June 24th was a surprise day for me. Fairly poor low level shear, little forcing, no decent boundaries, and only meager moisture had me concerned about the quality of a storm today. I wasn’t even sure a storm would form. However along a confluence line, towering cu went up late afternoon, and a gorgeous supercell formed. This storm refused to quit and even after we left it, it was still severe and even briefly tornado warned. While we were chasing it up until dark it had been tornado warned twice with one very convincing funnel reaching 3/4 of the way to the ground. However, I can not confirm a touchdown. Nonetheless, it was a very pretty classic supercell most of its life cycle.
July 19th, 2008 North Dakota Incredible Supercell!
July 19th was a day I thought we would be in Canada. A strong trough, with good moisture and instability tracked along the US and Canada border. A boundary had formed from northwest North Dakota into western Iowa and would be the focal point for severe storms. We intercepted a supercell near Williston, North Dakota and tracked it well south of Bismark, North Dakota, over a 10 hour chase! It was either severe or tornado warned the entire time. What a beautiful storm. It arguably was the prettiest supercell of the year. It produced dozens of severe hail reports including hail baseball sized.
June 23rd and 24th, 2008 Northern Plains Supercells
June 23rd and 24th kept us in the northern plains, from Nebraska to North Dakota. Ample moisture, decent shear and good instability would provide for severe storms on both days. Several tornado warned and severe warned storms would form, but would not produce tornadoes. Instead very large hail to baseball size and strong outflow winds would be the primary severe weather modes. Structure of HP supercells and a magnificent shelf cloud from a bowed out line in North Dakota on the 24th would give me great photo opportunities.
June 26th, 2005 Dakotas Tornadic Supercells
Being the first day of the tour, we drove QUICKLY to South Dakota where we caught a decent supercell. Conditions looked good with high instability, decent shear and an outlfow boundary from previous night convection to focus intense convection on. It produced a couple of weak tornadoes before lining out. We then blew it off and drove towards the Bismarck, ND area where we caught a nice sculpted supercell that produced a couple of weak circulations.
June 6th, 2004 Max, North Dakota Tornadic Supercell
This was a tough one for me. We left Denver early this AM with a target of Dickenson, ND. After almost 800 miles, we arrived to see 3 high based storms get their act together. Strong moisture return ahead of a short wave trough would provide lift to get these storms going. In spite of only upper 50s dewpoints, these 3 storms turned into supercells, with the southern storm, near Max, ND our target. We arrived as the storm was a beautiful saucer base with clear slot. A couple of funnels formed and extended close to the ground. Close enough I would consider this tornadic.
June 9th, 2001 Bismarck, ND Supercell & Tornado?
June 9, 2001 took us to North Dakota. Never again will I underestimate the importance of a boundary in tornado genesis. A weak bubble high formed over South Dakota after a morning MCS moved through, scouring out all moisture. However, north of the warm front in western North Dakota moisture was pooling with dewpoints in the 60s. So north we headed. There was 50 kts at 500 mb, great veering profile, high CAPE, and an approaching short wave. On the way northward through South Dakota, dewpoints bounced from the upper 40s through the 60s, but by the time we hit I-94 they increased to 66F. A couple of severe storms were ongoing, with one storm potentially tornadic. Other storms rapidly formed along the boundary, which was also collocated with I-94. Within 30 minutes upon arrival, a supercell exploded just to out east, so we raced after it, and what a show it gave us. Rapid cascading from the RFD was visible, huge hail soon followed, and finally as we got in front of it a possible tornado crossed in front of us causing significant damage.
June 12th, 2000 Grand Forks, ND Tornadic Supercell
After a fun tornadic supercell near Bismarck, ND the day before, June 12th turned out to be a day not soon forgotten. We stayed around the Bismarck area until shortly after noon watching and waiting. We noticed on a satellite pic that congestus was forming on a nice convergence boundary from west of Grand Forks to near Jamestown. So off we went, to get into position for our first storm of the day, and what a storm it was. We arrived near the Larimore, North Dakota area around 6:30 PM as a possible tornado touched down along a wall cloud/updraft just to our northwest. Power flashes confirmed something under this wall cloud.
The first storm weakened so we headed east on Grand Forks county road 6 to road 3 and watched a nice elephant’s trunk tornado form about 2 miles east of us. This only lasted for about 5 minutes then dissipated at 7:48 PM. We decided to get in front of this supercell and shoot some structure photos, and WOW! What a mothership storm!!!!