4/10/07 NOW: OK

[Billy Griffin]

Very impressive, possibly tornadic cell (now Tor-warned) for Grady County in Oklahoma (southeast of Lawton).

[Billy Griffin]

Not sure if any chasers anticipated today, but this looks pretty bad for the town of Marlow, OK. Shear / TVS really impressive!
Appears to be cyclic, increasing intensity again just northeast of Marlow, OK.

Other cells don't look too bad throughout central Oklahoma. Some minimal shear on these as well.

Grady & Stevens Counties in Oklahoma... TORNADO WARNING

[Jarrod Cook]

Yeah this storm is a doozy. Very well defined hook echo and rotational couplet. Looks like it went right over Bray, OK at 7:05 PM local time. I don't see anybody near it per spotter network or APRS.

[Billy Griffin]

WOWZA !!! Most of these cells in central OK are taking on a cellular appearance and many are producing hail with some shear indicated. What in the world is going on? I think this one caught us all off guard, although OUN NWS did indeed have today outlooked for potential severe. I'll be darned.

Looks like the cell north of me (Norman) going through Moore right now is rather impressive, but nothing even close to that beast down south!

[Donald Giuliano]

Quite the nice little storm here, has had very impressive low-level rotation on several scans. I think Dan Dawson deserves some props on this one...was talking to him yesterday and he was interested in this afternoon as kind of an under-the-radar possibility. Didn't think anything would get going myself. Guess this is the year of the upper 50s dewpoints getting the job done. ;)

[Kenny Drake]

From eyewitness reports Im hearing on NEWS9 it does sound like the low Tds are having an impact. The Bray/Marlow/Doyle cell has a nice meso on it but no concentrated areas of rotation at the moment. Sounds a lot like the 4-1-06 cell south of Elk City last year that the entire chase community in Oklahoma was on. Had a nice meso, a funnel at one point, but no tornado. If this current cell can follow the warm front which extends SE from the cells present location it will have its chance. So far it seems to be sticking along the warm front, which is good for the cell anyways.

[Billy Griffin]

Yeah, kudos to those who decided to chase and who accurately forecast this one! We've had absolutely ZERO daytime heating (at least in the OKC area) and temps / TDs rediculously low. Is this some type of pseudo-cold-core thing with this warm front?

[Billy Griffin]

TWO supercells now! Pauls Valley, OK area and the southern monster, near Elmore City!

[cedwards]

The 12Z GFS picked up on this this morning. I wasn't too excited because it was still cold up here, but SW Oklahoma did heat up nicely. Tds in the mid to upper 50s in SC OK right now. Val Castor transmitted some nice pictures of the base when it was north of Marlow. At the time it was high based, but since the base did become more surface based.

[Bill Tabor]

Check out the Sig Tor Effective layer value and location:
http://www.spc.noaa.gov/exper/mesoanalysis/s3/index2.html

I was looking at going up north today, but the overall threat was too low to justify the drive. Some of you local Okies though ought to be able to catch this baby!

[Bob Schafer]

Actually, if you have a look at the mesoanalysis data, the parameters are pretty good for this. e.g., ADM last reported 63/59. LCL's are fine, there is CAPE, helicity, etc. etc. There has been insolation W of I-35 for quite some time... just not in OKC.

[Jason A.C. Brock]

LOL Nobody forecast this as of this EARLY A.M. not even SPC and the ones who are chasing it (if anyone is) hauled butt out the door when the Mesoscale was issued or the Watch. Which I kinda wish I had done myself then again we could drive ourselves crazy with such ideas. Lawton KSWO was reporting a sherrif saw a tornado near Bray but I doubt it....in fact about 10 minutes later a deputy reported that there had been no tornado. I am thinking the sherriff probbaly saw RFD type stuff. The base on these mesos havent dropped to anything below 7000 feet. I highly doubt any tornado was observed. I also wouldnt be surprised if the structure of the storm visaully is a little unphotogenic. Its high based and alot of dust is being brought in from the SW. If does have some nice structure tho I hope SOMEBODY got some pics. The tower cam from Duncan showed the storm with a rainfree base but nothing that would be considered jaw dropping.
Todays surprise scenario does bring up a point tho. Rapid moisture return does happen....and if this same scenario of rapid moisture return occurs Thursday....we could be in business.....and lets hope the storm system slows for Friday and we get supercells along I-35 at least and not in the trees. Hopefully multiple good cells spaced apart so we dont all kill each other getting there on the roads to. I will need to pack my lightbarglasses. :-p

[Mike Hollingshead]

http://www.underthemeso.com/index_2.php

Hopefully MikeU is getting some pretty pictures. I'm betting that tracking is a bit off a lot of the time thanks to less than ideal alltel data down there.

[Jeff Snyder]

The storm developed right along the intersection of a weak N-S dryline / warm front and the cold front that is sinking southward. The enhanced convergence along this intersection, along with the available instability, may have helped this storm survive long enough to develop strong vertical perturbation pressure gradients as the updraft ingested the helicity-rich surface- (or near-surface-) parcels. Of course, once these get established within a supercell, the ability to "survive" / persist in relatively weak CAPE is enhanced.

Check out the 00z soundings at http://www.spc.noaa.gov/exper/soundings/07041100_OBS/ .... Adjusting the sfc conditions for those southwest of OUN (e.g. low 70s over low 60s) likely yields somewhere near 1000 j/kg CAPE (similar to taking the FWD sounding and increasing the Td a bit while decreasing the temp a bit, possibly upping the theta-e a tad). At any rate, deep-layer shear on the 00z OUN sounding: 87 kts. 0-1km SRH: ~400 m2/s2.

[Dan Dawson]

Quite the nice little storm here, has had very impressive low-level rotation on several scans. I think Dan Dawson deserves some props on this one...was talking to him yesterday and he was interested in this afternoon as kind of an under-the-radar possibility. Didn't think anything would get going myself. Guess this is the year of the upper 50s dewpoints getting the job done. ;)

Thanks for the kudos Don, though I'm not sure how much I deserve it, given that I pretty much didn't pay attention to today's potential all day today, until this storm ;). That said, when I saw the storm developing, I almost went out the door to shoot down 35. I decided against it, given that it was moving at 50 mph and making a hard right turn :).

[Mike Umscheid]

Actually, I was indeed behind the storm the entire time... thanks to one costly tactical error earlier in the chase -- that said... the storm was a beauty from behind. The 45+ mph storm motion was too much with the zigging and zagging I had to do... 10 miles from the back of the storm, and still couldn't catch it. I called it a chase at Duncan. I was anticipating this day for a possible surprise catch since Sunday.

http://www.underthemeso.com/index_2.php

Hopefully MikeU is getting some pretty pictures. I'm betting that tracking is a bit off a lot of the time thanks to less than ideal alltel data down there.