In October 2020 the Rutgers University Snow Laboratory snow cover analysis reveals 10.26 million square kilometers across North America which is (by far) the highest amount for the month observed in the 1970-2020 climatology.

-PNA patterns represent a persistent cold upper trough over Southwest Canada and/or the Western U.S. Frequently, -PNA patterns are compensated for by an upper ridge across the East U.S. associated with positive North Atlantic oscillation (+NAO). The described pattern is fully developed in the 6-10 day period and likely to linger through the 11-15 day timeframe.

Tropical Storm Zeta formed in the western Caribbean Sea earlier today. Zeta is forecast to start moving northwestward tonight and reach the northern Yucatan Peninsula tomorrow night and gain hurricane intensity into the south-central Gulf of Mexico later Tuesday. The immediate environment improves and supports the forecast track and intensity. However, a shear axis and cooler northern Gulf waters plus an approaching upper trough from the west makes the central Gulf to landfall forecast very uncertain.

The most recent NCEP CFS V2 Nino34 SSTA forecast indicates a robust La Nina ahead including a January 2021 (cold) peak of -2.6C. If correct, the January Nino34 SSTA would be the coolest in the 1950-2020 climatology. Previously, the coolest Nino34 SSTA for January were in the -1.64 to -1.98 range with the 1989 La Nina the strongest on record (for January).