Skip to comments.Washington DC’s derecho – not something new ( Little-Known Giant Windstorms Hits DC)
Posted on 07/03/2012 9:19:36 PM PDT by Ernest_at_the_Beach
Derechoes have been in the news in Washington as of late. No, thats not some new breed of super bureaucrat, but it is something from a supercell sized thunderstorm that crossed several states during its lifetime. You may have seen this NOAA image already on a few news websites:
Thats a time lapse radar image capture as the storm progressed from near Chicago to Chesapeake Bay.
Theyve been known over a century, and around far longer than that. Wikipedia says that Derecho comes from the Spanish word for straight.The word was first used in the American Meteorological Journal in 1888 by Gustavus Detlef Hinrichs in a paper describing the phenomenon and based on a significant derecho event that crossed Iowa on 31 July 1877.
They were further refined with the advent of weather radar. Derechos are typically bow or spearhead-shaped on weather radar, and hence they are also called a bow echo or spearhead radar echo. Heres a WSR-57 radar image from Cleveland, Ohio in 1969:
July 4, 1969 The Ohio Fireworks Derecho spanning MI, OH, PA, WV
They are fairly common meteorological events, occurring from May to August, peaking in frequency during the latter part of June into July. According to NOAAs Storm Prediction Center, the Washington DC area gets a derecho about once every four years:
Heres a few of the past logged by the Storm Prediction Center.
Here, thanks to modern radar technology and people who are interested enough to track storms on radar from start to finish, we have this life cycle of the derecho:
Timelapse of closest NEXRAD base reflectivity of the 29 June 2012 derecho. The timelapse moves from Davenport, Iowa to Richmond, Virginia over 14 hours.
Heres a cross section, showing how the mesoscale thunderstorm dynamics make that bow echo. Image courtesy of the NOAA Storm Prediction Center page about derechoes:
What is troubling about this being linked to global warming is the Washinton Post Capital Weather Gangs story by Jason Samenow, which ends with this gem:
As the intensity of the heat wave, without reservation, was a key factor in the destructiveness of this derecho event it raises the question about the possible role of manmade climate warming (from elevated greenhouse concentrations). Its a complicated, controversial question, but one that scientists will surely grapple with in case studies of this rare, extraordinary event.
Yet Samenow cites the same sources from the Storm Prediction Center page that I do, showing the exact same image above (after editing out the number 3). Yet somehow, he managed to conveniently ignore the historical context and the climatological frequency of derechoes on that page.
Hes gets the coveted WUWT Double BS award for his sloppy journalism.
Joe DAleo has more on the derecho event here at ICECAP.
UPDATE: I made an error. I got two different posts mixed up related to the heatwave, conflating the quote discussing the heat wave by Doug Kammerer (with thunderstorm radar loop in background video by Karins on the CP post) . Ive removed the citation (and video) related to NBC Bill Karins quoted on Climate Progress. My sincere apologies for the error. My only defense is that I dont listen to audio much anymore due to my hearing issues. Thankfully, Ive got a big group of people that will let me know immediately that Ive made an error, and thus Ive heeded their advice and fixed the error within minutes of this posting. Thank you. Anthony
Thanks - nice to get some good info on what hit us Friday night.
Not a weather person, but that was very interesting, and easy to understand. Thanks
I’m a good six hours south of DC and even here we had wild wind. It came on with no warning at all, no thunder or lightning, like a shockwave or something. Ten to fifteen minutes of very high wind seemingly out of nowhere, trees thrashing like a Category 1 hurricane, leaves and branches flying, numerous power outages but nothing on the scale of points north.
Thanks for posting this. Most interesting. First time I ever heard the word was last year on the Weather Channel. I don’t recall them using the term before then, but, once they did, it seemed like they had a new play toy (word) and it was repeated many times.
Likewise, TWC is doing the same with the term “haboob” which means dust storm or a big dust storm. Once again the on camera folks seemed infatuated with the word so it was used constantly. Frankly, bow echo and dust storm are much easier to understand and don’t make the meteorologist sound like arrogant twits.
I’m 90 miles west and was on a Harley, 10 miles from home when the winds hit.
That was a wild ride.
[and apparently I don’t weigh enough to myself firmly planted in the seat]
My only real concern was all the old, dead, feeble trees lining the road and overhanging the power lines.
I once read the diary of an Englishman during the war of 1812 who was trying to reach Detroit. He started west through North Carolina and told about the problems of trying to cross what was known then as the downed timbers.
He related in some areas it was several miles wide and hundreds of miles long where not a tree was left standing. This was result of a storm which had struck years before killing all the Indians and settlers in it’s path.
I’d have hated to have been in a mountain gap in any sort of vehicle when that hit, let alone on a motorcycle, lol. I hope you parked and rode it out stationary, or was there no place to stop?
Well, ironically, “mountain gaps” are the *only* way I can get home, no matter where I go...;D
So, I kept going.
There are tons of places I could’ve stopped but I wanted to go home.
The only time I ever stopped for “weather” was one frog-drowner sudden downpour where the water was so deep on the road we were hydroplaning.
After we got about 4 miles from the house, hubby pitched a fit because I suddenly stopped and blocked his way.
A transformer had blown and a live wire was whipping across the road.
I sat there until it was on the other side of the road and the gunned it before it whipped back into the west bound lane.
[yes, hubby followed]
He had *no* clue what had happened until we were in the shop drying off and I told him.
[I’ve made a fair hillbilly out of him but I still had a 30 year head start]
The Boundary Waters - Canadian Derecho [July 4, 1999]
That is fascinating. And the graphic reminds me a lot of the timelapse graphics being used as examples of weather modification technology explanations made by the semifamous Dutchsinse (www.dutchsinse.com) Technology imitating nature.
So are haboob dust storms in New Mexico generated by the same type of phenomenon ? They seem to develop from winds that are just pushed out in front of a thunderstorm cell.
Thanks for posting this information. First time I have ever heard of this kind of storm.
My sister has a home in the DC area, and also (our parent’s home) in northern Minnesota. BOTH were hit, with trees down on the house, by derechos this weekend.
It is a good book, but not quite accurate. The story took place on Lake-of-the-Woods, which was not hit by the Boundary Waters Derecho. Look at the map linked in the Anthony Watts blog.
Derecho is a Spanish word meaning “right” or “upright.” As such, its plural is “derechos.”
If it hit DC, it was well-deserved derechos for borrachos as far as I’m concerned.
Pronunciation? Is it Der’ eh ko? or is it Dar ee’ ko? Or, does it ens in cho? (as in choke)
It ends in “cho” like macho.
I looked it up on the Web, and they say that it is day-ray’-cho.
Thanks. See #23.
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