Preliminary Investigation of Selected Radar Patterns Associated with Local Maximum Wind Gusts in Rainbands of Landfalling Tropical Cyclones

Outer rainbands associated with landfalling tropical cyclones often bring the first initial tropical storm or hurricane-force gusts prior to the arrival of the storm core. Also, for locations on the periphery of the storm, outer rainbands may produce the strongest winds observed there during the storm landfall event.

In operations, Doppler radar data is used by local National Weather Service offices to issue warnings for initial tropical storm-force winds associated with these outer squalls. Are there preferred locations within these rainbands where localized maximum wind gusts are often found?

In this preliminary investigation, maximum wind measurements from coastal monitoring stations, such as C-MAN and ASOS, will be temporally and spatially matched with WSR-88D reflectivity and velocity patterns within rainbands associated with a few nearby landfalling tropical cyclones. These tropical cyclones will be selected from the WSR-88D archive period of 1994 to 2013.

Some of the questions to be addressed at the conference will include: 1) Where do the maximum wind gusts most often occur within rainbands? 2) Are these gusts most often found along the leading edge of the rainband in the vicinity of the gust front? 3) Are these gusts most often found within cores of heavy precipitation? 4) Are many of these maximum gusts associated with some type of vortex-like feature? 5) Are some of these maximum wind gusts found within relatively weak reflectivity features or even found between rainbands? 6) Are there certain velocity features, such as low-level jets, which often appear around the time of these maximum wind gusts?

If this preliminary study shows promising results, a more in-depth evaluation will occur over the next couple of years using a larger selection of landfalling storms from the 1994 – 2013 WSR-88D dataset archive.