Daily Analysis

Day 14 — 2026-03-14 — No precipitation, continued recession

1. PRECIPITATION SUMMARY

Zero precipitation across all 37 HUC12s for the third consecutive day (3/12-3/14). 7-day antecedent precipitation is essentially unchanged from yesterday (minor rounding differences as the 7-day window shifts), ranging from 1.345" (Water Creek) to 3.217" (Whiteley Creek). The Event 2 rainfall (3/07) will begin rolling out of the 7-day window tomorrow, which should produce a noticeable drop in 7-day antecedent values.

2. GAUGE RESPONSES

All gauges in continued recession with no precipitation input. This is the cleanest recession observation in the study so far — three full dry days.

End-of-day values (3/14 ~23:30 CST):

Gauge EOD 3/13 EOD 3/14 Change 24-hr decline rate
Boxley 2.70 ft 2.60 ft -0.10 ft -0.42%/hr
Ponca 221 cfs 195 cfs -26 cfs -0.49%/hr
Pruitt 374 cfs / 4.71 ft 308 cfs / 4.51 ft -66 cfs / -0.20 ft -0.81%/hr
St. Joe 874 cfs / 5.17 ft 732 cfs / 4.91 ft -142 cfs / -0.26 ft -0.73%/hr
Harriet 1,070 cfs / 4.93 ft 878 cfs / 4.70 ft -192 cfs / -0.23 ft -0.82%/hr
Richland 1.53 ft 1.46 ft -0.07 ft
Bear Creek 16.5 cfs / 2.51 ft 15.0 cfs / 2.48 ft -1.5 cfs / -0.03 ft -0.40%/hr

Key recession finding — UPDATED: The recession rate has slowed significantly compared to Day 12-13. On Day 12-13, all four mainstem gauges with CFS showed ~1.0%/hr exponential recession. Today (Day 14): - Ponca: 0.49%/hr (was ~1.0%/hr) - Pruitt: 0.81%/hr (was ~1.0%/hr) - St. Joe: 0.73%/hr (was ~1.0%/hr) - Harriet: 0.82%/hr (was ~1.0%/hr)

This is expected behavior — as flows approach baseflow, the recession rate slows. The exponential model Q(t) = Q₀ × 0.99^t was a reasonable approximation during the steep portion of the recession but is now overpredicting decline. This directly addresses Open Question #5 from the hypothesis document. The recession is transitioning from the steep "quick flow" component to the slower "baseflow recession" component.

Recession rate comparison — two-phase behavior: - Phase 1 (Day 12-13, ~500-1500 cfs range): ~1.0%/hr at all gauges - Phase 2 (Day 14, ~200-900 cfs range): ~0.5-0.8%/hr, with upper gauges (Ponca) slowing more than lower gauges

This suggests Ponca (195 cfs) is approaching its baseflow, while the lower gauges still have meaningful recession ahead.

3. RAINFALL-RESPONSE PAIRS

None — no precipitation.

4. DOWNSTREAM PROPAGATION

No new event to track. Recession continues uniformly downstream.

5. MULTI-DAY EVENTS

Recreational threshold crossings — confirmed:

Total Optimal window summary for Event 2+3 sequence: - Ponca: Optimal from 3/07 ~07:30 to 3/14 ~16:00 = ~7.4 days (now Low-but-Floatable) - Pruitt: Optimal from 3/07 ~03:00 through at least 3/17 = 10+ days projected - St. Joe: Optimal since 3/07, likely continuing through 3/20+ = 13+ days projected - Harriet: Similar to St. Joe

6. ANOMALIES OR SURPRISES

Ponca recession flattening: Ponca's recession rate dropped to 0.49%/hr — roughly half the rate of the other gauges. This is notable. At 195 cfs, Ponca may be approaching a baseflow floor that is higher than might be expected for this time of year. The extremely slow decline (only 26 cfs in 24 hours at a flow of ~200 cfs) suggests significant sustained baseflow from springs/karst in the Ponca zone. This will be an important observation for baseflow characterization (Open Question #6).

Local knowledge cross-reference: The Pruitt gauge channel scouring note from local knowledge remains relevant. At these lower flows (308 cfs, 4.51 ft), the reported river-right bias in flow could mean the Pruitt gauge is underreading actual flow. However, the height-discharge relationship appears consistent today, and we're not relying on cross-gauge CFS comparisons, so this is a background note rather than an active concern.