Verification of tracks made of Fred

I made no tracks of Tropical Storm Fred, before it was assessed as a tropical cyclone. I made two tracks after cyclogenesis. Within 504 hours of cyclogenesis, there were 15 instances, when I missed cyclogenesis entirely.

As of this analysis, best track positions are available August 7, 18Z thru August 20, 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".

Range, average and median of formation time are not applicable.

In the 16 cases (1 track, before the tracks and data agreed, that tropical storm would remain the peak intensity, and 15 complete misses), peak intensity ranged between Category -2 and  Category 1. Average was Category -1.81 and median was Category -2.

In the two tracks (made before operationally recognized final degeneration), dissipation time ranged between August 18, 00Z and August 19, 06Z. Average and median were August 18, 15Z.

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 61 nautical miles.

At the lead time of 2 days (48 hours), there were 1 hit, 0 false detections and 1 miss. 2 available position comparisons produce an average error of 74 nautical miles.

At the lead time of 3 days (72 hours), there were 0 hits, 1 false detection and 0 misses. 1 available position comparison produces an average error of 58 nautical miles.

At the lead time of 4 days (96 hours), there were 1 hit, 0 false detections and 1 miss. 1 available position comparison produces an average error of 159 nautical miles.

At the lead time of 5 days (120 hours), there were 1 hit, 0 false detections and 1 miss. 1 available position comparison produces an average error of 273 nautical miles.

At the lead time of 6 days (144 hours), there were 0 hits, 1 false detection and 1 miss. 1 available position comparison produces an average error of 395 nautical miles.

At the lead time of 7 days (168 hours), there were 0 hits, 1 false detection and 1 miss. 1 available position comparison produces an average error of 815 nautical miles.

At the lead time of 8 days (192 hours), there were 0 hits, 0 false detections and 3 misses. No available position comparisons.

At the lead time of 9 days (216 hours), there were 0 hits, 0 false detections and 3 misses. No available position comparisons.

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

At the lead time of 11 days (264 hours), there were 0 hits, 0 false detections and 2 misses. No available position comparisons.

At the lead time of 12 days (288 hours), there were 0 hits, 0 false detections and 4 misses. No available position comparisons.

At the lead time of 13 days (312 hours), there were 0 hits, 0 false detections and 4 misses. No available position comparisons.

At the lead time of 14 days (336 hours), there were 0 hits, 0 false detections and 4 misses. No available position comparisons.

At the lead time of 15 days (360 hours), there were 0 hits, 0 false detections and 4 misses. No available position comparisons.

At the lead time of 16 days (384 hours), there were 0 hits, 0 false detections and 4 misses. No available position comparisons.

At the lead time of 17 days (408 hours), there were 0 hits, 0 false detections and 5 misses. No available position comparisons.

At the lead time of 18 days (432 hours), there were 0 hits, 0 false detections and 6 misses. No available position comparisons.

At the lead time of 19 days (456 hours), there were 0 hits, 0 false detections and 7 misses. No available position comparisons.

At the lead time of 20 days (480 hours), there were 0 hits, 0 false detections and 7 misses. No available position comparisons.

At the lead time of 21 days (504 hours), there were 0 hits, 0 false detections and 7 misses. No available position comparisons.

Circle coloration scheme

Here are the tracks once again.

August 11, 18Z:

August 15, 12Z:

The complete misses were from the following model cycles:

July 21, 12Z
July 22, 18Z
July 23, 06Z
July 24, 00Z
July 24, 18Z

July 25, 12Z
July 26, 18Z
July 27, 12Z
July 27, 18Z
July 29, 12Z

July 30, 12Z
August 1, 18Z
August 3, 12Z
August 4, 12Z
August 7, 18Z