In Zusammenarbeit mit meteoradar
https://sturmforum.ch/
Quelle:The PV fold seems to be an important feature associated with stronger tornadoes. However,
the physical connection is not clear. Possibly, the tropopause fold leads to high
vorticity values below it. This can cause strong differential vorticity advection in combination
with the jet streak, which leads to a strong upward motion acting as a trigger
of convection. Eventually, a strong destabilization caused by cooling of the upper troposphere
enhances severe convection. However, strong convection is not necessarily
associated with tropopause folds. So, further investigations of this PV feature and its
connection with tornadoes are needed.
:
Quelle: http://estofex.org/cgi-bin/polygon/show ... recast.xmlStorm Forecast
Valid: Thu 23 Jul 2009 06:00 to Fri 24 Jul 2009 06:00 UTC
Issued: Wed 22 Jul 2009 22:03
Forecaster: GATZEN
A level 2 was issued for eastern France, most of Germany, nothern Alps, western Poland, and Czech mainly for large hail, severe wind gusts, and tornadoes.
...
DISCUSSION
Eastern France, Germany, northern Alps, northern Austria, Poland, and Czech Republic
...
North of the Alps, instability, low-level vertical wind shear, and veering profiles may increase in the afternoon and evening hours in the range of low surface pressure moving eastward. As convection will likely spread into this region from the west, thunderstorms will likely intensify and become well-organized including long-lived supercells and bow-echoes. Large to giant (5-10 cm) hail, severe winds, and tornadoes are not ruled out when this scenario becomes true. As models indicate a lot of uncertainties, a level 3 is not issued at this time, but an upgrade may be required during the period. Convection will spread into northern Austria, Czech Republic, and southern Poland in the evening, while severe threat will likely continue. After midnight, thunderstorms will likely weaken further east.
