3/20/06 REPORTS: Oklahoma

Tornado near Putnam, OK on my Birthday!

Incredible 'cold-core' setup over Oklahoma today!

Intense vorticity advection + minus 25 Celcius 500mb temps + occluded pseudo warmfront + mid-40 dewpoints = 'nice low-topped tornadic supercells'

I targeted Hammon, OK and ended up 30+ miles to the northeast near Putnam where I caught an awesome low-topped supercell, which dropped a nice cone tornado.......and the dewpoints were in the mid 40's!!!!!!!!

On top of all that it is my Birthday today!!!!! I don't know if anything beats a Birthday tornado, no matter how it looks!
I chased a short chase today. I wasn't watching the radar or the weather real close today as I had my arms deep in a computer. :angry: I finally surfaced to answer a phone when a friend asked "are you going out on that storm down by Enid?" "Storm? What storm" says I. Fired up the NOAA page and sure enough, Theres a really wound up storm near Marshall.

I took of south on US 77 hoping the storm would hold together long enough for me to intercept it near Perry. Nothing but drizzle and grunge until I get to Perry, my visibility severely limited, I hang out in Perry for a few minutes trying to decipher the TOR Warning. Two storms, one near Stillwater, but no reports on it and the one near Marshall which was still TOR warned. I decided to move down I-35 to the Orlando Exit and run into a couple of Spotters who informed me that they had been called off and it was supper time. Ok. I'm deprived. I go off to OK 51 and head west so see.... Nothing. The storm had fallen apart quite quickly and I saw some low scud moving around, but nothing to indicate that there was anything more left. I did see one lightning bolt. Nice claer sky south of OK 51, and on the way home fell back into the drizzle.
Robin Tanamachi and I headed out this afternoon from Norman. We weren't expecting all that much, but were enticed nevertheless by the great visibilities and the possibility of low-topped supercells. We were in contact with Gabe Garfield, Jeff Snyder, and Justin Walker, and they did a great job of vectoring us toward a developing supercell in Dewey County. As I was talking on the phone with Gabe, the tornado formed while we were still near Geary, getting ready to get onto 270 to head NW. I thought to myself, the visibilities are so good, we might actually be able to see the tornado from here, and so at the nearest opportunity we pulled off to get a view to the NW, and sure enough there it was, a small but very distinct white cone on the horizon! We calculated that we must have been at least 30 miles from the tornado when we first sighted it! We continued on 270 to try to get closer to it as quickly as we could.

By the time we turned west out of Watonga, the tornado had lifted and was occluding, but we could still see the funnel aloft very clearly. We snapped a few photos and recorded some brief video. We continued toward the storm, hoping for a new cycle, but the storm quickly became outflow dominant, so we headed back east toward Watonga to try to catch some new convection that had formed over our heads while we were busy with the old storm. (By the way, we noticed some spongy half-melted hail/graupel splatting our windshield from this developing storm. It almost looked like nearly-melted snow!). On the way back east we admired a beautiful double rainbow as the sun began to set. We took a brief jaunt north off of 3 to Alpha to take a look at an interesting lowering to the north, but quickly realized it was a shelf cloud (which had some vigorous rotor circulations on it's leading edge), so we called off the chase and headed to Buffalo Wild Wings to celebrate our first tornado of the year!

Thanks again to Gabe and Jeff for giving us ground-truth updates via phone and Ham!
I, Gabe Garfield, and Justin Walker headed out today and found success. Originally, we though of heading into SW OK, but changed that plan after seeing surface winds veer to the SW, which (a) reduced low-level shear and (B) would certainly help mix out the meager moisture that was there. Seeing rapid clearing occur across western OK, and noting a pseudo-warm front that stretched across northwestern and northcentral OK, we headed west on I40.

We stopped for some food and gas in Weatherford, where we noticed TCu building to our west. After looking at mesonet data, we reaffirmed our idea to play the boundary to our northwest, where there lay a nice boundary that baked under some good insolation. Justin had threatnet open, which showed that the strongest storm was in northern Custer and southwestern Dewey counties. Since this storm was approaching the front, we opted to set up show east of Taloga (in eastern Dewey County) and watch the storm approach (which was easily since precip wasn't too heavy and the storm was only moving ~30mph). We watched as a nice wallcloud slowly developed, followed by a classic RFD punch and occlussion. When this occurred, the northwestern part of the wallcloud (it looked like the RFD cut the wallcoud in half) developed a nice funnel, which slowly descended. Right before 5pm (I think), the tornado snaked it's way to the ground, and remained there for a minute or less. The funnel aloft continued to spin for, I think, about 10 minutes after that, while rotation increased to its east and a new wallcloud developed. This whole thing was awesome, since (a) we were somehow avoiding significant precip (thereby giving us a nice view of the rotation to the SW) and (B) giving us plenty of time to tripod.

As the storm moved eastward, we headed south, encountering some very odd "snowballs" that fall along the updraft/downdraft interface. I certainly wouldn't call it hail, since it looked more like, literally, snowballs falling from the sky. I assume it was graupel that was able to make it to the ground given the relatively weak updraft velocities (which they looked like) and the very cold temperatures. Oh yeah, I should mention, I was in my heavy winter jacket while filming this storm, as temps seemed to be in the upper-40s and it was quite windy.

We followed this storm to the east, where it eventually became a convective mess. We called off the chase east of Watonga, after which time we headed back to OKC to make a TV video drop. We figured this would be as good a chance to get the vid on TV as any, since it was a low (or no) hype day and we saw no other spotters/chasers out in the field.

Overall, this was a very rewarding chase. I love finding success on low-hype days, especially since this was my first cold-core 500mb low chase. The snowballs that fell on us as we drive near the updraft base were also very odd to experience. In addition, I never imagined I'd be filming a tornado while wearing a heavy jacket and wishing I had gloves. LOL. Finally, it's great scoring on a day with little previous talk (e.g. 0% tornado risk on the 20z Day 1)... I'm a little curious as to why they dropped the tornado prob on the 20z outlook, since a look through the Davies and Guyer paper revealed that the setup across nw OK looked favorable for cold-core tornadic mini-supercells. Granted, the area to the sw looked horrible, with sw or WSW winds and 35-42F dewpoints. However, right up along that front/boundary (with Tds in the 47-50F range), things looked quite good to us. The dewpoints were a little low for many of the cases they looked at, but the mid-level temps were also on the cold side for their dataset. After looking at the SPC/RUC mesoanalysis graphics again (I can only loop to 0z now), this is a good reminder that you should only use these graphics for guidance! I'm not a fan of the thermodynamic fields of the mesoanalysis (CAPE and CIN mainly), since I've chased enough (and compared with enough soundings) to realize that they should be taken with a grain of salt. The kinematic fields usually seem to match up pretty well with observations (e.g. soundings), but the thermodynamic fields don't always fare very well (in my experience, it seems to overanalyze CAPE -- sometimes by 2- or 3-fold -- and underanalyze CINH; of course, in this case, I think it did the opposite).
Well Jeff pretty much summed up our chase summary nicely, definitely a nice grab considering the situation. Looked like a classic coldcore setup!

Here are a couple of video grabs:



Here is the other part of the wall cloud that started rotating, actually you can see both funnels.