Coldest Night of the Season So Far…November 24th, 2012 at 8:26 pm by Tiffany Savona WAVY under Weather
Are you ready for the coldest night of the season? Yes we have seen temperatures drop below freezing over the past month across inland locations. But tonight, all locations, even coastal areas should drop to 32 degrees or below for a couple of hours. We will likely see a lot of 20 degree readings for inland areas. Our normal low temperature this time of year is 42 degrees. Keep in mind that the National Weather Service will not be issuing any more freeze warnings this year because the growing season has already ended.
Tonight, we will have an excellent set-up for what meteorologists call radiational cooling (maximum cooling overnight).
1. The sky will remain clear.
Most of the clouds are offshore right now. There are a few high clouds moving into the coastal areas, but these clouds are very thin and very high up in the atmosphere. Plus, these thin clouds should be clearing out over the next few hours. The Earth absorbs radiation (heat) from the sun during the day. Once the sun sets, this radiation will escape back into space. Clouds will block some of the radiation from escaping back into space, which is why temperatures do not drop as low when we have clouds in the sky. When we have a clear sky, all of this heat is lost and we have maximum cooling.
2. Light winds
Winds were much stronger this morning thanks to the cold front that moved in last night. Now, wind speeds range from 5-9mph. Light winds will allow the coldest air to sink to the surface.
3. Dry air
The dewpoint temperature is a measure of how much water vapor or moisture is in the air. I captured this graphic around 8 p.m. Dewpoints have already dropped into the teens and 20s, indicating that we have a very dry air mass in place across the region. Remember dry air warms and cools very efficiently. Therefore, the air temperature is going to fall very rapidly tonight, but will still stay above the dewpoint temperature.
If you still have any plants outside, it would be a good idea to bring them indoors for the rest of the season. Also be sure to bring the pets inside. Stay warm tonight!
Meteorologist: Tiffany Savona