Melting snow, Tuesday\u2019s rain and dropping temperatures have created the perfect environment for black ice on local roads tonight. Layers of ice already are forming in spots, with the temperature at just about freezing as of midnight in Shelton. The ice is most prevalent in untreated surfaces such as parking lots and sidewalks. The temperature is expected to drop to 21 degrees during the overnight, with clear skies helping to make it colder. St. Pat\u2019s drivers should be careful The many people heading from St. Patrick\u2019s Day celebrations should drive carefully and be ready for icy conditions. Same goes tru for people heading out early on Wednesday morning, with the daytime high only expecte dto be 36 degrees. The goods news is the strong winds from earlier Tuesday appear to have weakened a bit, although steady winds are expected Wednesday as well. People should expect colder temperatures for this week, with daytime highs in the 30s and nighttime lows in the teens and 20s, according to the National Weather Service. A mix of snow and rain is possible on Friday.