Great Lakes water levels at or above average for next 6 months

NOAA and Army Corps issue forecast, consider El Niño potential impact

Scientists from NOAA, the U.S. Army Corps of Engineers and Environment Canada have issued a six-month forecast for water levels to be at or above average on Lake Superior, Michigan, Huron, and Erie into spring of 2016. Lake Ontario water levels are expected to remain close to monthly averages. However, the impacts of the anticipated strong El Niño and other atmospheric anomalies on the forecast are difficult to predict.

The water levels of the Great Lakes have always been dynamic. However, the drop in water levels in the late 1990s that culminated in a record low level for Lakes Michigan and Huron in January 2013 and an unprecedented two-year rebound in water levels that resulted in above average levels on all lakes by the fall of 2014 have led hydrologists to look more closely at how atmospheric patterns affect water levels.

The primary drivers of seasonal water level change are precipitation, evaporation, and runoff. Part of the uncertainty in long-term future water level projections stems from the challenge of predicting over-lake precipitation, runoff, and over-lake evaporation, while also incorporating the effects of large-scale climate forces, such as the 2014 Arctic polar vortex anomaly and El Niño.

In a recent forecast update, NOAA’s Climate Prediction Center stated El Niño will likely peak in the Northern Hemisphere during the winter of 2015-16, and is expected to transition to a neutral period during the late spring or early summer of 2016.  NOAA’s Winter Outlook (Dec. – Feb.) favors warmer than normal temperatures for most of the Great Lakes region, and precipitation is most likely to be below normal for the eastern half of the basin. Warmer conditions may reduce total snowfall and ice cover in the Great Lakes this winter. With the return of above average levels to most of the lakes, there is additional risk of localized flooding from severe storms and wind events.

El Niño associated impacts have varied in the past in the Great Lakes region. The 1997-98 El Niño resulted in a very warm winter across the basin (+ 5.0 degrees Fahrenheit above normal) while the El Niño in 1965-66 resulted in temperatures below average in much of the basin. Other atmospheric anomalies can also affect the region’s winter weather and can either enhance or diminish impacts of a strong El Niño.  

NOAA and its partners collaborate extensively to forecast Great Lakes water levels every month. These forecasts are based on information from continuous operational water level and meteorological monitoring networks provided by U.S. and Canadian federal agencies, as well as research-oriented monitoring stations of partner academic institutions. The water level stations maintained by the NOAA/National Ocean Service Center for Operational Oceanographic Products and Services (CO-OPS) provide one of the longest high quality hydrometeorological data sets in North America, with data beginning in 1860. Research and monitoring of Great Lakes water levels and regional meteorological conditions is an important part of NOAA’s mission to understand and predict changes in climate, weather, oceans, and coasts.

More information

·  Midwest Climate Center Great Lakes El Nino Outlook

·  NOAA Great Lakes Water Levels

·  NOAA-GLERL Great Lakes Water Levels factsheet

·  NOAA Real-Time Water Level Observations

·  NOAA Great Lakes Water Level Hydro-Climate Dashboard

·  NOAA Lake Level Viewer

·  U.S. Army Corps of Engineers Monthly Bulletin of Great Lakes Water Levels

·  New NOAA research on Lake Michigan water levels 2013-2014

For more information, please contact Monica Allen, director of public affairs for NOAA Research, at 301-734-1123 or by email at monica.allen@noaa.gov