NetSTORM Point Precipitation Frequency Estimates

Annual Statistics | Event Listings | Frequency Estimates

Gage ID: 14739
Location: BOSTON, MA
Latitude: 42.3606°, Longitude: -71.0097°
Elevation: 12.1 ft
Additional metadata

Monthly Statistics
Month	Total	Records	Mean	Standard Deviation	Maximum	Duration
Jan	3.43	74.13	0.046	0.054	0.650	17.64
Feb	3.23	67.69	0.048	0.054	0.660	18.18
March	3.75	75.21	0.050	0.057	0.680	18.17
April	3.66	67.87	0.054	0.062	0.910	17.85
May	3.19	57.09	0.056	0.073	0.980	17.84
June	3.31	46.85	0.071	0.108	1.540	15.28
July	3.12	36.60	0.085	0.140	1.610	11.52
Aug	3.30	39.43	0.084	0.141	2.030	11.33
Sep	3.26	41.87	0.078	0.117	1.580	14.69
Oct	3.35	51.07	0.066	0.089	1.530	16.46
Nov	3.72	63.89	0.058	0.074	0.970	18.25
Dec	3.73	71.61	0.052	0.061	0.810	17.24

Hour of Day Statistics
Hour	Jan	Feb	March	April	May	June	July	Aug	Sep	Oct	Nov	Dec	Total	Records	Mean	Standard Deviation	Maximum
1:00	0.15	0.15	0.16	0.17	0.16	0.12	0.09	0.13	0.12	0.17	0.17	0.17	1.75	28.92	0.060	0.082	0.96
2:00	0.14	0.14	0.18	0.15	0.15	0.12	0.13	0.13	0.13	0.17	0.17	0.16	1.76	29.50	0.060	0.083	2.03
3:00	0.15	0.14	0.18	0.17	0.14	0.14	0.13	0.13	0.16	0.18	0.17	0.16	1.84	30.68	0.060	0.083	1.35
4:00	0.14	0.13	0.17	0.18	0.14	0.13	0.13	0.11	0.17	0.17	0.17	0.16	1.81	30.80	0.059	0.082	1.58
5:00	0.15	0.13	0.17	0.17	0.14	0.13	0.14	0.12	0.16	0.14	0.18	0.16	1.79	30.34	0.059	0.081	1.17
6:00	0.15	0.13	0.17	0.15	0.14	0.12	0.15	0.13	0.14	0.14	0.19	0.15	1.77	30.53	0.058	0.080	1.11
7:00	0.15	0.14	0.17	0.14	0.14	0.13	0.14	0.14	0.16	0.13	0.17	0.17	1.78	30.60	0.058	0.084	1.61
8:00	0.15	0.14	0.16	0.13	0.13	0.14	0.12	0.16	0.14	0.12	0.14	0.16	1.68	29.31	0.057	0.085	1.56
9:00	0.14	0.14	0.15	0.13	0.11	0.14	0.12	0.16	0.13	0.12	0.16	0.14	1.64	28.24	0.058	0.082	1.41
10:00	0.14	0.15	0.16	0.12	0.13	0.12	0.09	0.13	0.14	0.13	0.16	0.14	1.61	28.24	0.057	0.077	1.10
11:00	0.16	0.15	0.15	0.13	0.13	0.10	0.09	0.12	0.12	0.11	0.15	0.15	1.57	26.98	0.058	0.076	1.10
12:00	0.16	0.14	0.14	0.13	0.12	0.11	0.12	0.14	0.12	0.14	0.18	0.15	1.64	27.54	0.060	0.082	1.22
13:00	0.15	0.14	0.14	0.14	0.11	0.12	0.10	0.14	0.16	0.13	0.16	0.15	1.64	27.31	0.060	0.090	1.54
14:00	0.14	0.13	0.14	0.16	0.10	0.18	0.13	0.16	0.16	0.14	0.13	0.15	1.72	27.05	0.064	0.097	1.63
15:00	0.13	0.14	0.13	0.15	0.11	0.15	0.17	0.21	0.15	0.13	0.12	0.14	1.74	27.14	0.064	0.103	1.55
16:00	0.14	0.14	0.15	0.16	0.12	0.20	0.17	0.18	0.13	0.13	0.13	0.14	1.79	28.45	0.063	0.098	1.60
17:00	0.13	0.13	0.15	0.16	0.14	0.20	0.25	0.17	0.11	0.14	0.13	0.15	1.85	29.42	0.063	0.099	1.34
18:00	0.13	0.12	0.14	0.16	0.13	0.18	0.18	0.14	0.12	0.12	0.15	0.17	1.74	29.18	0.060	0.084	1.05
19:00	0.14	0.12	0.16	0.16	0.14	0.12	0.16	0.14	0.12	0.13	0.16	0.17	1.72	29.65	0.058	0.082	1.45
20:00	0.14	0.12	0.16	0.15	0.14	0.13	0.14	0.13	0.12	0.13	0.15	0.16	1.67	28.62	0.058	0.082	1.09
21:00	0.13	0.12	0.15	0.16	0.14	0.14	0.12	0.11	0.12	0.12	0.14	0.15	1.60	28.12	0.057	0.076	0.80
22:00	0.14	0.14	0.15	0.14	0.12	0.15	0.09	0.09	0.14	0.15	0.15	0.16	1.61	28.91	0.056	0.079	1.53
23:00	0.14	0.14	0.15	0.16	0.15	0.13	0.09	0.11	0.13	0.15	0.15	0.15	1.64	28.70	0.057	0.080	1.38
24:00	0.15	0.13	0.15	0.18	0.14	0.12	0.08	0.12	0.12	0.16	0.17	0.17	1.69	29.09	0.058	0.078	1.24

Day of Week Statistics
Weekday	Total	Records	Mean	Standard Deviation	Maximum	Duration
Sun	5.91	97.91	0.060	0.086	1.60	16.12
Mon	5.73	98.96	0.058	0.079	1.61	15.71
Tue	5.86	101.50	0.058	0.083	1.63	16.34
Wed	5.79	98.94	0.059	0.082	1.33	17.17
Thu	5.88	96.06	0.061	0.088	2.03	16.09
Fri	5.97	100.63	0.059	0.085	1.55	16.36
Sat	5.91	99.33	0.059	0.088	1.54	16.54

