Verification of tracks made on Alberto using GEFS mean fields

Originally, I made 82 tracks about Subtropical Storm Alberto, from 77 GEFS runs. Since the five "duplicate Albertos" didn't have temporal overlap, they are hereafter considered to be one track. So, I made 77 tracks. Additionally, within 384 hours of cyclogenesis, there were four cases, where I missed cyclogenesis entirely. The technique began showing cyclogenesis very prematurely, similar to GFS and FV3. Position errors were pretty variable. First, the tracks showed a short-lived depression. Then, they showed a strong hurricane. Finally they showed a tropical or subtropical storm, but the long persistence as cyclone overland was entirely missed.

As of this analysis, best track positions are available May 20, 18Z thru May 29, 06Z, 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 subtropicals depressions as "Category -1" and non-existence of a tropical or subtropical cyclone as "Category -2".

In the 77 tracks, formation times ranged between May 11, 00Z and May 28, 12Z. Average was May 19, 02Z and median was May 17, 00Z.

In the 81 cases (77 tracks and 4 complete misses), peak intensity ranged between Category -2 and Category 5. Average was Category 0.62 and median was Category 0.

In the 77 tracks, dissipation times ranged between May 12, 12Z and May 30, 12Z. Average was May 22, 16Z and median was May 23, 00Z. Crossover to Eastern Pacific is considered equal to dissipation.

At the lead time of 1 day (24 hours), there were 0 hits, 2 false detections and 1 misses. 2 available position comparisons produce an average error of 48 nautical miles.

At the lead time of 2 days (48 hours), there were 1 hits, 1 false detections and 4 misses. 2 available position comparisons produce an average error of 88 nautical miles.

At the lead time of 3 days (72 hours), there were 4 hits, 0 false detections and 4 misses. 4 available position comparisons produce an average error of 152 nautical miles.

At the lead time of 4 days (96 hours), there were 5 hits, 0 false detections and 6 misses. 5 available position comparisons produce an average error of 154 nautical miles.

At the lead time of 5 days (120 hours), there were 6 hits, 4 false detections and 8 misses. 8 available position comparisons produce an average error of 214 nautical miles.

At the lead time of 6 days (144 hours), there were 3 hits, 12 false detections and 12 misses. 10 available position comparisons produce an average error of 241 nautical miles.

At the lead time of 7 days (168 hours), there were 5 hits, 19 false detections and 10 misses. 13 available position comparisons produce an average error of 346 nautical miles.

At the lead time of 8 days (192 hours), there were 5 hits, 19 false detections and 9 misses. 12 available position comparisons produce an average error of 313 nautical miles.

At the lead time of 9 days (216 hours), there were 4 hits, 18 false detections and 10 misses. 11 available position comparisons produce an average error of 296 nautical miles.

At the lead time of 10 days (240 hours), there were 5 hits, 25 false detections and 9 misses. 11 available position comparisons produce an average error of 278 nautical miles.

At the lead time of 11 days (264 hours), there were 3 hits, 31 false detections and 11 misses. 14 available position comparisons produce an average error of 373 nautical miles.

At the lead time of 12 days (288 hours), there were 3 hits, 20 false detections and 13 misses. 13 available position comparisons produce an average error of 394 nautical miles.

At the lead time of 13 days (312 hours), there were 2 hits, 18 false detections and 14 misses. 12 available position comparisons produce an average error of 524 nautical miles.

At the lead time of 14 days (336 hours), there were 0 hits, 12 false detections and 14 misses. 7 available position comparisons produce an average error of 357 nautical miles.

At the lead time of 15 days (360 hours), there were 2 hits, 11 false detections and 13 misses. 6 available position comparisons produce an average error of 562 nautical miles.

At the lead time of 16 days (384 hours), there were 1 hits, 12 false detections and 15 misses. 3 available position comparisons produce an average error of 581 nautical miles.

Here are the tracks once again.

April 26, 06Z run: