Storm Chasing

I’ve had a dream since the age of about 10 and last year this dream became a reality as I hung out of the side of a 4×4 screaming in fear and excitement into the core of a mean looking supercell storm. Last June was my first experience Storm Chasing on the Great Plains of the USA and after 3 weeks there, I’m now completely hooked.

Supercell, Colorado.

Tornado Alley is the perfect place for this magic happen due to its topography and geographical situation. The Gulf of Mexico provides a source of warm moist air which is undercut by the cold dry air masses flowing down from the Rockies and Canada. This creates an unstable atmosphere in which the warm moist air is lifted to its condensation level and intense thunderstorms can form; add changes in wind direction with height and you have the all the ingredients needed for tornadic activity. May and June are classed as the peak months for such activity, and within this period, the conditions needed for the supercellular storms tend to migrate northwards with the jet stream through tornado alley, which itself spans from Texas up to North Dakota on the Canadian border. Due to our June departure date, we envisaged spending quite a lot of the time chasing on the more Northerly Plains which have relatively poor road systems compared to the south, and not as many Wi-Fi hotspots, but the benefits come from some spectacular scenery and much less chaser convergence (storm hungry chasers blocking every viable route to get a storm – seriously, it happens!).

My boyfriend Tim and I flew into Kansas City Airport on 4th June 2010 where we picked up what was to become our faithful Ford Explorer. Along with the rented Explorer, we took in total 2 laptops, radar interpretation and navigational software, a GPS receiver, power converters, data rental cards, wires, more wires, a Nikon, a Canon, 5 lenses, our eyes and 6 months worth of self-taught knowledge on how to best witness these storms, mostly gathered from valuable sources such as www.stormtrack.org and www.convectiveaddiction.com. Prior to our trip, responses from friends and family fell into 2 categories – those who thought it awesome and those that thought us nuts.

There are plenty of tour groups that offer a similar ‘holiday’ package. With experience on their side, being part of such a group would more than double our chances of seeing something, but at prices more than double our budget. We therefore decided to chance it solo, seeing it as an adventure. To avoid disappointment, we kept our expectations realistic. We knew the chances of actually seeing a tornado on a first chase trip is rare but we knew there would be thunderstorms a plenty, huge rotating wallclouds, stunning scenes illuminated by lightning and softball sized hail; Mother Nature at her meanest, and also most beautiful. It wasn’t going to disappoint.

Due to our night arrival to the States, we pre-booked a motel for the night but we were up early the next morning to set up our chase vehicle. Our GPS fed into internet and satellite radar interpretation software, along with our navigation software. The internet based radar data (via GRLevel 3) was higher resolution with many configurable parameters while the satellite radar data stream provided backup for when the internet went down, inevitably during the most intense storm periods. Talking to those who have been actively chasing for over 10 years gave us an appreciation of how lucky we are to now have such technological luxuries for chasing. 10 years ago an experienced eye and maybe trailing sand through your fingers was all you had to go on. That said, there is still an art to interpreting this data and an obvious time when the equipment should be left for gut feeling and taking note of what you are seeing around you. This could not have been drilled into us more before we left and is both key and more rewarding.

A screen shot from our satellite radar software. Our vehicle is the white van in the middle of the clustered storm cells. Arrows represent the stormtracks and the circles are identified areas of rotation based on the software algorithm.

The Storm Prediction Centre’s outlook was our first point of call each morning. They issue a convective outlook to a 3 day lead time. This enables you to focus on an area of interest with severe weather risk zones categorized into Low, Medium or High. It does not end there however as these risk zones often span numerous states. We pinned down target destinations through the use of analysis and forecast data from a number of models such as the GFS (Global Forecast System), the NAM (North American Mesoscale Model) and the RUC (Rapid Update Cycle). It quickly became part of our morning routine to scrutinise the models and independently pick a target destination; then confer and hope we roughly agreed! It was not long before the close shaves or bust days fast tracked our desire to learn from experience and led us to think along the same lines.

The third day gave me my first shocking experience. No matter how many thousands of images I’d seen, or books I’d read, it did not prepare me enough for what I saw. Many people admire these storms from afar whilst many others like to get right into the thick of it. To be honest I went out there not really knowing what I wanted; we were just going to chase storms! I didn’t think about to what degree we would chose to do this. In this case however, the choice wasn’t mine, it all happened so quick. Being new to the game when we saw our chance of getting up close and personal, we just went with it, obviously erring on the side of caution but we still drove in a direction that most sane people would drive away from.

