Air Mass Typing of Precipitation Events in the Northeastern Lower Peninsula of Michigan

Abstract: This study involves the deployment of a remote weather station near Atlanta, MI and analysis of the in-situ data using the redeveloped Spatial Synoptic Classification (SSC2). The six possible air mass types of the SSC2 are distinguished from one another by the following variables: temperatures and dewpoint temperatures at 04, 10, 16, and 22 EST, mean cloud cover, mean sea level pressure, diurnal temperature range, and diurnal dewpoint range. As this station is remote, the mean cloud coverage is computed using the station’s pyranometer to calculate a ratio of observed radiation to expected radiation at any given time. In order to classify these days as air masses, “seed days” are determined for the three air mass types that occurred over the region between June 25^th, 2018 and September 6^th, 2018. Because not all air mass types have occurred during the limited time frame, observations from nearby stations ranging from 2010-2016 are used to identify “seed days” for the remaining 3 air mass types, as well as for validation of the air mass classification at the remote weather station location. An analysis of the air mass type frequencies along with precipitation characteristics is presented.