Northern Hemisphere Pattern Change Catalyst for Late January is an Evolving -PNA and +SCAND Pattern
01/17/2021, 9:47 am ESTChecking Medium-range Temperature Forecast skill Scores of All Models
01/26/2021, 11:43 am ESTDiscussion: Over-the-weekend the MJO forecast continues to strengthen (Fig. 1). The GFS is strongest and indicates a robust MJO phase_7 next week. In the short-term MJO phase_6 is organizing (and strengthening). The implications are increased risk of significant precipitation in the East-central U.S. Initially, plenty of snow is involved but later in the two-week forecast rain is favored. The MJO phase_6/phase_7 forecast also favors a warmer than normal climate east of the Continental Divide. Plenty of mild and wet Pacific/Gulf of Mexico influence in the likely pattern ahead. The Western U.S. is the cold bias region helped by increasing snow cover.
Globally, there is influence on Australia and South America given the emerging MJO phase_6/phase_7 regime. Slowly, a wet bias in Australia fades – likely by the middle third of February. The MJO shift favors increased anomalous wet climate across South America.
Above normal risk of tropical cyclone activity north and especially northeast of Australia in this pattern
The MJO phase_6/phase_7 regime should make La Nina weaker as trade winds ease and convection increases.