Both GFS and ECM regenerate a cold upper trough in the Northeast U.S. to Quebec sector as the middle third of January approaches. The forecast explains why a surge in U.S. heating demand is projected by CFS V2 and ECM for the week of Jan. 3-9.

A colder pattern across West/Central Europe emerges in the medium range according to ECM. During the colder transition, a large area of precipitation centered on Central Europe is indicated. As the colder weather strengthens, precipitation is over to mostly snow for Central to Southeast Europe and the Southern Mountains.

The cold burst into the U.S. next week remains in the forecast easing in the 11-15-day period. Interestingly, ECM maintains a colder edge to the mid-to-late December forecast based on heating degree day projections while the CFS V2 is much warmer. The HDD forecasts are heavily weighted by the high population East U.S.

After a warm autumn, a significant pattern change starting meteorological winter. A much colder forecast for the East trending colder during the 6-10/8-12-day period since late last week. Increased snow cover across Southern Canada into the Northern U.S. inspires the effectiveness of the cold air delivery. Significant heating demand, days when the average temperature is >10F colder than normal, is projected Nov. 29-Dec. 5 across both PJM and SERC sectors.