***2005 Master Class Tour***

June 09, 2005 Northwestern Kansas Tornadofest

We intercepted two classic tornadic supercells this day: one near Hill City and the other in Trego County near Ellis. Below are the images and account from that incredible day!

Tour Leaders: David Gold and Bill Gargan

Tornadoes seen: 8

Number of supercells: 2

Meteorological Synopsis

Fig. 1: The 300 mb pressure chart valid 0z June 9. Note the deepening southwestern U.S. trough and attendant SW flow aloft over the central Plains.	Fig. 2: The 12z June 9 DDC sounding - a classic loaded gun indicating that the western KS atmosphere is primed for deep moist severe convection!	Fig. 3: 20 Z June 9 surface chart indicating the moist surface southeasterlies over southwestern Kansas and marked backed wind at Hill City. Despite the latter station's easterly bias, I believe this observation to have been representative of the backed wind regime in the vicinity of the southern most outflow boundary present over this region.	Fig. 4: The 19Z June 9 visible satellite image, with intersecting outflow boundaries noted in light purple shading. Notice the incipient convective tower near Gove, KS at this time. We headed right for this convective tower with no hesitation.

We began the day in Russell, KS, having driven until 1:30 AM from far northeastern Kansas (and from western South Dakota the day before that!). My primary concern the night before was whether the nocturnal convective complex that had become a nightly occurrence would wipe out the moisture over the prospective target area (Kansas/Nebraska). We were pleasantly surprised to awaken to stiff southeasterly winds at Russell, noting that surface dewpoints at Garden City and Dodge City were steadily rising through the mid-60's during the late morning hours. In fact, the Oklahoma mesonet plot ominously indicated that the western end of the outflow boundary left by intense overnight storms in central Kansas was beginning to wash out and move northward into southwestern Kansas, allowing lower 70F dewpoints to surge northward east of Dodge City. This situation is clearly noted on the 20Z surface chart (Fig. 3 above). We were further impressed by the large-scale pattern that was now in place over the U.S., featuring strengthening southwesterly flow aloft (see Fig. 1 above - I know, sorry they're out of order). The Dodge City sounding was another sight for sore eyes: the last time I recalled seeing a DDC sounding that looked like that, there were large tornadoes later that day downstream in northwestern Kansas. The strategy was simply to locate the "triple point" - the intersection of the dry line (note Garden City's post-dryline observation in Fig. 3) and the southern most outflow boundary (see the purple lines drawn on Fig. 4). This turned out to be fairly simple and we headed north and west into southwestern Graham County where we intercepted a rapidly intensifying severe thunderstorm. The summary of our chase is presented below.

Chase Summary with video captures

Impressive blocky wall cloud takes shape about 12 miles southwest of Hill City, Kansas.	A weakly formed truncated cone funnel cloud is seen with a pronounced RFD dirt plume to its rear. This feature did attain well-defined contact with the ground for a few minutes - tornado #1.	Ominous low-level mesocyclone really gets cranking south-southwest of Penokee still looking southwest from Hwy 24).	The beginning of the Hill City tornado (our tornado #2), looking about 6 miles to our southwest.
Tornado quickly morphs into a stovepipe.	The next few images show the various stages of this apparently strong and classic tornado as it moves east-northeast at about 25 mph.		Wish I had tripoded the camcorder at this point.
Why, oh why didn't I shoot stills??	Classic cone tornado with large debris fan!	Now we're moving into the western side of Hill City, the large dust-filled tornado looming too close for comfort to the south side of town!	We actually race south of town, intending to check out the quality of dirt road network there, hoping to remain closer to the tornado's path for the duration of its lifecycle.
Umm, nope! The roads down there were pure mud and would have made for a horrendous ride in the path of this beast. We blast back to town and then east, from which vantage point this image was taken (again looking southwest).	The next two images are panned out shots, revealing the full low-level mesocyclone structure with tornado beneath. Wow!	Again.	Tornado "wedges out" as the circulation fills with rain and dirt. Our vantage point is not good for lighting at this point.
Now we are just east-southeast of Palco on Hwy 18, the Hill City tornado having dissipated about 15 minutes earlier. Notice the precipitation-filled rear flank with low-contrast wall cloud in front - the hallmark of an HP (high-precipitation) supercell.	The storm re-attains a more classical supercell structure, the rear flank becoming less precipitation-filled. This permits us to see renewed tornadogenesis, up close and personal. Tornado #3.	The rear-flank mesocyclone produces a rather prolonged multiple-vortex tornadic phase, viewed at various stages here. I'm calling all of this tornado #4.	Some chasers were probably counting each and every phase as a separate tornado but I'm not. It's all one tornadic circulation that lasts intermittently about 15 minutes or so 2 miles NW of Palco, Kansas.
Another condensation funnel stabs to ground with tornado #4.	The storm develops yet another strong low-level mesocyclone on its southern flank. The strong RFD apparently contains enough dry air to make the associated tornado visible, and what a sight it was! Tornado #5 develops north of Zurich, Kansas.	Check out Roger Hill's van (with part of the Tour 5 group onboard) racing northward to get a closer vantage point!	This ghostly white cone tornado looked a lot more dramatic and spectacular than these crummy video stills can possibly convey.
This tornado apparently only received an F1 rating.	The group poses in front of the Zurich tornado.	This wide-aspect shot reveals that a separate tornado is in progress a couple of miles east-northeast of the white elephant's trunk tornado of the past few frames! Tornado #6.	A closeup of tornado #6.
Tornado #5 ropes out.	Tornado #7 on a separate storm moving towards I-70 west of Ellis, KS.	The storm structure associated with the Ellis tornadic supercell.	We witnessed one other brief weak tornado with the second supercell (not shown here), making a total of 8 tornadoes this day!

