Severe Weather 2011 / 2012 SeasonUSA Chase May 2011

Distance driven today: 916kms | Total so far: 7308kms

Wow, what a day! Today really felt like our first proper US storm, and it couldn't have come soon enough.

Ponca City in N Oklahoma was our launching point. The target area was W Kansas / E Colorado, so we had another good drive ahead of us.


Some odd 'frontal' type cloud formations dropped some virga and possible light rain. They were like tiny little gust fronts without storms behind them:


Thickening cloud was a concern through S central Kansas:


But the situation improved as we headed W:


Some more odd-looking clouds... these ones more lenticular:


Continuing W towards the Kansas / Colorado border:


Today was a marginal day for storms so thickening clouds was not a welcome sight:


We finally crossed the border into Colorado and stopped at the tiny town of Holly:


A cell was now firing NE of Denver a few hundred kms to our NW with lighter rain slowly increasing along a line to its S. We figured this main cell was probably too far for us, so we continued W in the hope the southern end would fire up.


Things were looking a little chumpy, even at our weaker end of the line, so I was keeping a very keen eye on it in case it strengthened.


Once we hit the southern end of the line, we diverted N towards the main cell in the hope we'd arrive before it died (while staying close to the line). My success with previous endeavours in this regard has been limited!


Facing back S:


We finally got close enough to appreciate the main storm. It had well and truly anvilled and was starting to look a little exciting with mammatus now visible and the sun almost ready to peek out from under the base:


While I was reluctant to head away from any base features at the front of the storm, I was really looking forward to getting on the western side where it would be lit by the full glory of the setting sun.

Just to explain, US storms act a little differently to Aussie storms in more ways than just their size. Similar to SE Qld storms, these generally move NE, but the power of the mid level jet here tends to push light rain ahead of the storm, making it a bit more difficult than at home to get a decent view of the front. I'm really only speaking from little experience at this point, but that's what I've found so far. The back of US storms have a much more defined line on radar (I'm used to the front being more defined), making me keen to be behind this one. Having the sun on that side as well was a definite bonus. I do still wonder though what the front might've looked like. Hopefully this curiosity will be satisfied at some point before we leave.

The other benefit of being behind is that you chase the storm rather than the other around, which gives some breathing space.

Anyway, we continued N towards the main cell as it was visible on radar. With absolutely no rain visible in front of us at all, we suddenly started getting pelted with golf ball sized hail! Where on earth was this coming from? This was really unexpected and threw me a bit. We did a quick U-bolt and it only took 100m or so to get out of it. Then a few seconds later more stones fell and we continued a little further until they stopped.

We pulled over and found that a small foot of the main north-south line tucked westward just a fraction close to our location. The radar showed nothing severe, hence my lack of suspicion. The hail must've only just started falling there, so it wouldn't appear on radar for another six minutes (due to the radar delay on the National Weather Service web site).


Here we got to finally appreciate the incredible colour from the setting sun splashed over this increasingly impressive-looking storm which was tornado warned several times!



The northern end of the line had spectacularly anvilled, with the southern end continually developing and feeding into the line.


The sun soon left us, emphasising the frequency of the lightning, and also making it easier to photograph.


Our plan at this point was to continually hug the back of the storm and stay as close to the lightning as possible without entering the rain curtain. So we choofed off a little closer to it while lightning photography was a bit restricted by the ambient light. We stopped a few kms ENE for an incredible light show:


Mammatus was visible during the constant lightning flashes. I should make it clear that none of these shots are composites!


Some of these CCs (cloud to cloud lightning) were as good as CGs!


I was really impressed by not only the frequency but the punctuating nature of these ground-fearing forks. It was like watching a giant arcing plasma ball in the sky.


As the storm drifted off, we moved a few times to keep up with it. One of these moves was on a major highway with limited exits, so we ended up inside the rain a bit. One of the most surprising aspects of this storm was the lack of visible CGs (even though the CCs were spectacular). I wondered whether they were falling out the front of the storm. But CGs were actually now becoming more apparent and we found a small shelter and did our best to keep the cameras dry.


It didn't take long for the lightning to recede back behind the rain and inside the storm when we finally called it quits about 1am.


Another thing to note is the incredible views from almost anywhere across the Great Plains. This place was made for storm chasers! Heading in your prefered direction without needing to consider the landscape is such a bizarre and refreshing luxury. I don't think I could ever chase in SE Qld again ;)

Now, bring on a frikken tornado!