Hook slicing: What do you think?

[Taylor Wright]

I've seen a couple videos of chasers attempting it on the tornadoes today and nearly getting themselves killed by flying debris. To me, moving through the hail core on the north side of a potentially developing (or fully developed) tornado seems very dangerous, and I've never attempted it. I prefer to stay on the southeast side of the rotation. Those of you that do attempt it, how is it executed properly and safely, and have you ever found yourself in extreme danger because of it?

 

[Royce Sheibal]

Had to do this once to get out of the way of the tornado itself which had jumped on me. Aside from that, NOPE. NOPE NOPE NOPE. I like having windows on my car and dry pants.

 

[Paul Knightley]

This term seems to be a relatively new one (and I'm certainly not against the development of jargon, or in a wider context, language) for what has essentially been termed 'core punching' and getting into the 'Bear's Cage' for many years. OK, it may be somewhat more specific than those terms, but the end result is the same. It's something that is best avoided, IMO.

 

[Dan Robinson]

As Paul said, traditionally this has been called "core punching". "Hook slice" is a term I hadn't first heard used until last June after El Reno. From what I understand, hook slice refers to a west-to-east transection of the hook to the north of the meso. Core punching is also a common move from north to south through the forward flank precip east of the meso, done if you find yourself on the wrong side of the storm (to its north).

As to whether or not it is safe depends on the character of the storm. In HPs, no, it is usually not a good idea. For classic supercells with a.) highly visible wall clouds/tornadoes b.) small tornadoes (stopepipes, ropes, cones) (NOT wedges!!), b.) when you have good radar data and c.) when the tornado is still a good distance to the south to where you're not going to be "racing the train to the crossing", it is relatively safe. In a classic supercell, there is usually a very wide gap between the edge of the zero-visibility precip to the north/west of the meso and the tornado, though large hail is common there. A lot of classic supercells will only have a thin band of precip in the hook area to where you can even view the tornado from the west, eliminating the visibility problem. Of course you need to be mindful of occluding/occluded tornadoes which can be rain wrapped to the west of the new meso.

North-to-south core punching through the forward flank precip core is usually safer than west-east with any storm, as long as the storm is moving slowly enough and you can punch through well ahead of the meso. The forward flank precip is usually free of the largest hail. If it looks like you'll cut it close with the meso/tornado/large hail, keep going east until you have enough room to drop south with room to spare.

A strong northerly wind when traveling east through the hook can be a sign that something may be getting closer than you want to be. As long as you are mindful of your position, radar, character of the storm, location of large hail, and wind direction, then you can make a reasonable decision whether or not it's safe to proceed. When in doubt, hold back or approach from a different direction altogether.

 

[mcrow24]

I'm not very experienced with tornadoes but I think it is pretty risky in most any case. You are intentionally putting yourself in a tough situation which from what I understand is not accepted practice. It's one thing to get close and be a in an easy position to escape from but this core punching pretty can pretty easily put you in a situation without any clear escape routes should the tornado do something unexpected (and we know that never happens..).

 

[Rob H]

For clarification: yes, it is the west > east bisection of the hook as opposed to core punching from the north.

how is it executed properly and safely, and have you ever found yourself in extreme danger because of it?

It isn't executed safely, and you're in danger every time you do it. I've done it on Mapleton, Langley, Wayne, Wakita and a few other large tornadoes, and a handful of smaller ones. I do it much less frequently in the last year or two, because I like returning home to my family alive.

Pros:
-It's an efficient way to get very close to a tornado, and opens up another avenue for attack especially if the road network made SE positioning troublesome.
-Very, very rare for a tornado to loop back and travel west, so as long as you don't cross in front of the tornado, the chance of getting directly hit by the tornado is small.

