12:20 PM | *Next Arctic blast arrives this weekend in the Mid-Atlantic…Thanksgiving week looks chilly*
The unfolding weather pattern across North America over the next couple of weeks virtually assures a colder-than-normal month of November for the Mid-Atlantic region and a quick start to the winter season. An initial Arctic blast this past weekend resulted in numerous record low temperatures and it is increasingly likely that a second Arctic blast arrives in the Mid-Atlantic region by Sunday of the upcoming weekend. Beyond that, “high-latitude blocking” in the upper part of the atmosphere is likely to help keep much of the chilly air in place around here during much of Thanksgiving week.
Temperatures for much of this week will be quite moderate compared to the unseasonable chill of the past weekend; however, even with that moderation, it’ll stay primarily below-normal for this time of year. Another serious shot of cold air looks likely to arrive in the Mid-Atlantic region by Sunday of the upcoming weekend and it appears that this overall colder-than-normal weather pattern will continue right through Thanksgiving week. The weekend Arctic blast is likely to result in an impressive “lake-effect” snow event for those areas in and around the still relatively warm Great Lakes. As cold Arctic air flows over the warmer waters of the Great Lakes, the lower atmosphere destabilizes and snow showers/snow squalls are likely to be the result in those typical “lake-effect” regions of the Northeast and Great Lakes.
Abnormally high pressure will settle into northern Canada by the weekend and this type of “high-latitude blocking” pattern will likely help to sustain the colder-than-normal conditions around here right through much of Thanksgiving week. Looking even farther ahead, there are reasons to believe that the prospects for additional “high-latitude blocking” events this winter season are quite good with some favorable signals discussed extensively in the “2017-2018 Winter Outlook” including the continuation of low solar activity and the current high snow cover levels in the Northern Hemisphere. As far as snow is concerned in the near term, there can be some isolated snow shower activity on Sunday in the immediate I-95 corridor, but chances are much greater in the higher elevations to our north and west.
Meteorologist Paul Dorian