TABLE 5: RAINFALL DEPTHS FOR VARIOUS RETURN PERIODS AND STORM DURATIONS FOR RANDOLPH COUNTY

DEPTH (Inches)
Duration	Return Period (Years)
	2	5	10	25	50	100
5 min.	0.43	0.50	0.56	0.64	0.71	0.78
10 min.	0.67	0.80	0.90	1.04	1.16	1.27
15 min.	0.84	1.02	1.14	1.33	1.48	1.62
20 min.	0.97	1.19	1.35	1.59	1.76	1.94
30 min.	1.11	1.38	1.58	1.86	2.07	2.29
40 min.	1.23	1.54	1.77	2.08	2.33	2.58
50 min.	1.32	1.66	1.92	2.26	2.54	2.81
60 min.	1.39	1.76	2.03	2.40	2.69	2.98
1.5 hrs.	1.65	2.04	2.28	2.62	2.96	3.18
2 hrs.	1.66	2.05	2.29	2.63	2.98	3.20
3 hrs.	1.77	2.29	2.53	2.92	3.17	3.54
4 hrs.	1.88	2.48	2.92	3.28	3.64	3.92
5 hrs.	1.95	2.60	3.00	3.35	3.70	4.05
6 hrs.	2.06	2.61	3.04	3.39	3.73	4.10
7 hrs.	2.10	2.80	3.15	3.78	4.13	4.55
8 hrs.	2.12	2.88	3.28	3.92	4.24	4.80
9 hrs.	2.16	2.97	3.33	3.96	4.32	4.86
10 hrs.	2.20	3.00	3.40	4.00	4.40	4.90
12 hrs.	2.50	3.05	3.48	4.03	4.44	4.95
14 hrs.	2.52	3.08	3.57	4.20	4.62	5.18
16 hrs.	2.56	3.20	3.68	4.24	4.70	5.20
18 hrs.	2.61	3.24	3.78	4.32	4.77	5.40
20 hrs.	2.68	3.40	3.80	4.40	4.80	5.46
24 hrs.	2.85	3.55	4.04	4.56	5.10	5.51

 

Data taken from Technical Paper #40, "Rainfall Frequency Atlas of the United States for Durations from 30 Minutes to 24 Hours and Return Periods from 1 to 100 Years." (1961) also from NWS Hydro35, "Five to 60-Minute Precipitation Frequency for Eastern and Central United States." (1977 )