GloFAS Hydrological Products Overview

Reporting points where more forecast information is available. Coloured reporting points (triangle symbol) denote expected floods to exceed 20-year (purple), 5-year (red) or 2-year (yellow) return period by at least 30%, according to the highest probability of exceedance over the 15-day forecast horizon as shown in the 'Flood summary for days 1-15' layer.

Reporting point symbols are displayed in three ways, depending on the lead time of the expected peak in the forecast:

• 1-3 days: Reporting Points with flood peaks expected within the first 3 days of forecasts are highlighted with a solid black border. This also includes those cases when the peak has already passed with receding flow and the highest probability is on Day 1. 
• 4-10 days: Reporting Points with flood peaks expected within 3-10 days of forecasts have a solid grey border. 
• 10-15 days: Reporting points are displayed with a greyed-out version of yellow/red/purple symbols to indicate longer lead times. The greyed-out version of the reporting points is shown when flood peaks are expected beyond 10 days and no floods are expected in the first 10 days (where 2-year probability <30%).

Numbers on the reporting point symbols denote the percentage of ensemble members exceeding the specific return period within the 15-day forecast horizon for reporting points that have floods in the first 10 days (2-year probability above 30%).

The shape denotes rising (upward triangle), decreasing (downward triangle), or stagnant (circle) trend of the ensemble median discharge within the forecast horizon.

Grey squares represent reporting points with no forecasted flood (i.e. less than 30% probability for the river discharge to exceed the 2-year return period flood threshold).

The reporting point marker colours are consistent with the days 1-15 flood summary map colours, without the probability of exceedance information (single colour tone). 

Probability of ensemble streamflow predictions [%] to exceed the 5-year return period discharge level at any point in the 15-day forecast horizon.

Probability of ensemble streamflow predictions [%] to exceed the 20-year return period discharge level at any point in the 15-day forecast horizon.

The flood summary map combines the 2- (yellow), 5- (red) and 20-year (purple) exceedance probabilities into categorical information. Each of the three flood severities is further divided into three subcategories based on the maximum exceedance probability within the 15-day forecast horizon (30-50%, 50-75% and 75-100%). There are four flavours, based on the period, one map for the first 3 days (days 1-3), one for days 4-10, one for beyond 10 day (days 11-15) and one for the whole 15-day forecast period (days 1-15). The map for days 1-15 is used in the definition of the reporting points. The reporting point marker colours (severity category) are based on this days 1-15 map and also the dynamic reporting points are generated using this information.

The reporting points are defined and characterised for flood signal type according to the 'Flood Summary for days 1-15' layer.

River flow anomaly and uncertainty information for the next 7 months, based on monthly average discharge, for all river pixels over 1000 km². Detailed information is provided in a pop-up window for reporting points (fixed and basin-representative) with the forecast signal and probability evolution, including the model climatology and water balance of the recent past.

Further information about the methodology and products is provided at CEMS-flood sub-seasonal and seasonal forecast product generation methodology.

River flow anomaly and uncertainty information for the next 7 months, based on monthly average discharge, aggregated over 942 predefined river basins.

Further information about the methodology and products is provided at CEMS-flood sub-seasonal and seasonal forecast product generation methodology.

River flow anomaly and uncertainty information for the next 5-6 (depending on which day of the week the model runs) calendar weeks, based on weekly average discharge, for all river pixels over 1000 km². Detailed information is provided in a pop-up window for reporting points (fixed and basin-representative) with the forecast signal and probability evolution, including the model climatology and water balance of the recent past.

Further information about the methodology and products is provided at CEMS-flood sub-seasonal and seasonal forecast product generation methodology.

River flow anomaly and uncertainty information for the next 5-6 (depending on which day of the week the model runs) calendar weeks, based on weekly average discharge, aggregated over 942 predefined river basins.

Further information about the methodology and products is provided at CEMS-flood sub-seasonal and seasonal forecast product generation methodology.