NOAA S-111: Surface Water Current Forecasts for U.S. Coastal Waters

S-111 is an international hydrographic data standard for encoding surface water current forecasts. This collection contains forecast guidance from NOAA's Operational Forecast Systems and the Global Real-Time Ocean Forecast System (GRTOFS) for U.S. coastal waters and the Great Lakes, encoded as HDF-5 files. Forecasts are generated four times daily for most models and represent currents at a depth of 4.5 meters or half the water column depth.

Use Cases

• Maritime route optimization based on forecasted surface current vectors.
• Validating hydrodynamic models using operational forecast system outputs.
• Analyzing coastal current patterns based on gridded forecast arrays for specific geographic tiles.
• Integrating standardized S-100 hydrographic data into nautical charting or GIS systems.

Strengths

• Data conforms to the S-100 international hydrographic data standard, ensuring interoperability.
• Forecasts are generated four times daily for most models, providing frequent updates.
• Files are geospatially subset into tiles matching NOAA Electronic Navigational Chart cells, aiding localized analysis.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count and total dataset size are unknown, which may limit suitability assessment.
• Last update date is unknown; freshness unverified.

Provenance

Source

NOAA/NOS Operational Forecast Systems and NCEP Global Real-Time Ocean Forecast System (GRTOFS).

Collection Method

Output from operational hydrodynamic nowcast and forecast modeling systems.

Freshness

Model runs occur four times per day for most systems; GRTOFS updates once per day.

Geography

U.S. coastal waters and the Great Lakes, with some offshore areas from GRTOFS.