May 30, 2004

Statistics:

Initial Target: Vandalia, IL
Departure: Bolingbrook, IL 10:30 am CDT
Arrival: Urbana, IL 11:30 pm CDT
Intercepts: Fayette County, IL 5:00 pm CDT
Tornadoes: 0
Hail: Severe Penny Sized (0.75 inch)
Wind: Non-Severe (not measured)
Features: Possible Gust Front Vortices, Wall Clouds
Miles: 580

Summary:

SPC issued high risk with 25% and cross hatching for tornado.  Targeted Vandalia, near CAPE and helicity bulls eye.  Intercepted tornado warned storms in Fayette County, noticing unidentified ground level clouds, possibly gustnadoes.  Caught brief severe hail while core punching.  Chased ever more linear storms into Indiana before calling it a chase due to rain and nightfall reduced visibility. 

Crew and Equipment:

Chase team included Skip and Bob Talbot and Jenny Acosta.  Equipment consisted of a NOAA weather radio, cell phone, TH-F6A Tribander, GPS with laptop and mapping software.  Photography by Skip Talbot and Jenny Acosta

Details:

Looking at the Day 1 Forecast, this is one you don't pass up.  The Day 1 Tornado forecast went to 35% later in the day and extended into Indiana.  Taking a quick look at the RUC model, I settled on a CAPE and helicity bulls eye over south central Illinois.  Earlier model runs were pointing toward the St. Louis area and I was expecting to have to chase in the hilly jungles of Missouri.  The new forecasts however, pointed to the great chase country of central Illinois.  The target was set to Vandalia (which turned out to be a jungle in itself though).

 

Bob and Jenny were with me again on this chase.  Only 15 minutes into the chase, disaster struck on I-55.  The cargo pod thumped twice on the roof, a warning that gave me just enough to time to glance in the rear view mirror to see the top of the pod fly off and into traffic behind us.  Luckily, no one hit it.  The wind had gotten under it and sheered the clips and bolts holding it on right off.  We retrieved it and secured it with a padlock and some rope I was going to use to tie our camping tent down.

 

On I-57 a morning squall line that was triggering warnings had caught up with us.  A tornado watch had been issued early to cover this activity, so we pulled off when the gust front approached.  No rotation on this dangling shelf lowering.

We got hit with some heavy wind and rain in Iroquois County, while a severe thunderstorm warning was in effect.  Looking north after the line passed.

We stopped at the apartment in Urbana to drop off the cargo pod to prevent further incident.  I made use of the computer lab for a data update.  A mesoscale discussion talked about discrete supercells forming in front of the squall that had already fired in Missouri.    Three PDS tornado watches had been issued, one of them covering our target area.  We continued down I-57 to I-70.

We made it to Vandalia with blue skies overhead.  The library was closed of course because it was Sunday and Memorial Day weekend.  Chris my roommate, who lives in Vandalia, wasn't answering his phone.  I was able to get a hold of Nick for a radar update.  He informed me that there was a line moving through Missouri and a lone cell out ahead of it near St. Louis moving along I-70.

 

We continued west on I-70 hoping to intercept the lone cell.  A storm came into view near Greenville and we exited for the intercept.  My dad let us use his laptop with an Earthmate GPS and mapping software for our trip.  It came in real handy while navigating the county roads and looking for expressway exits.  Also of great convenience was having the computer plot intercept routes based on our current location for towns mentioned in the warning text.

With dews near 70 the sky was very hazy and it was impossible to gauge how strong the storms were visually or if there were any others nearby.  Our storm received a severe thunderstorm warning at about this time.  While the GPS mapping was great, data would have been invaluable.  We were on the northern cell/complex featured on the bottom of this image.  However, I would dropped to southern cell, in a heartbeat had I seen this echo.

There was no good viewing option from the front of the storm so we let it run us over and then chased it from behind.  We noted this rear flanking feature, which is either a really low base or a rear flanking shelf cloud.

We dropped south to get into better viewing and had to core punch to do so.  We caught some penny sized hail, my second encounter with severe hail.  This is about the time when our "smokenadoes" started coming into view.  In this shot its obvious we have some low scud being lit white because we are on the backside of the storm.  This junk would tease us for the rest of the chase.

