Boston’s Mild Winter Receives Cold Interruption Later Next Week

Fig. 1: ECM 10-day snowfall forecast across the East U.S. The Southern U.S. storm could be more freezing rain/ice for later next week.

Discussion: ECM indicates two snowstorms in their latest 10-day forecast. Winter Storm Warning’s are posted for the Northern Rockies to northwest Iowa this morning as a swath of moderate snow shifts eastward heading into the early weekend (Fig. 1). The snowfall event widens over the weekend with eastward progression to include the Great Lakes and New England. The following cold air mass is made more effective by the snow cover. Mid-to-late next week, ECM indicates a second snowfall event extending from northwestern Texas to Kentucky and across Virginia. Forecast confidence is low on snowfall amount which is substantial. The possible greater concern is that the bulk of the indicated snowfall area is freezing rain and ice. The snow cover increase across the northern states including New England supports the greatest bit from limited arctic air ahead in the U.S. is New England later next week. A consensus of all models indicates Boston dips into the single numbers at night late next week with several days of highs only in the 20’s (Fig. 2). This week has featured less cold medium-range forecasts and ECM ENS carries that theme this morning. One catalyst to less cold/warmer medium/extended-range forecasts is progression of the Madden Julian oscillation (MJO) into the equatorial Pacific (Fig. 3). The latest U.S. gas population weight HDD forecast indicates above normal national heating demand for next week into early February shifting to below normal national demand for mid-February (Fig. 4).

Fig. 2: All models indicate MJO shift into the equatorial West Pacific later next week into the following week which is a warming influence on U.S. climate.

Fig. 3: This week’s forecasts have trended less cold in the medium-range. However, Boston, MA is likely to receive rare (for this winter season) cold for Feb. 2-6.

Fig. 4: The gas population weight HDD forecast using all models, their consensus and compared to 24 hours ago plus the 10-day/30-day normal.