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Data Sources & Methodology

Where the dashboard gets its data, how measurements differ from forecasts, and what to check before paddling.

Bellingham Bay Conditions combines public sensor observations, NOAA tide predictions, NOAA ocean-model guidance, local pressure-gradient interpretation, and third-party webcams. These sources update at different times. Every displayed measurement or forecast should be read with its own timestamp and source label.

Data sources

Measured observations

Wind speed, gusts & direction

NOAA National Data Buoy Center (NDBC) · Se’lhaem Bellingham Bay buoy, station 46118.

The dashboard retrieves reported buoy winds and displays the observation time. Buoy instruments can stop reporting or become delayed.

View NOAA buoy station ↗
Predicted water level

Next high or low tide

NOAA CO-OPS · Bellingham tide station 9449211.

Displays the next predicted high or low tide and height in feet relative to mean lower low water (MLLW). Predictions are not direct readings of current water level.

View official tide predictions ↗
Observation preferred · model fallback

Surface-water temperature

University of Washington NWEM and NANOOS ERDDAP provide access to Se’lhaem observations. When suitable current observations are unavailable, the dashboard can use NOAA SSCOFS modeled surface temperature instead.

Observed and modeled readings are not interchangeable. The dashboard labels NOAA model estimates “modeled” and shows their model-valid time. Model temperature is estimated over representative Bellingham Bay grid nodes, not measured by a thermometer at the launch site.

UW NWEM dataset ↗ · NANOOS ↗

Modeled forecast

Surface-current map & streamlines

NOAA Salish Sea and Columbia River Operational Forecast System (SSCOFS), using the FVCOM ocean model.

The dashboard processes a geographic subset of NOAA model files into a 24-hour current-speed and flow visualization at three-hour intervals. Colored speeds and streamlines represent modeled guidance, not direct observations. Animated streamline motion indicates flow patterns and should not be interpreted as exact particle-travel speed.

About NOAA SSCOFS ↗
Measured observations + local heuristic

South-wind pressure gradient

NOAA Aviation Weather Center METAR pressure observations from Arlington Municipal Airport (KAWO) and Eastsound / Orcas Island Airport (KORS).

The displayed gradient is Arlington pressure minus Eastsound pressure, in inches of mercury (inHg). The dashboard uses a freshness check (both reports within 90 minutes, report times within 35 minutes). Interpretations of potential southerly wind strength follow a rough local paddling rule of thumb—not a NOAA forecast or a validated prediction.

NOAA Aviation Weather API ↗ · Local paddling guide ↗

Third-party live video

Bay webcams

Port of Bellingham camera feeds: Marine Park Panorama; Zuanich Point Park; and Marine Park facing Post Point.

Embedded live video is provided by the camera operators through YouTube. Availability, playback, and camera timestamps are controlled by those operators, not by this dashboard.

Port camera information ↗ · Marine Park ↗ · Zuanich Point ↗ · Post Point view ↗

Mapping

Map tiles and display

OpenStreetMap contributors provide geographic basemap information; Leaflet provides the interactive map interface.

The colored NOAA currents are an additional model-data visualization over the basemap; they do not originate from OpenStreetMap.

OpenStreetMap attribution ↗ · Leaflet ↗

Official safety resources

Marine forecast and alerts

National Weather Service marine forecasts, watches and warnings should be checked separately before entering the water.

The dashboard's indicators are context, not substitutes for an official forecast, hazards report, or direct assessment at the launch site.

NWS Seattle forecast office ↗

How the dashboard works

  • Live observations: Cloudflare Pages API endpoints retrieve buoy and airport observations; the page periodically refreshes its displayed values. A page reload is not the same thing as a new sensor observation.
  • Temperature fallback: Fresh local buoy observations take priority. If those observations are unavailable or too old, a recent SSCOFS surface-temperature estimate may be shown and is explicitly identified as modeled. If neither is suitable, the card shows an unavailable value.
  • Ocean model: GitHub Actions retrieves and processes NOAA SSCOFS forecast data on a scheduled basis (configured approximately every six hours), then publishes model products to the dashboard. The animated map offers nine snapshots across 24 hours, at three-hour steps.
  • Forecast-valid time: The time for which NOAA predicts conditions can differ from the file-processing time and the current clock time. Read those timestamps separately.
  • Pressure gradient: A reported pressure difference is an observation-based calculation. The associated south-wind range is an informal local heuristic, and is meaningful only in a suitable regional southerly pattern.
  • Webcams: Video players request third-party streams directly; the dashboard does not operate or guarantee the cameras.

Limitations and safe use

For situational awareness only. This dashboard is not an official navigation, marine-safety, or voyage-planning service. NOAA model guidance can differ from actual winds, waves, currents and water temperatures. Airport pressure is not a local marine wind measurement. Weather, visibility, traffic, sea state and current conditions can change rapidly. Always consult current official forecasts and warnings, local observations, and your own on-water judgment before paddling.
Questions or discrepancies? If a reading seems incorrect, compare its timestamp and original source using the links above. Source outages or model delays can cause blank or stale values. Return to the dashboard.