HPstormen

HPstormen is a term used in meteorology to describe a recurring pattern of severe weather in the North Atlantic and surrounding regions. It involves the rapid development of a cluster of storm cells within a broader low-pressure system, producing strong winds, heavy precipitation, and sometimes coastal flooding. The phenomenon is notable for its mobility, as the large storm system can travel long distances while maintaining its overall structure through successive regions.

The term HPstormen was coined by meteorologists in the Nordic region in the early 2010s to describe this recurring storm pattern. The name is descriptive rather than an indication of a single formation mechanism, and it is used primarily in regional weather discussions and research papers.

Formation of HPstormen typically begins with a deepening low-pressure trough and an amplified jet stream over the North Atlantic. Cool, dry air and warm, moist air collide, triggering rapid convective development. As the system evolves, multiple storm cells organize into squall lines and then into a broad, mobile cyclone with a central low and trailing rainfall bands.

Geographically, HPstormen most often affects Western Europe, including the United Kingdom, Norway, Sweden, Denmark, the Netherlands, and parts of Germany, with impacts extending to the North Sea coast. Impacts can include damaging winds, heavy rainfall, flooding, coastal erosion, and disruption to transport and power networks.

Forecasting HPstormen relies on numerical weather prediction, satellite and radar data, and surface observations. Ensemble forecasts and high-resolution models help improve track and intensity predictions, though uncertainties remain in timing and exact path. Ongoing research examines climate variability, regional sensitivity, and the potential influence of sea surface temperatures on the frequency and intensity of HPstormen.