84th AMS Annual Meeting

Thursday, 15 January 2004
Improving the Great Lakes 30-day ice forecast
Room 4AB
Sheldon Drobot, The National Academies, Washington, DC
The U.S. Navy/NOAA National Ice Center (NIC) is responsible for issuing 30-day forecasts of ice conditions on the Great Lakes. Based on historical findings that variations in the ice cover are related to air temperatures, the NIC product currently utilizes estimates of freezing degree days (FDDs; a temperature proxy), analyst knowledge, some teleconnection data (NAO and ENSO), and analogues of previous years to issue a 30-day forecast. The end result is a single map of forecast ice conditions based on semi-quantitative information. Here, a new quantitative statistical model is introduced to forecast ice conditions based solely on FDDs, teleconnection data, and preceding ice conditions. The model output also provides uncertainty information, so that probability maps can be created to convey a range of ice information to users. This presentation discusses model development and shows sample maps that convey uncertainty information in the 30-day forecast.

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