NOAA tidal water-level anomaly intelligence (daily)

Every NOAA coastal water-level station's observed-minus-predicted tidal residuals over the trailing 24 complete UTC hours, transformed into a ranked surge/drawdown intelligence digest. Each row is one station: hourly residual statistics (mean, max, min, std in meters; observed minus astronomical prediction, so the ordinary tide is removed), counts of surge/drawdown hours at +/-0.3 m, sustained-event flags (3-hour running mean at +/-0.5 m), the residual least-squares trend (m/hour) flagging building surge situations, and a documented 0-100 anomaly_score ranked as anomaly_rank with tiers extreme/high/elevated/normal. Stations need >= 18 of 24 hours with both observed and predicted values; stations with no hourly predictions (mostly Great Lakes gauges) are excluded by design. Primary key: station_id. Cadence: daily; as_of is the window end (last complete UTC day), so identical input produces an identical content hash. Caveats: observations are preliminary and may be revised by NOAA; anomalies are non-astronomical water-level deviations, not weather forecasts. NOAA tide data is U.S. federal public domain — commercial_use = yes. Sample use: filter anomaly_tier in ('extreme','high') for stations seeing real surge right now, or track one station's residual_trend across snapshots for a building surge.