2009.08.18
So was this a tornado?
From an overlook just off the Blue Ridge Parkway near Explore Park east of Vinton, I watched a storm go across the Roanoke Valley this afternoon, and shot several frames (click here and here for examples) that show a funnel-like extension reaching a ridgetop. It has wider base near the surface similar to a debris cloud that could be spun up by a funnel. So was it a tornado?
NO! it was not in any way, shape or form a tornado, but rather scud clouds being pushed along by the outflow boundary of a thunderstorm. There was no rotation, and what's more, the wider piece along the ridgetop actually formed independently before the clouds above connected to it. It was one of those foggy kind of low clouds that form in the mountains from evaporation of rain, and eventually the lowering at the front of the outflow connected with it as they both blew along in front of the storm.
It was a picturesque storm that produced some photogenic scenes as it brought heavy rain and briefly gusty winds to the valley this afternoon. But it wasn't a severe storm, and it certainly didn't spawn any tornadoes.
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Kevin, based on my SkyWarn spotter training, that would qualify as a SLC, or Scary-Looking Cloud. They trained us to watch for rotation within the clouds, because these sorts of things happen pretty frequently and a lot of folks will call them in mistaking them for a possible funnel or tornado. I saw something like that in the storm over Shawsville yesterday. I have seen rotation in storms before, after spending a summer in Missouri. It's not something I've seen very often in Virginia.
Comment by Other John — August 18, 2009 @ 9:22 pm
SCUD Saw alot of that today littering the sky near the mountains . i saw that same formation in stewartsville today . no rotation
Dean
Comment by Dean D Davison — August 18, 2009 @ 9:44 pm
Other John: I will probably submit these photos to the NWS for use in their "SLC" collection.
Dean: It was headed toward Stewartsville when I shot this.
Would have been neat to be on that ridgeline and see this wall of fog being pushed through the trees by the thunderstorm outflow.
Comment by Kevin Myatt — August 18, 2009 @ 10:41 pm
If you want another example of a "non-tornado" here is a photo I took in Colorado in 2008. It looks like a wedge tornado, even a hint of a debris cloud, but in fact it's just a big rain shaft.
http://blogs.roanoke.com/rtblogs/weatherjournal/files/2009/08/colorainwedge.jpg
Comment by Kevin Myatt — August 18, 2009 @ 10:46 pm
Kevin et al: Is this extreme humidity partially because some of the remnants of Claudette have made their way into our area? I used the word "extreme" intentionally. I have lived in the Roanoke area since October 1997, and Lynchburg's dew point at 10 PM tonight was one of the very highest I have ever heard of since I moved here. Roanoke's dew point was an awful 72, but L'burg's was a brutal 76. I once saw a dew point of 80 when I lived in Alexandria, VA, just a few miles south of National Airport and Washington, DC. Other John, was it you who said that the highest temp you have seen in the Wytheville area since you moved there was 94 degrees in September several years ago? One more item. Hurricane Bill has just exploded to top sustained winds of 125, a decent Category 3. The island of Bermuda could be in a lot of trouble.
Comment by Doug Griggs — August 18, 2009 @ 10:53 pm
In response to the comments yesterday by Brandon and Kevin concerning the projected path of Bill, I strongly agree with you, KM, based on observing the movements of Atlantic trop storms and hurricanes over the last 20+ years. You may end up being right, Brandon, that Bill will make landfall on the coast in the mid-Atlantic, but I would be willing to bet quite a bit that it misses the coast from Connecticut southward. It might hit SE Mass or Nantucket, but I bet that it even stays east of there. I have noticed that on several occasions in previous years the projected path keeps edging eastward. If that happens, Bermuda would be in Bill's "gunsights," but it would miss the entire US coastline, possibly grazing Nova Scotia.
Comment by Doug Griggs — August 18, 2009 @ 11:00 pm
Kevin, that would definitely be a good submission for them to use as it looks very convincing and would likely fool many folks not familiar with what to look for. I've gotten very lucky through the years of not being caught in any tornadoes, despite spending time in the midwest and living at the oceanfront where hurricanes frequently interacted or made landfalls nearby. I've been through several warnings, but never so much as seen a funnel. The scariest weather I have been in was a microburst that hit the area near Chesapeake General Hospital back in the early 90's. The big outbreak of August 1993 also missed a few miles to my south with 2 different tornadoes, an F1 and F2.
Comment by Other John — August 19, 2009 @ 12:46 am
Doug: We are drawing in more tropical air, only partly related to Claudette. So Wednesday should be a soupy day with showers and storms again, though those high dew points will probably mix out into the 60s with daytime heating.
Comment by Kevin Myatt — August 19, 2009 @ 12:54 am
As for the tropics.. Bill looks like it's going to wreak havoc with the fishies.
Ana... well, I don't know. I can see some circulation on the water vapor loop in the Gulf of Mexico but it looks like it's heading due west and that would put it over more land (the Yucatan).
We'll see. What do you think, Kevin?
Comment by Brandon R — August 19, 2009 @ 7:52 am
Doug:
It was I that said the highest temperature I have measured in Wytheville had been in September. That was 93.9 on Sept 13,1999.............but alas, I see I made a mistake. We broke that with exactly 94.6 on BOTH August 16 and 24 in 2007..........remember that Ausgust, yuck, the hottest month ever in Roanoke and probably all of SW VA.
These temperature extremes just cover 1996-present, since I live in Nebraska prior to that.
Comment by Rick — August 19, 2009 @ 8:08 am
Doug, I think that was probably Rick, since I don't live in Wytheville. Though, the hottest I think I've seen in my neck of the woods since moving here in 2000 has been around that 94-96 range. I've been through some brutal 110 degree heat waves in Michigan before (thankfully somewhat drier than here), but also a few 100+ days in Virginia Beach and Raleigh (w/o A/C...yuck!) with a ton of humidity which made it downright unbearable.
Comment by Other John — August 19, 2009 @ 8:16 am
Ana looks kaput to me, and Bill curving away from the U.S. If Bill has any direct impact, Cape Cod or Maine would be most likely ... after crossing colder waters and encountering shear to weaken it.
Comment by Kevin Myatt — August 19, 2009 @ 10:41 am
One of the more recent maps seemed to show Bill making a landfall in Nova Scotia as a still major hurricane. For whatever reason, I've always liked that area of Canada, but the prospect of continually dealing with hurricanes and potent winter storms would be a bit much.
Comment by Other John — August 19, 2009 @ 11:07 am