U.S. Floods of 1984

By C.A. Perry, B.N. Aldridge, and H.C. Ross of the USGS

Two major storms created flood conditions throughout March 1984 in Georgia. On March 5 through March 6, a storm produced flooding in southern Georgia as well as northern Florida. Floods with recurrence intervals of 50 years or more occurred on creeks in southern Georgia. A severe storm producing high winds, tornadoes, and intense rains hit Georgia on March 27 and 28. This storm produced 50-year floods in southern Georgia, as well as severe coastal flooding along the Atlantic seaboard. Tides in Chesapeake Bay were 1.6 ft above the normal high tide.

One of the worst floods in northern New Jersey occurred April 5 through April 7 as a result of 2 to 8 in. of rain combined with snowmelt and saturated soil conditions. The storm that hit the Atlantic seaboard at the end of March created ideal conditions for flooding in New Jersey. The March storm had left as much as 8 in. of snow across much of the State, and its immediate melting caused high discharges on rivers, high lake levels, and saturated soil before the April rains. Thirteen streamflow-gaging stations in the Passaic River Basin recorded new maximum discharges. Streamflow-gaging stations throughout northern New Jersey recorded discharges with recurrence intervals from 20 to 100 years.

During the first week of May, a series of thunderstorms produced widespread and flash flooding throughout the Tennessee Valley and surrounding area. Eastern Kentucky was the hardest hit by the floods, but parts of Tennessee, West Virginia, and Virginia also flooded.

The worst flooding in Tulsa, Oklahoma, history occurred May 26 and May 27. A series of large thunderstorm cells developed over Tulsa and did not move for more than 7 hours. Official rainfall reports from the storms were as much as 12 in. of rain in an 8-hour period. There were several unofficial reports of as much as 15 in. of rain.

The wet winter of 1984 in the Western and West-Central States caused a large accumulation of snow in the Colorado River Basin and the Great Basin of Utah and Nevada. The spring thaw conditions were very similar to 1983, and many of the same areas flooded as a result of snowmelt. Extensive flooding occurred in the upper Missouri River Basin of southwestern Montana, the Snake River Basin of Idaho, the upper North Platte River Basin in Colorado and Wyoming, and the Colorado River Basin and the Great Basin during April, May, and June.

A series of severe storms plagued the central and upper Midwest for 3 weeks starting in late May and ending in early June. Repeated and intense thunderstorms produced excessive amounts of rainfall over parts of the seven-State area of Kansas, Missouri, Iowa, Minnesota, South Dakota, Nebraska, and Wisconsin. Record and near-record streamflows occurred at several streamflow-gaging stations. Turkey Creek in Nebraska had a maximum discharge 1.3 times the estimated discharge of the 100-year recurrence interval. In southeastern South Dakota, the maximum discharge of the James River near Scotland also exceeded the 100-year recurrence interval.

Hurricane Diana made landfall September 14 on the North Carolina coast. Coastal flooding, winds, and, in some areas, riverine flooding were severe. Riverine flooding was not uniformly severe due to the dry conditions prior to the hurricane and the sandy nature of the coastal plain soils, which minimized the surface runoff. Discharges recorded in south-central North Carolina did, however, reach the estimated 100-year recurrence interval.

A series of thunderstorms produced record rains and severe flooding from October 18 through October 27 in parts of Texas, Louisiana, Arkansas, and Oklahoma. The most severe floods were in southern Texas and Louisiana. A strong active front became stationary in southern Texas and produced record rainfall in the Corpus Christi area. Unofficial reports state that as much as 25 in. of rain fell in 3.5 hours in areas north of Corpus Christi. Long-time residents described the flooding as the worst in the area's history.

Source: USGS.