04/02/2006 DISC: IA/IL/MO/AR/TN

I just wanted to comment on the SPC's forcast for today. They got it pretty much right, but I noticed that there were also quite a few tornadoes outside of the moderate risk area (most notably the long-track one in Arkansas). There were also quite a few high wind reports way east of the moderate area. I noticed that they moved the moderate risk area east quite a bit at the end of the day.

Having no in-depth meterological training, I won't criticize the SPC at all. They did a great job on March 12th, 2006. But I think they were a little off on the moderate risk area they were pushing today. Not only that, but with at least 11 dead and 60+ preliminary tornado reports I think today was absolutely a high risk day. I really have no idea why they didn't issue a high risk today.

So, up for discussion, should the moderate risk have been expanded to areas further south and east earlier in the day and why did the SPC not go with a high risk?
 
Honestly I think SPC's decision to hold off on the high risk had a lot to do with Saturday's outflow-dominated garbagefest. Evolution of convection Sunday was highly dependent on the same mesoscale/boundary layer processes that Saturday's was. Sometimes you get it, and sometimes you don't.

The vast majority of the convection across the initial moderate risk area was linear, yet still managed to produce quite a few tornadoes in addition to widespread damaging winds and hail. Despite the possibility of more discrete convection to the south (in southern MO/AR/western TN and KY) that area was left out of the moderate risk early on. I would presume that had something to do with concerns over surface winds not being ideal for intense tornadoes. Obviously something changed or was being overlooked. It might be interesting to compare the short-term low-level wind field model forecasts from immediately before the event with what was actually observed.
 
These LSR's are particularly sad. Many reports include damage swaths more then 1/2 mile wide. This tornado had enormous G2G Shear with it that, at times, was spread out over a very large area. Our thoughts and prayers have to go out to the victims and their families.

0755 PM TORNADO NEWBERN 36.12N 89.27W
04/02/2006 DYER TN AMATEUR RADIO

*** 11 FATAL *** IN THE NAVOO COMMUINITY ALONG HWY 2
HOUSES DESTROYED. POWER KNOCKED OUT. FATALITIES ON BIFFLE
ROAD NEAR JIMMY DEAN PLANT IN NEWBERN. ADDITIONAL
FATALITIES OCCURRED IN THE BOGOTA AREA.
----------------------------------------------------------------------------------------
0843 PM TORNADO 1 W BRADFORD 36.07N 88.84W
04/02/2006 GIBSON TN LAW ENFORCEMENT

*** 8 FATAL, 50 INJ *** FATALITIES OCCURRED IN THE
RUTHERFORD/BRADFORD AREA.
 
Also, just keep in mind that the daybreak has just broken across this area and I am sure we will be getting some chilling photographs before this is all over with. Could you guys please post news images here if you find them of damage.
 
I just wanted to comment on the SPC's forcast for today. They got it pretty much right, but I noticed that there were also quite a few tornadoes outside of the moderate risk area (most notably the long-track one in Arkansas). There were also quite a few high wind reports way east of the moderate area. I noticed that they moved the moderate risk area east quite a bit at the end of the day.

Having no in-depth meterological training, I won't criticize the SPC at all. They did a great job on March 12th, 2006. But I think they were a little off on the moderate risk area they were pushing today. Not only that, but with at least 11 dead and 60+ preliminary tornado reports I think today was absolutely a high risk day. I really have no idea why they didn't issue a high risk today.

So, up for discussion, should the moderate risk have been expanded to areas further south and east earlier in the day and why did the SPC not go with a high risk?
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Bryce,

I've worked at SPC long enough to not get too upset when folks criticize our forecasts. It seems everyone is an expert *after* the event :p

Anyway, I worked day shift yesterday, so I can comment on that part of the episode. A squall line swept across the majority of the MDT risk area during the early morning hours, leaving the 60+ dewpoints to the S of MO/IL. Still, steep lapse rates were present and the main shortwave trough was expected to pivot over the recovering warm sector in MO during the afternoon, when storm development was anticipated. Low-level shear profiles were modest in the open warm sector through the day (0-1 km SRH AOB 200 m2/s2), while the somewhat stronger shear was located along the warm front where the low levels had yet to destabilize. The MO/IA/IL part of this event was a race between destabilization along the warm front and the transition from a more discrete to linear convective mode.