Cons:
-Not crossing in front of the tornado isn't as easy as it sounds
-TWISTEX did it at El Reno, pretty good example of why not to do it. In fact, Tim seemed to prefer hook slicing and the only times I ever saw him chasing was when we were both in the hook. It was likely the easiest way to get directly in the path to place probes
-You're in extreme danger every time you do it, because you're bisecting the bear's cage and aiming right for the bear
-Your escape routes can be limited simply by the storm changing, and no two storms will act the same. "Drive south" doesn't work. I've had to escape north, south, and west before.
-You almost need a partner looking above the car and watching rain/wind patterns around you
-You follow in the debris path meaning that your roads may be blocked, and you're much more likely to come across injuries and deaths
-There's a good chance of driving over wood with nails sticking out
-RFD driven hail can easily take your windows. Wakita was lobbing softballs sideways with 75mph RFD.
-The tornado is moving away from you and your precip-free window is 1 minute tops. No time for tripods or enjoying the storm.
-Rear inflow jets like to take your back window out, especially if you're in a vehicle with more vertical window profiles like an SUV

It's actually easier to do the larger the tornado is. Even on HP storms, there seems to be a ~1/2 mile precip free zone directly around the tornado where hydrometeors are shunted away. I've never been surprised by a large tornado while hook slicing, but the smaller ones (EF0-EF2) can almost come out of nowhere.

The most important part of safety is not ending up in the tornado's path. To do that in heavy precip you have to know your position relative to the updraft, and watch the rain/wind patterns. This isn't something that can really be taught or explained, it's experience gathered from being close to tornadoes. RFD/inflow transitions, inflow jets/the "ghost train" - they're all things that you have to know intimately and watch for. It's easily the most stressful thing I've done while chasing.

As such, the hook slice shouldn't be attempted by anyone without that experience, and probably shouldn't be attempted at all. Especially as this thread is in the intro section. I'm not trying to be elitist or anything, but unless you've been close to more than a handful of tornadoes, hook slicing can be a really bad idea, and even for veterans, it's a risky maneuver.

 

[John Olexa]

This term seems to be a relatively new one (and I'm certainly not against the development of jargon, or in a wider context, language) for what has essentially been termed 'core punching' and getting into the 'Bear's Cage' for many years....

There have been a few new terms used I haven't heard of, or understood there meaning. Thanks Paul, I was beginning to feel like I didn't know squat. Core punching , Bears cage, that I understand! Guess this just means I'm getting old and not keeping up with the times. LOL

 

[mcrow24]

It isn't executed safely, and you're in extreme danger every time you do it. I've done it on Mapleton, Langley, Wayne, Wakita and a few other large tornadoes, and a handful of smaller ones. I do it much less frequently in the last year or two, because I like returning home to my family alive.

Pros:
-It's an efficient way to get very close to a tornado, and opens up another avenue for attack especially if the road network made SE positioning troublesome.
-Very, very rare for a tornado to loop back and travel west, so as long as you don't cross in front of the tornado, the chance of getting directly hit by the tornado is small.

Cons:
-Not crossing in front of the tornado isn't as easy as it sounds
-TWISTEX did it at El Reno, pretty good example of why not to do it. In fact, Tim seemed to prefer hook slicing and the only times I ever saw him chasing was when we were both in the hook. It was likely the easiest way to get directly in the path to place probes
-You're in extreme danger every time you do it, because you're bisecting the bear's cage and aiming right for the bear
-Your escape routes can be limited simply by the storm changing, and no two storms will act the same. "Drive south" doesn't work. I've had to escape north, south, and west before.
-You almost need a partner looking above the car and watching rain/wind patterns around you
-You follow in the debris path meaning that your roads may be blocked, and you're much more likely to come across injuries and deaths
-There's a good chance of driving over wood with nails sticking out
-RFD driven hail can easily take your windows. Wakita was lobbing softballs sideways with 75mph RFD.
-The tornado is moving away from you and your precip-free window is 1 minute tops. No time for tripods or enjoying the storm.
-Rear inflow jets like to take your back window out, especially if you're in a vehicle with more vertical window profiles like an SUV

It's actually easier to do the larger the tornado is. Even on HP storms, there seems to be a ~1/2 mile precip free zone directly around the tornado where hydrometeors are shunted away. I've never been surprised by a large tornado while hook slicing, but the smaller ones (EF0-EF2) can almost come out of nowhere.

