High winds and resulting tree windfall are a primary source of disturbance in northeastern forests. Forest gaps created by openings in the canopy can allow for regeneration of flora and habitat diversity for fauna. However, severe or catastrophic wind damge can damage sensitive habitats that have slower regeneration timelines and allow for over competition of early successional and invasive generalist species. As climate changes in the region, high winds are expected to increase in severity, extent and frequency, which could have negative impacts on the region's forests. Based on 20 years of data from the NOAA global historical climatology network daily summaries (GHCND) dataset fastest 5-second wind speed we calculated a threshold of 55mph (48kts) for high wind events based on a comparison of wind speeds that cause forest damage from 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.