Tuesday, May 10, 2011

February and April Storm Chases


February 27, 2011: Northern Oklahoma

I left Norman, OK just in time to intercept a supercell during the late afternoon, which moved east across I-35 near Blackwell, OK just as I arrived on the scene. The storm was low-topped, but showed signs of midlevel updraft rotation. A ragged wall cloud was present as well, but had a cold/stable look to it as I followed east along highway 11. However, as the storm moved over Newkirk, OK, the wall cloud become more organized, and low-level rotation steadily increased. It appeared that the area of rotation was contracting east of Newkirk, with cascading motion observed adjacent to the clear slot. By this point, a caravan of chasers (myself included) had to navigate muddy roads in order to keep up with the storm. The mud roads, in addition to the setting sun, and an apparent weakening in low-level rotation, led me to give up on the storm. I noticed the SPC storm reports page has two tornado reports near the KS/OK border occurring shortly after 00Z...perhaps I gave up too soon.




April 14, 2011: Eastern Oklahoma

My girlfriend Elizabeth Lyon and myself left Norman by mid-afternoon, and drove east down I-240 which hooked up with I-40. A storm developed immediately to our south, and quickly evolved into a supercell as we stopped near Shawnee, OK for pictures. We were hit by dime to quarter size hail as the forward flank downdraft brushed past our location. The storm had a large rain free base, which eventually began to suck in scud, leading to wall cloud development as we drove east away from Shawnee. The most interesting part of the storm moved north of the interstate as we reached the intersection of I-40 and highway 56. We followed highway 56 north-northeast, and then drove north on highway 48. We soon re-intercepted the updraft base, which began to go through a low-level mesocyclone occlusion. Tornadogenesis appeared to be minutes away from happening, but after 5 minutes of intense low-level rotation, the mesocyclone dissipated. We gave up on this storm and drove back south-southeast to intercept another storm merging with our northern cell. This storm developed an interesting area of low-level rotation, but was soon replaced by a cold/stable look in the low-levels accompanied by minimal rotation. We gave up on the chase soon after, and made the relatively quick hour long drive back to Norman.




April 22, 2011: Central Oklahoma

I messed around with initial storm development near Maysvill, OK, finding dime to perhaps quarter size hail as this activity began to organize. Thinking I might get into big hail, I took a long detour south to Elmore City, then caught back up with the storm cluster north of Pauls Valley. By 7-7:30 pm, somewhere near Paoli, it appeared that one updraft base/possible wall cloud moved off to the east, while another flanking cell rapidly intensified as a DRC-like rain core developed. The storm soon began sucking in scud, followed by a hook-like rain curtain wrapping cyclonically around the updraft base. Unfortunately, I decided not to mess with the trees and seemingly poor road options east of my location, and didn't see the tornadoes observed by other chasers at around 8 pm. On the way home, I emerged out of a heavy rain core and got a picture of the setting sun and a hail/rain shaft.


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