Verification of tracks made of Sandra

I made eight tracks of Tropical Storm Sandra, before it was assessed as a tropical cyclone. I made one more track after cyclogenesis. Additionally, within 504 hours of cyclogenesis, there was one instance, when I missed cyclogenesis entirely.

As of this analysis, best track positions are available November 3, 18Z thru November 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 subtropical depressions as "Category -1" and non-existence of a tropical or subtropical cyclone as "Category -2".

In the eight tracks (made before operationally recognized cyclogenesis), formation times ranged between November 2, 12Z and November 6, 06Z. Average was November 4, 17Z and median was November 5, 03Z.

In the nine cases (8 tracks, before the tracks and data agreed, that tropical storm would remain the peak intensity, and 1 complete miss), peak intensity ranged between Category -2 and Category 5. Average was Category 0.11 and median was Category 0.

In the nine tracks (made before operationally recognized degeneration), dissipation times ranged between November 3, 00Z and November 13, 00Z. Average was November 8, 13Z and median was November 9, 06Z.

At the lead time of 1 day (24 hours), there were 1 hit, 0 false detections and 0 misses. 1 available position comparison produces an average error of 30 nautical miles.

At the lead time of 2 days (48 hours), there were 0 hits, 0 false detections and 0 misses. No available position comparisons.

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 133 nautical miles.

At the lead time of 4 days (96 hours), there were 1 hit, 1 false detection and 0 misses. 2 available position comparisons produce an average error of 78 nautical miles.

At the lead time of 5 days (120 hours), there were 1 hit, 1 false detection and 0 misses. 2 available position comparisons produce an average error of 156 nautical miles.

At the lead time of 6 days (144 hours), there were 1 hit, 2 false detections and 0 misses. 3 available position comparisons produce an average error of 392 nautical miles.

At the lead time of 7 days (168 hours), there were 1 hit, 1 false detection and 0 misses. 2 available position comparisons produce an average error of 395 nautical miles.

At the lead time of 8 days (192 hours), there were 0 hits, 2 false detections and 0 misses. 2 available position comparisons produce an average error of 405 nautical miles.

At the lead time of 9 days (216 hours), there were 1 hit, 2 false detections and 0 misses. 2 available position comparisons produce an average error of 347 nautical miles.

At the lead time of 10 days (240 hours), there were 1 hit, 2 false detections and 0 misses. 2 available position comparisons produce an average error of 348 nautical miles.

At the lead time of 11 days (264 hours), there were 0 hits, 3 false detections and 0 misses. 2 available position comparisons produce an average error of 247 nautical miles.

At the lead time of 12 days (288 hours), there were 1 hit, 1 false detection and 0 misses. 2 available position comparisons produce an average error of 314 nautical miles.

At the lead time of 13 days (312 hours), there were 0 hits, 0 false detection and 1 miss. No available position comparisons.

At the lead time of 14 days (336 hours), there were 0 hits, 1 false detection and 1 miss. No available position comparisons.

At the lead time of 15 days (360 hours), there were 0 hits, 2 false detections and 1 miss. 2 available position comparisons produce an average error of 337 nautical miles.

At the lead time of 16 days (384 hours), there were 0 hits, 3 false detections and 0 misses. 2 available position comparisons produce an average error of 470 nautical miles.

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

At the lead time of 18 days (432 hours), there were 0 hits, 0 false detection and 1 miss. No available position comparisons.

At the lead time of 19 days (456 hours), there were 0 hits, 0 false detection and 2 misses. No available position comparisons.

At the lead time of 20 days (480 hours), there were 0 hits, 0 false detection and 2 misses. No available position comparisons.

At the lead time of 21 days (504 hours), there were 0 hits, 0 false detection and 1 miss. No available position comparisons.

Circle coloration scheme

Here are the tracks once again.

October 17, 12Z:

October 20, 12Z:

October 21, 12Z:

October 25, 06Z:

October 27, 12Z:

October 30, 06Z:

November 1, 18Z:

November 3, 18Z:

November 8, 12Z:

The complete miss was from the following model cycle:

October 18, 18Z