Farther S, the question was convective initiation. The influence of the mid level trough appeared to extend as far S as nrn AR. There was not much of a low-level focus for initiation there, but afternoon temperatures got warm enough to reduce convective inhibition and allow things like convective rolls and terrain to intitiate isolated storms. The nrn AR environment consisted of strong deep layer shear and large CAPE (near 3000 J/kg for ML parcel), but similar low-level shear to MO and rather large T-Td spreads. Our guess was that the initial storms would mainly be a threat to produce very large hail, which they did. By early-mid afternoon, we noticed that the clouds and early precip across ern AR/wrn TN/wrn KY had held temperatures down, but winds were still backed to more southerly and dewpoints had remained in the mid 60s. We weren't sure how long the backed flow area would hang on after the precip moved away by mid afternoon and the clouds began to erode, but I thought enough of it to go TOR watch and mention the possibility of an increase in the tornado threat toward nern AR.

In retrospect, that favorable area did hold on and shear even improved during the evening, when the tornado threat appeared to peak. In the perfect world I would have issued PDS TOR before any cumulus clouds had formed, but there was just too much uncertainty. The environment was modified on the mesoscale by the early clouds/rain, and that is always going to present a problem for longer range outlooks. I also worked 3 May 99 back in the day, and I promise that *nobody* on this list would have believed a perfect forecast from that morning relying on subtle confluence boundaries, HCRs, a cirrus hole (none of which were resolved until late morning or afternoon), and a poorly forecast speed max!

By the way, the long track supercell cut across the MO bootheel, which was in the extreme srn part of the MDT risk. Why is this considered to be a bad forecast?
 
This day warranted a MDT risk until the long track supercells got going (which were under a conditional probability at the time). I was partly expecting a high risk on the 0100 UTC (there was a hatched 15% tornado probability on that one, an upgrade from the hatched 10%), but I didn't know the specifics of what was going on. The environment in TN seemed to get more favorable after the 0100 UTC outlook for long-track tornadic supercells.

The watches were issued in a timely manner and were generally well placed. This event should have only been a MDT if we take out the supercells in AR, MO, TN (the SLGT seemed warranted with all the factors up in the air). The SPC did a good job overall yesterday, with maybe the possible exception being the 0100 UTC outlook. But then again, I didn't know all of the factors there.
 
These LSR's are particularly sad. Many reports include damage swaths more then 1/2 mile wide. This tornado had enormous G2G Shear with it that, at times, was spread out over a very large area. Our thoughts and prayers have to go out to the victims and their families.

0755 PM TORNADO NEWBERN 36.12N 89.27W
04/02/2006 DYER TN AMATEUR RADIO

*** 11 FATAL *** IN THE NAVOO COMMUINITY ALONG HWY 2
HOUSES DESTROYED. POWER KNOCKED OUT. FATALITIES ON BIFFLE
ROAD NEAR JIMMY DEAN PLANT IN NEWBERN. ADDITIONAL
FATALITIES OCCURRED IN THE BOGOTA AREA.
----------------------------------------------------------------------------------------
0843 PM TORNADO 1 W BRADFORD 36.07N 88.84W
04/02/2006 GIBSON TN LAW ENFORCEMENT

*** 8 FATAL, 50 INJ *** FATALITIES OCCURRED IN THE
RUTHERFORD/BRADFORD AREA.

[/b]
I just learned a few minutes ago that the man who was killed in the clothing store in Fairview Heights, IL was the husband of someone with whom I worked for a number of years. Things like this make us realize the terrible human impact of these storms that so fascinate us.

Much less significant, the effects of this storm have been felt over an unusually wide area. We have been in the dark for 18 hours now at my house, and over 100,000 are still without power just in Missouri and Illinois. Because of the widespread straight-line winds, the effect on the power system has been unusually widespread, making it hard to bring in crews from outside because so many areas have been affected. That, of course, is trivial compared to the loss of human life, and the misery that has caused to the loved ones of those who have perished.
 
