Why does weather radar not report some precipitation?
The National Weather Service's 148 WSR-88D Doppler radars can detect most precipitation within approximately 90 mi of the radar, and intense rain or snow within approximately 155 mi. However, light rain, light snow, or drizzle from shallow cloud weather systems are not necessarily detected.—wunderground


As Ron Beyer commented, the METAR KEWR 010251Z 03012KT 5SM -DZ BR BKN007 OVC012 14/13 A3025 RMK AO2 SLP243 P0000 60002 T01390133 58001 shows light drizzle.