10/20/09 FCST: TX/OK/KS

[David Wolfson]

Latest models show more vigorous shortwave energy rapidly entering the CA coast than previous runs. They are starting to account for some surge from Rick south of Baja up into the southwestern high Plains. I would not be surprised if the surge ends up even a little stronger than shown.

Timing is iffy for storms to break out before dark, but the params look to me possible for supercells and a tornado or two. Perryton, TX, would be my starting point.

 

[Bart_Comstock]

I just don't see much of anything happening on this day simply due to the fact that this system is moving into the plains to quickly to allow sufficient moisture return. The gulf will still be in recovery mode tomorrow, and there just wont be enough moisture to transport north despite the fact that southerly flow has returned to the southern plains.

 

[Brandon Goforth]

I just don't see much of anything happening on this day simply due to the fact that this system is moving into the plains to quickly to allow sufficient moisture return. The gulf will still be in recovery mode tomorrow, and there just wont be enough moisture to transport north despite the fact that southerly flow has returned to the southern plains.

Yep, I agree completely. I just took a brief glance at it and 2 things stick out to be the obvious killer...low moisture and strong cap. Granted you often can get away with lower moisture over the higher terrain, but quality moisture return just isn't going to happen this time around. And that cap is forged steel. I don't see anything going down either.

 

[Lanny Dean]

David,
latest runs do not look that impressive to me IMO. WRF still only painting mid 50 dews from 18z through 0z. With little to no turning from 1000-700mb. Also, it looks as though the 850 "jet" if thats what you want to call it, is placed well east of the instability axis. Likewise, simulated 700 winds remain below 30kts, not to mention 850-700 temps.
With little to no turning, no real punch at 700, strongest 850 winds well east of that area and less than 55 degree dewpoints....I just do not see any tornadoes much less any "real" supercells.

 

[Angie Norris]

Agreeing with the guys here. Shear is minimal at best along with minimal moisture and the most impressive cap I've seen in a while. I'd be surprised to see even a rain shower form tomorrow.

 

[David Wolfson]

Strong hurricanes are Theta-e machines. The extent to which this thermodynamic energy advects northward affecting synoptic scale mid-latitude baroclincs is often greater than expected. One sees this over a deep section as a tongue or "surge" emanating from the northeast quadrant area of the tropical system, through far west TX and north-northeast. In turn this intensifies the shortwave dynamics resulting in a distinct 200h max in northeast NM at 00Z, per the 18Z NAM with its left-front quadrant over the extreme north TX Panhandle promoting divergence in the 250-500h flow.

As others note the marginal wildcard is Gulf moisture return, which shows to be a little less than last night. Despite this there is a favorable axis in the north TX Panhandle area where there is >1" PW, 0-3km EHI >1.5, minimal CINH, and possibly the forementioned strong-enough upper impulse to initiate convection. The NAM does break out some convective precip. in the 00-03Z period. There's (still) an area around Perryton, TX, with reasonable LCLs and LI for a surface-based storm. The SPC is now recognizing many of these factors and may upgrade to a categorical risk depending on surface moisture per the current Day 2 outlook.

Obviously a marginal call , but a possible gift for those in the right area if something can get going before dark. FWIW.