739020_vf.jpg


WHOA....check out the video of this large wedge on the ground that went through Caruthersville, MO.

http://www.kfvs12.com/
 
WHOA....check out the video of this large wedge on the ground that went through Caruthersville, MO.

http://www.kfvs12.com/
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:eek: That video is amazing! The supercell structure associated with these tornadoes was tremendous! Absolutely classic! I saw some images from other tornadoes that occurred in Tennessee, and they also had similar structure. Yesterday's supercell structure reminds me somewhat of the supercells of April 26, 1991 in that the cloud bases weren't particularly low and there wasn't a whole lot of scud underneath the cloud base. The tornadoes also seemed to have a very laminar appearance (with the exception of the wedge), which made them particularly photogenic.

As far as damage is concerned, CNN reports a fire department head (in Dyer Co., TN) as saying "There's nothing left but a foundation on some houses." It'll be interesting to see what the damage assessment reveals...it is quite probable that this particular tornado was at least an F4 (barring "sliders"). We shall see...

Gabe
 
739020_vf.jpg


WHOA....check out the video of this large wedge on the ground that went through Caruthersville, MO.

http://www.kfvs12.com/
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That is an amazing tornado.

Notice something I believe is of extreme interest in the last part of the video, there is what assumes to be a horizontal tube forming out of the main vortex stretching very near what appears to be a satellite tornado and its dust whirl. (2:31). What incredibly complex atmospheric conditions were going on at that time! This video also reminds me of a particular tornado Bobby Prentice caught I believe on April 26, 1991 I believe in was it Red Rock, OK? Same horizontal tube on the left side of the vortex but not so near a satellite tornado! Amazing!

In relation and keeping the conversation on topic, I am quite saddened to hear of the numerous fatalities from this system. I was not anticipating this degree of an outbreak, though I knew a significant episode was likely. Kudos and cheers to the SPC for doing the best they could with all the tools they had at their disposal. It was a tough day and they worked their tail ends off on it, so Rich, thanks for commenting and great job to ya.
 
Not only that, but with at least 11 dead and 60+ preliminary tornado reports I think today was absolutely a high risk day. I really have no idea why they didn't issue a high risk today.
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Last number I heard was 23 dead and they may not be through counting yet. I'll let the NWS guys defend themselves here, but it seems to me that whether the area was hatched as a moderate risk or high risk is far less relevant than whether or not the watches and warnings were going up when they needed to be. People on the ground pay no attention to the SPC's convection forecast products. Neither do media outlets. They do announce (and people hopefully pay attention) to watches and warnings. If the watches and warnings are being issued in a timely manner, then loss of life becomes a combination of who is paying attention and chance (population density in the area the tornado decides to track).

Personally, a moderate risk gets my attention. It doesn't have to be "high" for me to think that something significant could happen. But my most people probably aren't getting in the basement unless the sirens go off. And that should have nothing to do with whether the day was listed "high risk" or not.

Darren Addy
Kearney, NE
 
Rich
Thanks for commenting on this. Outlooks aside (the general public does not care about outlooks) the watches for the most part were issued in a timely manner by the SPC yesterday with one exception. There were numerous svr and several torn warnings in TN around 3pm yesterday, long before a watch was ever issued. I was just curious if you had any input on why it took so long to get the blue box up for that area of the country yesterday? When you issue a watch, do you just look at the weather to see if it is favorable for svr or do you take into account that storms are already ongoing and severe?
Thanks for your input and hard work.
Gary
 
It's also important to remember the spatial and temporal scales that differentiate convective outlooks, watches, and warnings. Outlooks are not intended to be drawn for individual storms, and neither really are watches (though there have been some very small watches that seem to have been issued based upon propagation of small storm clusters and a supercell pair). If there are only a couple of supercells, I can't imagine coverage would be significant enough to warrant a High risk. Reference back to Probability to Categorical Outlook Conversion for the probabilities needed for a high risk.

The supercells were in watch boxes, and were covered under warnings. Yes, there have been smaller enhanced categorical risks (I've seen small high risks), but the storms were already covered in a watch and were warned. Hindsight is always 20/20, and it's good to go back and do a post-analysis, but we've also seen the opposite case this year (PDS watches, high-end MDT risks, only to have trouble squeezing out more than 4-5 tornadoes).
 
