July 23rd, 2010
The luck of the slight risk continues. Expectations were NOT high for this day, especially so since I hardly knew anything about forecasting parameters. It was my first year of chasing so I didn't know a whole lot about forecasting, but I knew a slight risk in South Dakota meant you chase. Regardless, wasn't expecting anything big out of this day. Really just wanted to get out one last time before summer was over, and in late July, you start running out of options for real storms to chase real quick. Met up with Chris and Guadalupe and headed north on I-29. Kind of odd having a third person in the car, but it almost always helps pass the time better. Something about adding a third person that increases the level of shenanigans.
Ate lunch at Dairy Queen in Mitchell, SD and met up with Mike Hollingshead in the parking lot to look over data. From what I recall, there was talk of crappy surface winds and general pessimism based on visible satellite lol. Think we still had some crappy stratus left over, not a good thing when you need your daytime heating to kick in. Continued to head west on I-90 and finally stopped in a gas station parking lot to watch turkey towers to our west. Just little convective updrafts that would start to build, but then get sheared over and wisp out.
After over an hour of waiting, we finally decided to head west just to get closer to stuff. Didn't have a real great view of the towers on the southern end, but once we left the parking lot, it became apparent that the show was about to start fast. What looked like a regular tower as we left the parking lot soon exploded and began to anvil as we got closer. Really nice anvil on the thing, no wispy edge crap here.
Sitting west of Vivian, SD now, which was kind of funny since earlier Chris mentioned how he should take a photo of the Vivian sign since he had a relative by that name. Ended up sitting on an exit just off interstate waiting for our storm to get closer. Still hazy back there, but you could tell something was back in that darkness. Kind of tough to make out in this image, but if you look closely you can see a small landspout/spin-up along the horizon just above the sign left of the "do not enter" sign.
Had some crunchy elevated cumulus in front of our storm still. Wish it all would have gone away to leave us with a clean-air supercell, but at least it made for something to shoot while we waited.
Now we finally had our structure coming into view. Just sort of a disorganized stack of plates, but a stack of plates nonetheless! Chris checking over data with Mike. Believe they were looking at the maxed-out VIL (vertically integrated liquid, i.e. hail) scan of our storm. First sign of what was to come lol.
We finally get under our storm, and are immediately greeted by what looked to be an outflow-dominant mess. Couple random shear funnels in this image, the zig-zag one on the far left and a more straight tube roping out closer to the right.
The storm starts to re-organize itself as we follow it eastward. Some pretty crazy textured plates at this point, with elevated textures overhead but a very very low ground-scrubbing section back in the darker area. Looked like something tornadic could be happening back in there, but I don't think anything was reported at that time. The real danger wouldn't end up being tornadoes though.
Sit there for a couple minutes and the thing caught up pretty dang fast. Already had the southern end over us again, which began blasting us with some rain-cooled (or hail-cooled?) air. Right about at this point, the town of Vivian, SD is getting bombed by bowling ball-sized chunks of ice.
For more information on the extreme hail event, check out the link below:
(Not my image. And keep in mind, that's after a considerable amount of melting. MASSIVE!)
Oh, and the updraft speed required to support a hail stone of that size? About 180mph. So basically an F-1 racer, going straight up.
A few little blips of storms kept firing out in front of it, but the beast kept ingesting them, essentially turning them into its own convective inflow. Didn't stop to shoot at the time, but I captured an interesting cyclonic/anticyclonic interaction in the base of that convective inflow. Pretty crazily well-defined little spinning zones in there. Like a cinnamon roll in the clouds lol.
Got ahead of it enough to pull off and shoot it for a couple minutes again. Really starting to take on some nice organized structure now as it crossed I-90. There's Mike in the foreground speeding off as I take one last shot. He was smart and decided to follow the storm on interstate. We made the mistake of trying to follow it a bit further south on dirt since it was tracking ESE.
Here's where we pull off interstate and get on dirt lol. Could see cars starting to huddle under the overpass waiting for the hail bombs of doom to start raining down. Really odd structure at this point.Some striations to the left with the organizing meso, but what looked like whale's mouth textures overhead in what would be the vault.
Finally got a pano of this scene to stitch.
NOW we're talking. Structure had been interesting visually but only so-so on camera so far, but things really started to ramp up now that we were on dirt. Can see the vault clearing out on the right, and some better inflow features forming on the left as it ingested another cell.
Vertical of this scene looked pretty nuts. Wish we could have shot here longer, but this was right about when the hail bombs started to fall. Think Chris heard a baseball whiz by and land in the field and we decided it was time to get out of there lol.