Target Area: Shamrock, Texas (Click on city names for Yahoo! maps links)
Observations: three supercells, hail, and lightning
Distance: 540 miles
Time: 11 hours
Chase Team: Car 1 - Dean Narramore, Esther White, Amy Edmonds, and myself; Car 2 - Rob Warren, Rob Lee, Rob Graham, Pete Argyle, Becky Hewins, and David Sherman
SPC Convective Outlook: Moderate Risk (Click to see SPC products, data, and storm reports)
Chase Setup: Shortwave trough over the Great Basin and a cold front stretched from central Kansas through northwest Oklahoma into the central Texas Panhandle. Dryline situated just in front of the cold front in the Texas Panhandle. Moderate instability in west central Oklahoma and moderate to strong vertical wind shear in northwest Oklahoma. Dewpoints in the lower 60s in the east Texas Panhandle, Oklahoma, and southwest Kansas (just south of a surface low). Supercells expected to form along the dryline in Texas and all along the cold front up into Kansas. Primary threat in Oklahoma expected to be large hail, although a few tornadoes expected along the Texas/Oklahoma border, especially around the intersection of the cold front and dryline.
Chase Log: I was pretty optimistic about the chance to see supercells and possibly tornadoes on this day, probably somewhere around northwest Oklahoma where the shear was greatest or the Oklahoma/Texas Panhandle border at the intersection of the dryline and cold front. The following day's setup looked even better, though, so I felt pretty confident that we would see some good storms on at least one, if not both days.
We started out by driving to Shamrock, where we ran into many other storm chasers hanging out at the Best Western and the gas station across the street. After a brief stop and a look at the latest observations, we headed north along the Texas/Oklahoma border to chase a nice-looking storm.
After some deliberation as to whether or not to continue following the storm once it started to look like it wouldn't rotate enough for our liking, we eventually crossed the Oklahoma border and chased the storm to Leedey. We stopped for a while, watching the supercell, hoping it would get its act together. After teasing us by an apparent wall cloud beginning to form, the outflow-dominant storm moved to our northeast and we decided to let it go around sunset.
On our drive back, we stopped at a Love's gas station in Clinton as a squall line had formed along the cold front and was about to overtake us. In our area the squall line had radar-indicated hail of about 2 inches, so I parked my car squarely under the middle of the large roof over the gas pumps. As soon as I finished filling up my car, the hail started to fall and nearby cars crowded under the roof. We started to collect hail, trying to find the largest stones. Most of the hailstones were about 1 to 1.5 inches in diameter, but I measured the largest stone at 2 inches! It was a fun chase, and left us all looking forward to the next day, which turned out to be even better.