- Offizieller Beitrag
Am Freitag und in der Nacht zum Samstag sind in Teilen von Thüringen Schauer und Gewitter zu erwarten.
Hauptgefahren sind Blitzschlag und besonders Starkregen mit Überflutungsgefahr. Durch langsame Verlagerung und hohem Gehalt an niederschlagbarem Wasser drohen örtlich Überflutungen/Schlammlawinen.
Grober Ablauf: Bereits mittags über den Bergen erste Entwicklungen. Von Osten her im Bereich der Tiefdruckrinne ebenfalls auflebende Konvektion, mit retrograder Entwicklung (rückwärtsziehend, in diesem Fall nach Westen anbauend). In der Nacht zum Samstag ist teils noch längerer Stark- und Dauerregen möglich, wo die Gewitterreste des Tages liegen und ausregnen. In Regionen, die zu erst von Gewittern und dann von von konvektivem Regen getroffen werden, sind die höchsten Regensummen zu erwarten. Die Gefahr von Überflutungen ist in diesem Bereich am größten. Wo genau diese Bereiche liegen, wird erst sehr kurzfristig nach Entstehung der Gewitter zu sehen sein.
Karten (2): Modellzentrale
Storm Forecast
Valid: Fri 26 Aug 2022 06:00 to Sat 27 Aug 2022 06:00 UTC
Issued: Thu 25 Aug 2022 21:21
Forecaster: PISTOTNIK
A level 1 is issued for Denmark, Germany, Switzerland, the French Alps, Italy, Austria and the Czech Republic as well as for Greece and W Turkey mainly for excessive convective precipitation.
SYNOPSIS
A late summer pattern has established with calm and very warm to still hot conditions across most of Europe. At the northern flank of a slowly filling mid-level low over SE Europe, weak but persistent warm air advection from easterly direction covers most of the continent. The polar front is displaced to the far north and only grazes Scotland and Scandinavia.
DISCUSSION
... central Europe, W Balkans, Italian and Greek mainland, Crete, W Turkey ...
A large plume of hot continental air with steep lapse rates spreads westward across central Europe and the Balkans and eventually also approaches Italy, Greece and W Turkey. The trapping of low-level moisture sustains 2m dewpoints often in the upper tens and locally even around 20C, allowing CAPE between 500 and 1500 J/kg to form after some daytime heating.
Scattered, mostly daytime-driven storms are expected over mountains and generally in the convergent wind field over central Europe. Weak vertical wind shear keeps convection disorganized and the main hazard confined to excessive rain, though isolated hail and wind events are not ruled out in maturing stages of the strongest pules storms.
Upscale growth into several large clusters is possible towards evening esepcially in Germany and Bohemia, where a level 2 was considered. However, storm coverage remained much lower than expected in Thursday despite already plentiful CAPE and only weak capping evident in the soundings.
A lack of synoptic lift (despite the background of warm air advection) could keep convective initiation again rather sluggish on Friday or even make it regionally fail, which is also reflected by a considerable spread of precipitation signals in the forecast models. Therefore, a broad level was kept for now, but it is worth mentioning that level 2 conditions could yet arise in some regions, especially if gust fronts become strong enough to initiate a "snowball effect" of numerous secondary storms.