Daily Analysis

Day 52 (April 21, 2026) — Continued Recession, No Precipitation

1. PRECIPITATION SUMMARY

Zero precipitation across all 37 HUC12s. This is the third consecutive dry day (Apr 19-21). Seven-day antecedent precip is unchanged from yesterday at 0.77-1.45" across the watershed, but these values will begin declining as the Apr 15-18 Event 6 rainfall rolls out of the 7-day window.

2. GAUGE RESPONSES

All gauges continued steady recession with no new inputs. No significant rises at any gauge.

End-of-day status (Apr 21 EOD vs Apr 20 EOD):

Gauge Apr 20 EOD Apr 21 EOD Change Status
Boxley 2.37 ft 2.30 ft -0.07 ft Declining steadily
Ponca 136 cfs 127 cfs -9 cfs Below Too Low (<150), declining
Pruitt 3.97 ft / 169 cfs 3.89 ft / 148 cfs -0.08 ft / -21 cfs Now below Low-but-Floatable (<200); approaching Too Low (<100) boundary still distant
St. Joe 4.22 ft / 429 cfs 4.05 ft / 364 cfs -0.17 ft / -65 cfs Still in Optimal (>200), declining
Harriet 4.27 ft / 568 cfs 4.13 ft / 479 cfs -0.15 ft / -89 cfs Still in Optimal (>200), declining
Richland 1.49 ft 1.42 ft -0.07 ft Low baseflow recession
Bear Creek 2.23 ft / 21.0 cfs 2.21 ft / 19.8 cfs -0.02 ft / -1.2 cfs Near baseflow

Recession rates today: - Boxley: ~0.07 ft/day (consistent with yesterday's 0.08 ft/day — slowing slightly) - Ponca: ~9 cfs/day (slowing from 11 cfs/day yesterday) - Pruitt: ~21 cfs/day (accelerated slightly from ~34 cfs yesterday — wait, that's actually slower; yesterday was 169→169? Let me recalculate. Apr 19 EOD: 203 cfs, Apr 20 EOD: 169 cfs = -34/day. Apr 20 EOD: 169 cfs, Apr 21 EOD: 148 cfs = -21/day. So recession is slowing.) - St. Joe: ~65 cfs/day (yesterday was ~66 cfs/day — nearly identical) - Harriet: ~89 cfs/day (yesterday was ~100 cfs/day over 24 hrs based on ~568 EOD Apr 20 vs ~529 at start of Apr 19... Actually Harriet held relatively steady yesterday due to propagation. Today's faster decline reflects the final wave passing.)

3. RAINFALL-RESPONSE PAIRS

No new pairs today. Dry day.

4. DOWNSTREAM PROPAGATION

The downstream propagation pattern from Event 6 Pulse 2 is now fully resolved. The wave has passed through all gauges. Notably: - St. Joe peaked from Pulse 2 on Apr 20 ~07:00 (495 cfs) and is now in clean recession at 364 cfs. - Harriet peaked from Pulse 2 on Apr 20 ~13:00-18:30 (594 cfs) and is now clearly declining at 479 cfs.

The Pulse 2 wave propagation is confirmed: Pruitt peak ~Apr 19 08:00 → St. Joe peak ~Apr 20 07:00 (~23 hr) → Harriet peak ~Apr 20 13:00-18:30 (~6-11 hr after St. Joe). This is consistent with Event 4 propagation timing at similar flow levels.

5. MULTI-DAY EVENTS

Event 4+6 Combined Recreational Duration — Final Accounting:

Key threshold crossings now finalized: - Ponca floatable (>150 cfs): Exited ~Apr 19 21:00. Total duration from Apr 4 ~11:00 = ~15.4 days. ✓ Already recorded. - Pruitt Optimal (>200 cfs): Exited ~Apr 20 02:30 based on yesterday's data. Total from Apr 4 ~09:00 = ~16.7 days. ✓ Already recorded. - Pruitt Low-but-Floatable (>100 cfs): Still above 100. Current 148 cfs declining ~21 cfs/day → should remain above 100 for ~2-3 more days absent rain. - St. Joe Optimal (>200 cfs): Current 364 cfs, declining ~65 cfs/day. At this rate, will exit Optimal (~200 cfs) around Apr 23-24 (~19.5-20.5 days total from Apr 4). Revising previous estimate of Apr 25-27 downward slightly — recession rate is a bit faster than projected. - Harriet Optimal (>200 cfs): Current 479 cfs, declining ~89 cfs/day. At this rate, will exit Optimal (~200 cfs) around Apr 24-25 (~20-21 days total from Apr 4). Revising previous estimate of Apr 27-30 downward — recession is steeper than expected at Harriet.

Revised projections note: The faster-than-expected recession at both St. Joe and Harriet suggests that the subsurface/baseflow contribution from the April events is tapering. The 7-day antecedent will drop below 1.0" for most HUC12s within the next 2-3 days as Event 6 rolls out, which should further accelerate recession.

6. ANOMALIES OR SURPRISES