Storm chasing tours range from 1 to 14 days but the most common amount of chase days are 6-7. So, how many chase days are enough when you go on a storm chasing tour? Generally speaking, the answer is: The more, the better! Storm chasing is a numbers game and it is ALL about probabilities – there are no guarantees. If your goal is to see a tornado you need to get the odds on your side. You can do this by going with a great tour guide, choosing the right time of year and by going as many days as possible.
First of all, every day you are out chasing is a day that will increase your chances of seeing a tornado (or supercell). Think of it as rolling a die and scoring a 6 means seeing a tornado. The more rolls you have, the better your chances are. This is probably the most important ingredient in your recipe of seeing a tornado. You are probably more likely to see a tornado on a 10 day tour with an average tour guide than on a 5 day tour with a great one.
The reason going on a longer tour is important is not only a matter of “every day gives you a new chance”. It is also a matter of surviving bad weather patterns. The weather in Tornado Alley comes in patterns of high pressures, low pressures, jet streams, moisture returns etc. Usually, it is a wave pattern where you will have a few good days followed by a few bad ones. Considering any given geographic location in Tornado Alley you have more bad days than good but since the tours always move to the best location you have much better chances of consistently finding the best ones.
There are however weather patterns that kill the entire region such as ridges (sometimes called “Death ridges” if they are large and lasting) or crashing cold fronts that push all the moisture back to the Gulf. These could make it impossible to find a thunderstorm althroughout the Plains for days. Just before or after (and sometimes under) weather patterns like these you can find pockets of possibilities for storms, so called mesoscale events, but they could be few and far away. Should you go from Texas to Minnesota for a marginal possibility of a storm?
If you are really unlucky you have booked your tour and arrive in the beginning of weather pattern like this and leave just when a new pattern comes in. You can also be lucky and arrive just when a negatively tilted trough is moving in over a moisture saturated Oklahoma with a perfect dryline in place where you can almost guarantee tornadoes!
The conclusion is, the longer your tour is the better your chances are of seeing at least one good pattern during your tour.
If you go on a 5 day tour and arrive into Oklahoma City it doesn’t matter if you have timed your tour perfectly with an amazing setup if it is in South Dakota on your first chase day, or on your last chase day – as you need to get there and back in time for everyones flights. Tour base cities are picked in accordance to where the weather is expected to be the most interesting but there is no guarantee that early May will have storms only in the vicinity of Oklahoma City!
In addition, it is not rare that the first and last day of your tour will account for traveling, more or less. If storm initiation is at 4 p.m. on your first chase day and you leave at 8 a.m. you have a limited region in which you may chase on that day. This is of course a reality on any given day but you can plan ahead better for Day 2.
This question is interesting to know but difficult to answer. Tour companies can claim to have seen 30 tornadoes in May but this does not mean that they have seen a tornado every day in May. Tornadoes tend to come in groups and it is more common that you see another tornado on a day where you have already seen a tornado than that you will see one the next day! If the atmosphere is primed for tornadoes you can see 5-10 in a day.
Thus, “Tornado days” are a more interesting value to compare. Since tour dates are picked way in advance I would say you have a chance of a tornado day somewhere in the vicinity of every 8-10 days (based on my own experience). Thus, in order to have at least one tornado day you need to be out for 8-10 days to be able to expect one.
Supercells are, of course, more common than tornadoes and you can expect to see supercells far more often than tornadoes. My estimation would be on average every 2-3 days. Having mentioned that, even if you don’t see a supercell or a tornado there are a much more that can be incredibly fascinating during a storm chasing tour, such as lightning, shelf clouds of MCS-systems, strong winds etc.
The amount of days you chase is also dependent on when, during the season, you chase. Chasing in April or July is different than chasing in late May. It is a matter of weather patterns and in May you are likely to have quicker shifts between different weather patterns than later or earlier in the season. It is also more likely that you will be chasing in a more limited region (Oklahoma, Texas, Kansas) than later on in the Season when you chase the Northern Plains and storm setups are geographically further apart.
Because of this, most tour companies tend to adjust for this by having longer tours in the beginning and later on the season. Some do however offer a long 10 day tour in the Prime Time in order to have a “Best tour”. This is usually the tour that sells out first – for good reasons.
If you do not randomly pick the dates but go on a On-Call Private Tour your chances are quite different. For these tours you only get out if the atmosphere is likely to produce severe weather and possibly tornadoes and have a much better chance!
The biggest reason for NOT choosing a long tour, however, is that it gets costlier the longer you chase. A 10 day tour will off course cost more than a 7 day tour by the same tour company. In addition, every day out on the road means 2-3 meals in restaurants plus snacks to pay for. Storm chasing tours are expensive and you will have to set the limit on how much you want to spend to boost your chances.
Going on long tours can also be very tiring. You may spend 6-10 hours a day in a van and your back will become sore. If there are no storms around it will get boring and frustrating. You may end up wasting thousands of dollars on a very expensive road trip with no storms. But, as mentioned, storm chasing is a numbers game and you won’t know until you know!
If you have the chance, my recommendation is to try to go on a 10 day tour – especially if you are chasing before or after May. 6 or 7 day tours are perfectly fine (especially in May) and offers a good trade-off in terms of cost and chances.
If you go on a 5 day tour or less, you will really limit your chances and it is down to luck. If this is the only option you have in terms of vacation days and budget, so be it, at least you will be chasing and you have significantly better chances of seeing spectacular severe weather than if you stay at home!
Cloud 9 Tours, with the highly renowned tour guide Charles Edwards, offer 14 day tours by default and their price per day is usually hard to beat. If you have the time and budget ($3.100 as of 2020), this is possibly your best “tornado chance per dollar”.