An ion storm in the Delta Quadrant in 2375.
An ion storm (also called an ionic storm or ionic front) is a type of magnetic storm which contains ionically charged particles, traveling at thousands of kilometers an hour. Both planetary and spaceborne ion disturbances can intensify to the point where navigation is dangerous, and transporter use all but impossible. At higher levels ion storms can damage or destroy spacecraft.
Ion storms are prevalent in the Denorios belt and have been since at least the 22nd century. In the Bajoran year 9174, Akorem Laan's lightship was caught in an ion storm there and was severely damaged. (DS9: "Explorers", "Accession")
The Kalandra star system has many ion storms. In 2375, Captain Benjamin Sisko and General Martok expressed their concerns the storms would reveal the Federation Alliance starships to the Dominion. (DS9: "The Emperor's New Cloak")
The Panora system also has constant ion storms. (DS9: "For the Uniform")
In the 23rd century, Constitution-class starships were equipped with an ion pod, allowing the vessels to acquire data in conditions that defeated their conventional sensor platforms. Starships traversing ion storms were buffeted by the storms "weather" effects and subjected to tremendous hull pressures and stress. Starfleet used the measurement of a storm's relative effect on the ship as a supplementary data point to judge the intensity of an ion storm, and hazards it posed. Minor but noticeable "natural vibrations" were labeled Force-2 on an incremental scale. Above Force-7, the starship was at increased risk and subject to the captain's call for red alert status. (TOS: "Court Martial")
The quasar-like electromagnetic phenomenon Murasaki 312 ionized an entire sector, including four solar systems in 2267. (TOS: "The Galileo Seven")
Later in 2267, the interference of an ion storm around Halkan homeworld caused a transporter malfunction that exchanged Captain Kirk and three of his officers with their counterparts from an alternate reality, placing them in the mirror universe. (TOS: "Mirror, Mirror")
The surface of Mab-Bu VI was ravaged by ionic cyclones and electromagnetic storms. (TNG: "Power Play")
In the early 2350s, an ion storm struck an area on Invernia II. Richard and Julian Bashir sought shelter from it. (DS9: "Melora")
In late-2371, Major Kira Nerys claimed an ion storm was disrupting Admiral Toddman's subspace transmission, but this was not true. (DS9: "The Die is Cast")
In 2374, Morn faked his death in an ion storm. His cargo ship was supposedly caught in one. (DS9: "Who Mourns for Morn?")
Ionic storms above level 8 are a threat to Intrepid-class starships. The USS Voyager encountered level 7 and level 8 storms in the Delta Quadrant in 2375. (VOY: "Once Upon a Time")
A Borg sphere was heavily damaged by an ion storm in 2375. As a result, it was chosen by the Voyager crew to be the target of a raid to steal a transwarp coil. (VOY: "Dark Frontier")
In 2379, Captain Picard used a nearby ion storm as an excuse to take the shuttle Argo to the surface of Kolarus III in search of positronic net signals. (Star Trek Nemesis)