PERiLS

What is PERiLS?

The Propagation, Evolution, and Rotation in Linear Storms (PERiLS) is an initiative from the National Severe Storms Laboratory (NSSL) to study the behavior of tornado-producing quasi-linear convective systems (QLCS) systems in the Southeast U.S. (wowiee, 3 abbreviations in one sentence). This campaign is set to take place during March and April 2022 and 2023 whenever favorable conditions occur. This will allow us to better understand the mechanics of these types of systems, which can aid in things like forecasting and communicating the social impacts to the population (which is a lot larger in the Southeast than the Central Plains). Read more about it here!

Researchers and students from the NSSL, University of Oklahoma, and other collaborating institutions will join together to collect all types of neat data. I will be on the uncrewed aircraft system (UAS) team server as a ground station operator and a visual observer (depending on what's needed), and we will collect vertical atmospheric profiles during pre-storm conditions. I'm super pumped as this will be the first official field campaign I cross states lines in. I'll update this page like the rest of the campaigns with my adventures out in the field :D

March 17, 2022: Our first deployment (IOP 1) is finally set!

It took a second there, and there has possibly been a little concern about half the month going by without PERiLS data (I'm not complaining though because I'm trying to crank out a paper and will take any downtime Mother Nature throws my way). But it looks like we finally have an ideal system coming through this coming Tuesday! Storms have gone through the Southeast during this past March, but they've been lacking the instability really needed for the kind of storms we want to study. But even a few days ago during our daily noontime briefings, the moisture, CAPE, and wide-open warm sector was notable. It caught the eye of the Storm Prediction Center which issued a 15% risk area on Day 8, which isn't all too commmon. Here's what the current outlook is:

A troublesome trough will make it's way across the Central U.S. moving eastward - I have it postmarked below for Tuesday right after lunch (food is how I communicate time :P). This, along with the high vaues of CAPE, moisture, temperature, and, just for fun, supercell composite in the Southeast is defintely worth the attention. Plus, check out the wind shear in the CAPE and supercell composite models...yikes :o

There's still uncertainties being 6 days out; these models show the ingredients coming together in a classic severe weather outbreak, but much or little this will change with time still in the air (heh). One thing is for sure: the confidence is high enough that the PERiLS team leaders have given the green light for a deployment. So I'll be leaving with my good ole UAS crew Sunday morning! Will we get amazing data? Will the storm's timing pan out? Or will the system be a bust? Tune in next time on PERiLS with Arianna!

March 18, 2022: Updates for IOP 1

There's now a 30% risk area in our domain 5 days out. Oof. On the right is also a rough depiction of where all the PERiLS teams plan to be located, courtesy of Dr. Tom Galarneau. My team will be in Lake Village, Arkansas in the white & yellow circles, making moves wherever necessary. Did I mention I'm a driver? Rest in peace, my teammates xD It looks like we'll be up around 5am gathering observations - such is life in the field! I hope people in this region are being weather aware because I think things are gonna get real nasty Tuesday.

March 22, 2022: Updates for IOP 1

pffffnjnedi3mdek. That's the best way to describe what was a crazy last few days. I'm back in Norman after the very first PERiLS IOP, and I'm beyond exhausted, so my apologies for any poor writing to follow @_@ But I want to write this up while it's fresh in my brain, so I'm going to just jump into my very first out-of-state fieldwork experience!

As mentioned, I'm part of the UAS coptersonde team, and our mission was to fly the coptersonde drone before the line storms came through our domain. We left Oklahoma on Sunday and arrived to our hotel in Greenville, Mississippi about 8 hours later, where we went over the plan for the next couple days. Monday morning, we awoke and performed some test flights. See the video courtesy of Dr. Elizabeth Smith (Twitter: eeeeelizzzzz) for what the test looked like, and pics (courtesy of Tony Segales) of us being adorbs. The coptersonde is being held by one of my advisors, Dr. Elizabeth Smith, on the left.

Note: there's about 18 people in total apart of coptersonde operations for PERiLS, but only 9 at a time were deployed for this IOP. The 9 of us were split into teams of 3 to fly coptersondes at 3 different sites. Unlike other PERiLS teams, our operation was fixed instead of mobile allowing us to co-locate with our CLAMPS trailers (one of them seen behind us with the OU and NSSL logos). For reference, the CLAMPS platform houses an infrared radiometer, a Doppler lidar, and a microwave radiometer to collect long-term time-height cross-sections of atmospheric properties like wind speed, temperature, and much more, so it's been there since the beginning of March. I talk more about CLAMPS capabilities in the BLISSFUL section, but, for PERiLS, the takeaway is to stick with where the trailer is meaning we weren't moving unless it looked like we needed to bail due to a tornado. In any case, it was me and my friends/crewmates Brian and Connor to operate the most westwardly site of Lake Village, AR!

