Experimental Great Lakes Short-Term Ice Forecast

DEMO: Nowcast for February 18, 2021 & 5-Day Forecast

How to Read the Forecast

Time Scale

The 5-day forecast provides hourly estimates of future conditions, beginning with a nowcast of present lake conditions based on model simulations using best estimates for meteorological conditions. This product is refreshed four times per day with the latest weather forecast conditions (Midnight, 6 am, 12 pm, 6pm UTC). The model captures lake condition changes every minute. 

Base Layer & Color Scale

Select either ice concentration or ice thickness as the map’s base layer. Concentration indicates the approximate % coverage of ice over a given area. After selecting the base layer, select either a continuous color scale (Gradient Color Scheme) or a categorical color scale (NIC Color Scheme) developed by the National Ice Center that represents different thresholds of ice thickness. 

Additional Data Layers

After choosing the base layer, select additional data layers including winds, ice velocity, and water temperature. For the winds and ice velocity data layers, the length of the arrows indicate speed in a given region–the longer the arrow, the faster the winds. The length of a grey arrow representing 10kn is depicted for comparison for wind direction. Ice velocity is similarly depicted by the colored arrows–an arrow representing 0.5 kn is pictured for reference. 

Water temperature is displayed by contour lines labeled as 0, 2, or 3 degrees Celsius. The darker blue indicates colder temperatures. 

Geographic View

Select a preferred geographic view for the forecast by clicking through tabs at the top of the map graphic. In addition to a basin-wide view, specific geographic areas have been offered because they have been identified by users as regions that pose great challenges to winter navigation. 

About the Forecast

This experimental ice forecast is a component of the coupled lake hydrodynamic-ice system, the Great Lakes Operational Forecast System (GLOFS) produced by scientists at CIGLR and the NOAA Great Lakes Environmental Research Lab. GLOFS models are currently in transition from research to operations at NOAA NOS/CO-OPS (or potentially NIC) to provide the first-ever, short-term (i.e., 5 days) ice forecast guidance.