Verification of tracks made on Debby using GEFS mean fields
I made 29 tracks about Tropical Storm Debby. Additionally, within 384 hours of cyclogenesis, there were 9 instances, when I missed cyclogenesis entirely. Timing of the existence of Debby was originally too early, and position was way too east. Intensity projections varied in both long and short range.
As of this analysis, best track positions are available August 2, 18Z thru August 9, 18Z, 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 29 tracks, formation times ranged between July 29, 18Z and August 9, 06Z. Average was August 5, 17Z and median was August 5, 12Z.
In the 38 cases (29 tracks and 9 complete misses), peak intensity ranged between Category -2 and Category 2. Average was Category -0.26 and median was Category 0.
In the 29 tracks, dissipation times ranged between August 4, 00Z and August 17, 18Z. Average was August 9, 00Z and median was August 9, 00Z.
At the lead time of 1 day (24 hours), there were 4 hits, 0 false detections and 0 misses. 4 available position comparisons produce an average error of 112 nautical miles.
At the lead time of 2 days (48 hours), there were 4 hits, 0 false detections and 4 misses. 4 available position comparisons produce an average error of 133 nautical miles.
At the lead time of 3 days (72 hours), there were 1 hits, 0 false detections and 9 misses. 1 available position comparison produces an average error of 92 nautical miles.
At the lead time of 4 days (96 hours), there were 2 hits, 1 false detections and 5 misses. 2 available position comparisons produce an average error of 168 nautical miles.
At the lead time of 5 days (120 hours), there were 1 hits, 1 false detections and 6 misses. 2 available position comparisons produce an average error of 67 nautical miles.
At the lead time of 6 days (144 hours), there were 3 hits, 1 false detections and 4 misses. 3 available position comparisons produce an average error of 309 nautical miles.
At the lead time of 7 days (168 hours), there were 5 hits, 3 false detections and 0 misses. 6 available position comparisons produce an average error of 391 nautical miles.
At the lead time of 8 days (192 hours), there were 1 hits, 6 false detections and 0 misses. 2 available position comparisons produce an average error of 443 nautical miles.
At the lead time of 9 days (216 hours), there were 0 hits, 7 false detections and 0 misses. No available position comparisons.
At the lead time of 10 days (240 hours), there were 0 hits, 4 false detections and 0 misses. No available position comparisons.
At the lead time of 11 days (264 hours), there were 0 hits, 7 false detections and 0 misses. 4 available position comparisons produce an average error of 678 nautical miles.
At the lead time of 12 days (288 hours), there were 0 hits, 11 false detections and 0 misses. 7 available position comparisons produce an average error of 819 nautical miles.
At the lead time of 13 days (312 hours), there were 0 hits, 7 false detections and 0 misses. 3 available position comparisons produce an average error of 826 nautical miles.
At the lead time of 14 days (336 hours), there were 0 hits, 4 false detections and 4 misses. 2 available position comparisons produce an average error of 628 nautical miles.
At the lead time of 15 days (360 hours), there were 0 hits, 4 false detections and 8 misses. 2 available position comparisons produce an average error of 774 nautical miles.
At the lead time of 16 days (384 hours), there were 0 hits, 5 false detections and 10 misses. 4 available position comparisons produce an average error of 556 nautical miles.
Here are the tracks once again.
July 17, 18Z run:
July 18, 06Z run:
July 18, 12Z run:
July 19, 12Z run:
July 19, 18Z run:
July 20, 00Z run:
July 22, 06Z run:
July 22, 12Z run:
July 23, 06Z run:
July 23, 18Z run:
July 24, 00Z run:
July 24, 06Z run:
July 24, 12Z run:
July 24, 18Z run:
July 25, 00Z run:
August 1, 12Z run:
August 1, 18Z run:
August 2, 00Z run:
August 2, 06Z run:
August 2, 12Z run:
August 2, 18Z run:
August 3, 00Z run:
August 4, 00Z run:
August 4, 18Z run:
August 5, 00Z run:
August 6, 06Z run:
August 6, 12Z run:
August 6, 18Z run:
August 7, 06Z run:
The complete misses were from following runs:
July 22, 18Z
July 23, 00Z
July 23, 12Z
August 4, 06Z
August 4, 12Z
August 5, 06Z
August 5, 12Z
August 5, 18Z
August 6, 00Z
As of this analysis, best track positions are available August 2, 18Z thru August 9, 18Z, 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 29 tracks, formation times ranged between July 29, 18Z and August 9, 06Z. Average was August 5, 17Z and median was August 5, 12Z.
In the 38 cases (29 tracks and 9 complete misses), peak intensity ranged between Category -2 and Category 2. Average was Category -0.26 and median was Category 0.
In the 29 tracks, dissipation times ranged between August 4, 00Z and August 17, 18Z. Average was August 9, 00Z and median was August 9, 00Z.
At the lead time of 1 day (24 hours), there were 4 hits, 0 false detections and 0 misses. 4 available position comparisons produce an average error of 112 nautical miles.
At the lead time of 2 days (48 hours), there were 4 hits, 0 false detections and 4 misses. 4 available position comparisons produce an average error of 133 nautical miles.
At the lead time of 3 days (72 hours), there were 1 hits, 0 false detections and 9 misses. 1 available position comparison produces an average error of 92 nautical miles.
At the lead time of 4 days (96 hours), there were 2 hits, 1 false detections and 5 misses. 2 available position comparisons produce an average error of 168 nautical miles.
At the lead time of 5 days (120 hours), there were 1 hits, 1 false detections and 6 misses. 2 available position comparisons produce an average error of 67 nautical miles.
At the lead time of 6 days (144 hours), there were 3 hits, 1 false detections and 4 misses. 3 available position comparisons produce an average error of 309 nautical miles.
At the lead time of 7 days (168 hours), there were 5 hits, 3 false detections and 0 misses. 6 available position comparisons produce an average error of 391 nautical miles.
At the lead time of 8 days (192 hours), there were 1 hits, 6 false detections and 0 misses. 2 available position comparisons produce an average error of 443 nautical miles.
At the lead time of 9 days (216 hours), there were 0 hits, 7 false detections and 0 misses. No available position comparisons.
At the lead time of 10 days (240 hours), there were 0 hits, 4 false detections and 0 misses. No available position comparisons.
At the lead time of 11 days (264 hours), there were 0 hits, 7 false detections and 0 misses. 4 available position comparisons produce an average error of 678 nautical miles.
At the lead time of 12 days (288 hours), there were 0 hits, 11 false detections and 0 misses. 7 available position comparisons produce an average error of 819 nautical miles.
At the lead time of 13 days (312 hours), there were 0 hits, 7 false detections and 0 misses. 3 available position comparisons produce an average error of 826 nautical miles.
At the lead time of 14 days (336 hours), there were 0 hits, 4 false detections and 4 misses. 2 available position comparisons produce an average error of 628 nautical miles.
At the lead time of 15 days (360 hours), there were 0 hits, 4 false detections and 8 misses. 2 available position comparisons produce an average error of 774 nautical miles.
At the lead time of 16 days (384 hours), there were 0 hits, 5 false detections and 10 misses. 4 available position comparisons produce an average error of 556 nautical miles.
Here are the tracks once again.
July 17, 18Z run:
August 2, 12Z run:
August 2, 18Z run:
The complete misses were from following runs:
July 22, 18Z
July 23, 00Z
July 23, 12Z
August 4, 06Z
August 4, 12Z
August 5, 06Z
August 5, 12Z
August 5, 18Z
August 6, 00Z
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