Extended Abstract (520K)P2.16
Numerically Simulated Interactions Between a Precipitating Synoptic System and Lake-Effect Snowbands over Lake Michigan
Katy L. Fitzpatrick, South Dakota School of Mines and Technology, Rapid City, SD; and M. R. Hjelmfelt, W. J. Capehart, and D. A. R. Kristovich
Wintertime months allow for the phenomenon of lake-effect snowfall events over the Great Lakes. Previous numerical simulations indicate the difficulty of accurately representing lake-enhanced events, especially as the lake-effect is enhanced with the added complexity of interactions with synoptic systems. The case of 4-5 December 1997 was a scenario with lake enhancement by a precipitating closed low pressure system which naturally seeded the low-level lake-effect snowbands, resulting in enhanced snowfall accumulation. Conveniently, the Lake-Induced Convection Experiment (Lake-ICE) had initiated operations starting at 00Z on 5 December 1997 and continuing through 00Z on 6 December 1997, which allowed verifications of simulation results by observations.
Synoptic and Lake-ICE observations were used as inputs for the Fifth Generation Penn State/National Center for Atmospheric Research Mesoscale Model Version 3 (MM5V3). This paper discusses the decisions concerning physics schemes (both micro- and mesoscale), and model gridding to ensure high-resolution meteorological phenomenon were accurately represented. Model output correctly captured the layered cloud features; specifically, model results demonstrated natural seeding. The simulations were compared to Lake-ICE weather analyses, and thermodynamic and cloud physics observations for verification. Further simulations and analyses to examine physical processes and numerical prediction issues in progress will also be presented.
Poster Session 2, Tuesday Posters
Tuesday, 13 January 2004, 9:45 AM-11:00 AM, Room 4AB
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