Updated on June 29 with full account including many photos:
On Tuesday 6/20, I wanted to take advantage of a day-off work to chase. As mentioned in the previous blog post, I liked the area in northeastern Colorado where post-frontal moist upslope flow was best…along the Cheyenne Ridge.
I left Dodge City around mid-morning, arriving in Oakley around 11am where I stopped at the library to refine my target. Keep in mind, I was chasing more “old school” this day… with no laptop computer… so I had to rely on my morning forecast and one or two updates until I got to my target. This gave me the opportunity to actually sit down and do a surface map analysis at 16z (see below).
At 16z (11am CDT), the surface winds in my target area were out of the north around 10 knots. Traditionally, this is what you do not want to see the late morning hours in your target area. The “rules” are a lot different on the high plains adjacent the Rockies, though. All the models clearly showed these winds veering around to the northeast then almost due east by 00z (7pm)… the prime time for photogenic storms. The low level moisture was very good for this region in the north surface winds, as you can see on the surface map… for those chasers/weather weenies/meteorologists who know how to read these
I then stopped for lunch and another quick update at the NWS in Goodland. Everything appeared to be on track, so I continued my trek to the Akron-Sterling area. A couple of developing storms were visible to my distant northwest when I arrived in Yuma, with the most prominent storm about 80 miles to my north-northwest along the Cheyenne Ridge near Sidney. This was my initial target storm, so I set a course for the Sterling area…and then points north from there should the storm hold together. By the time I arrived in Sterling, the storm was not looking nearly as organized. Jay Antle was nowcasting for me and he advised of a storm well to the north near Scottsbluff/Alliance, NE. At the same time, other towering Cu were developing to my west. I headed northeast on I-76 about 20 miles to the Crook exit. I hung around at this interchange, monitoring the developing towering Cu field back to my west. Another call from Jay advised that the radar echoes aloft were really increasing in the New Raymer area…about 50 miles west of me. This activity was moving in my general direction… and by the time an anvil canopy was established… I backtracked southwest about 10 miles to the Proctor exit, where I re-fueled and began my chase.
At Proctor, I headed west a few miles on the county road grid…then south, south of the interstate towards the Fleming area. I had this view of the developing storm to my west at around 4:30pm MDT. The storm was still fairly disorganized with at least three areas of updraft development from west-southwest through northwest. About 4:50pm, 5 miles south of Fleming, the updraft base was looking more impressive (1 2 3), yet still pretty elongated. While this was going on, another storm was developing almost on top of me, just to my immediate southeast. I was beginning to get rained on and I had to move. I was discouraged by this new, weak storm near the inflow region of this storm. I drove east on a county road southeast of Fleming to stay ahead of the main storm to my northwest…but driving through light rain from the new weaker storm to my immediate east. While I was driving east, a tornado warning was issued for my storm behind me to the northwest for a reported tornado northeast of Sterling. Whether there was really a brief tornado or not, it had to have been spawned from the updraft base I was watching/photographing south of Fleming. There could have been a weak, brief “landspout” type tornado, but I’m a little suspect of the report.
In the meantime, the storm to my immediate east was getting better developed, but it was finally moving far enough east/northeast of me. The main storm back to my northwest was still holding its own, but things were about to change very rapidly. My location was about 6 miles southwest of Haxtun where I stopped briefly along a north-south paved county road. Matt Crowther, who was also providing me nowcast help, called me on the phone to give me a radar update. In a span of less than 5 minutes, my main storm to the northwest was rapidly evolving into a bonafide supercell storm. The updraft base became much more focused and taking on rotation, with a wall cloud to boot (1 2). The wall cloud attained some rotation, but at the same time, it was becoming undercut by outflow. Remember that weak storm to my immediate east? Well it had now merged with the main storm (vertical) and was taking on impressive structure. The storm was now evolving into an HP supercell with a ton of precip. This is a look to the north at the portion of the storm that was originally that weaker storm out ahead of the main storm.
