2016-05-25 REPORTS: KS/OK

[Lanny Dean]

After having missed the 24th DDC event due to miscommunication and being out of position for whatever reason, we finally arrived and staged in McPherson early afternoon with many other folks. Watching the northern boundary, we collectively decided to go north on the developing cell nw of Salina. While we had the tour guests, we also had a support vehicle (@Marcus Diaz )

Racing north on 35 past Salina, a large lowered base came into view with attendant large wall cloud. Roughly 3 miles south of 18 HWY we documented the first cone type tornado while still continuing north. at HWY 18 and HWY 81 we went west on 18 and stopped just east of the intersection to reassess. At this location, I decided to try and make a play in getting the INPAR placed. As such, Marcus and I raced west on HWY 18 ultimately stopping and dropping the INPAR location: 39.01.67.09N -97.67.60.97"W. At this location we noticed a bowl shaped funnel but did not see any ground contact. After placing the INPAR in the ditch, we decided to move back east towards our group and let the supercell and associated funnel move towards the INPAR and towards us. While difficult to tell if any ground circulation was present, Marcus did notice grass falling from the sky at our location: 39.01.62.86N -97.65.87.51W. Just west of this location a small cone type funnel was documented and then a thin slender rope that passed roughly 60-65meters south of our location. Video documented complete Tornadogenesis twice well before the tornado really anchored east of Bennington.

Prelim results and findings from PACRITEX project from the 25th and documentation from the INPAR suggested that the circulation and attendant funnel/small tornado had passed directly over the INPAR.
A full data set was obtained including pressure perturbations and acoustics. A preliminary 63mb free stream pressure drop was documented on HWY 18 west of Bennington, KS: 39.01.67.09N -97.67.60.97"W. However, after gain adjustments, (noting gain set too high) the correct pressure drop was 23.2mb at that location.

Moving east we positioned ourselves right up under the updraft base after encountering a few baseballs trying to hook slice as we had no choice but to get closer. Upon receiving northerlies we retreated back north and stopped just in time to watch the main tornado anchor roughly 200 yards from our previous position.
After the tornado anchored east of Bennington, KS, it became a very strong stove pipe as it continued to ride the boundary, ultimately becoming a very long track tornado. The tornado remained on the ground for almost 90min and has been rated as an EF-4 prelim with estimated wind speeds of 180mph. A second attempt to place the INPAR in the direct path was discussed by Dean and Diaz but the tornado shrouded itself (pulling an El Reno) and the angle of approach was canceled. However, at 01:16:10 Dean did place the INPAR on the ground: 38.917797N -97.120953 and recorded a signature at 4.4Hz with an increase in amplitude nearing 27db. It should be noted that the strongest TSF was documented and recorded at 01:21:37 with an increase in amplitude nearing 32db at 6.9Hz.

As of this post date, documentation clearly show 2 separate frequency signatures @ 4.4Hz and 6.9 to 7.2Hz. At roughly 1:23:10 onwards, the frequencies changed dramatically in amplitude and signature. I suspect these changes due to the Doppler effect with regards to our position. Many thanks to Marcus Diaz and @Conor O'Neill for assisting and shooting video as I drove and concentrated on the tornado. Many thanks to Jodi Mair and Jeffery Thornton for assisting with road networks after the cluster and literal fist fight we saw on the county road.

Video link below as we placed the INPAR probe and tried to stay with the supercell.

 

[Lanny Dean]

CORRECTION: The correct static free pressure perturbation drop was 23.2mb NOT 43.2 as outlined above. I fat fingered the key. MOD's can you adjust as I cannot edit the original post att?
Thank you

 

[cdcollura]

Good day all,

May 25 was a pretty interesting chase day for me, with interception of an LP storm near El Dorado, Kansas, THEN a long range intercept of the long-track violent tornado from Solomon to Chapman, catching the most intense phase of that storm's end of its 90+ minute on-the-ground lifecycle! What a day, and here's the long-awaited log for this chase day below...

1). May 25, 6:00 PM - Interception and observation of a severe thunderstorm near El Dorado, Kansas in Butler County near Highways 254 and 77. This storm was an LP supercell storm, with an impressive "barber pole" updraft, and striking visual appearance despite its small size. The storm core was small and probably had 1" hail, but was not penetrated. The storm undergone downscale evolution and basically evaporated after a couple of hours. Conditions causing the storms were surface heating, a dryline, low pressure trough, and upper trough. A 2009 Ford Escape SUV was used to chase the storms. Documentation was HD video, time-lapse, and digital stills. A tornado watch was in effect for the area until 9PM CDT.



