An Investigation of Convective SIGMETs during the El Niño-Southern Oscillation and the Madden-Julian Oscillation

The El Niño-Southern Oscillation (ENSO) and the Madden-Julian Oscillation (MJO) are drivers of seasonal and intraseasonal climate variability, but there has been limited research on their extratropical impacts within U.S. domestic airspace. Prior research found that Convective SIGMETs (CSIGs) followed typical convective patterns over the United States (Slemmer, 2005). Understanding convection patterns during ENSO and MJO phases can help aviation forecasters provide impact-based decision support services to the aviation community. To explore these topics, a searchable CSIGs dataset (May 2012 - May 2024) was analyzed based on ENSO and MJO phases. Time periods for each ENSO phase (El Niño Advisory, La Niña Advisory, and periods with no active watches/advisories) were based on the Climate Prediction Center’s ENSO Diagnostic Discussions and time periods for MJO phases were obtained from the Australian Bureau of Meteorology.

Extensive analysis revealed distinct diurnal and monthly climatological patterns of CSIGs during different ENSO phases as well as distinct monthly patterns during different MJO phases. Additional research is being conducted to validate these initial findings and to further investigate the spatiotemporal distribution of CSIGs during MJO phases, including how such information might benefit the larger aviation weather enterprise.