← 2026-05-22  |  2026-05-24 →

Cossatot River — Daily Analysis: 2026-05-23

Classification: correct Confidence: Model confidence remains stable. The successful handling of a saturated, multi-band event reinforces the validity of the current coefficients, particularly for headwaters (Bands 4-5).

Event Summary

The model accurately predicted a 1.3 ft rise driven by widespread moderate rainfall on saturated soils, achieving high magnitude accuracy (1.9% error) despite a slight timing offset.

Prediction vs Actual

Metric Predicted Actual Error
Peak height 4.22 ft 4.14 ft +0.08 ft
Total rise 1.3 ft

Band Contributions

Band Precip Predicted Rise Intensity Moisture
4 0.37" 0.31 ft MODERATE SATURATED
5 0.31" 0.12 ft LIGHT SATURATED

Empirical Forecast

Headline: Watch — Recent rainfall is in the lower-bound range preceding rises to MEDIUM Settled outcome: verified (reached medium) LLM said headline was correct: True Notes: The empirical model correctly predicted a rise to the MEDIUM tier, which was verified by the actual gauge outcome.

Analysis

Today's event featured a complex hydrograph driven by significant rainfall across all bands (0.37" in Band 4, 0.31" in Band 5) and zero gauge precipitation. The physics-based model correctly identified the contribution from distant headwaters (Bands 4 and 5) and applied the SATURATED moisture multiplier (2.0). The predicted peak of 4.22 ft was extremely close to the actual peak of 4.14 ft, with an error of only 1.9%. The broad shape of the hydrograph (23-hour duration) was consistent with the widespread nature of the rainfall and saturated antecedent conditions, which slowed peak arrival.

The primary deviation was a timing error of 0.9 hours, with the prediction peaking later than the actual gauge maximum. This may suggest that under saturated conditions, the initial response time is slightly faster than the standard lag parameters, or that the dispersion model slightly over-smoothed the early rise. However, given the high accuracy of the magnitude and the complexity of the multi-band event, the prediction is classified as correct. No coefficient adjustments are necessary as the model performance was within acceptable bounds.

Coefficient Adjustments

No changes made.

Notes

Model confidence remains stable. The successful handling of a saturated, multi-band event reinforces the validity of the current coefficients, particularly for headwaters (Bands 4-5).

← 2026-05-22  |  2026-05-24 →