Nebraska to Texas and Back again

When I wrote my last post we were in Nebraska, as I write this post, we're in Nebraska again (albeit a different city). However, in the interceding days, we've been to Texas and back. I think the most apt description of this project that I've heard yet came from one of our balloon compatriots from NCAR, who described it as "the magical mystery tour of the Great Plains". Our operations domain extends from South Dakota to Texas, and I figured we'd traverse the whole thing over the course of the 5 weeks that we're out here....I just didn't plan to do it twice in a matter of days : p.

On the brighter side, all of the miles we've been traveling rewarded us with a supercell back on Tuesday (FYI I had to go back to my notebook and first look up which date we intercepted the storm, and then confirm the day of the week....the spiral into temporal confusion continues!). While it didn't produce a tornado it was actually an interesting storm. It was intially a severe multicell storm west of the Dallas-Fort Worth metro area, and there was some heated debate as to whether we should attempt an intercept, as our operations generally call for avoidance of large urban areas at all costs for a number of reasons, not the least of which was that we would have been trying to intercept during the evening rush hour. As this debate raged on, the storm began to show signs of becoming "outflow dominant" meaning the cold air that results from the precipitation falling and evaporating was rushing out ahead of the storm, which is generally bad news for supercell organization and tornadogenesis. Things were looking bleak when the storm began to split in two, with one of the cells taking a hard turn to the left and beginning to head north (referred to as a "left-mover"). This storm developed a region of anti-cyclonic (clockwise) rotation, indicative of a left-moving supercell and appeared to be getting more organized on radar.

While all of this happening, the 4 sounding teams were stretched out in roughly a north-south line to facilitate faster reaction to just this kind of change in storm evolution (the coordinators had yet to pick a clear target, so the sounding leaders had decided to space us out some so we could hopefully respond effectively when they did pick a target storm). As a result, my truck and one of the NSSL trucks were in decent position to move west and deploy on this new left-moving storm. We did so, with my truck getting in position just ahead of the storm to take near-storm soundings on the forward flank (we ended up making 2 soundings) while the NSSL truck moved further north to sample the inflow environment. Eventually the other NCAR truck was able to get in position as well and get an additional sounding off. Making matters even more interesting, between the two soundings that my truck launched the storm transitioned from appearing to be more of a left-mover with anti-cyclonic rotation, to taking a turn to the right and developing a region of cyclonic circulation more like a traditional supercell. This could prove to be a very interesting case to study once we get back. Unfortunately, given our position we couldn't get any cool "supercell-esque" pictures, but I did mange to grab a shot of a rainbow before we redeployed from our first sounding location.



After this, we spent the rest of the week either down (Wednesday, in Norman, OK) or traveling (Thursday, to Topeka, KS). We chased some rather weak storms yesterday, here in Nebraska. While they still weren't really the kind of storms we wanted we did manage to do a good job of getting all of the sounding units into position and launching in near-storm mode within 15 minutes of each other, which bodes well for once we actually get a tornadic supercell (note the optimism...it's still "when", never "if" we see a tornadic supercell). We're down again today, enjoying a day in Grand Island, NE and we have several possible plays over the next few days, however they're somewhat far apart so it sounds like there's going to be some discussion this evening over what we're actually going to try for. When you have possibilities ranging from MN to TX over the course of 2 days, you can't really do them all!

The conditions still aren't great for supercells/tornadoes, but at least we've been chasing in areas where conditions warrant a "slight risk" of severe weather from the Storm Prediction Center, which is a vast improvement over what we'd been chasing over the last couple weeks. This past Wednesday there wasn't even a chance of thunder within the entire VORTEX2 domain, let alone anything severe!