We intercepted the storm that would go on to produce the multiple tornadoes shown above over extreme southeastern Sheridan County. We went north out of Wakeeney on Hwy 283 and then west to a point northwest of St. Peter. We watched our storm's rain free base widen but then quickly get filled with rain as a new convective tower exploded on the storm's southeastern flank. This happened again, and we moved east and north in an attempt to stay out of heavy rain on the unsavory dirt road network in this region. Realizing that the storm was going to have some problems with new updrafts raining into the inflow region, we repositioned north to Hwy 24 at Morland. We also did this in anticipation that storm motion would be northeast and then eventually east-northeast. We moved slowly east on Hwy 24, inching our way towards Hill City, KS over the next 30 minutes, watching as the storm continually reorganized on its southeastern flank, each new updraft developing a mesocyclone more impressive than the last. Eventually, just southwest of Hill City, the storm changed character radically as one of the most amazing low-level mesocyclones (structurally speaking) I’ve ever seen formed - replete with double tail cloud and full of horrific motion – about 10 miles SW of HLC. A large dust swirl formed beneath the growing wall cloud/meso – tornado #1. This mesocyclone continued to grow in size and the rotation increased to tremendous proportions, focused intensely in the center and finally culminated in the very rapid formation of a stout classic stovepipe tornado, very well-contrasted about 7 miles S of Penokee, KS. This strong tornado developed condensation to ground at around 4:23 pm CDT and remained on the ground for about 25 minutes or so, remaining a large tapered cone tornado (inky black and well-contrasted from our vantage point to its NE).  It passed about 3 miles south of HLC, partially wrapping in precip from the RR core and shrouded in dirt. We blasted south out of HLC to try to use the dirt road network south of town but didn’t like the muddy look to the road surface so we blasted back north and barely beat the FF core and its baseball sized hail (I saw some enormous stones on the road in town as we flew east). The tornado was now a stout barrel and contrast gradually worsened. It became a fat barrel/wedge tornado SE of town with crazy motion visible up the side walls. The tornado completely rain-wrapped shortly thereafter. We broke off onto Hwy 18 and watched as the storm underwent an evolution to HP and then (surprisingly) back to more classic as a new mesocyclone got cranking NW of Palco. We were within one mile of a beautiful multiple-vortex tornado W-NW of town and then we went SE down 18 as a horrendous RFD surged east (Bill really had to fight to keep the van steady in the stiff westerly winds). Then, near Zurich a truly beautiful ghostly white large stovepipe tornado formed and moved east-northeastward across farmland north of town. A second large truncated-cone tornado with large debris cloud formed and churned simultaneous with the white stovepipe/elephants trunk. We broke off the chase south of Stockton (fully aware that we’d probably miss more tornadoes to the north-northwest) and targeted the Wakeeney storm near Ellis where we witnessed a so-so contrasted (from our view point on I-70) tapered cone tornado. We saw another couple of brief slender truncated cone tornadoes north-northeast of Ellis and then we broke off the chase. This was a memorable day to be sure!