A climatological analysis of deep convection interactions with the Lake Erie marine boundary layer
WSR-88D radar, surface, buoy, and rawinsonde observations collected from 2001-2009 were used to characterize atmospheric conditions upwind of the lake and within the marine boundary layer (MBL) as well as storm behavior over Lake Erie. In total, 111 cases of pre-existing convection (>45 dBZ) moving over Lake Erie during the 9-year period were identified. Of these storms, 30 were classified as ‘clusters', 25 ‘isolated', 34 ‘linear' and 22 ‘complex.'
Analyses revealed that noteworthy systematic changes in the maximum reflectivity of the systems were generally not observed until 60 minutes over the water. Cluster and isolated systems tended to weaken in cases where the MBL was convectively unfavorable (i.e. reduced surface-based instability), while linear and complex systems tended to be less affected by the MBL, regardless of its characteristics. Linear correlations between the various environmental parameters and changes in maximum reflectivity of the convective system were generally weak, suggesting that no single parameter fully explained the observed storm behavior over the lake. However, isolated systems showed a statistically significant correlation between storm weakening and colder over-lake surface air temperature conditions. Analysis of linear systems indicated a statistically-significant weakening trend as low-level (3 km) vertical wind shear decreased. The results of statistical analyses of parameter/storm intensity relationships, including multivariate and non-linear analysis, as well as an individual case study examining the effect of the MBL on a mature squall line, will be presented.