Rapid Cyclogenesis
Next up on our 25th Anniversary celebration of our favourite weather phenomena is rapid cyclogenesis!
On a calm day, a slight breeze can be gentle and pleasant, rustling leaves and swaying trees. However, on the other end of the scale, wind can be an exceptionally powerful force of nature, reaching speeds of over 200 mph, destroying infrastructure, uprooting trees and devastating landscapes. The difference all comes down to the atmospheric pressure at the surface, with large changes over shorter distances increasing the wind speed (shown by isobars on pressure charts; tighter bars = stronger winds). The most common high wind occurrences we see in the UK are from winter windstorms, low pressure systems that form out in the Atlantic, and then travel over the UK. This is why we have a named storm system, to allow for better preparation and communicate any posing threats and impacts from specific storms.
The process in which these storms form is called cyclogenesis. Relatively speaking, colder air sits closer to the poles, whilst warmer air lies closer to the equator. A stationary front sits between them to stop the air from mixing, but an upper level or topographic disturbance along this front begins the process of cyclogenesis [1, 2]. This creates a slight wave, where the cold air begins to plunge towards the equator behind the wave’s peak and the warm air heads poleward in front of it. The low pressure centre is then formed at the tip of this wave, with a trailing cold front and leading warm front, generating a cyclonic flow of air and a lifting central column. This circling of air causes the high wind speeds, which tend to increase in strength as the system intensifies and the low deepens (reduces in pressure). Cold fronts are denser and move faster than warm fronts, and so they eventually collide, creating an occluded front. This eventually cuts the storm system off from the warm equatorward air, stops the convergence and lifting mechanism in the air column, and the cyclone decays via cyclolysis [1].
Rapid cyclogenesis is this same process but occurs only when the low pressure centre of a storm decreases by 24 millibars over the course of 24 hours. The main driver behind this is the flow of the upper winds (such as the jet stream), which pulls air away from the top of the air column. This forces more air to be sucked in at the base, lowering the pressure rapidly and increasing the circulation of air, and therefore the associated wind speeds [3]. Some of our most damaging storms in recent years have been enhanced by rapid cyclogenesis. Storm Goretti, for example, impacted the UK on the 8th of January 2026 and deepened from 1006 mb at midnight to 969 mb by 18:00, a drop of 37 mb in 18 hours! This storm led to wind speeds of 99 mph being recorded in the Isles of Scilly, and widespread disruption across Cornwall and the South Coast. For more information about this storm, have a look at our news post on this.
High winds are some of the most damaging natural phenomena on our planet, with the likes of these windstorms, more locally based tornadoes or much larger hurricanes in the tropics. Great care and attention therefore needs to be taken to reduce the impact these have on our day to day lives. Knowing when a storm system is undergoing rapid cyclogenesis is incredibly useful, especially for warning the public and lives that could otherwise be in danger can be saved.
If you would like to read more about cyclogenesis, please head to the references used in this article below:
[1] John P. Rafferty (2022). Earth Sciences: cyclogenesis. Available at: https://www.britannica.com/science/cyclogenesis (accessed: 18/05/2026)
[2] American Meteorological Society (2026). Glossary of Meteorology: Lee Cyclogenesis. Available at: https://glossary.ametsoc.org/wiki/lee-cyclogenesis/ (accessed: 19/05/2026)
[3] Met Office (2026). What is a weather bomb? Available at: https://weather.metoffice.gov.uk/learn-about/weather/types-of-weather/storms/weather-bomb (accessed: 18/05/2026)
