The new warning levels are conversions of previous levels into to the new reference system. This means that they are not significantly different from the previous levels. Thus, sea levels that trigger warnings are the same as they were before. However, due to geographical variances in mean sea level long the Swedish coast, the levels are now more differentiated than before.
New classifications for low sea levels
In conjunction with the transition to a new reference system, SMHI has changed the classification for low sea levels along the Swedish coast. What was previously class 2-warnings will now be class 1-warnings. This is because the impacts of low sea levels along the coast better correspond to SMHI’s definition of class 1-warnings. Exceptions have been made for the Sound, the Belts and the South-Western Baltic, where heavily trafficked and partly shallow fairways justify the use of two classifications (i.e. class 1 and class 2).