 253%
7 UKMET 36 h 11 74 mi Beats the official forecast by 23% 67 mph Behind the official forecast by 304%
7 UKMET 48 h 10 105 mi Beats the official forecast by 14% 73 mph Behind the official forecast by 166%
7 UKMET 60 h 9 154 mi Behind the official forecast by 18% 87 mph Behind the official forecast by 163%
7 UKMET 72 h 8 176 mi Behind the official forecast by 36% 81 mph Behind the official forecast by 256%
7 UKMET 96 h 6 170 mi Behind the official forecast by 67% 62 mph Behind the official forecast by 560%
7 UKMET 120 h 2 209 mi Behind the official forecast by 141% 84 mph —
7 NAVGEM 12 h 11 35 mi Behind the official forecast by 18% 53 mph Behind the official forecast by 500%
7 NAVGEM 24 h 11 60 mi Behind the official forecast by 8% 42 mph Behind the official forecast by 238%
7 NAVGEM 36 h 10 83 mi Beats the official forecast by 15% 44 mph Behind the official forecast by 146%
7 NAVGEM 48 h 9 111 mi Beats the official forecast by 12% 43 mph Behind the official forecast by 83%
7 NAVGEM 60 h 8 127 mi Beats the official forecast by 4% 33 mph Behind the official forecast by 51%
7 NAVGEM 72 h 7 144 mi Behind the official forecast by 3% 23 mph Behind the official forecast by 8%
7 NAVGEM 96 h 5 245 mi Behind the official forecast by 109% 36 mph Behind the official forecast by 162%
7 NAVGEM 120 h 3 395 mi Behind the official forecast by 198% 10 mph Behind the official forecast by 420%
9 GEFS mean 12 h 23 25 mi Beats the official forecast by 16% 52 mph Behind the official forecast by 427%
9 GEFS mean 24 h 23 49 mi Beats the official forecast by 13% 52 mph Behind the official forecast by 222%
9 GEFS mean 36 h 22 87 mi Beats the official forecast by 10% 55 mph Behind the official forecast by 211%
9 GEFS mean 48 h 20 130 mi Behind the official forecast by 1% 58 mph Behind the official forecast by 133%
9 GEFS mean 60 h 18 167 mi Behind the official forecast by 19% 59 mph Behind the official forecast by 123%
9 GEFS mean 72 h 16 183 mi Behind the official forecast by 22% 53 mph Behind the official forecast by 128%
9 GEFS mean 96 h 12 196 mi Behind the official forecast by 81% 41 mph Behind the official forecast by 143%
9 GEFS mean 120 h 8 331 mi Behind the official forecast by 183% 17 mph Behind the official forecast by 240%
10 Canadian GEM 12 h 12 24 mi Beats the official forecast by 24% 53 mph Behind the official forecast by 540%
10 Canadian GEM 24 h 12 45 mi Beats the official forecast by 19% 55 mph Behind the official forecast by 287%
10 Canadian GEM 36 h 11 64 mi Beats the official forecast by 28% 61 mph Behind the official forecast by 284%
10 Canadian GEM 48 h 10 107 mi Beats the official forecast by 10% 64 mph Behind the official forecast by 177%
10 Canadian GEM 60 h 9 140 mi Behind the official forecast by 11% 68 mph Behind the official forecast by 175%
10 Canadian GEM 72 h 8 177 mi Behind the official forecast by 36% 64 mph Behind the official forecast by 162%
10 Canadian GEM 96 h 6 308 mi Behind the official forecast by 226% 48 mph Behind the official forecast by 138%
10 Canadian GEM 120 h 4 509 mi Behind the official forecast by 320% 25 mph Behind the official forecast by 520%

How we grade

Google DeepMind, WeatherNext 3, ECMWF AIFS, ECMWF HRES, ECMWF ENS mean, AI GFS: No graded forecasts yet.

Track map

The solid line is the best track. Dashed lines are official forecast tracks from a few advisories, from the issue position out through the leads stored in that advisory. Thinner lines are model tracks from NHC’s public a-deck for those same advisories, and only when that file actually contains them. Google DeepMind and WeatherNext 3 are ensemble-mean tracks from Weather Lab, drawn on those same advisories. ECMWF AIFS, ECMWF HRES, and the ECMWF ENS mean are open-data cyclone tracks, drawn the same way. AI GFS is NOAA’s AIGFS tracker, drawn when that file is still posted.

