November 22, 2010


Initial Target: Dekalb, IL
Departure: Westchester, IL 2:00 pm CDT
Arrival: Westchester, IL 4:30 pm CDT
Intercepts: Waterman, IL
Tornadoes: 0
Hail: Severe (1 inch estimated)
Wind: Non-Severe (not measured)
Features: Wall Cloud
Miles: 134


High shear/low cape/unidirectional setup in IL. Left at 2pm and intercepted discrete severe warned cells moving northwest towards Dekalb near Waterman, IL. Noted RFD core and developing wall cloud as storm went tornado warned. Encountered 1 inch hail trying to keep up with storm. Wall cloud became heavily rain wrapped and fast storm speeds and suburban terrain brought an end to the chase. Made it home by 4:30 in the rain following storms back to Westchester.

Crew and Equipment:

Solo chase.  Equipment:  Kenwood TH-F6A Tribander, Dell Inspiron Laptop.  Kyocera data card and router, Holux 236 GPS, Robotic camera dome with Sony XR-520V.




Monday's setup was a high shear/low cape day featuring mostly unidirectional winds and a sharp cold front. A mostly linear event was expected as a result. With a 90 knot mid level jet and 60 knot low level jet, and veering with height ahead of the front, the potential for some supercells/tornadoes did exist on storms that could stay discrete or last ahead of the front. I wasn't too optimistic about the chase opportunities on this day, but after storms fired on the MS during the morning hours and stayed discrete until early afternoon I decided to bite and left at 2 pm down 88 west.

A line of cells was tracking from southern MO into southern WI. The winds were backed most up in Wisconsin, but after not committing to the chase until the last moment, my only play was with cells closer to home coming up towards the Dekalb area. The plan was to head west on 88 and intercept as they approached the highway. I wound up heading south on highway 23 and catching a severe warned cell near Waterman, IL. The storm looked HP-ish, grey, and grungy, and outflow dominant. I hold with it like an action RPG player, however as its appearance was improving on radar and it looked like the best storm in the area.

I tried my best to pursue the storm that was moving NE at 45 on some gravel roads. Along the way I bumped into chaser Matt Cumberland and we teamed up for the rest of the chase. Attempting to stay in what should have been the rain free inflow notch, we hit some severe hail and had to keep moving east and north to keep up with the storm not having time to stop. The hook on the radar tightened up and a wall cloud started to develop on the northern end of the RFD core just as the storm went tornado warned. Now the chase was on!
We did our best zig zagging along some gravel and paved county roads trying to keep up with the storm. The wall cloud lasted for a few minutes and had a tail cloud on it, but it soon became heavily rain wrapped as cells to the south encroached and congealed into one solid line. Taking a tight turn my GPS got flung on the floor and I lost navigation. I didn't have time to stop and fix it, so I did my best to try and guess where I was on the map and which direction I was headed. I eventually wound up on 47 where the roads diverge and the suburbs begin, and the storm was pulling away with no visual left.

With the storms deteriorating, and the favorable Illinois terrain giving away to the built up suburbs, Matt and I called it a chase and split up. Heading back onto 88 to head home I wound up right behind Adam Lucio. I always find it amusing how I always bump into the same people while out chasing as paths cross with people from all over. I made it home by 4:30 after driving home in the rain in heavy traffic.



This was a fun backyard chase. At 134 miles it was also the shortest chase of the year for me. Given the marginal instability and unidirectional wind profile I had rather low expectations going into this chase. Catching a tornado warned supercell and wall cloud close to home was a nice treat on a short notice chase though, so I won't count this one as a bust. It was also nice meeting up with Matt Cumberland again and bumping into Adam Lucio on the way home. There was a signifiant tornado up by Loves Park, IL that I heard about on the way home. The better directional shear to the north and better separation between storms probably enhanced the tornado threat up there. I knew tornadoes would be isolated and that it was a crap shoot trying to pick the right cell given the short notice, so I don't feel bad about missing any of the action.


Lessons Learned: 

  • Tape the GPS to the dash so it doesn't come flying off during a turn.