Snowy and Cold East U.S. Early to Middle January!

Fig. 1-4: ECM “weeklies” upper air forecast for the week ending Jan. 6, Jan. 13, and Jan. 20 with annotated cold and snow risk areas plus the U.S. gas population weight HDD forecast for the week ending Jan. 9, Jan. 16, and Jan. 23.

Discussion: So far, winter 2024-25 in the U.S. is unexpectedly colder than normal across the Appalachian States to the Atlantic Seaboard. Climate Impact Company generates climate forecasts primarily using regional SSTA patterns as predictors. The colder East U.S. forecast is supported by the relative coolness of the western North Atlantic SSTA pattern vs. very warm SSTA of the eastern and southern North Atlantic basin. ECM “weeklies” have noted this pattern for some time and maintain their cold upper trough pattern projection for early to middle January. Beginning later in the first week of January an upper trough begins to lock-in on the U.S. East Coast, well supported by conventional climate signals such as negative phase AO, NAO, WPO, and EPO. Cold is pushed into the Southeast U.S. including Florida late period while a snowy pattern develops from the Upper Midwest to New England (Fig. 1). During the week of Jan. 6-13, the upper trough amplifies as the high latitude blocking pattern strengthens. The sensible weather widens the cold air risk across the eastern half of the U.S., strongest in the Central Appalachian region (Fig. 2). The cold is made more effective by a snowy Northeast Corridor projection including all major cities from Washington to Boston. The upper low weakens but remains just after mid-month sustaining more snow and cold (Fig. 3). Natural gas prices increased 10-12% due to the colder forecasts late this past week. The U.S. gas population weight HDD forecast indicates the highest heating demand in the U.S. for winter 2024-25 is likely the week ending Jan. 9 followed closely by the week ending Jan. 16 (Fig. 4).