March 12, 2006

Statistics:

Initial Target: Jacksonville, IL
Departure: Westmont, IL 11:00 am CDT
Arrival: Bolingbrook, IL 1:30 am CDT
Intercepts: Mexico, MO; Jacksonville, IL
Tornadoes: 1
Hail: None
Wind: Non-Severe (not measured)
Features: Tornado, RFD Clear Slot, Wall Cloud
Miles: 580.0

Summary:

Got out from work at 11am met up with Dan Cook and met Fabian Guerra at Cass Ave. and I-55.  Targeted Quincy, IL since it was on the forecasted warm front position and east of MS river.  Warm front failed to initiate so blasted into MO after mature dryline storms in central MO.  Intercepted tornado warned storm near Mexico, MO and observed precip shrouded wall cloud.  Dropped to southern storm and observed occluded base with an RFD clear slot and rotating fractus.  Tracked storm until darkness and road network prevented us from pursuing.  Caught storm again on I-72 near Jacksonville IL, observing large tornado between lightning flashes.  Observed power flashes as tornado entered Springfield.  Pursued on Highway 56, but debris, high winds, and loss of situational awareness brought the chase to an end.

Crew and Equipment:

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

Details:

This setup went unnoticed by me for a long time.  I was so engrossed in Saturday's setup (March 11) that I failed to check further out on the models.  When I finally did, I nearly forgot about Saturday.  A sharp warm front was to set up across central IL, destabilizing the atmosphere to 2000 J/kg.  Coupled with 1km SRH values over 300, it screamed tornado outbreak.  Forecasted Significant Tornado values on the 0z NAM run the night before were over 10.  Sure enough, SPC went with a high risk and a 30% tornado forecast.  The highest I had seen since May 10, 2003.
I met Dan outside my work and Fabian at the park near Argonne lab.  We targeted Quincy IL, since it on the best shear and instability combination east of the of the MS.  The models had turned out to be a little too fast in moving this system so the triple point wound up in western MO.  There were two areas of development being monitored.  The dryline, extending from northwest MO to southeast KS, and the warm front across northern MO dipping down into southern IL.  The dryline was too far, and we did not want to chase Missouri's terrible terrain, so we waited for the warm front to move north across IL.

Traveling south on 55 and then west on 72 we thought about stopping at the Jacksonville data stop.  I called out on the ham radio, but got no reply, and thus decided we better press on to our target area.  It turns out the chaser convergence had indeed landed there, but everyone must have been out of their cars.

Arriving in Quincy, it was misting, grey, and cool.  The warm front was nowhere near us and it was obvious our positioning was off.  Quincy is also a chaser trap.  There is one main route into town and it takes you more than 20 miles off I-72, forcing you to go back the way you came.  The town itself is too large and congested to make a quick gas and data stop.  Quincy will be avoided in future chases.

Our warm front was not moving as far north as we hoped, and showed no sign of initiation.  Storms had fired early, as expected across the dryline, and were now mature supercells as they moved across Missouri.  This looked like the only show of the day, so the decision was made to bite the bullet and head into Misery, I mean Missouri, for the intercept.  Several storms were tornado warned exhibiting nice hooks, so we pushed the Shibster envelope hoping to make it there in time.  We raced east on highway 36 through Hannibal and then south on 24 to 107.  The weather radio was sounding warnings for storms capable of producing tornadoes and baseball sized.  We could see the line of supercells moving in on us from the west and it soon became a race not to get cored. 

Finally arriving in Mexico, the terrain actually opened up for us in a few spots.  The anvil from our tornado warned storm loomed overhead with faint mammatus.  On the south side of town we stopped at a hotel to get data.  The hotel's wifi was locked but we were able to get our cell phone connection back.  We thought we had intercepted Tail End Charlie, but we soon discovered the dominant storm was still to the south.  The base of the storm we intercepted came into view with a ragged wall cloud hanging underneath.  It was low to the ground but heavily obscured by the storm's precip core.  The precip from the Tail End Charlie storm was starting to overtake us as well.  I opted to move south to the other storm, but Fabian and Dan were reluctant to abandon the wall cloud.  If we stayed we'd have to walk a fine line between getting cored by the southern storm or putting ourselves under a tornado warned, rain wrapped wall cloud.

