Precipitation Distribution and Kinematic Structure of Hurricane Hugo Over the Carolinas

An investigation of the precipitation distribution and kinematic structure of Hurricane Hugo over land was conducted for a 19-hour period beginning with landfall of associated precipitation. Surface kinematics and thermodynamics, NWS radar reflectivity observations, and hourly precipitation data HPD were compared to investigate the nature of the precipitation systems associated with Hugo. Surface data over Georgia, South Carolina, North Carolina, and Virginia from the NWS, AWS, and FAA stations was supplemented by power plant data. A stationary band complex SBC, observed to the left of Hugos track, was the predominate feature of radar imagery. This feature resulted in a storm-total rainfall maximum to the left of Hugos track. Heavy amounts of hourly rainfall 20 mm occurred within the SBC from 0500 UTC until 1000 UTC, and an equivalent potential temperature minima is associated with the SBC after landfall of Hugo. A regression equation was constructed to investigate the hourly precipitation for select land stations. The results indicate that over 37 of the variability in the HPD was accounted for when precipitation was occurring during Hugo. The distance to the eyewall contributed significantly to the variability of precipitation over land, in this case. It was found that terrain slope, surface wind speed, surface wind direction, and surface wind convergence were generally uncorrelated to hourly precipitation. However, when the data set was separated into geographic regions, terrain slope increased in importance from the coast to the mountains while wind speed decreased in importance.