Daily Analysis

Pre-analysis (per-gauge first/max/last): - Boxley: first 2.36 ft @ 00:00, max 2.36 ft @ 00:00 (multi-tie through ~01:15), last 2.27 ft @ 23:30. Pure recession. - Ponca: first 209 cfs @ 00:00, max 209 cfs @ 00:00 (sustained early), last 190 cfs @ 23:30. Pure recession. - Pruitt: first 4.01 ft / 180 cfs @ 00:00, max 4.02 ft @ 00:30 / 183 cfs @ 00:30, last 3.93 ft / 158 cfs @ 23:30. Slight noise-level early bump within recession. - St. Joe: first 4.30 ft / 482 cfs @ 00:00, max 4.30 ft / 482 cfs @ 00:00, last 4.12 ft / 409 cfs @ 22:45. Pure recession. - Harriet: first 4.38 ft / 642 cfs @ 00:00, max 4.38 ft / 642 cfs @ 00:00, last 4.23 ft / 542 cfs @ 22:45. Pure recession. - Richland: first 1.46 ft @ 00:00, max 1.46 ft @ 00:00, last 1.37 ft @ 23:00. Pure recession overall, but a small bump 1.39→1.42 ft between 17:30-18:30 (+0.03 ft, then back). - Bear Creek: first 2.32 ft / 27.0 cfs @ 00:00, max 2.32 ft / 27.0 cfs @ 00:00, last 2.26 ft / 22.9 cfs @ 23:15. Pure recession.

1. PRECIPITATION SUMMARY

Zero zone-averaged QPE today across all 8 zones. Yesterday's late-night Boxley/Ponca pulse (zone QPE 0.181"/0.125", peak ~03:02 UTC = ~22:02 CDT 5/8) was the last forcing input. 7-day antecedents at headwater HUC12s nudged up modestly (Boxley 1.27→1.45", Richland HW 1.17→1.24") reflecting that pulse still inside the trailing window, while St. Joe and Harriet zone HUC12s remain near 0.3-0.5" (drying continues there).

2. GAUGE RESPONSES

All seven gauges in pure recession through Day 70. No significant rises.

• Boxley: 2.36 → 2.27 ft over 23.5 hr (-0.09 ft). Now BELOW Day 65 dry-spring baseline (2.31). The Day-69 hypothesis that "pool drain takes 3+ days" is confirmed: ~107 hr post Day-66 peak (3.16 ft @ 12:15 D66) the gauge has finally sunk below pre-event baseline. The Day 68 sub-threshold pulse (0.181" zone) produced no detectable response at Boxley — this confirms the ~0.4-0.5" dry detection threshold; 0.18" is well below it.
• Ponca: 209 → 190 cfs (-19 cfs). Now below Day 65 baseline (206 cfs). Same conclusion — sub-threshold pulse failed to register; CFS now in the 150-200 "Low but Floatable" band actually... 190 is in the 150-200 zone. Recreational note: Ponca has dropped from "Optimal" (>200) into "Low but Floatable" today.
• Pruitt: 4.01 → 3.93 ft, 180 → 158 cfs (-0.08 ft / -22 cfs). Well below Day 65 baseline (4.04 ft / 188 cfs). The within-day max of 4.02/183 at 00:30 is just yesterday's pre-existing level. Pruitt CFS = 158 — still in Optimal (100-2000), but trending toward Low-Floatable threshold (100).
• St. Joe: 4.30 → 4.12 ft, 482 → 409 cfs (-0.18 ft / -73 cfs over 22.75 hr ≈ 3.2 cfs/hr). Continued geometric decay: 6.96 (D68) → 5.1 (D69) → 3.2 (D70) cfs/hr. Now well below Day 65 baseline (530 cfs).
• Harriet: 4.38 → 4.23 ft, 642 → 542 cfs (-0.15 ft / -100 cfs over 22.75 hr ≈ 4.4 cfs/hr). Sequence: 6.3 (D69) → 4.4 (D70) cfs/hr. Now well below Day 65 baseline (712 cfs).
• Richland: 1.46 → 1.37 ft, with a small intra-day bump 1.39→1.42 between 17:30-18:30 (+0.03 ft). This bump occurred with zero today-QPE in Richland zone — possibly residual interflow from the Day-68 sub-threshold pulse propagating through karst, or noise. Magnitude is below my noise threshold for confident attribution.
• Bear Creek: 2.32 → 2.26 ft, 27.0 → 22.9 cfs. Below Day 65 baseline (2.35 ft / 29 cfs).

3. RAINFALL-RESPONSE PAIRS

Sub-threshold non-detection — Day 68 Boxley/Ponca pulse: Zone QPE Boxley 0.181"/Ponca 0.125", peak ~22:02 CDT D68. By end of D70 (~50 hr after pulse), neither gauge produced any deviation from the Event-9 recession trajectory. Confirms detection threshold ~0.4-0.5" zone-avg dry for Boxley (per hypothesis #9). 0.18" is firmly sub-threshold. No transfer ratio computable.

No new lag/transfer pairs to compare with priors today.

4. DOWNSTREAM PROPAGATION

No propagation event today. All five mainstem gauges in synchronous recession.

5. MULTI-DAY EVENTS — Event 9 recession Day 5

Day 70 = ~106 hr post Event-9 forcing peak (~10:00 D66). The recession at all five mainstem gauges is now well past the Day-65 "dry-spring baseflow anchor" — confirming the Day-69 refinement that the Day-65 floor was a moment in a continuing seasonal decline rather than a stable baseline.

St. Joe recession ledger: - 22:30 D67 peak: 4.92 ft / 780 cfs - end D68: 4.59 ft / 613 cfs (24 hr: -167 cfs, 6.96 cfs/hr) - end D69: 4.32 ft / 491 cfs (24 hr: -122 cfs, 5.1 cfs/hr) - end D70: 4.12 ft / 409 cfs (24 hr: -82 cfs, 3.2 cfs/hr)

Geometric decay (ratio ~0.65-0.75 per 24 hr) is now firmly established. This is faster fractional decay than Event-8 wet recession (33→16→10→6.6→5.8 ratio ~0.55→0.6→0.66→0.88), suggesting dry recession converges to the seasonal baseflow trajectory more rapidly once near baseline.

Harriet recession: 917→816→649→542 cfs across D68-end through D70-end. ~6.3 then ~4.4 cfs/hr — consistent with the geometric pattern.

6. ANOMALIES OR SURPRISES

• Boxley pool fully drained. 2.27 ft today is 0.04 ft below the Day-65 "dry-spring baseflow" of 2.31 ft. The pool-drain timeline is now fully resolved: Day-66 peak (3.16) → Day-69 nearly back (2.36, +0.05 above Day-65) → Day-70 below Day-65 baseline. Total pool drain time from peak ≈ 4 days. Refines hypothesis #5 from "3+ days" to "~4 days for full drain."
• Day-68 sub-threshold pulse (Boxley 0.18", Ponca 0.13") produced zero detectable signal at any of the seven gauges. This is a clean non-detection that strengthens the ~0.4-0.5" Boxley detection threshold.
• Ponca crossed into "Low but Floatable" (150-200 cfs) today, ending at 190 cfs. First sustained sub-Optimal reading at Ponca since the dry stretch in late April pre-Event 8. Recreational implication for paddlers.
• Richland 17:30-18:30 +0.03 ft micro-bump with zero local QPE — most likely sensor noise (the gauge oscillates ±0.01-0.02 ft at this stage), but noted in case it recurs. Not flagged as significant.