NOAA 2001-004
Contact: Bob Chartuk

Threat of Ice Jams and Rapid Snow Melt Loom Over Northeast River Basins

With mild winter seasons of the past few years a distant memory, Winter 2001 has set the stage for the greatest risk of flooding in the Northeast in three years, according to a special winter flood potential forecast issued today by NOAA's National Weather Service.

Recent snow storms and below normal temperatures have created an above-normal threat for flooding in northern New Jersey, extreme northeastern Pennsylvania, and southern New York State, including the Catskill area, the Weather Service reports.

"People in these areas should have a heightened awareness for the chance of flooding this season, especially ice jam flooding due to the freezing of many local rivers," said Sol Summer, hydrology division chief for the NWS Eastern Region.

Snow depths in the parts of Susquehanna, Delaware, Raritan, and Passaic River Basins are running 20-60 percent above normal at this time, Summer said. "And below-normal temperatures have created extensive river ice which extends well into Virginia--a condition not observed for the past several years," he said. "While not an immediate problem, these atypical river ice conditions will be closely monitored as winter continues."

In contrast, below normal flood potential exists in the Ohio Valley and in the Carolinas where river flows are below normal. Drought conditions also persist in the central and western Carolinas, the Weather Service said.

For the remainder of New York State and New England, the winter flood risk is expected to be normal, with snow depths of 5-10 inches and extensive river ice coverage prevailing throughout the region. Although areas of far western New York near Buffalo have received near record snowfall this season, snowmelt that occurred in mid-December has returned the flood potential to normal.

"While the river flood potential conditions are varied across the East, keep in mind that historically, the most devastating winter river floods have been associated with a combination of heavy rainfall, rapid snow melt, and/or ice jams," Summer noted. None of these conditions, however, are expected in the next two weeks.

National Weather Service River Forecast Centers and Weather Forecast Offices will continue to monitor and forecast the 2001 winter/spring flood potential and will provide public updates on alternating Fridays beginning Jan. 19 and extending into April.

Residents can monitor National Weather Service flood information in various ways including NOAA Weather Radio, local media, and on the Internet at