OBSERVATIONS AND SIMULATIONS OF MULTI-DAY MIDLATITUDE CORRIDORS OF HEAVY WARM-SEASON RAINFALL

Abstract:

Multiday corridors of heavy warm-season precipitation, with only modest daily latitudinal drifts of heaviest rainfall, frequently yield extreme total precipitation amounts (e.g., > 250 mm) which result in both short-term and seasonal impacts on the regional hydrological cycle. The physical processes that influence the localization and intensity of these precipitation corridors often have an adverse effect on precipitation in surrounding areas, which increases their regional hydrologic importance. In this talk, we review observational studies of the climatological aspects of these multiday heavy midlatitude precipitation corridors confined to narrow latitudinal widths (< 5 degrees). We also present sensitivity studies with high-resolution convection-allowing models. Comparisons of these different simulations allows us to examine the relative importance of 1) external large-scale factors and 2) internal factors related to repeated precipitation episodes over the same location on determining the intensity and longevity of the heavy precipitation corridors.