17°N 29°N 40°N 52°N 103°W 78°W 53°W 28°W
Map of Post-Tropical Cyclone Milton. The best track, where the storm actually went, has 33 positions. 4 official forecast tracks are drawn. Model lines: GFS, GEFS mean, Canadian GEM, UKMET, HAFS-A, HAFS-B, HWRF, HMON, NAVGEM. Latitude and longitude, scaled by the cosine of the mid-latitude so a degree of longitude is not stretched.
  • Actual track (33 positions)
  • NHC official Oct 5, 12:00 UTC
  • NHC official Oct 7, 06:00 UTC
  • NHC official Oct 9, 00:00 UTC
  • NHC official Oct 10, 18:00 UTC
  • GFS
  • GEFS mean
  • Canadian GEM
  • UKMET
  • HAFS-A
  • HAFS-B
  • HWRF
  • HMON
  • NAVGEM

The chart measures how far the track was off in statute miles, the same miles as the home card. It includes 12, 24, 36, 48, 60, 72, 96, and 120 hours when a paired fix exists. The overall rank uses 24, 48, 72, and 120 hours. Positions are not interpolated.

How far the track was off

29 mi 12 h 60 mi 24 h 104 mi 36 h 142 mi 48 h 156 mi 60 h 166 mi 72 h 124 mi 96 h 143 mi 120 h
Average official track miss in miles by how far ahead. 12 hours 29 miles over 22 forecasts. 24 hours 60 miles over 22 forecasts. 36 hours 104 miles over 20 forecasts. 48 hours 142 miles over 18 forecasts. 60 hours 156 miles over 16 forecasts. 72 hours 166 miles over 14 forecasts. 96 hours 124 miles over 10 forecasts. 120 hours 143 miles over 6 forecasts.
LeadHow many hours ahead this forecast was made. This map shows 12, 24, 36, 48, 60, 72, 96, and 120 when a paired fix exists. Overall rank uses 24, 48, 72, and 120. The technical name is lead. CasesHow many past forecasts went into this average. A forecast counts only when the best track has a fix at that exact time. The technical name is cases. Track errorAverage how far the predicted storm path was from where it actually went, in statute miles. Lower is better. The technical name is track error. Intensity errorAverage how far off the predicted wind speed was, in miles per hour, on this page. Lower is better. The file stores knots. The technical name is intensity error. Forecast max windAverage top wind in the official forecast, in miles per hour, on the paired cases. The file stores knots. The technical name is forecast maximum wind. Best-track windAverage top wind where the storm actually went, in miles per hour, at the same times. The file stores knots. The technical name is best-track wind.
12 h 22 29 mi 10 mph 112 mph 111 mph
24 h 22 60 mi 16 mph 109 mph 112 mph
36 h 20 104 mi 18 mph 108 mph 116 mph
48 h 18 142 mi 25 mph 107 mph 119 mph
60 h 16 156 mi 24 mph 103 mph 114 mph
72 h 14 166 mi 20 mph 98 mph 108 mph
96 h 10 124 mi 12 mph 85 mph 89 mph
120 h 6 143 mi 3 mph 69 mph 66 mph

Miles are statute miles. Wind is miles per hour. The National Hurricane Center file stores wind in knots. One knot is about 1.15 miles per hour. Nautical miles are in the technical details.

How we grade

Top wind

12 h 24 h 36 h 48 h 60 h 72 h 96 h 120 h
Top wind, official forecast versus where the storm went. At 12 hours the forecast averaged 112 mph and where the storm actually went averaged 111 mph. At 24 hours the forecast averaged 109 mph and where the storm actually went averaged 112 mph. At 36 hours the forecast averaged 108 mph and where the storm actually went averaged 116 mph. At 48 hours the forecast averaged 107 mph and where the storm actually went averaged 119 mph. At 60 hours the forecast averaged 103 mph and where the storm actually went averaged 114 mph. At 72 hours the forecast averaged 98 mph and where the storm actually went averaged 108 mph. At 96 hours the forecast averaged 85 mph and where the storm actually went averaged 89 mph. At 120 hours the forecast averaged 69 mph and where the storm actually went averaged 66 mph.
  • Official forecast maximum wind
  • Best-track maximum wind

Source: National Hurricane Center / NOAA. The operational b-deck and the public a-deck are U.S. government works in the public domain. Google DeepMind and WeatherNext 3 ensemble means are experimental forecasts from Google DeepMind Weather Lab. Forecasts older than 48 hours are used under CC BY 4.0. ECMWF AIFS, ECMWF HRES, and ECMWF ENS tracks are ECMWF open data, used under CC BY 4.0. AI GFS tracks are a NOAA AIGFS product. Forecast Scoreboard is not affiliated with NHC, NOAA, Google, or ECMWF.