Hopefully the veered 850mb winds will not be an issue the day of and we can get off some convection before dark.
Or any convection south of Emporia, KS, period! I'm becoming increasingly concerned about cap bust potential on Thursday, a risk that is being elevated by the fact that there's a considerably better chance the models are overdoing moisture return than there is the models are underdoing moisture return. A couple of days ago, it looked like 850mb Ts would stay in the 15-17C range across most of the area, but the latest NAM and GFS forecasts are pushing that ever-so-scary 20C 850mb isotherm a tad farther to the E. Accordingly, the last couple of NAM runs has kept the warm sector S of Emporia, KS, dry until after 00z, and the new 6z NAM has the warm sector S of EMP dry through the entire evening. Fortunately (for the southern target chasers, at least), it looks like the cold front is not going to move as far SE as previously forecast, which should keep things from going linear too soon. That said, I really, really would like to see the 850mb winds back even 10-20 degrees -- the idea of 850mb trajectories from W TX is not appetizing to me right now. We've seen the effects of veered 850mb flow several times this year, and it certainly isn't pretty.
FWIW, it also will help that there will be a strong LLJ in place across the southern and central Plains from tonight all the way through Thursday night, which will certainly help advect northward any moisture that is able to modify the cP air currently in the Gulf attm. I will be paying very close attn to Buoy 42002 (ESE of Brownsville, TX) and Buoy 42035 (SE of Galveston) over the next 18-24 hours -->
http://ndbc.noaa.gov/maps/WestGulf.shtml ... I better see mid-60F tds at those buoys by later this afternoon, or else there could be problems. FWIW, the current Td at 42002 is 58.6F, up from 51F about 21 hours ago. Water temp at that buoy is 77F, and the Td before the last cold front was in the 71-72F range. 00z NAM 12 hr forecast (valid 12 UTC today) is showing 65F isodrosotherm along or just southeast of the TX Gulf coast... Unfortunately, buoys in that area show that such a forecast appear highly unlikely to verify. For example, buoy 42020 (50 mi SE of CRP) just cracked the 60F Td mark, and I find it unlikely that Td will rise at least 5F in the next 3 hours. Then, the 00z NAM brings >65F tds into southeastern TX by 18z today... The 00z GFS looks a little more reasonable at 12z and 18z today, but it too ends up bring >65F into southern TX by 00z this evening. Buoy 42055 between mainland Mexico and the Yucatan peninsula is rebounding at a rate of ~0.75F per hour the past 4 hours (now up to 67.1F). The buoys are really all we have in the western Gulf, and they should be able to provide some insight into the moisture return off the coast of TX today.
The forecast 250mb charts show beautiful diffluence over the risk area as the upper-level jet streak fans out over the Plains, which I certainly like to see. This too made me question the previous forecasts of a farther east cold front, since there should be respectable pressure falls occurring over the western Plains as the jet streak noses out from the Rockies. My eyes are solidly focused on northeastern Oklahoma, where kinematics are nice and where moisture return should be slightly lesser of an issue (compared to locales farther to the N). One possible problem that's been in the model fcsts for the past few runs is relatively marginal deep-layer shear in eastern KS. Even farther south, some model runs aren't showing a whole lot of shear in the 3-7km depth, but the last few forecast soundings I looked at showed this to be more apparent in KS.
