Nashville NWS Needs Your Help!

By: Astrometeor , 3:11 AM GMT on May 04, 2014

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***Important Note***
The following has been transcribed from the Nashville NWS-WFO's page. Click here to be taken to source. The message is particularly aimed for anyone living in the southern Middle Tennessee region of the state.

Have you seen debris in your yard this week? It may be from the Lincoln County EF-3 Tornado!
We Need Your Help!
Did you see any debris in your yard this week?
It may have come from the Lincoln County Tornado!

On Monday April 28th, 2014, a severe weather outbreak across the lower Mississippi Valley and much of the southeast US resulted in multiple tornadoes spanning from the Louisiana/Mississippi border up into northern Alabama, Southern Middle Tennessee and northern Georgia. One such tornado occurred just south of the Nashville county warning area (in Huntsville's area) in Lincoln, County Tennessee which resulted in 2 fatalities.

Here is a map of the active weather period across the southeast US from April 27th - April 30th. The April 28th tornado outbreak is highlighted in red:

(fatalities are indicated by boxed numbers)



The Lincoln County EF-3 tornado was one that both the Huntsville and Nashville offices were watching very closely. While the Huntsville NWS office was busy tracking the tornado that was moving through Lincoln County, the Nashville office was preparing their warning and letting the emergency manager in Coffee County know that the city of Tullahoma was in the path of the tornado, should it continue to stay on the ground.

This is what the meteorologists at both offices were seeing in chronological order:



At 8:09 PM CDT, according to the NWS Huntsville damage survey (Found Here), the tornado touched down in extreme southern Lincoln county. Five minutes later at 8:14 PM, the radar first detected a Tornado Debris Signature (or TDS) on the KHTX radar in northern Alabama. You can see it on the right hand side of the picture as the little blue speck south of Fayetteville (see above).

The image on the left is traditional reflectivity, which tells the meteorologist about intensity of rainfall and/or hail within the storm. In classic supercells, the reflectivity structure looks much like a backwards comma. The comma head part of the storm is called the "hook echo" as indicated on the left hand side of the picture above. This is where the tornado would typically be found. With the recent upgrade to Dual-Polarization technology, the radar can see much more than before. On the right hand side, is the new Dual-Pol radar called Correlation Coefficient which can differentiate between rain, hail, or in this case, tornado debris. The lower the CC value, the more likely that it is NOT a meteorological target. In the above image, the very low CC values (indicated in blue colors among the purple), located within the hook echo, tells the meteorologist that this signature is most likely tornado debris and that a tornado is in fact on the ground at this time.



At 8:23 PM, or 14 minutes after the tornado touched down, the TDS signature (right) continues to be seen on the CC radar image. Also, the hook echo on the left shows dark red colors meaning that the objects within the hook echo are reflecting back to the radar very brightly. When the reflectivity values within the hook echo are in the reds or higher, it too indicates debris within the tornado. In fact, this signature is often called a "debris ball" since it looks like the comma head has a ball at the end of it. The CC signature is quite a bit larger than the previous scan, which means the tornado continues to intensify and becoming stronger as it moves northeast through Lincoln County.



At 8:33 PM, or 24 minutes after touchdown, the tornado begins to lift, ending its damage path in southern Moore County (again according to the NWS Huntsville damage survey). As can be seen in the reflectivity image on the left, the hook echo is not as defined as in the previous scan, indicating weakening in the circulation. The supercell is looking less like a comma and losing its overall structure. Good news for residents of Lynchburg and Tullahoma which were in the path of this storm! However, if you look at the CC image, the TDS looks even bigger and brighter than it had in the last two scans. Well, it can't be that the tornado is getting stronger and wider, because the survey concluded it had ended at this point. What could it be?

As it turns out, the debris associated with the tornado continued to be carried in the winds associated with the supercell. Although not shown here, the TDS was seen over 20,000 feet! At these heights, the wind field was over 50 knots from the southwest. So what happened here is the debris was lofted so high that it was beginning to get caught in the upper level winds and carried downstream into southern Middle Tennessee! So while on radar, it may seem like the tornado was getting bigger, it had actually dissipated and its debris was being carried by the winds to the northeast.



