Tropical Cyclone Serial Number
SummaryTo develop a storm identifier that is unlikely to change as storms are added or observations are changed.
PurposeStorms are identified differently in each basin and by each RSMC. Many are named, but naming is not consistent between all countries, nor is it helpful for historic storms. Also, numbering can be tricky given the potential for changes to storm numbers (new storms added, a storm removed, etc.). Thus it is desirable to have a storm serial number which is unlikely to change during the lifetime of a storm.
Serial Number FormatThe approach was to select storm characteristics which are most likely to be agreed upon between operational centers and least likely to change upon reanalysis. The format we chose is based on the first recorded observation of the storm:
- YYYY is the corresponding year of the first recorded observation of the storm
- JJJ is the day of year of the first recorded observation of the storm
- H is the hemisphere of the storm: N=Northern, S=Southern
- TT is the absolute value of the rounded latitude of the first recorded observation of the storm (range 0-90, if basin=SA or SH, then TT in reality is negative)
- NNN is the rounded longitude of the first recorded observation of the storm (range 0-359)
1970138N12281is a storm in the North Atlantic which started on May 18, 1970 near 12°N 281°E (79°W).
We chose to keep a serial number which will have a constant length, so the storm name is not included in the serial number.