Shelf cloud on leading edge of storm.

Before the holiday, I had read a great deal, but you can’t feel wind from a book and you do not get peripheral vision from a laptop screen. I’ve heard tornado sirens on tele but I didn’t know they sounded like THAT; screaming at you to get out of there. We were on the outskirts of Bridgeport, a small town in Nebraska and coming towards us was a formidable wall of blackness. Out of the car taking photos, I thought we had much more time to getaway than we did. Some other chasers at the side of the road jumped back into their cars and sped off. Before we knew it the rotating mass of thick black low cloud was upon us accompanied by a sustained wind so strong you could hardly even close the car door. And where it wasn’t black, it glowed an eerie green. The wind was deafening and the storm appeared to be encompassing the car from both sides, like a horseshoe, growing and enveloping us in darkness. It looked so alive and so angry.

Manifestation into high precipitation supercell, Nebraska.

We kept on the gas for a further 3 miles amidst a multitude of other chasers and research vehicles, before we could safely deviate away from the path of the impending storm. By this time, the storm had become what is categorised as a high precipitation supercell and any potential tornadoes would likely be rain-wrapped and obscured and lead to much more dangerous driving conditions. This marked the end of the chase and time to concentrate on positioning for the next day, but not before the statutory evening lightshow available from behind the storm as we tracked it in it’s wake.

Lightning illuminated the power of this storm, as can be seen by the notably strong updraft.

The structure on these storms was incredible but well remembered will be Day 14 – the day we saw our fist tornado! It was a good set up; plenty of moisture, scorching temperatures and enough wind shear at the required levels conducive for tornadoes. After a bite to eat we headed across the state border into southern Minnesota. Updrafts were notably strong, a good sign, but the scenario was not without complications. The storm cells ahead of us, rather than remaining discrete were merging into more of a linear formation. We had experienced this on previous days and it is imperative to stay ahead of the line. It wasn’t so simple today though because about 50 miles behind us another line was starting to form, so we may have been the wrong side of one, but we were the right side of the other. We decided to head south to catch the tip of the next approaching line of storms. It is often the case that the southernmost part of the line is where the ‘tail end charlies’ can be found – tornadoes that form at the end of a line of storms, escaping interference from other developing cells behind them.

As anticipated the tail started turning. We raced along the highway to get a bit closer, then off the highway and onto some smaller roads. Good navigation skills were needed here and a feel for exactly where the tornado would be most likely. This is the time for eyes! Rotation was apparent and in the distance we could see a funnel starting to form. It got lower and lower and the dust started swirling from the ground upwards as we had seen happen a few days prior to this. Then touchdown. It was on the ground. Our first tornado. We rushed to grab cameras, memory cards, tripods etc. Nothing was where it was meant to be. We managed to get a few blurry photos but it was hard to not just stand there and watch it. Tim caught it on video and we got a few more pics as it lifted.

Tornado from Minnesota outbreak, June 17th 2010.

In total, from the 22 days we were out there chasing we managed to find bad weather on all but 2 days. It was the second most active June on record since 1950 so we couldn’t have been luckier. We gambled with the weather being bad and it didn’t let us down. So, 11,700 miles later with 2 tornadoes in the bag and a whole lot of storms, scares and thrills we flew back discussing the plan for how we have to do it again this year!

We religiously updated a blog on a daily basis whilst out there which can be accessed via the following link: http://blog.aheadintheclouds.com. Else, if anyone, anywhere, anytime wants to talk about anything storm related, please come and find me!

Cammie

Some more piccies for eye candy:

The green appearance of a hail core, Oklahoma
Rainbow and towering cumulus congestus, Wyoming
Turbulent and wind-torn underside of shelf cloud, Colorado
Characteristic inflow tail from a low precipitation supercell, Colorado
Rotating wall cloud - marked area of primary and strongest updraft. Unfortunately this didn't develop into anything tornadic and rose back up to the cloud base. Colorado.
Positive lightning strike, Texas
Backside of a shelf cloud, often referred to as a 'whale's mouth' based on appearance, Minnesota

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