Above: Low precipitation (LP) supercell rotating hard near El Dorado, Kansas on May 25, 2016. This storm weakened via downscale evolution and essentially evaporated in a stronger cap. Attention turned to a distant tornadic supercell in the northern fringes of the target area for the day.

2). May 25, 8:30 PM - Long-range interception, observation, and indirect penetration of an extremely severe and violent cyclic long-track thunderstorm from near Abilene, Kansas and I-70 in Dickinson County. This storm was first observed from a 100 mile distance, with an overshooting top (probably to 60,000 feet) and a long-range intercept was done given the fact that is was in a great environment for tornadoes, despite SPC outlooks. When the storm was finally intercepted east of Abilene, a large and violent wedge tornado, up a mile and a half wide, was observed at close range west of Chapman and crossing I-70. This was an extremely powerful tornado, which was supposedly on the ground for a staggering 90+ minutes! Damage observed was trees debarked and ground scouring. The tornado did extensive damage to anything it hit. In addition, 70 MPH winds, tennis ball sized hail, frequent lightning, and horizontal rain was encountered with this storm. Conditions causing the storms were surface heating, a dryline, low pressure area, and upper trough. A 2009 Ford Escape SUV was used to chase the storms. Documentation was HD video, time-lapse, audio, and digital stills. A tornado watch was in effect for the area until 9PM CDT.



Above: Here is a picture of an overshooting top, probably 60,000 feet high, from 75 miles distance of a tornadic supercell storm currently near Salina, Kansas. This was the storm that will have a tornado on the ground for nearly two hours! I am heading north (after being "suckered" south to a dying LP storm) for a long-range intercept.



Above: RFD clear slot and violent tornado from 5 miles away, and to the ESE of Abilene, Kansas approaching I-70.



Above: Violent wedge tornado near Interstate 70 and not far from Chapman, Kansas. This is about a half of a mile away, close enough to FEEL the roar of it!



Above: Wedge tornado at its most intense crossing the ENE jog of I-70 and headed just south of Chapman, Kansas after being on the ground for 90 minutes. The white streaks falling are hail stones to tennis ball sized. The object in the highway to the lower left is a large turtle crossing the road!



Above: Tornado now over the Interstate. Traffic stopped and police creating a rolling roadblock so no one drives into it. Incredible motion. Wedge tornado now about to graze the south side of Chapman, Kansas. This tornado was rated at LEAST EF-4, with winds strong enough to bend railroad tracks!



Above: A pile of debarked mangled trees swept up the embankment on the south side of I-70 near Chapman, Kansas. Also note the grass is almost gone and the ground has been scoured to bare dirt.

 

[jaredleighton]

Gotta give an assist to my chase partner for this day. I was all set to have a day off after the previous 5 days were so active, and the next day was anticipated to be the big coup de gras. We decided to have lunch in Hutchinson to wait out the day and tell stories about the previous tornado fest near Dodge City. Like others, we were tempted by a few decent towers to our south, but ultimately opted to head north/northwest to some developing CU in NC Kansas.

The storm became mature while we were entering McPherson from the west, causing the slow creep through McPherson to be borderline torturous. Finally, we made it to I-135 and raced north to I-70. We found a nice little vantage point, with a bunch of other chasers at I-70 and Niles Road. Our initial impressions of the storm were somewhat unfavorable, mainly because the base appeared to be a bit skinny, and radar representation seemed like it was maybe on a down cycle. Just about the time we remarked about how the storm needed some help, the base immediately expanded with new updrafts and all of a sudden it looked much healthier. Not much longer after that the initial cone tornado formed, and quickly grew into the beast that it was. We generally kept our distance from the tornado and paralleled it along I-70, until it crossed somewhere near Enterprise. We ultimately lost sight of the tornado as we were about 1 mile or 2 south of Chapman, but we could certainly hear it's jet-like rumble coming from within the rain.

For a more detailed account of this day as well as more photos, see my full write-up.

We never got incredibly close to the tornado, but the long distance vantage points offered some fun shots of the entire storm/tornado structure.


This shot was taken shortly after initial formation looking north on Niles Road, just north of I-70.


Same vantage point as the previous photo, but after the tornado grew in size.