A cold morning to say the least is underway. Fryeburg as I write this is down in the upper teens for a solid freeze and a hard ground. In spite of nearly 100% sunshine, it will take many hours for temperatures to get into the 40's today.
From about 11 AM to 4PM will be anywhere from 38-44F. Once the sun goes down well before 5PM, temperatures will once again fall rapidly and another cold night lies ahead.
This time of year radiational cooling can cause a wide range of temperatures from the coastal plain to inland valleys. Take another look at the temperatures from 5AM above and notice Berlin New Hampshire at a mid-winter 12 degrees above zero. While this isn't the 25 below they often see in January, it does illustrate how calm winds and clear skies combine to give us radiational cooling.
The term is applied to these conditions because the heat of the day is able to radiate into space very effectively thus allowing the coldest temperatures possible by sunrise. If there are even a few clouds overhead, the process is interrupted because the heat that is escaping hits the clouds and bounces back to earth, keeping it significantly warmer.
A night with a blanket of high clouds versus a night with crystal clear skies can lead to temperatures 20 or more degrees warmer from the clouds acting like a blanket. Tonight, a few clouds and a light wind from the south should prevent northern New Hampshire from a repeat of this morning's cold, but coastal Maine will be just a chilly as this morning.
High pressure, or air that is piled up at the ground is responsible for our clear skies at night and brilliant sunshine during the day the first part of the week. As the high moves off the coast, the winds will turn more southerly and temperatures will moderate. By Wednesday I expect highs to be more typical of early November reaching back into the mid-50s.
Thursday is even milder with a brief return of 60 degree or higher temperatures. A front to our west will squeeze warm up northward up the coastline and also bring a period of showers. Showers appear most likely the second half of the day and overnight.
On Friday, the front will sweep offshore and bring a return to clear and colder conditions for the start of the weekend. I am hoping for nice weather Saturday as it's the annual Colby-Bowdoin football game. I will cheering on my alma mater, say hello if you see me, I always love to chat with folks who read the blog or have gardening questions.
The clear skies much of this week will give you and opportunity to check out Venus in the southwestern sky. On Tuesday, the setting crescent moon will be close to Venus for a nice celestial show. The image below shows some of the astronomical features in the eastern sky. The image is from earthsky.org.
Unfortunately, we had many clouds on Sunday morning that prevented us from seeing the sunrise eclipse. There are some great photos on the internet of the event and I encourage you to check them out. Here is one I found that someone took on a plane. Very cool.