Now at 8:47 PM, it is becoming more clear what is happening. The supercell continues to deteriorate with the hook echo very small and moving north into southern Bedford County. The CC values on the right are not as deeply blue, although some pixels are still very blue but they are more spread out and broad than previously. The debris cloud is expanding to the northeast, which makes sense considering the winds at this height are strongly southwesterly. So while the debris cloud indicated on the CC radar image begins to expand into Coffee and Bedford counties, a phone call comes from the Coffee County EMA Allen Lendley...

"Hey there Nashville, this may sound strange but a volunteer fire fighter on the road outside of Manchester just reported that pieces of paper are falling from the sky. Do you know anything about what he is talking about?"
(*not a direct quote)

Why yes Allen, we might have an explanation for that!



Now here at 8:56 PM, 23 minutes after the tornado lifted and 47 minutes after it initially touched down in southern Lincoln County, the supercell has more or less fallen completely apart. The Nashville office has cancelled their tornado warning they issued for this storm due to it weakening and losing its velocity signature as well (not shown). However the debris cloud continues to spread out and drift to the northeast in the upper level winds. The cloud is beginning to enter southeast Warren County and approach the city of McMinnville. Preliminary reports from the McMinnville area have come in since Monday with reports of debris being found. This debris cloud would continue to drift northeast before dissappearing finally just before reaching Crossville!

The Nashville county warning area (all of Middle Tennessee excluding Franklin, Lincoln, and Moore counties) was lucky enough to avoid any tornado activity that evening. One tornado was confirmed earlier in the day in White County but for the most part, the Mid-State dodged quite a bullet on Monday night!

The NWS Nashville office has analyzed the debris signature on both KHTX and KOHX radars and have put together this subjectively analyzed map of where debris may have landed across southeastern Middle Tennessee. If you live in the area shaded yellow in the below image, you may have had some debris fall in your yard! In order for debris to be picked up and lofted this far, its most likely the debris you might find would be lightweight, like paper, envelopes, pictures, or insolation.



If you happen to discover something like this in your yard over the next week, PLEASE LET US KNOW! We are attempting to put together a map of debris fall based off your reports to correlate with the radar data so we can better understand how these TDS signatures can help us see what is happening in reality. Also, you might find something like someone's family photos that might want to be returned by the people who lost them. Hopefully we can return some of these lost items back to their owners!

If you find anything in your yard that you think is debris associated with the tornado, please submit a picture of the debris and either the GPS coordinates of where you found it, or the address information to our Facebook page, tweeting the information to our Twitter page(@NWSNashville) or emailing us at sr-ohx.spotters@noaa.gov.

We appreciate your help!

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25. WunderAlertBot (Admin)
2:45 AM GMT on May 11, 2014
Astrometeor has created a new entry.
24. Astrometeor
5:54 AM GMT on May 09, 2014
Hi WeatherWise!

I'm really used to the weather here, there's really nothing to be worried about since all you can really do is prepare for a future storm. In the event of one, you follow the standard procedure (lowest floor, interior room, or basement) and wait it out. Getting scared just seems to complicate the situation.

Besides, the biggest scare I've had was back in 2006. Had a F3 slice in between my school and my home. I was sheltering in my elementary school...that was a bad day.

Ever since that day, I'm not really scared of the storms, I just respect their power and know what to do in case of an emergency.

The Weather Service's motto is "Don't be Scared, Be Prepared!"

Hope that helps.
Member Since: July 2, 2012 Posts: 101 Comments: 10365
23. WeatherWise
12:12 PM GMT on May 07, 2014
Hi Astro! I was in TN during that storm outbreak and was quite scary and made me do some quick soul-searching. When my daughter said Mom I want you to get your essential items like meds to bring in closet with us. In case, the house is gone when we come out, I would hate for you to be uncomfortable for a long time without your meds. I put a few things in a Walmart bag realizing very little was essential - mostly everything was just stuff and could be replaced. I was really scared and upset and wondered how you learned to deal with it without being so scared all the time. I was thankful when the weather finally cleared.

I am back home in Virginia now and it is quite pretty here. The May flowers are quite lovely here!


Member Since: February 28, 2003 Posts: 44 Comments: 1522
22. BaltimoreBrian
3:45 AM GMT on May 06, 2014
This is Lupoid, one of the sled dogs on the Endurance, named for his wolfish appearance.

