May 4, 2007

Statistics:

Initial Target: Great Bend, KS
Departure: Naperville, IL 9:40 pm CDT May 3
Arrival: Smith Center, KS 1:00 am CDT May 5
Intercepts: Lebanon, KS
Tornadoes: 1
Hail: Severe (0.75 - 1.00 inch estimated)
Wind: Non-Severe (not measured)
Features: Rope Tornado, Wall Cloud, Inflow Tail
Miles: 978

Summary:

First chase of two in a run to Kansas with Chad Cowan.  Targeted Great Bend, KS near triple point awaiting late initiation.  Met chase convergence in Great Bend and hung around until a storm fired to the north in the early evening.  Played catch up on north moving cell and intercepted well after dark north of Lebanon, KS.  Intercepted new supercell with hook to the west after scraping severe hail core on the first storm.  Noted large wall cloud with and very long inflow tail.  Brief, rope tornado formed east of the wall cloud at approximately 11 pm.  Intercepted new storm further west but base appeared to have gusted out so called it a night, getting a room in Smith Center, KS

Crew and Equipment:

Chase team included Skip Talbot and Chad Cowan.  Equipment consisted of a TH-F6A Tribander, and GPS/Cell Phone equipped laptop.  Photography by Chad Cowan.

Details:

The models were coming together for a two day setup in the Plains as a trough ejected.  Friday's setup looked to be a late show, with the 500 mb winds not arriving until the evening.  The directional shear was fantastic, however, with backed surface winds and a strong, veering low level jet.  I was going to chase this weekend solo initially, but Chad changed his mind at the last minute (I was literally walking out the door) and agreed to come with.

Chad caught the Metra train out of the city and I picked him up at the Naperville station at about 9:40.  With two people now, we could drive a little longer, and get a little more sleep.  We drove straight through the night, taking turns sleeping in the back.  I had a regular twin mattress in the back of the Mudpuppy for this chase, and it worked a lot better than the air mattress.  We stopped at Chad's house in Manhattan, KS and crashed for a few hours before continuing down to our target of Great Bend, KS.

There was a seven car chase convergence in the parking lot of the Arby's in Great Bend.  I got to meet a few chasers including Michael and John O'Keefe, Jay Caziel, and a couple of chasers from Quebec whose names escape me.  The cu field above us scooted off to the east, and the anxious convergence broke up to pursue.  We were still on the moist side of the dryline, however, so Chad and I stayed put, figuring initiation still might be further west, north, or south.
Chad and I bummed around for awhile before I came up with the idea of eating dinner to spur on initiation.  "Something always happens during dinner."  Sure enough, a tower went up to our north.  We paused briefly to check radar before we blasted north after it.
The storm was taking off.  It wasn't severe warned yet, but was showing an overshooting top. 
Despite speeding like a madman, I wasn't making any ground on this storm.  It was at least 60 miles to our north when we first spotted it, moving north away from us.  With the sun slipping below the horizon I knew we weren't going to intercept until well after dark.
According to Spotter Network, the College of Dupage chase team was just up the road from us, but we never caught them.  They continued north and we broke east to get out ahead of the storm before intercepting.  We finally got under the base at about 9:30.  There was a good amount of lightning but no discernable features.  The Doppler On Wheels passed us as we stopped just north of Lebanon so we figured we were in the right spot.

After watching this storm for awhile, the radar indicated a great looking supercell going up to our west with a hook.  Our west option took us through the core of the storm we currently on though.  We proceeded north with caution, scraping the edge of the core as our storm passed overhead.  We started getting hit with some hail up to 1 inch in size so we stopped and actually backed off for a few minutes before continuing on. 

We lost data so I couldn't tell where the core from the current storm ended and what the storm we were after was up to.  Losing data at night is a terrible situation to be in that has lead to white knuckle terror several times in the past.  I plotted an intercept route based on an old scan and we took our west option, an unpaved county road.  The radar finally updated.  The storm had turned right much harder than I anticipated, and the center of the circulation was now heading east northeast.  The circulation would still pass us to the north, but it was much closer than I originally thought.

