10/17/07 FCST: TX / OK / KS

[Shane Adams]

I'm not seeing the tornado outbreak this morning. What I see is extremely fast, unidirectional windfields ala April 6, 2001. I'm confident there will be lots of severe weather today but as of this writing, I'm just not seeing a tornado outbreak. We can't even get the models to back the surface winds anywhere in the western 2/3 of OK as of now. Then again I've only glanced the RUC. Another thing I don't like is the instability and helicity remain out of phase on the most recent RUC runs, with the better helicity out ahead of the instability (what we have of it). Maybe I'm just not seeing this the right way?

Will wait for the next RUC update and see if I can clue into what others are seeing as a potentially huge day. We'll be out there regardless.

EDIT: We have decided on the area bound by OKC/PNC/TUL as an initial target. Shear is adequate but not ideal, but the main deciding factor for us is this area seems to have the best instability across OK, I'm guessing because it's closer to the LOW than more southern target areas and is benefiting from the colder h5 temps. This is by no means set in stone as parameters on days like today change by the minute and the final target will be an hour-hour decision until we're out the door.

 

[Mikey Gribble]

I have only briefly looked over things because I am in one hell of a hurry to get out of town, but I think SPC did a great job with the latest forecast. My opinion has not changed since last night. I think the Hobart to Chickasha area (off the NE tip of the dryline bulge) is going to be the place to be. Any storm firing along the dryline and tracking NE from there is going to be in the most favorable environment for tornadoes IMO. It is hard to tell now witout vis. satellite, but I think the outflow boundary from the storms currently tracking over central Oklahoma is going to be the money spot today. The are just South of this ongoing convection should have the best clearing and insolation. I think tornadoes are likely with a few possibly strong. I would think long-track is possible to given fast storm motions and strong wind fields. Good luck to everybody heading out.

 

[Dan Dawson]

Shane, I see what you are saying concerning the 12Z RUC. I'm going to go out on a limb and suggest that the model is smoking something in regards to the veered surface winds. It has them veered pretty much over all of western/central OK by this afternoon and evening, even well ahead of the dryline. Given the position of the surface low and mid-level trough axis, this doesn't make much sense to me. Indeed, the 12Z NAM now coming in still has winds mostly backed at least SSE ahead of the dryline all the way to 0Z.

 

[Shane Adams]

Michael's line of thought mirrors what we were thinking originally this morning. However, what soured us on the southern play was the lack of instability and helicity in the last few RUC runs. Helicity is basically impossible to exactly forecast and models should be taken with a grain, but the RUC has been stubborn about instability for a few runs in a row now. Our position works for either choice (I-44 to TUL or LAW) so we're just gonna keep monitoring things and changing our minds every ten minutes like we've been doing all morning.

 

[Brian Emfinger]

I am heading out as well today but I'm not optimistic. It just feels like a bust to me. I am heading off towards Henryetta for the same reasons Shane mentioned above just further south chasing clearing. I am sure we will get some strong storms today but I just don't see a great tornado risk with the lack of good instability. By most of our standards I bet today will be a bust...

 

[Karen Politte]

Agree with Shane that I think today is far from crystal clear as far as huge tornado potential. The concept of breakfast tornadoes never really did fill me with wonder.

CAPE values are continually kept low by the RUC in response to what I can only imagine is a constant cloud shield and debris from ongoing convection/precipitation. The large DL punch is fcst to take shape around Wichita Falls according to the latest crystal globe, and given that alone I'd probably intend to go and sit in Ardmore and see what happens with a view to very probably adjusting my target area east and north accordingly with new data.

Surface data currently shows significant sfc moisture from DFW-TXK-LIT at a stretch, and with our southeasterly sfc flow continuing it is believable that this could translate to srn MO by midday/afternoon in time for the "second coming" as advertised by SPC. If this can happen and if the upper trough can kick out along the four corners of OK/AR/KS/MO, then I would be watching and targeting eastern OK/western AR/southwestern MO for some significant severe weather later today into tonight IF we can clear out and realize some decent instability. Unfortunately, that's the one IF that I hate including in forecasts because it makes my whole post a no-cast.

Currently there is plenty of clear sky across western/northwestern AR, northeastern OK, southwestern MO and a bit of southeastern KS - which is my pick for a later target area. I know that the roads are great in southwestern MO, and given this I would likely keep a close eye on how things develop with a view to heading that way by the end of the day. I hope that I'm wrong and that the people who can chase see some daytime tornadoes in good terrain - because my forecast is the polar opposite of that LOL. Nighttime weed-wackers in NE OK/SW MO. Can't wait to see how wrong or otherwise I am by the end of the event.....

