Verification of tracks made on Franklin (2017) using GEFS mean fields
I made 22 tracks about Hurricane Franklin. In five additional cases,
while trying to generate tracks, I missed the system entirely. Intensity
forecast was much better than in the case of TD 4. Position forecast was also good to very large lead times.
My analysis begins at August 1, 12Z, which is the earliest time, at which one of my tracks had cyclogenesis. Analysis ends at August 10, 12Z, since any continuation of Franklin's remnants into the Pacific and the possibility of regeneration there was not meant to be considered.
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 storms as "Category 0", tropical depressions as "Category -1" and non-existence of a tropical cyclone as "Category -2".
I compare intensities only in cases, when either the best track data or my track has a tropical cyclone, or both. In other words, I leave the comparison out of calculations, if both best track data and
my track lack a tropical cyclone.
In the 22 tracks, formation times ranged between August 1, 12Z and August 11, 12Z. Median was August 8, 00Z and average was August 7, 10Z.
The 27 peak intensities (complete misses included) ranged between non-formation (Category -2) to Category 4. Median was Category 1 and average was Category 0.6.
Dissipation times ranged between August 6, 00Z and August 14, 12Z. Median was August 12, 03Z and average was August 11, 09Z.
The following lines will have the format:
date and time (UTC) yyyy/mm/dd/hh ... number of true detections ... number of misses ... number of false detections ... number of position comparisons ... number of intensity comparisons ... average error in intensity category ... bias in intensity category ... average error in latitude ... bias in latitude ... average error in longitude ... bias in longitude ... upper limit for scalar error in position (nautical miles)... calculated scalar bias in position (nautical miles)
actual cyclogenesis:
2017/08/07/00 ... 7 ... 20 ... 0 ... 7 ... 27 ... 1.7 ... -1.3 ... 4.3 ... 4.3N ... 2.4 ... 2.3W ... 540 ... 540
reaching hurricane intensity:
2017/08/09/18 ... 14 ... 13 ... 0 ... 14 ... 27 ... 2.2 ... -2.0 ... 3.3 ... 2.5N ... 2.8 ... 1.5E ... 250 ... 170
landfall:
2017/08/10/06 ... 13 ... 14 ... 0 ... 13 ... 27 ... 2.2 ... -2.0 ... 2.6 ... 2.5N ... 3.0 ... 2.8E ... 230 ... 220
And for lead times:
168h ... 5 ... 8 ... 0 ... 5 ... 13 ... 1.7 ... -1.2 ... 2.9 ... 0.4N ... 4.3 ... 2.5E ... 300 ... 140
192h ... 3 ... 4 ... 3 ... 5 ... 10 ... 1.6 ... -0.4 ... 2.0 ... 0.1N ... 3.4 ... 1.6E ... 230 ... 90
216h ... 1 ... 3 ... 4 ... 5 ... 8 ... 2.0 ... +-0 ... 4.0 ... 4.0N ... 4.2 ... 3.9W ... 340 ... 330
240h ... 1 ... 0 ... 4 ... 5 ... 5 ... 2.6 ... +2.6 ... 4.3 ... 4.3N ... 3.8 ... 2.0W ... 340 ... 280
264h ... 1 ... 2 ... 3 ... 4 ... 6 ... 2.5 ... +1.2 ... 4.8 ... 4.8N ... 2.8 ... 2.8W ... 330 ... 330
288h ... 2 ... 5 ... 5 ... 7 ... 12 ... 1.6 ... -0.1 ... 3.7 ... 3.7N ... 3.0 ... 3.0W ... 280 ... 280
312h ... 6 ... 7 ... 3 ... 10 ... 14 ... 1.4 ... +-0 ... 3.0 ... 3.0N ... 4.3 ... 4.0W ... 300 ... 290
336h ... 7 ... 8 ... 0 ... 7 ... 15 ... 1.7 ... -0.7 ... 3.7 ... 2.8N ... 2.7 ... 0.5W ... 260 ... 210
360h ... 6 ... 5 ... 0 ... 6 ... 11 ... 1.4 ... -1.2 ... 3.6 ... 3.4N ... 2.6 ... 0.4W ... 260 ... 210
384h ... 3 ... 4 ... 0 ... 3 ... 7 ... 1.4 ... -1.1 ... 4.1 ... 4.1N ... 1.2 ... 0.2E ... 260 ... 250
408h ... 1 ... 2 ... 0 ... 1 ... 3 ... 2.0 ... -1.3 ... 10.2 ... 10.2N ... 5.3 ... 5.3E ... 680 ... 680
Here are the tracks.
July 24, 00Z run:
July 24, 06Z run:
July 24, 12Z run:
July 24, 18Z run:
July 25, 00Z run:
July 25, 06Z run:
July 25, 12Z run:
July 25, 18Z run:
July 26, 00Z run:
July 26, 06Z run:
July 26, 18Z run:
https://uploads.disquscdn.c...
July 27, 06Z run:
July 31, 12Z run:
https://uploads.disquscdn.c...
