Template:Tropical cyclone numbering

Tropical Cyclone Numbering[1][2][3]
Basin(s) Warning
Center
Format Example
N Atlantic NHC nn
(nnL)​[a]
06
(06L)
NE Pacific
(E of 140°W)
nnE 09E
NC Pacific
(E of IDL, W of 140°W)
CPHC nnC 02C
NW Pacific
(W of IDL)
JMA yynn
(nn, Tyynn)​[b]
1330
(30, T1330)
JTWC nnW 10W
N Indian
(Bay of Bengal)
IMD BOB nn BOB 03
JTWC nnB 05B
N Indian
(Arabian Sea)
IMD ARB nn ARB 01
JTWC nnA 02A
Mediterranean SAB nnM 90M
SW Indian
(W of 90°E)
MFR nn
(REnn)​[c]
07
(RE07)
SW Indian & Australian reg.
(W of 135°E)
JTWC nnS 01S
Australian reg.
(E of 90°E, W of 160°E)
BOM nnU 08U
Australian reg. & S Pacific
(E of 135°E)
JTWC nnP 04P
S Pacific
(E of 160°E)
FMS nnF 11F
S Atlantic NRL, NHC[d] nnQ 01Q
UKMet nnT[e] 02T
Notes:
  1. ^ Although the NHC does not append any suffix to TC numbers of North Atlantic-basin cyclones, the ATCF-defined suffix L is explicitly appended to them by JTWC and non-US-based weather services like UKMet, to avoid ambiguity with numbers from other warning centers tracking other basins. (The L suffix is explicitly used, however, by NHC for other non-cyclonic systems in N Atlantic, like invests.)
  2. ^ yy indicates the last two digits of a year and is often omitted for non-English usages. The prefix T is only used for the best track data and technical reports by JMA.[4][5]
  3. ^ MFR assigns prefix RE only for its best track data pages.[6] Historically, weather website Australia Severe Weather added prefix MFR- to MFR-tracked cyclone numbers (like "MFR-07") to distinguish them from JTWC numbers;[7] this practice is no longer done.
  4. ^ Although the NHC does not issue warnings for the South Atlantic basin, it has tracked tropical systems there in the past, in coordination with the NRL's Marine Meteorological Division.[8]
  5. ^ Although UKMet does not issue warnings for the South Atlantic basin, it does assign suffix T to it since 2004, but only for cyclones without US track data.[7][9]