Wednesday, October 7, 2015

100 m.p.h-plus winds in derecho?

Damage evidence suggests 100 m.p.h. gusts.

100 m.p.h-plus winds in derecho?


In an update posted today, the Storm Prediction Center noted that incredible derecho event at the end of June was by no means the most powerful or longest-lasting on record, but it did establish a few precedents.

For one thing, the storm cener said, this was "arguably the first derecho to capture widespread media attention."

It ripped into population centers along an ever-widening cone from Chicago to Atlantic City to Tidewater, Va.

Secondly, it set smashed June and July wind-gust standards are several observation sites.

It may be impossible to figure out, however, precisely how strong the winds became in places without official observations.

Jim Eberwine, retired from the National Weather Service, had an opportunity to view the damage firsthand during the early-morning hours of June 30 in his role as emergency chief in beautiful Absecon.

He said that while the highest observed gust in Absecon and Atlantic City was 74 m.p.h., and 81 in Tuckerton, he concluded "that winds easily gusted over 100 m.p.h., judging by the number of trees" and "the type of trees snapped or uprooted."

For his estimates, Eberwine was relying on a method pioneered by the late Theodore Fujita to determine wind speeds in tornadoes.

No wind instrument, assuming one would be in the path of a tornado, would survive powerful tornadic winds.

Fujita, using thousands of photographs, developed a system for inferring wind speeds based on damages. That's why the tornado scale, first developed in 1971, bears his name.

The scale has been modified in recent years, and now is known as the Enhanced Fujita scale.

Eberwine noted that the Fujita method can be applied to straight line winds -- such as those in a derecho -- as well as winds that travel in violent circles.

A footnote: As we mentioned Gary Szatkowski, the boss at the National Weahter Service in Mount Holly, posted a post-derecho report that talks about the warnings issue.

To get to the derecho part, skip to Page 6.



Inquirer Weather Columnist
We encourage respectful comments but reserve the right to delete anything that doesn't contribute to an engaging dialogue.
Help us moderate this thread by flagging comments that violate our guidelines.

Comment policy: comments are intended to be civil, friendly conversations. Please treat other participants with respect and in a way that you would want to be treated. You are responsible for what you say. And please, stay on topic. If you see an objectionable post, please report it to us using the "Report Abuse" option.

Please note that comments are monitored by staff. We reserve the right at all times to remove any information or materials that are unlawful, threatening, abusive, libelous, defamatory, obscene, vulgar, pornographic, profane, indecent or otherwise objectionable. Personal attacks, especially on other participants, are not permitted. We reserve the right to permanently block any user who violates these terms and conditions.

Additionally comments that are long, have multiple paragraph breaks, include code, or include hyperlinks may not be posted.

Read 0 comments
comments powered by Disqus
About this blog

Everyone talks about the weather, and here we write about it.

When we’re around and conditions warrant, we’ll keep you updated about what’s coming, but we will do our best always to discuss weather and climate developments in context and remind you that nothing in the atmosphere happens in a vacuum.

Tony Wood has been writing about the atmosphere for The Inquirer for 26 years.

Reach Tony at

Tony Wood Inquirer Weather Columnist
Also on
letter icon Newsletter