2/10/09 FCST: TX/OK/AR/MO/KS

[Paul Austin]

Most of the issues stated earlier have now all but disappeared. The 850 winds are still slightly veered but, I don't think that will do anything but place a weak cap and keep the storms isolated until after dark. Almost all other dynamics are in place for a very good chase opportunity in February.

I was thinking the same thing in regards to the cap. A weak inversion becomes a good thing for discrete action with such strong kinematics. Tds to 60+ with a probable strengthening and slight backing of developing LLJ with time and a quickly clearing sky from the west under very strong westerlies spells a setup I wouldn't miss, even in that poor terrain, for a Feb setup. I'd be surprised if we don't see CAPE development near the DL/WF intersection and down into the warm sector on the order of 1500 J/kg (maybe as high as 2000?) with helicity and deep layer shear maximized near/just north of the Red River late this afternoon. Too bad I'm stuck here in Gainesville...FL. I've got to agree with Jim. It looks like we could have some long track burners through the jungles. Marc, those WRF sim refectivities are pretty scary. Depending on the sfc low track, I wouldn't rule out ne OK to se KS/sw MO perhaps a little later. Terry, ne AR could indeed become a decent target if the cloud cover clears some for enhanced destabilization. Otherwise, it might end up mostly being a late night show with sups embedded within a solid squall line.

Good luck to any who go out.

 

[Jeff Snyder]

There's not one target that jumps out to me when I look at the forecast data, as nearly all places from central OK southward into N TX look relatively favorable. From a logistics standpoint, I think a good strategy would be to either head closer to Denton, TX (I want to stay N of I20 for non-met reasons) or stay N of the Red River closer to Paul's Valley. I say this because, from chase experiences and Google maps "terrain" features, it looks like I'd want to avoid the area between, say, MLC and the Red River. Meanwhile, the N TX area E of I35 is pretty good until you get to Paris, TX (e.g. the triangular area bounded by I35, Hwy 56, and Hwy 24 is pretty good chase country); southeastern OK isn't bad as long as you stay northwest of Hwy 75. With a NE storm motion, then, I want to avoid having to cross into the area bounded by Hwy 75 to the west and the Red River to the south, which means I'll try to get closer to Denton (to chase south of this 'bad terrain' area) or stay closer to home nearer Paul's Valley (to play north of this 'bad terrain' area). AGain, that's entirely logistic in nature, and there's no reason why the best, meanest storm(s) will cooperate with such logistics.

Otherwise, not a big reason to rehash all the meteological points. I don't remember any past Feb chase days (N of I20, at least) that featured 60+ Tds, 50+ kt 850mb flow and 60+ 500mb flow. Looking at the sfc forecasts (winds, Tds, temps), I'm not really liking (a) how nearly perpendicular the flow is behind the front/dryline by 0z and (b) how quickly the front marches through the area by 6z. I think that lends further support to the squall line forecast along the dryline (and then front). Of course, 0z is immediately before sunset in the target area, so I'm not too concerned what happens come 3-4-5z. In addition, some of the FCST soundings 0z and 12z NAM forecast are slightly "S"-like in shape, particularly in the 'farther south' sub-target, which always frustrates me. I've never had good luck with S-shaped wind profiles, so I hope we can actually avoid these (you can thank more-backed-than-desired mid-level flow). Farther north, the forecast hodographs are considerably more straight (which would favor splitting supercells).

60F Tds already to the Red River E of I35, though the depth of the good moisture is a bit questionable. If we're going to see such strong 850mb flow (50+ kts by 0z per the 12z RUC forecast), I'd really like to see deeper moisture. However, it's Feb, so I can't complain too much. W Gulf coast soundings weren't terrible. Looks like the warm front at this time does lie just NW of HWY 75 (SE of OKC), as evidenced by temps, tds, and winds from OK mesonet.

 

[Matt Gingery]

Hey all, I will be in my White Ford F-150 with a metallic tool box and red vortex anemmometer on the roof, missouri tags. I am going to play the warm front early and hit the dryline later. I am going to head south on HWY 71 to Ft. Smith, and jump on I-40 there is a rest stop on I-40 25 miles into Oklahoma from the Ark. Line. They have Wi fi.Warm front action should get going early with a limited cap in place. I think playing the warm front and isolated cells along and south within the gravity wave will give a good play early, bad roads or not I'm chasing in Eastern Ok. Ill have road options towards McAlester and OKC. I will sit and loop visible satellite until I make a move

 

[Mikey Gribble]

I'm pretty much sticking with my same thoughts as before. I would target the area between Ardmore and Dallas (half way between the two). The Dallas sounding shows shallow moisture so I'm interested to see how the dewpoints will evolve through the day. You have good southeasterly surface winds bringing in better moisture, but the winds quickly veer above the surface layer. My other issue is veering 850mb winds. I can't remember hardly any good tornado days with veering 850mb winds. It just never works out (at least when I chase). 850mb winds do back some through the day if you go off the NAM, but again it seems like every time you are waiting on that to happen it either happens too late or doesn't happen at all. Those issues aside, the Paris forecast sounding does look pretty good for 00Z, especially since it's February. Good luck to anybody chasing today.

