Verification of tracks made of Akoni using GEFS mean fields
I made six tracks of Tropical Storm Akoni. Additionally, within
384
hours of cyclogenesis, there were nine instances, when I missed
cyclogenesis entirely. All the detections were at long lead times. Cyclogenesis was generally way too close to equator and too early, and positions at all times too far southwest.
Exiting the EPac tracking map through its left edge is considered equal to dissipation for the purpose of this verification.
As of this analysis, Tropical Cyclone Report positions are available September 3, 06Z thru September 6, 12Z, and as such, position comparisons are possible only for this timespan. It should be noted, that while best track showed cyclogenesis to be west of 140W, post-season analysis showed cyclogenesis exactly at 140.0W, allowing me to consider Akoni to be a EPac cyclogenesis (otherwise, my tracks should be considered ghost storms)
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 six tracks, formation times ranged between August 27, 12Z and September 1, 06Z. Average was August 30, 16Z and median was August 31, 00Z.
In the fifteen cases (6 tracks and 9 complete misses), peak intensity ranged between Category -2 and Category 5. Average was Category -0.33 and median was Category -2.
In the six tracks, dissipation times ranged between September 2, 12Z and September 13, 12Z. Average was September 7, 15Z and median was September 7, 09Z.
At the lead time of 1 day (24 hours), there were 0 hits, 1 false detection and 1 miss. No available position comparisons.
At the lead time of 2 days (48 hours), there were 0 hits, 1 false detection and 1 miss. No available position comparisons.
At the lead time of 3 days (72 hours), there were 0 hits, 1 false detection and 1 miss. No available position comparisons.
At the lead time of 4 days (96 hours), there were 0 hits, 1 false detection and 1 miss. No available position comparisons.
At the lead time of 5 days (120 hours), there were 0 hits, 1 false detection and 1 miss. No available position comparisons.
At the lead time of 6 days (144 hours), there were 0 hits, 1 false detection and 1 miss. No available position comparisons.
At the lead time of 7 days (168 hours), there were 0 hits, 1 false detection and 1 miss. No available position comparisons.
At the lead time of 8 days (192 hours), there were 0 hits, 0 false detections and 2 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, 1 false detection and 1 miss. No available position comparisons.
At the lead time of 12 days (288 hours), there were 0 hits, 3 false detections and 1 miss. No available position comparisons.
At the lead time of 13 days (312 hours), there were 0 hits, 4 false detections and 2 misses. 1 available position comparison produces an average error of 684 nautical miles.
At the lead time of 14 days (336 hours), there were 0 hits, 4 false detections and 2 misses. 2 available position comparisons produce an average error of 676 nautical miles.
At the lead time of 15 days (360 hours), there were 1 hit, 4 false detections and 0 misses. 3 available position comparisons produce an average error of 724 nautical miles.
At the lead time of 16 days (384 hours), there were 3 hits, 2 false detections and 0 misses. 4 available position comparisons produce an average error of 743 nautical miles.
Circle coloration scheme
Here are the tracks once again.
August 16, 06Z run:
August 18, 12Z run:
August 19, 12Z run:
August 20, 06Z run:
August 21, 06Z run:
August 26, 12Z run:
The complete misses were from the following runs:
August 22, 12Z
August 23, 06Z
August 25, 06Z
August 27, 06Z
August 28, 06Z
August 29, 00Z
August 31, 00Z
September 2, 00Z
September 4, 00Z
Exiting the EPac tracking map through its left edge is considered equal to dissipation for the purpose of this verification.
As of this analysis, Tropical Cyclone Report positions are available September 3, 06Z thru September 6, 12Z, and as such, position comparisons are possible only for this timespan. It should be noted, that while best track showed cyclogenesis to be west of 140W, post-season analysis showed cyclogenesis exactly at 140.0W, allowing me to consider Akoni to be a EPac cyclogenesis (otherwise, my tracks should be considered ghost storms)
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 six tracks, formation times ranged between August 27, 12Z and September 1, 06Z. Average was August 30, 16Z and median was August 31, 00Z.
In the fifteen cases (6 tracks and 9 complete misses), peak intensity ranged between Category -2 and Category 5. Average was Category -0.33 and median was Category -2.
In the six tracks, dissipation times ranged between September 2, 12Z and September 13, 12Z. Average was September 7, 15Z and median was September 7, 09Z.
At the lead time of 1 day (24 hours), there were 0 hits, 1 false detection and 1 miss. No available position comparisons.
At the lead time of 2 days (48 hours), there were 0 hits, 1 false detection and 1 miss. No available position comparisons.
At the lead time of 3 days (72 hours), there were 0 hits, 1 false detection and 1 miss. No available position comparisons.
At the lead time of 4 days (96 hours), there were 0 hits, 1 false detection and 1 miss. No available position comparisons.
At the lead time of 5 days (120 hours), there were 0 hits, 1 false detection and 1 miss. No available position comparisons.
At the lead time of 6 days (144 hours), there were 0 hits, 1 false detection and 1 miss. No available position comparisons.
At the lead time of 7 days (168 hours), there were 0 hits, 1 false detection and 1 miss. No available position comparisons.
At the lead time of 8 days (192 hours), there were 0 hits, 0 false detections and 2 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, 1 false detection and 1 miss. No available position comparisons.
At the lead time of 12 days (288 hours), there were 0 hits, 3 false detections and 1 miss. No available position comparisons.
At the lead time of 13 days (312 hours), there were 0 hits, 4 false detections and 2 misses. 1 available position comparison produces an average error of 684 nautical miles.
At the lead time of 14 days (336 hours), there were 0 hits, 4 false detections and 2 misses. 2 available position comparisons produce an average error of 676 nautical miles.
At the lead time of 15 days (360 hours), there were 1 hit, 4 false detections and 0 misses. 3 available position comparisons produce an average error of 724 nautical miles.
At the lead time of 16 days (384 hours), there were 3 hits, 2 false detections and 0 misses. 4 available position comparisons produce an average error of 743 nautical miles.
Circle coloration scheme
Here are the tracks once again.
August 16, 06Z run:
August 18, 12Z run:
August 19, 12Z run:
August 20, 06Z run:
August 21, 06Z run:
August 26, 12Z run:
The complete misses were from the following runs:
August 22, 12Z
August 23, 06Z
August 25, 06Z
August 27, 06Z
August 28, 06Z
August 29, 00Z
August 31, 00Z
September 2, 00Z
September 4, 00Z
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