Green Sky Chaser

1 June 2010 Chase Log


Target Area: Beatrice/York/Lincoln, Nebraska

Chase Area: York/Columbus/Chester, Nebraska

Observations: four to six funnel clouds, about four wall clouds, at least one supercell, squall line, at least two gustnadoes, lightning, and a green sky

Distance: 585 miles

Time: 13 hours

Chase Team: Dean Narramore, Willoughby Owen, Rob Warren, Rob Lee, and myself

SPC Convective Outlook: Slight Risk (upgraded to Moderate) (Click to see SPC products, data, and storm reports)

Chase Setup: An upper-level trough was situated over Ontario while several embedded shortwaves were found within the generally zonal flow over much of the rest of the U.S. One subtle shortwave was found in eastern Nebraska, where 500 mb winds were at a local max of 50 knots. A surface low was located in eastern South Dakota, while a cold front trailed to the southwest. Dewpoints ahead of the front were in the 60s. MLCAPE was maximized at 2000 to 3000 J kg-1 in southern Nebraska (especially south central). Mid-level lapse rates were maximized at 8 to 8.5 °C km-1 in southeastern Nebraska (excluding the max in western Kansas and Colorado). Wind profiles in southeastern Nebraska veered nicely as well, where effective SRH was 300 to 400 m2 s-2. Supercells were expected to form early along and ahead of the front, but were expected to quickly merge into a squall line as the cold front caught up to them.

Chase Log: We started off the day in Hays, Kansas, and drove up towards towards southeast Nebraska. We stopped for a little while in York, Nebraska, to wait for initiation and hang out with some friends on the VORTEX2 crew.

After we saw some storms go up to our north, we drove up to Silver Creek, where we intercepted a tornado-warned supercell and caught a brief glimpse of a wall cloud before it shrunk and became enshrouded in rain. This was the closest we came to intercepting something isolated; from here on out, the storms began to rapidly increase in number and merge into a squall line.

A little ways south of Silver Creek, we saw a brief gustnado as the storms began to close in on us. We also saw a couple of other wall clouds on the storms in this area.

After trying to navigate in and out of the squall line for a while, we realized that we were probably not going to see anything severe and decided to call it a day and head back south. Down near the Kansas border, just outside of Chester, Nebraska, we saw another gustnado that was briefly multi-vortex. We stopped to get some photos of the gustnado, as well as of the sunset and squall line, near an old abandoned house in the middle of a wheat field.

We spent the night in Wichita and drove back to Norman the next day.