Flood Forecast

Last updated: 2026-11-06 19:00:00 SAST
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Weather Models

Statistics

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Max Hourly—
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Forecast Accuracy

MAE (m) by forecast horizon
Model 1-6h 7-12h 13-24h 25-48h 49-72h 73h+
Ensemble Mean 0.0328 0.0383 0.0430 0.0486 0.0485 0.0523
Best Match 0.0336 0.0416 0.0479 0.0510 0.0528 0.0583
CMA GRAPES 0.0311 0.0371 0.0439 0.0558 0.0593 0.0501
ECMWF AIFS 0.0359 0.0417 0.0445 0.0485 0.0480 0.0553
ECMWF IFS 0.0336 0.0416 0.0479 0.0510 0.0528 0.0583
ECMWF IFS 0.25° 0.0337 0.0384 0.0438 0.0473 0.0476 0.0537
GFS Global 0.0343 0.0402 0.0444 0.0532 0.0514 0.0540
GFS Seamless 0.0343 0.0402 0.0444 0.0532 0.0514 0.0540
MET Norway 0.0336 0.0416 0.0479 0.0510 0.0528 0.0583
NCEP AI-GFS 0.0352 0.0391 0.0445 0.0485 0.0467 0.0602
NCEP HGEFS 0.0352 0.0404 0.0437 0.0481 0.0488 0.0510
UKMO Global 0.0348 0.0429 0.0497 0.0531 0.0577 0.0776
Based on 967,992 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.