At most risk are low-lying areas near streams and rivers.
The combination of melting snow and heavy rain that's expected to fall on Wednesday has prompted the National Weather Service to issue a flood watch for parts of New Jersey and Pennsylvania.
The watch, issued by the weather service's regional office in Mount Holly, is effective for Camden, Gloucester, Hunterdon, Mercer, Middlesex, Salem and Somerset counties, as well as northwestern Burlington and western Monmouth.
In Pennsylvania, the watch covers Berks, Bucks, Chester, Delaware, Lehigh and Montgomery counties, as well as Philadelphia.
The watch is effective from Wednesday afternoon through Thursday afternoon.
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Melting snow and periods of heavy rain could produce widespread flooding in low-lying areas as well as places with poor drainage, the weather service said in its watch. In addition, "minor to moderate river flooding is possible Wednesday night and Thursday across the Raritan and Passaic (river) basins of New Jersey and the Schuylkill basin in Pennsylvania."
As much as 2 inches of rain could fall in the region on Wednesday, forecasters said in a flood briefing posted Monday afternoon. The moisture will be coming from a cold front that will be pushing through the Garden State Wednesday night and moving off the Atlantic coast by Thursday morning.
A flood watch is not as serious as a warning, but the weather service advises residents living in areas that are prone to flooding to "be prepared to take action should flooding develop."
Len Melisurgo may be reached at LMelisurgo@njadvancemedia.com. Follow him on Twitter @LensReality. Find NJ.com on Facebook.