Relationship between atmospheric blocking and warm‐season thunderstorms over western and central Europe ...

• Main Authors: Mohr, Susanna, Wandel, Jan, Lenggenhager, Sina, Martius, Olivia
• Format: Text
• Language: English
• Published: Royal Meteorological Society 2019
• Subjects: 550 Earth sciences & geology; 910 Geography & travel; North Atlantic
• Online Access: https://dx.doi.org/10.7892/boris.138764; https://boris.unibe.ch/138764/

A statistically significant link is presented between atmospheric blocking located over the eastern North Atlantic and northern Europe and warm‐season thunderstorm activity over western and central Europe. Lightning data from 2001 to 2014 were used to identify thunderstorm days and blocking events were extracted from the ERA‐Interim reanalysis using an objective identification algorithm. The statistical link between the two phenomena is established through odds ratio analysis. Two areas – one over the eastern part of the North Atlantic and one over the Baltic Sea – were identified as locations where blocking influences the occurrence of deep moist convection in parts of western and central Europe. Based on the mean ambient conditions on days with blocking in these two areas, well‐known dynamic and thermodynamic mechanisms supporting or suppressing the development of thunderstorms were confirmed. The anticyclonic circulation of a block over the eastern part of the North Atlantic leads to a northerly to ...