Madden Julian Oscillation To Regain Strength/Influence on Climate

Preliminary 2021 North Atlantic Tropical Cyclone Season Outlook And 2020 Review
01/27/2021, 7:04 pm EST
Solar Cycle 25 Is Underway
03/08/2021, 1:03 pm EST
Show all

As a reminder, the reason the MJO is tracked is due to its presence with intensity almost always leads to weather extremes including major storms at the longitude of the MJO location frequently with upstream/downstream (in the middle latitudes) effects. The arctic outbreak in February was triggered by emergence of an active MJO pattern near the Dateline.

Another pulse of MJO ahead. Possible implications are cooler in the extended-range East and lack of a major storm Corn Belt in 10+ days.

Fig. 1-3: Madden Julian oscillation 14-day and 30-day forecasts by ECMWF and global SSTA analysis.

Discussion: The Madden Julian oscillation (MJO) reactivates over the next 1-2 weeks shifting through phase_8 to phase_1 (far eastern Pacific to the Atlantic tropics). The 14-day ECMWF MJO forecast indicates impressive strength of the MJO is attained once entering phase_8 (Atlantic tropics) in 10+ days (Fig. 1). The extended-range forecast by ECMWF indicates MJO weakens in 2-3 weeks and returns to home base (in the early 2021 pattern) of Indonesia (phase_6) in 3-4 weeks (Fig. 2). Note that the MJO has a tendency to become intense when located over warm sea surface temperature anomalies (SSTA) as identified in the eastern tropical Atlantic and Indonesia (Fig. 3).

As a reminder, the reason the MJO is tracked is due to its presence with intensity almost always leads to weather extremes including major storms at the longitude of the MJO location frequently with upstream/downstream (in the middle latitudes) effects. The arctic outbreak in February was triggered by emergence of an active MJO pattern near the Dateline.

MJO phase_8 to phase_1 typically causes a warm Central U.S. pattern (phase_8) fading to cooler than normal in the East (phase_1). Operational forecasts are definitely aware of the warmth ahead in the Central U.S. But the MJO-inspired cooler change for the East in the 11-15 day period is not indicated. There are members of the mega-cluster ensemble which are cooler in the East in 10+ days. Traders should be aware of a weaker than indicated warm East 11-15 day forecast or possibly a cool reversal.

The precipitation pattern across the U.S. during MJO phase_8 is mostly dry and with a few exceptions that pattern is in the 10-day forecast. MJO phase_1 is typically stormy in the Southeast U.S. particularly Florida. Interestingly, MJO phase_1 is very dry in the U.S. Corn Belt and operational forecasts are indicating a major storm in that region. Traders should be aware of a potential much less stormy Midwest U.S. 11-15 day period.

The MJO affects all parts of the globe. There’s a lot of attention on South America right now (agriculturally). The influence of MJO P8/P1 in South America is much wetter for Brazil.