March 1, 2007

Statistics:

Initial Target: Edwardsville, IL
Departure: Peoria, IL 6:30 am CDT
Arrival: Bolingbrook, IL 6:30 pm CDT
Intercepts: Gillespie, IL and Clay City, IL
Tornadoes: 0
Hail: Non-Severe (pea sized)
Wind: Non-Severe (not measured)
Features: Gust Front
Miles: 694

Summary:

Chased Moderate Risk portion of High Risk, low cape high shear setup.  Targeted Edwardsville at 18z.  Left Peoria at 6:30 am, intercepting severe warned cell near Gillespie IL at 9:30 am.  Cell was rapidly deteriorating, so abandoned it and headed east on 70.  Met up with Scott Weberpal in Vandalia.  Squall line initiated in west central IL.  Kept ahead of it on I-70, before caravanning with Mark Sefried and Andrew Pritchard to Clay City where we watched a gust front roll overhead.  Called the chase a bust at 2:30 pm and headed home.

Crew and Equipment:

Solo chase. Equipment consisted of a TH-F6A Tribander, and GPS/Cell Phone equipped laptop.  Photography by Skip Talbot.

Details:

I'm still a sucker for SPC's forecasts, and I was suckered into this one.  The setup was primed for a tornado outbreak, but in the southern states.  Further north in Illinois, there was also a chance for severe weather and tornadoes, but instability was forecast to be much lower.  The forecasted 979 mb low over the Quad Cities was amazing though.  Initially only a Slight Risk on the Day 3 forecast, I wasn't planning on chasing this.  When the Day 2 upgraded IL to a 45% hatched Moderate Risk, I decided to call in sick to work.

Tornadic supercells were forecast to fire overnight in Kansas and Missouri, and continue their trek through the night, crossing the Mississippi before noon the next day.  It appeared that the left over morning junk was going to be the action for this chase, so I made plans to target Edwardsville, and be there bright and early.  Instead of leaving at 4 or 5 in the morning, I met my storm loathing friend, Kristen Miller, at her apartment in Peoria, and spent the night there.  I stayed up for the Day 1 and was dismayed to see that SPC had indeed upgraded to a high risk, but not for Illinois, and the tornado probabilities only made it up to 5% in southern IL.  Perhaps I shouldn't have called in sick.  Mark Sefried wanted to form a caravan before 6 the next morning, but my alarm failed to sound and he was on the road before I got up.  I sluggishly got on the road by 6:30, briefly getting caught in a line of storms with heavy rain and lightning.  I was able to escape the northeast moving line, running south on 155. 

Several supercells were tornado warned in Missouri when I left, but they were downgraded to severe or not warned by the time I was on the scene.  I intercepted a severe warned cell near Gillespie, IL.  The radar still showed a meso on the cell, but it looked grotesquely stretched.  The base of the storm was elevated and disorganized.  I watched it fall apart for a few minutes, before I decided to get back out ahead of the line in case something else flared up to the south.
Stopping in Vandalia for some grub, I met up with Scott Weberpal.  A line of cu was developing to the west, and we were in prime position to intercept when it went up.  A rather solid, and linear looking line flared up before noon, and we held our ground, not wanting to prematurely intercept a line moving 50 mph.

Scott left to intercept the southern most cell, Tail-End-Charlie, but I wasn't sold and hung around Vandalia.  When the line started closing in on me I got on 70 and headed east to keep ahead of it.  I was hoping that development to the south would turn supercellular or that there would be a break in the line, from which I could intercept a base.

I met up with Mark Sefried and Andrew Pritchard in Alton.  We caravanned southeast from there.  We stopped to shoot what appeared to be a base but was just the gust front: pictured right, looking southwest.

The line caught us just north of Clay City and we got blasted by the core for a few minutes with pea sized hail.  We outran it, amazingly, and got on the southern end to see if we could spot a base.  A wall cloud wannabe under the gust front, looking northwest:
Huge flocks of birds were trying to outrun the storm and we were getting swarmed from all directions.  The birds were flying quite low and straight at us.  It was a remake of an Alfred Hitchcock movie.
The gust front looking north:
Looking southwest:
Looking south as the gust front passed overhead, with minimal precipitation, and a bit of a whale's mouth type feature.
It was obvious that we were chasing a weakening, linear squall line.  SPC had a discussion out saying that CAPE would build to the east and that there was still a tornado probability.  However, this area was socked in with precip so it was clear there wouldn't be any destabilization.  We called the chase a bust at 2:30.  Looking southeast on the back end of the squall line as we headed back:
Mark, Andrew and I caravanned up to Effingham where we were going to stop for some pizza, but we couldn't find any good pizzerias so we all split up and headed home.
Conclusion:

This was a rather disappointing chase seeing how the setup was hyped so much.  The entire day was a loss it turned out, with the Illinois storms being linear junk (with the exception of a briefly tornado warned cell near Peoria), and the supercells to the south being unchaseable and deadly.

 

Lessons Learned:

  • Don't be suckered into taking off work to chase a squall line.