Mike Umscheid
EF4
LP Supercell near Colony, WY
Vince and I began the day in Miles City with the primary chase target in mind being North-central North Dakota where low level moisture would be greatest and low level winds would be more backed. One problem was the cap, and we knew it would be very difficult to overcome given the lack of strong forcing. A secondary target closer to our location was to our southeast near Alzada, MT where low level moisture with dewpoints in the mid 60s would remain in place most of the day. The RUC model was showing this moisture mixing out by afternoon significantly reducing the CAPE... however surface observations just were not suggesting this. Just after we departed Miles City, we took a look at the new SPC Day One outlook update and they increased the tornado and hail probabilities in our secondary target area. Once again, I took another hard look at obs...and more and more, the 60s dewpoints from Sheridan to Gillette were just too much to ignore, plus I could see some low Cu on the visible satellite image just off the Big Horn Mountains near Sheridan, WY. We abruptly pulled off I-94 and abandoned our 6-hour pursuit to North Dakota. This was the big turning point of the chase... the quick decision to go after this secondary target that was much closer to us... with much less stress involved.
We sat in Baker, MT for awhile monitoring obs and satellite. More agitated Cu was developing near Sheridan and it became more and more probable that this is where we needed to be... or at least immediately downstream of this area... so we set our sights on Alzada. We drove south admiring the beautiful terrain and even stopped briefly for some landscape photos near Albion before continuing on with the chase. A quick gas stop at Alzada and we were on our way. Some nowcast support from Matt Crowther was helpful in determining our route. A storm was rapidly developing in front of our eyes to our west-southwest. We decided to go due west on a gravel road (Ridge Rd.) several miles. It didn't take long for us to start seeing structure. We pulled off at a relatively high spot and admired the beauty in front of us. A barrel updraft became better established with a long beaver tail to the north feeding into the updraft. Our surface winds had a northerly component. The real-time motion in the updraft was just incredible. You could see the rotation real-time with the corkscrewing action in convective elements of the updraft. The character of the storm was on the dry side of classic on the supercell spectrum...but eventually, as we traced our steps back west, the storm would become more low-precipitation (LP) in appearance and would take on some of the most impressive LP supercell structure I've ever seen! The storm was moving east-southeast and we had to get back east to Hwy 212 so we could continue to stay ahead of it. We stopped a couple times on the highway north of Colony admiring the sculpted beauty. The blue sky behind the storm and the small precipitation shaft made for perfect photography light/color contrast. No words can describe the sight! We ultimately made it towards Belle Fourche, and the storm took on a different character again... looking more classic in appearance with a larger base. We shot more photos at a pull-off between Colony and Belle Fourche and learned of the gigantic hail the storm was producing... softball and grapefruit size hail!! Fortunately, we didn't experience that as we stayed just far enough ahead of the updraft. The storm took a downhill trend as it moved northeast of Belle Fourche and we decided to head back west again after our final stop-off just northeast of town.
We went back northwest on Hwy 212 after we learned of new storms forming in the same exact location as our original supercell developed. (Thanks Dave Ewoldt!) Unfortunately, low cloudiness was increasing and obscuring our view as a strong cold front was pushing south. We decided to head back to Belle Fourche or Spearfish for the night...however on our way back, we learned that a supercell had rapidly formed again from that new activity... but we just couldn't see what was going on given the low clouds. Nevertheless, the storm was moving straight for us and we decided to mosy west on I-90 to see what up. We got as far west as Buelah a couple miles into Wyoming. We noticed impressive anvil zits with high-frequency in the few holes in the stratus... it's a shame the low clouds were as bad as they were. The lightning photography was really a bust from this storm. Eventually, we made it back to Belle Fourche again for the night after being chased to Sturgis by the supercell complex.
Again, what a day! Thanks again to Matt Crowther and Dave Ewoldt for nowcast support in our non-internet areas.
Photos below... a few more on my blog
Vince and I began the day in Miles City with the primary chase target in mind being North-central North Dakota where low level moisture would be greatest and low level winds would be more backed. One problem was the cap, and we knew it would be very difficult to overcome given the lack of strong forcing. A secondary target closer to our location was to our southeast near Alzada, MT where low level moisture with dewpoints in the mid 60s would remain in place most of the day. The RUC model was showing this moisture mixing out by afternoon significantly reducing the CAPE... however surface observations just were not suggesting this. Just after we departed Miles City, we took a look at the new SPC Day One outlook update and they increased the tornado and hail probabilities in our secondary target area. Once again, I took another hard look at obs...and more and more, the 60s dewpoints from Sheridan to Gillette were just too much to ignore, plus I could see some low Cu on the visible satellite image just off the Big Horn Mountains near Sheridan, WY. We abruptly pulled off I-94 and abandoned our 6-hour pursuit to North Dakota. This was the big turning point of the chase... the quick decision to go after this secondary target that was much closer to us... with much less stress involved.
We sat in Baker, MT for awhile monitoring obs and satellite. More agitated Cu was developing near Sheridan and it became more and more probable that this is where we needed to be... or at least immediately downstream of this area... so we set our sights on Alzada. We drove south admiring the beautiful terrain and even stopped briefly for some landscape photos near Albion before continuing on with the chase. A quick gas stop at Alzada and we were on our way. Some nowcast support from Matt Crowther was helpful in determining our route. A storm was rapidly developing in front of our eyes to our west-southwest. We decided to go due west on a gravel road (Ridge Rd.) several miles. It didn't take long for us to start seeing structure. We pulled off at a relatively high spot and admired the beauty in front of us. A barrel updraft became better established with a long beaver tail to the north feeding into the updraft. Our surface winds had a northerly component. The real-time motion in the updraft was just incredible. You could see the rotation real-time with the corkscrewing action in convective elements of the updraft. The character of the storm was on the dry side of classic on the supercell spectrum...but eventually, as we traced our steps back west, the storm would become more low-precipitation (LP) in appearance and would take on some of the most impressive LP supercell structure I've ever seen! The storm was moving east-southeast and we had to get back east to Hwy 212 so we could continue to stay ahead of it. We stopped a couple times on the highway north of Colony admiring the sculpted beauty. The blue sky behind the storm and the small precipitation shaft made for perfect photography light/color contrast. No words can describe the sight! We ultimately made it towards Belle Fourche, and the storm took on a different character again... looking more classic in appearance with a larger base. We shot more photos at a pull-off between Colony and Belle Fourche and learned of the gigantic hail the storm was producing... softball and grapefruit size hail!! Fortunately, we didn't experience that as we stayed just far enough ahead of the updraft. The storm took a downhill trend as it moved northeast of Belle Fourche and we decided to head back west again after our final stop-off just northeast of town.
We went back northwest on Hwy 212 after we learned of new storms forming in the same exact location as our original supercell developed. (Thanks Dave Ewoldt!) Unfortunately, low cloudiness was increasing and obscuring our view as a strong cold front was pushing south. We decided to head back to Belle Fourche or Spearfish for the night...however on our way back, we learned that a supercell had rapidly formed again from that new activity... but we just couldn't see what was going on given the low clouds. Nevertheless, the storm was moving straight for us and we decided to mosy west on I-90 to see what up. We got as far west as Buelah a couple miles into Wyoming. We noticed impressive anvil zits with high-frequency in the few holes in the stratus... it's a shame the low clouds were as bad as they were. The lightning photography was really a bust from this storm. Eventually, we made it back to Belle Fourche again for the night after being chased to Sturgis by the supercell complex.
Again, what a day! Thanks again to Matt Crowther and Dave Ewoldt for nowcast support in our non-internet areas.
Photos below... a few more on my blog
