4/22/10 DISC: CO/KS/TX

[Marc Buschmann]

WOW very nice Pictures.
Greetings from Germany
Marc Buschmann

 

[Jeff House]

Congrats to all who intercepted! The tornadoes were textbook cases of enhanced low level shear near boundaries promoting cyclical supercells. Other boundaries, in addition to the DL, tend to make the difference between brief spin-ups and long shows. I could not go but thanks to all for great Now and Reports threads.

First CO went on the warm front and KS followed. The synoptic WF ahead of the DL is pretty straight forward. Despite lower CAPE compared to TX, the excellent low level shear did the trick. One thing about the High Plains: A little upslope goes a long way. The tornadic cells were able to stay right on the warm front, without crossing onto the cool side, producing nicely. I like those pix Derek Shaffer posted; awesome with the changing light. Nice pix from everyone else too.

The TX Panhandle was a popular target, one I wrote more about in the FCST. Morning rain deposited an outflow boundary OFB intersecting the DL. I love those setups! The OFB became diffuse on the sfc chart by early afternoon. However a perturbation in the low cloud field remained on visible satellite. Patiently following the OFB paid dividends. By late afternoon SE sfc winds had increased esp on/near the OFB. The monster most chasers followed was riding right along the OFB much of the time. It was that OFB that likely promoted such a long show. DL bulge was nice to get the sups started, but I believe the OFB is what kept the show going so long. Enjoyed following the action from the office.

 

[Jay McCoy]

Here is the preliminary storm damage survey from NWS AMA..A total of 8 tornados so far.

http://www.srh.noaa.gov/news/display_cmsstory.php?wfo=ama&storyid=51285&source=0

April 22, 2010 Severe Weather Event

...NATIONAL WEATHER SERVICE DAMAGE SURVEY CONFIRMS AT LEAST EIGHT TORNADOES ACROSS THE EASTERN TEXAS AND OKLAHOMA PANHANDLES ON THURSDAY APRIL 22 2010...
THE FIRST TORNADO TOUCHED DOWN 5 MILES NORTHEAST OF GOODNIGHT IN ARMSTRONG COUNTY AT 459 PM AND LIFTED AT 502 PM CDT. THE TORNADO WAS ON THE GROUND FOR ONE TO TWO MILES WITH A MAXIMUM WIDTH OF 50 YARDS. THE TORNADO WAS RATED AN EF0. NO DAMAGE OR INJURIES WERE REPORTED.
THE SECOND TORNADO TOUCHED DOWN 4 MILES SOUTHEAST OF GROOM IN DONLEY COUNTY AT 510 PM AND LIFTED AT 526 PM CDT 2 MILES EAST SOUTHEAST OF JERICHO. THE TORNADO WAS ON THE GROUND FOR 8 MILES WITH A MAXIMUM WIDTH OF 100 YARDS. THE TORNADO WAS RATED AN EF0. NO DAMAGE OR INJURIES WERE REPORTED.
THE THIRD TORNADO TOUCHED DOWN 3 MILES SOUTH OF GOODNIGHT IN ARMSTRONG COUNTY AT 520 PM AND LIFTED AT 543 PM CDT 8 MILES NORTHEAST OF GOODNIGHT. THE TORNADO WAS ON THE GROUND FOR 11 MILES WITH A MAXIMUM WIDTH OF 100 YARDS. THE TORNADO WAS RATED AN EF1. TWO POWER POLES WERE REPORTED BROKEN JUST SOUTHWEST OF GOODNIGHT.
THE FOURTH TORNADO TOUCHED DOWN 8 MILES SOUTH OF BRYANS CORNER IN BEAVER COUNTY AT 551 PM AND LIFTED AT 552 PM CDT. THE TORNADO WAS ON THE GROUND FOR ONE QUARTER MILE WITH A MAXIMUM WIDTH OF 25 YARDS. THE TORNADO WAS RATED AN EF0. NO DAMAGE OR INJURIES WERE REPORTED.
THE FIFTH TORNADO TOUCHED DOWN 8 MILES EAST SOUTHEAST OF GROOM IN DONLEY COUNTY AT 607 PM AND LIFTED AT 609 PM CDT. THE TORNADO WAS ON THE GROUND FOR ONE HALF MILE WITH A MAXIMUM WIDTH OF 25 YARDS. THE TORNADO WAS RATED AN EF0. NO DAMAGE OR INJURIES WERE REPORTED.
THE SIXTH TORNADO TOUCHED DOWN 1 MILE EAST OF LAKE MCCLELLAN IN GRAY COUNTY AT 538 PM AND LIFTED AT 540 PM CDT. THE TORNADO WAS ON THE GROUND FOR ONE HALF MILE WITH A MAXIMUM WIDTH OF 25 YARDS. THE TORNADO WAS RATED AN EF0. NO DAMAGE OR INJURIES WERE REPORTED.
THE SEVENTH TORNADO HAD A LARGE...BROAD AND INTENSE ROTATION THAT PRODUCED MULTIPLE BRIEF TORNADO TOUCHDOWNS. THE TORNADO BEGAN 1 MILE NORTH OF LAKE MCCLELLAN IN GRAY COUNTY AT 630 PM AND LIFTED AT 652 PM CDT 4 MILES NORTH OF ALANREED. THE TORNADO WAS ON THE GROUND FOR 9 MILES WITH A MAXIMUM CIRCULATION WIDTH OF ONE QUARTER MILE. THE TORNADO WAS RATED AN EF0. NO DAMAGE OR INJURIES WERE REPORTED.
THE EIGHTH TORNADO TOUCHED DOWN 11 MILES EAST NORTHEAST OF LEFORS IN GRAY COUNTY AT 640 PM AND LIFTED AT 650 PM CDT 7 MILES WEST SOUTHWEST OF MOBEETIE. THE TORNADO WAS ON THE GROUND FOR 5 MILES WITH A MAXIMUM WIDTH OF 100 YARDS. THE TORNADO WAS RATED AN EF0. NO DAMAGE OR INJURIES WERE REPORTED.
THIS IS A PRELIMINARY REPORT AND IS SUBJECT TO REVISION BASED ON ANY NEW OR ADDITIONAL INFORMATION.
THE NATIONAL WEATHER SERVICE IN AMARILLO WOULD LIKE TO THANK LOCAL TELEVISION AND OTHER PRIVATE METEOROLOGISTS...EMERGENCY MANAGERS AND NUMEROUS LOCAL SPOTTER NETWORKS FOR TIMELY REPORTS AND DETAILED INFORMATION.

