Small scale disturbance caused by high winds are a common driver of change and successional dynamics in northeastern forests. Forest gaps created by canopy openings allow for regeneration of flora and habitat diversity for fauna. However, changes in the frequency, extent and severity of high wind events can alter sensitive habitats, species composition and invasion by non-native plants. Climate projections indicate that high wind events may become more common across the region.^{1 2} Based on 20 years of data from the NOAA global historical climatology network daily summaries (GHCND) dataset we calculated the number of high wind days (winds exceeded 55mph (48kts) for at least 5 seconds) at 73 stations across the region. This threshold was selected based on wind speeds that typically cause forest damage as reported in the Beaufort scale, the Enhanced Fujita Scale and the Saffir-Simpson Hurricane scale.

Analysis

• Frequency
• Extent
• Severity
• Location

Disturbance Trend Summary

Long-term trends across the region indicate that the average number of high wind events at any given station is stable.

Interestingly, the both the average maximum wind speed and the number of extreme high wind events (>95 percentile) has decreased significantly, indicating that while high wind events are becoming more widespread and frequent, extreme wind events are not.

Highlights

• 2005 recorded the highest number of extreme high wind events, likely due to Hurricane Katrina. This serves as a reminder, that even in inland parts of the region, hurricanes can be a widespread driver of disturbance. Note that Hurricane Sandy (2012) and Tropical Storm Irene (2011) did not contribute high wind events like Hurricane Katrina, as they were primarily rain events (see Flood).
• 2013 had several storms that brought damaging wind to the region including, winter storm Nemo, Tropical Storm Andreas and an early season blizzard. Similarly, Nor’easters in 2010 brought high winds and heavy rain across the region. This highlights that hurricanes are not the only driver of high wind events, with more localized, lower level storms also impacting northeastern forests.
• Temporal patterns in frequency and extent indicate that high wind events are becoming more widespread across the region. However, a decrease in average wind speed indicates that smaller, localized events are driving this pattern.