Member Since: August 9, 2011 Posts: 26 Comments: 8631
21. Astrometeor
3:33 AM GMT on May 06, 2014
Quoting BaltimoreBrian:
The ship Endurance was trapped in ice for 9 months before pressure crushed it. The ship was trapped in late January 1915, and held tough for 9 months (the hull was more than a yard thick, and relatively flat, so ice pressure would tend to pop it up.) However in October 1915 the ship was crushed. Wreckage was still visible in December 1915 when they finally started walking away. But it's long sunk.


You could say, it endured those 9 months.

Member Since: July 2, 2012 Posts: 101 Comments: 10365
20. BaltimoreBrian
3:20 AM GMT on May 06, 2014
The photograph was taken close to the end of a more than four-month night. Good thing there wasn't a vampire on board!
Member Since: August 9, 2011 Posts: 26 Comments: 8631
19. BaltimoreBrian
3:17 AM GMT on May 06, 2014
The ship Endurance was trapped in ice for 9 months before pressure crushed it. The ship was trapped in late January 1915, and held tough for 9 months (the hull was more than a yard thick, and relatively flat, so ice pressure would tend to pop it up.) However in October 1915 the ship was crushed. Wreckage was still visible in December 1915 when they finally started walking away. But it's long sunk.
Member Since: August 9, 2011 Posts: 26 Comments: 8631
18. Astrometeor
3:13 AM GMT on May 06, 2014
Quoting BaltimoreBrian:
The Endurance, August 27, 1915. A cool birthday Nathan?



Is that ship sitting on ice or at the bottom of the ocean? It's hard to tell...
Member Since: July 2, 2012 Posts: 101 Comments: 10365
17. BaltimoreBrian
2:40 AM GMT on May 06, 2014
The Endurance, August 27, 1915. A cool birthday Nathan?

Member Since: August 9, 2011 Posts: 26 Comments: 8631
16. Astrometeor
2:12 AM GMT on May 06, 2014
Quoting Bluestorm5:
I predicted 89 yesterday for Nashville. It got up to 88 today there :)


My weather station registered 91.8, but that thing is sited in the sunlight...meanwhile the porch thermometer measured 88.

Stop gloating. :/
Member Since: July 2, 2012 Posts: 101 Comments: 10365
15. Bluestorm5
1:49 AM GMT on May 06, 2014
I predicted 89 yesterday for Nashville. It got up to 88 today there :)
Member Since: August 1, 2011 Posts: 28 Comments: 8032
14. Astrometeor
11:32 PM GMT on May 04, 2014
Radar and velocities for the Flintville, TN tornado. Courtesy of the Huntsville, NWS.





Source
Member Since: July 2, 2012 Posts: 101 Comments: 10365
13. Astrometeor
11:29 PM GMT on May 04, 2014
Quoting sar2401:

Has this made the local media at all? Unless it has, and enough people are out there looking, they're not going to get many reports. When the Challenger went down, NASA tracked its path as being right over the coast in our county. They asked us to mount a search for any debris, and we spent about 600 man hours out on the coast looking. Many of our "beaches" are just a tangled mass of driftwood and boulders at the bottom of cliffs, so it was slow going. Our teams picked up 27 pieces of out of place looking stuff, and it turns out only one thing, an 8 inch long piece of wiring, was actually from the shuttle.


Eh, I have no idea. I don't pay attention much to the local news except for an occasional glance at the Tennessean. *Shrug* I suppose the local town newpapers or EMTs could pass out the info, but I don't live down there so I really have no clue.
Member Since: July 2, 2012 Posts: 101 Comments: 10365
12. MaxWeather
11:18 PM GMT on May 04, 2014
Quoting 9. BaltimoreBrian:

Did you find anything in your yard Nathan?


No Brian... you don't need to go that far.

Check Astro's bedroom. ;)
Member Since: April 11, 2014 Posts: 24 Comments: 1243
11. sar2401
11:03 PM GMT on May 04, 2014
Quoting Astrometeor:


No, I don't live in the area. Look at the handy map that the NWS made. You should check in with hydrus, he lives much closer to the area than I do.

