MEI Ranks (last update: 7 April 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	22	43	49	53	51	48	47	44
1952	45	38	37.5	38	23	14	22	29	40	41	25	33
1953	37	44	45	56	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	4	8	9	7	5	15	12
1957	14	27	41	44	57	48	55	58.5	59	58	56	58
1958	61	60	60	59	53	53	48	42	34	39	42	49
1959	47	52	50	37	29	33.5	25	33	32	29	27	29
1960	30	31	32	32	19.5	22	20	24	22	24	26	24
1961	34	30	31	31	21	29	26	25	26	19	21	18
1962	9	12	17	9	9	8	13	15	19	18	19	23
1963	17	14	18	15	16	30	43	45	49	49	51	50
1964	53	46	23	17	6	7	3	4	8	9	8	16
1965	24	28	27	34	47	56	59	60	60	59	61	60
1966	60	59	52	52	26	26	28	36	30	31	35	30
1967	27	13	11	7	15	18	14	20	16	17	22	25
1968	19	18	19	11	7	11	15	31	36	42	44	41
1969	49	53	48	54	51	49	41	35	33	44	46	42
1970	44	45	44	27	25	10	10	11	9	11	13	6
1971	5	3	1	1	2	3	6	8	6	6	6	13
1972	20	26	26	23	44	59	63	62	61	62	62	62
1973	62	61	54	49	27	9	11	7	4	4	4	1
1974	1	1	2	2	8	13	12	13	17	12	7	15
1975	21	21	14	12	10	6	2	3	2	1	2	3
1976	3	5	7	5	14	39	46	47	57	51	41	45
1977	46	40	39	51	39	45	52	49	54	54	53	51
1978	52	54	57	35	17	15	19	28	24	30	38	43
1979	48	43	34	39	41	40	38	46	50	46	48	54
1980	50	49	51	58	58	50	50	40	39	38	39	36
1981	33	34.5	47	55	33	31	31	32	35	34	33	32
1982	32	36	37.5	29	42	54	60	61	62	63	63	64
1983	65	65	65	64	64	63	61	58.5	42	32	29	31
1984	28	24	40	42	34	25	28	27	31	33	24	19
1985	22	22	15	21	11	27	28	22	20	28	34	28
1986	31	33	35	24	38	38	39	52	58	53	52	57
1987	59	58	62	61	61	62	62	63	63	61	58	59
1988	55	50	49	40	32	12	9	6	5	8	5	5
1989	7	6	13	14	13	21	18	16	25	25	32	37
1990	39	48	56	45	49	41	33.5	34	41	40	40	40
1991	42	41	46	48	52	58	56	57	47	55	57	61
1992	63	63	63	62	62	61	53.5	43	44	47	45	48
1993	51	57	58	60	60	60	57	56	56	57	50	46
1994	43	39	42	47	46	47	51	50	55	60	59	56
1995	58	56	55	46	45	42	35	26	23	20	20	22
1996	18	23	24	20	24	32	23	21	21	22	30	26
1997	25	20	25	50	59	64	64	64	64	64	64	63
1998	64	64	64	63	63	57	37	19	14	15	10	11
1999	8	9	12	10	12	17	16	12	12	13	14	8
2000	6	8	9	18	35	24	24	30	27	23	17	21
2001	23	16	20	26	37	28	36	41	29	26	28	34
2002	35	32	28	43	55	51	45	54	53	52	54	55
2003	57	55	53	41	30	33.5	33.5	37	43	45	43	38
2004	41	42	30	36	43	36	42	48	45	43	49	47
2005	40	51	59	53	54	44	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	53.5	55	48	56	55	53
2010	56	62	61	57	48	16	7	2	1	2	3	4
2011	2	2	4	4	19.5	23	30	17	13	14	16	14
2012	11	17	22	33	50	52	58	44	38	37	37	35
2013	38	34.5	29	30	31	20	17	14	28	36	31	27
2014	29	29	33
	
Next update: 10 May 2014 (probably earlier)

Link to numerical MEI values is here.

Go back to MEI homepage.