HR: 0800h
AN: H31B-0355    [Abstracts]
TI: The Environmental Parameters That Influence Simulated Convective Storm Precipitation: Results From a Large Parameter Space Study
AU: * Kirkpatrick, C
EM: cody@nsstc.uah.edu
AF: University of Alabama in Huntsville, 320 Sparkman Dr., Huntsville, AL 35899,
AU: McCaul, E W
EM: mccaul@usra.edu
AF: Universities Space Research Association, 6700 Odyssey Dr., Ste. 203, Huntsville, AL 35806,
AU: Cohen, C
EM: cohen@usra.edu
AF: Universities Space Research Association, 6700 Odyssey Dr., Ste. 203, Huntsville, AL 35806,
AB: Relationships between environmental conditions and the precipitation characteristics of simulated storms in a large eight-dimensional parameter space study are investigated. Specifically, we explore which environmental parameters are associated with the greatest production of rain and hail, both aloft and near the surface. The rainwater and hail mixing ratios for each experiment are averaged during the second hour of 2 h simulations to assess the precipitation production of each storm. Multiple linear regressions of the mixing ratios to the environmental parameters are then performed, to identify the parameters most correlated to the production of rain and hail. Although our results do not characterize the amount of point rainfall that would be observed from a particular storm, relationships between storm rainfall and properties of the environmental profile are found. The environmental temperature, related to atmospheric precipitable water (PW), exerts considerable influence over the precipitation characteristics of the simulated storms. When atmospheric PW increases, storms generally produce more rain and hail aloft, but less hail is observed near the surface owing to the increased depth of the melting layer. The ambient shear profile also affects the amount of rainfall, since general storm morphology and evolution are affected by the environmental wind shear. The level of free convection (LFC) and vertical distribution of buoyancy have lesser influence. Rain and hail production exhibit reduced predictability (in a linear regression sense) compared to other storm properties, such as updraft intensity. These findings demonstrate the degree of influence that environmental conditions can have on convective storm organization and may offer insight into the difficulties associated with forecasting convective rainfall.
UR: http://space.hsv.usra.edu/COMPASS/
DE: 1840 Hydrometeorology
DE: 1854 Precipitation (3354)
DE: 3314 Convective processes
DE: 3329 Mesoscale meteorology
SC: Hydrology [H]
MN: 2007 Fall Meeting