Year	Total	Records	Mean	Standard Deviation	Maximum	Duration (h)	Interevent (h)	≥0.00	≥0.10	≥0.25	≥0.50	≥0.75	≥1.00	≥2.00
1894	36.28	661	0.055	0.080	1.07	16.37	193	87	55	37	26	17	12	1
1895	40.11	602	0.067	0.097	0.93	12.93	189	91	63	40	24	18	13	3
1896	37.34	781	0.048	0.056	0.57	17.27	172	91	58	45	29	16	9	2
1897	40.08	635	0.063	0.083	0.67	11.41	173	100	65	46	29	15	12	2
1898	49.66	842	0.059	0.073	0.91	14.58	138	94	74	57	30	20	15	4
1899	34.61	606	0.057	0.090	1.22	15.71	213	83	48	38	26	17	11	1
1900	43.97	618	0.071	0.080	0.60	15.95	194	87	55	40	24	16	15	5
1901	48.60	669	0.073	0.095	1.24	15.40	217	90	60	39	29	23	15	5
1902	33.76	604	0.056	0.067	0.73	14.27	199	90	56	40	26	19	11	1
1903	41.24	728	0.057	0.074	0.65	19.07	160	89	64	41	28	19	11	3
1904	39.62	689	0.058	0.079	0.85	13.09	190	103	64	41	22	13	6	2
1905	32.17	612	0.053	0.084	1.00	17.88	217	79	52	33	24	16	7	1
1906	40.69	637	0.064	0.098	1.53	13.95	212	100	62	39	28	18	12	2
1907	37.56	655	0.057	0.078	0.68	15.00	189	94	58	43	23	16	12	2
1908	30.04	508	0.059	0.092	1.55	12.27	218	80	57	35	22	10	7	0
1909	39.37	654	0.060	0.071	0.51	16.21	193	82	55	41	22	16	10	3
1910	28.32	558	0.051	0.060	0.65	15.59	188	93	52	38	19	10	8	0
1911	35.77	655	0.055	0.079	0.95	15.92	184	86	58	37	26	17	10	1
1912	34.55	611	0.057	0.082	1.34	13.95	179	86	55	41	26	16	11	1
1913	38.01	679	0.056	0.076	0.91	17.56	184	82	61	41	28	20	8	2
1914	34.27	651	0.053	0.062	0.51	16.77	177	76	50	38	24	20	12	2
1915	38.76	590	0.066	0.109	1.17	16.11	238	79	49	35	22	14	9	4
1916	37.36	785	0.048	0.071	1.27	17.95	199	100	63	38	29	15	9	3
1917	38.99	658	0.059	0.094	1.24	15.32	210	93	55	38	23	16	13	1
1918	33.56	621	0.054	0.077	0.87	15.00	250	96	57	31	21	15	12	2
1919	42.41	753	0.056	0.076	0.66	17.38	183	89	60	42	30	22	12	2
1920	46.13	786	0.059	0.071	0.56	18.26	198	88	58	42	30	22	15	5
1921	42.04	659	0.064	0.118	1.45	17.49	197	91	52	41	23	14	10	4
1922	41.12	624	0.066	0.089	0.92	17.85	202	72	53	38	21	15	11	4
1923	34.72	626	0.055	0.067	0.54	11.83	184	84	62	45	20	13	9	2
1924	36.99	536	0.069	0.101	0.82	13.30	193	79	57	39	22	16	8	2
1925	40.17	643	0.062	0.083	0.70	13.06	159	85	62	52	26	17	10	1
1926	39.28	572	0.069	0.106	0.94	11.61	190	85	55	44	24	16	10	3
1927	40.90	649	0.063	0.094	0.99	13.08	164	100	66	48	33	22	9	0
1928	38.35	636	0.060	0.089	0.89	13.59	175	88	57	43	29	15	11	2
1929	37.15	677	0.055	0.073	0.79	13.57	184	86	58	46	26	15	11	1
1930	34.87	617	0.057	0.081	0.87	16.89	191	79	50	36	22	16	10	2
1931	43.45	695	0.063	0.081	0.61	19.95	199	81	52	37	28	22	14	3
1932	41.61	632	0.066	0.091	0.75	16.39	220	88	51	35	25	14	11	4
1933	46.20	778	0.059	0.091	0.90	18.17	206	95	55	38	28	20	11	3
1934	34.71	628	0.055	0.079	0.91	13.55	205	95	63	40	28	13	6	2
1935	32.94	602	0.055	0.072	0.68	17.32	238	82	44	34	20	15	11	2
1936	47.05	723	0.065	0.084	0.91	14.47	175	100	57	45	29	23	20	3
1937	43.37	682	0.064	0.087	0.81	16.33	169	90	61	48	26	18	12	5
1938	50.52	852	0.059	0.095	1.38	19.07	173	102	63	46	24	19	15	4
1939	32.42	637	0.051	0.060	0.38	15.10	206	88	54	40	25	9	8	2
1940	36.08	745	0.048	0.062	0.64	20.34	244	99	49	31	19	16	13	1
1941	30.88	566	0.055	0.075	0.97	15.46	226	78	49	37	22	13	11	1
1942	42.47	729	0.058	0.085	0.85	13.80	171	86	55	45	27	19	16	1
1943	32.23	621	0.052	0.075	0.74	17.51	192	99	52	38	22	13	6	3
1944	37.06	650	0.057	0.096	0.85	19.11	196	76	46	37	26	15	11	3
1945	47.28	881	0.054	0.076	0.97	18.33	154	107	70	49	31	24	12	3
1946	38.08	618	0.062	0.085	1.09	15.32	184	84	55	38	22	16	12	3
1947	37.90	576	0.066	0.103	1.31	18.22	220	72	48	37	24	21	13	2
1948	40.38	771	0.052	0.073	0.96	18.22	159	91	66	48	32	21	9	2
1949	31.56	604	0.052	0.088	1.58	12.67	187	89	60	41	24	10	4	2
1950	32.71	700	0.047	0.070	0.67	18.25	236	94	58	36	16	12	10	1
1951	46.97	811	0.058	0.076	0.74	15.31	152	102	67	51	32	24	17	2
1952	40.60	749	0.054	0.092	1.63	17.62	164	95	56	42	26	17	13	3
1953	57.73	837	0.069	0.088	0.66	18.09	164	90	58	47	34	27	21	8
1954	62.32	875	0.071	0.116	1.22	19.10	167	109	65	47	31	26	18	6
1955	56.50	726	0.078	0.153	1.60	17.00	177	97	57	42	30	22	17	5
1956	47.39	882	0.054	0.077	0.95	18.55	173	102	62	49	36	21	11	4
