A significant ridge of high pressure will settle over the eastern two-thirds of the United States to start the new week. High pressure indicates sinking air, which makes it difficult for clouds to form, thus limiting the development of precipitation. This translates to is very beautiful weather. Pressures will max out at 1035 millibars over New England, which means that the bubble of high pressure is very strong.

High Pressure Set Up

High pressure spins clockwise, so on the eastern side of the high pressure there will be a northerly component to the wind. Up north over Canada is where the cold air is locked in, so some of that cooler air will be drawn into the eastern third of the country on Monday. As the high pressure center gradually shifts to the east, the northerly flow will become cut-off. Therefore Tuesday will be milder, with temperatures of 5 degrees above average for the Eastern seaboard. By Wednesday, the high pressure will move offshore. Winds will shift to the south, leading to a warmer flow. Temperatures on Wednesday will be nice and mild, ranging from 5 to 15 degrees above normal for the large majority of the nation.

The warmest air associated with this high pressure will occur on Monday for the central Plains and Rockies. Temperatures for this large area will range from 25 to 35 degrees above average, and there is even the potential for a few locations to top off at positive 40 degree temperature anomalies. Below, the operational European model forecasts the very expanse heat:

12z ECMWF Model Temperature Anomaly

If you’re a fan of the warmer temperatures, enjoy this week’s weather, because changes are coming fast. I discuss the changes for mid-December here.


Jackson is COO and Head of Content and Strategy of WeatherOptics. He also designed his own website and created the local company, Jackson's Weather. He has been forecasting the weather for southwestern Connecticut since March of 2015. He will major in Meteorology and Broadcast Journalism at the University of Miami in Fall 2018.

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