Core Punching

[Mike Krzywonski]

At what point does core punching become dangerous? Is there a maximum hail size that is still considered relatively safe to drive through? What would be the radar indications for these scenarios? Other than seeking shelter, is there anything one can do to minimize risk if he gets caught in a dangerous hail core?

 

[Jason Boggs]

Core punching is very dangerous, not only because of the heavy rain and hail, but also because of a possible rain wrapped tornado. Imagine exiting out of the heavy rain and having a tornado bearing down on you with no escape route. Again, it is never a good idea to core punch and the only reason some people do it is because they were out of position to begin with. Here is a little graphic to illustrate why it's so dangerous.

http://img89.imageshack.us/img89/8718/coreje5.jpg

 

[Brian Emfinger]

I have to disagree a bit... When I was in middle school/high school and as few as 2-3 years ago while reading everything I could about storms and storm chasing...i really tried to stay away from core punching and when I would hear a report of someone doing it I would think they might be a little nuts and/or stupid. BUT these days with the proliferation of mobile internet and the data and radar that goes with it (especially GrLevel and GPS), I just don't think its got anywhere near the same level of risk as it used to. You can have a pretty good idea of where exactly that hail core is and where exactly the tornado is. Just watch on spotter network during a major outbreak and you'll see many outstanding chasers maneuvering all through a storm without getting into much trouble. Is there risk?...certainly but I personally am more concerned about hydroplaning than hail or tornadoes during core punching. Its just not the big deal it used to be...at least to me it isnt.

 

[Jason Boggs]

I will have to say that the level of experience the chaser has, does play a role. New chasers should avoid doing this at all costs. I will admit that I do it on occasion, but if it's rotating and it's an HP, forget it!

Another little opinion of mine...Don't ever depend on radar to tell you EXACTLY where a tornado is. There are just way too many variables involved.

 

[Bob Hartig]

Don't ever depend on radar to tell you EXACTLY where a tornado is. There are just way too many variables involved.

That was my conclusion from this past year. It takes roughly four minutes for level 3 to complete its sweeps in svr Wx mode, crunch the data, and transmit it to my GR3. Meanwhile, the storm continues to evolve--and a lot can happen in four minutes.

 

[Shane Adams]

Core-punching is one of those subjective topics. It's inherently dangerous from the outset, so rookies or newbies I would completely discourage. However, with a level of experience comes the possibility of successful core punches, and with much experience this possibility often becomes standard practice.

To start, it's obvious that if you've managed to position yourself favorably in relation to the storm, there is no need for a core punch. That's the easy part. Now, the reality is that even the most experienced chasers aren't always gonna get it exactly right on approach or forecast, so the inevitable need for a core punch will be in the cards.

The most dangerous part about core punching is not understanding storm structure; as I mentioned above, I completely discourage rookies and newbies from trying this. Even though the core punch is dangerous by nature, it can be done successfully with an understanding of storm structure and an old-fashioned sense of survival instinct; i.e., knowing when something's not right before you see it happening. When you know what you're up against, you've won half the battle, because knowing the structure also means you can judge the exact amount of danger posed by things like your distance from the updraft as you begin your approach, the direction of storm movement, the speed of storm movement, and the type of storm you're dealing with. When you have good experience in understanding and deciding upon all these factors, the level of danger from a core punch is cut in half.

Using the experience example above, there are still storms that even the saltiest of veterans will not punch, in particular a nasty HP with strong rotation. Then there are other situations where a chaser will choose to core punch, even though it may be dangerous in itself, because they have (and use) the experience necessary to pull it off. You can penetrate a core and come out into the clear directly in the path of a tornado, but when you're expecting it, it's not a shock or something that would cause panic. The chaser realizes the high-danger factor all throughout the core punch, and despite being in a tight situation (relative to the tornado), they can methodically move through the core, into the cage, and successfully observe a tornado from close range, without becoming debris.

One of the most dangerous aspects of core-punching (after lack of structural knowledge) is the panic that can be induced by not knowing or expecting what you might run into. Tight situations call for quick (and good) decision-making. Lack of knowledge schematically and lack of actual field experience can seriously hamper a chaser's ability to do this. So to wrap this up, read up on structure (the different types of supercells have different structures and personalities), go out and chase and get some experience around storms, and then after a few years or so, when you're brave or confident enough, then you can try a core punch. But bravado alone will get you in trouble; you need the seasoning.

It's tough sometimes to purposely back off when you're a rookie or new chaser, especially when you haven't seen much yet and you know the biggest prize of your career might be lurking in that core just a few miles away. I was faced with this decision twice during my first season and both times knew there was a confirmed large tornado on the ground inside the core. It was a bitter pill to swallow knowing what I was so close to but yet was still missing, but both times I didn't feel comfortable punching, so I backed off. The first time, the tornado dissipated about a mile southwest of me (I could never see it, found out through LSRs the next week). However the second time, on I-40 west of Lela, TX on June 11, 1997, we found a 3/4 mile-wide damage path less than two miles ahead of where we'd stopped.

