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). 

Return period exceedance map showing the highest return period level exceeded in the AIFS Single forecast at any point in the 15-day forecast horizon for river cells above 250km². Coloured pixels show where the maximum river discharge exceeds the 2-year flood threshold (yellow), the 5-year (red), and the 20-year (purple). Pixels where the 2-year river discharge flood threshold is below 0.1 m3/s are not coloured.

Probability of ensemble river discharge [%] to exceed the 5-year return period level at any point in the 15-day forecast horizon. River cells above 250km² are shown by colouring (shades of red), if the 2-year river discharge flood threshold exceeds 0.1 m3/s.

Probability of ensemble streamflow predictions [%] to exceed the 20-year return period discharge level at any point in the 15-day forecast horizon. River cells above 250km² are shown by colouring (shades of red), if the 2-year river discharge flood threshold exceeds 0.1 m3/s.

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. River cells above 250km² are shown, if the 2-year river discharge flood threshold exceeds 0.1 m3/s.

The reporting points are defined and characterised for flood signal type according to the 'Flood Summary for days 1-15' layer. River cells above 250km² are shown by colouring (shades of red), if the 2-year river discharge flood threshold exceeds 0.1 m3/s.

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 monthly averaged forecast hydrograph (box-plots), water balance of 6 past months and model climatology reference for every lead times, and a probability evolution table with the most recent 7 seasonal forecast runs.

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 for each lead time, 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 weekly averaged forecast hydrograph (box-plots), water balance of 6 past weeks and model climatology reference for every lead times, and a probability evolution table with the most recent (34-40, depending of the day of the week) forecast runs.

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.