1957	33.92	639	0.053	0.068	0.57	17.59	190	83	53	36	22	13	7	3
1958	61.63	961	0.064	0.087	0.97	18.24	134	104	64	54	39	29	22	8
1959	51.41	857	0.060	0.093	1.07	18.77	168	100	67	48	35	25	16	3
1960	44.46	666	0.067	0.102	1.54	16.93	192	86	54	42	31	21	17	5
1961	47.84	751	0.064	0.085	0.95	16.51	172	89	60	45	31	22	17	4
1962	43.23	734	0.059	0.076	0.75	17.92	216	93	55	37	24	16	10	5
1963	34.84	657	0.053	0.067	0.72	14.86	190	86	60	40	26	13	7	2
1964	36.47	677	0.054	0.075	0.82	18.45	211	91	50	36	24	15	12	0
1965	23.71	590	0.040	0.047	0.42	17.38	251	90	45	30	17	7	6	1
1966	36.01	648	0.056	0.075	0.90	16.08	228	94	52	37	26	19	11	0
1967	47.51	810	0.059	0.089	1.56	16.58	161	94	67	48	26	20	17	4
1968	42.26	681	0.062	0.070	0.48	15.95	209	85	53	39	30	20	15	2
1969	47.89	720	0.067	0.078	0.50	19.17	199	84	55	40	27	19	15	5
1970	41.91	733	0.057	0.074	0.95	16.45	190	89	60	42	28	15	13	4
1971	35.67	704	0.051	0.066	0.54	15.47	188	87	60	40	25	16	9	1
1972	53.09	921	0.058	0.078	0.85	16.04	146	113	73	53	39	24	15	4
1973	42.76	748	0.057	0.082	0.97	15.21	152	96	61	51	31	16	11	2
1974	40.34	652	0.062	0.091	0.88	13.38	168	97	62	45	26	17	9	3
1975	45.80	858	0.053	0.063	0.57	19.36	180	90	58	43	27	19	13	5
1976	36.72	647	0.057	0.089	0.93	13.91	173	92	60	45	23	12	9	2
1977	44.17	822	0.054	0.063	0.44	17.42	175	94	65	43	28	22	16	2
1978	37.64	668	0.056	0.075	1.00	17.83	201	81	49	38	23	16	11	4
1979	44.17	779	0.057	0.084	1.08	19.28	180	92	58	41	26	22	15	5
1980	29.47	512	0.058	0.079	0.70	12.37	241	89	52	35	18	11	9	0
1981	35.71	679	0.053	0.065	0.80	20.57	223	86	55	35	21	15	8	2
1982	44.61	716	0.062	0.083	0.90	17.12	190	87	55	38	29	19	13	3
1983	53.60	779	0.069	0.079	0.60	16.60	165	96	61	47	34	24	18	5
1984	50.09	744	0.067	0.086	0.66	16.93	178	91	56	44	29	22	15	4
1985	36.58	696	0.053	0.106	2.03	16.49	174	98	58	44	25	14	8	2
1986	44.33	682	0.065	0.081	0.66	17.31	214	90	57	39	27	21	13	4
1987	45.48	749	0.061	0.079	0.75	19.30	202	82	51	39	29	21	13	5
1988	34.78	588	0.059	0.082	0.73	13.08	221	96	55	37	21	15	9	3
1989	42.42	781	0.054	0.073	0.70	17.04	132	96	66	45	29	21	13	1
1990	46.50	711	0.065	0.099	0.93	17.86	201	91	57	44	29	20	14	6
1991	42.25	680	0.062	0.085	0.72	18.31	197	82	54	38	26	18	14	5
1992	43.72	733	0.060	0.092	0.97	17.04	178	95	59	47	23	15	10	4
1993	43.21	754	0.057	0.076	0.63	14.79	184	100	59	43	33	21	14	2
1994	47.60	806	0.059	0.087	0.84	18.63	153	97	60	43	29	24	16	4
1995	35.12	662	0.053	0.078	0.66	16.93	174	95	52	40	24	18	11	3
1996	49.43	744	0.066	0.086	0.73	15.59	159	95	61	51	30	16	13	3
1997	30.25	619	0.049	0.060	0.58	16.09	206	95	49	35	21	9	6	2
1998	53.20	690	0.077	0.117	1.34	17.16	173	83	58	42	28	19	15	7
1999	37.83	584	0.065	0.105	1.31	14.88	188	85	52	41	25	15	9	2
2000	44.52	676	0.066	0.090	0.72	16.51	173	86	59	46	35	17	10	3
2001	29.64	522	0.057	0.089	0.98	14.09	186	81	49	32	20	10	6	2
2002	39.92	732	0.055	0.069	0.91	17.84	181	92	62	44	33	18	12	2
2003	40.78	706	0.058	0.088	0.96	15.65	203	101	64	40	29	21	13	0
2004	43.55	646	0.067	0.096	0.74	19.89	184	87	51	37	28	20	12	4
2005	41.19	714	0.058	0.070	0.57	17.41	183	92	63	44	27	16	10	2
2006	51.89	763	0.068	0.083	0.58	18.22	172	91	64	45	26	20	13	6
2007	38.96	653	0.060	0.102	1.61	15.90	210	90	56	37	26	17	11	3
2008	53.10	756	0.070	0.101	0.98	14.21	137	99	73	57	33	22	15	5
2009	42.32	734	0.058	0.074	0.74	15.74	159	92	68	49	33	20	12	2
2010	47.14	672	0.070	0.112	1.51	18.58	215	87	47	35	23	17	13	5
2011	50.13	765	0.066	0.084	0.81	18.04	159	98	66	51	36	27	20	2
2012	36.73	626	0.059	0.099	1.33	17.65	223	90	52	37	29	17	11	1
2013	37.09	643	0.058	0.080	0.75	16.56	168	96	53	40	19	13	11	2
2014	44.86	749	0.060	0.076	0.80	17.96	155	93	62	50	32	21	12	4
2015	34.76	657	0.053	0.073	0.50	17.00	216	91	52	38	25	18	12	2
2016	32.60	598	0.055	0.069	0.68	14.43	189	95	55	35	20	18	12	0
2017	41.20	765	0.054	0.079	0.69	20.05	195	96	61	39	28	19	13	2
2018	49.47	774	0.064	0.098	1.12	15.19	149	105	71	53	41	22	19	1
2019	46.92	782	0.060	0.100	1.41	13.16	160	109	76	49	30	22	15	1
2020	36.29	630	0.058	0.086	1.23	15.24	199	89	56	40	27	15	10	0
Mean	41.04	693.32	0.06	0.08	0.90	16.33	185.41	90.9	57.8	41.6	26.7	17.7	11.9	2.7

