World: Greatest One-Minute Rainfall
| Record Value | 31.2mm (1.23") |
|---|---|
| Date of Record | 4 / 7 [July] /1956 |
| Formal WMO Review | No |
| Length of Record | 1948-present |
| Instrumentation | Recording Rain Gauge "in satisfactory exposure" |
| Geospatial Location | Unionville, MD [38°48'N, 76°08'W, elevation: 152.18m (499ft)] |
References
Engelbrecht, H.H. and G.N. Brancato, 1959: "World Record One-Minute Rainfall at Unionville, Maryland." Monthly Weather Review 87(8):303-306; Krause and Flood, 1997: Weather and Climate Extremes, US Army Corps of Engineers Topographic Engineering Center pp. 89;
Discussion
Krause and Flood (1997) note that the total precipitation during the storm was 91.0 mm (3.6 inches) of which 72 mm (2.84 in) fell during a 50-minute period from 2:50 to 3:40 P.M. Rainfall was masured with a recording raingauge located in satisfactory exposure. Some 13 points pertaining to functioning of the gauge were considered in evaluating this record by H.H. Engelbrecht, then State Climatologist for Maryland and T.E. Hostrander, who was Substation Insprector. It was concluded that "... 1.23 inches of precipitation occurred in an estimated period of one-minute or less." The recording rain gauge chart (shown below) indicates that at chart time 3:23+ the pen was at 2.47 inches on the chart scale and at chart time 3:32- it was 3.70 inches.
Additional Images
Closeup Satellite Image of Modern Unionville, MD, USA
Regional Satellite Image of Modern Unionville, MD, USA