fix: align gaussian probability with local forecast date

src/analysis/trend_engine.py

@@ -312,6 +312,26 @@ def analyze_weather_trend(
             pass
     local_hour_frac = local_hour + local_minute / 60
 
+    daily_dates = daily.get("time", []) or []
+    daily_highs = daily.get("temperature_2m_max", []) or []
+    if local_date_str in daily_dates:
+        try:
+            local_day_idx = daily_dates.index(local_date_str)
+            local_day_high = _sf(
+                daily_highs[local_day_idx]
+                if local_day_idx < len(daily_highs)
+                else None
+            )
+            if local_day_high is not None:
+                current_forecasts["Open-Meteo"] = local_day_high
+        except Exception:
+            pass
+        forecast_highs = [h for h in current_forecasts.values() if h is not None]
+        forecast_high = max(forecast_highs) if forecast_highs else None
+        forecast_median = (
+            sorted(forecast_highs)[len(forecast_highs) // 2] if forecast_highs else None
+        )
+
     # === DEB ===
     deb_prediction = None
     deb_raw_prediction = None

tests/test_deployment_runtime_config.py

@@ -47,3 +47,9 @@ def test_scan_terminal_backend_timeout_returns_before_next_proxy_abort():
 
     assert 'POLYWEATHER_SCAN_TERMINAL_PROXY_TIMEOUT_MS || "40000"' in route_source
     assert scan_terminal_config.SCAN_TERMINAL_BUILD_TIMEOUT_SEC <= 30
+
+
+def test_probability_engine_uses_enriched_multi_model_snapshot():
+    source = (ROOT / "web" / "analysis_service.py").read_text(encoding="utf-8")
+
+    assert 'raw["multi_model"] = mm' in source

tests/test_trend_engine.py

@@ -137,6 +137,32 @@ class TestMuCalculation:
         assert mu is not None
         assert mu >= 33.0, f"μ should be >= actual max (33°C), got {mu}"
 
+    @patch("src.analysis.trend_engine.calculate_dynamic_weights", return_value=(None, ""))
+    @patch("src.analysis.trend_engine.get_deb_accuracy", return_value=None)
+    @patch("src.analysis.trend_engine.update_daily_record")
+    def test_mu_uses_city_local_date_daily_high(self, _udr, _deb_acc, _dw):
+        """Cached daily arrays may include yesterday first; μ must use the city-local target date."""
+        data = _make_weather_data(
+            cur_temp=25.0,
+            max_so_far=25.0,
+            om_today_high=24.0,
+            ens_median=None,
+            ens_p10=None,
+            ens_p90=None,
+            local_time="2026-05-28 09:30",
+            recent_temps=[("09:00", 25.0), ("08:00", 24.0), ("07:00", 23.0)],
+            multi_model={},
+        )
+        data["open-meteo"]["utc_offset"] = 8 * 60 * 60
+        data["open-meteo"]["daily"]["time"] = ["2026-05-27", "2026-05-28"]
+        data["open-meteo"]["daily"]["temperature_2m_max"] = [24.0, 31.0]
+        data["open-meteo"]["hourly"]["time"] = [f"2026-05-28T{h:02d}:00" for h in range(24)]
+
+        _, _, sd = analyze_weather_trend(data, "°C", "wuhan")
+
+        assert sd["current_forecasts"]["Open-Meteo"] == 31.0
+        assert sd["mu"] is not None and sd["mu"] >= 30.0
+
 
 # ─── Tests: Dead Market ───
 

web/analysis_service.py

@@ -737,6 +737,7 @@ def _analyze(
         mm_hourly = _weather.fetch_multi_model(lat, lon, city=city, use_fahrenheit=is_f)
         if mm_hourly and mm_hourly.get("hourly_times"):
             mm = {**mm, **mm_hourly}
+    raw["multi_model"] = mm
     risk = CITY_RISK_PROFILES.get(city, {})
     network_snapshot = (
         build_country_network_snapshot(city, raw)