The University of Manitoba 2017 storm chase trip weather imagery
Overview
After a little bit of work, I have compiled imagery from the storm chase trip. For each day, I will repost the blog entry about that day's chase, and then I will have upper air maps, satellite imagery, and RADAR from the day.
Day 1: June 26, 2017
We started the morning in Kearney, NE, with our initial target of McCook, NE. We had decided on a target area of eastern Colorado, northwest Kansas and southwest Nebraska.
Along the way, we noticed morning ACC (altocumulus castellanus), which is a good indicator of midlevel instability. Also, when we were on the drive, we noticed (via RADAR and visually) some thunderstorms going to our north and northeast.
We decided to stop and have a look at the storms that were going on, as there was no other action going on in the region of interest. It was clear that those storms were elevated, as the mushy appearance in real life and disorganized reflectivity on RADAR showed.
Storms still kept going and started to intensify generally to our north, all the while building westward along the slowly-advancing cold front.
At this point, 2 of the 3 vans lost their internet connections. It made a chase day all the more difficult and stressful, but we managed.
One storm then began to dominate, one that was a little behind the initial broken line but still ahead of or along the cold front. We decided to stay put and see what it would have to offer.
As we refined our location relative to it, we started to see some structure--a wall cloud, mostly. Some good ventilation aloft was evident, as well.
The storm then quickly really became rather mean. It showed us alternating low-level outflow and inflow structures, so we were in inflow at one moment and in outflow at another; the outflow was rather chilly and wet, but the southeasterly winds into the storm complex told us that the storm wasn't done.
We were stopping and taking pictures, then driving a little west as it surged more outflow south and a little west. Eventually we came to a town where we could cross the Platte River and chase not just west but south. This was a great option for us, as the southward reach of the storm was latitudinally equal to our location. We got south and then got west just ahead of the outflow, hoping to see something good. And see something good we did: we stopped just short of the best gustnado I've ever seen. It was a long-lived compact vortex of wonder, awesomeness and dust. It last for about a minute, maybe a bit more. Justin's video even got picked up by The Weather Channel.
After the gustnado, we were a little jazzed up but ready for more. We got going west some more and we turned onto another road, a rained-on dirt road. Not the best idea, as we immediately started sliding as though we were on ice. Oy. Justin stopped and we advised the other vans *not* to advance on this road. Justin then put it in reverse and (rather heroically) inched backwards approximately 100 metres back to gravel. There were a few times we were close to sliding off the road, but Justin kept that from happening. (Thanks, Justin.)
The storm we had been watching (we in Chase 1 called him Gus) started to decay a bit--his outflow pushed way ahead of his inflow, and the updraft shrank considerably. A beautiful hail shaft was its last gift to us as we decided to move west to catch another storm.
This storm was another one westward along the line, but it decided to get outflowy too.
We went westward to an interesting-looking storm that was dropping south, one that was tucked well northwest of our location. As soon as we saw it, though, we knew it was pretty special.
Boy, were we right.
We got a little closer to the storm and decided to take a dive south so we could see it better; a navigation error meant that we missed our turn-off and had to turn around. Well, at the turn around near some grain silos, we stopped and got out to take some pictures.
This is where the storm decided to show us some great stuff. The lazy low-level rotation tightened up really quickly. It was strongly ingesting air, with help from some modified outflow from the storm to our southeast--it was raining into our updraft region. I think that this storm was actually helped and hindered, simultaneously, by this rain. It cooled (stabilized) the inflow region and moistened (destabilized) it, making sure the updraft base was lower. It was ingesting surface-based parcels or near surface-based parcels, and the base looked to be below 1000 feet AGL. Then, the rotation got focused in one region and (I'm not kidding) we were all chanting "GO GO GO" at the storm; this was as close to producing a tornado as I've ever seen a storm be without actually producing.
After a while the low-level rotation weakened substantially but the broad-scale rotation was still good and so we decided to drop south with the storm, knowing that this was the storm to be on.
As we went south, it continued to show us HP and classic looks, with scary hail cores evident and then good updraft areas prominent.
We kept playing with the storm, as it was showing large to very large hail, so we stayed out of its core (for the most part). We stayed back for a bit and tucked in behind the storm to see how big the hail was along the side of the road, and we got hail that was, at its largest, quarter-sized. We notified the appropriate NWS office and went on our way. Moving southward through the hailfall we encountered another neat phenomenon: hail fog. It was pretty neat and eerie to see.
Finally running ahead of it, the storm decided to give us its last look. It quickly morphed from a scary HP to a stunning LP supercell and it was so quick that I couldn't quite believe what I was seeing. All of a sudden we were seeing striations and a huge separation of the updraft from the precipitation core. At the same time RADAR was showing a marked increase in the hail size, despite it looking rather transparent visually.
A sheriff stopped to talk to us for a while. He was extremely friendly and seemed to want to share his stories.
Eventually the LP structure started to decay, and it was time for us to get some fuel, both for our vehicles and for ourselves. We stopped at a gas station where the storm gave us its last hurrah; it was severe-warned as it moved over us in Scott City, although the hail we eventually got at the gas station was about pea-sized, no more. A little wind made the rain rather horizontal, and then that was the end of it.
Dinner was at a down-home place called Tate's; wonderful large portions of good food and friendly service. I would recommend that any day of the week.
We had our overnight in McCook, NE, in eager anticipation of the next day.
Day 2: June 27, 2017
Tuesday was an interesting day with a lot of potential, although some weaknesses in the upper flow were evident. We targeted the NE/CO/KS border.
