(As always, click on images to enlarge) After intense arctic cold across most of the Central and Eastern United States in the previous week, the week of January 29 to February 4 will start with brief moderation of temperatures, particularly from the Eastern Great Lakes through the Northeast - that won't last. Arctic air will be reinforced from midweek on, surging southeast from Canada again and sending temperatures 20-30 degrees below normal for some of the Eastern half of the nation, and below normal for a large portion of the country.
Precipitation is a bit less clear-cut in this regime, however. Last week, I was able to look and see a clear trigger for snow in the Northeast that prompted an above normal precipitation pattern in the previous forecast period. This forecast period, however, storm development and track is less clear, largely because the expansive high pressure over the Eastern United States that is delivering the cold air will block storm development through most of the forecast period. As the high degrades later in the period, a storm is likely to develop - hence, the area of above normal precipitation in part of the Southeast - but track beyond that is unclear at this point.