Global Relationship between Fronts and Warm Conveyor Belts and the Impact on Extreme Precipitation

AbstractExtratropical cyclones are responsible for many extreme precipitation events in the midlatitudes. Warm conveyor belts (WCBs) and fronts are known to be related to the uplift and hence the precipitation within cyclones. The authors have investigated the link between WCBs and fronts and how such a link impacts the occurrence of extreme precipitation events. WCB trajectories have been calculated from the ERA-Interim dataset, and low-level (below 790 hPa) and midlevel (790–600 hPa) WCBs have been considered. These have been matched with objectively identified fronts (i.e., characterized by an overlap of WCB and front somewhere along the front). About 10% of cold fronts, 8% of warm fronts (identified using a thermal criterion), and 15% of wind fronts (identified using a wind shift method) are matched with WCBs, while up to 70% of WCBs are matched with fronts. Some WCBs, especially in the Southern Hemisphere, are not matched with either type of front (up to 70% east of Australia). The relationship betwe...