 

[Greg Blumberg]

Scott Peake, Andrew Ryan, Travis Darling and I (a few others too) are heading out around 1 PM today to Durant, OK last I heard. We'll be in a grey Yukon with weather equipment on top. I'm going to try to convince them to head a bit west due to the dryline being located a bit more west. I am pleased with the 15 knot winds we're getting to bring in the moisture after being slightly concerned about the moisture return . SPC Mesoanalysis is showing 750 m for the LCL and some interesting helicity values. I like what I see so far. Things could be better, but then again, they could be worse.

 

[Alex Lamers]

Right now I think SC Oklahoma is evolving just right for a few tornadoes later. The fog banks in the area will set up a few differential heating boundaries later this morning as heating continues in the wake of the mid-high level cloud cover clearing out. There appears to be one setting up from Southern Grady County into Southern Cleveland County.

In other news, dewpoints are almost 65F in Southeast Oklahoma right now. Is this really February 10th?? 60F dewpoints have advanced as far as Waurika to Ada (approximately) so far. In fact, looking at the 12Z NAM and GFS, the moisture return is way ahead of schedule.

12z DFW sounding showed pretty shallow moisture (to 900 mb at best). However SHV sounding showed much deeper moisture. This 850mb moisture plume is expected to advect right up against the dry line in the next few hours.

 

[Tim Marshall]

TARGET: GAINESVILLE, TX TIME OF DEPARTURE: AWAIT CI. This is a classic severe weather set-up on paper. So what could go wrong? CONS - I don't like the dense cirrus overcast over the threat area which will keep surface temperatures down. I realize there is significant clearing approaching from the west, with breaks in the overcast across central Oklahoma, but I don't think there will be enough time for surface heating to be significant. With all that upper forcing, I expect more linear or squall line mode to the storms. Expect to play the end of the line moving from MWL to Gainesville. Also, where are those roaring surface winds in response to the approach of the short wave? Need I say there are a few problems with today's scenario. PROS - However, I would agree that there will be a small window of daytime tornado opportunity within the first few hours after convection initiation. I do like the backed winds on the RUC along the Red River by 00z that will enhance the low-level shear. But, I will avoid chasing the night-time, fast moving squall line, with rain-wrapped tornadoes in NE TX and SE OK.

 

[Eddie Natenberg]

Sadly, I'm not in Oklahoma anymore, but I would like to pick a target. I would stay just west of the Ft. Smith AR area for a late show. I think that there will be squall line, but in all to many instances I have seen discrete cells form after dark. Therefore even though it wouldn't be the safest place to "realistically chase" the strong return flow through sunset there will yield a very saturated boundary layer ahead of strong upper level forcing with large low level hodographs. Just my 2 cents.

-Eddie

 

[Andrew Stoller]

The 15Z RUC shows the surface low further southeast into w central OK then yesterdays NAM/GFS runs, so winds are much more backed since the surface low is in closer proximity to the decent thermodynamics. Also, 925s are still backed and 850s are at least southerly - even backing in nc OK. Nice turning with height.

However, after looking at some model skew Ts on Earl's page, they don't quite backup the overall composite indices. Most of the hodographs look nice - much less veering in the low levels, but supecell potentials are in the 50s most spots in eastern OK, and SRHs are well below the 400 m2s2 level. Or maybe I'm just not seeing things correctly.

 

[Steven Vincent]

My target area for now is in-between Wichita Falls and Gainesville. I am concerned my laptop is not going to work properly today, and both my friends who are meteorologist will be tied up at their stations. My new data in the field is going to be limited, but I can't pass this up.

 

[Chad Cowan]

I'm leaving KC with a prelim target of Blackwell, OK. This area is right on the nose of the LLJ around initiation time which should be around 5 for the WF/TP. Hopefully we can get something before it gets dark but there will be tors late into the night.

Streaming live @ chasethestorms.com

 

[Paul Redmond]

Sadder still, I am tooooo far south in San Antonio to even consider leaving now. If I were up by Dallas or in OK, I would be all over this like a bad boy. A classic spring set up.


My only hope is that the squall line expands further south later this afternoon with some possible tail end charlie affects. Well hopefull the chase car will at least get a bath and the severe drought around here may be lessened.