Boxley (07055646) — height: - (a) first: 2.34 ft @ 00:00 - (b) max: 3.34 ft @ 18:15 - (c) last: 3.26 ft @ 23:30 - (d) intraday low: 2.34 ft @ 00:00 (start) - (e) low→peak rise: 2.34 → 3.34 = +1.00 ft over ~18.25 hr; largest 1-hr rise +0.52 ft @ 18:15
Ponca (07055660) — discharge: - (a) first: 177 cfs @ 00:00 - (b) max: 579 cfs @ 21:15 (and 21:30, 21:45, 22:15) - (c) last: 547 cfs @ 23:30 - (d) intraday low: 177 cfs @ 00:00–01:00 - (e) low→peak rise: 177 → 579 = +402 cfs over ~21 hr; intermediate peak 493 @ 15:15 then dip to 421 @ 18:00, then rise to 579 (two pulses)
Pruitt (07055680) — height/discharge: - (a) first: 6.25 ft / 1020 cfs @ 00:00 - (b) max: 6.32 ft @ 22:45 / 1060 cfs @ 22:45 (intraday); the day BEGAN in recession from D-1 8.55 ft peak - (c) last: 6.30 ft / 1050 cfs @ 23:30 - (d) intraday low: 5.27 ft @ 14:45 / 597 cfs @ 14:45 - (e) low→peak rise: 5.27 → 6.32 = +1.05 ft over ~8 hr; 597 → 1060 = +463 cfs. Largest 1-hr rise +0.55 ft @ 16:45
St. Joe (07056000) — height/discharge: - (a) first: 14.54 ft / 13500 cfs @ 00:00 (rising from D-1) - (b) max: 15.05 ft @ 01:45 / 14500 cfs @ 01:30–02:00 — first flood-threshold-exceeding (>8000 cfs) peak of the study, ~1.8× flood threshold - (c) last: 10.29 ft / 6200 cfs @ 22:45 - (d) intraday low: 10.25 ft @ 18:15–18:45 / 6140 cfs @ 18:15 - (e) low→peak rise (post-recession sub-cycle): 10.25 → 10.32 = +0.07 ft over ~2.5 hr; 6140 → 6250 = +110 cfs. Trivial sub-pulse from late-day convective input.
Harriet (07056700) — height/discharge: - (a) first: 8.55 ft / 5320 cfs @ 00:00 - (b) max: 14.24 ft @ 07:30 / 15000 cfs @ 07:30 — also exceeds flood threshold of 9370 cfs (~1.6×) - (c) last: 9.91 ft / 7350 cfs @ 22:45 - (d) intraday low (on recession): 9.90 ft @ 22:00 / 7330 cfs @ 22:00 - (e) low→peak rise: dominated by overnight propagation surge (5320 → 15000 cfs, +9680 cfs over ~7.5 hr). Late-day sub-cycle minimal.
Richland Creek (07055875) — height: - (a) first: 5.13 ft @ 00:00 (recession from D-1 8.89 ft) - (b) max: 5.13 ft @ 00:00 then later sub-peak 4.90 ft @ 16:30/17:00 - (c) last: 4.11 ft @ 23:00 - (d) intraday low: 4.32 ft @ 13:00 - (e) low→peak rise: 4.32 → 4.90 = +0.58 ft over ~4 hr (15:00 onset → 17:00 peak); largest 1-hr rise +0.43 ft @ 15:45
Bear Creek (07056515) — height/discharge: - (a) first: 4.96 ft / 1470 cfs @ 00:00 (recession from D-1 6.30 ft peak) - (b) max: 4.96 ft @ 00:00 (overall); sub-peak 4.78 ft @ 18:00 / 1300 cfs - (c) last: 4.19 ft / 840 cfs @ 23:15 - (d) intraday low: 4.01 ft @ 14:00–14:30 / 669 cfs @ 14:00–14:30 - (e) low→peak rise: 4.01 → 4.78 = +0.77 ft over ~4 hr; 669 → 1300 = +631 cfs. Largest 1-hr rise +0.64 ft @ 16:00
Today was a secondary multi-pulse convective day layered onto a saturated watershed. Basin-max 24-hr QPE was 0.99" in the Richland zone (HUC 0306 = 1.19"). Two pulse clusters:
Spatially scattered, with notable hotspots: Cove Creek 1.19" (Pruitt zone), Headwaters Richland 1.19", Tomahawk Cr 0.71", Clabber Creek 0.98" (ungauged). The Pruitt zone 6-hr max was 1.123" — moderately intense but smaller-scale than D-1.
Antecedent context: extreme. Every HUC12 7-day total is now 2.0–7.1", a complete reversal from D-2 (most <1.0"). Pruitt zone 7-day ~3.8", Richland zone 4.2–4.5", Bear Cr zone 4.0–4.2". This is the wettest antecedent state of the study.
Headline: TWO mainstem flood-threshold exceedances overnight (D-1 → D-2 transition).