Over the rest of this Monday, we were already paying close attention to the deadly storms making their way through Texas, including me who had a couple friends located in the target area to warn. But we also didn't stay up too long because we had a very early time of waking up at *drumroll please* ......3am. Boy, was THAT interesting lol. We needed the drone up in the air by 5am to collect measurements of the pre-storm conditions before the precipitation came in because the coptersonde cannot fly in the rain. So we might've been a tad sluggish, but somehow Brian, Connor and I successfully made our way from our Greenville hotel to Lake Village and got set-up (and got to wear some stylish vests I might add).

About an hour or so later, we succesfully got 3 flights in the air. The flights are generally quick (about 10-15 minutes if there are no issues), and the plan was to get in about 2-4 of them an hour for the next 8 hours weather-permitting. Buuuut here's the kicker with our particular team: the weather did not permit. Remember how I said the coptersonde cannot fly in precipitation? Well, rain and lightning came after that 3rd flight, and, unlike what we had originally seen from the models, there was no break in the rain. So we sheltered in CLAMPS for the next 8 hours, hoping there would be a break in the rain to get in more flights. Unfortunately, the radar showed a big mess of precipitation pretty much the size of Arkansas itself smack-dab over us, and we knew by 11 am that we were done for the day. Luckily, the other teams to the east were conducting several flights as planned before getting rained out, and one of the teams got some flights in right before a tornado-warned storm came through the area - pretty much the perfect set-up for accomplishing our pre-storm environment science goals! Nothing tornado-wise formed far west enough in our area, which I'm rather okay with judging by how rained-wrapped it would have been. All in all, even though my crew had to be out-of-commision, the coptersonde deployments as a whole were a success.

Despite spending most of the time crammed in CLAMPS, I still had a ton of fun on this campaign. After all, that's just how fieldwork goes sometimes. Things out of your control will happen, and you just gotta make the best out of the situation, which we did by bonding, snacking, playing cards, and best of all: NAPPING! I know the people you're with can make or break a fieldwork experience, and I'm glad to say I thoroughly enjoyed my time with these dudes.

I know the rest of the day was super active for those deployed further east, and I gotta say, watching that multi-vortex tornado rip through New Orleans online was a heart-breaker. It looked like a tornado that should've belonged in the Central Plains. There's still so much about tornadoes, both QLCS and supercellular, to learn about in the Southeast, and I'm glad this research is taking the first steps towards doing that. IOP 2 might start as early as next week judging by the long-term models. I'm not sure yet how much of PERiLS I'll get to be apart of again, since I know deep-down I can't avoid classes forever lol. But I hope I do get to go out again at least once more. Not to mention, Greenville has this seafood restaraunt that is to DIE for. So I'll end with a picture of some delish crawfish, mussels, shrimp, and more *already salivating again.* Shoutout to Old Miss in Greenville, MS!

March 26, 2022: IOP 2 is officially a go!

...I just got home xD

April 2nd, 2022: Updates for IOP 2

I've been back for a few days since my second trip to Arkansas/Mississippi from what I'm happy to say was a very successful campaign, yippee :D In the interest of time for other work I'm currently procastinating on, I'll try to keep this short. The main highlight is my team didn't get rained out this time which allowed for a lot more flights and friends to be made!

This time, my job was ground station operator. I kept track of the data the coptersonde radio-backed to the computer and communicated altitude changes and any errors to the pilot-in-command of the coptersonde, who was Brian from last time (and who was probably sick of being stuck with me lol). Connor wasn't on call this time, so the visual-observer this time around was our new friend, Chad. The 3 of us along with the 2 other coptersonde teams met at the vehicle bay in Norman on March 29th. After making sure all the equipment was accounted for, we drove the 8 hours to our hotel in Greenville, MS, where we made it in time for a beautiful sunset on the Mississippi River! You can even see some leftover gravity waves that were plentiful earlier.

The PERiLS team has monitored the severe weather outbreak that was predicted to unfold the following day for about a week. The moisture, temperature, and wind shear all looked to be sufficient for tornadic activity, and the models depicted this as a line of storms with the risk of embedded rotation, along with a substantially large high wind threat. Unlike the previous week, we didn't have a day to prep before deployment, so we had to be ready to go the next morning. This time, Lake Village was included in the bulk of the threat, so we had to be especially cognizant of the changing weather condtions in the field and plan for a potential place to shelter. Unfortunately, there is a radar hole in this area, so this wouldn't be as easy as we'd like. Below were the issued SPC forecasts for game day...gotta appreciate how the ENTIRE state of Mississippi is in the moderate. At least the hail concern, while there, wasn't as extreme as the rest.

