La Nina 2020-21 has entered the mature phase. All dynamic forecast models indicate La Nina will begin to weaken during quarter 1 of 2021 shifting to neutral phase during quarter 2 of 2021. Specific climate influences are likely due to this transition on the U.S., South America and Australia.

Thirty tropical storms in 2020 across the North Atlantic basin breaks the record of 28 set in 2005. The number of hurricanes (13) and intense hurricanes (6) was slightly below the 2005 record (15 and 7 respectively). Surprisingly, despite the number of events in 2020, the accumulated cyclone energy (ACE) index was 179.7 ranking 9th highest in the 1950-2020 climatology.

The northern hemisphere sea ice extent ranks 2nd lowest on record for the September 2020. The only year in which northern hemisphere sea ice was less abundant was 2012. The lack of sea ice does not mean that winter ahead will be warm.

Late season heat in Iowa last week coupled with deep layer soil moisture deficit over the northern state and widespread soil moisture deficts in the shallow soil moisture produced a borderline flash drought episode. Deep layer soil moisture deficits are spread across the North-central U.S., western Great Plains and Southeast U.S. Fortunately, early autumn cool weather and likely a wet regime in the Southeast eases additional flash drought risk.