Storm Forecast
Valid: Mon 25 Jul 2016 06:00 to Tue 26 Jul 2016 06:00 UTC
Issued: Mon 25 Jul 2016 03:32
Forecaster: VAN DER VELDE
A level 1 was issued for S Germany mainly for isolated excessive convective rainfall.
A level 1 was issued for the Baltic States mainly for isolated excessive convective rainfall.
A level 1 was issued for western Balkan mainly for isolated severe convective wind gusts.
A level 1 was issued for the southern Balkan and S Italy mainly for large hail and severe wind gusts.
SYNOPSIS
A large area of Europe has a slightly to moderately unstable airmass under very weak flow conditions and with weak triggers, mainly orography. Dynamics are found around a low pressure system over Italy and the Balkan, as well as a more intense low over Great Britain and SW Norway. This low pushes a cold front slowly through France and W Germany, as well as Denmark and SW Norway.
DISCUSSION
Approximately 500-1500 J/kg MLCAPE is found in the GFS model over the Baltics to Central Europe and the Balkan. Over the Baltics and southern Germany the LCL heights will likely remain below 1000m while the mid level lapse rates are modest, suggesting moister profiles which, along with storm motion vectors of only a few m/s imply a threat of local excessive convective rainfall. The deep layer vertical shear is weak at about 5-10 m/s. Therefore the local triggering should result mainly in single cell convection with short life spans.
The above is also valid for the NW Balkan and Hungary, but with drier profiles and steep lapse rates the excessive precipitation chance is reduced while local severe wind gust potential is elevated. Delta theta-E values around 20 K are in support.
More than 10 m/s 0-6 km shear and dynamic lift will be affecting the SW Balkan around Albania, so more organized storms can persist there, which chances of isolated large hail and severe wind gusts.
In general today, from Scandinavia to Central Europe isolated rain or tornado events are possible also outside the level 1 areas in the weak storm motion environment, especially in local convergence zones.
