Colder pattern to set up for Mid-Atlantic/NE US
Over the next week or so, upper-level high pressure ridging will intensify in two parts of North America that will lead to an influx of very cold air into the Mid-Atlantic/NE US during the second half of January. In particular, high-latitude blocking will develop with intensifying high pressure over Greenland and northeastern Canada as well as across the western parts of Canada and the US. The flow of air around the western Canada and US high pressure ridges will not only allow for the transport of air from northern Canada into the US, but it may also produce a “cross-polar” flow that could bring Siberian air (in a modified form) across the North Pole and into North America later this month. There has been some extreme cold in recent days across portions of East Asia and Europe with a few examples listed below:
1) -3°F in Beijing, China (lowest temperature recorded in Beijing since February 1966)
2) +1°F in Wakayanagi, Japan (lowest temperature ever recorded in Wakayanagi)
3) -29°F was recorded in Spain earlier this morning (lowest temperature ever recorded in Spain, still an unofficial reading)
Energetic pattern to continue
In terms of storm threats, the active weather pattern experienced in recent weeks across much of the nation will likely continue right through January. Multiple waves of upper-level energy across North America – in both the northern and southern branches of the jet stream – will result in multiple storm threats as we progress through the month. Each one of these systems will have to be addressed individually with respect to their potential impact zones and the ultimate interaction between the northern and southern branch waves of energy will dictate final storm track and intensity.
This week will close out with a low pressure system headed to the Carolinas from the northern Gulf of Mexico and it will produce accumulating snow in the southern Appalachians from northeastern Georgia to southwestern Virginia including such towns as Boone and Asheville in North Carolina). The precipitation shield from this system is quite likely going to stay to the south and east of the Mid-Atlantic’s I-95 corridor as it stays on a northeasterly track and moves to the western Atlantic Ocean.