 

[Bill Tabor]

Does anyone know the tornado warning times / text for Groom Tx this day? I think I may have been in part of the circulation.

 

[Jeff Snyder]

Does anyone know the tornado warning times / text for Groom Tx this day? I think I may have been in part of the circulation.

Bill -- I'll refer you to the IEM Cow page at http://mesonet.agron.iastate.edu/cow/ , where you can search past warnings (based on start and end time, NWSFO, warning type, etc.) and see verification stats, etc. That's actually a really good resource for other met info as well.

For your specific request, try this search

 

[Marcus Diaz]

Alright, I'm in need of some help here guys. I intercepted both main storms in the TX panhandle this day and saw tornadoes with both storms. After going through footage, pictures, and timing them with NWS out of AMA, I counted 8 tornadoes. But according to the NWS, all those tornadoes that touched down NE of Alanreed were counted as 1 tornado, since they all came out of the parent circulation.

I saw 5 different "tornadoes" come out of this circulation, different funnels I should add, and all touched down in a different spot from the prior tornado. I was pretty sure that if a tornado touched down, completely lifted/dissolved, then some time later a new tornado touched down in a different location, it was considered a whole new tornado. Can someone fill me in on whats correct here?

 

[Jeff Snyder]

Marcus,

Well, I think for sure that it wasn't a single tornado N of I40 with "supercell B". When we turned NNW out of Alanreed, we saw one tornado just N of I40 (I was driving and didn't snap of photo, though contrast was low anyway), and another low-level meso to its N. These were distinctly-different circulations. While watching the northern meso (the tornado just N of I40 was more rain-wrapped and more difficult to see, IIRC), we saw several vortices with full condensation to the ground; these vortices were along the periphery of the meso, and they all rotated quickly around the center of the meso. Personally, I would call the first one of these (that moved quickly southward, then eastward on the back side of the low-level meso -- see THIS PICTURE and start at the 6:50 mark of THIS VIDEO) a distinct tornado, but the one (or two) that followed looked more like suction vortices associated with a low-level meso that was essentially extending to the ground (see THIS PICTURE and starting at the 8:30 mark of THIS VIDEO). In other words, after the tornado that occurred from 6:50-8:00 in the video, I think the subsequent vortices may have been associated with a larger (though not terribly intense) tornado with occasional full-condensation vortices. In my own opinion, then, I'd say there were three tornadoes (that I saw, at least) just N of I40 NE of Jericho to NNW of Alanreed associated with "supercell B". I can accept counting all tornadoes associated with the northern meso as being a single tornado, however, since the vortices were associated with the same low-level meso. Regardless, this still means at least 2 tornadoes from different areas of rotation. I typically "count" based on low-level meso, but this obviously can be tricky in situations like this...

