Tornado Central

There continues to be some potential for Wednesday, but the setup faces similar obstacles as the previous one (namely, questionable moisture and initiation). Last night's NAM was forecasting southwesterly 850mb across most of the southern plains, which was ushering in very warm and dry air just above the surface. Through the past few model runs, however, the NAM appears to have backed off this forecast, with the more recent 00z run backing the 850mb flow to SSW by Wednesday evening. There appears to be an opportunity for a rogue supercell in a relatively narrow zone of reduced CINH in northcentral Oklahoma (+/- 50-75 miles), as upper-50s Tds (and maybe even >60F) combine with 65-75F temperatures ahead of the dryline to produce ~1500 j/kg SBCAPE. Questions of initiation remain, as there remains some capping which may suppress convection until after dark. There is a hint of a lobe of mid-level vorticity swinging through the area near 00z, but the "big kahuna" hangs back until ~12z the following morning, so we won't have much DPVA to help out. It'll be a tough call, but that's relatively common for this time of year.

The NAM forecast sounding valid 00z/01 at OKC looks rather tempting: http://beta.wxcaster.com/cgi-bin/par...TION ID=_KOKC

It's important to note that the GFS is considerably less aggressive with moisture return, indicate pitiful moisture depth (and magnitude). If this verifies, I'll look back at this post and shake my head, for it'll feel silly to even consider chasing given the look of the GFS forecast soundings....

Potential for a decent chase day tomorrow, especially considering it's not even March yet. I'll summarize my latest thoughts below (taken from my posts on Stormtrack):

Model consistency has been quite impressive. In fact, I don't think the forecasts from the GFS have changed much since last weekend (Day 6). Sure, the exact position of the 500mb low has shifted 100-200 miles at times, but the overall pattern and timing (+/- 6 hrs) has remained relatively consistent. Props to the model, and props to the atmosphere for being in a pattern of relatively low uncertaintly and relatively high predictability...

Not much is new in the 00z runs, and I'm just waiting for the 4km WRF run to post (with explicit convection -- I've found this model to be very good at forecasting storm mode, though I don't think there's much uncertainty in that with this cyclone). I really do hope the NAM verifies better than the GFS, since there are significant differences in the lowest 200mb of the models. The NAM is quite a bit warmer in the boundary layer ahead of the dryline, which creates a low-CINH (or no CINH) environment. In contrast, the GFS keeps the boundary layer much more stable (much higher CINH) owing to considerably lower low-level theta-e. For example, compare the GFS and NAM forecast soundings for Gage, OK, HERE. The GFS seems to be 10-13F cooler near the surface ahead of the warm front than the NAM. The GFS seems to be wanting to keep a thick stratus deck in the warm sector tomorrow (looking at 850mb RH)...

Decent moisture is currently taking the scenic route by advecting through northeastern Mexico before heading northward into western Texas. For example, notice the much deeper moisture on the 00z BRO and MMAN (in far northeastern Mexico) compared to the pitiful CRP soundings. SPC / RUC Mesonalysis at 850mb shows the good moisture taking the scenic route as well...

Speaking of moisture... I'm terribly concerned about moisture and instability north of Oklahoma. Personally, I'm not giving Kansas much thought. That's not to say that I don't think anything will happen there, but I'm more confident staying in OKlahoma and Texas.

The 00z 4km explicit convection WRF is out, it forecasts discrete supercell mode through 6z --> http://wwwt.emc.ncep.noaa.gov/mmb/mmbpll/cent4km/v2/ ... To find storm cores, I like to view the "Total Condensate" product. Check out the splitting supercell in TX from 24h-27h (00z-3z)! No signs of MCS/squall line development until after midnight.