Notice something I believe is of extreme interest in the last part of the video, there is what assumes to be a horizontal tube forming out of the main vortex stretching very near what appears to be a satellite tornado and its dust whirl. (2:31). What incredibly complex atmospheric conditions were going on at that time! This video also reminds me of a particular tornado Bobby Prentice caught I believe on April 26, 1991 I believe in was it Red Rock, OK? Same horizontal tube on the left side of the vortex but not so near a satellite tornado! Amazing!
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Yes, it was the Red Rock tornado. Mr. Prentice was saying "Look at the TUBE, Gene!", obviously to a chase partner. At times, that whirl in the Caruthersville video reminded me of multiple pics/video captures of the killer 1979 Wichita Falls tornado...I think they were both around the same size. Not saying one should flee from a tornado, but I've been to C'ville...nice town, southernmost county seat in Missouri, borders the Mississippi River but without a bridge. NOWHERE TO RUN in any direction east/NE/SE for those who couldn't get below ground level, unlike in the Wichita Falls whirl where there were several exit routes. (Though many lost their lives on those same routes.)

One thing about weather conditions...that Caruthersville storm from other KFVS-TV reports seemed to move almost straight east. I haven't seen sequential radar grabs but I may have seen the storms which either became or came right after the C'ville supercell. Our house is in Bentonville, AR, where the tor of three weeks ago went right over us. The skies above us were almost cloudless but around 1:00 pm yesterday cooking lunch I saw what almost looked like "feeder bands" of small eastward-moving cumulus to my north, right across the Arkansas/Missouri border. At around 4:00pm, when my son was waiting for a ride with his friend to an indoor pool we looked off to the east and I saw the back end of a line of overshooting cloud tops which looked eerily like shots (Brian?) Ensminger of KFSM-TV took of the Twin Oaks (OK)/Bentonville tornadic supercell as it sped east away from him...these supercells appeared to be either in Carroll County (Berryville/Eureka Springs) or farther east in Boone County (Harrison) in Arkansas. Horrifying to see that these storms were far worse. (I think I saw video of a pickup truck atop the roof of a structure in Tennessee...with the stripped-to-the-foundations damage I wouldn't be surprised if we see some F4 ratings, just like the 1979 Wichita Falls storm was). :(
 
Based on an aerial survey of the Dyer Co. tornado by WCMTV (based in Memphis), I can see only evidence of high-end F3 damage. Of course, they may not have surveyed the entire path length, so there might be isolated locations of violent tornado damage.

Still no PNS from Memphis...I would expect one soon, though.

Gabe
 
<div class='quotetop'>QUOTE("PAH PNS")</div>
PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE PADUCAH KY
200 PM CDT MON APR 3 2006

...WIDESPREAD THUNDERSTORM WIND DAMAGE REPORTED ACROSS PORTIONS OF
FAR SOUTHWEST INDIANA AND WESTERN KENTUCKY...

EACH COUNTY EMERGENCY MANAGER...ALONG WITH A NATIONAL WEATHER
SERVICE DAMAGE ASSESSMENT TEAM MEMBER...HAD DETERMINED THAT ALL OF
THE DAMAGE WAS DUE TO MICROBURST WINDS ASSOCIATED WITH THE
THUNDERSTORMS. WINDS ACROSS SOUTHWEST INDIANA WERE ESTIMATED TO BE
BETWEEN 60 TO 70 MPH...WHILE WINDS ACROSS PORTIONS OF DAVIESS COUNTY
KENTUCKY WERE ESTIMATED TO BE BETWEEN 80 TO 90 MPH. COUNTY
EMERGENCY MANAGERS STATED THAT THERE WERE NO INDICATIONS OF A
TORNADO.
[/b]
--> http://www.srh.noaa.gov/printable.php?pil=...=20060403191156

I only post that because there were a few tornado reports in that KPAH CWA. I am interested in seeing something out of the Memphis NWSFO.

