Target Area: Hobart, Oklahoma (Click on city names for Yahoo! maps links)
Observations: two supercells, lightning, a rainbow, and an amazing sunset with mammatus clouds
Distance: 430 miles
Time: 11 hours
Chase Team: Car 1 - Jeff Makowski and myself; Car 2 - Hin Pang, Toby, and Jun
SPC Convective Outlook: Moderate Risk (upgraded to High) (Click to see SPC products, data, and storm reports)
Chase Setup: A surface low set up over the Texas Panhandle while a warm front lifted up through central Oklahoma and a dryline tightened along the Texas Panhandle / Oklahoma border. Dewpoints ahead of the dryline were in the low to mid-60s. A trough over the High Plains into the Central Plains provided lift for storms to develop along the dryline, near the low, and along the warm front. MLCAPE reached 1500 to 2000 J kg-1 in central into southern Oklahoma ahead of the dryline, with not much of a cap. East/southeast surface winds veered to southwest aloft, providing wind shear for supercells (bulk shear was around 50 knots and effective SRH was between 500 and 600 m2 s-2 in northeast / east central Oklahoma). Initiation was expected to be early and outflow boundaries put down by the overnight MCS were expected to contribute to the setup.
Chase #9 (before)
High Risk (during)
Chase Log: We met up with Hin and two of his friends from England this day; Hin was part of the first group that I went chasing with in spring 2007, and he decided to come back for a couple of weeks this spring.
My initial target was somewhere between Clinton and Lawton; although the warm front was the target that was the most certain to verify, we opted to stay farther south, to avoid the chaser zoo and the mess of storms that would quickly congeal.
No sooner did we head out than the SPC issued yet another high risk for central Oklahoma, prompting fears that what happened on May 10th (several strong tornadoes in populated areas) would happen this day.
We first drove to Hobart, where we sat for a while at a Sonic, watching towering cumulus clouds. Eventually we pulled the trigger and headed north up to I-40, towards some quickly growing cumulus congestus. Heading east on I-40, we saw at least one or two large supercells in the distance to our north. Soon afterwards, we saw some cumulonimbus clouds to our south. After the usual tough decision as to whether to go north or south, we leaned towards our original target area and dropped south again at Hinton.
Once we got to Anadarko, we saw a nice towering cumulus congestus that we decided to go after. Just outside of Chickasha, we stopped to watch the fastest growing convection I have ever seen. The pure white, beautiful, towering cumulus grew up and up and anvilled out before our eyes.
Needing to gas up, we went back through Chickasha and stopped at a gas station, where a guy asked me if I was from around there. Not sure why he was wondering, I said not exactly, though I came from central Oklahoma. He pointed at a paper map and told me that he wanted to know how to get out of there and towards Purcell. I gave him directions and he rushed off, saying something to the effect of a tornado warning was just issued on the nearby storm, headed for Norman!
We followed his lead, and drove east towards Purcell. We stopped a couple of times as we caught glimpses of rotation, and possibly a wall cloud, within some rain. Several miles west of Purcell, we stopped for a while to watch the supercell, while we also kept an eye on the supercell not far to our south.
KSBI called me to tell me the southern storm had gone tornadic and they did not have anyone to cover it, so after a few more minutes to make sure the storm we were on was not going to turn tornadic and hit Norman (as on May 10th), we continued on to Purcell and drove south on I-35.
Just before we got to Pauls Valley, we took an exit and drove northwest a bit to Maysville, as we were afraid of driving into the core of a tornadic storm that was sitting over the freeway. Although we may have had the chance to catch a tornado or two on this southern storm, we instead opted to remain north/northwest of it and photograph an amazing sunset amidst cumulus and mammatus clouds, and afterwards a great lightning show.
After watching the lightning for a while, we drove back home. Although we missed tornadoes that many other chasers saw this day, we avoided the chaser zoo up north and had the pleasure of seeing some amazing convection, lightning, and a gorgeous sunset, all close to home! It was all in all a great day.