Daily Analysis

Day 65 — 2026-05-04. No precipitation watershed-wide. Pure recession continues, Day 6 post-Event 8 peak.

1. PRECIPITATION SUMMARY: Zero QPE everywhere. 7-day antecedent continues to decay: Boxley zone 1.55" (was 1.73"), Pruitt zone ~1.15", St. Joe zones avg ~1.5", Harriet zones avg ~1.6". Watershed transitioning out of "wet" into "moderate."

2. GAUGE RESPONSES (recession only):

3. Boxley: 2.43 → 2.31 ft (-0.12 ft over 24 hr) — Hailstone Too Low
4. Ponca: 261 → 209 cfs (-52 cfs) — Optimal
5. Pruitt: 4.36 → 4.04 ft / 278 → 188 cfs (-90 cfs / -0.32 ft) — Low but Floatable (just below 200 cfs threshold)
6. St. Joe: 5.05 → 4.41 ft / 851 → 530 cfs (-321 cfs / -0.64 ft) — Optimal
7. Harriet: 4.97 → 4.48 ft / 1100 → 712 cfs (-388 cfs / -0.49 ft) — Optimal
8. Richland: 1.87 → 1.55 ft (-0.32 ft) — recession

9. Bear Cr: 2.52 → 2.35 ft / 45.3 → 29.3 cfs (-16 cfs) — recession

10. RECESSION RATE TRACKING (Event 8 Day 6, +144 hr post-peak):

11. St. Joe Day 64→65: ~5.8 cfs/hr (was 6.6 prior day) — geometric decay continues
12. Harriet Day 64→65: ~6.9 cfs/hr (was 9.3 prior day) — sharper drop, ~74% of prior rate
13. Pruitt: ~3.8 cfs/hr — now in baseflow regime
14. Bear Creek: ~0.7 cfs/hr — near baseflow

Five consecutive 24-hr recession windows now logged for St. Joe: 33 → 16 → 10 → 6.6 → 5.8 cfs/hr. Each ratio: 0.48, 0.63, 0.66, 0.88. The decay is flattening — reaching baseflow asymptote.

1. PRUITT BELOW 200 CFS: Pruitt dropped to 188 cfs at 20:15, crossing into "Low but Floatable" (100-200 cfs). First time this study Pruitt has dropped to baseflow-class flows. Notable for recreation: still floatable, but lower limb of optimal.

2. TRUE BASEFLOW EMERGING: With 6 dry days following Event 8 and pre-Event 8 baseflow now exceeded on the downside, the watershed is approaching what may be the first observable "true dry-spring baseflow" of the study. Current values represent an important calibration anchor:

3. Pruitt: 188 cfs / 4.04 ft
4. St. Joe: 530 cfs / 4.41 ft
5. Harriet: 712 cfs / 4.48 ft
6. Bear Creek: 29.3 cfs / 2.35 ft
7. Boxley: 2.31 ft

8. Richland: 1.55 ft

9. NO ANOMALIES. Clean recession; geometric decay model holding. Downstream gauges are now well below pre-Event 8 baseline (St. Joe 530 vs 829, Harriet 712 vs 1030 — 36% and 31% below). This strongly confirms the pre-Event 8 baselines were elevated by accumulated wet-spring conditioning and are not representative of true dry baseflow.

Watershed status: Quiet, drying, approaching dry baseflow. 25 days remain. The "moderate antecedent" test window from Day 64 hypothesis is now becoming a "moderate-to-dry" antecedent window — which is itself valuable but a different test regime than originally hoped for.