Authors: Andrew Ellis*, Virginia Tech, Michael Marston, Virginia Tech, Joseph Bahret, Virginia Tech
Topics: Climatology and Meteorology
Keywords: lake-effect, Great Lakes
Session Type: Paper
Start / End Time: 1:10 PM / 2:50 PM
Room: Truman, Marriott, Mezzanine Level
Presentation File: No File Uploaded
The North American Great Lakes regularly influence surface weather downwind. The effect can be great in fall and winter when southward migrating cold air passes over relatively warm lakes. Previous studies have resolved the synoptic atmospheric conditions conducive to the most impactful effect of the lakes in winter, lake-effect snowfall. However, an atmosphere conducive to lake effects may not necessarily translate to discernible modification of downwind surface weather, particularly late in a season when the thermal inertia extending from the preceding season has waned. This study approaches the characterization of cold season lake effects from the opposite direction of previous studies. Surface weather type data from an array of locations surrounding the Great Lakes are used to identify upwind cold, dry air passing over the lakes that was apparently modified to cold, moist air downwind. The result is 50-year records of pure lake-effect days for the eastern (Lakes Erie and Ontario) and western (Lakes Superior and Michigan) Great Lakes during the season November through April. Validating the results are synoptic atmospheric composites and co-variability with large-scale climate teleconnections. Presented is a lake-effect hydroclimatology using daily precipitation stations downwind of the two sets of lakes.