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Showing posts from December, 2019

Verification of tracks made of TD 21E using GEFS mean fields

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I made six tracks of Tropical Depression Twenty-One-E. Additionally, within 384 hours of cyclogenesis, there were twelve instances, when I missed cyclogenesis entirely. Formation time was often late, while dissipation time was even more late. As of this analysis, best track positions are available November 14, 12Z thru November 18, 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 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 November 15, 06Z and November 24, 06Z. Average was November 19, 09Z and median was November 18, 12Z.  In the eighteen cases (6 tracks and 12 complete misses)

Verification of tracks made of Raymond using GEFS mean fields

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I made eight tracks of Tropical Storm Raymond. Additionally, within 384 hours of cyclogenesis, there were nine instances, when I missed cyclogenesis entirely. Detection rate was good, and so were formation time and position accuracy. Dissipation time was typically too late. As of this analysis, best track positions are available November 13, 06Z thru November 17, 12Z, 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 eight tracks, formation times ranged between November 13, 06Z and November 18, 00Z. Average was November 15, 05Z and median was November 15, 00Z.  In the seventeen cases (8 track

Verification of tracks made of Akoni using GEFS mean fields

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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

Verification of Atlantic ghost storm tracks of August-October 2019

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I falsely detected (sub)tropical cyclogenesis in Atlantic (north of equator and west of Greenwich) 56 times in August thru October of 2019. Tracks were made of 23 systems. At the lead time of 1 day ( 24 hours), there were 0 false detections. At the lead time of 2 days ( 48 hours), there were 0 false detections. At the lead time of 3 days ( 72 hours), there were 3 false detections. At the lead time of 4 days ( 96 hours), there were 4 false detections. At the lead time of 5 days ( 120 hours), there were 5 false detections. At the lead time of 6 days ( 144 hours), there were 7 false detections. At the lead time of 7 days ( 168 hours), there were 10 false detections. At the lead time of 8 days ( 192 hours), there were 11 false detections. At the lead time of 9 days ( 216 hours), there were 13 false detections. At the lead time of 10 days ( 240 hours), there were 17 false detections. At the lead time of 11 days ( 264 hours), there were 23 false