overpredict
verb
over·pre·dict ˌō-vər-pri-ˈdikt 
overpredicted; overpredicting; overpredicts
transitive verb
: to predict by an amount that exceeds the actual value
overpredict inflation
overprediction
ˌō-vər-pri-ˈdik-shən
noun 
Example Sentences
Recent Examples on the Web As a result, meteorologists tend to overpredict snow. 
Todd Nelson, Star Tribune, 13 Jan. 2021 Because of this lack of data, computer models that simulate present and future climates overpredict how much sunlight reaches the ocean surface compared to what satellites actually observe. Thomas Hill, The Conversation, 19 June 2020 In the case of winter storm Stella, the American model massively overpredicted snowfall. Jeff Halverson, Washington Post, 6 Apr. 2018
Todd Nelson, Star Tribune, 13 Jan. 2021 Because of this lack of data, computer models that simulate present and future climates overpredict how much sunlight reaches the ocean surface compared to what satellites actually observe. Thomas Hill, The Conversation, 19 June 2020 In the case of winter storm Stella, the American model massively overpredicted snowfall. Jeff Halverson, Washington Post, 6 Apr. 2018 Word History
First Known Use
1954, in the meaning defined above