Cyclone Climatology of the Great Lakes

A historical cyclone dataset was constructed for the period 1900 to 1990 from those cyclones passing over the Great Lakes with a central pressure ≤992 mb. This dataset was used to address the following five research topics: a) the trends and fluctuations in the characteristics of cyclones, b) the balance between cyclone frequency and intensity, c) the sensitivity of cyclone characteristics to climate variables, particularly temperature and precipitation regimes, d) the preferred tracks of cyclones passing over the region and changes over time, and e) the influence of the Great Lakes on passing cyclones. This study documents a statistically significant increase in the frequency of strong cyclones over the Great Lakes during the 20th century in both November and December. There are indications that a balance exists between cyclone frequency and intensity. The two major source regions for Great Lakes cyclones are Colorado and Alberta, Canada. An analysis of changes in cyclone characteristics, temperature, and precipitation yields a positive relationship between cyclone frequency and precipitation. This research also provides climatological evidence (as opposed to case studies or models) of the important influence of the Great Lakes on passing cyclones. Cyclones accelerate into the region, slow and deepen over the lakes, and then return to their prior speed and rate of deepening after they exit the region.published or submitted for publicationis peer reviewe