Snow Melt & Ice/Debris Jams
Flooding due to snowmelt happens when rapidly warming temperatures quickly melt the snow. The melted water runs off the already saturated ground and into nearby streams and rivers, causing them to rapidly rise and, in some cases, overflow. According to Dave Robinson, the New Jersey state Climatologist at Rutgers University, 12 days after the blizzard of 1996, New Jersey had rain. Temperatures in the 50’s melted almost 2 feet of snow in only 12 to 18 hours, causing significant flooding throughout the state.
Another example was in 1996 when heavy rains, mild temperatures, and rapid snowmelt caused serious flooding in the Delaware River Basin. At Belvidere, New Jersey, the river rose over six feet in less than 30 minutes. Water levels exceeded flood stage by nearly seven feet at Riegelsville, New Jersey and over five feet at Yardley, Pennsylvania.