Longest drought = 36 days preceding 04/03/1915
Period of record = 127.00 years
Period missing = 0.00 years
Records = 88052
Mean event depth = 0.873 (≥.25 inches)
Annual event depth = 37.1 (≥.25 inches)
Mean event duration = 17.33 hours
Interevent coefficient of variation = 0.85 (excluding periods exceeding 40 dry days)
Interevent time = 12 hours
ARI: Average recurrence interval
AMS: Annual maximum series

Rank	Depth	Date	Event ID	Hours	Records	Maximum	ARI (y)
1	11.94	8/18/1955 6:00	2571	40.00	36	1.41	179.16
2	8.86	5/12/2006 20:00	4746	95.00	77	0.43	60.63
3	7.89	10/20/1996 4:00	4355	33.00	31	0.73	39.35
4	7.86	9/15/1933 24:00	1645	42.00	41	0.90	38.79
5	7.01	10/5/1962 8:00	2894	61.00	55	0.59	25.14
6	6.98	3/13/2010 11:00	4931	58.00	58	0.43	24.73
7	6.77	6/4/1982 17:00	3732	83.00	77	0.36	22.01
8	6.77	6/12/1998 16:00	4421	43.00	32	1.34	22.01
9	6.04	7/9/1921 2:00	1118	22.00	14	1.45	14.16
10	6.03	3/31/2004 11:00	4654	44.00	41	0.53	14.07
11	6.00	5/30/1984 17:00	3825	76.00	56	0.43	13.80
12	5.91	10/17/1932 16:00	1607	66.00	57	0.61	13.01
13	5.74	5/15/1954 20:00	2516	18.00	18	0.98	11.61
14	5.73	12/11/1992 4:00	4182	53.00	41	0.49	11.53
15	5.72	10/12/1895 15:00	69	39.00	39	0.64	11.45
16	5.64	9/10/1954 19:00	2531	23.00	18	1.22	10.84
17	5.47	7/21/1938 6:00	1852	80.00	46	0.78	9.61
18	5.40	7/1/1915 3:00	883	50.00	34	1.17	9.14
19	5.35	6/5/1986 13:00	3906	62.00	46	0.54	8.81
20	5.22	4/27/1904 3:00	448	72.00	50	0.37	8.00

Rank	Total	Date	Event ID	Gauge ARI (y)	Atlas ARI (y)
1	2.03	8/1/1985 2:00	3872	64	29
2	1.63	8/5/1952 14:00	2439	22	11
3	1.61	7/30/2007 7:00	4799	20	10
4	1.60	7/10/1955 16:00	2567	20	10
5	1.58	9/1/1949 4:00	2306	18	9
6	1.56	8/6/1967 8:00	3085	17	9
7	1.55	8/7/1908 15:00	616	17	9
8	1.54	6/4/1960 13:00	2800	16	8
9	1.53	10/9/1906 22:00	536	16	8
10	1.51	7/10/2010 15:00	4943	15	8
11	1.45	7/9/1921 19:00	1118	12	7
12	1.41	6/29/2019 16:00	5335	10	6
13	1.41	8/19/1955 9:00	2571	10	6
14	1.38	8/16/1938 23:00	1854	9	6
15	1.34	7/18/1912 17:00	766	8	5
16	1.34	6/13/1998 14:00	4421	8	5
17	1.33	7/18/2012 17:00	5029	8	5
18	1.31	9/2/1947 13:00	2218	7	5
19	1.31	9/10/1999 23:00	4473	7	5
20	1.27	7/3/1916 17:00	923	6	4

Rank	Total	Date	Event ID	Gauge ARI (y)	Atlas ARI (y)
1	2.85	8/1/1985 2:00	3872	90	37
2	2.51	8/19/1955 9:00	2571	46	20
3	2.35	7/9/1921 2:00	1118	33	15
4	2.28	7/1/1915 5:00	883	28	13
5	2.25	8/6/1967 7:00	3085	26	12
6	2.21	7/10/1955 15:00	2567	24	12
7	2.01	9/10/1999 22:00	4473	14	8
8	1.98	8/10/1917 6:00	966	13	7
9	1.92	8/24/1901 24:00	335	11	7
10	1.90	5/16/1954 4:00	2516	11	6
11	1.89	7/28/2007 16:00	4798	10	6
12	1.88	9/11/1954 12:00	2531	10	6
13	1.83	9/1/1949 3:00	2306	9	6
14	1.82	6/13/1998 14:00	4421	9	5
15	1.82	8/21/1894 13:00	25	9	5
16	1.80	8/5/1952 14:00	2439	8	5
17	1.78	8/25/2010 9:00	4947	8	5
18	1.78	7/30/1926 5:00	1344	8	5
19	1.73	10/9/1906 22:00	536	7	5
20	1.70	9/15/1904 7:00	466	6	4

