Daily Analysis

Day 53 (April 22, 2026) — Continued dry recession, Day 4 with no precipitation

1. PRECIPITATION SUMMARY

Zero precipitation across all 37 HUC12s for the fourth consecutive day (since Apr 18 Pulse 2). The 7-day antecedent values remain unchanged from Apr 20-21 (ranging 0.77-1.45"), but these will begin rolling off tomorrow as the Apr 15-16 Pulse 1 exits the 7-day window. The watershed is drying.

2. GAUGE RESPONSES

All gauges continued declining. No significant rises flagged.

End-of-day values and daily change (Apr 21 EOD → Apr 22 EOD):

Gauge	Apr 21 EOD	Apr 22 EOD	Daily Change	Status
Boxley	2.30 ft	2.24 ft	-0.06 ft/day	Approaching study-period low
Ponca	127 cfs	120 cfs	-7 cfs/day	Below Low-but-Floatable (<150), in Too Low zone
Pruitt	3.89 ft / 148 cfs	3.83 ft / 133 cfs	-0.06 ft / -15 cfs/day	Now in Low-but-Floatable (100-200); approaching Too Low
St. Joe	4.05 ft / 364 cfs	3.93 ft / 321 cfs	-0.12 ft / -43 cfs/day	Still in Optimal (>200)
Harriet	4.13 ft / 479 cfs	4.03 ft / 419 cfs	-0.10 ft / -60 cfs/day	Still in Optimal (>200)
Richland	1.42 ft	1.36 ft	-0.06 ft/day	Low baseflow
Bear Creek	2.21 ft / 19.8 cfs	2.20 ft / 19.2 cfs	-0.01 ft / -0.6 cfs/day	At/near baseflow

Key recession observations: - Upper gauges (Boxley, Ponca, Pruitt) have recession rates that are slowing markedly — they're approaching true baseflow. Ponca dropped only 7 cfs today vs. 9 cfs yesterday. Pruitt dropped 15 cfs vs. 21 cfs yesterday. - St. Joe recession rate decreased from -65 cfs/day (Apr 21) to -43 cfs/day (Apr 22). This is consistent with the exponential decay pattern expected as the Event 4+6 pulse works through. - Harriet recession rate decreased from -89 cfs/day (Apr 21) to -60 cfs/day (Apr 22). Similarly decelerating. - The downstream gauges (St. Joe, Harriet) are receding faster than the upper gauges in absolute terms but are still well above their Optimal thresholds.

3. RAINFALL-RESPONSE PAIRS

No new rainfall-response pairs. Recession tracking only.

4. DOWNSTREAM PROPAGATION

No propagation signals. Clean baseflow recession at all gauges.

5. MULTI-DAY EVENTS

Finalizing Event 4+6 combined recession and Optimal duration projections:

• Ponca: Exited Low-but-Floatable (>150 cfs) on Apr 19 and has been in Too Low since. Ponca total floatable duration (>150 cfs) from Event 4: ~15.4 days (confirmed, no change).
• Pruitt: Dropped below 200 cfs (Optimal threshold) definitively around Apr 20 ~02:30 CST. Now at 133 cfs, firmly in Low-but-Floatable. Confirmed Optimal duration ~16.0 days from Event 4 start.
• St. Joe: At 321 cfs EOD, declining ~43 cfs/day (decelerating). At this rate, St. Joe will exit Optimal (~200 cfs) in approximately 2.8 days, around Apr 25. Previous estimate was Apr 23-24. Revising upward — the deceleration in recession rate means St. Joe will sustain Optimal longer than projected yesterday. New projection: St. Joe exits Optimal ~Apr 24-25 (splitting the difference as recession continues to slow). Total Optimal duration from Event 4: ~20-21 days.
• Harriet: At 419 cfs EOD, declining ~60 cfs/day (decelerating). At this rate, Harriet will exit Optimal (~200 cfs) in approximately 3.7 days, around Apr 26. Previous estimate was Apr 24-25. Revising upward — same deceleration logic. New projection: Harriet exits Optimal ~Apr 25-26. Total Optimal duration from Event 4: ~21-22 days.

6. ANOMALIES OR SURPRISES

• The recession deceleration at St. Joe and Harriet is more pronounced than expected. On Apr 21, both appeared to be in accelerated recession after the Event 6 propagation wave passed. Today they're clearly decelerating, suggesting we've transitioned from event-driven recession to groundwater-sustained baseflow recession. This is the classic two-phase recession behavior in karst watersheds — a fast interflow component drains first (1-3 days post-event), followed by a much slower baseflow component.
• Pruitt's recession has nearly flattened at ~133 cfs, suggesting it's close to its baseflow equilibrium for current conditions. At 133 cfs, Pruitt is slightly above the pre-Event 4 baseflow of ~48 cfs, indicating significant groundwater recharge from the April storms is still sustaining elevated flows.
• Bear Creek has dropped to 2.19-2.20 ft / 18.6-19.2 cfs, which is below the post-rating-curve-update baseflow of ~21 cfs at 2.23 ft. This may represent true seasonal baseflow decline or could indicate the rating curve is slightly off at these very low stages. Worth monitoring.