Thursday, February 14, 2008

Severe Storms Saturday?

The large upper level storm system set to hit part of Texas has slowed considerably on the models lately. Just looking at the 12z NAM today (14th), the closed 500mb low will be centered somewhere near Midland/Odessa at OOZ Sunday (Sat. Evening) with sw flow of 55-65kts spreading over central and southern TX. Above that, a 200mb jet streak will be rounding the base of the trough with winds of ~120kts from the WSW. At the low levels, a front will have pushed into the area sometime Friday and likely stall out near the coast. With the approach of the earlier menitoned trough, strong low-level warm advection should take place Fri night/Sat morning lifting the stationary front north some allowing richer gulf moisture to filter into southern TX. Sfc winds are forecasted to be from an SE direction at ~10kts. 850mb winds are likely to exceed 50kts from a southerly direction. With this said, the speed shear and directional shear profiles are supportive of supercells over much of southern TX. With 850mb winds quickly veering behind a cold front from the west coupled with strong forcing, a squall line will likely develop overnight but there may be a period with isolated supercells on the tounge of the low-level jet before that. Instability depends mainly on how far north the retreating front can make it but 500-1000j/kg CAPE values may be likely from I-1o south to the coast. With all this being said, I'm watching this closely for my first chase of 2008. It falls on a weekend so I might have to jump on it. Check back later for more details.

Extreme Early Target:
Yoakum, TX

Sounding for Victoria, TX 00z Sunday 17

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