Hi Andrea,
If you look at the NCAR RUC product for that event there were hashed lines over most of the CAPE during the daylight hours....indicating a capping inversion. Also, the sounding showed warming just under 700 MB in sufficient quantity to keep a lid on convection. This is likely one of the main reasons SPC did not extend the outlook area very far south.
Another feature that gets into making specific forecasts was in the works yesterday. Noting the 850 MB winds, they were veered in advance of the convergence boundary through much of south and central Texas. In this particular situation these more westerly winds helped move moisture off and to the east of the dryline. This weakens convergence and limits moisture along the dryline. There are three major ways to break a cap, add moisture, increase convergence and increase lift. Two of these factors were decreasing with time......a big negative. This contributed to the reason I chose not chase this event in Texas.