I'd intend to get to know the Turner, Muskogee and Will Rogers Turnpikes well today...

Good luck to all who go out,

KL

 

[Mikey Gribble]

I really, really, really don't trust the RUC. I'm not buying surface winds veering this afternoon. If it happens, it happens and there isn't anything we can do about it. I have to make the drive from ICT though, so I have to make the call now. All the models have been consistent with backed surface winds all the way up until the RUC this morning. Even the NAM this morning has them backed still. I don't see what would cause them to veer that badly with a deepening surface low. It's like it has them veering as the surface low migrates eastward at 22Z, but then they start to back again at 00Z. I think the RUC is out to lunch. I really don't have time to forecast now anyways, so I'm hoping for the best. Good luck to everybody heading out today.

 

[Shane Adams]

I'm finally seeing the light in this tunnel and am quite comfortable with our current plan of sitting tight in Norman and waiting for things to evolve. Clearing already beginning in extreme southwest OK. I think the RUC's paramters are fairly correct but the presentation/placement was out of whack...or maybe I was. Either way I am in total agreement with Michael and believe the I-44 corridor will be the magic spot sometime between 1-4pm. It was coded somewhat (to my eyes) but I've found what appears to be a fairly decent crack at a fairly significant event. I love Gribble's attitude: "If it happens it happens." I'm gonna bank on SC Oklahoma today, whatever happens.

EDIT: We're sitting in Bridge Creek, not Norman.

 

[Tim Marshall]

TARGET: ARDMORE, OK TIME OF DEPARTURE: NOON. Yesterday at this time I was hiking in Zion National Park, UT when I got a message that there was a MDT RSK for OK today. So, last night I flew back from Las Vegas, NV to chase. This morning, I don't like what I see. CONS: Lots of overcast skies this morning will keep surface temperatures/instabilities down. Convection already has fired across northern and western OK. Storms will race northeast. PROS: Strong dynamic system to romp across KS with plenty of lift. I like the dry punch aimed at the Red River later today, so I plan to stay south. Carson and I will head to Ardmore with the option of continuing farther north, south, or west as the day progresses. TM

 

[Brian Stertz]

I will be setting sail for either NC OK or SE KS in about a hour. The RUC has much of the shear pushing a bit eastward to this area by late afternoon/evening. Based on morning convection trends, this may be an area that regenerates and explodes later as the strong wave, dryline, and steep lapse rates interact. Plus this area is firmly in the LFQ of the mean jet streak that will be blasting in. Hopefully we can get the supercells up and tough before this plows in. May have some leaned over structures if they don't....which in turn stretches the tornadoes terribly and they cannot get grounded. I am just worried about playing too far west because these will need some time to organize and they will be trucking along at 40-45mph later.

 

[David Wolfson]

[VC] I would be targeting Lufkin, TX, by way of Waco, expecting to follow the tail of the trough/front ENE toward LA as it impacts the the old tropical circulation's backed flow off the Gulf. At least further south any storms won't be clipping along through the Ozarks at 30+ kts. FWIW.

 

[Chris C Sanner]

I agree with Shane and Michael on this one. Right now it looks like the area south of I-44 will remain relatively untouched by any severe convection and I suspect there will be some boundaries which will be lingering around in the I-44 corridor. Skies are relatively clear along the dryline right now and I would not doubt that is the case as it mixes eastward in at least a few spots. I'm watching and waiting in Norman and anticipating leaving for a Hobart-Lawton-Chickasha triangle for a target for today....

 

[Billy Griffin]

Highway 81 corridor between Chickasha and Duncan is my initial target, opting for leaving work around 2:30pm. I know we can second-guess the models to death, but I still will play the better instability today. All the shear in the world won't help this "crapvection" to be overcome. I hope for an isolated cell or two down there, perhaps tracking as far north as OKC metro by late evening.

Everyone be safe and happy chasing today!

 

[Jonathan Whitehead]

Im definately liking the area in SW OK per radar trends/clearing/mesonet obs/RUC helicity bullseye in the region, going to keep an eye on it.

 

[Ilya Neyman]

Regarding concerns about the RUC, and I only briefly cycled through it just now, it looks like the RUC doesn't bring the surface low as far south as the NAM and GFS, which seems to be at least part of the reason with the winds issue. Having said that, it still keeps a good southerly component at the surface.