We have at least one member that's a forecaster at the AMA NWSFO, so maybe he can share some additional info. I certainly imagine that, unless AMA has video of the event, they base their assessment on damage and/or radar data; there's really not much to hit out there, and some of these were pretty small circulations. I'm not sure how much video NWSFOs looked through on the internet to help them when it comes if, where, and when tornadoes occured in their CWA. Regardless, the asssessment you read from AMA is preliminary until the Storm Data logs are filled for this event in a few months.

EDIT: I think Skip's vidcap below (and end of his video) is the same condensation tube as the one the starts at 8:20 in THIS VIDEO. I agree that this can safely be considered to be a subvortex from an m.v. tornado. However, the first tornado with this meso did not have that typical 'lean' to it (where the condensation funnel tilts away from the center with height, a trait that seems fairly common with individual vortices within a mv tornado), and it persisted for a considerably longer time.

 

[Skip Talbot]

Marcus this is where counting tornadoes can be tricky. I think the key is trying to identify the tornado cyclone, the parent circulation. If I see one circulation spitting out multiple tornadoes in short succession I generally count those as one tornado. If I see the circulation occlude, the tornado rope out, and a new circulation quickly develop on a new part of the storm (generally NE) and produce, I see that as separate tornadoes. NE of Alanreed there was definitely a multi-vortex that looked like it was coming from a single circulation. The trouble is there were also lots of quick tornadoes that were spinning up before and after on the RFD gust front, so it gets tricky trying to pin down where and what everything was. For reporting purposes the NWS is basically going to see one track, and one tornado, as these tornadoes were so close and some were rotating a common point. They might even lump tornadoes from separate cyclones together if the tracks are close enough. You'll have to review your pics and video to see what might have been one large circulation or what was separate, but ultimately its up to you on how to tally your tornado count.

Here's a video cap of the multi-vortex. Another funnel similar to this one spun up just moments later:

 

[Wesley Luginbyhl]

I was probably further north of Alanreed than anyone else (didnt really mean too). I had a great view of all 3 tornadoes Jeff talked about from the other side of the creek(I have pics and will post them when I get a chance). Jeff sumed everything up pretty well what I saw. At a minimum there were 2 tornadoes that came from what look to be seperate areas of circulation within the broad area. I had to outrun the tornado Skip has a photo of back south along that highway. There were numerous chasers standing out by the fence line staring it in the face like nothing was there (I dont know if they saw it). I will post some of the photos I got north of Alanreed tomorrow that show each of these areas very clearly. I am kinda glad it didnt put something bigger down or I would have had to escape through the core.

 

[Rich Thompson]

FWIW, I'm calling that mess two tornadoes N of I-40 and N-NNW of Alanreed. The first tornado was buried in rain much of its existence, and the multi-vortex tornado clearly formed farther N from a different parent circulation.

Here's the first tornado N of I-40. The edge of the next circulation is on the right side of the photo:

The second tornado formed from the lowering/circulation shown to the right in this wide angle shot, with the remnants of the other tornado buried in the rain to the left:

Some folks like to count every brief spinup in a single low-level meso as individual tornadoes. I prefer to call it all one tornado, for the same reasons mentioned by Jeff S.

 

[Chris Nuttall]

We have at least one member that's a forecaster at the AMA NWSFO, so maybe he can share some additional info. I certainly imagine that, unless AMA has video of the event, they base their assessment on damage and/or radar data; there's really not much to hit out there, and some of these were pretty small circulations. I'm not sure how much video NWSFOs looked through on the internet to help them when it comes if, where, and when tornadoes occured in their CWA. Regardless, the asssessment you read from AMA is preliminary until the Storm Data logs are filled for this event in a few months.

I was on-shift during the assessment on Friday. With nothing but two power poles being damaged, it's very difficult to perform an assessment. Radar data was used extensively. I gathered the data and made some plots to overlay in GR2AE of all the tornado reports we had received. I was told later how big of a help that it was in reconstructing the event.

There are other forecasters at the WFO that are members here, and they had already gathered some pictures off of the REPORTS thread to aid in the assessment. However, to effectively use photos and videos, there needs to be extremely detailed information on the location where the photo/video was taken, time of the video, direction looking, and distance from the object in question. In these cases, radar would still be used to see how well those position estimate jive.

Unfortunately, I can't tell you more about how the assessment was done or the discussions that were had because I simply don't know. I had my ear in a phone all day trying to find any reports of tornado damage and other general hail/wind reports. I can tell you that the mets involved spent several hours trying to figure all of this out.

 

[mikegeukes]

Tornadoes and Hail 4/22/10, NWS Dodge city has some stuff on their site
http://www.crh.noaa.gov/news/display_cmsstory.php?wfo=ddc&storyid=51276&source=0