The landfall of Tropical Storm Ida: Frontal structures and boundary layer variability

The landfall of Tropical Storm Ida (10 November 2009) was sampled by four Doppler radars and extensive surface observational platforms deployed by several universities. As Ida made landfall, a slow weakening was observed as the storm moved over a cooler water surface near the Gulf Coast. The landfall of Ida was accompanied by relatively heavy rain that was continually initiated near the coast east of Mobile Bay over an extended time period. This forcing was provided by a distinct quasi-stationary frontal boundary that eventually moved inland and was sampled by the extensive surface mesonet, Doppler radars, and a Doppler wind profiler. This paper will present a detailed analysis of two very distinct fronts that exhibited sharp thermal contrasts of about 3 deg C. In addition, variations in boundary layer structures determined by surface and radar measurements, and their variations around the land-water interface will be examined along the Gulf Coast into Mobile Bay.