Dan Robinson
EF5
The warm front in central Illinois had been on my radar for the the past day, but I didn't call off of work to chase due to the fact that short-term models had the cap squashing any storms by early afternoon. However, by mid-morning, the models flipped and started showing storms persisting along the boundary for the duration of the evening. This was not a situation to ignore, so I left work at noon and made the trek north to Bloomington-Normal.
The obvious storm of the day initiated west of Peoria and strengthened as it approached Bloomington with frequent lightning. However, it was cold and outflow-dominant. Thinking that it may get its act together as it encountered the boundary, I stayed with it. This was not a leisurely task, as the storm was moving at a good clip - I could not stop for more than a minute at any given location. Finally, as the storm crossed Interstate 55, it began gaining supercell characteristics both visually and on radar.
There was no surface-based inflow, however, as forward-flank outflow and the RFD continually undercut the inflow notch. This continued for the rest of the chase, and I did not note any low-level inflow making into the storm - everything was constantly being undercut by northerly winds blasting out of the core. Nonetheless, the storm had some mean-looking structure as it tracked southeast, along with a broad circulation and beefy hook echo on radar:
With fading daylight, work at 5:30AM the next morning and another big chase day to follow on Saturday, I broke off of the storm at Danville, IL and started the 3-hour drive home.
The obvious storm of the day initiated west of Peoria and strengthened as it approached Bloomington with frequent lightning. However, it was cold and outflow-dominant. Thinking that it may get its act together as it encountered the boundary, I stayed with it. This was not a leisurely task, as the storm was moving at a good clip - I could not stop for more than a minute at any given location. Finally, as the storm crossed Interstate 55, it began gaining supercell characteristics both visually and on radar.
There was no surface-based inflow, however, as forward-flank outflow and the RFD continually undercut the inflow notch. This continued for the rest of the chase, and I did not note any low-level inflow making into the storm - everything was constantly being undercut by northerly winds blasting out of the core. Nonetheless, the storm had some mean-looking structure as it tracked southeast, along with a broad circulation and beefy hook echo on radar:
![may2617a.jpg may2617a.jpg](https://stormtrack.org/data/attachments/17/17501-ac3d859b47e016b88283fddaf2b9128b.jpg)
![may2617b.jpg may2617b.jpg](https://stormtrack.org/data/attachments/17/17502-2241a4f50a817fe1289738db70b9f135.jpg)
![may2617c.jpg may2617c.jpg](https://stormtrack.org/data/attachments/17/17503-838723f658818da615d4e62b3537376f.jpg)
With fading daylight, work at 5:30AM the next morning and another big chase day to follow on Saturday, I broke off of the storm at Danville, IL and started the 3-hour drive home.