Topic: April 21 to April 24 2007 Tornadoes - Tornado Alley

[Jimmy Deguara]

Incidently, it may be of interest that this system (24th April event) produced coldy post frontal tornadoes in Colorado/Western Kansas border (snowing one county west of the tornado), warm sector massive HP supercell killer tornado extreme SW Texas, tornadoes along the squall line in central Texas, and the central Kansas low topped supercells forming along the dryline - so tornadoes in all 4 sectors of the low pressure system.

Regards,

Jimmy Deguara

[Michael Bath]

Congrats Jimmy and others on the chase.   I had been watching the VIS satpics and it was certainly not an indication of the conditions as it looked quite poor. Though of course tornado warnings were in place. 

Storm reports map for 24th April

[David C]

I must say the storm that initiated in Mexico and crossed the border into southern Texas had a very impressive signature. Otherwise it was not an atypical 'early' season high risk event - quite a common outcome - jack squat.

For anyone here who looks at the SPC convective outlooks and imagines that seeing a tornado is to be expected with every upper trough --- well, it isnt. Occasionally there will be a day (such as a few weeks back) where isolated supercells align north south over several states and drop long-lived tornadoes and anyone with a car would probably get lucky - these events are the exception. Most are a battle and to have seen a wedge tornado in Colorado on Saturday and then those tornadoes in Kansas really is excellent Jimmy.

Now, relax and enjoy the ridge for a while 

[Jimmy Deguara]

Hi David,

Just to add to what you had stated in terms of that Eagle Pass killer tornadic supercell near the Texas/Mexico border, the following is a reflectivity showing the supercell a very large supercell in that:

Regards,
Jimmy Deguara

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

Rated EF3 on the enhanced Fujita scale - interesting to note that perhaps a stronger tornado had been detected on the Mexico side.

Courtesy National Weather Service

[Jimmy Deguara]

On a separate note, here is the completed survey of the Plainview to Tulia supercell tornado damage survey:

http://www.srh.noaa.gov/lub/climate/Local_interest_events/2007/20070421_tor/

Regards,

Jimmy Deguara

[Jimmy Deguara]

Hi,

I have images of the past several chases.

Please note it does not cover everything but at least

20th April 2007 - LP supercells south of Amarillo, Texas



More pics here http://australiansevereweather.com.au/photography/photos/2007/jd20070420.html

21st April 2007 2 Tornadic supercells with very large tornado - Colorado (tornado captured on video)

               

More pics here

http://australiansevereweather.com.au/photography/photos/2007/jd20070421.html

23rd April 2007 - LP supercell near White Deer, Texas



More pics here

http://australiansevereweather.com.au/photography/photos/2007/jd20070423.html

24th April 2007 Low topped supercell develops on triple point in central Kansas producing two tornadoes - (one of the tornadoes produced multiple spin ups).



More pics here

http://australiansevereweather.com.au/photography/photos/2007/jd20070424.html

Regards,

Jimmy Deguara

[Michael Bath]

Hi Jimmy - very impressive set of images of the 24th event in particular. I am amazed such a small looking cell produced those two tornadoes.  You guys sure got into a perfect position to observe this with great contrast. Fantastic !

Will have to review the soundings to see what shear was in place.

The rest of Jimmy's photos for these dates are here:

20th April

21st April

23rd April

24th April

MB

[David C]

On a separate note, here is the completed survey of the Plainview to Tulia supercell tornado damage survey:

http://www.srh.noaa.gov/lub/climate/Local_interest_events/2007/20070421_tor/

Regards,

Jimmy Deguara

EF2! These were very photogenic tornadoes thanks to the somewhat high basis and just beautifully visible storm structure. As ludicrous as it is to make such claims,  and indulge me for just a moment, the rotation in your video is what I associate with F4 / F5 Jimmy - I just watched it again -- just crazy motion Jimmy and thank God there were no farms / towns in the path of that.

Now, the your photos of the low-top tornadic supercell are just great!  Look at the first photo - NO anvil.....but look at the cyclonic curvature in the base....brilliant tornado there demarcating the centre of circulation!

[Jimmy Deguara]

Hi David,

Well I don't think your comments are unfounded certainly the shear profiles for strong to violent tornadic storms. I guess the CAPEs were lower in this region but there was rapid destabilisation lifting off that lid.

Has anyone come across radar for this event or know of an archived site. Might try the UCAR website - I'll check there.

Found a website that retrieves any form of data from the archives.

Regards,

Jimmy Deguara

[Dave Nelson]

Hi David,
Well I don't think your comments are unfounded certainly the shear profiles for strong to violent tornadic storms. I guess the CAPEs were lower in this region but there was rapid destabilisation lifting off that lid.
Has anyone come across radar for this event or know of an archived site. Might try the UCAR website - I'll check there.

Found a website that retrieves any form of data from the archives.

Regards,
Jimmy Deguara

where's that web site,  Jimmy  ?    look forward to being able to possibly getting data from previous large storms.


 Also... looks like a new set of storms developing in Mexico and heading towards the NM and TX borders, on the radar.
I wonder where you are at the moment Jimmy ?

just looked at the SPC convective outlooks...

...SERN AZ EWD INTO SWRN TX...
   SONORAN UPR LOW WILL BEGIN A SLOW EJECTION ENEWD TOWARD THE AZ/NM BORDER BY 12Z.  SEVERAL SHORTWAVE TROUGHS WERE ROTATING AROUND THE LOW.  ONE WAS MOVING INTO SERN AZ WITH AN UPSTREAM IMPULSE
   APPROACHING THE SRN NM/SWRN TX INTERNATIONAL BORDER THIS AFTN.   RELATIVELY STEEP LAPSE RATES ALOFT...DIFFERENTIAL HEATING ALONG THE HIGHER TERRAIN AND INJECTION OF MODEST LOW-LEVEL BOUNDARY LAYER
   MOISTURE FROM THE PLAINS HAVE BEEN INSTRUMENTAL IN TSTM DEVELOPMENT

maybe the place to be, ..   there are other areas of convection along the the eastern edge of the rockies
overall the risk seens in SPC's view  low risk of severe storms

cheers
Dave N

[Jimmy Deguara]

Low risk of severe storms alright. That is a long way from Dallas. I'll await the next bunch of action perhaps by early May.

Regards,

Jimmy Deguara

[Andrej Matko]

Great pics Jimmy, that LP near White Deer - amazing stuff!

This is the site with archived radar, sat and other data.

http://www.rap.ucar.edu/weather/radar/