Verification of a track made of Octave using GEFS mean fields

This was originally posted on November 17, 2019. This was corrected on January 10, 2020, as I found, that I had actually done one track of Octave. Previously I thought, that I had done none.

I made one track of Tropical Storm Octave. Within 384 hours of cyclogenesis, there were ten instances, where I missed cyclogenesis.

As of this analysis, best track positions are available October 16, 12Z thru October 19, 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 track, range, average and median of formation time was October 17, 18Z.

In the eleven cases (1 track and 10 complete misses), peak intensity ranged between Category -2 and Category 2. Average was Category -1.64 and median was Category -2.

In the track, range, average and median of dissipation time was October 31, 00Z.


At the lead time of 1 day (24 hours), there were 0 hits, 0 false detections and 1 miss. No available position comparisons.

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

At the lead time of 3 days (72 hours), there were 1 hit, 0 false detections and 1 miss. 1 available position comparison produces an average error of 72 nautical miles.

At the lead time of 4 days (96 hours), there were 1 hit, 0 false detections and 1 miss. 1 available position comparison produces an average error of 141 nautical miles.

At the lead time of 5 days (120 hours), there were 0 hits, 1 false detection and 2 misses. 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, 1 false detection and 1 miss. No available position comparisons.

At the lead time of 9 days (216 hours), there were 0 hits, 1 false detection and 1 miss. No available position comparisons.

At the lead time of 10 days (240 hours), there were 0 hits, 1 false detection and 1 miss. 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, 1 false detection and 1 miss. No available position comparisons.

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

At the lead time of 16 days (384 hours), there were 0 hits, 0 false detections and 2 misses. No available position comparisons.

Circle coloration scheme

Here is the track once again.

October 15, 12Z run:

The GEFS runs with complete misses were:

October 2, 06Z
October 3, 06Z
October 5, 06Z
October 7, 06Z
October 9, 06Z

October 11, 06Z
October 13, 06Z
October 14, 12Z
October 16, 06Z
October 17, 06Z