Pre-analysis per-gauge facts (today, 2026-05-16): - Boxley (height): first 2.03 ft @ 00:00 | max 2.03 ft @ 00:00/00:15/00:45 | last 1.96 ft @ 23:30. Pure recession, new study low. - Ponca (cfs): first 87.7 @ 00:00 | max 87.7 @ 00:00–01:15 | last 82.8 @ 23:30. Min 81.3 @ 18:00. Pure recession. - Pruitt (height): first 3.64 @ 00:00 | max 3.65 @ 02:45 | last 3.57 @ 23:30. Min 3.55 @ 17:30. Discharge: first 92.2 | max 94.2 @ 02:45 | min 75.8 @ 17:30 | last 79.3 @ 23:30. - St. Joe (height): first 3.73 @ 00:00 | max 3.75 @ 00:45 & 02:30 | last 3.63 @ 22:45. Min 3.62 @ 21:30 / 22:15. Discharge: first 272 | max 279 @ 00:45 & 02:30 | min 239 @ 21:30/22:15 | last 242 @ 22:45. - Harriet (height): first 3.90 @ 00:00 | max 3.92 @ 00:45 | last 3.82 @ 22:45. Discharge: first 347 | max 358 @ 00:45 | min 305 @ 20:30 onward | last 305 @ 22:45. - Richland (height): first 1.41 | max 1.41 @ 00:00 | last 1.32 @ 23:00. Pure recession. - Bear Cr (height): first 2.13 | max 2.13 @ 00:00 etc. | last 2.10 @ 23:15. Discharge: first 15.5 | max 15.5 | min 13.7 @ 21:15 | last 14.1.
All seven gauges advanced study-period lows again — third consecutive day of simultaneous new lows.
Today brought the first meaningful precipitation since Event 10's tail (Day 74). A south-to-southeast band moved across the lower watershed during the late-morning–afternoon window (~11:00–15:00 CDT peak hours), concentrated in the Bear Creek, Harriet, ungauged, and southeastern St. Joe zones.
Zone-averaged 24-hr QPE (today): - Harriet: 0.126" (peak 1-hr 0.051", 6-hr 0.124") — basin max - Ungauged: 0.130" (Hickory Cr 0.158", Davis Cr 0.154", Long Cr 0.153") - Bear Creek: 0.108" (Hdwtrs 0.106", Outlet 0.111") - Richland: 0.107" (Falling Water 0307 0.114", Hdwtrs Richland 0.100") - St. Joe (zone-avg): 0.060", but very heterogeneous — Cave Cr 0.117", Outlet Richland 0.113", Calf Cr 0.113", Rocky Hollow 0.131", Lick Cr 0.055", Little Buffalo headwaters tier ~0.02" - Pruitt: 0.006" (effectively zero) - Ponca: 0.004" - Boxley: 0.002"
Spatial pattern: Strong southeast-to-east gradient. The upper-Buffalo (Boxley/Ponca/Pruitt) received essentially nothing. Cells concentrated over the lower-watershed Ozark karst belt and the ungauged southeastern HUC12s. Peak 1-hr cores ~0.04–0.09", well below the ~0.3" detection threshold for gauge response established empirically.
No gauges rose meaningfully. All seven advanced study-period lows simultaneously, continuing the post-Event-10 recession trajectory.
Bear Creek noteworthy: zone received 0.108" today (largest single-day input since Event 10) and still showed no rise. This further calibrates the detection floor — Bear Cr requires more than 0.1" zone-avg to register, even with moist antecedent.
No detectable rainfall→response pairs today. Rainfall was sub-threshold at every gauge. This is itself a calibration finding:
No comparison to prior-event lag/transfer ratios possible — no event today.
No propagation today; all recession.
Continued post-Event-10 recession, now Day 5 post-final-peak (St. Joe final peak D73 13:15; Harriet final D74 01:45).
St. Joe Day 76 → Day 77 recession: 279 → 242 cfs across 22.75 hr = −1.63 cfs/hr. D75→D76 was −1.85 cfs/hr. Day-on-day decay ratio = 1.63/1.85 = 0.88 — slowing the rate of slowing, as expected deep in the geometric-decay regime. Sequence to date (D74→D75→D76→D77 cfs/hr): 3.1 → 1.85 → 1.63. Compare Event 9 (6.96 → 5.1 → 3.2): Event 10 recession is decelerating faster early but flattening into a similar low-flow tail.
Harriet Day 76 → Day 77 recession: 358 → 305 cfs across 22.75 hr = −2.33 cfs/hr. D75→D76 was −2.36 cfs/hr (ratio 0.99 — virtually identical). Harriet has reached a near-steady recession slope (~2.3 cfs/hr).
Pruitt: 96.2 → 79.3 cfs across 23.5 hr = −0.72 cfs/hr. Small absolute change reflects how close to baseflow the gauge already is.
Boxley: −0.07 ft / 24 hr. Continues slow seepage decline.
Spatial inversion in QPE: Today is the first day in the study where the lower watershed (Harriet/Bear Cr/ungauged southeastern) received the most rain while the upper watershed (Boxley/Ponca/Pruitt) received essentially none. Every prior event had its highest QPE in the upper or central Richland zones. This was a different storm regime — southeasterly-tracking convection. Notable for the study's spatial-pattern catalog.
Sub-threshold confirmation at moist Richland antecedent: Richland 7-day antecedent is 1.47" zone-avg (highest in basin today) and 0.107" today still produced zero rise. This narrows the Richland detection threshold: even with a moist column from Event 10, ~0.1" is insufficient. Likely floor ~0.20" zone-avg or with concentrated 1-hr core.
Bear Creek non-response at 0.108" zone QPE: This is the largest Bear Cr input since Event 10's 0.33" (also sub-threshold). Bear Cr has now demonstrated non-detection at 0.33", 0.18" (D68-era), and 0.108". Bear Cr detection floor is firmly >0.13" zone-avg, probably ≥0.25".
Third consecutive day of simultaneous new study lows across all 7 gauges. The watershed is dewatering steadily. Forecast watch: any meaningful event in the remaining 13 days will hit very dry antecedent — useful calibration territory.