 

 

The northern and southern cell both had tornado warnings now.  We stayed with our storm though, not wanting to abandon any potential that it had.  I noticed some white plumes rising off to the east and initially dismissed it as smoke.  The pictures from here on out would make a professional photographer squirm.  I learned the hard way to turn auto focus off when shooting video and now I know to do the same with stills.  This shot, while the best one I have of this ground level cloud, is focused on the rain drops on the windshield with the GPS reflecting as well.  Meanwhile, Bob hadn't charged the battery in his camera from a previous day of shooting and it was dead after the fifth shot.  This was not our day for pictures. 

The plume in the previous shot was making me suspicious.  Bob was sure it was smoke though and with this view to the east, noting the sparse puffs and horizontal leveling, I agreed with him.

The tornado warning on our storm expired, and it was looking more and more junky.  I made the call to abandon our intercept route and we retraced our steps for an intercept on the southern cell that had a confirmed tornado reported with it.  This outflow feature formed as we retreated.

Coming into the backside of the southern cell we noted the same white smoke again.  Because it was in a different location I knew that it had to be storm associated.  So the question remained, what is it?  Most likely ground level scud.  Jenny had seen two plumes twisting so we were discussing the potential of it being a gustnado.  Then, and only lasting for a few seconds, one of the plumes corkscrewed up like a dust devil.  This one crappy shot is all I managed to get off.  It's heavily contrast enhanced so you can actually see it.  There isn't much to go off of here but if anyone reading this log can provide some insight as to what this is I would be greatly obliged.  There did not appear to be any funnels, wall clouds, or other mesocyclonic structure for this "ghostnado" to be pendant to.

Quote of the trip:

"TORNADO!!! ...or is that smoke?"

Trying to keep up with our storm that had put down a tornado near Greece we finally got to the southern edge and this junky wall cloud came into view.  There was a little bit of a tail cloud to it but the whole thing looked rather disorganized.  Since this storm had already tornadoed I assumed it was weakening and we made plans to abandon it.  A plethora of law enforcement spotters were out zipping along the county roads with their lights on.  The trees and irregular road grid made observing this storm a headache.

The chase was quickly turning into a crapshoot junk-fest.  Our storms lost their tornado warnings and went to severe.  New cells were going tornadic to the east and we raced east on I-57 to I-70 to catch them.  Near Clark County we caught another lowering from the cloud base, another wall cloud probably.

We followed the storms and tornado warnings, always a step or two behind, across the Indiana border.  At about 8:00 or so the precipitation was increasing along with decreasing sunlight.  Jenny was driving and commented on feeling some "weird winds".  Right on cue a tornado warning went up for Vigo County with a Doppler radar indicated tornado eight miles southwest of West Terra Haute.  I checked the GPS for our current location.  We were 8 miles southwest of West Terra Haute.  I craned my neck around all the windows and saw absolutely nothing noteworthy other then increasing amounts of lightning.  If there was a tornado, visibility was so poor we weren't going to see it.  I was tired of chasing junk warnings so I called it a chase and we looked for a decent grub joint in Terra Haute settling on the Applebee's.  Sirens were going off somewhere in the distance and there were terrific amounts of CG now.
Nothing like blowing the chase off in mid tornado warning.  Our server informed us and the other tables of the warning just for public awareness.  Bob's content smile was just for show in this shot.

Well, I had managed to drag Bob and Jenny around for another several hundred miles without a tornado.  If only we had gone to Kansas the day before (then we could have busted with over a thousand miles).

Conclusion:

This was a frustrating chase and a bust.  We didn't get isolated supercells but severe complexes filled with low hanging junk.  The severe hail did not make up for 500 miles of some of the ugliest storms I have ever seen.  I can only imagine what it would have been like without the GPS, blindly taking county roads in hopes that they lead where we want to go.  The catches of the day were a classic tornado that Chris Novy caught in Woodford County and a dusk tornado near Indianapolis that had a more violent appearance.

 

Lessons learned:
  • Secure your cargo pods better, and don't use them if you don't have to.
  • Near Vandalia and further south the chase territory gets ugly.

yowzers