GloFAS Hydrological Products Overview

Reporting points where more forecast information is available. Purple/red/yellow points 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 30-day forecast horizon as shown in the 'Flood summary for days 1-30' layer.

Flood peaks expected within the first 3 days of forecasts are highlighted with black border surrounding the reporting points. This also includes those cases when the peak has already passed with receding flow and the highest probability is on day 1. In addition, when flood peaks are expected beyond 10 days and no floods are expected in the first 10 days (2-year probability <30%), then the reporting points are shaded with a greyed version of yellow/red/purple to indicate the longer lead time.

Numbers denote the percentage of ensemble members exceeding the specific return period within the 30-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.

The 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 1-30 flood summary map colours, without the probability of exceedance information (single colour tone). 

Map showing the exceedance probabilities for the three severity levels of 2- (yellow), 5- (red) and 20-year (purple) return period, with colour tones defined according to the maximum exceedance probability within the 1-3, 4-10, 11-30 and 1-30-day forecast horizon (three subcategories of 30-50%, 50-75% and 75-100% for each of the three severity levels).

The reporting points are defined according to the 'Flood Summary for days 1-30' layer.

Reporting points where ensemble hydrographs and probability (persistence) tables for the high (> 80th percentile) and low (< 20th percentile) flow categories are available, displaying the river flow forecast out to 4 months. Please note: The user is advised to evaluate forecast skill for their particular application.

Maximum probability [%] of high (> 80th percentile) or low (< 20th percentile) river flow during the 4 month forecast horizon. Please note: The user is advised to evaluate forecast skill for their particular application.

Maximum probability [%] of high (> 80th percentile) or low (< 20th percentile) river flow during the 4 month forecast horizon, provided for 305 global basins. Please note: The user is advised to evaluate forecast skill for their particular application.

Probability of ensemble streamflow predictions [%] to exceed a 5-year return period discharge level.

Probability of ensemble streamflow predictions [%] to exceed a 20-year return period discharge level.

Reporting points where more forecast information is available. Purple/red/yellow points denote river catchment outlets where the forecasted probability to exceed the 20-year (purple) / 5-year (red) / 2-year (yellow) return periods is at least 20%. Numbers denote the probability values (percentage of ensemble members exceeding the specific return period). Shape of the markers denotes rising (upward triangle), decreasing (downward triangle), or stagnant (circle) trend of the ensemble mean discharge within the 30-day forecast horizon. The grey squares represent reporting points with no flood signal, i.e. less than 20% probability for exceeding the 2-year return levels.

The flood summary map combines the 2-, 5- and 20-year exceedance probabilities into a category-based information. It shows where the ENS-max (maximum of the ensemble mean discharge) for forecast days 1-3 (4-10 or 11-30 for the other two versions) is >20-year (purple) / 5-20-year (red) / 2-5-year (dark yellow) return period level. Light yellow indicates where the ENS-max is below the 2-year return period value, but there is noticeable probability (>20%) for exceeding the 2-year return period level.

Reporting points where ensemble hydrographs and probability (persistence) tables for the high (> 80th percentile) and low (< 20th percentile) flow categories are available, displaying the river flow forecast out to 4 months. Please note: The user is advised to evaluate forecast skill for their particular application.

Maximum probability [%] of high (> 80th percentile) or low (< 20th percentile) river flow during the 4 month forecast horizon. Please note: The user is advised to evaluate forecast skill for their particular application.

Maximum probability [%] of high (> 80th percentile) or low (< 20th percentile) river flow during the 4 month forecast horizon, provided for 305 global basins. Please note: The user is advised to evaluate forecast skill for their particular application.

Probability of ensemble streamflow predictions [%] to exceed a 5-year return period discharge level.

Probability of ensemble streamflow predictions [%] to exceed a 20-year return period discharge level.