Winter Storms Could Lead to Flooding
State Climatologist weighs in on potential flooding
This winter's harsh weather has put Bergen County, as well as the rest of New Jersey, in a "precarious position" for flooding when the snow melts, State Climatologist Dr. David A. Robinson said.
Snowpacks which have accumulated since December's blizzard need a "well-behaved melt" in order for New Jersey to avoid widespread street flooding problems, Robinson said. By well-behaved, Robinson meant that temperatures need to rise gradually over time for a for a snow melt; ideally, temperatures would be in the 40s during the daytime and freezing at night, which would stop the melt for 8-12 hours at a time.
What New Jersey doesn't want is for the melting to "all occur in short order due to warm weather" accompanied by rain, Robinson said. According to Robinson's figures on Monday morning, a 16-inch snowpack in Tenafly has 2.76 inches of water, a 17.1-inch pack in Hawthorne had 3.49 liquid inches, and a 17.5-inch pack in Oakland had 4.30 liquid inches.
The liquid is stuck—and waiting to be unleashed—because "it's anything but fresh snow on the ground now," Robinson said.
"That's almost a month's worth of precipitation sitting in the snowpack," he said.
Flooding issues are exacerbated in towns like Fair Lawn, which is bordered by the Passaic and Saddle rivers. Though it's not a historic problem in New Jersey, there is potential for "ice jam flooding" in rivers, meaning that ice gets loose and caught around the bend, Robinson said.
Additionally, this winter's snow has blocked many catch basins, meaning that when the melting starts, "some streets are going to turn into moats as rain comes down."
New Jersey's worst flooding situation in recent memory came during the blizzard of 1996, when temperatures rose to 50 degrees less than two weeks after storms in December and early January. There "was flooding all over the Northeast, including New Jersey," Robinson said.
Flooding isn't inevitable, Robinson said, but it's definitely something to keep an eye on statewide.
"Until we see grass starting to appear, it's going to be a major concern," he said.