Observations of Tropical Storm Fay

The University of Alabama in Huntsville Mobile Integrated Profiling System (MIPS) and Mobile Alabama X-Band (MAX) were deployed northeast of the Mayport Naval Station just outside the Jacksonville city limits during the landfall of Tropical Storm Fay. Due to its extremely slow movement Fay was sampled for about 3 days, 20-22 August 2008. Over this period over 10 inches of rain were recorded, a peak wind gust of 25 ms-1, and several tornadic rainbands were sampled in the dual-Doppler domain. A Parsivel disdrometer was also deployed on this system and will be used in conjunction with MAX vertical pointing data and MIPS to examine the dropsize distribution of each band as well as other features that passed over the site.

Due to the close proximity of the Jacksonville WSR-88D Radar (KJAX, 28km to the WNW) a dual-Doppler analysis of a tornadic rain band will be performed to examine the kinematic and microphysical structure. Preliminary measurements indicate that differential friction may have played a role in generating cyclonic shear along the coast line that is hypothesized to have enhanced potential for tornadogenesis. Indeed, several tornadoes were reported very close to or within the dual Doppler domain. This analysis will reveal details of the boundary layer structure prior to and during the passage of the rainband.