We started the day in Kearney, Nebraska and headed west with a fairly broad target area. A large trough was located over the Rockies with 30 to 50 knot 500mb winds blowing across the Plains. Plenty of low level moisture was in place east of a dryline that by afternoon would run from Southwest South Dakota to West Texas.
The storm that produced the Big Springs tornado made narrowing down the target area easy. It formed straight west of us with I-80 taking us right to it. Timing couldn’t have been better.
We found ourselves directly under the meso-cyclone about midway between Julesburg and Chappell when the tornado developed just to our southwest. It moved just south and east of us steadily growing in size and intensity. It was on the ground for 40 minutes and 10 miles before weakening about 8 miles northwest of Big Springs. While staying in rural areas, the tornado did injure two people.
Video capture of the tornado illuminated by lightning.
Intense supercell storms formed across Southern Kansas during the afternoon and evening of May 12th. There were several tornadoes produced across Harper County with different storms.
We approached the area from the north, having chased in Nebraska the day before. The target area was fairly small, but quickly became cluttered with numerous storms. We first observed storms near Pratt and Sawyer, while hearing reports of many tornadoes from a storm to our south. We had made the decision to try and catch up with the southern storm, which ended up putting us in good position for a new storm that formed southwest of Attica.
It was after dark by the time this storm began producing tornadoes, but we had good visibility and a good east/west road to operate on which made for a nice intercept. The tornado which formed about 6 miles east southeast of Attica was on the ground for 13 minutes and four miles. It stayed to the east and southeast of us and was only seen with lightning flashes. While feeling safe at our location, it still made for an eerie experience only being able to see the tornado with lightning.
VIDEO PART 1: http://www.youtube.com/watch?v=A4oxyGPmmQg
VIDEO PART 2: http://www.youtube.com/watch?v=gFylAp5osv4
Looking back, I’m not sure I would pull the trigger on chasing (from Oklahoma) if this same setup were in place today. There was an upper low over the Western U.S. with decent 30 to 40 knot flow spreading over Colorado. Low level moisture was returning on upslope flow and it definitely looked like a day where you could get some supercell storms. If I was in the area on a chase trip I would be excited about the days potential, but I don’t think I would make the drive from Central Oklahoma for it.
I did, and was rewarded with an amazing supercell that produced seven tornadoes. The fun of the day was tempered somewhat by a horrible sinus headache that attacked me during the afternoon and didn’t begin to release its grip until close to the last tornado of the day.
The supercell that was responsible for the tornadoes northwest of Limon was an interesting one. It spent most of its life slightly stretched out from west to east and usually had more than one – sometimes three – meso-cyclones. The tornadoes that were produced moved generally due north, resulting in paths that were parallel to each other, but with a progressive farther north latitude. The tornadoes would tend to move to the northwest near the end of their lives.
In retrospect, it was a privilege to have been able to view this supercell. It would have been nicer with about an hour more of light, but still very impressive none the less. I saw very few storm chasers, but it did put on quite a show for the locals. As I was driving north out of Limon, there were yards full of people in lawn chairs that were viewing the spectacle.
It should tell you what kind of day it was when I went to the SPC storm events browser and found they didn’t have a page for April 6, 2004.
An upper low over West Texas moved northeast during the afternoon with strong flow and cold air overspreading a region of 50 dewpoints with CAPE around 1000 j/kg. Several low topped supercells formed and I observed at least three different storms near the Red River, all with typical supercell features. Wall clouds with slow to moderate rotation were common. The storm which ended up producing the weak Hollister tornado formed near Oklaunion, Texas and moved northeast around 15 mph. The tornado itself didn’t appear to be more than 20 to 40 yards wide. I think it made the SPC log as having a width of 10 yards. It was on the ground for two minutes.