The most important part of safety is not ending up in the tornado's path. To do that in heavy precip you have to know your position relative to the updraft, and watch the rain/wind patterns. This isn't something that can really be taught or explained, it's experience gathered from being close to tornadoes. RFD/inflow transitions, inflow jets/the "ghost train" - they're all things that you have to know intimately and watch for. It's easily the most stressful thing I've done while chasing.

As such, the hook slice shouldn't be attempted by anyone without that experience, and probably shouldn't be attempted at all. Especially as this thread is in the intro section. I'm not trying to be elitist or anything, but unless you've been close to more than a handful of tornadoes, hook slicing can be a really bad idea, and even for veterans, it's a risky maneuver.

I'm a newbie but to me it seems like people that do this are a little bit too sure of their abilities to control the situation. Seems to me that when you attempt this sort of thing you are just about at the mercy of the storm. I get the need for the thrill or the great video/pictures but that's a heck of a risk.

 

[Rob H]

I'm a newbie but to me it seems like people that do this are a little bit too sure of their abilities to control the situation. Seems to me that when you attempt this sort of thing you are just about at the mercy of the storm. I get the need for the thrill or the great video/pictures but that's a heck of a risk.

That's probably true. Most of the time when I do it, it's because a road network or hail core has limited my other options and its a last-ditch effort to see the tornado.

edit: It's probably worth nothing that the seemingly innocuous

there seems to be a ~1/2 mile precip free zone directly around the tornado

is more commonly known as the bear cage

double edit: I should also note that hook slicing on El Reno/Pilger/etc are examples of exceedingly poor judgment. I don't think I'd ever hook slice if MLCAPE was more than 3500 or so. As Jeff Duda said in another thread, weird things can happen with extreme instability, and in my mind "weird things" is equal to "things that can surprise and kill me".

 

[Taylor Wright]

Thanks for the responses guys. Some good explanations here. The curiosity first arose when watching a chaser's video of one of the Pilger tornadoes. He had to come within 50 yards of this thing with debris flying everywhere and it's a miracle a telephone pole didn't get lodged through the side of his car or something. I noticed the tornado was moving left in front of him (indicating the hook slice). While the video was one of the best I've seen, I personally don't think it's worth putting your life at risk for.

My biggest fear would not be getting caught by the tornado, but having baseball size hail bust open my windshield with a tornado approaching just to the southwest. But, as Dan and Rob noted, if you have solid radar data and you have a good estimate of hail size, storm motion, and the tornado is in a rather "predictable" environment, (the complete opposite of the Pilger tornado), then I guess it would be somewhat safe to attempt. Something I'll probably hold off on for awhile, or maybe practice on a high-based cell with no massive precip core.

As such, the hook slice shouldn't be attempted by anyone without that experience, and probably shouldn't be attempted at all. Especially as this thread is in the intro section. I'm not trying to be elitist or anything, but unless you've been close to more than a handful of tornadoes, hook slicing can be a really bad idea, and even for veterans, it's a risky maneuver.

I thought about putting this in the advanced chasing section, as it's definitely a maneuver for advanced chasers, but I didn't know if asking about it there would be a good place. Mods can decide if they want to move it.

It's only a matter of time before someone (else?) loses their life from doing this, so maybe it should be publicly discouraged. While everyone is free to do what they want, this forum might be a good place to let the newbies understand the danger from it and to not attempt it, especially with the growth of storm chasing and the increased ability of chasers with little experience to get on tornado producing storms. That is part of the reason I started this discussion up.

 

[Bob Schafer]

Rob, I'm confused. If the hook slice technique is to drive west-east (to the) north of the tornado, then how can it be that "You follow in the debris path meaning that your roads may be blocked, and you're much more likely to come across injuries and deaths", and "The tornado is moving away from you"?

Are you sure you've got this right? It sounds like you're talking about driving west-east AFTER the tornado has passed, and to the SOUTH of it. I don't think that's what is meant by hook-slice, and it's certainly not what Tim, Carl, and Paul were doing.

