March 10, 2009

Statistics:

Initial Target: Litchfield, IL
Departure: Naperville, IL 11:30 am
Arrival: Westchester, IL 9:00 pm
Intercepts: None
Tornadoes: 0
Hail: None
Wind: Non-Severe (not measured)
Features: None
Miles: 521

Summary:

Chased low instability, highly sheared cold front setup in central IL, targeting Litchfield, IL.  Rendezvoused with Jesse Risley, Mike Brady, and Randy Cooper at 4 pm.  Followed weak cell to Vandalia, IL before it evaporated.  Called chase a bust at 5:30 pm due to excessive cloud cover in the warm sector and precipitation on the cold front preventing discrete cell formation.

Crew and Equipment:

Solo Chase.  Equipment: TH-F6A Tribander, and GPS/mobile data card equipped laptop.

Details:

After a not so great chase two days earlier, I was up for another shot.  A deepening system was forecast to move up through IL bring with it 60 degree dewpoints, a morning MCS on the warm front, and a cold front that was to be the focus for afternoon thunderstorms.  I left work at 11:30 am targeting Litchfield, IL.  The low level cape was forecast to be the highest here at 21z despite overall mediocre instability of the setup (500 J/Kg Suface Based).  Shear was strong, but had good low level veering.  The plan was to catch discrete mini supercells coming off the cold front before a linear line formed early in the evening.
The morning MCS was expansive and restricted the northern extent of the warm sector.  Although there was some clearing along the I-70 corridor, substanital cloud cover limited instability across the region.  The cloud breaks with 75 degree temperatures near St. Louis were enough to keep me going to my target.  I headed down 55 south and rendezvoused with Jesse Risley, Mike Brady, and Randy Cooper in Litchfield, IL.  We checked the data and noticed a small cell starting to go up our southwest.  We followed 185 down to Vandalia to intercept it, but it evaporated before we even got to it.  The cold front had filled in with precipitation, with any prefrontal initation quickly failing in the seemingly capped atmosphere.  We all waited until the cold front with its mediocre band of rain approached our location.  I called it a bust at 5:30 and headed for home up 57.  Jesse and crew headed back to 55 and had a little fun with a cell that briefly organized on the cold front. 
 
Conclusion:

I had low expectations for this setup given the marginal conditions.  In the end it was a complete bust.  Only a few severe warnings were issued and no reports came in.  It was fun meeting up with Jesse, Mike, and Randy, however, and it was also nice to feel 75 degree temperatures in March.

 

Lessons Learned:

  • Cloud cover and frontal precip can ruin a marginal setup.