FIGURE 3.

Averaged life cycle of heatwaves in the Held–Suarez configuration, for heatwaves occurring at (top row) 65°N, (middle) 45°N, and (bottom) 25°N. Heatwaves are detected at all grid points at a specific latitude based on the definition found in the methods section. We composite temperature anomalies at 1,000 hPa (color shading), geopotential height anomalies at 1,000 hPa (green contours), and total geopotential height at 500 hPa (black contours) with respect to grid points experiencing a heatwave at different time lags. Crosses in the middle of each panel indicate the coordinates where the heatwave onset is detected at lag 0 [Colour figure can be viewed at wileyonlinelibrary.com]