Date of Award




Document Type


Degree Name

Doctor of Philosophy (PhD)


Department of Atmospheric and Environmental Sciences

Content Description

1 online resource (ii, viii, 152 pages) : illustrations (some color)

Dissertation/Thesis Chair

Ryan D. Torn

Committee Members

Paul Roundy, John Molinari, Chris Thorncroft


African easterly waves, ECMWF, Ensemble, Predictability, Atmospheric waves, Numerical weather forecasting, Cyclones, Cyclone forecasting, Ocean-atmosphere interaction, Convection (Meteorology)

Subject Categories

Atmospheric Sciences | Meteorology


African easterly waves (AEWs) are the primary synoptic-scale weather feature found in sub-Saharan Africa during boreal summer. Many studies have used observations and idealized models to highlight processes associated with the movement and growth of AEWs, yet there have been few studies documenting the performance of operational ensemble prediction systems (EPSs) for these phenomena. Here, the predictability of AEWs in ECMWF EPS forecasts is assessed during two periods of enhanced AEW activity (July--September 2007--2009 and 2011--2013). Specifically, AEW predictability is analyzed through three main areas of focus: 1) verifying AEW position and intensity forecasts, and assessing their relation to convective errors; 2) evaluating environmental features associated with AEW intensity uncertainty; and 3) understanding AEW intensification differences for individual forecasts.