Chase Log: September 15th, 2006
Click on any of the SPC products below (Convective Outlooks, Watches, or MCDs) to see the SPC's "Severe Thunderstorm Events" page pertaining to this event.
Total Distance: 520 miles
Target Area: Arnett to Canadian to Meade
Chase Area: Gate, OK, to Ashland, KS, to Coldwater
Maximum SPC Risk category: Slight
Watches:
Mesoscale Discussions (MCDs):
Wow, apparently Ma' Nature switched May with September. A very nice, deep trough in the western US was the instigator for the first chase day in September 2006. The next day was supposed to be "THE day", so this day was more of the "day-before-the-day" type of event. Moisture wasn't terribly impressive, but we were hoping it'd be enough to result in sufficient CAPE in the very strongly-sheared environment. With intense deep-layer and low-level shear in place, we were just hoping the dewpoints and CAPE would be sufficient. A leading shortwave trough wasn't enough to initiate convection through the mid-afternoon, but we noted a rapidly-approaching secondary shortwave-trough rotating through CO and NM -- I just hoped it would make it into the area before the sun set. It was close...
My chase partner and I ended up on the supercell in Beaver, Meade, and Clark counties. We sat around Arnett, OK, for much of the afternoon, figuring that was a good spot to allow us to keep the southwest option open in case any storms developed in the eastern TX panhandle. Well, as it was, the only real convection that was able to persist was over the extreme northeastern TX panhandle. So, near 6pm (I think), we opted to close the southwest option and head for the storm then entering Beaver Co. For the first 20-30 minutes, the updraft(s) looked decent, but not entirely spectacular, with intermittent bursts of stronger convection / "pulses" very evident. By the time we go to Laverne, however, the storm had gained a backsheared anvil, and the structure improved nicely. We parked a few miles north of Englewood, KS, as the storm approached from the north. We started to run out of daylight, and we noticed a left-mover from the Beaver Co. storm to the south moving at "our" storm rapidly. Fortunately, for night chasing purposes, the supercell had an extreme amount of IC-CC-CG lightning activity. This supercell probably had the most intense lightning I've seen in a storm since 4-24-05 in SW MO.
At any rate, the left-split was rapidly approaching... I've seen good storm interactions (e.g. 5-4-03: the 90mph-moving left-split from a storm near McAlester hit the supercell along the OK/MO border, and that supercell reorganized within 30 minutes and produced the F4 Pierce City tornado), and I've seen bad storm interactions. This one was a bad interaction. Immediately before the left-split hit this storm, we watched a nice wall-cloud develop, and the shape just "screamed" tornado. Inflow increased rapidly, and both of us thought we were watching or near to watching tornadogenesis. Then it rained. Heavily. We had to relocate, so we lost the RFB for 5-6 minutes, but it looked like the wallcloud had dissipated anyway. We followed this storm for the next hour, watching intermittent wall-cloud-like features. Unfortunately, we had zero, zip, nada cellphone coverage, which meant no data and no voice-nowcast support. We called off the chase north of Protection, KS. Near the OK/KS border south of Protection, we stopped for ~20 minutes to watch an amazing site -- a very electrically-active storm cluster to our north in front of an extremely star-lit sky. There was little in the way of low clouds, so we had full view of a lightning-filled updraft, with thousands of stars in the background. It's easy to forget how many stars there are when you live in a city-light-filled area. Absolutely amazing views. I'll try to process pictures and upload them in the next couple of days.
As noted, we were on the storm during the time the tornado was reported 11mi southwest of Ashland, but we cannot confirm that tornado. In fact, I'm not even sure the low-level mesocyclone from that storm was 11mi SW of Ashland; The low-level meso that we were watching (and confirmed with radar), I think, was almost due W of Ashland when it was within 11mi. of that town. I know the next tornado warning for that storm mentioned that it was 7-11mi NW of Ashland, which fit our observations. Perhaps it was more like 15-20 sw of Ashland? Regardless, we didn't see it, so I'll remain slightly skeptical until I see pictures/video or damage reports (for which there should be some if it was on the ground for 2 minutes).
09-15-2006 Chase Pictures
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