2014-10-12 FCST: OK/TX

James Gustina

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Looking like a particularly tricky setup has started taking shape on the GFS over the last few runs. The most recent 12Z run placed a surprisingly moist airmass ahead of a sharp dryline/1000 mb sfc cyclone in SW/W Oklahoma across the Red River into Texas. A pretty high-amplitude trough with an embedded impulse swings out of the Rockies Sunday morning and begins to nudge into the region after 18Z. The GFS is progging pretty substantial deep-layer shear at or above 45 knots with decent turning (I think a critical angle of 84 at FDR) and a pretty large inflow layer with >400 m^2/s^2 0-3 km SRH across SW OK by 00Z. The thermo profile looks surprisingly good for October with MLCAPE reaching over 1750 j/kg by 21Z in SW OK and pretty decent lapse rates just on the nose of the dryline with backing sfc winds throughout the day.
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Now with that said, very very high H85 temps over 20C are progged to overspread the dryline throughout the day and a Swly LLJ may promote more dry air being drawn in from SW TX and gradually mixing out BL moisture to lower than what the GFS has (which is likely given that 65F dews seem unlikely in the immediate wake of a cold front). The 12Z NAM also disagrees heavily with the magnitude of mid-level winds and has rather linear forcing and meh moisture return the day of which would likely lead to some pretty crap, anemic conditions. It also doesn't have cyclogenesis taking place that morning leaving a rather broad area of low pressure over the TX PH all day with a pretty diffuse "dryline" feature.

Just something to watch. This next cold front coming through tonight/tomorrow will really determine if we get the moisture we need or if this just disappears completely.
 
Not bad looking, but your DCAPE is pretty high, and along with some mixing out aloft makes me believe that outflows will probably be dominant and excessive RFD's will be the main fixture. Combine that with a squirly s-shaped hodograph, and it gets even more unlikely for tors. If you can get lucky you might be able to get a tail-end charley that isn't ruined by the flurry of outflows. Best of luck, you guys will probably take anything you can get after being so slow this year!
 
I'm not exactly sure the DCAPE logic is right here. That's actually relatively little DCAPE for a severe weather/tornadic sounding... the Omaha sounding that was launched just before the Pilger, NE Twin Wedges had over 1700 J/kg DCAPE. However, I do think that dry air entrainment and mixing are issues to consider for the day. As far as the actual setup goes, 00Z GFS doesn't look OMG, but it's still something worth keeping an eye on given the time of year.

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Personally, I like what I'm seeing. Mainly because this will likely be one of those "mesoscale accidents" type of days. Yesterday was one of those days with that HP tornadic cell in the panhandle using limited moisture and the storm near the cold front. The shear and moisture look as good as yesterday. The 850s are a touch stronger. The instability looks weak but there could be some pockets of stronger CAPE the NAM isn't picking up. With the proximity of home, I'll probably poke my head out there. Could be a chance at some nice supercells and gorilla hail.
 
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