Target Area: Sioux Falls, South Dakota(Click on city names for Yahoo! maps links)
Observations: two or three wall clouds, at least one supercell, squall line, hail, lightning, three deer, and more fireflies
Distance: 545 miles
Time: 14.5 hours
Chase Team: Jeff Makowski and myself
SPC Convective Outlook: Slight Risk (upgraded to Moderate) (Click to see SPC products, data, and storm reports)
Chase Setup: A positively tilted shortwave trough was situated over eastern Montana and eastern Wyoming. A surface low was positioned in northeast Nebraska with a warm front extending to the east across northern Iowa. Winds in the vicinity of the warm front were from the east and southeast. Dewpoints were in the low 70s over northern Iowa, southern Minnesota, and eastern South Dakota. MLCAPE ranged from 2000 to 3000 J kg-1 in far southeast South Dakota, northeast Nebraska, and southwest Minnesota. 0 to 6 km bulk shear was around 40 knots in southeast South Dakota, while effective SRH was as high as 400 m2 s-2 in southwest Minnesota.
Chase Log: In the morning, we left from Sioux City, Iowa for Sioux Falls, South Dakota. After deliberating on whether or not to head out after some early storms, we drove north to Bruce, where we intercepted a storm that weakened just as we arrived (although a local radio station would have you believe that it was the best storm ever).
We then drove south again, but this time the storms were once again quickly lining out. We kept trying to get on the tail-end Charlie, and we did intercept a supercell with a couple of wall clouds near Freeman. However, the storms kept building to the south and we finally just got out ahead of the line in an effort to experience some hail.
In Beresford, we stopped at a car wash and waited for the line. Most of the hail that fell was dime- and penny-sized, but some of the hail was quarter-sized.
We followed the line into Iowa, but then gave up and spent the night in Council Bluffs.