The low temperature forecast for last night had to be revised due to the amount of snow that fell yesterday. When you couple the clear skies & calm winds with the deep snow all over southern Louisiana, it produced an 'ice box' effect where the snow contributed to the air temperature readings. This is why the low temperatures in south Louisiana was actually colder than areas above McComb, MS where they got far less snow pack. No doubt the remaining snow tonight will once again cause the temperatures to plummet quickly once the sun goes down.