A pattern change is indicated for the second half of January. Previously, a semi-permanent upper trough was located southeast of Brazil and enhancing historic rainfall for that nation the past couple months. The GFS 15-day outlook indicates a pattern change. An upper-level ridge crests just-off the far southeast coast of Brazil. The result is wetter weather for Argentina and drier/warmer climate for Brazil.

In today's midday update the 12Z GFS produces several major winter events driven by a strong -NAO pattern. First, an arctic gale on the New England Coast Friday night. Second, a late weekend East Coast snowstorm. Third, low latitude ice storm risk centered on Texas later next week.

December 2021 was the warmest on record for the U.S. The year of 2021 was 4th warmest on record. Both December 2021 and the year of 2021 averaged near normal for precipitation.

According to multi-variate ENSO index (MEI), analogs since 2000 having lengthy 2-year-plus La Nina signatures have been slow change phase and sometimes remain in weak La Nina. In 2022, based on the MEI analog there is a 2-in-3 chance ENSO is neutral or weak La Nina the second half of 2022 while El Nino risk is 1-in-3 chance.