In addition, the St. Louis NWSFO performed a very quick damage survey from a tornado in their CWA. Props for their rapid PNS release, as they had it about about 4am, less than 12 hours after the tornado occurred.
<div class='quotetop'>QUOTE("LSX PNS")</div>
NATIONAL WEATHER SERVICE ST LOUIS MO
403 AM CDT MON APR 3 2006

...PRELIMINARY DAMAGE SURVEY FOR APRIL 2 2006 ST. CLAIR COUNTY
ILLINOIS...

PERSONNEL FROM THE NATIONAL WEATHER SERVICE OFFICE IN ST. LOUIS
CONDUCTED A PRELIMINARY SURVEY OF THE DAMAGE THAT OCCURRED OVER
NORTHERN ST. CLAIR COUNTY SUNDAY EVENING, APRIL 2ND. THE DAMAGE
WAS PRODUCED BY A SHORT-LIVED TORNADO.
...
TOTAL LENGTH...7-8 MILES
WIDTH...80-90 YARDS
DAMAGE INTENSITY WAS RATED AT F1
[/b]
--> http://www.srh.noaa.gov/printable.php?pil=...=20060403090302
 
Strike my previous comments, damage looks extraordinarily severe based on viewing further video from WCM-TV. Click on "Dyer County tornado damage" in the following link, and you'll see what I mean.
Video of Aerial Survey
There appears to be several locations that took at least F4 damage (foundations wiped, only tree stumps left, etc.). Should be *very* interesting to see what rating this tornado achieves.

Gabe
 
Strike my previous comments, damage looks extraordinarily severe based on viewing further video from WCM-TV. Click on "Dyer County tornado damage" in the following link, and you'll see what I mean.
Video of Aerial Survey
There appears to be several locations that took at least F4 damage (foundations wiped, only tree stumps left, etc.). Should be *very* interesting to see what rating this tornado achieves.

Gabe [/b]

With the Dyer Count Tornado Damage link, I concur that it looks F3 to low-end F4. Usually, with the most intense tornadoes (above mid-range F4), you don't often see a whole of debris about, presumably because much of it is centrifuged away. OF course, any damage assessing we do is amatuer, since there's a lot more to it. But from a prelim point, I concur. The damage around 1:10 is interesting.

The second link that page ("Damage summary" or sometihng like that), there is an interesting part around 0:34. I'm not sure if that was a small house or what, but you can see that most of the debris has been carried away from the site. There do appear to be a few trees standing, and that truck being where it is makes me wonder if the winds were really too strong. Overall, I think the video makes me think Manchester, which was an F4.

EDIT: I should note the vehicle near the damage at 0:34 may belong to those people who are standing near the used-to-be-structure, and it's possible that the vehicle was not in the tornado. If it was in the tornado, then, from the fact that it doesn't look like it rolled me and the fact that it's up on its wheels (as vehicles should be LOL), makes me wonder if F4-level winds really were required to do the damage to whatever structure was there.
 
Hmmm - gotta wonder if we just had another "tri-state" tornado?
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I certainly would concur, Greg as it started in Arkansas, cut across the Missouri bootheel and went well into Tennessee. Crossed three states, I would call it the "Little Tri-State Tornado" - though it certainly isn't little or weak, just in comparison to the one in 1925.
 
I certainly would concur, Greg as it started in Arkansas, cut across the Missouri bootheel and went well into Tennessee. Crossed three states, I would call it the "Little Tri-State Tornado" - though it certainly isn't little or weak, just in comparison to the one in 1925.
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Well, assuming the storm produced a continuous tornado across that area. I'm not sure that's verified yet.
 
Well, assuming the storm produced a continuous tornado across that area. I'm not sure that's verified yet.
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Looking forward to the surveys on this one for sure to see the verification (or not) of this.
 
The KFVS web site original linked here has a second story "Deadly storms move across the heartland" that does indeed show the time lapse radar, showing it moving from the Caruthersville/North Pemiscot area over north Dyer and north Gibson counties where the greatest loss of life occurred.

It also looks like, given the track on radar, these from the same system that my son and I saw way off to our east. Amazing...the Bentonville area is quite "gun-shy" right now due to the tornadoes of three weeks back...if the folks here had known what was brewing to the east of them, heading east...

We were SO blessed that our own "tor" came through at 10:00 pm rather three-five hours earlier, although what we got was bad enough.
 
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