Information about symbols and abbreviations used in Wettergefahren-Frühwarnung
Symbol Meaning Explanation
F Forecast The weather forecasts of extreme events are based on model outputs of various global (and sometimes regional) weather forecast models. A warning will be issued if an exceptional weather situation becomes very likely in several consecutive model runs. An assessment of the upcoming weather situation will be done both objectively on the basis of the model results (exceeding of specified threshold values) and subjectively by experience, estimation and comparison with previous similar weather conditions.
A Analysis The analysis is a review and evaluation of recent exztreme weather events based on weather charts, research and weather recordings.

Symbol Meaning Explanation
Intense Rain Precipitation event with prolonged rain of enormous amounts mostly over a larger area. Exgtensive flooding, major rivers are on flood stage. In hilly terrain also landslides and mudflows occurr.
Intense rain
heavy snow
Precipitation event with prolonged strong rain and possibility of flooding at low altitudes. At higher altitudes heavy snow will occurr causing snow breakages, snowdrifts, avalanches.
Heavy snow Precipitation event with massive snow accumulation on the ground even in lowlands. Streets impassable due to snow, ice, drifting snow, snow breaks.
Icing Precipitation event with rain falling on frozen ground or rain falling at air temperatures below zero degrees. Black ice, collpase of structures (e.g. power lines, trees) due to ice weight. Collapse of transport systems., power outages. Precipitation amounts do not need to be significant.
Tropical cyclones Tropical storms, tropical systems and tropical cyclones (hurricanes, typhoons) of the subtropics when threatening populated islands or shorelines. Damage expected due to hurricane force winds, torrential rain, flooding, landslides, swell, surf, storm surge
Extratropical storms Exceptionally strong low pressure systems embeeded in the westerlies of both hemispheres when affecting populated areas and damage is likely due to wind or storm surge. Also intense lokal wind systems (e.g. Föhn, Mistral, Bora)
Thunderstorms, hail Convective and intense weather events associated with strong rain, hail, hurricane force wind gusts. Usually not affecting large areas, mostly local occurrence and not longlasting.
Tornadoes Mostly in association with strong supercell thunderstorms. Brief in nature, but may cause devastation along its path.
Unusual high temperature Depending on altitude, geographical location, and season unusual high temperatures. Heat waves.
Unusual low temperatures Depending on altitude, geographical location, and season unusual low temperatures. Cold spells. Harsh ice conditions on rivers and sea. Frost.
Flooding Large scale flooding caused by long lasting rain over an large area or entire catchments of major rivers. Major rivers are on flood stage. Sometimes in winter in conjunction with an extreme thaw period.
Drought Extreme dehydration of soils if the rainy season fails or onset comes too late. Even in areas with usually sufficient rain amounts, if there is a long period with no or only a little rain. Damage to agriculture, shipping (low water), drinking water supply.
Bush fire, forest fire Caused by heat, drought, lightning or intentional fire raising. Bush or woods may burn for days, weeks or even months. Houses and other infrastructure may be destroyed.