Updating Great Lakes Observations with New NOAA Climate Normal Statistics

Funded by NOAA CPO

Project Summary

GLISA’s station and division and climatologies complement existing NOAA-based statistics and provide detailed region-specific information. The climatologies are currently calculated using NOAA data for temperature and precipitation for the current 1981-2010 climate normals period and the 1951-1980 reference period to illustrate temporal trends.

GLISA is in the process of updating these climatologies and accompanying resources to conform with the new international standard (i.e., climate normal period of 1991-2020). In addition to updating the historical observations, GLISA is also integrating future temperature and precipitation projections from the University of Wisconsin-Madison Nelson Institute’s Regional Climate Model Version 4 (UW-RegCM4) into our climate division pages. 

For relative temporal trends, different normal reference periods have now been utilized by the World Meteorological Organization (WMO), NOAA, and NASA, creating a challenge for using these periods. In consultation with our Science Advisory Committee (SAC), GLISA has decided to process and update historical temporal trend information using two reference periods, 1951-1980 and 1961-1990. GLISA will then work with the Practitioner Working Group (PWG) to understand the best ways to integrate these climate normal statistics into GLISA’s products and services.

Project Accomplishments

  • Climate trends for precipitation and temperature calculated for the Climate Normal period of 1991-2020 in station and division climatologies, Climate Change in the Great Lakes Region 2-pager and other resources. 
  • Updated historical trend information using two reference periods, 1951-1980 and 1961-1990.

GLISA Contribution

GLISA is leading and executing this project in consultation with the Science Advisory Committee (SAC) and the Practitioner Working Group (PWG) to make key decisions.

GLISA Contact

Omar Gates, Climatologist, gateso@umich.edu