6/8/07 FCST: TX / OK / MO / AR / ?

[Jeff Snyder]

Range is getting a little long, but we're within the 7-day max for FCST posts, so I figured I'd start a FCST thread for Friday.

Gulf moisture will remain entrenched over the southern US, with the Gulf finally open for business for an extended period of time. This thread will focus on the southern Plains, but a new thread may be necessary for locales farther to the east (Carolinas, etc) given the large areal extent of severe weather threat.

The GFS indicates that the deep moisture will remain south of the best flow aloft, but the souther fringe of the strong 500-250mb flow may yield sufficiently-strong deep-layer shear to support supercells in a strongly unstable airmass across Texas, Oklahoma, and adjacent portions of southern Missouri and Arkansas. Surface winds are forecast to be rather veered across the central MS River valley, but may be more backed to the SSE or SE across OK and TX ahead of a surface low forecast to reside across southwestern TX Friday.

At least we'll be back to chasing in 92/73F conditions! Hope everyone's A/C is working!

 

[SteveCarter]

This set-up has my attention too, but think I would add sIllinois to this. and maybe even eKansas. Hard to get TO excited about this with Wednesday's HUGE possibilities lying between now and this one, but dynamics do seems to be there for Friday, and Saturday both. Looks, IMHO, that this system may virtually crawl to a near standstill in this area, after Thursday, so I think I may go for this one....still early.

 

[Bill Schintler]

Chase target:
Imperial, TX (20 miles NNE of Fort Stockton)

Timing.
Storms will fire along a stalled-out cold front at 1 PM CDT. Storm mode will primarily be multicell, however a few short-lived embedded supercells will be possible. Storm intensity will generally remain below severe limits. During the evening hours, storms will evolve into an MCS, and Odessa may be a good overnight destination for a nighttime lightning show.


Synopsis:
Unseasonably strong system with impressive synoptic-scale forcing has brought a wide variety of severe WX to much of the CNTRL CONUS today. 00Z analysis indicated 100kt H5 SWRLY flow along E side of high-amplitude trough which continues to show a positive tilt. The highest H85 dewpoints have been pushed E of I-35 from TX through IA. A 981 mb low was centered N of Lake Superior while a synoptic CF extended SSW across CNTRL IA, SERN KS, and CNTRL OK. Convection has fired well E of this feature along a pre-frontal trough.

Discussion:
Tomorrows WX maker should be returning upslope flow in SWRN TX along a stationary CF as SFC high-pressure moves rapidly to the E, while reaching ERN KS by 00Z. A 20kt SRLY H75 LLJ over ERLY SFC flow will result in significant hodograph curvatures throughout the lower 2km despite weak ULVL flow. SRH (SFC-2km AGL) will be 200m2/s2 however deep-layer shear will remain AOB 25 kts. Storm initiation will be early as convective temperatures of near 90F are reached by early afternoon. During the evening hours, a 30kt SERLY LLJ should aid in the maintenance of a nocturnal MCS.

- bill



[FONT=&quot]10:30 PM CDT, 06/07/07[/FONT]