Daily Analysis

Pre-Analysis Per-Gauge Facts

• Boxley (07055646): (a) first 2.05 ft @ 00:00; (b) max 2.05 ft @ 00:00; (c) last 1.97 ft @ 23:30; (d) intraday low 1.97 ft @ 22:30; (e) low→peak: 1.97 → 1.98 ft @ 22:45 = +0.01 ft over 15 min (noise-level).
• Ponca (07055660): (a) first 101 cfs @ 00:00; (b) max 101 cfs @ 00:00 (sustained through 04:00); (c) last 92.6 cfs @ 23:30; (d) low 92.6 cfs first reached @ 18:30; (e) low→peak: 92.6 → 94.3 cfs @ 18:45 = +1.7 cfs over 15 min (single-bin noise; no real pulse).
• Pruitt (07055680): height (a) 4.04 @ 00:00; (b) max 4.04 @ 00:00; (c) last 3.93 @ 23:30; (d) low 3.91 @ 17:30, also 22:30; (e) low→peak: 3.91 → 3.94 ft @ 18:00 = +0.03 ft over 30 min (also a second cycle: 3.91 @ 22:30 → 3.93 @ 23:30 = +0.02 ft, ongoing). Discharge: max 188 cfs @ 00:00, min 153 cfs @ 17:30, last 158 cfs @ 23:30.
• St. Joe (07056000): (a) 5.32 ft / 1010 cfs @ 00:00; (b) max 5.32 ft @ 00:00; (c) last 4.93 ft / 785 cfs @ 22:45; (d) low 4.93 ft @ 22:45 (still falling); (e) low→peak: pure recession; only sub-cycle bump 4.99 → 5.02 ft @ 17:30 (+0.03 ft) noted before resuming fall.
• Harriet (07056700): (a) 5.35 ft / 1450 cfs @ 00:00; (b) max 5.35 ft @ 00:00; (c) last 4.99 ft / 1120 cfs @ 23:45; (d) low 4.99 ft @ 23:15; (e) pure recession; only micro-bump 5.00 → 5.02 ft @ 22:15 (+0.02 ft, noise).
• Richland Creek (07055875): (a) 1.74 @ 00:00; (b) max 1.74 @ 00:00; (c) last 1.58 @ 23:00; (d) low 1.58 @ 23:00; (e) pure recession; only sub-cycle 1.59 → 1.60 ft @ 21:45 (+0.01 ft noise).
• Bear Creek (07056515): height (a) 2.81 @ 00:00; (b) max 2.81 @ 00:00; (c) last 2.62 @ 23:15; (d) low 2.62 @ ~22:00; (e) gradual recession only on height. Discharge shows a striking jump: min 60.0 cfs @ 17:45–18:15, then 60.0 → 71.7 cfs @ 18:30 (+11.7 cfs, +20% step in 15 min) with no corresponding height change — clearly a rating-curve revision / discrete cfs-table change applied mid-day, not a real flow rise.

1. Precipitation Summary

After two zero days, light convective rainfall returned, concentrated in the upper basin: - Boxley zone (0.302" zone-avg, 0.246" peak 1-hr @ 22:02 CDT) — highest QPE today, concentrated late evening over HUC 110100050201 (Terrapin Branch-Buffalo). - Ponca zone (0.151"): Beech Cr 0.219" / 0.133" peak 1-hr. - Pruitt zone (0.167"): Cove Cr 0.174" (peak 1-hr 0.153" @ 23:02), Hoskin 0.161" (peak 1-hr 0.131" @ 23:02). - St. Joe zone trace (0.069" avg, with Headwaters Little Buffalo 0.199" the standout). - Bear Creek essentially zero (0.001"); Harriet 0.008"; Richland 0.024" (Headwaters 0.041").

Geographic gradient is clear: upper basin wet, lower basin dry. All forcing landed in the final ~3 hours (22:00 D-94 onward), so most of the runoff response will land overnight/tomorrow. Antecedent zone-7day for upper-basin targets: Boxley 1.85", Cove Cr 4.81", Hoskin 4.26" — Pruitt zone still moderately wet; Boxley zone drying out (down from 2.83" yesterday).

2. Gauge Responses

Today is dominated by recession with one developing late-evening response: - Boxley: −0.08 ft net (2.05 → 1.97 ft). Steady decline, no rise yet despite 0.302" zone QPE landing in last 90 minutes. Per pool-and-drop hypothesis, expect minimal-to-no Boxley response on this magnitude / moderate antecedent — consistent with Event 11 observation that dry-leaning headwater rain "fills pools" first. - Ponca: 101 → 92.6 cfs (−8% across day). Smooth recession. - Pruitt: Net fall 4.04 → 3.93 ft (−0.11 ft) and 188 → 158 cfs (−16%). But late-evening uptick is visible: bottomed 3.91 ft @ 22:30, rose to 3.93 ft by 23:30 (+0.02 ft, ongoing). This is the leading edge of response to the Cove Cr / Hoskin pulse that peaked at 23:02 CDT. Peak forcing was only ~25 minutes before EOD, so the gauge has barely begun responding. - St. Joe: 5.32 → 4.93 ft / 1010 → 785 cfs (−0.39 ft / −22% cfs in 23 hr). Recession-only; the brief 17:30 bump (+0.03 ft) is too small to attribute to today's QPE. - Harriet: 5.35 → 4.99 ft / 1450 → 1120 cfs (−0.36 ft / −23%). Pure mainstem recession. - Richland: 1.74 → 1.58 ft (−0.16 ft). Steady recession. - Bear Creek: Height 2.81 → 2.62 ft (−0.19 ft, smooth). Discharge 60.0 → 71.7 cfs step at 18:30 with no height change = rating-curve adjustment / data artifact, NOT a real flow event. Bear Cr zone QPE today: 0.001". Important to flag this as the kind of mid-day cfs jump that should NOT be interpreted as runoff.

