Madden Julian Oscillation Activates

NOAA/NHC 2024 Hurricane Outlook
05/24/2024, 4:43 am EDT
27C SST Threshold for North Atlantic TC Development Ahead of Schedule
05/29/2024, 11:02 am EDT
NOAA/NHC 2024 Hurricane Outlook
05/24/2024, 4:43 am EDT
27C SST Threshold for North Atlantic TC Development Ahead of Schedule
05/29/2024, 11:02 am EDT
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Highlight: Madden Julian oscillation strengthens over Maritime Continent.

Fig. 1: The MJO 15-day forecast utilizing all models indicates moderate intensity in phase_4 (Maritime Continent) for the next 10 days.

Discussion: The Madden Julian oscillation (MJO) has been inactive. However, a surge of convection inspiring heavy rainfall across the Eastern Indian Ocean to the Western Pacific Ocean (tropics) developed over the weekend and includes a tropical cyclone in the Philippines. The MJO 15-day forecast utilizing all operational models yields a transit through phase_4 (Maritime Continent) during the next 10 days followed by weakening as MJO approaches the cooling waters near the Dateline due to neutral ENSO (Fig. 1). The influence on climate maintains a wet signature across the tropical/subtropical West Pacific through the next 10 days (Fig. 2) while the subsidence phase of MJO dries out South America and reverses a recent cool regime across Argentina much warmer during the medium range (Fig. 3).

Fig. 2-3: The GFS percent of normal rainfall for the next 10 days across the West Pacific and next 15 days across South America.