Rank	Total	Date	Event ID	Gauge ARI (y)	Atlas ARI (y)
1	3.61	8/19/1955 9:00	2571	94	56
2	3.58	8/1/1985 1:00	3872	90	53
3	3.02	6/13/1998 14:00	4421	42	22
4	2.92	7/1/1915 5:00	883	36	19
5	2.63	8/10/1917 6:00	966	23	12
6	2.58	7/9/1921 19:00	1118	21	11
7	2.50	8/6/1967 7:00	3085	18	10
8	2.49	9/11/1954 11:00	2531	18	10
9	2.49	9/10/1999 21:00	4473	18	10
10	2.40	5/16/1954 4:00	2516	15	8
11	2.38	7/10/1955 15:00	2567	14	8
12	2.22	9/16/1933 7:00	1645	10	6
13	2.20	7/30/1926 5:00	1344	10	6
14	2.18	7/24/1926 8:00	1343	10	6
15	2.16	7/28/2007 15:00	4798	9	6
16	2.16	8/25/2010 8:00	4947	9	6
17	2.03	8/21/1894 13:00	25	7	5
18	2.03	8/26/1924 10:00	1249	7	5
19	2.03	9/1/1949 3:00	2306	7	5
20	2.01	9/15/1904 6:00	466	7	4

Rank	Total	Date	Event ID	Gauge ARI (y)	Atlas ARI (y)
1	5.46	8/19/1955 6:00	2571	131	135
2	4.18	9/11/1954 10:00	2531	51	32
3	4.15	7/31/1985 22:00	3872	50	31
4	4.03	5/16/1954 1:00	2516	45	26
5	3.71	6/13/1998 14:00	4421	33	18
6	3.62	9/10/1999 18:00	4473	30	16
7	3.53	9/16/1933 5:00	1645	27	15
8	3.37	7/1/1915 3:00	883	22	12
9	3.33	10/14/1990 1:00	4089	21	11
10	3.24	8/26/1924 9:00	1249	19	10
11	3.10	11/23/1992 3:00	4179	16	8
12	3.05	10/20/1996 6:00	4355	15	8
13	3.05	9/10/1924 2:00	1253	15	8
14	2.93	8/10/1917 5:00	966	12	7
15	2.79	9/15/1904 3:00	466	10	6
16	2.76	7/28/1911 10:00	722	10	6
17	2.70	12/6/1937 19:00	1818	9	5
18	2.66	7/9/1921 19:00	1118	8	5
19	2.61	7/17/2018 14:00	5278	7	5
20	2.60	8/6/1967 6:00	3085	7	4

Rank	Total	Date	Event ID	Gauge ARI (y)	Atlas ARI (y)
1	6.74	8/19/1955 5:00	2571	134	132
2	5.54	5/15/1954 21:00	2516	68	45
3	5.44	9/11/1954 5:00	2531	63	41
4	5.01	9/16/1933 2:00	1645	47	26
5	4.94	10/20/1996 5:00	4355	44	24
6	4.81	6/13/1998 7:00	4421	40	21
7	4.37	9/10/1999 13:00	4473	27	14
8	4.30	7/31/1985 16:00	3872	26	13
9	4.11	9/9/1924 22:00	1253	21	11
10	3.97	8/26/1924 3:00	1249	18	9
11	3.85	7/1/1915 3:00	883	16	8
12	3.63	10/13/1990 18:00	4089	12	6
13	3.59	6/6/2000 12:00	4506	12	6
14	3.48	9/14/1904 24:00	466	10	5
15	3.46	7/28/1911 6:00	722	10	5
16	3.43	11/22/1992 22:00	4179	9	5
17	3.38	7/9/1921 2:00	1118	9	5
18	3.24	10/13/1895 9:00	69	7	4
19	3.23	12/12/1992 2:00	4182	7	4
20	3.16	4/1/2004 13:00	4654	6	4

Rank	Total	Date	Event ID	Gauge ARI (y)	Atlas ARI (y)
1	8.35	8/18/1955 13:00	2571	148	134
2	6.65	10/20/1996 5:00	4355	61	39
3	6.04	7/9/1921 2:00	1118	41	24
4	5.82	6/13/1998 8:00	4421	35	20
5	5.74	5/15/1954 20:00	2516	33	19
6	5.64	9/10/1954 19:00	2531	31	17
7	5.63	9/16/1933 1:00	1645	31	17
8	5.14	12/11/1992 16:00	4182	21	12
9	4.96	10/12/1895 22:00	69	18	10
10	4.73	5/13/2006 10:00	4746	14	8
11	4.71	9/10/1999 8:00	4473	14	8
12	4.63	7/31/1985 14:00	3872	13	8
13	4.46	7/1/1915 3:00	883	11	7
14	4.37	8/25/1924 23:00	1249	10	6
15	4.29	4/1/2004 1:00	4654	9	6
16	4.27	9/9/1924 22:00	1253	9	6
17	4.26	10/5/1962 11:00	2894	9	6
18	4.25	9/3/1905 5:00	499	9	6
19	4.19	6/9/1931 8:00	1560	8	5
20	4.18	6/6/2000 9:00	4506	8	5

