PRE-ANALYSIS (per-gauge facts, all timestamps CDT):
Light, distributed evening convective rain on a wet, actively-receding basin. Basin-max 24-hr QPE 0.490" (Boxley zone, HUC 0201 Terrapin Branch, peak-1hr 0.391" @20:02). Secondary centers: St. Joe own-zone 0.385" (Flatrock 0206 0.551" / 0.282"/hr — highest HUC total; Headwaters Big Cr 0302 0.524"; Cane Branch 0309 0.447"; Shop/Headwaters LB ~0.44"), Ponca 0.355", Richland 0.356" (Headwaters Richland 0.415"), Pruitt 0.307", Harriet 0.195", Bear 0.134" (spatial minimum), ungauged 0.117". All zone averages ≤0.49" and intensities ≤0.39"/hr — a Tier-1 (sub-event) pulse, not a coherent storm.
Only the two uppermost gauges showed an attributable response; everything from Pruitt down remained in pure Event-21 flood-limb recession.
Boxley — today's only solid pair. - Lag: QPE peak 20:02 → gauge peak 21:00 = ~1.0 hr. - Apparent transfer: +0.27 ft / 0.49" = 0.55 ft/in. Recession-corrected: without rain Boxley would have continued draining (~0.04 ft/hr × ~6 hr ≈ −0.24 ft to ~3.05 ft); gross rise to 3.49 ≈ 0.44 ft → ~0.9 ft/in recession-corrected. - Antecedent: very wet, Boxley 7-day = 3.65" (Event-21 saturation), and the pool was already filled/draining (3.2 ft, well above seepage baseline). - Cross-event comparison: prior wet/moist Boxley 0.71–0.84 (Events 2, 3); very-wet/primed 1.30–1.42 (Events 4, 20); very-wet+extreme-intensity 2.28 (Event 19). Today's apparent 0.55 is ~25–35% below the wet band (flag), but the recession-corrected ~0.9 ft/in sits squarely in the wet/moist band. The ~1 hr lag is even shorter than the documented "≥1.0" wet/primed regime — fully consistent with a saturated, already-filled pool. Refinement: on an actively-draining Boxley limb, the apparent ft/in understates response by the concurrent recession slope; report both. Antecedent matches the "wet/primed" precedent (wet/wet).
Ponca — incomplete pair. +93 cfs / 0.355" ≈ 262 cfs/in (lower-bound, peak uncaptured + on a receding limb + partial Boxley contribution). Not comparable to the clean wet 1,000–1,220 cfs/in (Events 2, 20) because the response is superimposed on recession and unfinished. No refinement; flag as lower-bound only.
Non-detections (reinforce Q10 / detection floor): St. Joe own-zone 0.385" (incl. 0.55" cell), Pruitt 0.307", Richland 0.356", Bear 0.134", Harriet 0.195" — all absorbed with zero attributable rise on the wet, receding limb. Forcing magnitude (not antecedent wetness) again gates detection at the large integrators; the receding-basin absorbed-pulse floor at the trunk is > ~0.4" zone-average for a single sub-cell when the gauge is mid-recession.
No clean cascade today — the pulse only registered at Boxley and (partially) Ponca, and Ponca's peak was uncaptured. Boxley peak 21:00 → Ponca still rising at 23:15 is consistent with the documented Boxley→Ponca 1.75–5 hr window but cannot be closed. The St. Joe→Harriet segment today is recession-only (no propagating pulse). (Note: Event-21's St. Joe→Harriet flood propagation of ~6.5 hr — see §5 — is the meaningful propagation datapoint this cycle.)
Today is recession-limb Day 1 of Event 21 (the major upper-basin flood of Jun 22–23, Days 114–115, which post-dates the last hypothesis update). From the context summaries: Boxley hit a study-record 9.06 ft, Ponca 8,700 cfs, Pruitt study-record 14.27 ft / 9,710 cfs (all far above flood), while the trunk attenuated to St. Joe 7,890 cfs @~02:45 Jun 23 (99% of the 8,000 flood — did NOT cross) and Harriet 6,870 cfs @~09:15 (73% of flood). St. Joe→Harriet peak-to-peak ~6.5 hr at high flow — a third confirmation of the 6–6.5 hr flood-flow timing (Events 15, 20, 21).
Today's recession rates (Event-21 limb): - St. Joe ~34 cfs/hr @ ~2,050 cfs (2430→1660 / 22.5 hr; stage ~0.043 ft/hr). vs Event-20 Day-109 ~28 @2,000 — ~20% faster (fresher/larger limb), same band. - Harriet ~48 cfs/hr @ ~2,600 cfs (3160→2030 / 23.75 hr; stage ~0.042 ft/hr). vs Event-20 Day-109 ~33 @2,600 — ~45% faster; Harriet limb peaked only ~30 hr ago (steeper portion). Persistent Harriet-higher-on-limb offset holds. - Pruitt ~10 cfs/hr (784→555).
All five mainstem gauges are back in Optimal today (Boxley by section thresholds; Ponca ~400–550; Pruitt 555–784; St. Joe 1,660–2,430; Harriet 2,030–3,160) — Event 21 reset Pruitt and Ponca back up after their Day-109/112 Optimal exits.