4/24/07 DISC: TX / OK / KS / CO

[Danny Neal]

I am just now hearing of the Eagle Pass Tornado. It will be interesting to see if a language barrier came into play here. I used to know a few people from SW Texas and they would tell me how alot of them spoke only spanish.

 

[Bill Hark]

am just now hearing of the Eagle Pass Tornado. It will be interesting to see if a language barrier came into play here. I used to know a few people from SW Texas and they would tell me how alot of them spoke only spanish.

I was worried about that last night, especially just over the border in Mexico. Mexican tornadoes are less common. I don't know if their warning system is effective. Below is an image of a storm with TVS and 69 dbz moving toward the US border from Mexico. I saved it from WeatherTap at 11:30 PM April 24. I don't remember the time stamp but they are usually within 5 minutes. Eagle Pass is just over the border from Piedras Negras.

Here is a link to some storm info. BTW, the tornado in the small picture was from Colorado.
http://www.delrionewsherald.com/wire.lasso?report=/dynamic/stories/S/SEVERE_WEATHER



Bill Hark

 

[Jeff Snyder]

Ive uploaded quite a few radar images of the supercell as it was near and over Eagle Pass (BR1, BR2, SRV1, and SRV2, primarily) --> http://www.tornadocentral.com/now/eaglepass/

I also uploaded a bunch of *.rv3 files for those who use GR3 --> http://www.tornadocentral.com/now/eaglepass/GR3/ . Just right-click, save as, and then drag the file(s) into an open GR3 window. You may need to make sure you have BR1, BR2, SRV1, and SRV2 products selected/opened (some have SW, as well).

 

[Andy Wehrle]

Thanks for posting those radar images, Jeff.

I don't know about everyone else, but Tuesday did not turn out anything like I anticipated. In the days leading up to it, I fully expected a classic Plains outbreak with six or seven echoes much like this (and corresponding with this) lined up along the dryline from central Kansas to north-central Texas by mid-afternoon.

Then the wind profiles got all screwey, and the crapvection-fest began.

First, my hat's off to those of you who got on the Newton area storm, seeing as it was the only decent tornadic supercell of the day NORTH of Eagle Pass. Second, hats off to SPC for holding back and not high-risking the entire Plains area in the morning, which I would have done based on anticipating the aforementioned scenario.

However, I am curious and would like to hear from somebody at SPC about the decision to high-risk central and northeastern Texas at 20Z and maintain it at 01Z. What were you seeing that made that area appear more favorable for an outbreak of strong/violent tornadoes than other areas of the Plains yesterday? It seems that the strongest storms of the day did a pretty good job of avoiding the high risk area:

 

[Kenny Drake]

I thought I was the only confused person yesterday as to the sudden turn of events. I feel a bit better now seeing that SPCs HIGH risk did not pan out, at all. In fact I dont think there are any severe wx reports in the HIGH risk. I think the main reason for the Oklahoma bust was the dryline plowing east in the morning with a small CAP just ahead of it. Personally, I've never been a fan of fast moving drylines, whether it plows east throughout the whole day or just part of it. I think the worst case scenario is it decides to plow east in the morning, fires up widespread convection which drains the moisture.

 

[John Peters]

The eagle pass tornado has been rated EF-3 with a path length of 1 mile and a path width of 1/4 mile, maximum winds around 150 mph. There are reports that at least two other tornadoes touched down in Mexico, one of which was reported to have been a large tornado.

http://www.srh.noaa.gov/ewx/html/wxevent/2007/eaglepass.htm

 

[Rich Thompson]

Several of you know I work at SPC, and I was in the operations area much of Tuesday. The lead forecaster on duty happened to ask for my opinion of the situation around 16z, and I can say that my input helped sway the forecast away from HIGH risk at that time. The 20z upgrade occurred while I was picking up my kids from school.

Rich T.

 

[Greg Stumpf]

Either the NWS added one more tornado to the preliminary map or I missed one of them earlier, but the total is now up to 8 tornadoes on the McPherson storm according to the National Weather Service. I'm not trying to be a wise a$$ either with the counting comment mods, so please don't give me with another infraction. Honest to god the map either got updated or I missed one.
http://www.crh.noaa.gov/ict/scripts/viewimage.php?STORY_NUMBER=2007042505&IMG_NUM=7&loc=remote
I am making a copy of my video for the NWS to hopefully help out with determining the number of tornadoes and locations/times. After watching it while I uploaded it to my computer I believe we had a total of 6 different tornadoes on Tuesday, all of them were well seperated in both space and time. I am going to do my best to mark locations and times on a map and I will post the results along with video tomorrow.

Bear in mind that the information the NWS uses to make these reports is comprised of what the spotters and chasers are supplying to them. It is doubful that they conducted a damage survey, and even if they did, these tornadoes were too weak to determine the ground truth from damage patterns. So if bad data is supplied to the NWS, then bad verification results. It is up to us to ensure that the verification is as close to the truth as possible.

