Do you cold core?

Scott Currens

I am curious about the % of chasers that chase cold core setups.

If you have chased cold core setups, how successful have they been? Where the tornadoes you observed landspouts or mesocyclone tornadoes?

I am sold on cold core chasing. The first three cold core chases of my career ended up being my top 3 chases of 2005. Observing tornadoes on March 21st, April 10th, and November 27th helped make up for getting stuck in the mud on May 12(causing me to miss the big show), and for leaving very late on June 9th & 12th.

Before 2005 I had several problems with cold core setups.

1) I thought cold core setups were a long shot. Now I am 3/3 and think the only time cold core setups fail is when know one chases them. OK, now I have jinxed myself.

2) I believed that most cold core tornadoes are landspouts. My experience so far is just the opposite. I have yet to see a landspout on a cold core setup. In fact I can't seem to find any photos of landspouts from cold core setups. I think the reason for the misconception about landspout vs. mesocycone tornado is based on the 88D's inability to adequately sample the low-topped miniature supercells that are common in cold core events.

3) My third problem was with the numbers. I couldn't look at a target area that is 57/53 with 200 CAPE and get excited. I now know that the CAPE values associated with a 500mb cold core low cannot be compared to what you see on the dryline. It is like comparing 1000 CAPE at 1000 feet to 1000 CAPE at 5000 feet.
I'm completely sold on cold core setups for all the reasons you mention. I became interested in them after April 11, 2001, as Jon Davies continued his research and the information about them became more prolific. Then I started watching him and Mike Umscheid pretty close for the decisions they were making on these days. What was happening back then was that the rest of us would make warm sector targets because the setup was more conventional, then we would come back to compare notes and see that these two were bagging tornadoes way up in the cold air. I had to know why that was (and still want to learn more) ...

I can see why Scott is psyched on them after November 27 ... but yes, I think they are very interesting chase days. The only drawback on these setups is that they typically occur in early spring/late fall on days with heavy duty upper dynamics, so they can be real bears to chase. But if you hug the low close enough, storm motion slows quite a bit.
I chase them if there's not another, better warm sector target the same day. However my CC chases have been absolute failure throughout my chase career. Either I ignore them or I simply screw them up. Here's a quick capsule review of my cold core misery:

May 16, 2003 - Ignored a backyard CC setup in favor of the warm sector in the jungles of SE OK/NE TX. Halfway to my target a friend calls to tell me of multiple tornadic storms just northeast of Oklahoma City, while all we were rewarded with all day was a single tornado warning near dusk in heavy hills and trees. The fact that it happened just ten miles from us didn't help ease the burn.

March 21, 2005 - Ignored the CC set up in favor of the warm sector in east centrak OK. Problem was, could never fully commit to one or the other in time, along with data stops that wasted time and gained us nothing but letting us know the place we'd just left from to get data was now under a tornado warning.

April 5, 2005 - Ignored the CC setup again for ther warm sector in NE TX, saw no tornadoes while the CC area had tornadoes.

April 10, 2005 - Wouldn't commit to the CC area until too late, and missed all the tornadoes by a county as we were 40 miles south and could never catch up to northbound storms.

April 11, 2005 - Dedicated myself to the CC area, firm. left OUN and drove straight to the upper low. Saw a crazy supercell but none of the storms that day produced tornadoes. A sup with no tornado is incomplete in my eyes.
I just can't drag myself to head away from the warm sector into an environment that's like 62/55 and 100 CAPE when I can go for the 70/62 w/ 1000 CAPE ahead of a dryline. I'm not sure why, and gosh knows that I was burned this year by refusing to head northward (from OUN), instead opting to chase marginal moisture in the "warm sector"... Got a small tornado near Paris TX in March, but not much else during those days when others were in KS and central/northern OK hitting cold-core convection. I guess I did get to see a supercell move over Norman, but that storm waited until after dark to finally produce.