August 1, 06Z 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 3, 06Z run:
August 3, 12Z run:
Depending on situation, the system was considered "Emily", "Franklin" or "Gert".
The runs in which I missed the system entirely:
July 26, 12Z
July 27, 00Z
July 27, 12Z
July 31, 18Z
August 1, 00Z
My analysis begins at August 1, 12Z, which is the earliest time, at which one of my tracks had cyclogenesis. Analysis ends at August 10, 12Z, since any continuation of Franklin's remnants into the Pacific and the possibility of regeneration there was not meant to be considered.
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 storms as "Category 0", tropical depressions as "Category -1" and non-existence of a tropical cyclone as "Category -2".
I compare intensities only in cases, when either the best track data or my track has a tropical cyclone, or both. In other words, I leave the comparison out of calculations, if both best track data and
my track lack a tropical cyclone.
In the 22 tracks, formation times ranged between August 1, 12Z and August 11, 12Z. Median was August 8, 00Z and average was August 7, 10Z.
The 27 peak intensities (complete misses included) ranged between non-formation (Category -2) to Category 4. Median was Category 1 and average was Category 0.6.
Dissipation times ranged between August 6, 00Z and August 14, 12Z. Median was August 12, 03Z and average was August 11, 09Z.
The following lines will have the format:
date and time (UTC) yyyy/mm/dd/hh ... number of true detections ... number of misses ... number of false detections ... number of position comparisons ... number of intensity comparisons ... average error in intensity category ... bias in intensity category ... average error in latitude ... bias in latitude ... average error in longitude ... bias in longitude ... upper limit for scalar error in position (nautical miles)... calculated scalar bias in position (nautical miles)
actual cyclogenesis:
2017/08/07/00 ... 7 ... 20 ... 0 ... 7 ... 27 ... 1.7 ... -1.3 ... 4.3 ... 4.3N ... 2.4 ... 2.3W ... 540 ... 540
reaching hurricane intensity:
2017/08/09/18 ... 14 ... 13 ... 0 ... 14 ... 27 ... 2.2 ... -2.0 ... 3.3 ... 2.5N ... 2.8 ... 1.5E ... 250 ... 170
landfall:
2017/08/10/06 ... 13 ... 14 ... 0 ... 13 ... 27 ... 2.2 ... -2.0 ... 2.6 ... 2.5N ... 3.0 ... 2.8E ... 230 ... 220
And for lead times:
168h ... 5 ... 8 ... 0 ... 5 ... 13 ... 1.7 ... -1.2 ... 2.9 ... 0.4N ... 4.3 ... 2.5E ... 300 ... 140
192h ... 3 ... 4 ... 3 ... 5 ... 10 ... 1.6 ... -0.4 ... 2.0 ... 0.1N ... 3.4 ... 1.6E ... 230 ... 90
216h ... 1 ... 3 ... 4 ... 5 ... 8 ... 2.0 ... +-0 ... 4.0 ... 4.0N ... 4.2 ... 3.9W ... 340 ... 330
240h ... 1 ... 0 ... 4 ... 5 ... 5 ... 2.6 ... +2.6 ... 4.3 ... 4.3N ... 3.8 ... 2.0W ... 340 ... 280
264h ... 1 ... 2 ... 3 ... 4 ... 6 ... 2.5 ... +1.2 ... 4.8 ... 4.8N ... 2.8 ... 2.8W ... 330 ... 330
288h ... 2 ... 5 ... 5 ... 7 ... 12 ... 1.6 ... -0.1 ... 3.7 ... 3.7N ... 3.0 ... 3.0W ... 280 ... 280
312h ... 6 ... 7 ... 3 ... 10 ... 14 ... 1.4 ... +-0 ... 3.0 ... 3.0N ... 4.3 ... 4.0W ... 300 ... 290
336h ... 7 ... 8 ... 0 ... 7 ... 15 ... 1.7 ... -0.7 ... 3.7 ... 2.8N ... 2.7 ... 0.5W ... 260 ... 210
360h ... 6 ... 5 ... 0 ... 6 ... 11 ... 1.4 ... -1.2 ... 3.6 ... 3.4N ... 2.6 ... 0.4W ... 260 ... 210
384h ... 3 ... 4 ... 0 ... 3 ... 7 ... 1.4 ... -1.1 ... 4.1 ... 4.1N ... 1.2 ... 0.2E ... 260 ... 250
408h ... 1 ... 2 ... 0 ... 1 ... 3 ... 2.0 ... -1.3 ... 10.2 ... 10.2N ... 5.3 ... 5.3E ... 680 ... 680
Here are the tracks.
July 24, 00Z run:
https://uploads.disquscdn.c...
July 27, 06Z run:
https://uploads.disquscdn.c...
August 1, 06Z run:
Depending on situation, the system was considered "Emily", "Franklin" or "Gert".
The runs in which I missed the system entirely:
July 26, 12Z
July 27, 00Z
July 27, 12Z
July 31, 18Z
August 1, 00Z
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