3. Rainfall-Response Pairs

Pruitt (late-evening developing response, partial): - Forcing: Pruitt zone 0.167", peak 1-hr 0.153" @ 23:02 CDT (Cove Cr) + 0.131" (Hoskin) simultaneously. - Response so far: low 3.91 ft @ 22:30 → 3.93 ft @ 23:30 (+0.02 ft over 1 hr). - Lag: forcing peak 23:02 → current rise still ongoing at 23:30 — peak not yet reached. Provisional lag estimate: peak likely 02:00–05:00 D-96 → 3–6 hr lag. Cannot complete pair today. - Antecedent: zone-equivalent (Cove 4.81", Hoskin 4.26") = moderately wet, similar to Event 17 (Cove 4.37", Hoskin 4.84"). - Cross-event comparison: Event 17 (Day 93) saw Cove Cr 1.022" + Hoskin 0.78" produce no measurable Pruitt peak on similar antecedent. Today's forcing (0.17" zone, 0.15" peak 1-hr) is even smaller — consistent with the Event-17-derived hypothesis that ≥1.5" zone-average is needed to drive a propagating Pruitt response over baseflow. The +0.02 ft uptick observed is right at the noise floor and may be the same "leading-edge twitch" pattern, not a true propagating pulse. Provisionally: today's forcing should NOT produce a meaningful Pruitt peak, consistent with the sub-threshold hypothesis.

Boxley (no response yet): - Forcing: 0.302" zone, peak 1-hr 0.246" @ 22:02 CDT in Terrapin Branch (drains directly to gauge). - Response: zero rise through 23:30 (still falling). - Antecedent: Boxley zone 7-day 1.85" — driest the zone has been in the recent stretch (was 2.83" yesterday, 3.92" March-late). Per pool-and-drop hypothesis, the first ~0.3" on drying conditions may produce no gauge response as it refills hydraulic-discontinuity pools. This is a candidate confirmation of local knowledge — watch Day 96 for delayed Boxley signal.

Bear Creek (cfs artifact): - The 60 → 71.7 cfs step at 18:30 has no height change and zero QPE in the Bear Cr zone. This is almost certainly a USGS rating-curve revision applied to the gauge today — possibly the post-Event-15/16/17 field-visit update finally posted. Not a rainfall response. Per local knowledge guidance, treat as a rating-curve event and disregard for transfer-function inference.

4. Downstream Propagation

No new propagating pulse today. The day-long mainstem signal is pure recession from prior events, draining Days 91–92 (Event 16 + secondary) baseflow tail. St. Joe and Harriet continue the converged-rate behavior noted Day 95 (−0.39 vs −0.36 ft per 23 hr ≈ identical absolute rates), confirming the propagation pipeline remains empty.

The Pruitt uptick at 22:30–23:30 will, IF it propagates, be expected at St. Joe ~03:00–05:00 D-96 (per 5–9 hr Pruitt→St. Joe routing window) and Harriet ~08:00–11:00 D-96. But given sub-threshold forcing, propagation is unlikely.

5. Multi-Day Events

The day is the front-end of a potential new event (the first QPE in ~48 hr). Whether it qualifies as a tier-1 event depends on Day 96 forcing continuation. As of D-95 end, this is a small late-evening convective pulse, not yet event-scale.

6. Anomalies / Surprises

• Bear Cr cfs step (60.0 → 71.7 cfs @ 18:30 with no height change, no QPE): textbook rating-curve revision artifact. Reinforces local-knowledge guidance to trust height over cfs. New finding worth documenting: post-flood-event field visits produce visible cfs step changes — this is the first one cleanly captured mid-study. Helps validate the Event-15 calibration prediction (rating curves should now be in best condition of study).
• Boxley zone hit by largest QPE (0.302") yet showed zero response — consistent with pool-and-drop hypothesis on drying antecedent (1.85"). Sets up an excellent natural experiment: if Day 96 brings continued moderate rain, we may see a "delayed-onset" Boxley response that confirms the pool-fill threshold. If Day 96 is dry, we will have evidence that ~0.3" on 1.85" antecedent does NOT exceed pool-fill threshold.
• St. Joe afternoon sub-cycle bump (5.04 → 5.02 → 5.07 → 5.02 ft around 14:30–17:30) is curious — no upstream forcing supports it. Likely measurement noise at low-flow on the wide rating curve; no causal attribution.