Arctic air has arrived in the Midwest to Northeast U.S. high energy demand zone. In this zone temperature departures from normal are in the -10F to -25F range, coldest in Wisconsin and near Omaha, NE plus the west/central Ohio Valley. The moderated chill (south of snow cover) extends into Texas this afternoon also in the -15F to -25F temperature anomaly spread.
Forecast models continue to indicate the super cold will continue. The core of coldest anomalies (-20F to -30F) is over New England tomorrow and lingers into Friday. In fact, the New England snow cover may force the incoming strengthening arctic air chill linger into early next week.
This is important! Utilities in the NY/New England area need to realize that temperature departures from normal of -15F to -30F in these 2 regions could last for nearly 1 week! This would be a rare occurrence in recent history and a lot different from the warm winters’ of the past 2 years and colder than the preceding polar vortex winter(s).
Let’s take a look at some key northeast cities utilizing all models for max/min forecasts. In Hartford, CT high temperatures struggle of 10F tomorrow and early next week followed by only a slight recovery mid-to-late next week (Fig. 1). Forecasts for late next week have been revised colder. Similarly, Trenton, NJ is almost as cold with peaks tomorrow and early next week followed by limited recovery (Fig. 2).
Contributing to the concern for NY/New England (and northern Mid-Atlantic) is the just-run operational ECMWF model still positioning the polar vortex over the Northeast in days (Fig. 3). Temperatures are well below normal for an extended period of time.
The latest snow cover observations (Fig. 4) have over-achieved compared to the 10-day ECMWF snowfall forecast (Fig. 5). The latest 10-day ECMWF forecast clearly indicates where extreme cold will occur through the first week of January (Fig. 6).
Gas home heating population weight heating degree days could reach 300 for the week ending January 4th according to the Canadian ensemble (model) while other operational models are each above 280 which was the coldest start to January of the past 10+ years in 2014.
Fig. 1-2: All models and their max/min forecasts the next 15 days for Hartford, CT and Trenton, NJ is indicated.
Fig. 3: In 10 days the operational ECM lingers the polar vortex over the Northeast U.S.
Fig. 4-5: Current snow cover (left) and the snowfall forecast from 10 days ago by the ECMWF operational model.
Fig. 6: ECMWF 10-day snowfall forecast indicates zones susceptible to extreme cold are anywhere from the Midwest to Northeast. Also note the coastal Southeast snows which occur next week.