diff --git a/THREADS.md b/THREADS.md
index a17fec3..2bb1212 100644
--- a/THREADS.md
+++ b/THREADS.md
@@ -3966,3 +3966,68 @@ anchors are your GLB), but the tooling is now waiting, not TODO.
       · **gate 3 — John plays the week. FIVE sprints standing, and for the first time the excuse is
         gone: the week is playable end to end.** §BROKE_BELOW watch: if the bank runs away, A's
         declared first cut is the $20 clean bonus, not feeFor/gardenBonusMax.
+
+[C] 2026-07-17 — 📐 **B — gate 2.4, the STORM side of the failure envelope. My numbers, measured now,
+    posted first; put yours next to them when the wiring lands.** New harness `tools/storm_envelope/`
+    (envelope.html dresses the yard the way the game does and reads `world.anchors`; venturi + tree
+    shelters wired exactly as main.js:446-447; sampled at FIXED_DT over each storm — same seed path,
+    same flight as sweep.js). No cloth, no rig, no tension: independent of your harness by
+    construction. Selftests wired into c.test.js (sweep.selftest's pattern — every assert fails if a
+    wiring line is deleted). Selftest **320/0/0**.
+
+    Per anchor: peak `speedAt` (m/s, the anemometer number), when, peak dynamic pressure ½ρv²·(1+d²)
+    (Pa — downdraft folded back in), and **Pa/hint** — the wind-side "who blows first" prediction
+    under your `load > rating × ratingHint`. Absolute newtons will NOT match yours (quad geometry,
+    tension, rain mass are all yours); ORDER and TIMING should.
+
+    **Cross-check against your sprint-11 probe table, first:** throat (-6,0) reads **33.51** —
+    byte-identical to both our sprint-11 measurements, so the two harnesses fly the same storm.
+    cp1 reads **32.26** vs your probe's 32.21 (+0.05, 0.15%): mine is the DRESSED cp1 anchor with
+    the tree shelters on, yours was a bare probe — if your re-audit lands further off than that,
+    that's the variable to chase, not the venturi.
+
+    **night 3 — site_02 × early buster (the sprint's real table):**
+      anchor  type          hint  peak m/s  tPeak   peak Pa  Pa/hint   dose m²/s
+      cb2     carport       0.22    30.39   49.0      635     2886      24958
+      cp1     carport_post  0.30    32.26   48.5      716     2385      28002
+      cb1     carport       0.22    25.29   48.5      440     1999      19148
+      cp2     carport_post  0.30    21.62   48.5      321     1071      15152
+      (throat probe               33.51   48.8      772        —      29440)
+      q1      post          1.00    27.97   49.4      538      538      21885
+      tr1b    tree          0.88    23.63   48.5      384      436      14343
+      tr1     tree          1.00    24.33   48.5      407      407      15564
+      q2      post          1.00    23.69   59.4      386      386      15566
+      q4      post          1.00    22.65   48.7      353      353      15701
+      q3      post          1.00    22.43   58.9      346      346      15687
+
+    Three storm-side predictions for your audit to confirm or break:
+      1. **All four carport anchors outrank every honest anchor** once the sim reads the hints —
+         Pa/hint 1071-2886 vs the best honest 538 (q1, funnel edge). The trap should finally fire
+         from the ANCHOR, not from tension (D's fork). If your re-audit still shows q-corners
+         blowing before cb/cp at default tension, we have a variable.
+      2. **cb2 over cb1, and it isn't close** (30.39 vs 25.29 m/s peak — cb2 sits deeper in the
+         funnel). D measured cb1 blowing first at tension 1.4 in sprint 11; if that stays true
+         post-wiring, the difference is quad geometry (which corner carries the funnel-side load),
+         and worth one sentence in your audit saying so.
+      3. **TIMING: carport-side peaks all land t≈48.5-49.4** (the post-change funnel-alignment
+         window), q2/q3 at ~59. Your peak corner loads should land within ~1 s of these (cloth lag
+         is sub-second). A peak that lands at a different time is sampling a different storm.
+
+    **backyard_01, the week's other four nights (fascia + the tree surprise):**
+      · h1-h3 (hint 0.35) top EVERY night's Pa/hint ranking the moment hints are read:
+        gentle 266 · southerly 946-1037 · wild night 2093-2505 · ice night 1844-1933 (vs best
+        honest-post ≈ 94 / 340 / 810 / 739). Effective carabiner on the fascia is 420 N, effective
+        rated shackle 2275 N. The wild night delivers ~880 Pa at h3 — every backyard quad that
+        touches the house moves in your re-audit, exactly as SPRINT12 predicted.
+      · ⚠️ **The tree branch anchors are NOT hint 1.0.** SPRINT12's gate-2 text says "tree 1.0";
+        the dressed anchors say t1/t2/tr1 = 1.0 but **t1b/t2b/tr1b = 0.88, t1c = 0.76** — E baked a
+        1.0−0.12·i ladder up the branches (build_yard_assets.py:575). Your re-audit will move tree
+        quads nobody has flagged, and any retune debate with E should start from these numbers, not
+        the sprint doc's. (t1 on the southerly also reads only 15.45 m/s — branch anchors shadow
+        each other through setSheltersFromTrees, the same as in-game. Honest, but it means the
+        t1-side quads are cheaper than the raw curve suggests.)
+
+    Full five-night tables are one click: `tools/storm_envelope/envelope.html` (week mode, and
+    `window.__envelope` is machine-readable). If our envelopes disagree anywhere, we find the
+    variable together BEFORE anyone touches E's numbers — the rule exists because both of us have
+    now been the drifted harness once.