3/9/2009 FCST: OK,TX,AR,KS,MO

[Brendon Lindsey]

Monday has been hilighted in the most recent SPC outlook. SE Oklahoma isnt chaseable but looks as if a storm or too could get going over in that area.

Cape gets up to 1000 j/Kg Over SE OK. Accompanied by 60-65 DPs. I havent looked to see how(I think the word is) deep the moisture is, but I think it will be better around 850mb than Saturday's setup is. Temps will be 70-75 deg. Not really seeing a cap. Would'nt mind having the GFS slow things down a bit and let moisture recover back up into central oklahoma/ NC OK a little closer to the surface low. There is a LI of -6 in SE OK.

I predict there will be a few naders monday, but I couldnt tell you how chaseable they will be.

 

[Connor McCrorey]

I'm interested. If the GFS slows down, things could get very fun around here. The moisture should be much better than this weekend, and that will be aided by water in the ground from rain on Saturday and Sunday.

 

[AndyGabrielson]

Looking at the new SPC area, TX is completely out of the equation. MO/KS are in for the win. Once again this one is working off alot of shear and "so-so" in many other departments. Although it does look like dew points might (key word) be a little higher in KS/MO than for the saturday/sunday event, but we shall see.

 

[Chris Lott]

Looking at the new SPC area, TX is completely out of the equation. MO/KS are in for the win. Once again this one is working off alot of shear and "so-so" in many other departments. Although it does look like dew points might (key word) be a little higher in KS/MO than for the saturday/sunday event, but we shall see.

I noticed this yesterday, and the runs seem to be consistent, but still time to flip flop. It looks like a nice dryline bulge into W.MO ahead of the surface low pushing through KS. Shear looks good, but again minimal CAPE appears to be the issue. It still doesn't look like a classic setup, but some potential still exists, and I think this will be confined to E. KS, W. MO, and NW. AR.

 

[Brendon Lindsey]

Well the NAM is painting a SC/C Oklahoma picture as of the latest run. Ha N.TX has 1500Cape. DP are pretty sufficient Around 60 . JW what makes the decision to put E/SE KS in the target area? I am just going off the few things I know. Any pointers would be tolerated haha. GFS definately showing a DL buldge in E KS. NAM shows one in C OK.

 

[Chris Nuttall]

MOD NOTE: If anyone is wondering why your posts may be missing, it's because I deleted/moved them to the correctly dated threads or changed the thread titles to match the event.

 

[Andrew Stoller]

The windfield and shear look great for Monday, but according to the 12Z Sat NAM, capping and low instability might be a serious issue, despite a rather sharp jump from low 50s dewpoints to the 60s in the span of 6 hours as forecast! hmmmmmmmm...

The NAM does break out precip across OK/southern KS by 00z Tue though.

 

[Brendon Lindsey]

WHERE IS THE INSTABILTY!?!?!? =( Everything is still looking as previously mentioned but there is no Cape....

 

[Shane Adams]

My concern for Monday remains the ridiculously-warm temps at 500mb, which is destroying the instability for this event. Shear is nice and with any luck, we'll be able to establish at least a small area of sun/warming. However these things tend to come out a little better than advertised, and with yesterday's crappy setup yielding some decent storms, I'm confident enough to take a chance on my target of Ardmore, OK.

 

[Shane Adams]

Lastest WRF presents a much better-looking target along the KS/OK border west of the Braman/Wellington area. Decent DL bulge and great shear are now being advertised, which IMO may be a better choice (over my 4-day old target of S OK) given the limited instability (thanks super-warm h5).

I've been zeroed in on Ardmore for several days now, but if the latest WRF becomes the trend through tomorrow morning, I may shift my target north to the Anthony KS/Alva OK area. I hate basing targets on shear alone, but with the lack of real instability that is likely going to play out, it seems there is no choice, for those seeking tornadoes.

 

[Scott Roberts]

I'll be holding off on a decision about whether to go out until morning. I like the WRF and the GFS, which are showing fairly good consistency in a target area within an hour or two. If the NAM plays out as it is on today's mid-day run, I'll probably hold off -- not interested in starting a week with a three-hour drive to the target. I'd like to see the surface winds backed a bit better, but we got action without it yesterday, and there is a decent amount of turn between 850 and 700.

