A blizzard warning has been issued for northern Maine for late Thursday night through Saturday evening. While the initial arctic front will likely create snow showers and squalls that amount to an inch at most, whiteout conditions are still possible during this time frame. This is called a "ground blizzard".
The National Weather Service's definition for an official blizzard is a storm causing winds of 35mph or greater with blowing or drifting snow reducing visibility to a quarter of a mile or less for three consecutive hours. Notice that this definition does not mention anything about snowfall amounts or intensity. Most of the time, you need an intense snowfall to create these conditions, but not always.
Sometimes, gusty winds (35mph or greater), often associated with a cold front, can pick recently fallen snow up off the ground and blow it around creating a visibility of a quarter of a mile or less. This means that even on a sunny day, a blizzard is possible. This is what's referred to as a ground blizzard since the blizzard conditions are being created by snow already on the ground instead of snow falling from clouds.
Ground blizzards typically occur in the midwest, where the land is flat and wide open. The region also gets hit with some very intense winds, especially during the winter. This type of weather event is rather rare for New England as the land here is varied in elevation and completely covered in trees almost everywhere. These two factors make it hard for enough snow to blow around to create ground blizzard conditions.
As rare of an event as this is for New England, it is possible tonight through Saturday up in northern Maine. The winter storm watch states:
"Whiteout conditions are possible and may make travel treacherous and potentially life-threatening. Plan on slippery road conditions. The hazardous conditions could impact the Friday morning and evening commutes. Strong winds could cause extensive damage to trees and power lines."
The National Weather Service of Caribou, Maine goes on to say:
"In addition to the wind chills, blowing and drifting snow will cause significant travel problems, especially across northeastern portions of the forecast area where land use is more agricultural...Travel over open areas exposed to northwest winds will be dangerous at best and impossible at worst due to ground blizzard conditions and significant drifting making some roads impassable. Those who must travel across open areas Friday through Saturday morning should be prepared if they become stranded with a full tank of gas and winter survival supplies. It is also critical people do not leave their vehicles in whiteout conditions and very cold wind chills."
In addition to the potential ground blizzard, this area is expected to see the worst of the wind chills. Wind chill values of around -60 are possible. This, combined with the potential for power outages from the winds, could set up a very dangerous situation. Those who live in northern Maine must be prepared for the extreme cold and power outages.