 

[Jeff Duda]

Every situation is different. Rob highlighted the typical hook slice, but the exact way you can do it depends on the orientation of the features in the storm and the storm's motion. What Rob discussed was for typical supercells moving generally between 225 and 270 with the FFD on the north/east side of the updraft and a precip-laden hook wrapping around the west/south side of the tornado. If the storm is moving in a different direction, you would probably not be slicing west-to-east. Rather, hook slicing means entering through the back of the storm at the hook-echo/RFD merger and basically driving from there to between the forward flank and the updraft region, which is typically where the vault region is. You pop out just downstream (i.e., in the path in many cases) of the tornado.

I did this once (with Tim Samaras in TWISTEX) and it was one of the most frightening moments of my chasing career, let alone life. We hook sliced an east-moving tornadic HP supercell. Thankfully when we popped out, we were still northwest of the tornado, which was about one mile away. The biggest thing I learned from that (other than it's a bad idea), is to watch the surface winds (as Dan mentioned). If there is a tornado on the ground, surface inflow will be markedly increased from winds in other parts of the storm. Also, since these are inflow winds, they tend to blow almost directly into the tornado. In our case, we had steady northwest winds the entire time through the hook, so we knew we were not in the tornado's path. So if you're slicing a typical storm and you have a northwest wind, then the tornado is probably southeast of you. Now, due to friction, the winds don't blow directly into the tornado in some cases, but rather they converge cyclonically, so that the tornado is just to the left of the wind direction. This means if you're hook slicing and you're north of the tornado, beware of north or northeast winds because it means you are probably in the tornado's path at that point.

It's easier to hook slice a storm when it involves a nearly parallel angle between you and the tornado, because that minimizes your chances of ending up in the path of the tornado. It would be a really bad idea to try to hook slice if you were literally trying to beat the tornado to the point where it would cross the road ahead of you. DON'T EVER DO THAT if you lose sight of the tornado for even a second!

Basically the worst part about it (other than ending up in the path) is losing sight of the tornado. It can be executed with more precision if you can see the tornado the whole way through. That still doesn't make it safe because tornadoes are capricious on the time/distance scales involved during the hook slice. Rob already discussed that, and I agree with his thoughts.

 

[Jeff Hawkins]

double edit: I should also note that hook slicing on El Reno/Pilger/etc are examples of exceedingly poor judgment. I don't think I'd ever hook slice if MLCAPE was more than 3500 or so. As Jeff Duda said in another thread, weird things can happen with extreme instability, and in my mind "weird things" is equal to "things that can surprise and kill me".

I love just LOVE getting the comments and experiences of "senior" chasers who both have more advanced book knowledge and experience they can share to help all noobs like me to learn from them. What I gather from Rob H's, Jeff Duda's, Bob Schafer's, Dan Robinson's and others' comments is that basically core punching isn't smart so don't do it if you want to live to chase another day, but if you are in imminent danger and can't avoid it, then you need to pay attention to your immediate surroundings including the wind direction in relation to the storm, to determine what direction to move in. Generally for myself, I avoid being IN storms in the first place unless I know they won't be severe/tornadic. If they are, I try to keep myself at least a mile outside the base if possible. I know I miss 'stuff' doing this but frankly, my life is more important. I've still been able to see several tornadoes doing this, so I'm happy.

 

[Marcus Diaz]

Note to others, don't core punch a SE moving storm unless you enjoy massive hail.

 

[Jeff Duda]

Note to others, don't core punch a SE moving storm unless you enjoy massive hail.

That's a good point and it reminds me of something I forgot to say in my previous post. Sometimes supercells are rotated compared to the normal orientation. For typical northeast-moving supercells, if you put yourself in the path of the meso you'll at least get clipped by the forward flank, if not take a bit more direct hit from it, before it clears and the meso/updraft/tornado opens up in front of you. A lot of southeast moving supercells maintain the orientation of FFD to the north/east of the meso, which means they tend to "sink" south. This means if you put yourself in the path of the tornado, you can usually do so by staying entirely in the inflow region southeast of the meso without ever taking on anything close to FFD precip. Rarely have I seen a southeast-moving supercell with the FFD entirely on the east side of the updraft. Unless the surface winds veer to the southwest or west, the outflow from the FFD will cut off the inflow to the updraft in those situations, so the storms typically don't survive such an environment. That's actually the same reason left movers typically don't live long.