New NOAA Long-lead Climate Forecasts Including Seasonal Drought Outlook
06/18/2026, 9:48 am EDT
Climate Impact Company Daily Feature
Issued: Sunday, June 21, 2026
Highlight: Intense positive phase global atmospheric angular momentum regime launched late June, characteristic of evolving El Nino climate.
Discussion: During APR/MAY, the multivariate ENSO index (MEI) was +0.4 which is just beneath the El Nino threshold (+0.5). Of note, the previous month was -0.5 (borderline La Nina) and the change from -0.5 to +0.4 is considered dramatic. Recently, a powerful convection phase of the Madden Julian oscillation (MJO) shifted across the tropical East Pacific and American longitudes. During that time, southern oscillation index (SOI) plummeted to extreme El Nino-like negative values (-3.0 or lower on 6 separate days in June). Implications are an El Nino climate should begin to develop quickly and a robust El Nino MEI observation is likely for July. Emergence of the strong El Nino climate is seen in the evolution of strong positive phase global atmospheric angular momentum (+GLAAM) by late JUN/early JUL (Fig. 1). +GLAAM is characteristic of a strong El Nino climate as westerlies aloft in the middle latitudes increase due to the interaction between increasing El Nino convection in the deep tropics and the dynamic forcing on mid-latitude upper airflow. The global wind oscillation (GWO) forecast (Fig. 2) indicates most of the forcing is in the eastern hemisphere (phase_5, phase_6, and phase_7). Sensible weather implications of P6 are an increase in tropical Pacific TC’s (Fig. 3), wet Midwest U.S. and severe weather risk uptick in the East U.S. while P7 increases heavy rain/thunderstorm risk for South America and Africa and a cooler shift in the East U.S. P7 is commonly a generator of negative North Atlantic oscillation (-NAO).
Fig. 1: Utilizing all models, the 15-day global atmospheric angular momentum (GLAAM) forecast reveals a developing strong positive phase typical of a developing El Nino climate.
Fig. 2-3: The 15-day global wind oscillation (GWO) forecast and 8-phase GWO schematic.