Mesoscale Discussion
Valid: Wed 25 Jun 2014 14:00 to Wed 25 Jun 2014 18:00 UTC
Issued: Wed 25 Jun 2014 14:14
Forecaster: BEYER

Several intense storms have formed all the way from southern Slovania to Central Romania showing some suspicous feature of supercell development. Storms are tight to the frontal boundary that is also nicely visible in surface oberservations with more than 25 degree to the south and less than 20 degree to the north. In the line of convective development dewpoints look quite promising with up to about 20 degree. In addition a nice wind shift line can be seen which leads to convergence effects and thus lift. Convergence is best near the surface low. Since it is predicted that this low moves further to the east and should intensify it is quite probable that conditions should become even more favorable in the next hours. Moreover, there is a nice tongue of dry air visible in the WV7.3 channel that should help for further development. Finally ... concerning models ... the upper level and mid level jet is now arriving in the mentioned area what will additionally give enhanced lift.

Good overlap of humidity and instability with (very) high values of DLS (that are also visible in 12 z soundings of Belgrade) will together with the mentioned lift lead to a further enhancement of convective activity. Supercells have the risk of large to very large hail and severe wind gusts. Later on storms may cluster and one or two MCSs may form leading to a risk of severe to hurrican force wind gusts with bowing segments. In addition, since several storms may travel over the same area there is also the possibility for an accumulation of high amounts of rain leading to a risk of flooding (storms travel along a quasistationary surface front). Having in mind high values of LL shear and clockwise turning wind profilest he lowering LCL heights pose an additional threat for tornados that may also be strong given also high values of SRH.

A short wave trough is entering from northwest showing a secondary jet maximum. This should support the development of convection. Looking on surface data one can see a pressure minimum with nice converging winds at the surface over southern parts of Czech Republic. Dewpoints are getting better due to moisture pooling. A disconnected line of thunderstorms is visible over Czech Republic and extreme southeastern Germany that is on its way to travel further southeastward, entering northern Austria and Slovakia. Local area models show an intensification of those storms bringing severe wind gusts as well as locally large hail.