Extreme Dutch Weather: Early winter convection; a line of interesting cells.

Friday, 3 January 2014

Early winter convection; a line of interesting cells.

The warmest 'third of Januar' since the Dutch temperature measurements started (AD 1901) was followed by the passing by of a line of TSTMS. Some of them were suspect of having rotational updrafts.
I departed from work somewhat earlier tot have the chance to drive through them.......
See link below:
3-1-2014 thunderstorm

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.