A large wall cloud and tail appeared, backlit by lightning.  This storm was looking very promising.  I spotted some cows on the side of the road and I suggested we stop and use them for an interesting foreground in our photos.  We pulled into the drive of a ranch and crossed the road.  The gate was open so we walked into the field.  The lightning flashed, illuminating horns.  "Those are bulls," Chad said, and we stopped in our tracks.  Lightning flashed again and I saw shaggy hair and a hump, "No... those are bison," I said.  Now we started backing away.
We watched the wall cloud for awhile.  The lightning on this storm was fantastic with strikes every 10-20 second.  There were two standing bison and a calf laying in between them.  A few minutes went by and they didn't move once.  "Those are statues," Chad concluded.  "Well, maybe they are just sleeping," I suggested.  Chad moved forward, but I held my ground.  There was an electric fence surrounding them, but the bison never moved.  They were indeed statues.
An inflow tail stretched out for miles ahead of the wall cloud.  There was substantial inflow winds at our location as well, gusting to at least 30 mph.
At 11pm a funnel shaped lowering well east of the wall cloud had my attention.  We dismissed it as scud originally, but the feature persisted.  It then appeared to descend as a rope tornado.  The backlighting on this feature was so poor that my video camera couldn't pick it up at all and Chad barely managed to get this shot of it.
Extreme contrast enhancement shows what we are fairly sure was a rope tornado on the left side of the image.
The lightning behind the wall cloud was much more vibrant.  A local pulled up in his pickup truck asking what we were up to.  I told him we were chasing, and, unimpressed, he said we were spooking the elderly couple that lived at the ranch.  I moved my car out of their drive onto the gravel road.  There was no shoulder, but there was also no one on the road... except for COD.  The College of DuPage chase team drove past us a few minutes later, coming from the west, and I gave them a wave.
Chad and I watched the storm until it gusted out and fell apart on the radar.  Another storm went tornado warned to out southwest, so we dropped down to it.  It was nowhere near as impressive in appearance as the last storm, and appeared to have an occluded base.  We did note the winds shift from inflow to outflow several times though.  When this storm started to die it was after midnight.  We decided to call it a night and get some sleep for tomorrow's chase.
We got a room in Smith Center, KS.  The friendly, yet incomprehensible clerk (not unlike the Cajun from The Waterboy) informed us about the devastation to the south in Greensburg.  We were oblivious, having only watched KUEX's radar the entire evening once we were on the chase.  We turned on the news to see shocking scenes of damage and reports that people had been killed..
Conclusion:

The first tornado ranked EF5 (Enhance Fujita Scale) occurred on this evening, and it was the most powerful tornado since May 3, 1999.  Chad and I wound up on a different supercell far to the north, while the Greensburg EF5 was about 60 miles from our original target area.  I have mixed emotions about missing that storm.  Part of me wants to have been there to see such a legendary storm, yet at the same time it was ranked EF5 because of the horrific damage that it caused, and it would be sickening to hear about the loss of life.  There is also the safety concerns.  We probably would have intercepted the storm from the north and if we wound up inadvertently core punching the storm, or trapped, the situation could have become extraordinarily dangerous.  My condolences go out to those affected by this storm, and my applause to the National Weather Service for their timely, strongly worded warnings that undoubtedly saved lives.

This chase was successful in terms of tornado interception, however, it was a brief, non photogenic event.  However, the supercell structure that we did witness, including the ability to feel the strong inflow, was very impressive.

Post analysis of the vent shows remarkable conditions over the Greensburg area.  Jon Davies' analysis of that evening actually showed that the RUC analysis was wrong, placing the dryline too far east, and that parameters over the Greensburg area were more than comparable to other violent tornado events.

Jon Davies' Analysis

 

Radar Analysis with GPS Overlay:

KUEX Animated GIF (3.5MB) Individual PNG Frames - Chase Analysis
KDDC Animated GIF (4.6MB) Individual PNG Frames - Greensburg EF5

 

Lessons Learned:

  • Do not trust the models, even the RUC analysis, and carefully study the current conditions, as the original target area may still be primed for the best show.