Cook Inlet Operational Forecast System (CIOFS)

Effective on May 20, 2020 beginning at 18z Coordinated Universal Time (UTC), two major changes for NOS OFS datasets on THREDDS will be implemented. Please see the Service Change Notice for details

1. Retention period change - Only the most recent 31 days of OFS output files will be available on CO-OPS THREDDS.

2. File structure changes - To improve THREDDS performance related to file access and data aggregation

(Please click on the map pins below to access the time series plots)

Tide Icon
Water Level
Winds Icon
Water Temperatuer Icon
Water Temperature
Salinity Icon
Currents Icon
(Please click on the categories below to access animated map plots)
Nowcast Nowcast Nowcast Nowcast Nowcast
Forecast Guidance Forecast Guidance Forecast Guidance Forecast Guidance Forecast Guidance

For decades, mariners in the United States have depended on NOAA's Tide Tables for the best estimate of expected water levels. These tables provide accurate predictions of the astronomical tide (i.e., the change in water level due to the gravitational effects of the moon and sun and the rotation of the Earth); however, they cannot predict water-level changes due to wind, atmospheric pressure, and river flow, which are often significant.

To better serve maritime community, a new three-dimensional Cook Inlet Operational Forecast System (CIOFS) was developed by the NOAA/National Ocean Service/Office of Coast Survey in a joint project with the NOAA/NOS/Center for Operational Oceanographic Products and Services (CO-OPS) and the NOAA/National Weather Service/National Centers for Environmental Prediction (NCEP) Central Operations (NCO) using Rutgers University's Regional Ocean Modeling System (ROMS). CIOFS generates water level, wind, water temperature, salinity, and current nowcast and forecast guidance out to 48 hours, four times per day. Aerial animations of the Cook Inlet, as well as time series at particular stations or points of interest, are available for over 44 locations for the five parameters (water level, wind, currents, water temperature, and/or salinity). CIOFS will assist U.S. port authorities and mariners in efficiently navigating the Cook Inlet without compromising safety.

CIOFS runs on NOAA's High Performance Computing Systems (HPCS) in a standard Coastal Ocean Modeling Framework (COMF) developed by CO-OPS. As a result, CIOFS has direct access to National Weather Service operational meteorological products that it needs to run reliably.

For more detailed information about CIOFS, please click here.

For more information about ROMS, please click here.

Disclaimer: The Cook Inlet Operational Forecast System (CIOFS) has been implemented by NOAA's National Ocean Service (NOS) to provide the maritime user community with short-term predictions of water levels, water currents, and water temperatures in CIOFS model domain. CIOFS uses a numerical hydrodynamic model to generate the nowcast and forecast information; therefore, they should be considered as model-generated nowcast and forecast guidance. For more detailed information related to the OFS disclaimer, please visit at the Disclaimers web page.