Mini supercell over Bremen: lightning, heavy rain and storm warning!

Mini supercell over Bremen: lightning, heavy rain and storm warning!

On the night of Sunday, June 15, 2025, a strong storm hit Bremen, Delmenhorst and the surrounding regions. The weather phenomenon, which the German Weather Service (DWD) classified as a mini-supercell, brought heavy rain, stormy gusts and occasional hurricane-like wind peaks. The thunderstorms formed between 11:55 p.m. and 12:25 a.m. During this short period of time, over 1,856 lightning strikes were recorded over Delmenhorst, Ganderkesee and the western part of Bremen. In addition, around 25 liters of rain per square meter fell in the Bremen area between midnight and 12:30 a.m., which is no small feat.

The mini supercell in detail

What exactly is a mini supercell? These special thunderstorms are smaller than their larger siblings, the usual supercells, and are characterized by their rotating updraft. Supercells are known for their ability to produce large hail and even tornadoes. Despite their small size, they can pose similar dangers, experts from Utopia report. These dangerous thunderstorms can cause significant damage and, in the worst case, result in injuries.

On Sunday morning, the Bremen fire brigade reported only ten operations due to the storm. Two of these missions involved flooded basements, while the rest involved clearing up fallen branches. Fortunately, no major danger or chaos was reported by the police in Bremen and Delmenhorst.

DWD warnings and current situation

The weather situation in the region remains tense. Loud Buten and inland Storm “Poly” is moving across the North Sea and could cause additional wind and rain. Warnings from the DWD say that hurricane-like gusts with speeds of up to 110 km/h are possible between midday and evening. In Bremerhaven in particular, gusts of up to 120 km/h are expected, accompanied by thunderstorms and intense rainfall. In Bremen you should be prepared for wind speeds between 65 and 85 km/h and expect 5 to 10 liters of rain per square meter.

Even if the fire brigade and the technical relief organization remain on the ball and monitor the situation, the authorities advise taking precautionary measures. Cars should not be parked under trees and forests or parks should be avoided to be on the safe side.

Citizen preparedness and traffic situation

The citizens of Bremerhaven have taken the warnings to heart. Please do not enter the Bremen Bürgerpark on Wednesday. Deutsche Bahn is also monitoring the weather forecasts and is currently unable to provide any information about possible train cancellations, but is already planning in case the worst comes to the worst. Ferry connections to the East Frisian Islands could also be affected by stormy weather, with cancellations to Norderney and Juist and closed connections to Wangerooge and Spiekeroog.

Overall, the situation remains uncertain, and the storms we have already experienced have shown that even small thunderstorms, such as the recently recorded mini-supercell, can have major impacts. According to the DWD, everyone should take a look at the weather situation and take protective measures if necessary. The information from the DWD is particularly useful in order to get through the next few days safely.

Stay informed and safe during these stormy times!