While we were celebrating our Independence Day on July 4th, Summit Station in Greenland may have experienced the coldest July temperature ever recorded in the Northern Hemisphere at -33°C (-27.4°F). Much of Greenland has been colder-than-normal for the year so far and has had record or near record levels of accumulated snow and ice since the fall of last year. The first week of this month was especially brutal in Greenland resulting in the record low July temperature and it also contributed to an uptick in snow and ice extent - despite the fact that it is now well into their summer season.
Summit Station (also known as Summit Camp) is a high-altitude (10,551 feet) year-round research station in central Greenland and its exact coordinates actually can change since the ice sheet underneath is often on the move. Typical daily maximum temperatures at Summit Station are around -35°C (-31°F) in winter (January) and -10°C (14°F) in summer (July). The record low temperature of -33°C (-27.4°F) on July 4th was more typical of the daily maximum temperature expected during the winter month of January. [Source of information on July low temperature record at Summit Station, Greenland].
The accumulated snow and ice on Greenland has actually run at record or near record levels throughout this year and this well above normal trend began during the fall season of 2016. In recent days, there was a sharp uptick in snow and ice associated with the brutal cold air mass (indicated by arrow on top portion of plot). It was just five years ago in 2012 (red line on bottom portion of plot) when Greenland experienced unprecedented melting of snow and ice as revealed by satellite imagery. Should this trend with near record or record accumulated snow and ice in Greenland continue into the upcoming winter season, it could play an important role in our weather here in the Mid-Atlantic region and potentially improve prospects for snow as Greenland can be an important source of cold air.
The current conditions at Summit Station, Greenland: overcast skies, northerly winds at 14 mph, and relatively normal temperatures at -10.5°C (13°F). More accumulating snow is expected over the next week or so; especially, across the southern part of Greenland.
Meteorologist Paul Dorian