Flood Forecast

Last updated: 2026-10-31 07:00:00 SAST
EN ZU XH
Home Lite View

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 0.0176 0.0325 0.0441 0.0522 0.0571 0.0653
Best Match 0.0175 0.0322 0.0426 0.0485 0.0521 0.0623
CMA GRAPES 0.0171 0.0321 0.0453 0.0572 0.0588 0.0576
ECMWF AIFS 0.0203 0.0391 0.0538 0.0650 0.0713 0.0856
ECMWF IFS 0.0173 0.0322 0.0434 0.0496 0.0538 0.0659
ECMWF IFS 0.25° 0.0184 0.0349 0.0467 0.0535 0.0580 0.0716
GFS Global 0.0180 0.0322 0.0429 0.0499 0.0554 0.0649
GFS Seamless 0.0180 0.0322 0.0429 0.0499 0.0554 0.0649
MET Norway 0.0173 0.0322 0.0434 0.0496 0.0538 0.0659
NCEP AI-GFS 0.0192 0.0369 0.0519 0.0635 0.0689 0.0799
NCEP HGEFS 0.0176 0.0319 0.0429 0.0536 0.0600 0.0724
UKMO Global 0.0190 0.0352 0.0490 0.0598 0.0686 0.0789
Based on 7,993,728 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.