PRE-ANALYSIS (per-gauge facts, all timestamps CDT):
| Gauge | (a) first | (b) max | (c) last | (d) intraday low | (e) low→peak rise |
|---|---|---|---|---|---|
| Boxley (ft) | 2.11 @00:00 | 2.11 @00:00 | 2.02 @23:30 | 2.02 @~21:45→23:30 | none (monotonic recession; only ±0.01 seepage jitter) |
| Ponca (cfs) | 109 @00:00 | 109 @00:00 | 97.8 @23:30 | 97.8 @19:45→end | none (monotonic) |
| Pruitt (cfs) | 200 @00:00 | 203 @00:30 | 166 @23:30 | 166 @16:00 | +8 cfs (166→174 @17:45); height 3.89→3.92, +0.03 ft — recession-tail noise |
| St. Joe (cfs) | 791 @00:00 | 791 @00:00 | 666 @22:45 | 666 @22:45 | none (monotonic); height 4.94→4.70 |
| Harriet (cfs) | 1100 @00:00 | 1110 @00:15 | 933 @22:45 | 933 @22:45 | none (monotonic); height 4.98→4.77 |
| Richland (ft) | 1.42 @00:00 | 1.42 @00:00 | 1.33 @23:00 | 1.33 @22:00 | +0.01 ft wobble @11:45 — PRECEDES the 17:02 QPE peak → recession-tail noise |
| Bear Cr (cfs) | 45.3 @00:00 | 46.4 @00:15 | 38.0 @23:15 | 37.1 @23:00 | +0.01 ft / +1.1 cfs wobble @09:30 — PRECEDES the 12:02/17:02 QPE peaks → noise |
(f) QPE-peak attribution check: Today's only non-trivial QPE is in the Richland zone — Headwaters Richland (0306) 0.049" / 0.038"/hr peak @17:02, Falling Water (0307) 0.058" / 0.025"/hr @16:02. The Richland gauge's only within-day uptick (+0.01 ft @11:45) occurs ~5 hr before the 17:02 QPE peak, so it cannot be attributed to that rain — it is karst/recession-tail jitter. No valid rainfall-response pair exists today at any gauge. Every gauge's daily max = its 00:00 reading (or +1 step of resolution noise), i.e. pure recession.
1. PRECIPITATION SUMMARY Trace, distributed afternoon rain — basin-max 24-hr QPE 0.054" (Richland zone), the highest single-day total since Day 108 but still an order of magnitude below detection. Loose centers: Richland headwaters (Falling Water 0307 0.058"/0.025"/hr; Headwaters Richland 0306 0.049"/0.038"/hr @17:02), Bear (0403 0.033"/0.012"/hr), and scattered ungauged south (Davis 0506 0.032", Long Cr 0505 0.018"). St. Joe own-zone 0.007" (Headwaters Big Cr 0302 0.020", Outlet Richland 0308 0.022"). Pruitt/Harriet zones essentially zero (0.001–0.002"). Zone averages all <0.06" — far below the ~0.22"+ receding-basin absorbed-pulse floor.
Antecedent note (important context shift): the 7-day cumulative has now rolled past the Event-20 rainfall (Days 105–106), so antecedent values have collapsed from ~4.5–4.7" (Richland, two days ago) to 0.57–0.98" today. The basin is transitioning from "wet" to "moderate/drying" antecedent even while gauges remain in flood-limb recession.
2. GAUGE RESPONSES Zero attributable response anywhere — Event-20 flood-limb recession Day 8, a clean non-detection-on-recession day. Every mainstem and tributary gauge is in pure recession (daily max = 00:00 reading). The Pruitt evening wobble (+8 cfs / +0.03 ft @17:45) and the Richland/Bear morning ±0.01 ft ticks all precede or are sub-resolution relative to their candidate QPE peaks → recession-tail noise per the timing-discipline rule.
Status snapshot (Day-113 end): - St. Joe 666 cfs / 4.70 ft — solidly mid-Optimal into recession Day 8; now well below yesterday's 796 and clearly below the Event-19 Day-104 ~800-cfs reference. - Harriet 933 cfs / 4.77 ft — solidly mid-Optimal; persistent limb offset confirmed again (~267 cfs above St. Joe). - Pruitt 166 cfs / 3.89 ft — Low-but-Floatable (crossed 200 yesterday); descending but still far from the 100-cfs Too-Low boundary. At 3.89 ft this is just below the ~3.7-ft low-stage-unreliable threshold edge — cfs reasonably trustworthy here but watch as stage drops further. - Ponca 97.8 cfs — solidly Too Low (below 100 now). - Boxley 2.02 ft — seepage (~0.0038 ft/hr), below all recreational thresholds and below pre-event baseline. - Richland 1.33 ft / Bear 37.1 cfs (2.36 ft) — new post-event lows, deep in pre-event-baseline overshoot.
3. RAINFALL-RESPONSE PAIRS None. Today's forcing (0.054" zone-max, 0.038"/hr peak) is far below the receding-basin detection floor established Days 104/108/110/111 (≥~0.22" zone-average). This is consistent with — and slightly strengthens — Open Q10: even with a 0.038"/hr Headwaters-Richland burst inside Richland's own zone, the gauge did not register. No transfer ratio or lag is computable. (Cross-event comparison is moot on a non-detection day.)
4. DOWNSTREAM PROPAGATION None — no coherent pulse to route.
5. MULTI-DAY EVENTS Day 8 of the Event-20 recession limb (Days 107–113). St. Joe/Harriet have now held Optimal continuously since re-entry on Day 107 — an 8-day Optimal window and counting on the lower mainstem from the study-record trunk flood. Recession-rate points extend the dQ/dt-vs-Q curve into the deep baseflow band: - St. Joe ~5.5 cfs/hr @~730 cfs (791→666 over 22.75 hr); stage ~0.0105 ft/hr. - Harriet ~7.3 cfs/hr @~1020 cfs (1100→933 over 22.75 hr); stage ~0.0088 ft/hr.
These sit slightly below the Day-112 points (~7 / ~9.3 cfs/hr) and remain within/under the ~10–15 cfs/hr baseflow-limited asymptote band — the Event-20 trunk recession continues bending under the same baseflow floor reached by Event 19 around Day 104.
6. ANOMALIES OR SURPRISES None hydrologically. One bookkeeping point worth flagging: NO USGS rating-curve field-revision step has appeared at any gauge through Day 113 — eight days post-record-peak (St. Joe/Harriet were formerly >2× flood stage). Historically, post-major-event field visits produce visible cfs steps; their continued absence is mildly surprising and worth watching at Bear/Richland/Pruitt into Days 114+. Secondary point: the abrupt 7-day-antecedent collapse (Richland 4.7"→0.7" in two days) is purely a moving-window artifact — useful to note because it reclassifies the basin's antecedent state for any new event detection going forward, even though channels remain in recession.