Verification of tracks made of Sally

December 07, 2020

I made four tracks of Hurricane Sally, before it was assessed as a tropical cyclone. I made two more tracks after that point. Additionally, within 480 hours of cyclogenesis, there were three instances, when I missed cyclogenesis entirely.

As of this analysis, best track positions are available September 10, 06Z thru September 18, 00Z, and as such, position comparisons are possible only for this timespan.

Since I give only SSHS categories in my tracks, I don't calculate intensity errors in units of speed, but in categories. For this purpose, I define tropical or subtropical storms as "Category 0", tropical or subtropical depressions as "Category -1" and non-existence of a tropical or subtropical cyclone as "Category -2".

In the four tracks (made before operationally recognized cyclogenesis), formation times ranged between September 8, 00Z and September 10, 18Z. Average was September 9, 15Z and median was September 9, 21Z.

In the eight cases (5 tracks, before the tracks and data agreed, that Category 2 would remain the peak intensity, and 3 complete misses), peak intensity ranged between Category -2 and Category 3. Average and median were Category 0.5.

In the six tracks (made before operationally recognized extratropical transition), dissipation times ranged between September 13, 06Z and September 18, 00Z. Average was September 16, 08Z and median was September 17, 00Z.

At the lead time of 1 day (24 hours), there were 2 hits, 0 false detections and 0 misses. 2 available position comparisons produce an average error of 18 nautical miles.

At the lead time of 2 days (48 hours), there were 1 hit, 0 false detections and 0 misses. 1 available position comparison produces an average error of 54 nautical miles.

At the lead time of 3 days (72 hours), there were 1 hit, 0 false detections and 0 misses. 1 available position comparison produces an average error of 97 nautical miles.

At the lead time of 4 days (96 hours), there were 1 hit, 0 false detections and 0 misses. 1 available position comparison produces an average error of 231 nautical miles.

At the lead time of 5 days (120 hours), there were 0 hits, 0 false detections and 1 miss. 1 available position comparison produces an average error of 364 nautical miles.

At the lead time of 6 days (144 hours), there were 0 hits, 0 false detections and 1 misses. No available position comparisons.

At the lead time of 7 days (168 hours), there were 0 hits, 0 false detections and 1 miss. No available position comparisons.

At the lead time of 8 days (192 hours), there were 0 hits, 0 false detections and 1 miss. No available position comparisons.

At the lead time of 9 days (216 hours), there were 0 hits, 1 false detection and 2 misses. No available position comparisons.

At the lead time of 10 days (240 hours), there were 0 hits, 1 false detection and 2 misses. No available position comparisons.

At the lead time of 11 days (264 hours), there were 0 hits, 3 false detections and 2 misses. 2 available position comparisons produce an average error of 416 nautical miles.

At the lead time of 12 days (288 hours), there were 1 hit, 2 false detections and 1 miss. 3 available position comparisons produce an average error of 391 nautical miles.

At the lead time of 13 days (312 hours), there were 2 hits, 1 false detection and 1 miss. 3 available position comparisons produce an average error of 292 nautical miles.

At the lead time of 14 days (336 hours), there were 3 hits, 0 false detections and 1 miss. 3 available position comparisons produce an average error of 247 nautical miles.

At the lead time of 15 days (360 hours), there were 3 hit, 0 false detections and 0 misses. 3 available position comparisons produce an average error of 237 nautical miles.

At the lead time of 16 days (384 hours), there were 2 hits, 0 false detections and 2 misses. 2 available position comparisons produce an average error of 315 nautical miles.

At the lead time of 17 days (408 hours), there were 1 hit, 0 false detections and 3 misses. 1 available position comparison produces an average error of 533 nautical miles.

At the lead time of 18 days (432 hours), there were 1 hit, 1 false detection and 2 misses. 2 available position comparisons produce an average error of 809 nautical miles.

At the lead time of 19 days (456 hours), there were 2 hits, 0 false detections and 1 miss. 2 available position comparisons produce an average error of 944 nautical miles.

At the lead time of 20 days (480 hours), there were 0 hits, 0 false detections and 2 misses. No available position comparisons.

Circle coloration scheme