-AO/-NAO Pattern Keeps East Half of U.S. Cold Through February

Fig. 1: Latest NOAA/NWS weather watch, warning, and advisory areas.

Discussion: New York and New England plus South Carolina are the only states not affected by a weather hazard this morning. Two snowstorms cause Winter Storm Warnings from Kentucky to Virginia and Kansas to Illinois (Fig. 1). Winter Storm Watch is posted for Lower Michigan. Extreme cold (arctic air) shifts into Montana and the northern Great Plains. Freeze Warning is issued for the San Joaquin Valley ahead of an atmospheric heavy rain/snow event for late this week. Dense fog is clogging shipping channels on the Gulf Coast this morning. The NBM 48-hour snowfall forecasts identify the TUE/WED storms in Virginia and into the Midwest (Fig. 2). The northeast quadrant of the U.S. is in a snowy pattern peaking with widespread 6-15 in. of snow from the Ohio Valley to New England this weekend (Fig. 3). Severe thunderstorms roll across Louisiana/Mississippi/Alabama tomorrow with the same area hit again on Saturday (Fig. 4-5). In the West, the incoming heavy precipitation event is focused on THU/FRI when coastal flooding heavy mountain snow affects California (Fig. 6). The U.S. gas population weight HDD forecast is becoming impressively cold for next week and late February with a significant colder revision since yesterday (Fig. 7).

Fig. 2-3: NBM 48-hour snowfall forecasts for TUE/WED and the weekend.

Fig. 4-5: NOAA/SPC severe weather outlook for tomorrow and Saturday.

 Fig. 6-7: The GFS 48-hour precipitation total forecast for THU/FRI in the West U.S. and U.S. gas population weight HDD forecast using all models, their consensus, comparing with yesterday and the 30-year/10-year normal.