Morning moisture was pretty good, with lower 60s (F) aiming for the area. Storms were suppressed for a while so we were able to get lunch in Sterling, where it was really hot (38 C) and the Verizon people were unable to help us with our jetpacks.
Cumuli started bubbling up in southeastern Wyoming, and eventually some storms morphed out of that. We drove northeast into the Nebraska panhandle, watching as the storms became a sort of north-to-south broken line. A lead cell went to our north and we jumped ahead of the line to be in place if that storm took over, but stayed far enough south so that if tail-end Charlie took over, we could target it, too.
The lead storm didn't change much, so we drifted back south to see what the one on the south end of the line would do. It was a nice shelf with some curvy rain curtains coming out of it, but further storm organization looked unlikely. So we moved east and then north, passing by an air force RADAR on the way to our hotel. The band of storms approached us as we were just south of the hotel, it got severe, producing wind gusts in excess of 100 mph to our north. It hit us at our gas stop with some pretty strong winds, although I don't think they were severe at that location.
We got pizza in the lobby and had a good evening by the fire.
Day 3: June 28, 2017
Wednesday was a day with 2 potential locations to chase and another that we knew would light up but wasn't reachable. The two locations were eastern Colorado and southeast Nebraska. Eastern Colorado was a lesser play because the moisture had been flushed, so we opted for the southeast Nebraska play.
We were expecting primarily outflow-dominant supercells because the models had been consistent in veering the winds ahead of the slowly-advancing cold front. But a detail in my H5 analysis gave me hope: there was a subtle thermal ridge/trough couplet over Nebraska that the model hadn't picked up on. So if it would time favourably, perhaps pressures would fall and winds back at the surface, giving us a better tornado chance.
After lunch in York we came outside to see significant towers bubbling up to our east. Visible satellite imagery also showed an area of significant agitation in the cumulus field over the area, so we hurried in that direction. Once we got east of Lincoln, towers were really starting to show great vertical development, and one looked like it had breached the cap near Nebraska City. Soon it became a full-blown storm crossing the Missouri River.
After navigating up the bluffs and through Waubonsie State Park, we came to an opening where we could see that the storm was really ramping up its rotation. We stopped to have a look and, around 3:43 PM, we caught the first tornado of the U of M 2017 storm chase trip!
The storm somewhat disappeared into the terrain so we continued east. The mesocyclone decided to produce a very pretty vortex on its edge. We stopped for more pictures and the storm produced a second tornado for us.
After this, the storm got rather messy with new storms going up and interacting with the existing ones, so we looked to our south. At that point we saw a new updraft rocketing up, with amazing motion on a wall cloud. We were in a weird place relative to the storm, one I don't usually place myself in, northwest of the circulation. No precipitation was on our tail, so we had time. The storm really ramped up its low-level rotation and it had the chance to produce a tornado a couple of times, but it never quite focused the rotation enough. After finding a 2 inch hailstone in the grass, we opted to keep following along with the storm until it got messy because of more interactions.
At this point, there was just a big mess of storms interacting with one another, so we opted to drive back to the hotel. We started out north and saw on the RADAR that we would be going through a nasty hail core, so we doubled back south to get around the complex. Also, RADAR showed that somewhere upwards of 8 inches of rain had fallen there too.
We got south and west, and another storm decided to get strong in front of us--bonus supercell! It showed us a nice wall cloud and a possible tornado, but its main characteristic was that it was throwing out tremendous lightning bolts all over the place, and we got some really good pictures.
We got in late to our hotel in Lincoln, so dinner was a quick grab-and-go along I-29.
Day 4: June 29, 2017
Thursday was supposed to be the day.
We outlined 4 areas, all with pluses and minuses. The #1 target was northeastern Nebraska. #2 was southeast CO. #3 was northeast KS. #4 (not chaseable) was around Buffalo, NY.
We got going north to our initial target of Norfolk, as the surface low was very close to there. We had a quick lunch there and came out to see big towers going up to our northeast, right on the warm front emanating eastward from the low.
We followed it along and it grew rather quickly as we approached it. Once its tops reached about 50,000 feet it got severe warned. It even had a TBSS on it.
The storm quickly split and started rotating. As we approached it, we got up on a hill and saw a couple of attempts but it couldn't focus its rotation. We got back on the highway and the storm continued to strengthen, as did its RFD. We had to stop a couple of times a) to watch and b) to avoid the rotation on the storm.
Navigation became an issue, though, as the storm was heading straight for Sioux City. The problem with that is the Missouri River, which has one crossing right there and another about 30 miles to its south. We decided to tuck in closely behind the storm, cross the river and then get ahead of it once again. We passed through some heavy rain and some hail along the way--through Sioux City there were some hailstones that might have been quarter-sized, maybe a touch larger.
As we once again got in view of the storm, it showed us some decent structure but then another storm started to go up to its south. Destructive interference was occurring so (after a flat tire scare) we dropped south to see if the south one could organize. And it did.
The roads, hills and trees made it difficult to get more than a glimpse of the storm, but we could see (both visually and on RADAR) that this storm was quickly organizing. We finally found a good option south of the storm where we could see it, and a glorious scary supercell was right in front of us. It had a fairly round bowl mesocyclone, and a good inflow tail was hugging the ground. It made a few attempts to produce a tornado in the green hue, but (again) couldn't quite focus the rotation.
After that, the storm lined out and then another south one tried. That farther south one didn't do as well and linear forcing was becoming more prominent, so we called the chase for the day and for the trip.
We had dinner at Texas Roadhouse in Sioux City and stayed there for the night.
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Last update to this page: November 8, 2017
