Storm Forecast
Valid: Tue 10 Jul 2018 06:00 to Wed 11 Jul 2018 06:00 UTC
Issued: Mon 09 Jul 2018 22:18
Forecaster: DAFIS

A level 1 was issued for parts of Germany, Switzerland, Austria, Czech Republic, Slovakia and Poland mainly for severe wind gusts, excessive precipitation and tornadoes, and to a lesser extent large hail.

A level 1 was issued for parts of Ukraine, Moldova, Romania and Bulgaria mainly for excessive precipitation and severe wind gusts.

SYNOPSIS

The ridge which was extending from W Mediterranean towards the North Sea is collapsing, and several troughs travel above the European domain. There is an ongoing DMC event in NE Spain due to a shortwave trough which will weaken by the morning of Tuesday 10/07. Another trough is found over the Balkans where many thunderstorms will keep on forming, a weaker short-wave trough is over N Italy and moves fast south and the most intense trough is expected to cross Denmark and Germany on Tuesday, carrying strong PV. The biggest part of continental Europe will experience thunderstorms on Tuesday.

DISCUSSION

.... Central Europe ....

An unseasonably cold air-mass is approaching from the north, bringing large amounts of positive vorticity and has a belt of severe winds in the mid-levels, increasing the DLS to 15-20 m/s. Even though limited diurnal heating is expected due to cloudiness, we expect several storms that may become severe, especially in W Germany and W Poland where LL moisture is more pronounced. The main threat will be severe wind gusts and large amounts of small hail. NWP models do not forecast MLCAPE more than 400-800 J/Kg, so large hail events should be limited. Veering winds and LLS create LL helicity which increases the probability of tornadic events, even though as mentioned, CAPE will not be pronounced, some landspouts are not ruled out.

.... East Balkans ....

As the cut-off low moves NE, several convergence zones and abundant synoptic lift will create numerous storms in the Balkans. A level 1 has been placed where the CAPE-shear is more pronounced and where LL moisture is maximized. Moist air masses from the Black Sea can lead to excessive precipitation events and strong cold pools may produce severe wind gusts.