Rank	Total	Date	Event ID	Gauge ARI (y)	Atlas ARI (y)
1	11.94	8/18/1955 6:00	2571	200	278
2	7.89	10/20/1996 4:00	4355	48	36
3	7.86	9/15/1933 24:00	1645	47	35
4	7.79	5/12/2006 23:00	4746	46	34
5	6.77	6/12/1998 16:00	4421	27	18
6	6.74	10/5/1962 14:00	2894	27	17
7	6.33	3/13/2010 14:00	4931	21	13
8	6.04	7/9/1921 2:00	1118	18	11
9	6.03	3/31/2004 11:00	4654	18	11
10	5.98	6/4/1982 21:00	3732	17	10
11	5.74	5/15/1954 20:00	2516	14	9
12	5.72	12/11/1992 14:00	4182	14	9
13	5.72	10/12/1895 15:00	69	14	9
14	5.69	9/10/1954 2:00	2531	14	9
15	5.66	10/18/1932 8:00	1607	14	9
16	5.35	7/1/1915 3:00	883	11	7
17	5.10	3/17/1968 15:00	3111	9	6
18	5.00	6/5/1986 13:00	3906	8	5
19	4.96	6/9/1931 3:00	1560	8	5
20	4.94	4/27/1904 11:00	448	8	5

Rank	Total	Date	Event ID	Gauge ARI (y)	Atlas ARI (y)
1	12.47	8/17/1955 13:00	2570	201	238
2	8.34	5/12/2006 20:00	4746	49	32
3	7.99	10/20/1996 4:00	4355	42	25
4	7.88	9/14/1933 20:00	1645	40	24
5	7.68	6/13/1998 2:00	4421	36	21
6	7.01	10/5/1962 8:00	2894	26	15
7	6.98	3/13/2010 11:00	4931	25	14
8	6.53	6/4/1982 21:00	3732	19	11
9	6.04	7/9/1921 2:00	1118	14	8
10	6.03	3/31/2004 11:00	4654	14	8
11	5.99	5/30/1984 22:00	3825	14	8
12	5.91	10/17/1932 16:00	1607	13	7
13	5.82	9/9/1954 3:00	2531	12	7
14	5.74	5/15/1954 20:00	2516	12	7
15	5.73	12/11/1992 4:00	4182	12	7
16	5.72	10/12/1895 15:00	69	11	7
17	5.43	7/1/1915 3:00	883	9	5
18	5.35	6/5/1986 13:00	3906	9	5
19	5.27	7/21/1938 13:00	1852	8	5
20	5.22	4/27/1904 3:00	448	8	5

Rank	Total	Date	Event ID	Gauge ARI (y)	Atlas ARI (y)
1	12.47	8/17/1955 13:00	2570	185	198
2	8.86	5/12/2006 20:00	4746	58	34
3	8.07	10/20/1996 4:00	4355	41	21
4	8.06	6/12/1998 16:00	4421	41	21
5	7.96	9/14/1933 5:00	1645	39	20
6	7.01	10/5/1962 8:00	2894	24	12
7	6.98	3/13/2010 11:00	4931	24	11
8	6.77	6/4/1982 17:00	3732	21	10
9	6.26	5/29/1984 21:00	3824	15	7
10	6.06	3/31/2004 13:00	4654	14	7
11	6.04	7/9/1921 2:00	1118	13	7
12	5.91	10/17/1932 16:00	1607	12	6
13	5.90	9/7/1954 18:00	2530	12	6
14	5.86	7/20/1938 8:00	1851	12	6
15	5.79	10/12/1895 15:00	69	11	6
16	5.75	5/12/1954 18:00	2516	11	5
17	5.73	12/11/1992 4:00	4182	11	5
18	5.44	7/1/1915 3:00	883	9	5
19	5.39	4/27/1904 3:00	448	8	4
20	5.36	6/5/1986 13:00	3906	8	4

Rank	Total	Date	Event ID	Gauge ARI (y)	Atlas ARI (y)
1	13.52	8/17/1955 13:00	2570	168	201
2	10.37	5/9/2006 13:00	4745	63	49
3	8.96	6/2/1982 2:00	3731	36	22
4	8.45	6/12/1998 16:00	4421	28	17
5	8.37	9/10/1999 8:00	4473	27	16
6	8.07	10/20/1996 4:00	4355	23	13
7	7.96	9/14/1933 9:00	1645	22	13
8	7.95	5/15/1954 20:00	2516	22	13
9	7.75	3/31/1987 3:00	3942	20	11
10	7.67	7/18/1938 9:00	1851	19	11
11	7.64	5/26/1984 20:00	3823	19	10
12	7.52	6/7/2013 9:00	5066	17	10
13	7.15	6/9/1931 8:00	1560	14	8
14	7.07	9/10/1954 19:00	2531	13	8
15	7.06	10/5/1962 8:00	2894	13	8
16	7.06	3/11/2010 11:00	4931	13	8
17	6.74	3/12/1968 18:00	3110	11	6
18	6.40	12/11/1992 4:00	4182	9	5
19	6.30	7/9/1921 2:00	1118	8	5
20	6.29	3/31/2004 11:00	4654	8	5

Rank	Total	Date	Event ID	Gauge ARI (y)	Atlas ARI (y)
1	14.25	8/17/1955 13:00	2570	143	196
2	10.80	5/9/2006 13:00	4745	50	40
3	10.57	6/29/1921 22:00	1117	46	35
4	9.80	5/29/1982 5:00	3730	34	23
5	9.58	5/7/1954 2:00	2514	31	20
6	9.53	9/27/1962 10:00	2893	30	20
7	8.95	9/7/1999 3:00	4471	23	14
8	8.94	3/13/2010 12:00	4931	23	14
9	8.48	6/8/1998 18:00	4421	19	11
10	8.46	6/7/1931 12:00	1560	18	11
11	8.28	10/20/1996 4:00	4355	17	10
12	8.03	9/9/1933 2:00	1645	15	9
13	7.90	3/31/1987 3:00	3942	14	8
14	7.78	7/18/1938 9:00	1851	13	7
15	7.76	5/23/1984 19:00	3823	13	7
16	7.73	9/7/1954 11:00	2530	12	7
17	7.70	6/7/2013 0:00	5066	12	7
18	7.49	7/1/1915 3:00	883	11	6
19	7.06	11/3/1969 2:00	3171	8	5
20	6.97	3/10/1968 18:00	3110	8	5

