Chase Log: May 22nd, 2004


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.


MAP

Total Distance: 1050 miles
Target Area: Manhatten, KS, to Hastings, NE
Chase Area: Belvidere to Auburn, NE
Maximum SPC Risk category: High
Watches: PDS Tornado Watch 251, Tornado Watches 249, 253, 254, 256
Mesoscale Discussions (MCDs): 821, 823, 825, 828, 829, 831, 832, 833, 834, 836, and 838

A nice outflow boundary was situated in a west-southwest to east-northeast boundary just south of the NE/KS border in the morning hours. A deep low was forecast to develop in northwestern KS as a strong trough worked out of the southwestern US and into the central plains. The situation looked like a pretty typical plains tornado outbreak, with very nice shear in the warm sector in KS and OK east of the dryline, which was located in western KS southward from the low. However, despite strong southerly flow for more than a week in the warm sector, only moderate moisture was in place (Tds generally in the 60s), which only yielded moderate instability and resulted in a pretty strong cap. While there was a small area between the edge of the instability (i.e. the dryline) and the western edge of the strong cap), we felt there was a pretty good chance of the cap holding along the dryline. So, we targeted the outflow boundary.

We left mid-late morning and headed towards Salina. However, after some nowcast updates, we opted to shift that target eastward a little due to dryline bulging near Salina. So, we headed for Topeka instead. By the time we were in Wichita, we got word that the new Day 1 outlook mentioned the very good possibility of an upgrade to High Risk for portions of southern NE near the outflow boundary. We figured that it didn't make sense to drive 4 hours to be in a very similar environment as just west of Norman, since this we were in an all-or-nothing situation. So, we drove north out of Topeka, targetting the KS/NE border. While we knew NE had the best chance of strong tornadoes, we also knew that the farther we drove north, the farther we would eventually have to drive south to get back home.

By the time we approached the KS/NE border, things were starting to look like a bust. The nice cumulus field that had been in place earlier was dissipating, as if the area was under strong subsidence. The lack of surface convergence was obvious and was supported by a look at the moisture convergence graphic on SPC Mesoanalysis page. Radar showed strong tornadic supercells in western NE, but those were 3 hours away still. Ugh. Could we have driving 5-6 hours to not see any daytime convection?!

Ah Ha! To our west we spotted strong TCU building as we drove westward on Hwy 136 in far southern NE. Soon, a very nice anvil was present (the best anvil I've seen to date) and the storm looked to be organizing rapidly. By the time we got to near Hebron, we pulled over to watch the storm. We knew the storms farther west were tornadic, but I couldn't imagine a reason why this storm wouldn't be tornadic also. Lo and behold, after watching the high-based storm for about 10 minutes, very rapid tornadogenesis occurred; it took about 2 minutes for a very low, rapidly rotating wall cloud to descend from the rain-free base. Seen thereafter, a lot of dust could be seen under the low-hanging wall cloud. There looked to be a few brief tornadoes during this point too, although they looked like brief spinups under the wall cloud. Whatever the case, we stayed with this storm, zig-zagging our way across the backroads of southern Nebraska north of Hwy 136. There was an unbelievable amount of dust being kicked up both by the rapidly-rotating wall cloud and the very strong RFD.

Near Alexandria, the wall cloud rapidly intensified again as condensation neared the ground. Soon enough, a very classic tornado developed north of us. After a few minutes, enough dust/dirt has been kicked up that the condensation funnel was completely enveloped in the dust/dirt. At this point, contrast and visibility became very poor as more and more dust/dirt obscured the tornado. Looking back through video, we can see the tornado nicely in the center of the wall cloud, although it was barely visible at the time. Several satellite tornadoes occassionally developed and rotated around the large, dusty tornado.

We continued to navigate the backroads as best as possible (courtesy of GPS), but the meso became completely (from our perspective at least) rain-wrapped, obscuring any possible tornado. As darkness fell, we stuck with the tornadic supercell Hwy 77 between Beatrice and Linclon. Near Firth, we drove through some significant tree damage, as power lines and trees nearly blocked the road in a few places. It looked to be all straight-line wind damage, as all downed objects were laying in a southwest-northeast fashion. Whatever the case, we could see occassional signs of a tornado and powerflashes to our north, but these were quick difficult to see. We did try to head north to get nearer to the tornadic circulation, but we also had to worry about another area of strong rotation to our west-southwest. We did make a move northward for a few miles, but we quickly encountered very strong outflow winds. Given the darkness and knowledge that there were two strong rotations near us, the strong (70-80mph) winds gave us quite a scare. Realizing that it was no longer safe for us to be there, we tried to get east enough to be able to drop south and avoid the tornadic storm to our west-southwest. For the next 10-15 miles, we encountered probably the strongest winds that I've ever driven through. While these times were very hairy (we just wanted to get out of there as fast as possible), we were finally able to get out of the path of the storms as we drove southward through Auburn. We then proceeded to head home, and we got back to Norman a little before 5am.

