Extreme Dutch Weather: Some wanna be supercells in spring 2014.....

Thursday 26 June 2014

Some wanna be supercells in spring 2014.....

Spring season unto now did not know very interesting convection that I managed to see or reach. Around Pentecost (June) several set ups looked favorable, but......

Some examples of convection I did see on april 25, may 9, 10, 22 and 23.

Some explanation.....

When a thunderstorm has a longer living rotating updraft (mesocyclone) we call it a 'supercell'. A supercell is a relatively rare appearence in Holland; only on a few days a year one or more can be spotted. They can only exist under specific wind conditions. The top of the storm is often not that heigh as that of their bigger brothers in eg. the US. They often bring extreme weather with large hail and even tornado's being possible. A so called 'wallcloud' is a lowering under the stormcloud out of which a tornado can form. The last photo from the 1st of October 2006 shows a wall cloud.

Another type of tornado is not associated with a mesocyclone. It can appear below a stormbase when there are less windy conditions. Although relatively seldom they appear more often than the 'real' tornado. I prefer to call them 'spouts'.

Other weatherphenomena I'm interested in are 'shelfclouds' and 'mammatus' clouds.