Flood Forecast

Last updated: 2026-11-06 20:00:00 SAST
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Weather Models

Statistics

Water Level
Min—
Mean—
Max—
Rainfall
Total—
Max Hourly—
Mean Hourly—
Wet Hours—

Forecast Accuracy

MAE (m) by forecast horizon
Model 1-6h 7-12h 13-24h 25-48h 49-72h 73h+
Ensemble Mean 0.0846 0.0811 0.0827 0.0809 0.0820 0.0936
Best Match 0.0882 0.0847 0.0864 0.0843 0.0897 0.0999
CMA GRAPES 0.0871 0.0862 0.0892 0.0899 0.0930 0.1058
ECMWF AIFS 0.0867 0.0827 0.0828 0.0822 0.0818 0.0923
ECMWF IFS 0.0881 0.0846 0.0863 0.0845 0.0893 0.0992
ECMWF IFS 0.25° 0.0871 0.0847 0.0864 0.0869 0.0883 0.0968
GFS Global 0.0922 0.0902 0.0915 0.0899 0.0880 0.1081
GFS Seamless 0.0922 0.0902 0.0915 0.0899 0.0880 0.1081
MET Norway 0.0881 0.0846 0.0863 0.0845 0.0893 0.0992
NCEP AI-GFS 0.0889 0.0862 0.0861 0.0831 0.0828 0.1007
NCEP HGEFS 0.0850 0.0820 0.0839 0.0847 0.0854 0.0971
UKMO Global 0.0934 0.0927 0.0959 0.0915 0.0964 0.1078
Based on 720,900 prediction-observation comparisons (all-time). Updates every hour as new observations verify past predictions.
How is this calculated?

Each hour, the system generates water level predictions for the next 7 days using each weather model's rainfall forecast. Once real observations come in, the predicted values are compared against what actually happened. MAE (Mean Absolute Error) is the average difference between predicted and observed levels — lower is better. Columns group predictions by how far ahead they were made: a "1-6h" prediction is easier to get right than a "73h+" one. Values are colour-coded: green < 0.02m, yellow < 0.05m, orange < 0.1m, red ≥ 0.1m.