I wish I could pull myself away from a 'warm sector is supreme' mentality. There were several days this spring that could be characterized as marginal CAPE (by warm-sector standards... i.e. 500-1000) but strong low-level shear (>500 m2/s2 0-3km SRH) in the warm sector, but obviously that wasn't enough... all the while, folks were hitting the goods farther north under the mid-level low. Maybe I'll give it a shot next year... Of course, then I'll miss a long-track, strong tornado associated with an isolated supercell that developed along the dryline and in an environment of strong low-level shear.. :roll:
What Jeff mentions here is likely the single biggest reason they remain largely unchased by the general chaser population. Now on a day like 11/27, no prob... the cold core target is close to home and I can just zip out I-70. But move that target further north over Nebraska and the second thoughts start creeping in ... mainly because on cold core days, the warm sector target is still a viable option - so it becomes a matter of weighing the two possibilities against each other. If the cold core is over Columbus and the dryline extends to Topeka/Salina - it's just so much easier to lay a wager on Topeka for me. But more and more I'm wanting to bank on getting up close to that low! The WHOLE trick with chasing these scenarios is to be able to RECOGNIZE the clues before the event. That is the supremely tricky part, I'm finding out. As time goes on, I'm slowly catching another clue here and there.

Here's what I would really like to see ... someone with more clout than me (a/k/a "everyone") ... please ask Dr. Josh Wurman to haul the DOWs north a time or two for some more cold core exploration. I would really be curious to find out about the low and mid-level dynamics that seem to be driving these things.
This is a good topic that I have much to learn about .

Just what are the parameters for a cold core set up for those of us trying to learn ? Thanks.

Jon Miller
The only day I chased the cold core target(that I can remember off the top of my head) was on March 21 of this year and the only reason I went for the CC target that day was because I was late getting out of town.
I read Davies paper last year, which made me more aware of the CC target on the closed low days, but it seemed like the CC target wouldn't have paid off much in 2004. 2005 was a different story. I had several days this year when I was torn between the CC target and the warm sector target, but I guess I'm kinda like Jeff and I'm always drawn to the warm sector (it's like a tractor beam).
The freshest CC setup in my memory is the 11/27 incident. I couldn't decide between heading North for the CC or heading East for the dryline/cold front. The deciding factor for me was that the mid level low was located SE of the surface low, which made me think that mid level winds would be too weak. I also remembered Davies saying that when the low was tilted to the SE it wasn't a good setup for tornadoes. I ended up getting the tornado in eastern Kansas that day, which helped to relieve the pain of missing the more prolific tornadic storms at the CC, but it still hurt. After botching that one, I am definitely more aware of the CC target and I would imagine I will chase it a lot more in 2006. I also need to read Davies new paper since I obviously still have a lot to learn about cold core setups.
April 7th 2004 is my date near Milan(Italy)...Here in Italy it seems that every cold core pattern that happens in one region of Italy, produces in the most of the cases at least a tornado. I start thinking that this is one of the most prolfic synoptic patterm for us.
This is a good topic that I have much to learn about .

Just what are the parameters for a cold core set up for those of us trying to learn ? Thanks.

Jon Miller

I too could use some instruction on 'cold core' setups.

Anyone got links, etc that would help me understand how to spot and chase these.

Thanks in advance from a newbie!

A Google search for cold core tornadoes brings up the two most common resources:

+ A preliminary climatology of tornado events with closed cold core 500 mb lows in the central and eastern United States... Jonathan M. Davies, Wichita, KS; and J. L. Guyer from 22nd SLS Conference -->

+ Jon Davies case studies... There are several on his page ( ) which you can find under the "Material about tornadic storms with 500mb cold core lows" (towards the bottom of the page).
Hey Scott - this year was my first experience with cold core systems. What happened to us on April 5, 2005 convinced Tony L. and I to leave the warm sector and hang back closer to the low center. That day we left Garden City, KS to chase the squall line east of Wichita and missed the numerous reported tornadoes back where we had started the day. On April 10th, 2005 we had our second chance to get it right and hung back near the low center and scored one of our best chases of 2005 in Trego County! I am sold on chasing cold core systems from now on! :)