5/10/08 FCST: TX / OK / KS / AR / MO

[Shane Adams]

I'd share Jeff's enthusiasm based on every parameter except I'm not at all digging the h85-surface winds. LL veering seems non-existent, but with the amount of instability perhaps that can be overcome. Regardless we're heading out and basically driving east on I-40 to get out ahead of where we think things will go...will adjust back west or south or whatever as storms develop.

 

[mark plate]

Low level veering is actually quite good at 21Z, but rapidly deteriorates by 00Z in ERN OK into WRN AR. Should be an early show in the Tulsa county warning area with best tornado potential in the 20-23Z time frame before the threat shifts rapidly east.

 

[Tim Marshall]

TARGET: Paris, TX TIME OF DEPARTURE: NOON. Agree with Jeff P. that the I-40 corridor looks best. My target town would be Fort Smith, AR. However, I don't like chasing in the hills and trees of E OK or W AR, so I'll stay south and play any tail end charlies that come my way. PROS- Strong dynamic system will provide plenty of lift. Wowza CAPE with 70 plus dewpoints in northeast Texas. A dryline will mix eastward rapidly passing DFW-OKC this afternoon. NEGS - Convection is already firing as of 10 AM with cells in S OK and S AR with T box already issued. Veering winds progged on RUC over NE TX and S AR by 00z, makes me want to trek north to I-40. AR does look like it is trouble -again. TM

 

[Mike Peregrine]

I would be much more inclined to head south if this were just slightly further north. In looking at RUC, I'm thinking EMP would be a long shot at this point. It shifts instability and surface low east quickly between 18z-0z. I'm tempted to head for Joplin, but even there you're on the edge of the Ozark plateau and will move into the trees very quickly along with the storms. Surface dewpoints are fine today, which had been a question last night, as I noticed SPC was concerned with deeper, quality moisture. I think we have the possibility of another Arkansas tornado outbreak today. Just can't bring myself to head down there yet. If there is any possibility of a stronger northern push, I'm out the door.

 

[Karen Politte]

Well we're one of the few who are obviously going all-out for the central-eastern AR play today. Mobile currently - main plan is to station ourselves just north of LZK and monitor.

Our FCST for today is to play the warm front as it surges northwards later this afternoon. Having no interest in hacking our way out to Mena, AR, we will focus on whether the warm front make it as far north as the models are progging. Today will depend mostly on getting storms in chaseable terrain, hopefully east of LZK somewhere. Agree on big potential for a tornado outbreak should things come together. Current convection in southern and western AR has died or is dying, so hopefully this will not lead to any sort of southerly reinforcement of the warm front.

RUC is consistent in bring the warm front north to MEM by 21Z and by 0Z shows very agreeable air mass in place across most of eastern AR.

Sitting in Crystal Hill currently with data, monitoring.

KP

 

[Bill Schintler]

Chase Target for Saturday, May 10, 2008

Target:
McAlester, OK

Timing and storm mode:
Surface-based supercell storms should fire by 5 PM CDT. A full-spectrum of severe weather is likely, including a few tornadoes. Unfortunately, a poor road network along with extensive trees and hills exists south of US-40 and east of the Indian Nation turnpike in OK.

Synopsis:
A S/WV trough will overspread OK this afternoon while the LLJ noses into NERN OK. The 12Z sounding out of OUN already indicates nearly 4000J/kg of MUCAPE while moisture was pooling at the nose of a LLJ over SWRN OK. Upstream soundings also indicate an EML over a well mixed moist layer 100-150mb deep. Morning hodographs are impressive, exhibiting large curvatures from the SFC though 10kft. Somewhat of an interesting SFC map today, with a CF analyzed along a PNC, END, to just N of LBB line. A WF extended from SWO to MLC in OK. A diffuse DL was organizing in WRN OK S into TX, and elevated convection has fired just S of TUL in a zone of WAA and isentropic lift.

Discussion:
Elevated convection and overcast will move to the E, allowing for the BL to destabilize. Low pressure will move rapidly to the E today, tracking first along the OK/KS border and then NE into ERN KS by late afternoon. This will in turn push a CF through much of OK by 00Z. Winds will remain backed NE of a WF, CF, and DL “quadruple pointâ€￾ west of MKO by 23Z, while a DL sharpens S along the I-35 corridor. SFC-based convection should fire towards the N end of the DL close to where it intersects the WF. SFC dewpoints will rise into the low-70s while CAPEs rise to as high 5000J/kg beneath nearly dry-adiabatic mid-level lapse rates.

- bill
11:30 AM CDT, 05/10/08

 

[Ben Prusia]

Looking at both the RUC and the NAM models, there is some potential for some supercells as far north as the Kansas City metropolitan area. Both models take the surface low into west central/northwestern Missouri by 0Z Sunday. The models also indicate S-erly to SSW-erly H85 winds in the more northern target compared to further south where they are more SW/WSW-erly. Surface OBs already reveal moisture surging northward with dewpoints already reaching the upper 50s in Parsons and Coffeyville at 11AM. If we can get the cloud cover to break up, which appears likely by the latest visible satellite loop, I would definitely not discount SE Kansas, NE Oklahoma into W Missouri for potential for some supercells, per the recent move of the SPC to include the Kansas City area and points southward in a 5% tornado potential on the latest D1 outlook.

But I agree with most anybody else that the main show will be in Arkansas, where higher instability is located.

 

[Mike Peregrine]

Well - a CF chase is better than no chase at all, I suppose. We'll see how it goes, but yes - was also encouraged by the northern possibility opening up at this point. Butler to Neosho is actually fairly chaseable terrain. Though it doesn't have the monster CAPE, 1500 j/kg would be fine if the winds back and the moisture is there. Think I'll take a chance after all - storm motions in this area generally look E-NE at 30+kts. That just might be do-able for us northerners.

 

[Mike Smith]

Sitting at the Wendy's at Beto Jct., Kansas (U.S. 75 and I-35). I'd like to direct your attention to the convective model:

Valid 4pm: www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/hiresw/12/images/hiresw_ref_009l.gif

Valid 7pm: www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/hiresw/12/images/hiresw_ref_012l.gif

I believe the area from Beto Jct. south southeast to CFV is a likely area for initiation and, perhaps, rapid supercell development. 18Z helicities, centered over the Flint Hills are over 200 (0-1km) in many areas.

Good luck and be safe this afternoon.

 

[Jason Persoff]

Were that I were to be out there right now. SC/SE OK along the TX border (and east to AR) has become uninhibited w/ zero CIN, CAPE has exploded beyond 5000, potent SE (and almost E) winds blowing along the OK/TX border. SRH >250 in this region. Satellite shows cirrus is dissipating rapidly with trailing early Cu field in its wake. It's hard not to drool over the keyboard. The worst thing is that it's over tough terrain for chasers (though Jeff P has always had excellent luck down there). I note that no cells are thus far forecast to occur per WRF in the SE OK region, but I'd be there awaiting the nose of the dry punch this afternoon. High CAPE, decent shear...Move the whole show 500 miles west into the Caprock, and I think you'd have heaven.