The advisory is in effect from 8 p.m. Monday to 11 a.m. Tuesday.
The wintry mix is predicted to fall across the interior of southern Connecticut as well as most of the Lower Hudson River Valley, bringing an end to the record warm temperatures seen in recent days.
Up to an inch of snow could fall, along with up to a tenth of an inch of ice.
The storm will develop across the metropolitan area Monday night, moving from west to east.
"There will be a prolonged period of sleet and freezing rain across interior portions of the tri-state area into Tuesday morning," the weather service said.
The weather conditions could cause slippery roads and sidewalks, with larger problems on elevated surfaces and at higher elevations, the weather service said.
The storm will cause traffic difficulties, including slippery conditions and limited visibility.
Drivers are urged to use caution on the roads from Monday evening into the morning commute on Tuesday.
Before the storm arrives, Monday will be mostly sunny, with a high near 40 and wind chills of 25 to 30 degrees. Overnight lows will fall into the upper 20s.
Click here to follow Daily Voice Armonk and receive free news updates.