The next morning we had a wake up call of 4 am; only an hour more than last time but an hour I happily cherished. Storms were expected to arrive in our area about 1pm, so our start time was set to be 12Z, or 6 am, to try and get 8 hours of pre-QLCS data. And when we arrived, much to our delight, we saw stars indicating a pleasant clear sky. After setting up and fighting off many mosquito-like bugs (we still don't know what they actually were), we coordinated between the other 2 teams stationed at Yazoo City, MS and Schlater, MS, to fly right at 6 am. All went smoothly with our first flight, and the ones to follow for pretty much the rest of the morning because we didn't get flooded out! *insert triumphant music* Here's some pics of the sunrise near our site along with an AMAZING time-lapse Brian took (Twitter: wxbrain) took that really shows how rapid the low-level wind speed was when clouds actually did start coming in. I also attempted to capture a really nice roll cloud on panaromic though I'm not sure if it came out as cool as I intended.

I don't believe I mentioned this last time, but the specific location we were at in Lake Village, AR was an RV park, so once daybreak hit we got a lot of curious people that emerged from their trailers to talk with us about our work. To tell the truth, I did have nerves in the back of my mind about potential racism-driven encounters that could occur doing fieldwork (no less, flying drones) in the Deep South. While its something that can happen in the field and we needed to be trained on how to deal with such situations, everyone that came up was incredibly nice and friendly; one man offered us coffee and let us play with his dog, Lily! Admittedly...I have more pictures of Lily than the actual operations. But sometimes the coptersonde made it in the pictures/videos so that kind of counts, right?! Here's a few:

So it was hard work + fun times up until about 12 pm. And I lied: we did get some yucky rain move in at that time before the main line, but by then we got basically most of the time period we were looking for, so we could head back to the hotel feeling successful. But not before warning our new R.V. friends about the line of storms that was starting to produce quite a few tornado warnings in down the middle of Arkansas. One other thing about fieldwork that you have to be prepared for is the locals downplaying the situation, but everyone there assured us they'd go to shelter in the visitor's center. It was about a 30-minute drive back to Greenville, and BOY did things get crazy. Look at this mess:

I haven't been in a ton of QLCS situations in my life, but I've never seen that many tornado warnings at the same time for one line of storms. And it was all moving Northeast right toward us. I think the rain was actually a good thing this time because it occured late enough to get our measurements but early enough for us to pack up and head to the hotel, one of our planned escape routes anyway. As it turned out, both Lake Village and Greenville got put under a tornado warning, though Greenville was just at its tip. Luckily, nothing spun up in either area; we did get hit with the straight-line winds but no damage that we could see later. The other teams also successfully conducted their flights and got to safety, and while they also avoided getting hit by tornadoes, one did spin up about 7 miles South of Yazoo City causing minor damage to power lines and trees. Other locations in the line of the path got hit by tornadoes, which can be seen in the SPC storm report below, I also added a video of the storm passing through - it's not super impressive but it clues you in on the strength of the winds.

Overall, everyone this time around got some great data, and this time my team is included! So we celebrated by going to Old Miss for dinner (I certainly did miss it), and saw a nice sunset with scattered scud after the storms went through. The next day was a long drive home, so how else are you going to spend it except jamming out to a hilarious mix of music genres?

That's about it for IOP 2! I won't be on call for the first half of April which means I can take a little breather. And by that I mean work on research haha. I forgot to say this previously as I'm not an avid Twitter user, but check out the PERiLS campaign from the perspective of all the teams at their Twitter account here!

April 29, 2022: PERiLS end for 2022

And that's a wrap!

PERiLS is officially done for 2022, and it was time to collect our two CLAMPS trailers from the Southeast. I got to be apart of the small group of people to do this since it will be necessary for my Ph.D. work to learn how to deploy and undeploy the platforms. So off we went for a last trip to the Delta region (for a while, at least). And it was REALLY short: got there, slept, got up, undeployed. Once each CLAMPS was set up on the trucks we drove up on, we set off for home. Lots goes into readying CLAMPS for travel, in which I'll probably write about in depth in the AWAKEN section. But here's some pictures from the trip both inside and out of the trailer!

There is something I always find laughable about the stares our NSSL vehicles get, such as the one we drove up in pictured first. The meteorological instruments attached to the hood, the hail catcher, and the NOAA logo are more than enough to encite them, but add in our giant CLAMPS trailer in the back and we might as well be the circus! Severe weather was rolling in to our North, so people probably thought we were trying to chase (and in terrible position).

Speaking of which, it was this same day a tragic car accident involving 3 OU School of Meteorology undergraduates unfortunately took place. These students were returning from Kansas after a successful storm chase when their vehicle hydroplaned and they were fatally struck by a semi-truck. It was very soul-crushing to receive this information even if I didn't personally know these students. Everyone in the National Weather Center and the weather community in general is close-knit, so I probably would have eventually crossed paths with them, and I'm sad that won't happen now. I'm glad they got to do what they loved before it happened, and wanted to take a moment to acknowledge what took place. Here is a gofundme page to help with memorial and family expenses.

Anyway, that's it for PERiLS this year! There was lots of driving, early-morning calls, and far too many BUGS. But there also was no end to friendly faces, delicious food, and plently of co-worker bonding time. Time-permitting, I would love to be apart of it again in 2023. But, for now, it's time to gear up for AWAKEN and TORUS. Stay tuned!