My target at this point would be in a Wellington/Alva/Guthrie triangle.

 

[Bill Schintler]

Chase Target for Monday, March 9

Chase target:
20 miles east of Enid, OK.

Timing and storm mode:
Elevated storms will develop north of the OK/KS border by late morning. In the wake of these warm front storms, surface-based convection should fire along the dryline by 5 PM CDT. A few supercell storms along with a minimal tornado threat will be present.

Synopsis:
The WRN CONUS trough will amplify on Day-2 while phasing with the subtropical SRN stream jet as numerous small-scale impulses translate trough the strong SWLY flow. At the SFC, low pressure will remain anchored over SERN CO/SWRN KS; with a WF extending E along US-50 in KS. A DL will slowly mix EWD from the TX panhandle into WRN OK/KS late in the day.

Discussion:
Two primary concerns are the degree of moisture return as well as timing of lift on Day-2. Area 00Z soundings were dry with the exception of SHV, which indicated significant moisture in the lowest 200mb. H85 dewpoints AOA 10C were confined to locations S of a OSA/GDJ/SEP line in TX while return flow had been established ahead of the aforementioned trough. A 40kt LLJ from TX to KS will aid in NWD moisture transport overnight into Monday.

Daytime heating will be hindered by extensive CI, which will eventually push S and E of the area by late afternoon. Furthermore, broken SC will blanket areas in OK E of US-183. Elevated convection associated with the WF will be ongoing in the morning hours in KS, with this precipitation pushing NE by mid-afternoon. Timing of SFC-based initiation depends on subtle details of compact waves embedded in SWLY H5 flow. Lift will increase between 21Z and 00Z in the wake of the main impulse, with omegas of -6ub/s indicated. Convection should initiate just S of a DL/WF triple point by 23Z with the approach of an 70kt H5 streak.

LLVL directional shear will increase after 00Z as a SWLY LLJ strengthens to 50kts. Instability will be limited because of marginal mid-level lapse rates of 5.5-6C/km. This results in MLCAPE’s AOB 800J/kg and SFC-based LI’s of -2 at most. Nevertheless, STG flow in the mid and upper-levels will result in SFC-6km shear to 60 kts and SFC-3km SRH’s approaching 400m2/s2 along and N of the WF. LCL’s of around 1000m AGL will contribute towards a tornado threat. Storm motion will be towards the NE at 35 kts.

- bill


11:00 PM CDT, 03/08/09

 

[Jordan Hartley]

If we can get enough heating like we got on Saturday in Kansas I think tomorrow has the potential for a few weak tornadoes. Both the NAM and the GFS place a bullseye in a triangle from Alva to Enid and down to Watonga by 0z. Obviously with a lack of instability this will mostly be a welcomed rain event.

 

[Jeff Snyder]

Not a big day by any stretch, but I'm a bit interested in a NC/NW OK target. The 00z NAM continues to indicate some decent 0-3km CAPE and strong 0-1km SRH in northern OK W of I35. As we know, better CAPE will reside farther south, and the warm (-10 to -12 C) 500mb temps will be the likely limiting factor in this setup. Well, I suppose -10 to -12 is just fine later in the year when we have 65-70+ Tds, but it's tough to do with 70 temps and 58-63F Tds. Regardless, decent low-level CAPE may help tilt and stretch the vorticity provided by very strong low-level shear. I'm actually looking into the Fairview area for mid-later afternoon supercell potential. I don't have much luck/success in these very low CAPE situations, but the combo of relatively low LCLs, strong low-level and deep-layer shear, and a warm front around gets my attention a bit.

 

[Andrew Revering]

I'm actually most interested in the far southern target... I'd go as far as San Angelo, TX.

Hoping that the cap can break, everything comes together here for me. The problems I do see is that the boundary/low is not going to move an inch until after dark, so forcing is going to be an issue, but as soon as that strong low starts to move, forcing will be abrupt.

I think north of this area I fear the shear is actually *too strong* given the amount of instability. Not a lot of hope or certainly confidence in my forecast, but if I had infinite ability to chase, I'd be in Texas.