Examining the Impacts of Great Lakes Temperature Perturbations on Simulated Precipitation in the Northeastern United States

Abstract Most inland water bodies are not resolved by general circulation models, requiring that lake surface temperatures be estimated. Given the large spatial and temporal variability of North American Great Lakes, such estimations can introduce errors when used as lower boundary conditions for dynamical downscaling. Lake (LSTs) influence moisture heat fluxes, thus impacting precipitation within immediate region potentially in regions downwind lakes. For this study, Advanced Research version Weather Forecasting Model (WRF-ARW) was to simulate over six New England states during a 5-yr historical period. The model simulation repeated with perturbed LSTs, ranging from 10°C below above baseline values obtained reanalysis data, determine whether inclusion erroneous LST has an impact on simulated synoptic-scale features. Results show is statistically correlated perturbations, but falls wet–dry line larger bimodal distribution. Wetter occur north drier south increasing particularly warm season. differences coincide large-scale anomalous temperature, pressure, patterns. Care must therefore taken ensure reasonably accurate Lakes simulating precipitation, especially southeastern Canada, Maine, mid-Atlantic region.