Monday, 1 March 2010

Mesocyclone, wall cloud and funnel-like appearence (19-07-2008)

Several thunderstorms form the North Sea region came north of our house. From 'Leiden' and surroundings there came reports of a huge shelfcloud. http://www.weerwoord.be/includes/forum_read.php?id=832412&tid=832412 By surprise the southward region of some storms went over our house; I saw some rotation and in the southwest corner I saw the appearence showed below.

Later there came reports of a possible funnel near Utrecht spawn from another storm.

Estofex Level 1 region was closeby:

"... Parts of Belgium and Germany ...




Generally speaking the environment is prime for scattered thunderstorms over Germany as an intense mid - level streak pushes eastwards and cold mid- levels overspread the area from the west but we know that the devil is in the details and determines the final degree of storm organisation so we have to split the whole area in three subareas:........

 
... Parts of Belgium and west - central Germany ...




This area will see the strongest forcing, best shear but only limited instability release. We will go with a marginal level - 1 for this area as intense forcing and another SE - ward moving cold front could help to sustain a forced line of storms. Shear at all levels would be adequate for a few organized storms with a isolated large hail / tornado and strong wind gust threat. "