Coastal & Great Lakes Conditions Forecast

Notice of NOS OFS product changes

Effective on or about October 25, 2022 beginning at 18z Coordinated Universal Time (UTC), the NOAA/National Ocean Service’s framework for Operational Forecast Systems (OFS) will be updated to version 3.5. The update includes:

  1. Changing the NOS directory structures on NOMADS/FTPPRD from com/nos to com/nosofs;
  2. Replacing the existing POMGL-based, coarse resolution, structured grid Lake Superior Operational Forecast System (LSOFS) and Lake Ontario Operational Forecast System (LOOFS) with FVCOM-based, high-resolution, unstructured grid LSOFS and LOOFS. As a result, the new LOOFS and LSOFS products will be disseminated on NOMADS/FRPRPD under com/nosofs, and the existing LOOFS and LSOFS products on NOMADS/FTPPRD under com/glofs will no longer be disseminated; the new products will be available under com/nosofs;
  3. The National Water Model (NWM) products are used as freshwater inputs for all NOS OFS except Cook Inlet OFS (CIOFS);
  4. Hybrid HRRR and NDFD will be used as meteorological forcing conditions for all Great Lakes OFS;
  5. Product delivery time for LEOFS, LMHOFS, LOOFS, and LSOFS will be delayed about 1-2 hours compared to the existing delivery time. More details regarding this update can be found in the corresponding Science Change Notice which will be available at

NOAA provides forecast guidance of oceanographic information to help mariners safely navigate their local waters. This national network of hydrodynamic models provides users with operational nowcast and forecast guidance (out to 48 hours) on parameters such as water levels, water temperature, salinity, and currents. These forecast systems are implemented in critical ports, harbors, estuaries, Great Lakes and coastal waters of the United States, and form a national backbone of real-time data, tidal predictions, data management and operational modeling.

  • Operational Forecast Regions:

  • Marine Channel Forecast

    A product designed to aid local pilots by providing them with meteorological and oceanographic forecasts along the marine channels.
A cargo ship stacked with shipping containers on open water.
Cargo ships like this one rely on NOAA ocean conditions forecasts for safe navigation.