All in all, a pretty darn good day. I was very worried for about an hour or two while we were driving along the KS/NE border, as the cu-field diminished. However, the unbelievably rapid transformation from a high-based severe-warned storm to a tornadic supercell with very low-hanging and rapidly-rotating wallcloud that the storm near Belvidere experienced was the highlight of the trip. Granted, the long-track, large tornado in Thayer and Jefferson county was quite a sight to see. For that matter, so was the incredible amount of dust and dirt that was kicked up by this storm, both by the RFD winds and the inflow (which was VERY strong) into the mesocyclone.

05-22-2004 Chase Pictures

Click on any photo to see a larger version

This wall cloud developed in less than 60 seconds right before our eyes... Brief spinups were seen under this wall cloud. Whether they were gustnadoes or actual tornadoes is up in the air... This wall cloud developed in less than 60 seconds right before our eyes... Brief spinups were seen under this wall cloud. Whether they were gustnadoes or actual tornadoes is up in the air... The wallcloud persists and rotation increases as the storm moves to the northeast. The wall cloud continues to grow in size as an intense RFD pushes around to its south. Here's a nice dusty tornado, although it was very low contrast and difficult to see. The video grab above is another view of the (very) low contrast tornado from the south. The main wall cloud was west of this tornado. The tornad near Alexandria dissipated, and this new tornado developed along the periphery if an increasingly-impressive wall cloud / tornado cyclone. The cone tornado continues to slowly rotate about the center of the wallcloud / tornado cyclone. Contrast was very poor given the heavy precipitation core behind the tornado (from our perspective). The tornado is easier to see in the above picture with the help of some lightning The condensation funnel is no longer visible as dust completely envelops it. The transition to a monster wedge tornado has commenced. Courtesy of some lightning, we can see the actual size of the tornado, which is smaller than the dust cloud surrounding it. Another video still of the enlarging tornado. Contrast becomes VERY poor as a lot of dust kicks up under the wall cloud, in addition to the fact that the front flank downdraft is in the background. We began to lose sight of the tornado very shortly after this video was taken. In fact, we later think that the tornado had lifted since it was not visible (by us, at least). A nice little satellite tornado develops and rotates around the larger tornado, which is located behind and left of the small rope satellite. Another satellite tornado rotating around the main tornado, which is barely visible in the above still. The same satellite tornado rotating around the main tornado, which is barely visible in the above still. Notice how the west side of the wall cloud is just about touching the ground. Rotation on this feature was incredibly rapid. An obviously enhanced picture to show another cone tornado on the outskirts of the wall cloud. We lost contact with the tornado while driving through town, so I don't know for sure if this is another satellite tornado or if it is the main tornado, just taking a peek from the dust that had enveloped it previously. What town? I have no idea... Gabe was the navigator, and my GPS log didn't save correctly, so I don't remember where this video was taken. Near this time, a VERY large (2.5 miles wide) tornado was near the towns of Hallam and Firth, causing widespread damage. We were hearing reports of a tornado on the ground, but had no idea it was a 2.5 mile wide monster. The next few pictures are lightninng-aided stills of the RFD cut and the tornado (well, the left side of it at least). This was a case of "We were looking right at it, but didn't see it." Near this time, a VERY large (2.5 miles wide) tornado was near the towns of Hallam and Firth, causing widespread damage. We were hearing reports of a tornado on the ground, but had no idea it was a 2.5 mile wide monster. The next few pictures are lightninng-aided stills of the RFD cut and the tornado (well, the left side of it at least). This was a case of "We were looking right at it, but didn't see it." Near this time, a VERY large (2.5 miles wide) tornado was near the towns of Hallam and Firth, causing widespread damage. We were hearing reports of a tornado on the ground, but had no idea it was a 2.5 mile wide monster. The next few pictures are lightninng-aided stills of the RFD cut and the tornado (well, the left side of it at least). This was a case of "We were looking right at it, but didn't see it." The cloud feature just to the left of the middle of the video still is interesting. It persists in a near-the-ground fashion for several minutes. Because it is/was only visible with lightning, it is difficult to determine whether it was rotating or not.