Rank	Total	Date	Event ID	Gauge ARI (y)	Atlas ARI (y)
1	16.81	8/11/1955 17:00	2569	128	193
2	14.48	3/11/2010 11:00	4931	68	72
3	12.86	5/3/1954 9:00	2513	40	32
4	12.21	5/1/2006 22:00	4744	32	23
5	12.04	6/2/1982 2:00	3731	30	21
6	11.48	8/28/1933 17:00	1642	24	16
7	11.24	6/26/1921 9:00	1117	22	15
8	10.92	6/12/1998 16:00	4421	19	12
9	10.86	9/17/1962 19:00	2892	18	12
10	10.59	8/31/1954 0:00	2529	16	10
11	10.58	11/23/1992 2:00	4179	16	10
12	10.50	10/8/1996 17:00	4354	16	10
13	10.09	3/12/1953 22:00	2460	13	8
14	9.95	8/25/1924 23:00	1249	12	8
15	9.85	5/29/2013 22:00	5064	11	7
16	9.40	12/8/1969 4:00	3177	9	6
17	9.36	9/6/1999 12:00	4471	9	5
18	9.15	3/31/1987 3:00	3942	8	5
19	9.11	7/10/1938 2:00	1850	8	5
20	9.00	1/6/1979 4:00	3600	7	5

Rank	Total	Date	Event ID	Gauge ARI (y)	Atlas ARI (y)
1	17.19	5/9/2006 13:00	4745	87	92
2	17.16	8/7/1955 4:00	2568	86	91
3	15.36	3/11/2010 11:00	4931	50	41
4	15.25	4/16/1954 12:00	2510	48	39
5	13.65	5/23/1982 2:00	3729	27	19
6	13.39	6/26/1938 10:00	1848	25	16
7	12.93	6/29/1921 24:00	1117	20	13
8	12.86	8/20/1933 1:00	1640	20	13
9	12.19	3/15/1953 11:00	2461	15	9
10	12.05	11/21/1992 15:00	4179	14	9
11	11.94	5/31/1998 23:00	4419	13	8
12	11.91	10/11/1932 15:00	1607	13	8
13	11.57	5/19/2013 18:00	5062	11	7
14	11.55	9/22/1996 16:00	4351	11	7
15	11.43	8/12/1924 10:00	1248	10	6
16	11.35	3/31/1987 3:00	3942	10	6
17	11.10	9/14/1962 18:00	2892	9	6
18	11.04	7/30/1946 20:00	2177	9	5
19	10.90	8/31/1954 0:00	2529	8	5
20	10.89	3/31/2004 11:00	4654	8	5

Rank	Total	Date	Event ID	Gauge ARI (y)	Atlas ARI (y)
1	19.64	5/12/2006 20:00	4746	84	86
2	18.83	8/11/1955 17:00	2569	66	61
3	18.22	2/24/2010 1:00	4929	54	46
4	18.16	4/16/1954 12:00	2510	53	45
5	16.04	3/12/1953 22:00	2460	25	18
6	15.42	5/4/1998 1:00	4415	20	14
7	15.39	9/7/1996 19:00	4349	19	14
8	15.04	5/20/1982 15:00	3729	17	12
9	14.96	6/11/1938 10:00	1846	16	12
10	14.88	6/6/1959 14:00	2750	16	11
11	14.37	9/27/1962 3:00	2893	13	9
12	14.34	6/26/1921 9:00	1117	12	9
13	14.21	10/23/1953 9:00	2487	12	8
14	14.08	8/4/1933 3:00	1638	11	8
15	13.72	9/6/1999 12:00	4471	9	7
16	13.53	2/6/1983 20:00	3761	9	6
17	13.53	11/3/1992 4:00	4176	9	6
18	13.42	8/3/1954 9:00	2527	8	6
19	13.24	10/13/1895 1:00	69	8	5
20	13.14	7/31/1924 16:00	1245	7	5

Rank	Total	Date	Event ID	Gauge ARI (y)	Atlas ARI (y)
1	23.34	8/18/1955 6:00	2571	111	170
2	22.59	5/1/2006 22:00	4744	89	120
3	19.67	4/16/1954 12:00	2510	36	37
4	19.11	2/16/2010 9:00	4928	29	29
5	18.84	3/4/1953 1:00	2459	27	26
6	18.18	5/2/1998 0:00	4414	21	20
7	17.92	11/3/1969 1:00	3171	19	18
8	17.92	5/29/1982 13:00	3730	19	18
9	17.00	10/23/1953 9:00	2487	13	12
10	16.98	5/26/1938 15:00	1844	13	12
11	16.97	5/23/1959 21:00	2749	13	12
12	16.93	11/30/1957 13:00	2669	13	12
13	16.65	8/23/1996 20:00	4346	12	11
14	16.58	3/1/1983 18:00	3764	11	10
15	15.91	2/20/1933 7:00	1619	9	8
16	15.91	9/25/1962 23:00	2893	9	8
17	15.86	9/16/1932 5:00	1605	8	8
18	15.81	6/26/1921 9:00	1117	8	7
19	15.64	3/21/1901 11:00	313	8	7
20	15.33	7/20/1933 22:00	1637	7	6