South we went, leaving the major highways that went through Mexico for the rural county roads.  We clipped the southern storm's precip core and came out right under the rear flanking downdraft clear slot.  The base had already occluded, the gaping hole where the RFD had punched through was quiet.  The storm had already travel more than half way across Missouri, tornado warned, recycling its updraft several times along the way.  I pointed out that, although the base occluded, this storm had an unobstructed inflow of warm, moist air, the jet was continuing to nose into the area, and that this supercell would probably remain cyclical for awhile (indeed it remained cyclical for longer than I could have imagined).  The fractus beneath the forward flank of the rain free base was rotating directly in front of us, making us all a little uneasy.  We pursued the storm as best we could through the hills, trees, and sparse maze of roads that make up east central Missouri, but we were never able to position ourselves as well as our initial intercept.

The rain free base continued to extend out from the southward progressing precipitation core.  Lowering in the core itself looked suspicious, but we were unable to get close enough to investigate.  Out of the corner of my eye I saw a ragged tube of dust or condensation rise up from the ground on the southern end of the RFB.  I prematurely shouted "tornado!" and the feature quickly dissolved before it could be verified.  It was most likely just fractus (scud) created by sharp rising motion near the surface, similar to what I had seen May 30, 2004.  It could have also been a brief gustnado or spout, but we'll never know.

Dusk set in and our storm was pulling away from us.  We had seen only a few ragged lowerings that may or may not have been wall clouds.  Our road network finally went to crap, giving us an east-southeast only option and the storm pulled away to the northeast.  Darkness set in and our hopes were sinking.  With no data, no visibility in the dark, and expecting the storms to be dieing at this hour I finally conceded to Dan and Fabian that our chase was over.  They agreed and we plotted a route for home.

We stopped for gas in Louisiana, MO, right on the river.  Fabian, got our data back and fired up the radar.  We were all taken aback by one of the most glorious radar signatures I had ever seen.  The storm had a huge hook on it.  Fabian was quick to point out that the storm was only about 40 miles away, and we'd soon be on 72 with a clear shot at catching the hook as it crossed the interstate.  The following images were screen shots from GRLevel3 we took during the chase, the Shibster icon was our GPS location.

 

 

We worked our way up 54 and then blasted east on 72.  The interstate was nearly deserted.  A full moon and stars shown above us and actually illuminated the storms top as we approached.  A silver knuckled anvil beneath a starry sky.  Frequent anvil crawlers shout out from the tower.  It was a beautiful sight and we were all in awe taking it in.  The monotone computer voice on the weather radio cut out from its continuous droning loop of tornado warnings.  One of the forecasters from Lincoln went on the radio live, something I've never heard before.  "Spotters are tracking a large tornado approaching Manchester." 

 

I buried the needle on the speedometer and we quickly approached the base of the storm.  CG was flashing from multiple locations in front of us illuminating the rain free base.  There was a flash of lightning to our southeast, briefly illuminating a dark column shaped figure on the horizon.  Fabian and I both started to mumble, "Is that a...", "What is th-".  Our eyes were all trained on the spot now.  Lightning flashed again and the barrel shaped tornado was obvious.  We all shouted in disbelief.
 

We spotted the tornado at approximately 7:55 as it passed Murrayville.  The tornado was about 15 miles to our southeast, but an unobstructed view allowed lightning to silhouette the distant figure for us.  The map above indicates our GPS trail (green) and our position upon spotting the tornado (red  square).  The dashed line was our viewing angle and direction.  The red diagonal in the lower right corner represents tornado's path with the red square is the tornado's position upon our sighting.

We got four or five more flashes of lightning that illuminated the funnel.  The tornado narrowed into a stovepipe, before it finally stretched out parallel to the storms base, bending back towards the ground.  It was roping out, and we lost sight of it, but we didn't doubt that it was still there or that this storm was nowhere near done.  We slowed down to match the storm's speed, not wanting to run into the vortex as it crossed the interstate.

