Article: Pryor SC, Conrick R. Miller C, Tytell J, Barthelmie RJ; (2014) “Intense and Extreme Wind Speeds Observed by Anemometer and Seismic Networks: An Eastern US Case Study”, Journal of Applied Meteorology and Climatology, 53 (11): 2417-2429
Abstract: The scale and intensity of extreme wind events have tremendous relevance to determining the impact on infrastructure and natural and managed ecosystems. Analyses presented herein show the following. 1) Wind speeds in excess of the station-specific 95th percentile are coherent over distances of up to 1000 km over the eastern United States, which implies that the drivers of high wind speeds are manifest at the synoptic scale.
2) Although cold fronts associated with extratropical cyclones are a major cause of high-wind speed events, maximum sustained and gust wind speeds are only weakly dependent on the near-surface horizontal temperature gradient across the front. 3) Gust factors (GF) over the eastern United States have a mean value of 1.57 and conform to a lognormal probability distribution, and the relationship between maximum observed GF and sustained wind speed conforms to a power law with coefficients of 5.91 and -0.499. Even though there is coherence in the occurrence of intense wind speeds at the synoptic scale, the intensity and spatial extent of extreme wind events are not fully characterized even by the dense meteorological networks deployed by the National Weather Service. Seismic data from the USArray, a program within the Earthscope initiative, may be suitable for use in mapping high-wind and gust events, however. It is shown that the seismic channels exhibit well-defined spectral signatures under conditions of high wind, with a variance peak at frequencies of similar to 0.04 s(-1) and an amplitude that appears to scale with the magnitude of observed wind gusts.
Funding Acknowledgement: National Science Foundation [1019603]; Incorporated Research Institutions for Seismology [EAR-1261681]; National Science Foundation
Funding Text: This material is based upon work supported by the National Science Foundation (Grant 1019603) and the Incorporated Research Institutions for Seismology under their Cooperative Agreement EAR-1261681 with the National Science Foundation. The NCDC-6421 and ASOS datasets used herein were obtained from the National Climatic Data Center. The clarity of the presentation was greatly enhanced by the thoughtful comments of two anonymous reviewers.