Why Most Storm Chases Fail
Storm chasing has its thrilling moments—when a storm explosively breaks the cap, when you see a stunning supercell, or when a tornado intensifies right in front of you.
But anyone who’s chased for more than a season knows the reality: these moments are rare. Most of the time, you end up busting. Sometimes it’s due to a bad decision, other times it’s a muddy road. But usually, it’s just that the weather in your target area didn’t cooperate.
Recognizing these failure modes is crucial to avoiding them. Doing so can save you a lot of frustration and lead to more successful chases.
Chase failures can be caused by many factors, but most are tied to weather conditions. Even during a major outbreak, just one or two variables can turn a promising target storm into a bust. That’s why it’s crucial to understand which meteorological factors can ruin a chase day.
It's not always easy to pinpoint which weather factor caused a setup to fail. However, based on 25 years of experience, I’ve found that these meteorological issues are often the culprits behind a ruined chase day:
- Too many storms
- A cap that’s too strong
- Excessive cloud cover
Here is an explanation for each failure mode and strategies to overcome them.
Too Many Storms (Upscale Growth)
One of the most common failure modes is having too many storms, known as upscale growth. Tornado-producing storms are usually at least semi-isolated because they create weaker cold pools, which are more favorable for tornado development. Cold pools are areas of rain-cooled air, and the more rain you have, the stronger your cold pool becomes. Therefore, more storms lead to stronger cold pools, reducing the chances of tornado formation.
A classic example is the April 6, 2001, High Risk bust. All the ingredients were in place for a big event, but a line of storms formed too quickly, destroying the tornado potential. On the other hand, if upscale growth is delayed, there’s still a chance to see tornadoes. The supercell that produced the EF4 tornado in Bowdle, South Dakota, on May 22, 2010, stayed isolated just long enough to produce a significant tornado before nearby storms quickly ended the event.
What to Do About Upscale Growth
In cases like Bowdle, you might be tempted to write off a storm early. That’s exactly what my group did that day when I was part of VORTEX-2. We didn’t realize the time window was just long enough to support a major tornado because the environment was so explosive.
Alternatively, consider a situation like the Moderate Risk in Oklahoma and Texas on May 25th this year. The potential for upscale growth was well-known, and we knew it could bust if storms grew too quickly. So, we targeted the southern part of the risk area, anticipating a “tail-end Charlie” storm that could tap into the prime environment. It paid off, and we saw a beautiful tornado near Windthorst, Texas.
Cap That is Too Strong
On the opposite end of the failure spectrum is the dreaded cap bust. These are especially painful because not only do you miss tornadoes—you often don’t see any storms at all, leaving time and money wasted.
Like the issue of upscale growth, a strong cap can usually be predicted well in advance. Chasers often gamble on strongly capped areas, hoping for big rewards if a storm does break through. However, sometimes even when a storm forms, the cap can still pose a problem. For example, on May 8, 2003, a strong capping inversion caused the storm that produced an EF4 tornado in Moore, Oklahoma, to weaken soon after the tornado lifted.
What to Do About the Cap
If the environment is explosive but capped everywhere, you may just have to accept the risk. But if you have an option to target a slightly less explosive environment with a weaker cap, it may be worth considering.
A great example of this is April 23, 2007. Every chaser was focused on an incredible environment near Pampa, Texas. But the storms that developed there ended up being narrow and weak. My chase group and I realized it wasn’t going to pan out, so we shifted to far northwestern Oklahoma, where new development was happening in a less explosive environment. This decision paid off: we observed 7 tornadoes from a prolific supercell near Protection, Kansas.
Excessive Cloud Cover
Having too many clouds in the target area before storms form is another factor that can reduce tornado potential. Thick cloud cover can limit surface heating, which decreases atmospheric instability—a key component for storm intensity. Without sufficient surface temperatures, the likelihood of tornado formation decreases.
For example, on June 12, 2005, near Childress, Texas, my chase group targeted an outflow boundary due to its stronger low-level shear. While shear conditions were ideal, the thick cloud cover over the boundary limited surface heating. Although the clouds eventually cleared and a supercell formed, surface temperatures remained too cool to support a significant event.
Meanwhile, further south along the dryline near Jayton, Texas, the sky had already cleared. A supercell formed in that area and produced multiple tornadoes.
How to Handle Cloud Cover
As shown in the June 12th example, insufficient sunlight in your target area can hinder tornado development. If cloud cover is reducing solar heating ("insolation") at your chosen location, consider adjusting your target. In this case, moving south to the clearer area would have been a better choice.
However, clouds don’t always prevent tornado outbreaks. For instance, during the May 3, 1999 outbreak in central Oklahoma, thick mid- and upper-level clouds blocked sunlight for most of the day. Despite this, high dewpoints created strong instability, leading to a historic tornado outbreak even with lower surface temperatures.
Balancing Risks and Rewards
Choosing between target areas is always challenging, even if you know the potential failure modes in advance. That’s why I believe it’s best to weigh the failure risks against the environmental upside for each area. What’s the best environment? What could go wrong? And am I more likely to see a tornado in the less volatile environment? These questions can help guide your decisions and improve your chances of a successful chase.
