| Abstrakt: |
Prompted by recent findings of a common trend toward lesser near-surface winds (NSW), or stilling, time series of cool season NSW variables for 20 stations in the central Appalachian Mountains of the eastern United States were examined for trends during the period 1995–2022. While not universal across the station array, results generally indicate an increase in the frequency of calm conditions, a decrease in mean wind velocity, and a decrease in the frequency of high-wind days. Contrasting this was a general increase in high-wind gust days. The evidence for stilling was supported by an increase in the frequency of days with a 12-hour pressure change of zero and an apparent strengthening and northwestward expansion of the subtropical ridge over the region. Supporting the increase in high-wind gust days was an increase in the frequency of days with a large 3-hour pressure change, and lesser geopotential heights in the lower atmosphere northwest of the region, which contrasts the expanding subtropical ridge and together presents the potential for periodic placement of stronger dynamics across the region. [ABSTRACT FROM AUTHOR] |
