As Maine recovers from as much as 21″ of snow Thursday, the stage is set for another 2-5″ for parts of the state Saturday. On its heels, a major storm composing of 1 to 2 feet or more of snow, high winds, and rough seas arrives Sunday afternoon and continues through Monday.
Saturday’s snow comes courtesy of a weak clipper from the west. This appears to be a prolonged event, starting over western areas in the wee hours of the day and spreading eastward during the morning. Snow starts of light in nature, and then picks up with intensity over coastal areas into the afternoon.
High temperatures for the day range in the single digits north to the teens south. Wind out of the north at 5-15 mph keep wind chill values around 0° of the north and mountains, and single digits for the coast.
Snow ends from west to east Saturday night, but the break appears short lived.
Flurries and snow showers are possible in areas Sunday morning as outflow ahead of the the nor’easter filters into the region. The heavier snow begins late Sunday afternoon over southwestern areas and overspreads the state Sunday night.
A Major Nor’Easter Sunday Night Into Monday
The key components to a strong storm is robust upper level energy, plenty of moisture, and rapid development. This storm has all three components.
A look at upper level energy shows a very strong, sharp upper level low pivoting over the region. This is also known as a negative tilt. When that happens, it triggers rapid development of surface pressure. As the above model idea indicates, there is plenty of upper level energy to work with for this storm.
The cut-off upper level low seen over of Baja California is a key player in this storm as the moisture that feeds it comes from it.
Essentially there is a moisture river that starts with the cut-off upper level low over the southwest and the southern jet stream delivers it. This storm has available moisture from the west coast, Gulf of Mexico all the way up the eastern seaboard.
Model estimates indicate a general 1-2″ of liquid to reach the surface with this event for most of the state. Some quick math indicates 1-2+ feet of snow is possible. This is ratio dependent… away from the shore will be lighter, fluffier snow, closer to the shoreline a heavier, wet snow.
The storm hits open Atlantic Ocean water in the vicinity of the New Jersey shore, south of Long Island. This is the spark that ignites the gas can.
There are still questions on forecast track with this storm. While models are more or less in agreement of a Gulf of Maine track, how close it comes to the shoreline remains in question.
Given the amount of cold air over the region, cold air damming as a result of north/northeast winds will likely keep the bulk of the precipitation as snow. A track closer to the state brings the chance for sleet to mix in at the coast as temperatures rise above freezing between 5,000 to 10,000 feet.
High wind is also a concern for storms such as this. Coastal areas especially need to be aware of potential power outages due to strong wind and heavy, wet snow on power lines.
Shoreline areas should be aware of battering waves in the range of 15-25 feet, beach erosion, and storm surge in the 1-3 foot range that may cause flooding in the hours before and after high tide, which appear around midnight and noon on Monday.
Anytime there is rapid intensification there is room for all kinds of surprises. Storms can over perform in areas as a result. There is also the risk of “dry slotting” when the cyclone intensifies so quickly that dry air works into the storm and can knock total precipitation down.
Special thanks to Tropical Tidbits and Pivotal Weather for their written permission to use their graphics in this post. Use of WeatherTAP images used within their written permitted terms of media use policy. Additional forecast information supplied by the National Weather Service, WeatherBELL Analytics and AccuWeather Professional.
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