The Black Tide was a natural disaster that hit north-west Europe on February 9, 2011. A force 13 storm pushed the poisoned waters of the North Sea against the coasts and up the Elbe river, breaking dams and flooding large areas (including parts of the city of Hamburg). It killed thousands and displaced millions in the affected areas of Denmark, Germany, the Netherlands, Norway and the UK.
- The original Beaufort scale was an attempt to classify storm wind speed based on observations of water conditions, and had 12 force levels. In 1946 the Beaufort scale was revised to be based on an empirical formula: V = 0.836 B3/2 m/s. So a force 13 storm has wind speeds of 36.9 – 41.5 m/s (133–149 kph).
- As currently used in much of the world, the reported scale still stops at 12; and all storms with wind speeds above 32.6 m/s (117 kph) are simply classified as force 12. However many western Pacific countries use the empirically calculated scale through force 17.
- As a comparison, 2005's Hurricane Katrina—which did not happen in Shadowrun's timeline, since they diverged circa 1990—topped out in open water at force 20 (using the formula) and was force 12 when it made landfall.
- Deutschland in den Schatten II, 9