Regarding snow cover, the U.S. snow cover is below normal as mid-January arrives. However, given the lengthy negative arctic oscillation (-AO) the remainder of January, inevitable is a southward expansion of snow cover. The GFS snow depth forecast indicates Arkansas to the Tennessee Valley is snow covered in 2 weeks.

At midday, the 12Z GFS indicates evolution of a significant REGIONAL STRATOSPHERIC WARMING EVENT across eastern North America occurring mid-to-late 11-15-day period. The warming is likely in response to a moderate to strong eastward shifting convection phase of the Madden Julian oscillation (MJO) across the equatorial Pacific.

Is the heavy snowstorm indicated by 12Z GFS on the East Coast early next week correct. Of course not! However, the model makes the point that the climate pattern is in a strong negative arctic oscillation. Arctic air is forecast to drift cross-polar from Siberia and infiltrate North America. In this pattern, a snowstorm in the East is possible

DEC-25 was the 5th warmest early winter in the 131-year historical record. Almost the entire West observed the warmest December on record while the Northeast was seasonably cold. The U.S. precipitation pattern during DEC-25 ranked 37th driest on record featuring the driest December on record in Oklahoma with near record dryness for surrounding states, a classic La Nina signature. Meanwhile a wet La Nina bias was exceptional across the Northwest States.