Top 20 Flood Events
(based on number of flooded MARFC forecast points)
| Rank |
Date of Crest |
MARFC Points |
Min |
Mod |
Maj |
Unk |
Weather Summary |
| Hydrologic Definitions |
| 1 |
1/19/1996 - 1/23/1996 |
140 |
34 |
47 |
58 |
1 |
Southerly winds, high dewpoints and intense rainfall caused a rapid snowmelt. |
| 2 |
6/21/1972 - 6/27/1972 |
119 |
19 |
19 |
80 |
1 |
Hurricane Agnes made landfall again over southeastern New York on June 22 and moved westward into Pennsylvania. Rainfall totals from June 20-25 range from 2-3 inches in the Upper Potomac to 18 inches near Shamokin, Pennsylvania. |
| 3 |
3/6/2011 - 3/18/2011 |
112 |
71 |
31 |
10 |
0 |
Two succesive rainstorms produced 1 to 4 inches followed by 1 to 5 inches. Some spots in NJ picked up 8 inches. |
| 4 |
9/6/2011 - 9/15/2011 |
108 |
34 |
42 |
32 |
0 |
The remnants of tropical storm Lee moved up the Appalachian Mountains and interacted with a quasi-stationary east-west front. 10 to 15 inches fell at numerous locations in central PA/NY. |
| 5 |
3/17/1936 - 3/20/1936 |
97 |
12 |
18 |
66 |
1 |
Two successive rainstorms combined with snowmelt flooded the Eastern Seaboard from Virginia to Maine. estimates were over $1 million. |
| 6 |
6/26/2006 - 7/1/2006 |
92 |
29 |
27 |
36 |
0 |
A stationary front and thunderstorms brought widespread, but locally heavy rainfall to the area. Total precipitation amounts ranged from 4-6 inches over the Lower Delaware to 9-11 inches over the headwaters of the James. |
| 7 |
4/1/2005 - 4/4/2005 |
88 |
33 |
32 |
23 |
0 |
A Maddox Synoptic Type system produced 1-2.5 inches of rainfall over the North Branch Susquehanna and Lower Potomac, and 2-4 inches of rain over NJ and PA. |
| 8 |
9/17/2004 - 9/20/2004 |
85 |
19 |
31 |
34 |
1 |
The remnants of Hurricane Ivan, combined with a cold front, produced an average rainfall amount of 2-4 inches in NY, 3-7 inches in PA, 1-3.5 inches in NJ and 2 inches in WV. |
| 9 |
8/17/1955 - 8/21/1955 |
72 |
17 |
19 |
35 |
1 |
Hurricane Diane made landfall 5 days after Hurricane Connie. Hurricane Diane produced several inches of rain with locally heavier amounts of 10 to 20 inches. |
| 10 |
9/25/1975 - 9/29/1975 |
70 |
23 |
24 |
22 |
1 |
The remnants of Hurricane Eloise combined with a cold front and produced very heavy rainfall in the Mid-Atlantic. Washington, D.C. reported 9.08" of rainfall. |
| 11 |
1/21/1979 - 1/27/1979 |
61 |
26 |
20 |
14 |
1 |
A significant low pressure system produced 2 to 4 inches of rain throughout New Jersey, Eastern Pennsylvania and Virginia. |
| 11 |
2/14/1984 - 2/16/1984 |
61 |
23 |
29 |
9 |
0 |
A strong closed low pressure system moved through the region and was quickly followed by a secondary low pressure system. Rainfall from both systems totaled 2 - 4 inches and widespread flooding was reported in 5 states. |
| 13 |
3/28/1993 - 4/4/1993 |
56 |
34 |
19 |
1 |
2 |
Rainfall and snowmelt caused flooding throughout the Mid-Atlantic from March into April 1993. |
| 14 |
1/25/2010 - 1/28/2010 |
55 |
40 |
14 |
1 |
0 |
A strong low pressure system produced 2- 5 inches of rain in 24 hours. |
| 15 |
1/25/1978 - 1/28/1978 |
53 |
28 |
20 |
5 |
0 |
The Cleveland Super Bomb produced heavy rainfall totals of 1 - 4 inches on top of a 6 inch snowpack and caused significant flooding throughout most of the region. |
| 16 |
12/4/1950 - 12/10/1950 |
52 |
36 |
14 |
1 |
1 |
Snowmelt combined with rivers running high from the recent flood event. |
| 16 |
3/15/1986 - 3/16/1986 |
52 |
35 |
17 |
0 |
0 |
A low pressure system produced more than 1 inch of rainfall, with. locally higher amounts of 3 inches. |
| 18 |
5/22/1942 - 5/24/1942 |
51 |
22 |
24 |
5 |
0 |
Periods of heavy rain fell on May 20-23; as much as 5 to 7 inches of rain fell over some of the flood area on May 22 |
| 18 |
11/25/1950 - 11/30/1950 |
51 |
20 |
20 |
11 |
0 |
Record breaking cold air spawned a coastal "bomb" that retrograded back to the lower Great Lakes underneath a deep closed vortex. Several inches of rain fell across the area. |
| 20 |
2/24/1979 - 2/27/1979 |
50 |
23 |
22 |
5 |
0 |
A few days before the flooding, a blizzard dumped 16-24" of snow across the region. Then, rain showers associated with a low pressure system produced 1-4 inches of rain and melted several inches of the snowpack. |
Appreciation is extended to The Pennsylvania State University Department of Meteorology for providing access to the PSU Reanalysis Maps and to David Roth of the Hydrometeorological Prediction Center (HPC) for providing access to HPC hurricane information.
RFC Reanalysis Maps are provided internally by the Middle Atlantic River Forecast Center and the State College, Pennsylvania Forecast Office.
Daily weather maps data were issued daily from January 1, 1871 to April 14, 1968 and then again from Semptember 1, 2002 to present. The daily weather maps were issued in a weekly format from April 15, 1968 to August 31, 2002. We have tried to provide 6 days of maps ahead of the first crest and one day after the last crest. Therefore addional maps will usually be seen from April 14, 1968 to August 31, 2002.
Data provided by the U.S. Geological Survey
Additional support for this project was provided by the Susquehanna River Basin Commission, National Weather Service and Penn State University (PSU) Department of Meteorology. Special thanks to Michael Kozar (PSU student) for writing numerous weather summaries in the Floods by Events section.
Questions should be directed to Charles Chillag or Alaina MacFarlane.
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