 

Bright green bursts of light flared up straight ahead.  The power flashes indicated that the tornado was indeed still on the ground, and was entering Springfield.  We proceeded with extreme caution now, expecting to encounter debris in the road.
This radar grab is not entirely accurate.  The scan was already about 5 minutes old, so the storm had advanced, and we were not directly in the hook.  I had  Fabian grab a capture of it anyway just for dramatic effect.

What would later be rated an F2 tornado with a 60 mile path length, was now midway through Springfield.  All the signs along the highway had been blown over and there were several cars in the ditch.

 

We lost our data connection again but we continued the chase, hoping to cautiously follow the storm behind its hook.  I-72 merged with I-55 and we exited to stay on 72.  The on ramp was backed up, the traffic at a stand still.  We later learned that it was downed power lines blocking the road, but further up our chaser friend Stan Olson met catastrophe.  The tornado rolled a silo into the highway and he struck it, unable to stop in time.  His airbags went off and the front end of the car sustained damage, but Stan wasn't hurt.  Click here for pictures and Stan's chase log.

We turned around and instead exited on highway 54.  The road was filled with branches, leaves, and other small debris.  The highway nearly paralleled the storm's motion.  The debris and our lack of data was making the situation progressively more dangerous.  The weather radio came on with another live report which put the tornado a few miles to our south.  "Stop!" exclaimed Fabian.  If we continued up the road we might inadvertently drive directly into the tornado.  If the tornado was actually behind we might do the same by turning around.  We stopped for an emergency assessment of our situation.  Unbeknownst to me, a car filled with locals had leeched on to us.  They pulled up and started asking us questions, but we ignored them, far too busy trying to plot an escape route.  They pulled up ahead of us and waited.  Then the winds hit.  out of the north-northwest, howling.  Dust and small debris flew across the road and the car rocked.  We all nearly panicked at this point and I felt sick to my stomach knowing that there was a large tornado somewhere in the darkness and we were sitting blind.  When the winds died, I jumped out of the car and scanned the skies as best I could to get a bearing for where in relation to the storm, but it was too dark.  The winds abruptly changed directions to the south, further adding to our unsettling feeling.  I ran up to the other car.  Judging by their lack of radio and other equipment, these guys were not chasers, but I asked them if they were anyway.  "No," they said, "but we're gonna be tonight!."  I proceeded to tell them that the weather radio was reporting a half mile wide tornado about a mile up the road, and that it was impossible to see.  I also told them that we were getting the hell out of there and strongly encouraged them to do the same.  They stared at my weather spotter shirt silently for a few moments.  "I hope you guys make the right decision," I said and then jogged back to the car.  While Fabian and I finalized our escape route, the car of locals turned around and headed away from the storm.

 

 

 

It later turned out that we were further from the tornado than we thought, lagging behind it by about 12 miles.  After having the crap nearly scared out of us, we left our storm, still spinning a large hook, and called it a chase.  Traveling up 55 we could still see storms off to our right.  After what we had seen tonight our eyes were playing tricks on us and we kept spotting wall clouds underneath the distant bases.  Dan and I caught the severe line that was ravaging northern IL on the way back to his house.  It was dieing out at this point and greeted us only with a light show and copious amounts of rain.  I pulled the Shibster into the garage after 1, exhausted and knowing I'd have to be up in a few hours for work.
Conclusion:

This chase went from bust, to boom, to panic filled terror.  It was a wild night.  The chase was a bust in terms of capturing it on film.  While driving I was unable to shoot stills, and Dan's video did not turn out.  Even more depressing, it turns out my video camera was in stand by mode during the tornado.

Amazingly, our supercell had formed in southeastern Kansas and maintained supercellular characteristics all the way to Michigan.  Never before had I seen a storm with such a long path length.  140 tornado reports came in, most in Missouri, including an F4.  The high risk verified big time and this weekend turned out to be a huge start to the chase season.  I had nearly topped my entire 2005 chase season before the date of my first 2005 chase.

 

 

Lessons Learned:

  • When you see a tornado, take a deep breath, and make sure you are actually recording it.
  • Abandon a nocturnal chase the moment you lose situational awareness.