 

[K Johnson]

I guess Im agreeing with everything already said... As a total novice I know there is not a hope in hell that I would purposefully corepunch.... on my own. I just wouldnt know when it was a reasonably safe option and when it wasnt. But... I have had the pleasure of core punching with experienced chasers/ drivers and I wouldnt have missed out on this for the world! I hope to repeat the experience in 2008.... But only with those with those more experienced leading the way.

 

[Mike Hollingshead]

I'm not sure there are a whole lot of indicators, other than *maybe* radar returns, on how bad hail might be. If you enter from the north or northwest, all you'll see is rain. And often there are storms with weaker radar returns containing some huge hail. June 7, 2005 in sw SD is one example I can think of. It was usually pretty small and not that intense on radar, and the updraft never looked that terribly impressive to me from the east. Yet it produced nearly 5 inch hail early on.

I also don't put much weight into ones ability to "forecast" and target ahead of time. Storms die and new ones form, all the time, last I checked. June 9th, 2003 O'Neill NE is one example. If you were near the first tornado, you'd find yourself out of position quickly on the one forming from the new updraft just southeast of it. Also road options. I seem to always find myself near a storm and having to make a decision to head further south then east, staying out of it, or a shorter route north into it, then east back into it(I almost always pick the shorter, core or not). It doesn't bother me too much during the day, but at night, yeah it bugs me. One example was May 4th 2007, in nc KS late. Punched north into it as it was crossing the n-s highway, in hopes to get north and get east again before it was up to that e-w highway. In hindsight that stuff is pretty stupid to me, considering at this very time the Greensburg storm to the south was doing what it was doing. For all I knew this storm could have had a tornado with it by the time I was punching back east trying to beat it. Add in darkness, hail, and horribly intense rain...well it tends to slow you down. Radar helps, but not when you lose your connection in the middle of all this.

And as for risk from dangerous hail. If you stay in a vehicle I think it will be very hard to find dangerous hail. If it is real concerning, just take a pillow.

 

[Gene Moore]

Core punching stories are best told over nachos and a couple of beers....they can go on forever. People talk about the blinding rain, flooding and large hail threat. These are driving dangers, but the real issue is coming out of a classic or HP core directly into the north side of the wall cloud/tornado. This is the type of storm where there is a solid rain wall just north, or up against the rotating wall cloud. In this case there is little time to react and storm features are usually obscured by darkness from the low clouds base. On days where the temperature dew point spread are close chances are high the inside of the core will be obscured by fog.

On the other hand there are some storms that look totally opaque then conditions open up once you're in there. I encountered such a supercell early last June NW of Midland. It looked rock solid, but once I got inside the edge of the core it opened up to about 2 miles visibility. I think visibility is the key here, if you can't see then best to let the storm pass and skirt the back rain wall to go south. Chasers tend to be pretty cocky until they actually get into a tornado, then they're never quite the same. Some chase tour groups punch cores routinely, no one dead yet, but in a long van I think it's not wise. My advice is get under the updraft early. That is, if you see an RFB updraft going for say 45 minutes before you try to get under it....chances are high you're going to get big hail. Also, wear tight glasses, safety goggles or safety glasses. At least have them on the dash where you can grab them fast. I have been cut up and one of my chase partners went to the emergency room with glass in his eye. Baseball hail will shatter the windshield with tremendous force. Tiny shards of glass will fly off the inside of the windshield and completely though the vehicle.

If you must, it's best to not punch the big beasts alone, a second set of eyes does help to watch the storm and the wind. It's never good when going through a storm to encounter very strong east winds. It could be your close to an imbedded circulation, or you're approaching the north side of the main mesocyclone. Remember, just because a mesocyclone occludes (wraps back) into the cold air and rain does not mean it will die out. Do not assume your storm has the classic supercell structure (Browning/Doswell model diagram). Mesocyclones can and do rotate around the SE, east then NE side of a supercell. This was happening with the Greensburg storm as it approached Great Bend.

Radar chasing is the rage, but a tornado can form in less than a minute and completed radar scans are 6+ minutes old. WX-Worx software tends to average out the inner core of a storm losing all detail of an imbedded meso. GRLevelX is much better, but not as dependable as a second person watching both the radar and the storm for you.

Common sense is the key. If you lose the windshield chances are you'll spend the next day getting a new one put in...if you're close to a big town. If not it could take days to find one. Not to mention the possible damage to your lights and other equipment on your vehicle.

Finally, there will be times when a cluster of very severe storms form and a chaser can get trapped with no choice but to drive through a supercell core, or sit it out. Especially at night it's human nature to head to a town to ride out a tornado warned supercell, but this can lead to a number of bad choices. It's better to pick the least dangerous side of the storm and ride it out than get into more danger trying to reach the comfort of other people....really a false security blanket.