Pruitt sub-pulse: Cove Creek HUC 0204 peak 1-hr 0.637" @ 13:02 CDT → Pruitt height peak 6.32 ft @ 22:45 CDT (but discharge peak 1060 cfs @ 22:45; immediate rise peak more relevant: 6.28 ft @ 17:30 / 1040 cfs @ 17:30). Using the 17:30 peak: lag ~4.5 hr peak-to-peak. Pruitt zone 24-hr QPE 0.801". Sub-pulse rise from intraday-low: +1.05 ft / 0.80" = transfer ratio ~1.3 ft/in. Antecedent: 7-day 3.8" (extremely wet). - Comparison: Prior Pruitt wet-antecedent transfer 1.4–1.7 ft/in (Event 8); moist-antecedent 1.6 ft/in (Event 10). Today's 1.3 ft/in is on the low end, within 30% of the prior range — consistent with the gauge being at elevated stage (5.3 ft, not baseflow) where the rating-curve slope is shallower (more cfs per ft, less ft per cfs of inflow). Lag of ~4.5 hr is also consistent with the Event 8 high-flow estimates.
Bear Creek: HUC 0403 peak 1-hr 0.226" @ 12:02 CDT → Bear Cr peak 4.78 ft / 1300 cfs @ 18:00 CDT (from sub-cycle low 4.01 ft / 669 cfs @ 14:30). Lag ~6 hr peak-to-peak. Rise +0.77 ft / 0.42" zone QPE = transfer ratio ~1.83 ft/in. - Comparison: Event 12 Bear Cr transfer was 0.22 ft/in (very dry channel). Today's 1.83 ft/in is >8× higher under extreme wet antecedent. Bear Cr 7-day went from ~1.0" to 4.2". This is the strongest demonstration in the study of antecedent amplification at Bear Creek. Refined Bear Cr transfer: dry ~0.2 ft/in, saturated ~1.8 ft/in (~9× range). High confidence given today's clean signal.
Richland Creek: HUC 0306 peak 1-hr 0.219" @ 15:02 CDT → Richland sub-peak 4.90 ft @ 17:00 CDT. Lag ~2 hr peak-to-peak. Rise +0.58 ft / 0.99" zone QPE (using zone-averaged, though signal mainly from HUC 0306 1.19") = transfer ratio 0.5–0.6 ft/in for the rebound pulse. - Comparison: Event 13 (Day 87) Richland was 0.90 ft/in in-channel. Today's lower value reflects that the gauge was already at 4.3 ft (still saturated channel, but with momentum still falling). Within ~50% — flagged but plausible given the gauge was on active recession when the new pulse arrived. Refined Richland sub-pulse transfer on falling limb: ~0.5–0.6 ft/in, lower than first-rise transfer (~0.9 ft/in). New finding.
Boxley: Zone 24-hr 0.753", 6-hr 0.484". Rise +1.00 ft over the day. Transfer ~1.3 ft/in. - Comparison: Event 11 (dry-antecedent) Boxley showed minimal response — pool-and-drop filled the channel first. Today's antecedent is wet (~3.6"), pools are full, and the rise of +1.0 ft from 0.75" of rain confirms the wet-antecedent Boxley transfer is roughly 1.0–1.5 ft/in vs dry-antecedent <0.3 ft/in. Strong confirmation of local-knowledge pool-and-drop pre-fill behavior (Hailstone observation): once the pools are full from prior events, even modest rainfall produces direct gauge response.
The dominant propagation today was the overnight surge cascade from D-1 evening into D-2 morning: - Pruitt D-1 peak 8.55 ft @ 13:45 CDT - St. Joe peak 15.05 ft @ 01:30 CDT (D-2) → ~11.75 hr from Pruitt peak - Harriet peak 14.24 ft @ 07:30 CDT (D-2) → ~6 hr from St. Joe peak
These are only the mainstem gauges. Note: Pruitt-to-St. Joe lag of ~12 hr is longer than typical 5–7 hr from Event 8, but that's because the St. Joe rise was driven primarily by intra-zone Little Buffalo / Cave Creek rainfall (D-1 had 2.5–2.6" in HUCs 0104, 0305, plus Flatrock 2.64"), with a major component from Richland (D-1 Richland zone 2.63", Richland gauge peak 8.89 ft) — NOT direct Pruitt routing. The St. Joe peak therefore reflects the integration of multiple sub-basin peaks, and its routing lag is to the basin-centroid forcing, not strictly Pruitt.
St. Joe → Harriet ~6 hr is consistent with prior high-flow estimates.
Event 15 (now complete in terms of peak): May 28–29 watershed-wide, moderate-antecedent → flood-scale event. - Total event QPE basin-wide ~2–6" over 36 hr - Two mainstem flood-threshold exceedances (St. Joe 14,500 cfs ~1.8× flood; Harriet 15,000 cfs ~1.6× flood) - Five tributary/headwater peaks: Pruitt 8.55 ft / 2610 cfs, Richland 8.89 ft, Bear Cr 6.30 ft / 3090 cfs, plus St. Joe and Harriet - This is the only flood-scale event of the 90-day study and represents the first complete flood transfer-function calibration data point.
Event 15 transfer ratios (composite): - Pruitt total event rise (3.6 → 8.55 ft) = 4.95 ft on ~3.6" zone QPE = ~1.4 ft/in (matches wet-antecedent range) - St. Joe total event rise (4.1 → 15.05 ft) = ~11 ft on ~2.7" zone QPE for direct, but realistically ~3.5" effective integrating all contributing sub-basins = ~3 ft/in. Comparable to March 2024 reference event (~11 ft rise from ~4–8" rain). St. Joe transfer in flood range = ~2.5–3.5 ft/in, new finding. - Harriet total event rise (4.3 → 14.24 ft) = ~10 ft on ~2.7" zone + upstream propagation = effective ~3 ft/in.