Witnessing A Classic Shelf Cloud over Luxembourg, Germany (credit: Meteo Europe)

DISCUSSION: Within the last 24 hours, there has been a fairly impressive increase in the coverage of deeper convection across parts of western and northwestern Europe.  During the last 24 hours, a weak (but slightly invigorated) piece of mid-level energy was propagating across western Europe.  As it did so, the surface low pressure helped to shift the larger-scale regional wind field direction from a northeasterly to more of a southeasterly orientation.  Hence, this wind direction change helped to increase the influx (i.e., the amount of incoming air from a given region) of warmer air from the greater Mediterranean Sea.  As this warm air coming north increased with time, this helped to bolster the overall amount of convective instability as a result of the warmer air closer to the surface being coupled with much cooler air aloft.  

This increasing unstable lower-to-upper atmospheric combination led to a regional atmospheric environment which was much more conducive for deep convective development.  As shown in the footage above, one such convective storm developed into a severe thunderstorm which exhibited a classic shelf cloud.  Shelf clouds often form in convective situations wherein there was effective low-level lift which helped to create the layered cloud deck which was observed as a shelf cloud out ahead of the aforementioned severe thunderstorm.

To learn more about other high-impact weather events occurring across Europe, be sure to click here!

©2017 Meteorologist Jordan Rabinowitz