Concentric circles on meteorological portal images on Tuesday reignited discussions about weather control, but Slovenia's Environment Agency says it's a technical glitch from an Italian radar.
Radar images that on Tuesday, August 11, 2026, showed unusual swirling of storm clouds over Italy, Slovenia, and Croatia, particularly in the Istria region, quickly spread across social media. Around 2:30 PM, users spotted concentric circles on weather portals like Windy and began seeking an explanation for the mysterious phenomenon.
The Slovenian Environment Agency (ARSO) quickly responded to numerous inquiries. Through its official profile on the social network X, ARSO vreme, they explained that the circles do not represent actual precipitation but rather an interference in radar data. "They originate from data from the Fossalon radar in Italy," they stated, adding that the exact cause is unknown, but it is "most likely an error in measurement or data processing."
ARSO elaborated on this phenomenon on its website. The radar measures the atmosphere with an antenna that rotates around a vertical axis at various angles, recording precipitation at different heights above each point on the ground. The computer then extracts the maximum measured value and displays it on the image, meaning what we see is not precipitation at the surface but somewhere above it.
A key factor is also the melting layer of snow at the 0-degree isotherm altitude. "At that altitude, there is an enhanced radar reflectivity due to melting snow," ARSO explains. As differently tilted radar beams intersect the melting zone at various distances, the projections of these maximum echoes onto the ground take the form of concentric circles.
Similar technical artifacts on weather portals regularly fuel conspiracy theories about weather manipulation and secret geoengineering experiments. Meteorologists therefore emphasize that these are common digital imperfections of measurement systems, not mysterious atmospheric phenomena. Although visually striking, these circles are merely a consequence of how radar systems collect and process atmospheric data.
