Chasing Storms Saturday May 5th
On the 5 year anniversary of my first tornado, a chase setup along the NE/SD border will present itself. The setup holds some tornado potential, but it is not the best there can be. Directional shear looks great, but speed shear and upper support are lacking. In addition to this, some model runs have been showing extreme CAPE value exceeding over 4000 j/kg, this makes me wonder if a squall line will be quickly forced up as opposed to more discrete supercells. Still though, with the good veering of height in place any storm that goes up and remains discrete, especially early on will have a chance at a good tornado. A stronger cap could help keep a lid on things and promote more isolated development as opposed to a gigantic mess going up all at once, at least that is the hope.
Even if tornadoes end up being scarce, there should be plenty of big hail to get into and structure to be had in wide open terrain. The current plan is to stay somewhere around Sioux Falls and target along the SD/NE border area south of I-90. Right now I think South Dakota looks a little bit better than Nebraska for the fact the better mid/upper support is there as noted by the sfc-500mb bulk shear values.
The NAM shows the cap being a little stronger in this area though, which could be a good/bad thing. Too strong and it wont break, stronger (but breakable) than areas to the south, and being closer to the warm front could promote a more isolated storm mode, whereas linear forcing coupled with extreme cape in Nebraska would favor a quicker linear evolution, at least initially.
A popular index chasers like to look at is the EHI, this will probably have more people scurrying to the SD play, since values of 3 or higher typically yield better tornadoes. I am no different in this regard.
No matter how you slice it, the chase day looks solid and is worth venturing out for. It is not inconceivable that a slow moving CAPE monster supercell can find some mesoscale boundary and drop a nice tornado given the parameters in place. Storms currently ongoing in the area could leave remnant outflow boundaries that serve as a focal point for new thunderstorm development, and can also enhance local SRH values. This area is notorious for these types of storms, especially in a very summer like setup which is what we are presented with for Saturday.
Once challenge I am not looking forward too is navigating around the Missouri River, that is always a concern not only for lack of road crossings, but typically terrain gets worse around the river valleys, so hopefully the storms pop far enough away from those areas.
Stay tuned for the live stream!
