About river ice data
During winter periods HHFS daily receives data about river ice conditions from Hungarian and other European hydrological services. River ice reports for Danube, Tisza, Drava rivers and their tributaries are summarized every morning.
The above period typically lasts from 1 December to 31 March, but it can differ from this interval depending on actual weather conditions.
Ice condition data are published in tables and in graphs.
Beside summation of ice reports, HHFS every morning provides ice condition forecasts for Danube and Tisza rivers.
Hungarian Danube stretch (extended up to Bratislava) and Hungarian Tisza stretch are both divided into 4 forecast sections. The forecast model considers the most serious ice phenomena on every section. For example: in case if both ice drift and ice cover occur on a certain section, ice cover will appear in the forecast for this section even if the ice cover is only several hundred meters long which is negligible comparing to the total length of the section. The three main ice conditions on which forecast is based are: free of ice, ide drift and ice cover.
At the issue time of the forecast present and expected ice conditions are published with possible states: free of ice, ice drift and ice cover. In case of ice-free situation water temperatures are also published. For the forecast period tendency of the ice phenomena (weakening or intensifying) is indicated as well.
Lead time of the forecast is 6 days, but it can vary in justified cases. Observations and forecasts always refer to mornings.