Frequency Estimates
Duration	Average Recurrence Interval													GEV			Constraint adjustment
Duration	1-mo	3-mo	6-mo	1-y	2-y	5-y	10-y	25-y	50-y	100-y	200-y	500-y	1000-y	ξ	α	κ	Constraint adjustment
Event	1.00	1.73	2.28	2.74	3.62	4.63	5.53	7.00	8.41	10.2	12.3	16.0	19.5	3.363	0.6629	-0.3116	1.
1-hour	.270	.450	.580	.794	1.00	1.22	1.40	1.68	1.93	2.23	2.57	3.13	3.63	0.9442	0.1534	-0.2378	1.08
2-hour	.410	.650	.830	1.04	1.34	1.63	1.87	2.23	2.55	2.91	3.33	3.97	4.55	1.253	0.2170	-0.2044	1.04
3-hour	.500	.800	1.01	1.20	1.54	1.90	2.20	2.69	3.13	3.66	4.30	5.33	6.30	1.440	0.2491	-0.2622	1.02
6-hour	.680	1.11	1.36	1.68	2.00	2.41	2.79	3.46	4.15	5.04	6.20	8.29	10.4	1.901	0.2488	-0.3838	1.01
12-hour	.860	1.41	1.76	2.17	2.54	3.02	3.47	4.27	5.10	6.18	7.60	10.2	12.9	2.427	0.2870	-0.3959	1.00
1-day	.970	1.63	2.07	2.49	3.07	3.75	4.36	5.36	6.33	7.54	9.04	11.6	14.1	2.902	0.4405	-0.3211	1.00
2-day	1.04	1.78	2.30	2.80	3.54	4.42	5.23	6.62	7.98	9.72	11.9	15.8	19.7	3.317	0.5581	-0.3513	1.00
3-day	1.11	1.91	2.50	2.99	3.77	4.69	5.54	6.97	8.39	10.2	12.5	16.4	20.4	3.536	0.5871	-0.3464	1.00
4-day	1.16	2.06	2.68	3.24	3.94	4.81	5.64	7.07	8.51	10.4	12.8	17.1	21.5	3.729	0.5392	-0.3755	1.00
7-day	1.27	2.41	3.12	3.84	4.69	5.70	6.63	8.20	9.75	11.7	14.2	18.6	22.9	4.436	0.6414	-0.3475	1.00
10-day	1.31	2.79	3.58	4.30	5.24	6.36	7.38	9.10	10.8	12.9	15.7	20.4	25.1	4.957	0.7135	-0.3425	1.00
20-day	1.31	3.66	4.82	5.68	6.93	8.35	9.59	11.6	13.5	15.9	18.7	23.5	28.2	6.570	0.9414	-0.2982	1.00
30-day	1.31	4.24	5.86	7.01	8.46	10.0	11.3	13.4	15.4	17.7	20.5	25.0	29.2	8.045	1.070	-0.2655	1.00
45-day	1.31	4.56	7.16	8.88	10.6	12.4	13.8	16.0	18.0	20.2	22.8	27.0	30.7	10.14	1.275	-0.2182	1.00
60-day	1.31	4.56	8.36	10.5	12.7	14.7	16.3	18.7	20.7	23.0	25.6	29.5	33.0	12.08	1.519	-0.1811	1.00

90% confidence intervals
Duration	1-y	2-y	5-y	10-y	25-y	50-y	100-y	200-y	500-y	1000-y
1-hour	0.77-0.81	0.97-1.04	1.17-1.28	1.31-1.51	1.51-1.89	1.67-2.28	1.84-2.76	2.01-3.40	2.27-4.51	2.48-5.57
2-hour	1.00-1.06	1.29-1.38	1.56-1.71	1.75-2.01	2.01-2.48	2.22-2.94	2.43-3.53	2.64-4.25	2.95-5.52	3.18-6.81
3-hour	1.16-1.23	1.49-1.59	1.81-2.00	2.05-2.37	2.39-3.04	2.67-3.73	2.98-4.64	3.29-5.82	3.74-7.94	4.10-10.18
6-hour	1.63-1.70	1.95-2.06	2.30-2.53	2.59-3.02	3.03-4.00	3.40-5.11	3.80-6.66	4.29-8.85	5.07-13.24	5.78-18.20
12-hour	2.11-2.20	2.48-2.61	2.89-3.17	3.22-3.75	3.73-4.90	4.17-6.28	4.67-8.27	5.24-11.20	6.15-17.16	6.87-24.27
1-day	2.41-2.53	2.98-3.18	3.58-3.96	4.05-4.74	4.73-6.17	5.27-7.71	5.90-9.90	6.59-12.84	7.60-18.45	8.41-24.10
2-day	2.71-2.86	3.42-3.65	4.18-4.67	4.80-5.68	5.72-7.71	6.49-9.89	7.37-13.08	8.38-17.54	9.97-26.21	11.30-35.83
3-day	2.89-3.05	3.66-3.91	4.46-4.98	5.10-6.07	6.04-8.17	6.86-10.43	7.77-13.64	8.79-18.19	10.30-26.89	11.54-36.29
4-day	3.14-3.30	3.83-4.08	4.58-5.09	5.19-6.12	6.13-8.25	6.96-10.67	7.86-14.23	8.93-19.15	10.51-29.34	11.96-41.44
7-day	3.73-3.91	4.57-4.84	5.45-6.03	6.16-7.19	7.20-9.40	8.09-11.98	9.11-15.38	10.24-20.13	12.01-29.67	13.52-40.02
10-day	4.17-4.37	5.10-5.40	6.07-6.70	6.85-8.01	7.97-10.54	8.93-13.26	10.01-17.08	11.22-22.63	12.99-32.88	14.55-44.40
20-day	5.51-5.79	6.74-7.15	7.98-8.76	8.94-10.29	10.33-13.16	11.48-16.21	12.74-20.48	14.17-26.19	16.22-36.63	18.03-48.40
30-day	6.81-7.13	8.25-8.70	9.64-10.50	10.70-12.13	12.14-15.04	13.35-18.16	14.64-22.04	16.04-26.96	18.06-35.63	19.67-44.98
45-day	8.64-9.02	10.38-10.92	11.98-12.92	13.11-14.71	14.61-17.66	15.82-20.56	17.06-24.31	18.30-28.91	20.08-36.92	21.46-44.73
60-day	10.25-10.70	12.35-12.97	14.21-15.23	15.56-17.15	17.26-20.26	18.62-23.25	19.97-27.01	21.38-31.62	23.32-39.34	24.86-47.06

GEV distribution fitted using L-moments for ≥1 year
Empirical results for periods <1 year
NOAA Atlas 14 frequency estimates
Input file: C:\Calcs\MetData\MA\Boston\Logan.1h
Analysis completed: 06/19/2021 13:17
Elapsed time : 292.2 seconds
Developed by Mitch Heineman, Ajay Prasad, Constantine Karos, and Masoud Soltani. CDM Smith, 1991-2021