Lake Ontario Operational Forecast System (LOOFS)

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)

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Water Level
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Water Temperature
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(Please click on the categories below to access animated map plots)
Nowcast Nowcast Nowcast Stations Nowcast
Forecast Guidance Forecast Guidance Forecast Guidance Stations Forecast Guidance
      Field Nowcast
      Field Forecast Guidance

The Lake Ontario Operational Forecast System (LOOFS) is a NOAA project aimed at providing improved predictions of water levels, currents and water temperatures in Lake Ontario to the user communities. Similar systems are operational in the other 4 Great Lakes as well. Collectively these form the Great Lakes Operational Forecast System (GLOFS). The objective of GLOFS is to produce nowcast and forecast guidance (displayed out to 24 hours) of total water level, current velocity, and water temperatures in the Lakes to be used by the commercial shipping , recreational boating and emergency response communities. GLOFS nowcast and forecast guidance will provide an increased margin of safety and maximize the efficiency of commerce throughout the Lakes. For more information on GLOFS, please click here.

Nature of GLOFS Products
The Great Lakes Operational Forecast System (GLOFS) has been implemented by NOAA's National Ocean Service (NOS) to provide the maritime community with improved short-term predictions of water levels, water currents and water temperatures of the Great Lakes. GLOFS uses a numerical hydrodynamic model to generate these predictions. Therefore, these predictions should be considered as computer-generated nowcast and forecast guidance. For more detailed information related to the OFS disclaimer, please visit at the Disclaimers web page.