MJO shifts to the tropical North Atlantic next week. Supports tropical cyclone development.

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06/02/2021, 8:09 pm EDT
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Fig. 1: Madden Julian oscillation 14-day forecast according to ECM.

Discussion: During neutral ENSO, the Madden Julian oscillation (MJO) is normally active. During northern hemisphere summer, influence of the convection phase of the MJO causes an increase in wet monsoon moisture and tropical cyclone risk in neighboring longitudes. The ECMWF 14-day MJO forecast indicates anomalous convection in the tropical West Pacific (now) shifts eastward and across the tropical North Atlantic in 8-14 days (Fig. 1). Intensity of the MJO transition is marginal. However, the shift across the tropical North Atlantic in the 8-14-day period does support increasing organized convection in the Caribbean Sea to the Gulf of Mexico and west coast of Northwest Africa (Fig. 2). There is potential for a tropical cyclone to develop in this wet zone into early in the middle third of June.

Fig. 2: The MJO shift across the tropical North Atlantic in the 8-14-day period causes increased risk of a western North Atlantic basin tropical cyclone.