MEI Ranks (last update: 5 August 2014)

Bimonthly ranks of the MEI, since the beginning of record in Dec1949/Jan1950. If two MEI values are
identical within the same bimonthly season, their rank is split between them, leading to a ".5" value. 
Missing values are left blank.  

How can one interpret these ranks?  Given that there are 64-65 numbers in each column, the lowest
number (1) would denote the strongest La Nina case for that bimonthly season, while the highest
number (64 or 65) would indicate the strongest El Nino case.  For instance, in December-January 
(DECJAN), the strongest La Nina was recorded in 1974, while the strongest El Nino occurred in 1983.

If we use percentiles (say, 30%ile) to define La Nina, near-normal, and El Nino, MEI ranks from 1-19
denote strong to weak La Nina conditions, while 46-64 (47-65) denote weak to strong El Nino conditions.
If one uses the quintile definition for (moderate or stronger) ENSO events, MEI ranks from 1-13
would denote La Nina, while 52-64 (53-65) would denote El Nino.  Finally, the comparison figures on this
website refer to strong ENSO events, such as might be defined by the top 6 (one tenth or smaller)
ranks, such as 1-6 for La Nina, and 59-64 (60-65) for El Nino.

YEAR    DECJAN  JANFEB  FEBMAR  MARAPR  APRMAY  MAYJUN  JUNJUL  JULAUG  AUGSEP  SEPOCT  OCTNOV  NOVDEC
1950	12	11	6	8	4	5	5	10	18	21	11	7
1951	10	10	8	22	20	42	49	53	51	48	47	44
1952	45	38	37.5	39	21.5	13	22	29	40	41	25	33
1953	37	44	45	57	56	37	40	38	46	35	36	39
1954	36	37	43	19	3	2	4	5	11	7	12	10
1955	15	19	10	3	1	1	1	1	3	3	1	2
1956	4	7	5	6	5	3	7	9	7	5	15	12
1957	14	27	41	45	57	48	54	58.5	59	58	56	58
1958	61	60	60	60	52	53	48	42	34	39	42	49
1959	47	52	50	37	29	32	25	33	32	29	27	29
1960	30	31	32	31.5	19	21	20	24	22	24	26	24
1961	34	30	31	31.5	21.5	27	26	25	26	19	21	18
1962	9	12	17	9.5	9	8	13	15	19	18	19	23
1963	17	14	18	15	13.5	29	42	45	49	49	51	50
1964	53	46	23	17	6	7	3	4	8	9	8	16
1965	24	28	27	34	46	56	60	60	60	59	61	60
1966	60	59	52	53	24	24	27	36	30	31	35	30
1967	27	13	11	7	15	18	14	20	16	17	22	25
1968	19	18	19	11	7	10	15	31	36	42	44	41
1969	49	53	48	55	50	49	41	35	33	44	46	42
1970	44	45	44	27	26	11	10	11	9	11	13	6
1971	5	3	1	1	2	4	6	8	6	6	6	13
1972	20	26	26	23	43	60	64	62	61	62	62	62
1973	62	61	54	50	27	9	11	7	4	4	4	1
1974	1	1	2	2	8	14	12	13	17	12	7	15
1975	21	21	14	12	10	6	2	3	2	1	2	3
1976	3	5	7	5	13.5	39	46	47	57	51	41	45
1977	46	40	39	52	39	44	53	49	54	54	53	51
1978	52	54	57	36	17	15	19	28	24	30	38	43
1979	48	43	34	40	41	40	38	46	50	46	48	54
1980	50	49	51	59	58	50	50	40	39	38	39	36
1981	33	34	47	56	33	31	31	32	35	34	33	32
1982	32	36	37.5	29	42	57	61	61	62	63	63	64
1983	65	65	65	65	65	64	62	58.5	42	32	29	31
1984	28	24	40	43	34	25	29	27	31	33	24	19
1985	22	22	15	21	11	28	28	22	20	28	34	28
1986	31	33	35	24	38	38	39	52	58	53	52	57
1987	59	58	62	62	62	63	63	63	63	61	58	59
1988	55	50	49	41	31	12	9	6	5	8	5	5
1989	7	6	13	14	16	20	17	16	25	25	32	37
1990	39	48	56	46	49	41	34	34	41	40	40	40
1991	42	41	46	49	51	58	57	57	47	55	57	61
1992	63	63	63	63	63	62	56	43	44	47	45	48
1993	51	57	58	61	61	61	58	56	56	57	50	46
1994	43	39	42	48	47	47	52	50	55	60	59	56
1995	58	56	55	47	45	43	35	26	23	20	20	22
1996	18	23	24	20	25	33	23	21	21	22	30	26
1997	25	20	25	51	60	65	65	64	64	64	64	63
1998	64	64	64	64	64	59	37	19	14	15	10	11
1999	8	9	12	9.5	12	16	16	12	12	13	14	8
2000	6	8	9	18	35	26	24	30	27	23	17	21
2001	23	16	20	26	37	30	36	41	29	26	28	34
2002	35	32	28	44	55	52	45	54	53	52	54	55
2003	57	55	53	42	30	34	33	37	43	45	43	38
2004	41	42	30	38	44	36	43	48	45	43	49	47
2005	40	51	59	54	54	45	44	39	37	27	23	20
2006	26	25	21	16	28	46	47	51	52	50	60	52
2007	54	47	36	28	36	19	21	18	10	10	9	9
2008	13	4	3	13	18	35	32	23	15	16	18	17
2009	16	15	16	25	40	55	55	55	48	56	55	53
2010	56	62	61	58	48	17	8	2	1	2	3	4
2011	2	2	4	4	23	23	30	17	13	14	16	14
2012	11	17	22	33	53	54	59	44	38	37	37	35
2013	38	35	29	30	32	22	18	14	28	36	31	27
2014	29	29	33	35	59	51	51	

Next update: 6 September 2014 (probably earlier)

Link to numerical MEI values is here.

Go back to MEI homepage.