Uncertain Prospects

18z MLCAPE/MLCIN and 10m wind

Usually by early afternoon on a storm chase, I have a fairly good idea about where I’m going. It’s not always a slam dunk, but usually there’s a target in mind and reasonable confidence in what will transpire. Today is not so easy.

The chaser-favored target is northeastern Colorado, where the Storm Prediction Center (SPC) has issued 10% tornado probabilities. It’s the first time in over three weeks that a 10% area has been issued anywhere in the Plains. With that said, the area is struggling with low clouds right now, limiting boundary layer heating. To make matters worse, forecast model simulations show messy storm modes.

It is Colorado and there are two main factors that make that area an arguable chase target. The first is seasonably substantial low-level moisture and favorable shear. While there very well may be a few tornadoes in the area, it seems fairly unlikely that an outbreak will occur. Furthermore, any tornadoes may tend to be short-lived and relatively low contrast.

Colorado is ruled out.

Northwestern Kansas definitely looks intriguing. There is a leftover outflow boundary in place and areas south of the boundary are rapidly destabilizing. At first glance, it looks like another solid choice, but storm modes here may also be an issue. With multiple boundaries in place and rapidly eroding convective inhibition (CIN), storms may be too numerous and lead to mergers, meaning limited potential residence time for any robust supercells.

Farther south in western Kansas, the story is similar. While the dryline is the only clear boundary for storm initiation, storms here may also grow upscale rather quickly, limiting the potential for any longer-lived supercells.

Kansas could go either way, but it’s a broad target.

Earlier today, the Texas panhandle looked like the favored sleeper target. Aside from few chasers focusing on the area, a greater likelihood for discrete storms could result in a tail-end charlie event, where one or two intense supercells remain fairly isolated and gradually work into an area with better moisture and an increasing low-level jet with time. With that said, “panhandle magic” seems conditional at best, if not increasingly unlikely with time.

The area may be too far south. The best large scale forcing will be focused across Colorado into western Kansas, meaning that the panhandle is only glanced in the upper levels. This could be a net positive, but there’s a catch. The most favorable low-level moisture may be displaced too far to the east, closer to the eastern portion of the Texas panhandle and western Oklahoma. The result is that while isolated convection is still possible along the dryline, any storms may struggle to intensify and/or last for more than an hour or two.

Overall, the day has a lot of potential for a variety of reasons. Colorado could see a multiple tornado day in the northeastern part of the state. Boundaries in northwestern Kansas may light up. The dryline could still produce at least a few brief supercells farther south. Low-level winds are fairly strong, which has not been the case in many High Plains severe weather setups this spring. Boundary layer moisture is also better than most recent events.

As has been the case in just about every setup so far in 2018, while there are some positives, red flags cast uncertainty on just how “big” the day will be.

For now, I will hang out in windy Liberal, KS, waiting to see what direction I may need to go in a few hours.