All this precipitation the storm was generating was detrimental to the supercell itself. It generated a huge surge of cold outflow surging south. Here’s a look to the west at the southern edge of the storm updraft, and another broad view of the entire storm updraft region. The supercell had pretty decent structure at this point (around 5:25pm), looking west-northwest from a location about 10 miles southwest of Haxtun. This would be the last of the good structure, though, as cold outflow would out-race the updraft enough to cut-off any good inflow into the storm. It looked really menacing to the north for awhile, but all this outflow became the death of the great supercell structure. It did make for some picturesque outflow-dominant structure (1 2 3) for awhile! (~5:33pm).
So now I had a decision to make. This storm was “going to pot” now with so much outflow ruining the show. I headed south on Hwy 59 to try to stay ahead of the outflow, with still some remaining updraft structure. I thought that it was still pretty early in the game, not even 6pm MDT yet, and there was always the possibility of the outflow surge becoming less dominant with new development farther south. In the meantime, the main original storm was still going, but the structure wasn’t nearly what it was to the north. I headed south to Clarkville, then east on Road 55 until I got to the sand hills where I had to head south a mile then east one more until I got to Road 51 which meandered through the sand hills. In this area of northeastern Colorado closer to Nebraska, you start entering more sand hill terrain. For future reference, Road 51 in northern Yuma County…between Wauneta and and Clarkville…is a wonderful little drive through the beautiful sand hills. The storm to the north-northwest was holding its own (6:30pm) despite being in that horrendous cool outflow generated airmass.
I was watching this storm overlooking the sand hills for a good half hour while meandering eastward towards Wauneta. The NWS-GLD office actually issued a tornado warning for this storm, which I found really interesting. At no point did this storm appear capable of producing a tornado with the messed up outflow environment it was in. As the sun was getting lower in the sky, thecolors were becoming more saturated and picturesque ( 1 2). The storm was looking more like a marginal supercell again to my north. I reached Hwy 385 at Wauneta and continued east a couple more miles with the storm to my northwest. It appeared as if the storm was on the downward swing and my attention was now becoming more focused to the new storm to my southwest near Yuma. I backtracked to Hwy 385 then continued south towards Wray to intercept the Yuma supercell. I stopped briefly to take one last look and photograph the Wauneta storm. Now it’s onward to the Yuma storm! (time ~7:35pm).
This storm must have formed at the edge of the surging outflow… and the ouflow must have come to a halt, because this storm was very well organized. It was a race against time, though, to get quality photography of this storm before the sun set. As I headed west from Wray on Hwy 34, there was a problem. The lighting was horrible with a lot of downstream precip being blown due east of the updraft area. Looking on the horizon, there were clear skies to the southwest and due south of this storm, so this was where I had to be… due south of the updraft, not east. With this in mind, I had to hop off Hwy 34 and drive south on unpaved county roads.
I had to find the photographer’s light… it had to be there! …and oh did I find the light. About 10 or 12 miles southwest of Wray…about 7 miles south of Hwy 34. I got south of the supercell updraft just in time for sunset. I quickly got the tripod out and had a field day. The colors were simply incredible. The warm hues of violet, orange, gold, blue… were stunning to say the least… and the supercell structure was very nice as well.
1 | 2 | 3 | 4
The view from west through north through east was just full of virbrant hues…illuminating the cloud structure of the supercell magnificently (vertical).
Immediately after sunset, the sky just lit up on fire. Vibrant pinks and violets dominated the sky…and cast an incredible hue on the landscape:
1 | 2 | 3 | 4
Once this great light faded… so did the storm chase. It was exactly what I was after…incredible light on a supercell thunderstorm. I drove south to Burlington to refuel and grab a bite to eat. After taking about an hour nap west of Goodland at about 12:30am CDT, a storm was developing nidely to the east. I stopped for about 20 minutes to photograph lightning near Edson along I-70. On approach to Dodge City around 4am, another storm was producing photogenic lightning just before arriving home, which was a nice little touch to the end of this chase. 1 | 2
http://www.underthemeso.com/gallery2/stormchase/chase06/2006jun20/
Mike Umscheid