The first day of my North Land Lecture Tour resulted in a “south land” weak tornado! What a surprise! We headed south from Denver and crossed the Raton Mesa, only to see what looked like supercell structure near Mt Capulin volcano. East we blasted and caught up to this cell as it produced a distant weak tornado!! What a surprise!! Later on, a weak LP type supercell formed near Springer and had decent structure for awhile.
June 23rd was a day that had promise for high based storms in western Nebraska. It lived up to its potential and more! We caught the first supercell of the day that formed northwest of Scottsbluff and was a nice LP storm. The second LP storm formed northeast of Torrington and had very nice structure. And finally the storm of the day formed west of the Black Hills in northeast Wyoming and tracked southeast into northwest Nebraska. This storm had beautiful HP supercell structure and produced a couple of short lived tornadoes, one of which is shown below.
A few boundaries, good shear and adequate moisture would allow supercells to develop in northeast Colorado and western Nebraska. We first targeted a supercell and complex northeast of Alliance, but when we saw it was a left split we blew it off (mistake as it produced tornadoes!). The storms in Colorado were quite outflow dominant, except for the third supercell which was a respectable classic supercell near Yuma. The Colorado storms never produced tornadoes, but did have nice structure, lots of lightning and hail to baseball size.
June 14 ended up being a disasterous day for us. The day started out with lots of promise as a strong wave was moving across the intermountain west with tons of shear. Moisture was fair and we expected some nice rotating supercells. We drove west of Broadus, MT in search of a new and intense supercell that formed west of Sheridan, WY and was tracking north. As we approached it near Crow Agency it bowed out and became a deviant moving storm. We tried to get back east to get ahead of it, but traffic soon stopped us as we took the brunt of this monster hailstorm. Wind of 95 MPH drove hail to golfball size into the vans and knocked out windows, injuring Caryn with flying glass and hailstones. After a quick trip to the emergency room, she was ok, but with tons of bruises.
I wasn’t expecting much this day, but couldn’t resist a play off the Black Hills of South Dakota. By mid afternoon a VERY high based supercell formed near Hot Springs. As it moved off the hills, it weakened and almost died. Then, not far from the western edge of the Pine Ridge Reservation, it intensified and became a wonderful high based hailer. The structure was as textbook of an LP as one could get. The most beautiful part was right at sunset as the sun lit the updraft and anvil, complete with reflected convection in the anvil.
June 11 was the first day of tour 6. We debated on whether to stay in Colorado or head north. Surface flow and moisture was a bit better north into southwest Nebraska. And after a call from Dave Gold, north we headed. We arrived on the scene near the Scottsbluff National Monument to see a beautifully striated rotating supercell sucking dirt off the top of the monument. This storm did all it could to produce a tornado, even with a strongly rotating lowering on the northeast side of the storm. But it never could quite focus long enough to produce. However the structure was incredible!!!
June 10 was a down day for Silver Lining Tours. However it was just too enticing to sit around as a severe storm developed along a boundary northeast of our house. We caught up with the storm near Last Chance, CO and stayed with it all the way to Burlington. This storm had fantastic structure with the beautiful “upside down wedding cake” look to it. However the tornado threat was nill as it was very high based. Nonetheless, it was a spectacular storm that produced hail to tennis ball size.
June 9 would be a day where several supercells formed along an outflow boundary/cold front over central and northern Nebraska. We intercepted 3 nice storms there. The first storm was a classic with large hail and high wind. The second was another classic that was tornado warned and had beautiful structure, and the thirds was a beautiful LP. Shear was great, instability good, but moisture was a bit lacking.
Montana was the place to be on June 8. A strong short wave pushing across the state would spawn supercell thunderstorms off the northern Big Horn mountains. We intercepted 3 supercells. The first was a dying beast that dumped hail baseball sized over the area. The second developed a well defined wall cloud and I though for a few moments there could be tornadogenesis any moment. The third supercell was the storm of the day. It developed just east of the first two on the outflow boundary. It became a striated monster, with a well developed wall cloud (above). A clear slot formed and strong RFD winds cut into the back of the storm. We came very close to a tornado as the wall cloud, now rapidly rotating passed just north of Lame Deer. Finally it became an HP storm and eventually gusted out. Thanks to Caryn for her superb driving skills keeping us ahead of this beast on dirt and gravel roads!
June 6 was a day that had decent supercell potential, but we underestimated the tornado potential farther north. Several tornadoes touched down in Wisconsin, which was too far for us to get to. We played the outflow boundary/front intersection over eastern Iowa. By mid afternoon, a supercell developed near Iowa City that became tornado warned for 2 hours, followed by 2 more supercells farther south in Washington county and finally Ottumwa that were beautifully structured. The corkscrew supercell above was near Ottumwa and was tornado warned, and rightfully so! In the end, the low level flow was just too weak to produce an significant tornadic activity.