Anyway, whatever information you can carefully glean from your log/photos, and others' logs including my own, will certainly help pin down the truth. However, looking at that NWS map, I can safely say that the location of the initial tornado is incorrect. It should be about 3/4 mile WNW of the intersection of 4th Ave and Sterling Rd. This NWS map also appears to contain the approximate positions of all the spotter reports on the storm, containing many duplicates and errors in location (spotter locations, or incorrectly estimated remote positions). I can confidentally say there were 2 to 3 specific tornadic circulations, each from the same parent mesocyclone (no occlusion hand-off ever took place). Each tornado had period of strengthening and weakening, which should not be confused as separate vortices, nor a "skipping" vortex (the latter being a common tornado myth).

 

[Mikey Gribble]

I totally understand Greg. I was up at the NWS Wichita office a few hours ago. They are very aware of the duplicates and innacuracies of the current map. We compared the video and locations of what I had to the other reports and video they have recieved from several other chasers. I am sure that map is going to change and duplicate reports will be removed. I know for a fact that the tornado NW of Nickerson 1 mile crossed just South of 96th Avenue because it was only 100 yards in front of us. They seemed to think they were going to go with 6 seperate tornadoes. This kind of stuff obviously always causes some controversy since determining what constitutes a new tornado is largely arbitrary. That being said, I was told by the meteorologist at the weather service that my report is coming in very closely with what they recieved from the other chasers they got video from and I think there was one NWS employee that might have given them some input too. I am sure they would greatly appeciate any input anybody has on locations and times also. I was struggling to figure out my locations during the video. All I had to go off of was a few points in the video where I stated my location while I was doing call ins to KWCH.
On Tuesday I called it a new tornado when it was seperated in both space and time. I don't mean physical distance on the ground when I say space. I mean a new area of circulation on the base of the updraft that was well seperated from the area of the previous tornado. We were right underneath it all night and several of the tornadoes we saw were coming from small lowerings and areas of rotation that would develop along the RFD slot and slowly work there way North around the RFD slot. I have one great piece of video with two tornadoes at the same time that will show this perfectly. I will put a grab up of it when I get home from work. Two of the tornadoes I saw in particular would have been very difficult to notice unless you were in very close and didn't have any obstacles obstructing your view of the ground circulation. These were all very weak tornadoes and they didn't all have easily noticeable funnels and the ground circulation was very brief on several of them. On one in particular we didn't even see the funnel before it touched down. We saw the circulation at the surface ahead of us and then looked up and saw a small nubby funnel above it. I think a lot of tornadoes were missed by a lot of people because they were very weak and very short in duration, but still a tornado none the less. From what I've seen and heard, a lot of people are reporting 3-4 tornadoes and then another large group is reporting 5-7. It will all get figured out I'm sure.

 

[Jordan Hartley]

Im not seeing or even hearing anything about the small outbreak that took place in E CO for this date. A family member told me that sheriff deputies were reporting tornadoes traveling due west. What happened in E Colorado on Tuesday?

 

[Mikey Gribble]

I guess the mods moved the posts from the Reports thread. Here is the sequence I was talking about. I have been going over my video repeatedly for hours and I am very confident in my report of 6 seperate tornadoes after that. I honestly don't think the discrepancies have as much to do with definition of a seperate tornado as much as it has to do with your location on the storm after going over the video closely. I can't emphasize enough that we were right underneath this all night. Ryan, Lindsey and I were in perfect position to see every little spinup. I am going to put together a full sequence of all the tornadoes I counted and locations (to the best of my recolection) hopefully tomorrow, Saturday at the latest and I will post that in the Reports thread.
Here is the sequence that shows what I was talking about earlier that shows what I was calling seperate tornadoes on Tuesday. Click on the pictures to enlarge.

We were driving East in this first picture and a tornado was on the ground NE of us about 200 yards.


This next picture was a little further down the road, still driving East. You can see the tornado from the first picture at the top of the screen and a seperate lowering/area of rotation in the distance on the northern edge of the RFD.


The next picture is shortly after the last one just further East down the road. You can see the tornadic circulation on the ground right in front of us(and the very bottom tip of the funnel associated with it at the very top of the screen) and the former lowering in the background to our North is now becoming a funnel.


In this next picture we have turned North onto another road and are now looking to the NW. The tornado from the last pictures is now just a funnel and it is located at the top center of the picture. The funnel that was in the background from the other pictures is now becoming better defined on the far left side of the screen.


Another picture of the same two funnels zoomed in more.


This last picture is just to show conformation that the newly developed funnel did touch down. You can see dirt getting picked up by the tree line in the distance.


Now, would I count those as two seperate tornados, absolutely. They were well seperated in space (at least 3/4 of a mile) and they came from two seperate distinct areas of rotation. It's not like it was vorticies spinning up around the center of a mesocyclone. This wasn't an early on multi-vortex tornado situation where you get tons of spin up vorticies around a common center of rotation.
Like I said before, I will try to put up a detailed report with pics from all 6 tornadoes from Tuesday and get it posted by this weekend. I am also going to see if the guys at the NWS have time to see me again tomorrow because I now have a much better handle on exactly what happened after watching my video for hours on end.