Baltic Sea

The forecasts serve to ensure the safety and ease of shipping traffic, coastal protection and to inform and warn the public. In addition to seaports with their industry and ferry companies, users include towns and municipalities as well as tourism associations.

Preparation of daily water level forecasts

Twice a day (at 8 a.m. and 2 p.m.) forecasts are made for the following areas:

  • Bay of Kiel
  • Lübeck Bay
  • Area West of Rügen
  • Area East of Rügen
  • Kleines Haff

The data are given as deviations from the mean water level in metres.
A fixed width of 30 cm is specified. In the case of negative surges or storm surges, deviations are possible.

It is possible to obtain further information on each area in the form of hydrographs: Water level forecast Baltic Sea
For 12 gauging stations the current course of the water level and the forecast for 2 days are shown. For selected 5 gauging stations it is possible to compare national and international models.

A forecast map leads for single stations to a 5-day forecast for a rough orientation.

The predictions are based on:

  • Level observations (network of water and shipping authorities),
  • Wind measurements in real time (network of the DWD, water and shipping authorities and internal measuring network coast in Mecklenburg-Vorpommern),
  • Current wind forecasts / model results of the German Weather Service (DWD),
  • Predictions of the operational model of the BSH and other models.

The forecast, taking into account all available information, is produced by the on-duty scientist every day of the year. The service runs 24 hours a day and is divided into office and standby duty.

Distribution of information

The forecasts are distributed by fax, e-mail and FTP download. In addition, all forecasts are published on the Internet at

Warning service

(Low tide

Negative water level deviations from normal mean water (NMW)

  • from 0.6 m: Information for navigation: Navtex warning
  • from 0,75 m: Information about low water levels
  • from 1,00 m: Negative surge warning
  • from 1.00 m below NMW = light negative surge
  • from 1.25 m below NMW = medium negative surge
  • from 1.50 m below NMW = heavy/pronounced negative surge

High water

Positive water level deviations from NMW

  • from 0.75 m: Information about elevated water levels
  • from 1,00 m: storm surge warning
  • from 1.00 m above NMW = slight storm surge
  • from 1.25 m above NMW = average storm surge
  • from 1.50 m above NMW = heavy storm surge
  • from 2.00 m above NMW = very heavy storm surge

The information and warnings are distributed in the following ways:

Via the FACT 24 system, warnings can be issued to interested parties at a charge from a water level of 0.75 m above NMW or 0.75 m below NMW.