Has this made the local media at all? Unless it has, and enough people are out there looking, they're not going to get many reports. When the Challenger went down, NASA tracked its path as being right over the coast in our county. They asked us to mount a search for any debris, and we spent about 600 man hours out on the coast looking. Many of our "beaches" are just a tangled mass of driftwood and boulders at the bottom of cliffs, so it was slow going. Our teams picked up 27 pieces of out of place looking stuff, and it turns out only one thing, an 8 inch long piece of wiring, was actually from the shuttle.
Member Since: October 2, 2004 Posts: 0 Comments: 16207
10. Astrometeor
9:41 PM GMT on May 04, 2014
Quoting 9. BaltimoreBrian:

Did you find anything in your yard Nathan?


No, I don't live in the area. Look at the handy map that the NWS made. You should check in with hydrus, he lives much closer to the area than I do.
Member Since: July 2, 2012 Posts: 101 Comments: 10365
9. BaltimoreBrian
7:58 PM GMT on May 04, 2014
Did you find anything in your yard Nathan?
Member Since: August 9, 2011 Posts: 26 Comments: 8631
8. Astrometeor
6:19 PM GMT on May 04, 2014
Quoting MaxWeather:
I can go to Chattanooga, I remember seeing a tornado warning for the city for quite some time.
lol ^^


I don't understand?
Member Since: July 2, 2012 Posts: 101 Comments: 10365
7. MaxWeather
3:19 PM GMT on May 04, 2014
I can go to Chattanooga, I remember seeing a tornado warning for the city for quite some time.
lol ^^
Member Since: April 11, 2014 Posts: 24 Comments: 1243
6. Bluestorm5
6:42 AM GMT on May 04, 2014
Thank you.
Member Since: August 1, 2011 Posts: 28 Comments: 8032
4. Bluestorm5
6:36 AM GMT on May 04, 2014
Quoting 2. sar2401:

It will be interesting to see what they come up with. This is certainly not the first debris cloud to have come from a tornado, but the dual-pol radar allows the NWS to see and track it much better than single-pol ever could. That have always been reports of things found many miles for a tornado but never, to my knowledge, has there been an attempt made to actually map what was in that cloud and far it went.

BTW, did you notice this sentence -

"...its most likely the debris you might find would be lightweight, like paper, envelopes, pictures, or insolation".

Unless sunlight has fallen in the yard and not insulation, Kyle's not the only one to make blog errors. Even the NWS slips up occasionally. :-)


I've been trying to get him to take it down because it's embarrassing, but he won't respect my wish.
Member Since: August 1, 2011 Posts: 28 Comments: 8032
3. Astrometeor
6:33 AM GMT on May 04, 2014
Quoting sar2401:
It will be interesting to see what they come up with. This is certainly not the first debris cloud to have come from a tornado, but the dual-pol radar allows the NWS to see and track it much better than single-pol ever could. That have always been reports of things found many miles for a tornado but never, to my knowledge, has there been an attempt made to actually map what was in that cloud and far it went.

BTW, did you notice this sentence -

"...its most likely the debris you might find would be lightweight, like paper, envelopes, pictures, or insolation".

Unless sunlight has fallen in the yard and not insulation, Kyle's not the only one to make blog errors. Even the NWS slips up occasionally. :-)


Nah, I didn't. insolation vs insulation is something my eyes tend to gloss over. Other things tend to bug me...and then someone makes the mistake of "I am not challenging you to look for errors", and...yeah.
Member Since: July 2, 2012 Posts: 101 Comments: 10365
2. sar2401
6:31 AM GMT on May 04, 2014
It will be interesting to see what they come up with. This is certainly not the first debris cloud to have come from a tornado, but the dual-pol radar allows the NWS to see and track it much better than single-pol ever could. That have always been reports of things found many miles for a tornado but never, to my knowledge, has there been an attempt made to actually map what was in that cloud and far it went.

BTW, did you notice this sentence -

"...its most likely the debris you might find would be lightweight, like paper, envelopes, pictures, or insolation".

Unless sunlight has fallen in the yard and not insulation, Kyle's not the only one to make blog errors. Even the NWS slips up occasionally. :-)
Member Since: October 2, 2004 Posts: 0 Comments: 16207

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About Astrometeor

Age: 18, b-day is 8/27. Graduate of MLK High in Nashville, TN. Will attend MU in PA. Love football, soccer, Frisbee, Scouts, Science Olympiad.

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