Green Sky Chaser

16 May 2010 Chase Log

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Target Area: Oklahoma City, Oklahoma (Click on city names for Yahoo! maps links)

Chase Area: Oklahoma City, Oklahoma

Observations: two supercells, hail, lightning, and a rainbow

Distance: 80 miles

Time: 3 hours

Chase Team: Jeff Makowski and myself

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

Chase Setup: A weak, broad trough was located over the Central Plains and a frontal boundary and/or wind shift line ran through western into northern Oklahoma. Dewpoints in central Oklahoma were in the low to mid-60s and CAPE was over 2000 J kg-1. Wind shear was not very strong, with northwesterly surface winds and westerly winds aloft. However, mid-level lapse rates suggested a large hail threat and some multi-cells with severe hail were expected in Oklahoma and north Texas.

Blog Entries:

Impromptu Chase #7 (before)

Chase #7 Evaluation (after)

Oklahoma City Hailstorm (after)


Chase Log: Just before 3 pm, I noticed a nice-looking HP supercell was tornado-warned just northwest of Oklahoma City, moving to the southeast. I texted Jeff, to see if he wanted to go chase it, when I got a call from KSBI. They asked if I was available to chase for them, so Jeff and I left for Oklahoma City in less than 30 minutes.

We drove up I-35, took I-240 west, I-44 east, and then I-235 south, when we realized the storm was coming at us a bit too fast. We got off I-235 at the State Capitol, and briefly stopped at a gas station at the intersection of NE 23rd St and Santa Fe.

After watching a possibly slowly rotating cloud and a very large hail core and green sky come towards us, I decided to drive east a bit to intercept the largest part of the hail core. However, no sooner did we leave the gas station than we realized we might not make it farther east before the core hit us. I briefly drove around the capitol building, trying to find my way back to our gas station.

Eventually I made it back, and squeezed my way in between several cars taking shelter under the roof. Rain started to pour down, as well as some small hail. We saw some lightning around this time, but it was mostly obscured by the rain.

Once the rain and hail started to taper off, and enough cars got out of the way for me to leave, I drove off into the gas station parking lot to get some photos and video of the hail. The largest hail stones I saw were about quarter-size (1-inch diameter), though most of them were about marble- to dime-size or even penny-size. We heard on the radio that baseball-size hail stones were falling to our east, but we were not able to get there in time to see them.

After briefly going on air to talk about the hail footage we were streaming, we drove south on I-35 to Tecumseh Rd, at which time we headed east again to follow the storm. By the time we got to Alameda and 60th Ave SE, I got a call to head back west as there was another storm near El Reno.

Just west of 60th Ave NW, on Tecumseh Rd again, we stopped to photo and get video of a beautiful, towering LP supercell. The supercell was high-based, and although we were about 4 miles east of Newcastle and the storm was roughly 20 to 30 miles away, we had a great vantage point to just sit and watch the storm. The storm briefly took on a stacked plate appearance, and I did study a couple of pieces of scud underneath the updraft base to confirm that it was rotating.

Eventually the storm base began to erode, around the time we saw one of the University of Massachusetts radar trucks pull up behind us to scan the storm.

From then it was only a short drive back to Norman, where we saw a nice rainbow in the east. It was a great little storm chase, though it was unfortunate that the hail storm was so costly (see this site for NWS maps, photos, and information on the hail storm).


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